AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 420 AM MDT THU APR 6 2006 .SHORT TERM... (TODAY AND TONIGHT) ...A NUMBER OF CONCERNS THIS MORNING...INCLUDING SNOW IN THE MOUNTAINS...FIRE WEATHER CONCERNS EASTERN SLOPES AND PLAINS...AND BLIZZARD POTENTIAL ACROSS NORTHERN EL PASO COUNTY STARTING LATE TONIGHT... WILL ALLOW CURRENT SNOW/BLOWING SNOW ADVISORY TO RUN IT'S COURSE FOR THE EASTERN SAN JUAN MOUNTAINS...EXPIRING AT 6AM. ACCORDING TO THE LATEST RUC ANALYSIS...MOUNTAIN TOP WINDS ARE SHIFTING FROM SOUTHWEST TO NORTHWEST AT THE PRESENT TIME. ALTHOUGH SATELLITE PICTURES INDICATE ANOTHER ROUND OF SNOW MOVING INTO THE SAN JUANS AT THIS TIME...THE SHIFT IN WINDS SHOULD GRADUALLY DIMINISH THE HEAVY SNOW THREAT IN THIS AREA. SO FAR...THE WOLF CREEK SNOTEL SHOWS A GAIN OF ABOUT 1.0 INCHES OF WATER IN THE SNOWPACK SINCE YESTERDAY MORNING. SNOW/BLOWING SNOW ADVISORY FOR THE CENTRAL MOUNTAINS (SAWATCH AND MOSQUITO RANGES) STILL LOOKS GOOD. MODEL PROJECTIONS INDICATE UP TO A FOOT OF SNOW THESE AREAS BY FRIDAY MORNING...WITH THE BULK FALLING THERE THIS AFTERNOON AND THIS EVENING. SO AN ADVISORY THIS AREA UNTIL MIDNIGHT LOOKS GOOD. THE FIRE WEATHER THREAT CONTINUES TO LOOK ON TRACK FOR THE EASTERN SLOPES AND PLAINS TODAY. RHS MAY END UP ON THE MARGINAL SIDE (BOTTOMING OUT RIGHT AROUND 15%) BUT THE WINDS LOOK LIKE THEY'LL MAKE IT OKAY. ALSO...THERE IS THE POTENTIAL FOR MORE DRY LIGHTNING. SO...A RED FLAG WARNING REMAINS IN EFFECT FOR THE EASTERN SLOPES AND PLAINS FROM 10AM TO 9PM TODAY. THE POTENTIAL FOR A BLIZZARD TO DEVELOP ACROSS NORTHERN EL PASO COUNTY SOMETIME LATE TONIGHT STILL LOOKS INTERESTING. BIG DIFFERENCES BETWEEN THE NAM AND GFS SCENARIOS...HOWEVER...WITH THE NAM REALLY NAILING NORTHERN EL PASO COUNTY WITH SNOW STARTING AROUND 12Z AND THE GFS NOT BRINGING IN MUCH MOISTURE AT ALL. BUT...THE NAM FOR MULTIPLE RUNS (EXCLUDING THE 18Z RUN FROM YESTERDAY) HAS SHOWN THIS SCENARIO. THE GFS HAS CONSISTENTLY NOT SHOWN THIS SCENARIO. ONE OF THE NATIONAL MODEL DISCUSSIONS THIS MORNING HAS SUGGESTED THAT THE NAM MAY BE TOO SLOW WITH THE PROGRESSION OF THE LOW...AND THAT THE MORE PROGRESSIVE GFS IS BETTER. BUT...THEN AGAIN...MAYBE THE NAM IS TARGETING THE PALMER DIVIDE BECAUSE IT KNOWS ABOUT THE TERRAIN BETTER. ANYWAY...NOT THE HIGHEST CONFIDENCE FORECAST WITH ALL THE UNCERTAINTY. BUT...THE THREAT IS REAL ENOUGH TO CONTINUE WITH THE BLIZZARD WATCH UNTIL LATER RUNS RESOLVE THINGS (HOPEFULLY). ONE THINGS SEEMS CERTAIN...APPEARS THE WIND WILL START TO BLOW AND BLOW HARD BY EARLY FRIDAY. SEE THE LONG TERM DISCUSSION BELOW FOR MORE ON THAT. LW .LONG TERM... (FRIDAY THROUGH WEDNESDAY) ...POTENTIAL FOR BLIZZARD CONDITIONS FOR THE PALMER DIVIDE AND HIGH WINDS FOR THE SOUTHEAST PLAINS ON FRIDAY THE PRIMARY CONCERNS THIS PACKAGE... STILL SOME MODEL DISCREPANCIES TO DEAL WITH IN THE 36-48 HOUR TIME RANGE AS STRONG VERTICALLY STACKED UPPER LOW ACROSS NORTH CENTRAL KS SHIFTS SOUTHWARD AS JET ENERGY WRAPS AROUND NRN/WRN PERIPHERY OF THE SYSTEM. HOW FAR WEST THE UPPER LOW TRACKS ACROSS KS IS THE MAIN CONUNDRUM...WITH NAM12 THE FARTHEST WEST OF THE SHORT RANGE MODELS. THUS...NAM12 BRINGS A HEALTHY MID LVL THETA-E RIDGE ACROSS EASTERN CO COUPLED WITH MID LVL QG FRONTOGENETICAL FORCING AND EPVS SLIGHTLY BELOW ZERO. THESE FACTORS POINT TO A PERIOD OF MODERATE TO HEAVY PRECIPITATION BANDING UNDER TROWAL WHICH TRANSITIONS ACROSS EASTERN COLORADO FRI MORNING. GFS ON THE OTHER HAND KEEPS THESE PARAMETERS A BIT FARTHER EAST AND NORTH. HAVE GONE WITH A NAM12/GFS MODEL BLEND...GIVEN HPC/S ASSESSMENT THAN NAM12 MAY BE SUFFERING FROM SOME CONVECTIVE FEED BACK. HOWEVER...NAM12 HAS ALSO BEEN CONSISTENT THE PAST COUPLE RUNS WITH THIS SCENARIO...SO ITS DIFFICULT TO DISCOUNT COMPLETELY. MODEL SOUNDINGS OVER THE PALMER DIVIDE SHOW A BRIEF PERIOD OF MODERATE-HEAVY SNOW AS STRONG DIABATIC COOLING COOLS THE VERTICAL TEMPERATURE PROFILE. COMBINED WITH SUSTAINED WINDS AROUND 35 KTS WITH GUSTS IN EXCESS OF 50 KTS POSSIBLE...BLIZZARD CONDITIONS STILL LOOK POSSIBLE DURING THE MORNING HOURS...SO WILL KEEP THE BLIZZARD WATCH GOING FOR NORTHERN EL PASO COUNTY. ANOTHER AREA THAT BEARS WATCHING WILL BE TELLER COUNTY WITH SNOW AMOUNTS APPROACHING THE ADVISORY RANGE. ITS WORTH NOTING HOWEVER THAN GFS IS PORTRAYING SIGNIFICANTLY LESS SNOWFALL FOR THIS REGION...THUS CONFIDENCE STILL ISNT HIGH ENOUGH TO HOIST THE WARNINGS/ADVISORIES JUST YET. SOUNDINGS LOOK FAIRLY WARM FOR THE REMAINDER OF THE SOUTHEAST PLAINS...WITH PCPN FALLING IN THE FORM OF RAIN FOR MOST AREAS...THOUGH COULD BE A BRIEF RAIN/SNOW MIX FRI MORNING ESPECIALLY ACROSS THE NORTHERN PORTIONS OF THE RATON RIDGE. HOWEVER...LOOKS TOO BRIEF TO WARRANT ANY HIGHLIGHTS FOR SNOW FOR THIS AREA. FOR THE REMAINDER OF THE SOUTHEAST PLAINS...SFC GRADIENT QUITE STRONG DURING THE MORNING WITH BOTH MET/MAV GUIDANCE SUGGESTING SUSTAINED SPEEDS OF 35-40 KTS ACROSS THE SOUTHEAST PLAINS. GUSTS IN EXCESS OF 58 MPH LOOK DOABLE AS WINDS AT H7 AROUND 50 KTS OR GREATER...AND SCATTERED SHOWERS MAY HELP TO TRANSPORT HIGHER MOMENTUM ALOFT TO THE SFC. SO WILL HOIST A HIGH WIND WATCH FOR THE SOUTHEAST PLAINS FOR FRIDAY WHICH BLENDS WELL WITH SURROUNDING OFFICES. NOT TO BE LEFT OUT...THE WESTERN MTS WILL SEE SCATTERED SNOW SHOWERS WANING QUICKLY THROUGH THE DAY AS DRIER AIR WORKS INTO THE WEST. CONDITIONS WILL IMPROVE QUICKLY BY FRI NIGHT AS AN UPPER LVL RIDGE TRANSITIONS OVER THE AREA BEHIND THE DEPARTING SYSTEM. ANOTHER WARMING TREND WILL SET IN FOR THE WEEKEND UNDER DRY SOUTHWEST FLOW. GFS BRINGS THE NEXT SHORTWAVE ACROSS CO MONDAY/MONDAY NIGHT BRINGING SHOWERS TO THE WESTERN MOUNTAINS...AND BREEZY CONDITIONS TO THE SOUTHEAST PLAINS. A STRONGER SYSTEM DROPS SOUTHEASTWARD AS IT ENTERS THE WEST COAST TUES NIGHT...AND MOVES ACROSS CENTRAL AZ WEDNESDAY NIGHT...THEN ACROSS CO NEXT THURSDAY. CURRENT GRIDS KEEP POPS ACROSS THE CENTRAL MOUNTAINS THROUGH THE LONG RANGE...AND PLAN TO SPREAD THEM EASTWARD ACROSS THE SOUTHEAST PLAINS FOR THE NEW DAY 8. THANKS TO SURROUNDING OFFICES FOR COLLABORATION TONIGHT. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 10 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR COZ221-COZ222-COZ225-COZ226-COZ227-COZ228-COZ229- COZ230-COZ231-COZ232-COZ233-COZ234-COZ235-COZ236-COZ237. HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR COZ085-COZ086-COZ089-COZ093-COZ094-COZ095-COZ096-COZ097-COZ098- COZ099. SNOW AND BLOWING SNOW ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ058-COZ060. SNOW AND BLOWING SNOW ADVISORY UNTIL 6 AM MDT EARLY THIS MORNING FOR COZ068. BLIZZARD WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR COZ084. && $$ 50/31 co AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE DES MOINES IA 816 PM CDT THU APR 6 2006 .DISCUSSION... MAY BE SEEING A WIDESPREAD CONVECTIVE WIND EVENT OVER SOUTH WESTERN AREAS GIVEN STEEP LOW LEVEL LAPSE RATES HIGH DCAPES AND PLENTY OF 0-6KM BULK SHEAR FOR LONG LIVED STORMS. CONVECTION NOW SPREADING EAST OF THE MO RIVER ALONG INSTABILITY AXIS FROM AROUND SIOUX CITY TO NEAR LAMONI. ALL MODES OF CONVECTION CAN BE EXPECTED AS THE STORMS GET INTO WESTERN FORECAST AREA BUT MAIN LIMITATION WE'LL BE FIGHTING IS WEAKENING OF CAPE IN RUC FORECAST SOUNDINGS AND MOIST ADIABATIC PROFILES. UPDATE TO ALL OF PRODUCT SUITE INCLUDING FLOOD WATCH/TOMMORROWS WIND ADVISORY AND NEW TORNADO WATCH INTO EFFECT THROUGH 3 AM (08 UTC). && .DMX WATCHES/WARNINGS/ADVISORIES... TORNADO WATCH NUMBER 160 SOUTH ALONG AND SOUTH OF HIGHWAY 30 AND WEST OF A JEFFERSON TO WINTERSET TO LAMONI LINE. FLOOD WATCH CONTINUES ALONG AND NORTH OF HIGHWAY 30 TONIGHT THROUGH FRIDAY MORNING. WIND ADVISORY OVER ENTIRE CWA FROM 09Z-24Z/07 && $$ RUSSELL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1101 AM CDT THU APR 6 2006 .UPDATE... LATEST MESO TRENDS SUPPORT 12Z MODEL GUIDANCE...IN DELAYING THE DRY LINE FRONT PASSAGE ACROSS THE FORECAST AREA THIS AFTERNOON AND EARLY EVENING. THIS WILL SHIFT RISK FOR SIGNIFICANT SEVERE WEATHER A BIT FURTHER WEST...TO INCLUDE THE GREATER WICHITA AREA. RUC DATA SUGGESTS CAP WILL ERODE/BREAK VERY QUICKLY FOR SURFACE BASED CONVECTION BY 18Z ALONG THE DRY LINE TO THE WEST OF WICHITA...THEN QUICKLY EVOLVE NORTHEASTWARD THRU THE AFTERNOON. WILL BE UPDATING OUTLOOK AND FORECAST GRIDS TO SHOW THIS LATEST TREND IN EXPECTATIONS. ALSO LOOKS LIKE A WIND AND INCREASED FIRE DANGER RISK BY LATE AFTERNOON AND EARLY EVENING FOR AREAS OF CENTRAL AND SOUTH CENTRAL KANSAS BEHIND THE DRY LINE. BLOWING DUST ALREADY OBSERVED ACROSS THE TEXAS PANHANDLE. UPDATES OUT SHORTLY... KED && .PREV DISCUSSION... /ISSUED 908 AM CDT THU APR 6 2006/ UPDATE... UPGRADE TO HAZARDOUS WEATHER OUTLOOK AND FORECAST NEEDED TO HIGHLIGHT THE SIGNIFICANT RISK FOR SEVERE WEATHER ACROSS THE EASTERN HALF OF THE FORECAST AREA THIS AFTERNOON. THE SCENARIO IS NOT THAT MUCH DIFFERENT THAN ONE WEEK AGO (LAST THURSDAY) WITH A RISK FOR A FEW STRONG TORNADOES. A LOCAL CONFERENCE CALL TO AREA EMERGENCY MANAGEMENT WILL LIKELY BE COMING LATE THIS MORNING. KED && PREV DISCUSSION... /ISSUED 323 AM CDT THU APR 6 2006/ DISCUSSION... FORECAST PROBLEMS: 1) SEVERE CONVECTIVE POTENTIAL OVER PRIMARILY SE KS THIS AFTERNOON. 2) SOUTHERLY WINDS ACHIEVING ADVISORY CRITERIA THIS AFTERNOON OVER ALL OF FORECAST AREA. TODAY: VERY ACTIVE DAY AWAITS THE NEIGHBORHOOD AS INTENSE UPSTAIRS LOW MOVES SE FROM WY ACROSS NW KS. ALL 3 "PRIMARY" MODELS AGREE QUITE ON ALL FACETS OF THIS FEATURE. AS SUCH...FORECASTER CONFIDENCE IS FAIRLY HIGH WITH RESPECT TO SIGNIFICANT WEATHER POTENTIAL IN TERMS OF SEVERE CONVECTION & SOUTHERLY WINDS ACHIEVING ADVISORY POTENTIAL. ONE FEATURE THAT MUST BE WATCHED CLOSELY IS POSITIONING OF WHAT NOW APPEARS TO BE A PACIFIC COLD FRONT SURGING EAST TOWARD WRN CORRIDOR LATE THIS MORNING. WITH SYSTEM ASSUMING MORE OF A "STACKED" VARIANT LATE THIS AFTERNOON...SFC LOW WILL DEEPEN MARKEDLY WHICH SHOULD ENABLE THE PACIFIC FRONT TO ACCELERATE THIS AFTERNOON. AS SUCH HAVE TAKEN CONSERVATIVE APPROACH TO POPS WITH HIGHEST (~40%) ASSIGNED TO NE CORRIDOR WHERE NOT ONLY CLOSER TO RICH SFC-850MB MOISTURE AXIS BUT ALSO TO LEFT EXIT REGION OF 300- MB JET MAX SURGING EAST ACROSS OK. DEEP-LAYER SHEAR VERY SUPPORTIVE OF SUPER-CELLULAR CONVECTION WITH LARGE HAIL & DAMAGING WINDS BOTH THREATS. A 2ND CONCERN IS STRENGTHENING SOUTHERLY WINDS. MODEL SOUNDINGS ALL DEPICT VERY STEEP LAPSE RATES TO NEARLY 700-MB THAT ARE NEARLY DRY ADIABATIC. THINKING IS THAT CLOUD COVER WILL BE SUFFICIENT TO PREVENT MAX MIXING POTENTIAL BUT CERTAINLY BELIEVE WIND ADVISORY IS GOOD CALL & WILL RETAIN. WIND ADVISORY TO REMAIN IN EFFECT FROM GENERALLY 11AM TO 7PM. TONIGHT: WITH PACIFIC FRONT CONTINUING EWD SURGE ACROSS KS/MO BORDER SEVERE CONVECTIVE THREAT TO LIKEWISE SHIFT NE-E OF FORECAST AREA. FOCUS THEN SHIFTS TO POTENTIAL OF WRAP-AROUND ASSOCIATED SHRA THAT WILL MIGRATE S/SE TOWARD PRIMARILY CENTRAL KS LATER TONIGHT. HAVE RETAINED ~30% POPS ACROSS CENTRAL KS. FRIDAY: MODELS CONTINUE INDICATING THAT UPSTAIRS LOW WILL GRADUALLY FILL & MOVE SE ACROSS ERN KS. SFC-850MB COHORTS TO THEREFORE MOVE IN LIKE MANNER WITH VERY TIGHT NORTHERLY GRADIENT ACROSS CENTRAL KS. VERY LIKELY 2ND WIND ADVISORY WILL BE REQUIRED FOR CENTRAL KS FRI AFTERNOON...BUT BEING A 3RD PERIOD FORECAST...WILL HOLD OFF ISSUANCE TO ALLOW SUCCESSORS CHANCE TO STUDY SUBSEQUENT MODEL RUNS. WITH SFC LOW MOVING SE ACROSS ERN KS...WRAP-AROUND ASSOCIATED SHRA TO SPREAD S/SE ACROSS REMAINDER OF OFRECAST AREA & HAVE GRADUALLY INCREASED POPS TO 30-40% MOST AREAS. FRIDAY NIGHT: BROAD INVERTED SFC RIDGE BUILDS SOUTH FROM NRN PLAINS INTO KS THEREBY SHUNTING ALL PRECIPITATION SE OF FORECAST AREA. EXTENDED: AFTER DRY WEEKEND...NEXT CHANCE FOR TSRA STILL APPEARS SLATED FOR NEXT MONDAY AFTERNOON-TUESDAY NIGHT AS NEXT UPSTAIRS TROF DEEPENS OVER AZ. && PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 81 46 61 40 / 20 20 30 30 HUTCHINSON 80 44 60 38 / 20 20 30 30 NEWTON 81 45 63 39 / 30 20 30 30 ELDORADO 81 46 64 40 / 30 20 30 30 WINFIELD-KWLD 84 47 64 41 / 30 10 30 30 RUSSELL 76 40 49 33 / 30 30 40 30 GREAT BEND 77 40 50 34 / 20 30 40 30 SALINA 80 44 60 35 / 30 30 40 30 MCPHERSON 80 44 61 37 / 30 30 30 30 COFFEYVILLE 82 50 69 40 / 40 20 20 20 CHANUTE 80 49 68 38 / 40 30 30 20 IOLA 79 48 68 38 / 40 30 30 20 PARSONS-KPPF 81 50 69 39 / 40 30 20 20 && .ICT WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 7 PM THURSDAY FOR KSZ051>053-067>072-082-083- 091>096-098>100. WIND ADVISORY UNTIL 7 PM THURSDAY FOR KSZ032-033-047>050. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 940 PM EDT THU APR 6 2005 .UPDATE...SFC/RUC/SATELLITE/UPPER AIR AND RADAR ANALYSIS SHOWING ZONE OF STEEPER LAPSE RATES IN THE 600-500MB LAYER WITH DEEPER MOISTURE WELL NORTH OF CENTRAL PLAINS WARM FRONT HAS ALLOWED THE SPRINKLES TO BUILD INTO SCATTERED RAIN SHOWERS. THIS IS OCCURRING IN STRENGTHENING DEFORMATION ZONE BETWEEN ONE UPPER LOW NEAR JAMES BAY...AND ANOTHER (PRODUCING SEVERE WEATHER IN THE CENTRAL PLAINS) ENTERING THE IOWA/MO BORDER. OTHER RAIN SHOWERS WERE DEVELOPING INTO SRN WISCONSIN...AND EXPECT BOTH AREAS OF RAIN SHOWERS TO TRY AND MERGE ACROSS MUCH OF NORTHER LOWER...MAINLY SOUTH OF M-68 INTO THE OVERNIGHT HOURS. HAVE INCREASED POPS INTO THE 40% RANGE IN THIS AREA. LATE TONIGHT...COLD FRONT ASSOCIATED WITH UPPER LOW TO OUR NORTH DROPS INTO THE NORTHERN CWA...AND COLDER AIR AND STRONGER NORTHERLY WINDS WILL ARRIVE IN IT'S WAKE. THIS WILL GRADUALLY DRY OUT THE ATMOSPHERE BY TOMORROW MORNING...AND PUSH ANY CHANCE OF RAIN TO OUR SOUTH. ALSO...THE NORTHERLY WINDS AND DEVELOPING OVER-LAKE INSTABILITY WILL RESULT IN GUSTY WINDS TO 25KTS...LOCALLY HIGHER. THIS WILL WARRANT THE ISSUANCE OF SMALL CRAFT ADVISORIES FOR ALL MARINE ZONES. MADE SOME TWEAKS TO THE TEMPS...AS CLOUDS SHOULD KEEP TEMPS WARM UNTIL COLD FRONT ARRIVES LATE. SMD && .PREV DISCUSSION ISSUED AT 707 PM EDT THU APR 6 2005 UPDATE...QUICK UPDATE FOR SCATTERED SPRINKLES THAT ARE DEVELOPING OVER THE AREA. THIS IS OCCURRING IN A ZONE OF STEEPER (6.5C/KM) LAPSE RATES IN THE DEEPER MID LEVEL MOISTURE BETWEEN 600-500MB. THIS ACTIVITY IS WELL NORTH OF A WARM FRONT IN THE CENTRAL PLAINS WHICH WAS PRODUCING ELEVATED SHOWERS AND THUNDERSTORMS FROM FAR NE SOUTH DAKOTA AND SRN MINNESOTA...AND IN CENTRAL ILLINOIS. SOME OF THIS ACTION MAY TRY AND SNEAK INTO OUR FAR SOUTHERN CWA LATE TONIGHT BUT WITHOUT THE THUNDER...AS ALL OF THE INSTABILITY WILL BE WELL SOUTH OF US. WILL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT FEW HOURS FOR POSSIBLE OTHER UPDATES LATER TONIGHT. SMD && PREV DISCUSSION ISSUED AT 430 PM EDT THU APR 6 2005 DISCUSSION...RUC ANALYSIS AND VIS/IR/WV IMAGERY SHOW SURFACE RIDGE AXIS CONTINUING TO HANG TOUGH ACROSS MICHIGAN THIS AFTERNOON. 6KFT-10KFT CLOUD DECK CONTINUES TO SPREAD OVER THE AREA AHEAD OF A STRONG LOW PRESSURE SYSTEM OVER THE GREAT PLAINS. SHOWERS AND THUNDERSTORMS ARE DEVELOPING AHEAD OF THE WARM FRONT ACROSS IOWA...ILLINOIS...INDIANA. MEANWHILE...A COLD FRONT EXTENDING FROM LOW PRESSURE OVER QUEBEC IS SLOWLY MAKING ITS WAY SOUTHWARD ACROSS CENTRAL ONTARIO AND NORTHERN LAKE SUPERIOR. THROUGH FRIDAY...MAIN FORECAST CONCERNS WILL INCLUDE CLOUD COVER AND PRECIP CHANCES ACROSS OUR FAR SOUTHERN CWA. TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO THE EAST TONIGHT AS THE NORTHERN STREAM COLD FRONT DROPS SOUTHWARD. WARM ADVECTION MID-LEVEL CLOUD DECK WILL THICKEN OVERNIGHT AHEAD OF THE COLD FRONT ACROSS THE CWA...BUT THE DEEPEST MOISTURE WILL REMAIN FAR TO OUR SOUTH. GFS/NAM ARE PROJECTING THE COLD FRONT TO REACH EASTERN UPPER BY ABOUT THE 06Z TIMEFRAME AND THE TRAVERSE CITY AND ALPENA AREAS BY 12Z. MUCH DRIER AIR (850-700MB RH 10-20 PCT) WILL RESIDE BEHIND THIS FRONT WHICH WILL HELP TO CLEAR OUT MOST OF THE CLOUD COVER ONCE THE FRONT PASSES. AREAS TO THE SOUTH OF THE FRONT DURING THE NIGHT WILL REMAIN MOSTLY CLOUDY. THERE IS A CHANCE FOR A FEW RAIN SHOWERS...MOSTLY CONFINED ALONG AND TO THE SOUTH OF M-55. THIS IS WHERE THE NAM AND GFS DIFFER...ESPECIALLY AFTER THE 06Z TIMEFRAME. THE GFS SHOWS SIGNIFICANTLY MORE LOW LEVEL MOISTURE IN ITS THERMODYNAMIC PROFILE THAN THE NAM. THE GFS ALSO CUTS OFF THE MOISTURE AT THE -5C LEVEL WHILE THE NAM ENDS AT THE 0C MARK. THEREFORE...BELIEVE ANY PRECIP THAT DOES FALL WILL BE OF THE LIQUID VARIETY. WITH THIS MOISTURE DIFFERENCE...HAVE TAKEN A BLEND OF THE TWO MODELS AND LEFT A 30 POP ALONG AND SOUTH OF M-55. FRIDAY...THE COLD FRONT WILL CONTINUE TO MAKE ITS WAY SOUTHWARD TOMORROW...BUT WILL NOT CLEAR THE CWA UNTIL THE 18Z-21Z TIMEFRAME. MUCH OF THE MID-LEVEL MOISTURE WILL HAVE PUSHED TO THE SOUTH BY 18Z...BUT NAM/GFS BOTH INDICATED A SHARP CUTOFF BETWEEN THE RELATIVELY DEEPER MOISTURE JUST TO THE SOUTH OF THE CWA. BECAUSE OF THIS SHARP MOISTURE CONTRAST...HAVE KEPT A CHANCE FOR RAIN SHOWERS (MOISTURE WILL STRUGGLE TO REACH -10C) ALONG AND SOUTH OF M-55. TEMPERATURES BEHIND THE FRONT WILL BE SIGNIFICANTLY COOLER...AS 850MB TEMPS WILL FALL TO -10C BY 00Z (AND 18Z ACROSS EASTERN UPPER). THIS WOULD PUT DELTA T'S APPROX -10 TO -12C ACROSS LAKE SUPERIOR...SLIGHTLY TOO WARM FOR LAKE EFFECT SNOW DEVELOPMENT. NORTHERLY WINDS BEHIND THE FRONT WILL BE GUSTY TOMORROW WITH A SHARP PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE NW AND LOW PRESSURE TO THE SE. NAM AND GFS SOUNDINGS SHOW WINDS APPROACHING 35 AND 25 KTS RESPECTIVELY WITHIN THE MIXED LAYER ACROSS NW LOWER BY THE AFTERNOON. THESE CONDITIONS WOULD WARRANT AT LEAST A SMALL CRAFT ADVISORY ALONG N-S ORIENTED LAKE MICHIGAN AND LAKE HURON SHORELINES. MPC .LONG TERM...MODELS ARE IN GOOD AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK WITH THE UPPER LEVEL PATTERN REMAINING HIGHLY AMPLIFIED. UPPER LEVEL TROUGH WILL CROSS THE REGION FRIDAY AND FRIDAY NIGHT WITH HIGH PRESSURE AND AN UPPER LEVEL RIDGE BUILDING IN BEHIND THE TROUGH. MODELS DIFFER SLIGHTLY ON AMPLIFICATION OF UPPER LEVEL RIDGE AT THE BEGINNING OF NEXT WEEK WHICH WILL RESULT IN A BIT OF UNCERTAINTY IN THE CLOUDS AND TEMPERATURES. MAIN CONCERNS IN THE LONG TERM CENTER ON CLOUDS/CHANCES OF PRECIPITATION ACROSS EASTERN UPPER FRIDAY NIGHT/SATURDAY MORNING AND RAIN SHOWERS/THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. FRIDAY NIGHT...LOW PRESSURE WILL CONTINUE TO DROP INTO THE MID MISSISSIPPI VALLEY WITH THE UPPER LEVEL TROUGH CROSSING MICHIGAN BEFORE MIDNIGHT. WRAP AROUND MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW IN WESTERN QUEBEC WILL BRUSH THE NORTHER REACHES OF THE CWA WITH 850 MB TEMPERATURES BEING THE BIGGEST CONCERN. BY 06Z 850 MB TEMPERATURES WILL HAVE DECREASED TO -10C TO -12C CREATING LAKE TO 850 MB DELTA T/S IN THE 13C TO 15C RANGE. ALTHOUGH MODEL SOUNDINGS INDICATE THERE WILL BE PLENTY OF DRY AIR AOB 900 MB WILL LIMIT THE LAKE EFFECT POTENTIAL. NORTHERLY WINDS WILL ALSO LIMIT THE POTENTIAL...HOWEVER MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW WILL DROP A BIT FURTHER SOUTH DURING THE NIGHT RESULTING IN A BIT BETTER LAKE EFFECT POTENTIAL. WITH THAT BEING SAID WILL CUT BACK FROM SNOW SHOWERS TO FLURRIES ACROSS THE NW AND NNW LAKE EFFECT PRONE AREAS OF EASTERN UPPER AND NORTHERN LOWER. SATURDAY AND SATURDAY NIGHT...THE UPPER LEVEL TROUGH SWINGS EAST OF THE REGION SATURDAY MORNING WITH SOME WRAP AROUND MOISTURE BEHIND THE UPPER LEVEL LOW PREPARING TO ENTER THE REGION. 850 MB TEMPERATURES WILL BE IN THE -8C RANGE WITH LAKE TO 850 MB DELTA T/S AROUND 11C. THIS BRINGS UP THE POTENTIAL FOR LAKE EFFECT CLOUDS AND SNOW DURING THE MORNING HOURS. THERE ARE SEVERAL FACTORS WHICH WILL LIMIT THE POTENTIAL FOR LAKE EFFECT...STARTING WITH THE DRY AIR INTRUDING AOB 850 MB. 850-700 MB LAYER RH WILL BE 50-60 PCT WHILE 700-500 MB LAYER RH WILL ONLY BE 30 PCT OR LESS. WITH THE AVAILABLE MOISTURE AOB 700 MB LAKE EFFECT WILL BE KEPT TO A MINIMUM AS DENDRITIC GROWTH AND SEEDING PROCESSES WILL BE UNABLE TO TAP INTO AIR COLDER THAN -10C. WITH THAT IN MIND HAVE SCALED BACK THE SNOW SHOWERS TO FLURRIES AND LIMITED THE AREAS TO THOSE FAVORED IN NW AND NNW FLOW. SATURDAY AFTERNOON THROUGH SATURDAY NIGHT WEAK WAA OVERSPREADS THE REGION AND RAISES THE 850 MB TEMPERATURE TO AROUND -4C BY 00Z. WITH THE 850 MB TEMPERATURE INCREASING THE LAKE TO 850 MB DELTA T WILL BE UNDER 10C AND ELIMINATE THE POSSIBILITY OF LAKE EFFECT SNOW. SUNDAY AND SUNDAY NIGHT...HIGH PRESSURE AND A RELATIVELY FLAT UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE AREA WITH THE MAIN MOISTURE AXIS ACROSS SOUTHERN ONTARIO. WEAK WAA WILL STRENGTHEN INTO SUNDAY NIGHT WITH 850 MB TEMPERATURES CLIMBING TO 4C TOWARD DAYBREAK MONDAY. WITH THE HIGH PRESSURE...UPPER LEVEL RIDGE AND CLIMBING 850 MB TEMPERATURES WILL EXPECT NO PRECIPITATION WITH THE GREATEST AMOUNT OF CLOUDS OVER EASTERN UPPER DUE TO THE MOISTURE AXIS. MONDAY AND THE REMAINDER OF THE EXTENDED...AXIS OF UPPER LEVEL RIDGE WILL PUSH INTO THE WESTERN GREAT LAKES WITH HIGH TEMPERATURES SLIGHTLY ABOVE NORMAL. BEGINNING OF THE WEEK WILL REMAIN TRANQUIL AS HIGH PRESSURE WILL KEEP THE MAIN BULK OF THE MOISTURE NORTH OF THE AREA UNTIL THE MIDDLE OF THE WEEK. TUESDAY EVENING THE NEXT LOW PRESSURE WILL ENTER THE REGION BRINGING ANOTHER ROUND OF RAIN SHOWERS. THUNDERSTORMS WILL REMAIN A POSSIBILITY...BUT WITH MODEL SOUNDINGS INDICATING A LACK OF INSTABILITY WILL REMAIN WITH THE RAIN SHOWERS ATTM. LOW PRESSURE CONTINUES TO PUSH ACROSS THE REGION THROUGH THURSDAY MORNING WHEN HIGH PRESSURE AND A MINOR UPPER LEVEL RIDGE ONCE AGAIN ENTER THE AREA. && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 930 PM EDT THU APR 6 2006 .UPDATE... AT 01Z KGRR RADAR IMAGERY AND SFC OBS INDICATE DRY CONDITIONS PREVAIL ACROSS OUR AREA. THE 00Z DTX SOUNDING SHOWS A VERY DRY AIRMASS REMAINS IN PLACE AND I THINK THE ONSET OF RAIN SHOWERS OVER OUR SOUTHERN CWA WILL BE DELAYED A BIT UNTIL AFTER MIDNIGHT AND BECOME MORE LIKELY TOWARDS DAYBREAK FRIDAY. LATEST SHORT RANGE GUIDANCE INCLUDING THE RUC-13 STILL SHOW RAIN SHOWERS WILL DEVELOP OVER OUR SOUTHERN CWA AFTER MIDNIGHT AND CENTRAL CWA VERY LATE. THIS AS THE WARM FRONT LIFTS NORTH AND CLOSER TO OUR AREA AND SFC DEW POINTS RISE INTO THE LOWER TO MIDDLE 40S. WE WILL ISSUE A ZONE UPDATE TO MENTION THAT RAIN WILL NOT DEVELOP UNTIL AFTER MIDNIGHT CENTRAL AND SOUTH. WE WILL ALSO TRIM BACK POPS SOMEWHAT FOR THE OVERNIGHT PERIOD... ESPECIALLY ACROSS OUR CENTRAL CWA. LIGHT RAIN SHOWERS WHICH ARE MOVING EAST OVER LAKE MI CONTINUE TO DISSIPATE AS THEY ENCOUNTER THE DRY AIR MASS IN PLACE OVER OUR AREA. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ LAURENS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 707 PM EDT THU APR 6 2005 .UPDATE...QUICK UPDATE FOR SCATTERED SPRINKLES THAT ARE DEVELOPING OVER THE AREA. THIS IS OCCURRING IN A ZONE OF STEEPER (6.5C/KM) LAPSE RATES IN THE DEEPER MID LEVEL MOISTURE BETWEEN 600-500MB. THIS ACTIVITY IS WELL NORTH OF A WARM FRONT IN THE CENTRAL PLAINS WHICH WAS PRODUCING ELEVATED SHOWERS AND THUNDERSTORMS FROM FAR NE SOUTH DAKOTA AND SRN MINNESOTA...AND IN CENTRAL ILLINOIS. SOME OF THIS ACTION MAY TRY AND SNEAK INTO OUR FAR SOUTHERN CWA LATE TONIGHT BUT WITHOUT THE THUNDER...AS ALL OF THE INSTABILITY WILL BE WELL SOUTH OF US. WILL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT FEW HOURS FOR POSSIBLE OTHER UPDATES LATER TONIGHT. SMD && .PREV DISCUSSION ISSUED AT 430 PM EDT THU APR 6 2005 DISCUSSION...RUC ANALYSIS AND VIS/IR/WV IMAGERY SHOW SURFACE RIDGE AXIS CONTINUING TO HANG TOUGH ACROSS MICHIGAN THIS AFTERNOON. 6KFT-10KFT CLOUD DECK CONTINUES TO SPREAD OVER THE AREA AHEAD OF A STRONG LOW PRESSURE SYSTEM OVER THE GREAT PLAINS. SHOWERS AND THUNDERSTORMS ARE DEVELOPING AHEAD OF THE WARM FRONT ACROSS IOWA...ILLINOIS...INDIANA. MEANWHILE...A COLD FRONT EXTENDING FROM LOW PRESSURE OVER QUEBEC IS SLOWLY MAKING ITS WAY SOUTHWARD ACROSS CENTRAL ONTARIO AND NORTHERN LAKE SUPERIOR. THROUGH FRIDAY...MAIN FORECAST CONCERNS WILL INCLUDE CLOUD COVER AND PRECIP CHANCES ACROSS OUR FAR SOUTHERN CWA. TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO THE EAST TONIGHT AS THE NORTHERN STREAM COLD FRONT DROPS SOUTHWARD. WARM ADVECTION MID-LEVEL CLOUD DECK WILL THICKEN OVERNIGHT AHEAD OF THE COLD FRONT ACROSS THE CWA...BUT THE DEEPEST MOISTURE WILL REMAIN FAR TO OUR SOUTH. GFS/NAM ARE PROJECTING THE COLD FRONT TO REACH EASTERN UPPER BY ABOUT THE 06Z TIMEFRAME AND THE TRAVERSE CITY AND ALPENA AREAS BY 12Z. MUCH DRIER AIR (850-700MB RH 10-20 PCT) WILL RESIDE BEHIND THIS FRONT WHICH WILL HELP TO CLEAR OUT MOST OF THE CLOUD COVER ONCE THE FRONT PASSES. AREAS TO THE SOUTH OF THE FRONT DURING THE NIGHT WILL REMAIN MOSTLY CLOUDY. THERE IS A CHANCE FOR A FEW RAIN SHOWERS...MOSTLY CONFINED ALONG AND TO THE SOUTH OF M-55. THIS IS WHERE THE NAM AND GFS DIFFER...ESPECIALLY AFTER THE 06Z TIMEFRAME. THE GFS SHOWS SIGNIFICANTLY MORE LOW LEVEL MOISTURE IN ITS THERMODYNAMIC PROFILE THAN THE NAM. THE GFS ALSO CUTS OFF THE MOISTURE AT THE -5C LEVEL WHILE THE NAM ENDS AT THE 0C MARK. THEREFORE...BELIEVE ANY PRECIP THAT DOES FALL WILL BE OF THE LIQUID VARIETY. WITH THIS MOISTURE DIFFERENCE...HAVE TAKEN A BLEND OF THE TWO MODELS AND LEFT A 30 POP ALONG AND SOUTH OF M-55. FRIDAY...THE COLD FRONT WILL CONTINUE TO MAKE ITS WAY SOUTHWARD TOMORROW...BUT WILL NOT CLEAR THE CWA UNTIL THE 18Z-21Z TIMEFRAME. MUCH OF THE MID-LEVEL MOISTURE WILL HAVE PUSHED TO THE SOUTH BY 18Z...BUT NAM/GFS BOTH INDICATED A SHARP CUTOFF BETWEEN THE RELATIVELY DEEPER MOISTURE JUST TO THE SOUTH OF THE CWA. BECAUSE OF THIS SHARP MOISTURE CONTRAST...HAVE KEPT A CHANCE FOR RAIN SHOWERS (MOISTURE WILL STRUGGLE TO REACH -10C) ALONG AND SOUTH OF M-55. TEMPERATURES BEHIND THE FRONT WILL BE SIGNIFICANTLY COOLER...AS 850MB TEMPS WILL FALL TO -10C BY 00Z (AND 18Z ACROSS EASTERN UPPER). THIS WOULD PUT DELTA T'S APPROX -10 TO -12C ACROSS LAKE SUPERIOR...SLIGHTLY TOO WARM FOR LAKE EFFECT SNOW DEVELOPMENT. NORTHERLY WINDS BEHIND THE FRONT WILL BE GUSTY TOMORROW WITH A SHARP PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE NW AND LOW PRESSURE TO THE SE. NAM AND GFS SOUNDINGS SHOW WINDS APPROACHING 35 AND 25 KTS RESPECTIVELY WITHIN THE MIXED LAYER ACROSS NW LOWER BY THE AFTERNOON. THESE CONDITIONS WOULD WARRANT AT LEAST A SMALL CRAFT ADVISORY ALONG N-S ORIENTED LAKE MICHIGAN AND LAKE HURON SHORELINES. MPC .LONG TERM...MODELS ARE IN GOOD AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK WITH THE UPPER LEVEL PATTERN REMAINING HIGHLY AMPLIFIED. UPPER LEVEL TROUGH WILL CROSS THE REGION FRIDAY AND FRIDAY NIGHT WITH HIGH PRESSURE AND AN UPPER LEVEL RIDGE BUILDING IN BEHIND THE TROUGH. MODELS DIFFER SLIGHTLY ON AMPLIFICATION OF UPPER LEVEL RIDGE AT THE BEGINNING OF NEXT WEEK WHICH WILL RESULT IN A BIT OF UNCERTAINTY IN THE CLOUDS AND TEMPERATURES. MAIN CONCERNS IN THE LONG TERM CENTER ON CLOUDS/CHANCES OF PRECIPITATION ACROSS EASTERN UPPER FRIDAY NIGHT/SATURDAY MORNING AND RAIN SHOWERS/THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. FRIDAY NIGHT...LOW PRESSURE WILL CONTINUE TO DROP INTO THE MID MISSISSIPPI VALLEY WITH THE UPPER LEVEL TROUGH CROSSING MICHIGAN BEFORE MIDNIGHT. WRAP AROUND MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW IN WESTERN QUEBEC WILL BRUSH THE NORTHER REACHES OF THE CWA WITH 850 MB TEMPERATURES BEING THE BIGGEST CONCERN. BY 06Z 850 MB TEMPERATURES WILL HAVE DECREASED TO -10C TO -12C CREATING LAKE TO 850 MB DELTA T/S IN THE 13C TO 15C RANGE. ALTHOUGH MODEL SOUNDINGS INDICATE THERE WILL BE PLENTY OF DRY AIR AOB 900 MB WILL LIMIT THE LAKE EFFECT POTENTIAL. NORTHERLY WINDS WILL ALSO LIMIT THE POTENTIAL...HOWEVER MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW WILL DROP A BIT FURTHER SOUTH DURING THE NIGHT RESULTING IN A BIT BETTER LAKE EFFECT POTENTIAL. WITH THAT BEING SAID WILL CUT BACK FROM SNOW SHOWERS TO FLURRIES ACROSS THE NW AND NNW LAKE EFFECT PRONE AREAS OF EASTERN UPPER AND NORTHERN LOWER. SATURDAY AND SATURDAY NIGHT...THE UPPER LEVEL TROUGH SWINGS EAST OF THE REGION SATURDAY MORNING WITH SOME WRAP AROUND MOISTURE BEHIND THE UPPER LEVEL LOW PREPARING TO ENTER THE REGION. 850 MB TEMPERATURES WILL BE IN THE -8C RANGE WITH LAKE TO 850 MB DELTA T/S AROUND 11C. THIS BRINGS UP THE POTENTIAL FOR LAKE EFFECT CLOUDS AND SNOW DURING THE MORNING HOURS. THERE ARE SEVERAL FACTORS WHICH WILL LIMIT THE POTENTIAL FOR LAKE EFFECT...STARTING WITH THE DRY AIR INTRUDING AOB 850 MB. 850-700 MB LAYER RH WILL BE 50-60 PCT WHILE 700-500 MB LAYER RH WILL ONLY BE 30 PCT OR LESS. WITH THE AVAILABLE MOISTURE AOB 700 MB LAKE EFFECT WILL BE KEPT TO A MINIMUM AS DENDRITIC GROWTH AND SEEDING PROCESSES WILL BE UNABLE TO TAP INTO AIR COLDER THAN -10C. WITH THAT IN MIND HAVE SCALED BACK THE SNOW SHOWERS TO FLURRIES AND LIMITED THE AREAS TO THOSE FAVORED IN NW AND NNW FLOW. SATURDAY AFTERNOON THROUGH SATURDAY NIGHT WEAK WAA OVERSPREADS THE REGION AND RAISES THE 850 MB TEMPERATURE TO AROUND -4C BY 00Z. WITH THE 850 MB TEMPERATURE INCREASING THE LAKE TO 850 MB DELTA T WILL BE UNDER 10C AND ELIMINATE THE POSSIBILITY OF LAKE EFFECT SNOW. SUNDAY AND SUNDAY NIGHT...HIGH PRESSURE AND A RELATIVELY FLAT UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE AREA WITH THE MAIN MOISTURE AXIS ACROSS SOUTHERN ONTARIO. WEAK WAA WILL STRENGTHEN INTO SUNDAY NIGHT WITH 850 MB TEMPERATURES CLIMBING TO 4C TOWARD DAYBREAK MONDAY. WITH THE HIGH PRESSURE...UPPER LEVEL RIDGE AND CLIMBING 850 MB TEMPERATURES WILL EXPECT NO PRECIPITATION WITH THE GREATEST AMOUNT OF CLOUDS OVER EASTERN UPPER DUE TO THE MOISTURE AXIS. MONDAY AND THE REMAINDER OF THE EXTENDED...AXIS OF UPPER LEVEL RIDGE WILL PUSH INTO THE WESTERN GREAT LAKES WITH HIGH TEMPERATURES SLIGHTLY ABOVE NORMAL. BEGINNING OF THE WEEK WILL REMAIN TRANQUIL AS HIGH PRESSURE WILL KEEP THE MAIN BULK OF THE MOISTURE NORTH OF THE AREA UNTIL THE MIDDLE OF THE WEEK. TUESDAY EVENING THE NEXT LOW PRESSURE WILL ENTER THE REGION BRINGING ANOTHER ROUND OF RAIN SHOWERS. THUNDERSTORMS WILL REMAIN A POSSIBILITY...BUT WITH MODEL SOUNDINGS INDICATING A LACK OF INSTABILITY WILL REMAIN WITH THE RAIN SHOWERS ATTM. LOW PRESSURE CONTINUES TO PUSH ACROSS THE REGION THROUGH THURSDAY MORNING WHEN HIGH PRESSURE AND A MINOR UPPER LEVEL RIDGE ONCE AGAIN ENTER THE AREA. && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 430 PM EDT THU APR 6 2005 .DISCUSSION...RUC ANALYSIS AND VIS/IR/WV IMAGERY SHOW SURFACE RIDGE AXIS CONTINUING TO HANG TOUGH ACROSS MICHIGAN THIS AFTERNOON. 6KFT-10KFT CLOUD DECK CONTINUES TO SPREAD OVER THE AREA AHEAD OF A STRONG LOW PRESSURE SYSTEM OVER THE GREAT PLAINS. SHOWERS AND THUNDERSTORMS ARE DEVELOPING AHEAD OF THE WARM FRONT ACROSS IOWA...ILLINOIS...INDIANA. MEANWHILE...A COLD FRONT EXTENDING FROM LOW PRESSURE OVER QUEBEC IS SLOWLY MAKING ITS WAY SOUTHWARD ACROSS CENTRAL ONTARIO AND NORTHERN LAKE SUPERIOR. THROUGH FRIDAY...MAIN FORECAST CONCERNS WILL INCLUDE CLOUD COVER AND PRECIP CHANCES ACROSS OUR FAR SOUTHERN CWA. TONIGHT...SURFACE HIGH PRESSURE WILL PUSH OFF TO THE EAST TONIGHT AS THE NORTHERN STREAM COLD FRONT DROPS SOUTHWARD. WARM ADVECTION MID-LEVEL CLOUD DECK WILL THICKEN OVERNIGHT AHEAD OF THE COLD FRONT ACROSS THE CWA...BUT THE DEEPEST MOISTURE WILL REMAIN FAR TO OUR SOUTH. GFS/NAM ARE PROJECTING THE COLD FRONT TO REACH EASTERN UPPER BY ABOUT THE 06Z TIMEFRAME AND THE TRAVERSE CITY AND ALPENA AREAS BY 12Z. MUCH DRIER AIR (850-700MB RH 10-20 PCT) WILL RESIDE BEHIND THIS FRONT WHICH WILL HELP TO CLEAR OUT MOST OF THE CLOUD COVER ONCE THE FRONT PASSES. AREAS TO THE SOUTH OF THE FRONT DURING THE NIGHT WILL REMAIN MOSTLY CLOUDY. THERE IS A CHANCE FOR A FEW RAIN SHOWERS...MOSTLY CONFINED ALONG AND TO THE SOUTH OF M-55. THIS IS WHERE THE NAM AND GFS DIFFER...ESPECIALLY AFTER THE 06Z TIMEFRAME. THE GFS SHOWS SIGNIFICANTLY MORE LOW LEVEL MOISTURE IN ITS THERMODYNAMIC PROFILE THAN THE NAM. THE GFS ALSO CUTS OFF THE MOISTURE AT THE -5C LEVEL WHILE THE NAM ENDS AT THE 0C MARK. THEREFORE...BELIEVE ANY PRECIP THAT DOES FALL WILL BE OF THE LIQUID VARIETY. WITH THIS MOISTURE DIFFERENCE...HAVE TAKEN A BLEND OF THE TWO MODELS AND LEFT A 30 POP ALONG AND SOUTH OF M-55. FRIDAY...THE COLD FRONT WILL CONTINUE TO MAKE ITS WAY SOUTHWARD TOMORROW...BUT WILL NOT CLEAR THE CWA UNTIL THE 18Z-21Z TIMEFRAME. MUCH OF THE MID-LEVEL MOISTURE WILL HAVE PUSHED TO THE SOUTH BY 18Z...BUT NAM/GFS BOTH INDICATED A SHARP CUTOFF BETWEEN THE RELATIVELY DEEPER MOISTURE JUST TO THE SOUTH OF THE CWA. BECAUSE OF THIS SHARP MOISTURE CONTRAST...HAVE KEPT A CHANCE FOR RAIN SHOWERS (MOISTURE WILL STRUGGLE TO REACH -10C) ALONG AND SOUTH OF M-55. TEMPERATURES BEHIND THE FRONT WILL BE SIGNIFICANTLY COOLER...AS 850MB TEMPS WILL FALL TO -10C BY 00Z (AND 18Z ACROSS EASTERN UPPER). THIS WOULD PUT DELTA T'S APPROX -10 TO -12C ACROSS LAKE SUPERIOR...SLIGHTLY TOO WARM FOR LAKE EFFECT SNOW DEVELOPMENT. NORTHERLY WINDS BEHIND THE FRONT WILL BE GUSTY TOMORROW WITH A SHARP PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE NW AND LOW PRESSURE TO THE SE. NAM AND GFS SOUNDINGS SHOW WINDS APPROACHING 35 AND 25 KTS RESPECTIVELY WITHIN THE MIXED LAYER ACROSS NW LOWER BY THE AFTERNOON. THESE CONDITIONS WOULD WARRANT AT LEAST A SMALL CRAFT ADVISORY ALONG N-S ORIENTED LAKE MICHIGAN AND LAKE HURON SHORELINES. MPC .LONG TERM...MODELS ARE IN GOOD AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK WITH THE UPPER LEVEL PATTERN REMAINING HIGHLY AMPLIFIED. UPPER LEVEL TROUGH WILL CROSS THE REGION FRIDAY AND FRIDAY NIGHT WITH HIGH PRESSURE AND AN UPPER LEVEL RIDGE BUILDING IN BEHIND THE TROUGH. MODELS DIFFER SLIGHTLY ON AMPLIFICATION OF UPPER LEVEL RIDGE AT THE BEGINNING OF NEXT WEEK WHICH WILL RESULT IN A BIT OF UNCERTAINTY IN THE CLOUDS AND TEMPERATURES. MAIN CONCERNS IN THE LONG TERM CENTER ON CLOUDS/CHANCES OF PRECIPITATION ACROSS EASTERN UPPER FRIDAY NIGHT/SATURDAY MORNING AND RAIN SHOWERS/THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. FRIDAY NIGHT...LOW PRESSURE WILL CONTINUE TO DROP INTO THE MID MISSISSIPPI VALLEY WITH THE UPPER LEVEL TROUGH CROSSING MICHIGAN BEFORE MIDNIGHT. WRAP AROUND MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW IN WESTERN QUEBEC WILL BRUSH THE NORTHER REACHES OF THE CWA WITH 850 MB TEMPERATURES BEING THE BIGGEST CONCERN. BY 06Z 850 MB TEMPERATURES WILL HAVE DECREASED TO -10C TO -12C CREATING LAKE TO 850 MB DELTA T/S IN THE 13C TO 15C RANGE. ALTHOUGH MODEL SOUNDINGS INDICATE THERE WILL BE PLENTY OF DRY AIR AOB 900 MB WILL LIMIT THE LAKE EFFECT POTENTIAL. NORTHERLY WINDS WILL ALSO LIMIT THE POTENTIAL...HOWEVER MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW WILL DROP A BIT FURTHER SOUTH DURING THE NIGHT RESULTING IN A BIT BETTER LAKE EFFECT POTENTIAL. WITH THAT BEING SAID WILL CUT BACK FROM SNOW SHOWERS TO FLURRIES ACROSS THE NW AND NNW LAKE EFFECT PRONE AREAS OF EASTERN UPPER AND NORTHERN LOWER. SATURDAY AND SATURDAY NIGHT...THE UPPER LEVEL TROUGH SWINGS EAST OF THE REGION SATURDAY MORNING WITH SOME WRAP AROUND MOISTURE BEHIND THE UPPER LEVEL LOW PREPARING TO ENTER THE REGION. 850 MB TEMPERATURES WILL BE IN THE -8C RANGE WITH LAKE TO 850 MB DELTA T/S AROUND 11C. THIS BRINGS UP THE POTENTIAL FOR LAKE EFFECT CLOUDS AND SNOW DURING THE MORNING HOURS. THERE ARE SEVERAL FACTORS WHICH WILL LIMIT THE POTENTIAL FOR LAKE EFFECT...STARTING WITH THE DRY AIR INTRUDING AOB 850 MB. 850-700 MB LAYER RH WILL BE 50-60 PCT WHILE 700-500 MB LAYER RH WILL ONLY BE 30 PCT OR LESS. WITH THE AVAILABLE MOISTURE AOB 700 MB LAKE EFFECT WILL BE KEPT TO A MINIMUM AS DENDRITIC GROWTH AND SEEDING PROCESSES WILL BE UNABLE TO TAP INTO AIR COLDER THAN -10C. WITH THAT IN MIND HAVE SCALED BACK THE SNOW SHOWERS TO FLURRIES AND LIMITED THE AREAS TO THOSE FAVORED IN NW AND NNW FLOW. SATURDAY AFTERNOON THROUGH SATURDAY NIGHT WEAK WAA OVERSPREADS THE REGION AND RAISES THE 850 MB TEMPERATURE TO AROUND -4C BY 00Z. WITH THE 850 MB TEMPERATURE INCREASING THE LAKE TO 850 MB DELTA T WILL BE UNDER 10C AND ELIMINATE THE POSSIBILITY OF LAKE EFFECT SNOW. SUNDAY AND SUNDAY NIGHT...HIGH PRESSURE AND A RELATIVELY FLAT UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE AREA WITH THE MAIN MOISTURE AXIS ACROSS SOUTHERN ONTARIO. WEAK WAA WILL STRENGTHEN INTO SUNDAY NIGHT WITH 850 MB TEMPERATURES CLIMBING TO 4C TOWARD DAYBREAK MONDAY. WITH THE HIGH PRESSURE...UPPER LEVEL RIDGE AND CLIMBING 850 MB TEMPERATURES WILL EXPECT NO PRECIPITATION WITH THE GREATEST AMOUNT OF CLOUDS OVER EASTERN UPPER DUE TO THE MOISTURE AXIS. MONDAY AND THE REMAINDER OF THE EXTENDED...AXIS OF UPPER LEVEL RIDGE WILL PUSH INTO THE WESTERN GREAT LAKES WITH HIGH TEMPERATURES SLIGHTLY ABOVE NORMAL. BEGINNING OF THE WEEK WILL REMAIN TRANQUIL AS HIGH PRESSURE WILL KEEP THE MAIN BULK OF THE MOISTURE NORTH OF THE AREA UNTIL THE MIDDLE OF THE WEEK. TUESDAY EVENING THE NEXT LOW PRESSURE WILL ENTER THE REGION BRINGING ANOTHER ROUND OF RAIN SHOWERS. THUNDERSTORMS WILL REMAIN A POSSIBILITY...BUT WITH MODEL SOUNDINGS INDICATING A LACK OF INSTABILITY WILL REMAIN WITH THE RAIN SHOWERS ATTM. LOW PRESSURE CONTINUES TO PUSH ACROSS THE REGION THROUGH THURSDAY MORNING WHEN HIGH PRESSURE AND A MINOR UPPER LEVEL RIDGE ONCE AGAIN ENTER THE AREA. && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 411 PM EDT THU APR 6 2006 .DISCUSSION... WATER VAPOR AND RUC ANALYSIS SHOW RIDGING FROM THE MIDDLE MISSISSIPPI VALLEY NORTHWEST INTO SOUTH CENTRAL CANADA. THE NORTHERN EXTENT OF THIS RIDGING IS UNDER A SQUEEZE PLAY BETWEEN AN AMPLIFIED TROUGH ENTERING THE CENTRAL CONUS FROM THE INTERMOUNTAIN WEST AND POTENT NORTHERN STREAM UPPER LOW DROPPING SOUTH FROM HUDSON BAY INTO NORTHERN ONTARIO. THROUGH TONIGHT...LOOK FOR THE CENTRAL CONUS TROUGH TO BREAK DOWN THE RIDGE TO THE EAST AS IT IS FORCED EAST AND SOUTHEAST BY THE NORTHERN STREAM TROUGH DIGGING INTO THE EASTERN GREAT LAKES AND NORTHEAST CONUS. FURTHER UPSTREAM...NORTH PACIFIC ENERGY IS FORECAST TO REACH THE WEST COAST FRIDAY NIGHT. THIS SYSTEM WILL IMPACT THE GREAT LAKES REGION BY EARLY TO MIDDLE OF NEXT WEEK. 12Z GUIDANCE IS A BIT SLOWER ON THE TROUGH PASSAGE AND RESULTANT CAA INTO THE FORECAST AREA TONIGHT. REALLY A TOUGH DECISION BUT DECIDED TO RAISE MIN TEMPERATURES BY A FEW DEGREES INTO THE UPPER 20S AND LOWER 30S AS SKYCOVER LOOKS TO BE PREDOMINANTLY MOSTLY CLOUDY AND REAL GOOD PUSH OF CAA HOLDS OFF TILL VERY LATE AND ESPECIALLY DURING FRIDAY MORNING. NAM AND GFS (SOMEWHAT) SHOWING A POSSIBLE BREAK IN THE MOSTLY CLOUDY SKIES FOR A WHILE TONIGHT BEHIND THE FRONT AND BEFORE LAKE CLOUDS BEGIN TO FILL IN. WHEN WITH THIS IN THE SKY COVER GRIDS AND ALLOWS FOR PARTLY CLOUDY SKIES TO DEVELOP FOR A WHILE IN MOST AREAS. CONTINUED GOING FORECAST IDEA OF KEEPING ALL QPF OFF TO THE SOUTH OF THE CWA FOR TONIGHT. WEAK ISENTROPIC LIFT AND Q DEEP LAYER Q VECTOR CONVERGENCE ALL SUPPRESSED SOUTH INTO CENTRAL AND SOUTHERN WI. REMOTE CHANCE OF A SPRINKLE OR SHOWER CLIPPING SOUTHCENTRAL CWA...BUT THINK CHANCES ARE REMOTE ENOUGH NOT TO INCLUDE IN FORECAST PACKAGE. NAM AND GFS BUFKIT SHOWING AFTER MIDNIGHT THE POTENTIAL FOR A BIT OF FREEZING DRIZZLE IN THE UPSLOPE FAVORED HIGHER TERRAIN OF NORTHCENTRAL UPPER MI. INVERSION AROUND 3.5K FT WITH INVERSION BASE TEMPS AROUND -9 OR -10 AFTER MIDNIGHT. IF NAM MOISTURE PROFILE IS CORRECT THEN COULD SEE THIS PATCHY FREEZING DRIZZLE IN SPOTS...NOT EXPECTING A MAJOR PROBLEM...BUT THOUGHT IT WORTHY OF ADDING TO THE GRIDS. LATE TONIGHT AND EARLY FRIDAY TEMPS GET BORDERLINE TO CHANGE THINGS OVER THE FLURRIES...BUT EITHER WAY SHOULD BE MINOR AND DIMINISH BY EARLY AFTERNOON WITH AFTERNOON DIURNAL DISRUPTION. FLURRIES OR NOT...FRIDAY LOOKS TO BE A BREEZY BLUSTERY DAY ACROSS THE AREA. DID BUMP TEMPS BACK UP A FEW DEGREES AS NOT CONVINCED ON MOSTLY CLOUDY SKIES ALL DAY. IN FACT...AWAY FROM LAKE SUPERIOR COULD SEE SOME PARTLY SUNNY SKIES AT TIMES...AND THIS TIME OF YEAR IT IS HARD TO KEEP THINGS IN THE LOWER 30S WITH SUN. UPSLOPE AREAS OF THE NORTHCENTRAL U.P WILL BE COOLEST WITH LOWER TO MIDDLE 30S A GOOD BET. LIKELY TO SEE SOME FLURRIES REDEVELOP OFF LAKE SUPERIOR INTO THE EASTERN CWA DURING FRIDAY NIGHT AND CONTINUE INTO SATURDAY MORNING...AGAIN NOT EXPECTING MUCH OF ANYTHING FROM THESE SNOW SHOWERS. WITH DIURNAL DISRUPTION AND RIDGE BUILDING INTO AREA ANY FLURRIES SHOULD END BY MIDDAY. EXPECTING AT LEAST PARTLY SUNNY SKIES BY AFTERNOON. BUMPED TEMPS UP AGAIN HERE...FULL MIXING WOULD YIELD MIDDLE TO UPPER 40S WEST AND LOWER TO MIDDLE 40 EAST...BUT THOUGH SOME CLOUDS IN THE MORNING MAY HAMPER FULL MIXING AND WENT WITH LOWER TO MIDDLE 40S ALL AREAS. RIDGE OVERHEAD SATURDAY NIGHT AND THINKING THE POTENTIAL FOR A FAIRLY COLD NIGHT LOOK GOOD. RADIATIONAL COOLING MAY BE NEAR IDEAL...ESPECIALLY IN FIRST HALF OF THE NIGHT AND ALLOWED THE NORMAL COOLER SPOTS TO FALL INTO THE MIDDLE AND UPPER TEENS. STILL DRY FOR SUNDAY WITH RIDGE IN CONTROL...BECOMING WARMER WITH 850 MB TEMPS WARMING TO AROUND 0 BY EVENING. MIXING TO 850MB DURING THE DAY GIVES LOWER TO MIDDLE 50S AND THINK THIS IS A GOOD BET. SOUTH TO SOUTHEASTERLY DOWNSLOPE FAVORED AREAS LIKE IRONWOOD COULD SEE UPPER 50S TO NEAR 60 BY LATE AFTERNOON. MODELS ARE A BIT BETTER ORGANIZED IN THERE SOLUTIONS FOR THE SYSTEM TO IMPACT THE GREAT LAKE EARLY TO MIDDLE OF NEXT WEEK...BUT THEY ARE STILL NOT COMPLETELY AGREED. GENERALLY RAN WITH A BLEND OF THE ECMWF AND CANADIAN FOR THIS EXTENDED PACKAGE. THE FEEL THE GFS HAS THE RIGHT IDEAS BUT ITS TIMEFRAME IS A BIT TO FAST. LEFT MONDAY DRY AT THIS POINT...THE GFS HAS A WEAK SHORTWAVE RUNNING ALONG THE U.S./CANADIAN BORDER SUNDAY NIGHT AND EARLY MONDAY WITH WEAK 290 TO 295K ISENTROPIC LIFT PRODUCING SOME LIGHT QPF. OTHER GUIDANCE PACKAGES KEEP THIS PIECE OF ENERGY FURTHER TO THE WEST. 850MB THETA E RIDGE ADVANCING ACROSS THE PLAINS AHEAD OF LOW PRESSURE DEVELOPING IN EASTERN COLORADO WILL BEGIN TO SPREAD CLOUDS ACROSS THE WEST HALF OF THE FORECAST AREA BY MONDAY AFTERNOON. HOW FAST THE HIGH CLOUDS COME IN WILL BE IMPORTANT. INDICATIONS ARE THAT IF ENOUGH SUN IS PRESENT MONDAY THAT TEMPERATURES COULD GET QUITE WARM. 850MB TEMPS RISE TO BETWEEN +5 AND +6C DURING THE DAY...PER ECMWF AND GFS. RAISED TEMPS TO THE MIDDLE AND UPPER 50S...HOWEVER...WITH ENOUGH SUN WOULD NOT BE SURPRISED TO SEE A FEW LOWER 60S ALONG WISCONSIN BORDER AND IN AREAS FAVORED BY SOUTHERLY TO SOUTHEASTERLY DOWNSLOPING. RAISED MIN AS WELL FOR MONDAY NIGHT AS SOUTHERLY GRADIENT CONTINUES TO DEVELOP AND CLOUDCOVER BECOMES MORE ESTABLISHED...ESPECIALLY ACROSS THE WEST. THERE IS SOME POTENTIAL FOR THINGS TO COOL OFF A BIT MORE ACROSS THE EAST DURING THE EVENING AS THIS AREA SHOULD SEE LIGHTER WINDS BEING CLOSER TO THE RIDGE AXIS TO THE EAST...HOWEVER EVEN HERE LOOKING FOR TEMPS TO STEADY OFF OR EVEN RISE AFTER MIDNIGHT. CENTRAL PLAINS SYSTEM BEGINS TO LIFT OUT TOWARD THE UPPER MISSISSIPPI VALLEY LATE TUESDAY AND TUESDAY NIGHT. PROGRESSED THE CHANCE FOR SHOWERS EASTWARD ACROSS THE WESTERN AND CENTRAL PORTIONS OF FORECAST AREA DURING THE DAY. 300K TO 305K ISENTROPIC LIFT IS MAXIMIZED JUST TO THE WEST OF THE FORECAST AREA BUT CLOSE ENOUGH THAT ANY PRECIP PRODUCED WOULD RAPIDLY SPREAD EAST INTO THE WESTERN ZONES. ADDED THE CHANCE FOR ISOLATED THUNDER AS SHOWALTER INDICES FALL TO BELOW 0 FOR A TIME ACROSS THE WEST...ESPECIALLY TUESDAY MORNING AND EARLY AFTERNOON. ALTHOUGH THERE IS STILL SOME UNCERTAINTY IN THE TIMING OF PRECIP DURING TUESDAY...DID BUMP UP HIGH TEMPERATURES A BIT...POTENTIAL FOR ANOTHER WARM DAY EXISTS...IF THICKEST CLOUDS / PRECIP DO NOT COME IN AS QUICKLY. ALTHOUGH KEPT THINGS DRY ACROSS THE EAST...SOUTHERLY FLOW OFF LAKE MICHIGAN SHOULD KEEP TEMPERATURES IN CHECK...IN FACT KEPT THINGS IN THE UPPER 40S CLOSE TO THE LAKE WITH ONLY LOWER 50S WELL INLAND...AND UP TOWARD LAKE SUPERIOR. SPREAD THE CHANCE OF SHOWERS ACROSS THE ENTIRE FORECAST AREA FOR TUESDAY NIGHT AND WEDNESDAY. DID NOT INCLUDE THE THREAT FOR THUNDER AS THE BEST INSTABILITY (SHOWALTER +1 OR LESS) IS SUPPRESSED SOUTH INTO CENTRAL WI AND MUCH OF LOWER MI. DESPITE THIS...WOULD NOT BE SURPRISED TO SEE SOME THUNDER ACROSS THE FAR SOUTHERN ZONES. LATER SHIFTS WILL HAVE TO RE-EVALUATE. SHOWERS END ACROSS THE AREA ON WEDNESDAY NIGHT...DID LEAVE THE CHANCE FOR A FEW ISOLATED SHOWERS OR SPRINKLES ACROSS THE FAR EAST DURING THURSDAY MORNING BUT IN GENERAL SHOULD SEE DRYING CONDITIONS AND DECREASING CLOUDS AS HEIGHTS BUILD BEHIND DEPARTING SYSTEM. WENT CLOSE TO GUIDANCE ON TEMPERATURES FOR WEDNESDAY NIGHT AND THURSDAY AS COLD AIR LOOKS TO BE LOCKED TO OUR NORTH WITH NO SIGNIFICANT CAA INTO THE UPPER GREAT LAKES. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ MROCZKA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 320 PM EDT THU APR 6 2006 .SHORT TERM... THE FIRST ISSUE IS JUST HOW FAST CAN THE MOISTURE ADVECTION FROM THE SOUTH OVERCOME ALL THOSE LOW SURFACE DEW POINTS AND SHALLOW DRY AIR. THE SECOND ISSUE IS JUST HOW WET WILL THIS SYSTEM BE FOR SOUTHWEST MICHIGAN? THE RUC AND SPC ENSEMBLES ARE MUCH WETTER THAN ARE THE NAM AND GFS...LIKE NEARLY TWICE THE QPF AND FARTHER NORTH TOO. FINALLY THERE IS THE ISSUE OF WILL THERE REALLY BE SNOW HERE TOMORROW AFTERNOON? THE ISSUE FOR THUNDERSTORMS IS NEARLY GONE...THOSE WILL REALLY BE SOUTH OF INTERSTATE 94. SKIES WILL CLEAR QUICKLY FRIDAY EVENING AND FEW CLOUDS ARE EXPECTED SATURDAY AND SATURDAY NIGHT BUT IT WILL BE RATHER CHILLY TO SAY THE LEAST. TONIGHT...18Z TAMDAR FROM DTW SHOWED 40F BTW THE TEMP AND DEW POINT AT 900 MB. ONE HAS TO GET TO NEAR 700 MB TO SEE TEMP DEW POINT DEPRESSIONS LESS THAN 5F. THAT IS A LOT OF DRY TO MOISTEN. GIVEN MOST OF THE ISENTROPIC LIFT TONIGHT IS SOUTH OF INTERSTATE 94 THANKS TO THE UPSTREAM RIDGE AHEAD OF THE SOUTHERN STREAM WAVE THE MOISTURE WILL BE IN NO HURRY TO MAKE IT INTO SOUTHWEST MICHIGAN. IT WILL TAKE TILL AFTER MIDNIGHT FOR ENOUGH MID LEVEL MOISTURE TO REACH THIS AREA TO THAT THE LOWER LEVELS WILL ALLOW THE RAIN TO REACH THE GROUND. BASED ON THE 850 MB LI... THUNDER IS NEARLY OUT OF THE QUESTION. STILL I LEFT IT IN OVER THE SOUTH... MORE FOR CONTINUITY THAN BECAUSE I BELIEVE IT WILL HAPPEN. FRIDAY...REALLY MOST OF THE PRECIPITATION WILL COME FROM THE STRENGTH OF THE FRONTOGENESIS /FGEN/ NEAR 700 MB OVER CENTRAL AND NORTHERN LOWER MICHIGAN FRIDAY BETWEEN 12Z AND 21Z. SEEMS TO ME THE NRN STREAM SYSTEM WILL LARGELY CUT OFF THE INFLOW FROM THE SOUTHERN STREAM SYSTEM FRIDAY. THE UPSTREAM RIDGE AXIS FROM THE SOUTHERN STREAM SYSTEM IS NOT EVEN EAST OF OUR CWA EVEN AT 12Z FRIDAY MORNING. THE FGEN FOR FRIDAY IS IMPRESSIVE AND IT THAT WHICH WILL FORCE ALMOST ALL OF OUR QPF FROM THIS EVENT. PROBLEM IS THE SPC ENSEMBLES PAGE HAS BEEN INDICATING 1 1/2 TO 2 INCHES OF RAIN BETWEEN ROUTE 10 AND I-96 FOR SEVERAL RUNS NOW. IT'S BEEN VERY CONSISTENT. ALSO THE RUC13 AND RUC20 SHOW SOMETHING RATHER SIMILAR. THE RUC QPF DID BETTER THAN THE NAM OR GFS FOR 00Z TO 12Z TODAY TOO. GIVEN ALL OF THAT...I BELIEVE MOST OF THE HEAVY RAINFALL WILL BE NEAR AND NORTH OF INTERSTATE 96 FRIDAY DURING THE DAY TIME... MOSTLY 15Z TO 21Z. THE AIR DOES NOT GET COLD ENOUGH FOR SNOW TILL AFT 18Z. THAT WILL LIMIT ACCUMULATIONS SOME. SO THE BOTTOM LINE IS RAIN SHOULD REALLY DEVELOP AFTER 03 AM AND BECOME MODERATE TO HEAVY AT TIMES BETWEEN I-94 AND 60 MILES N OF I-96 BY MID MORNING. THE COLD AIR WILL CHANGE THE RAIN TO SNOW FROM SOUTH TO NORTH AFTER 16Z. IN AREAS WERE THE PRECIPITATION NOT ALL THAT HEAVY IN TERMS OF RATE... IT LIKELY WILL STAY A MIX OF RAIN AND SNOW. ONLY IN AREAS WHERE IT IS PRECIPITATING AT MORE THAN A 0.05 INCHES PER HOUR (LIQUID RATE) WILL IT CHANGE TO ALL SNOW. LOCATIONS NEAR I-96 TO 60 MILES OR SO NORTH OF THERE COULD SEE A FEW INCHES ON THE GRASS IF ALL GOES WELL. IF THE FGEN BAND REALLY GETS GOING LIKE THE SPC ENSEMBLES SUGGEST THERE COULD BE 5 TO 7 INCHES BUT FOR NOW THAT IS NOT A HIGH ENOUGH CHANCE EVENT TO DO MORE THAN WRITE A FEW WORDS ABOUT. AFTER THAT...A VERY LARGE CANADIAN HIGH MOVES IN WITH A LOT OF DRY COOL AIR. HIGHS WILL STRUGGLE TO GET ABOVE 45F SATURDAY. SATURDAY NIGHT MAY BE THE COLDEST NIGHT OF THE MONTH WITH MOSTLY CLEAR SKIES AND LIGHT WINDS. .LONG TERM... THE MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT WITH EACH OTHER AND WITH PREVIOUS MODEL RUNS. FOLLOWED THE GFS FOR EASE AND MADE CHANGES TO IMPROVE INTER OFFICE CONSISTENCY. THE EXTENDED FORECAST BEGINS WITH AN AREA OF HIGH PRESSURE OVER THE REGION. DRY WEATHER AND PARTLY CLOUDY SKIES ARE ANTICIPATED THROUGH TUESDAY. TEMPERATURES WILL WARM UP EARLY NEXT WEEK AS THE HIGH PRESSURE RIDGE MOVES TO THE EAST COAST AND A LOW LEVEL SOUTHERLY RETURN FLOW DEVELOPS OVER THE GREAT LAKES. A POTENTIAL WEATHER MAKER WILL MOVE INTO THE PLAINS ON TUESDAY. EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS AHEAD OF THIS SYSTEM TUESDAY NIGHT. LOOKS TO BE A VIGOROUS SYSTEM WITH GOOD MOISTURE... SO HAVE BUMPED UP POPS. HAVE SHOWERS AND THUNDERSTORMS WEDNESDAY AND WEDNESDAY NIGHT WITH A FEW LINGERING RAIN SHOWERS ACROSS THE NORTH THURSDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEK ONCE THE WARMUP OCCURS. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WDM IOD mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1150 AM EDT THU APR 6 2006 .UPDATED... I AM BECOMING INCREASINGLY CONCERNED WITH THE STRENGTH OF THE FRONTOGENESIS /FGEN/ NEAR 700 MB OVER NRN LOWER MICHIGAN FRIDAY. IT SEEMS TO ME THE NRN STREAM SYSTEM WILL LARGELY CUT OFF THE INFLOW FROM THE SOUTHERN STREAM SYSTEM. THE UPSTREAM RIDGE AXIS FROM THE SOUTHERN STREAM SYSTEM IS NOT EVEN EAST OF OUR CWA EVEN AT 12Z FRIDAY MORNING. SO I BELIEVE WE WILL HAVE A HARD TIME GETTING TO MUCH DEEP MOISTURE NORTH INTO MICHIGAN TONIGHT. JUST ABOUT ALL OF THE ISENTROPIC LIFT WITH THE SOUTHERN STREAM SYSTEM STAYS SOUTH OF INTERSTATE 80 TONIGHT INTO FRIDAY. SO IT IS THAT IMPRESSIVE FGEN TOMORROW THAT WILL FORCE ALMOST ALL OF OUR QPF FROM THIS EVENT. PROBLEM IS THE SPC ENSEMBLES PAGE HAS BEEN INDICATING 1 1/2 TO 2 INCHES OF RAIN BETWEEN ROUTE 10 AND I-96 FOR SEVERAL RUNS NOW. IT'S BEEN VERY CONSISTENT. ALSO THE RUC13 AND RUC20 SHOW SOMETHING RATHER SIMILAR. THE RUC QPF DID BETTER THAN THE NAM OR GFS FOR 00Z TO 12Z TODAY TOO. GIVEN ALL OF THAT...I BELIEVE MOST OF THE HEAVY RAINFALL WILL BE NEAR AND NORTH OF INTERSTATE 96 FRIDAY DURING THE DAY TIME... MOSTLY 15Z TO 21Z. THE AIR DOES NOT GET COLD ENOUGH FOR SNOW TILL AFT 18Z. THAT WILL LIMIT ACCUMULATIONS SOME. I WILL LOOK AT THE LATEST GFS BUT AT THIS POINT I PLAN ON PUSHING THE FORECAST IN THE DIRECTION OF MOST OF THE PRECIPITATION TOMORROW WITH THE HEAVIEST QPF OVER THE CENTRAL AND NRN CWA. THE CURRENT ZONES LOOK GOOD TO ME FOR THIS AFTERNOON AND EVENING SO I DO NOT PLAN AN UPDATE. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1120 AM EDT THU APR 6 2005 UPDATE...RUC ANALYSIS AND IR/VIS SAT IMAGERY SHOW SURFACE HIGH PRESSURE AXIS STRETCHED ACROSS THE CWA THIS MORNING...WITH PARTLY SUNNY TO PARTLY CLOUDY SKIES CURRENTLY ACROSS THE AREA. 8K-10KFT CLOUD DECK IS STRETCHING FROM MINNESOTA TO WESTERN LOWER MICHIGAN. TEMPS WERE RISING SLOWER THAN EXPECTED THIS MORNING...MOSTLY IN THE LOWER TO MIDDLE 40S AS OF 10 AM. WITH THE MID-LEVEL CLOUD DECK EXPECTED TO CONTINUE TO PROGRESS EASTWARD AND BECOME THICKER THIS AFTERNOON...AND THE FACT THAT TEMPS HAVE BEEN SLOWER TO WARM THAN ADVERTISED...HAVE NUDGED DOWN HI TEMPS A FEW DEGREES ACROSS THE CWA...BUT STILL TOPPING OUT IN THE MIDDLE TO UPPER 50S ACROSS INLAND AREAS OF NORTHERN LOWER AND NEAR 50 ACROSS INLAND EASTERN UPPER. HAVE ALSO BUMPED UP CLOUD COVER TO MOSTLY CLOUDY FOR THE WESTERN HALF OF NORTHERN LOWER. NO OTHER CHANGES WERE MADE...LAKE BREEZES STILL LOOK TO BE A GOOD BET THIS AFTERNOON. UPDATE ALREADY OUT. MPC && .PREV DISCUSSION ISSUED AT 350 AM EDT THU APR 6 2005 500 MB RIDGE AND SFC RIDGE CONTINUE TO BUILD ACROSS THE REGION THIS MORNING WITH LIGHT WINDS, BUT WITH WAA CLOUDS MOVING OVER THE REGION. TO THE WEST THE NEXT SYSTEM WHICH WILL BE THE MAIN CONCERN FOR THE PACKAGE HAS BEGUN ITS DEVELOPMENT ALONG THE FRONT RANGE OF THE ROCKIES AND IN THE CENTRAL PLAINS. MODELS...ALL 5 MODELS ARE IN PRETTY GOOD AGREEMENT (GFS, NAM/ETA, NAM/WRF, UKMET, ECMWF). LEANED TOWARD THE GFS, THOUGH SINCE IT HAS BEEN THE MOST CONSISTENT. TODAY...HIGH PRESSURE SUNNY SKIES AND LIGHT SOUTH FLOW, NOT TO MENTION THE BUILDING 500 MB HEIGHTS WILL GET TEMPERATURES AWAY FROM THE GREAT LAKES OF AROUND 60, MAYBE EVEN WARMER. NEAR THE LAKES WILL BE A DIFFERENT STORY. WITH THE LIGHT 950 MB FLOW (MAINLY LESS THAN 10 KNOTS ALL DAY), AND THE LAKE-LAND DELTA T OF ABOUT 13C, WOULD EXPECT DEEP PENETRATION OF THE LAKE BREEZE. SO HAVE TRIED TO ADJUST THE TEMPERATURES ALONG THE LAKE ACCORDINGLY, IN A FIRE WEATHER VAIN THE RELATIVE HUMIDITY. ALSO IN A FIRE WEATHER VAIN, WITH THE LIGHT FLOW WOULD EXPECT UP VALLEY AND UPSLOPE WINDS WHERE THERE IS CONSIDERABLE TERRAIN VARIANCE. EXPECTING THE RELATIVE HUMIDITY TO BE AROUND OR LESS THAN 25% IN OUR FAVORED AREAS. TONIGHT...REMOVED THE THREAT OF RAIN IN THE EVENING, AS THE MODELS ARE IN AGREEMENT THAT THE FLOW TURNS NORTHEASTERLY WHICH IS DRY ENOUGH TO KEEP THE PRECIPITATION AT BAY AND HELPS THE BAROCLINIC ZONE SHARPEN UP FURTHER SOUTH THAN DEPICTED YESTERDAY. OVERNIGHT, THE FRONT MOVES NORTH AND AFFECTS AREAS SOUTH OF M-72, THOUGH PRECIPITATION LOOKS TO BE ON THE LIGHT SIDE AGAIN FROM DRY SFC FLOW FROM THE NE. IF THE MODELS ARE RIGHT THE MAIN ACTION WILL BE IN N INDIANA ALONG THE SFC TROUGH/WARM FRONT, THIS SHOULD KEEP THE PRECIPITATION AT BAY. WOULD NOT BE SURPRISED IF THE NAM/ETA WITH NO PRECIPITATION WOULD BE RIGHT, BUT WITH THE GFS BEING FAIRLY CONSISTENT, WILL KEEP POPS IN THE SOUTH. TEMPERATURE PROFILES WILL BE RAIN BETWEEN 06Z AND 09Z, THEN IT WILL APPROACH FREEZING ENOUGH THAT THERE WILL BE SOME MIXING OF PRECIPITATION TYPES. FRIDAY...THE MORNING WILL HAVE PRECIPITATION MAINLY ALONG AND SOUTH OF M-55 AND WILL HAVE CHANGED TO ALL SNOW AS THE COLD AIR FORCES THE WARM FRONT SOUTH AND THE SFC TROUGH GETS FAR ENOUGH EAST TO REINFORCE THE NORTHEAST FLOW. SO THE FOR AFTERNOON, WOULD EXPECT THAT THE PRECIPITATION WILL CEASE FOR A FEW HOURS AS THE MOISTURE ID LOW (RH<40% IN 850 AND 700-500 MB). 850 TEMPERATURES DON'T BEGIN TO GET COLD ENOUGH UNTIL FRIDAY EVENING (<-10C). LUTZ LATER PERIODS...ANOTHER SHOT OF COOL AIR TO START THE WEEKEND...AS UPPER TROF AXIS PIVOTS THRU. UNLIKE THIS LAST ONE THOUGH...THE AIRMASS IS PRETTY DRY. THUS MAIN CONCERN FOR FRIDAY NIGHT/SATURDAY IS CLOUDS...AND WHETHER ANY LIGHT LAKE EFFECT SNOW CAN FORM. FRIDAY NIGHT...INITIAL 850MB THERMAL TROF WILL DROP ACROSS THE FORECAST AREA DURING THE EVENING/EARLY OVERNIGHT HOURS. 850MB TEMPS DROP AS LOW AS -10C ON LAKE MI...-13C ON HURON...AND -12C ON SUPERIOR (EARLY). 1000-850MB FLOW IS BASICALLY NORTH THRU THE NIGHT...BACKING NNW LATE AHEAD OF A SHORTWAVE HEADING DUE SOUTH FROM NORTHERN ONTARIO. AIRMASS IS PRETTY DRY THRU MOST OF THE NIGHT... WITH 850-700MB RH LEVELS BELOW 20 PERCENT ON LAKE MI...25-30 PERCENT ON HURON/SUPERIOR. NOT SURPRISINGLY...INVERSION HEIGHTS ARE QUITE LOW...AROUND 3K FEET/900MB. HOWEVER...WE WILL SEE A MOISTURE INCREASE IN THE NORTH LATE THANKS TO THAT SHORTWAVE. BY 09Z...850- 700MB RH LEVELS ARE RAMPING UP TO BETTER THAN 70 PERCENT OVER CENTRAL AND NORTHERN SUPERIOR. THE DRY AIRMASS AND LARGELY UNFAVORABLE FETCH LEADS TO GO WITH JUST FLURRIES IN NORTH FLOW SNOWBELTS IN THE EVENING...RAMPING UP TO A SMALL CHANCE OF SNOW SHOWERS OVERNIGHT...WITH THE HIGHEST POPS IN WESTERN CHIPPEWA. FAR EASTERN UPPER MI...AND NORTH CENTRAL LOWER...WILL LIKELY STAY RELATIVELY CLOUD FREE GIVEN THE NORTH FETCH...WITH CHILLY MIN TEMPS IN THE LOW/MID TEENS. CLOSER TO 20/LOWER 20S NEAR THE BEACHES. SATURDAY...ARRIVAL OF BETTER MOISTURE AND A SECONDARY 850MB THERMAL TROF (850MB TEMPS AROUND -9C) WILL KEEP SCT SNOW SHOWERS GOING IN THE NW FLOW SNOWBELTS THRU THE MORNING AND INTO EARLY AFTERNOON. 850MB TEMPS WILL RAPIDLY REBOUND IN THE PM HOURS THOUGH...NEARING -5C OVER THE UPSTREAM LAKES BY 00Z...THUS SNOW SHOWERS SHOULD CUT OFF LATER IN THE DAY. WARMING MAY BE TOO LATE TO HELP MAX TEMPS MUCH...WILL COMPROMISE BETWEEN WARMER MAV AND COOLER MET NUMBERS. SO MAX TEMPS GENERALLY AROUND 40F. NO CHANGES TO LATER PERIODS. MODELS CONTINUE TO FAVOR A DRY PATTERN INTO THE LATTER PART OF THE WEEKEND....AS BROAD UPPER RIDGING GETS ESTABLISHED MID-CONUS. GFS BRINGS A SHOT OF MOISTURE INTO EASTERN UPPER SUNDAY NIGHT AS STRONGER WARM ADVECTION BEGINS. THE BULK OF THIS AFFECTS SUPERIOR AND NORTHWARD THOUGH AND WILL KEEP THINGS DRY FOR NOW. ZOLTOWSKI && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1000 AM EDT THU APR 6 2006 .UPDATE... PRIMARY CHANGE WAS TO INCREASE SKY COVER THROUGH MAJORITY OF AFTN AS SWATH OF MID LEVEL MOISUTURE (100MB THICK PER GRB 12Z SOUNDING) SLIDES ACROSS REGION. 300K SFC ON RUC/GFS INDICATE BY LATE AFTN DRY AIR OVR N MN WILL WORK INTO LK SUPERIOR HELPING TO DEVELOP SOME BREAKS OF SUNSHINE IN THE CLOUD DECK. EVEN WITH THICK MID CLOUDS OVERHEAD...LOW LEVEL TEMPS ARE QUITE WARM (H9 TEMP OF +7C AT GRB) SO EVEN LIMITED MIXING SUPPORTS GOING FCST HIGHS UPR 40S INTO LWR 50S. WINDS BECOME NE/N LATE OVR FAR W CWA AS HIGH OVR CNTRL CANADA BEGINS TO BUILD INTO THE REGION. FOR FAR W AREAS...TEMPS MAY TRY TO COOL SLIGHTLY AS WINDS BECOME ONSHORE LATE TODAY. && .PREV DISCUSSION (ISSUED AT 400 AM EDT)... THE UPPER LOW OVER JAMES BAY WILL SHIFT TO THE SOUTHERN TIP OF JAMES BAY ON TONIGHT. SHORTWAVE ENERGY WRAPPING AROUND THIS LOW WILL SWEEP INTO CENTRAL ONTARIO. 850MB-500MB Q-VECTOR CONVERGENCE WILL SHIFT ACROSS EASTERN ONTARIO. THE ENERGY WILL STAY NORTH OF THE FORECAST AREA. THE NEBRASKA LOW WILL REMAIN NEARLY STATION...HOWEVER...THE LOW WILL BECOME STRETCH OUT FROM NEBRASKA INTO NORTHERN NEW ENGLAND. THE CANADIAN HIGH WILL PUSH INTO SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AHEAD OF THE CANADIAN RIDGE WILL BRING MORE DRY AIR INTO THE FORECAST AREA. AN 850MB THERMAL TROUGH WILL SHIFT ACROSS ONTARIO INTO LAKE SUPERIOR. DELTA-T'S ACROSS THE NORTHERN LAKE SUPERIOR WILL INCREASE TO 15C. THE NORTH WIND IN CONJUNCTION WITH THE HIGH DELTA-T'S COULD PRODUCE LAKE EFFECT SNOWS. THE AIR MASS WILL REMAIN FAIRLY DRY WHICH SHOULD LIMIT SNOW PRODUCTION MAINLY ALONG THE LAKE SUPERIOR SNOW. THE CANADIAN MID LEVEL LOW WILL SWING INTO SOUTHERN QUEBEC...WHILE PUSHING A SHORTWAVE THROUGH THE FORECAST AREA FRIDAY. THE SHORTWAVE WILL MERGE WITH THE SOUTHERN SYSTEM WHICH WILL SLIP INTO OKLAHOMA. THE CANADIAN HIGH WILL SETTLE INTO SOUTHERN MANITOBA BLANKETING MUCH OF THE NORTHERN PLAINS. THE HIGH PUSH THE COLD FRONT THROUGH THE OHIO RIVER VALLEY AND THE LOWER GREAT LAKES. ANTI-CYCLONIC FLOW WILL KEEP THE WINDS OUT OF THE NORTHEAST. DRY AIR OVER THE AREA WILL LIMIT SNOW SHOWERS. THE 850MB DELTA-T'S WILL AROUND 13C. THE CANADIAN LOW WILL SWEEP INTO SOUTHERN QUEBEC...WHILE BRINGING WEAK SHORTWAVES THROUGH UPPER MICHIGAN AND LAKE SUPERIOR FRIDAY NIGHT. THE CANADIAN SURFACE RIDGE WILL MOVE INTO THE UPPER GREAT LAKES AND CONTINUE TO DRAW DRY AIR INTO THE REGION. THE DELTA-T'S OVER EASTERN LAKE SUPERIOR WILL DIMINISH TO 11C OVERNIGHT. THE POSSIBILITY OF WEAK LAKE EFFECT SNOW WILL CONTINUE NEAR THE LAKE SHORE OF THE EASTERN U.P. THUS WILL KEEP A MENTION OF GREAT LAKES HAVING LAKE EFFECT SNOWS. AS THE NIGHT PROGRESSES SHOWERS WILL DIMINISH. DRY AIR WILL BE THE LIMITING FACTOR. THE RIDGE WILL CONTINUE TO KEEP DRY AIR STABLE AIR THE FORECAST AREA THROUGH SUNDAY. ON SUNDAY AS THE SURFACE LOW SHIFT INTO THE OHIO RIVER VALLEY WINDS WILL GRADUALLY VEER TO THE SOUTH. THEN WARM MOISTURE AIR WILL ONCE AGAIN INVADE THE UPPER GREAT LAKES THROUGH TUESDAY. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JLA PREV DISCUSSION...DLG mi AREA FORECAST DISCUSSION...UPDATED MESOSCALE AND AVN DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 1008 PM CDT THU APR 6 2006 ...TORNADO WATCH 159 IN EFFECT THROUGH 1 AM FRIDAY MORNING... .MESOSCALE DISCUSSION... A DRY LINE ASSOCIATED WITH A LOW PRESSURE SYSTEM IN SOUTHWESTERN IOWA EXTENDS SOUTH ACROSS CENTRAL MISSOURI. THUNDERSTORM CELLS ARE FORMING ALONG THIS LINE AS THE LINE CONTINUES TO MOVE EAST THROUGH THE EVENING. PRESENTLY...THE THUNDERSTORMS APPEAR TO BE WEAKENING. BUT RUC SOUNDINGS JUST AHEAD OF THAT DRY LINE SHOWING CAPES UP NEAR 2600 J/KG AND THE LINE IS STILL MOVING INTO AN AREA OF DEWPOINTS NEAR 60 DEGREES. AIRMASS MAY HAVE BEEN WORKED OVER WITH EARLIER PRECIPITATION...BUT WILL HAVE TO STRAY ON THE SAFE SIDE FOR ANOTHER FEW HOURS TO SEE IF THE LINE REGENERATES ANYTHING. CLEARED WESTERN ZONES OF THE TORNADO WATCH AS DEWPOINTS BEHIND THE DRYLINE IN THE MID TWENTIES STARTING TO MAKE THEIR WAY INTO EXTREME SOUTHEAST KANSAS AND SHOULD START MAKING IT INTO SOUTHWESTERN MISSOURI AS WELL. GCC && .AVIATION UPDATE... LINE OF THUNDERSTORMS CURRENTLY MOVING NORTHEASTWARD OUT AHEAD OF THE ADVANCING DRYLINE. STORMS WILL BE AFFECTING THE KJLN TERMINAL THROUGH 03Z AND THE KSGF TERMINAL THROUGH 04Z. ONCE INITIAL LINE PASSES...EXPECT WINDS TO SHIFT AROUND TO SOUTHWEST BUT STILL REMAIN GUSTY THROUGH THE OVERNIGHT HOURS. GAEDE && .PREV DISCUSSION...302 PM SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT): COMPLEX WEATHER PATTERN EVOLVING OVER THE CENTRAL U.S. AT THIS TIME. CURRENT WAT VAP IMAGERY/RUC INITIALIZATION OF 500MB VORTICITY INDICATES THAT THE LEAD SHORT WAVE DISTURBANCE IS LIFTING THROUGH THE AREA. REGIONAL WSR 88D SHOWS THE ASSOCIATE COMPLEX OF SHRA/TSRA QUICKLY MOVING TO THE NORTHEAST THROUGH THE MO OZARKS. MEANWHILE... A VERY POTENT UPPER DISTURBANCE IS EMERGING INTO THE CENTRAL PLAINS. AT THE SFC...THE DRYLINE HAS SET UP OVER CENTRAL KS/OK AND PER LATEST VIS SAT IMAGERY...A CU FIELD IS DEVELOPING ALONG/AHEAD THIS FEATURE. INSOFAR AS MOISTURE IS CONCERNED...THE TODAY'S RAINFALL HAS MAINTAINED DECENT BL MOISTURE WITH UPPER 50S TO LOWER 60S SFC DEWPOINTS ACROSS THE REGION. JUST TO THE WEST...WHERE PARTIAL CLEARING HAS OCCURRED AHEAD OF THE DRYLINE...DEWPOINTS ARE IN THE LOW/MID 60S. THE LATEST RUC/NAM/GFS INDICATE THAT LOWER 60S WILL CONTINUE TO SPREAD INTO THE REGION THIS AFTERNOON. HEATING AND INSTABILITY HAVE BEEN LIMITED THUS FAR TODAY. OUR RAINFALL HAS SUCCESSFULLY HELD TEMPS IN THE MID 60S TO LOWER 70S...HOWEVER...OVER THE NEXT TWO HOURS THE COMPLEX OF SHRA/TSRA WILL EJECT TO THE EAST/NORTHEAST INTO E MO WILL SET UP A BRIEF BREAK IN THE ACTIVITY ACROSS THE REGION. SOME PARTIAL CLEARING IS EXPECTED DURING THE LATE AFTERNOON HOURS...PARTICULARLY OVER THE WESTERN SECTIONS OF THE CWFA WHICH WILL ALLOW FOR WARMING INTO THE MID TO UPPER 70S. EASTERN PORTIONS OF THE CWFA WILL HAVE LITTLE TIME TO WARM UP AFTER RAINFALL EXITS AND MAY MAKE IT BACK TO AROUND 70. ACCORDING TO SGF 15Z AND 18Z RAOBS...A RATHER STOUT CAP HAS BEEN WEAKENED A BIT. AFTER LOOKING AT THE 18Z RAOBS FROM TOP AND OUN (ALONG WITH A 45-50 KT LLJ SURGING INTO THE REGION) I EXPECT A BRIEF REINVIGORATION OF THE CAP. INSTABILITY THUS FAR HAS BEEN A FEW HUNDRED J/KG AND RATHER ELEVATED IN NATURE (ABOVE 700MB)...HOWEVER AS THE UPPER DISTURBANCE PIVOTS TO THE EAST...LAPSE RATES WILL STEEPEN AND MLCAPES WILL RISE TO BETWEEN 1000 AND 1500 J/KG. TREMENDOUS WIND ENERGY IS ASSOCIATED WITH THIS SYSTEM...A 110KT ULJ...A 90KT MID LEVEL JET...AND A 45KT LLJ. AS A RESULT...SHEAR IS HIGH. 0-6KM BULK SHEAR IS AROUND 75KTS...WITH 0-1KM SHEAR 20-30KTS. AS THE UPPER DISTURBANCE MOVES NORTHEAST THIS AFTERNOON AND EVENING...THESE SHEAR VALUES WILL OVERSPREAD THE REGION AND INTENSIFY. EXPECTATIONS OVER THE NEXT FEW HOURS ARE THAT STORMS WILL RAPIDLY DEVELOP AND INTENSIFY ALONG THE DRYLINE IN CENTRAL KS/OK AS THE STRONG 90KT MID LEVEL JET NOSES INTO THIS AREA. THE MAIN SHORTWAVE AXIS WILL SHIFT TO THE EAST AND STRONG 500MB HEIGHT FALLS AND SFC PRESSURE FALLS WILL OVERSPREAD THE REGION. PARTIAL CLEARING WILL HELP INCREASE TEMPS OVER THE WESTERN PORTIONS OF THE AREA AND WITH LOW 60S SFC DEWPOINTS...RESULT IN UP TO 1500 J/KG MLCAPE. SUPERCELLS ALONG THE DRYLINE WILL REMAIN DISCRETE AS IT MOVES INTO THE AREA. TIMING WISE...OUR THINKING HAS NOT CHANGED MUCH. SE KS/W MO WILL BE AFFECTED BY STORMS ROUGHLY BETWEEN 6-9PM...THE HIGHWAY 65 CORRIDOR BETWEEN 7PM-12AM...AND EASTERN PORTIONS OF THE AREA BETWEEN 9PM AND 2AM. LARGE HAIL...DAMAGING WINDS AND LARGE HAIL ARE EXPECTED AREA WIDE. AT THIS TIME...THE RISK FOR TORNADOES LOOKS GREATEST FOR AREAS ALONG AND WEST OF THE HIGHWAY 65 CORRIDOR. THE TORNADO RISK FOR AREAS EAST OF HIGHWAY 65 IS CONDITIONAL ON WHETHER OR NOT THESE STORMS CAN REMAIN SURFACE BASED. GIVEN THAT THIS AREA WILL HAVE A MORE LIMITED OPPORTUNITY TO RECOVER BEHIND THE INITIAL WAVE OF SHRA/TSRA MOVING THROUGH RIGHT NOW. FRIDAY/FRIDAY NIGHT...THE COLD CORE UPPER LOW WILL SLOW MEANDER THROUGH THE AREA DURING THE DAY. AT LEAST PARTIAL CLEARING IS EXPECTED AND TEMPS SHOULD QUICKLY WARM INTO THE 70S. STEEP LAPSE RATES ASSOCIATED WITH THE UPPER LOW WILL KEEP THE ATMOSPHERE UNSTABLE AND SCT TSRA ARE EXPECTED TO DEVELOP DURING THE AFTERNOON HOURS. WET BULB ZERO HGHTS WILL BE ON THE LOW SIDE AND THESE STORMS WILL RUN THE RISK OF MARGINALLY SEVERE HAIL. THIS ACTIVITY WILL SHIFT TO THE SOUTHEAST DURING THE EVENING AND OUT OF THE AREA FRIDAY NIGHT. NORTHERLY FLOW WILL STRENGTHEN OVERNIGHT AND LOWS WILL DROP INTO THE MID/UPPER 30S BY SAT MORNING. GAGAN LONG TERM (SATURDAY THROUGH TUESDAY NIGHT): ON SATURDAY THE MAIN UPPER SYSTEM FINALLY BEGINS TO FILL AND WEAKEN AS IT PUSHES SOUTHEAST OF THE REGION DURING THE MORNING HOURS. MUCH COOLER HIGHS CAN BE EXPECTED AS NORTHEAST FLOW TRANSPORTS IN 850MB TEMPERATURES COOLER THAN 5 DEG C. AFTER SEVERAL DAYS OF NEAR ABOVE NORMAL TEMPERATURES...GUIDANCE INDICATES THAT HIGHS IN THE 50S ARE LIKELY. WITH CLEAR SKIES AND LIGHT WINDS...THERE IS CONCERN FOR FROST ACROSS THE FORECAST AREA DURING THE PREDAWN HOURS SUNDAY MORNING. EXPECT LOWS IN THE UPPER 30S ALONG THE KANSAS BORDER WHERE SOUTHERLY WINDS MAY PICK UP A BIT AFTER MIDNIGHT. LOWER 30S ARE POSSIBLE ACROSS CENTRAL MISSOURI WHERE WINDS SHOULD BE LIGHTER...AS THIS AREA WILL BE CLOSER TO THE CENTER OF HIGH PRESSURE. THE UPPER FLOW WILL TRANSITION FROM ZONAL ON SUNDAY...TO SOUTHWESTERLY ON MONDAY AS ANOTHER UPPER LEVEL SYSTEM PUSHES INTO THE INTERMOUNTAIN WEST. THIS WILL RESULT IN A NICE WARMING TREND...AS HIGHS REACHING THE LOWER TO MIDDLE 70S ARE LIKELY MONDAY AND TUESDAY. GRIDS ARE DRY SATURDAY THROUGH MONDAY NIGHT. ADDED SOME LOW END CHANCE POPS TUESDAY AND TUESDAY NIGHT A FRONT AND UPPER SYSTEM APPROACH THE OZARKS REGION. MOISTURE RETURN DOESN'T LOOK ALL THAT GREAT AHEAD OF THE SYSTEM...SO HELD OFF ON HIGHER POPS AT THIS TIME. SAW && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION...UPDATED MESOSCALE DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 512 PM CDT THU APR 6 2006 ...SEVERE WEATHER OUTBREAK EXPECTED LATE THIS AFTERNOON AND TONIGHT... .MESOSCALE DISCUSSION... SUPERCELLS ALONG DRYLINE OVER EASTERN OKLAHOMA ARE PRODUCING TORNADOES IN OSAGE COUNTY. CURRENT 20Z SGF SOUNDING IS FAIRLY STABLE SHOWING LITTLE CAPE AND A -430 CINH. BUT WHEN WE MODIFIED THE SOUNDING WITH CURRENT SURFACE CONDITIONS OVER EASTERN KANSAS...CAPE EXPLODES TO ALMOST 2000 J/KG AND CINH DISAPPEARS. STILL HAVE A COUPLE HOURS OF HEATING...SO WE SHOULD GET CLOSE TO THE FORECAST SOUNDING OUTPUT. LAPS OUTPUT SHOWS TONGUE OF 1400+ J/KG SURFACE CAPES FROM NORTHEASTERN OKLAHOMA THROUGH WEST CENTRAL MISSOURI. NEODESHA NPN PROFILER SHOWS WINDS UP TO 75KTS AT 20K FEET WITH A 40KT SOUTHERLY LOW LEVEL JET RIGHT AROUND 5K FEET. HWO LOOKS GOOD WITH TORNADO PROBABILITY FORECAST FOR OUR CWA. THE EVENT IS ABOUT TO GET GOING HERE IN AN HOUR OR SO. GCC && .PREV DISCUSSION...302 PM SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT): COMPLEX WEATHER PATTERN EVOLVING OVER THE CENTRAL U.S. AT THIS TIME. CURRENT WAT VAP IMAGERY/RUC INITIALIZATION OF 500MB VORTICITY INDICATES THAT THE LEAD SHORT WAVE DISTURBANCE IS LIFTING THROUGH THE AREA. REGIONAL WSR 88D SHOWS THE ASSOCIATE COMPLEX OF SHRA/TSRA QUICKLY MOVING TO THE NORTHEAST THROUGH THE MO OZARKS. MEANWHILE... A VERY POTENT UPPER DISTURBANCE IS EMERGING INTO THE CENTRAL PLAINS. AT THE SFC...THE DRYLINE HAS SET UP OVER CENTRAL KS/OK AND PER LATEST VIS SAT IMAGERY...A CU FIELD IS DEVELOPING ALONG/AHEAD THIS FEATURE. INSOFAR AS MOISTURE IS CONCERNED...THE TODAY'S RAINFALL HAS MAINTAINED DECENT BL MOISTURE WITH UPPER 50S TO LOWER 60S SFC DEWPOINTS ACROSS THE REGION. JUST TO THE WEST...WHERE PARTIAL CLEARING HAS OCCURRED AHEAD OF THE DRYLINE...DEWPOINTS ARE IN THE LOW/MID 60S. THE LATEST RUC/NAM/GFS INDICATE THAT LOWER 60S WILL CONTINUE TO SPREAD INTO THE REGION THIS AFTERNOON. HEATING AND INSTABILITY HAVE BEEN LIMITED THUS FAR TODAY. OUR RAINFALL HAS SUCCESSFULLY HELD TEMPS IN THE MID 60S TO LOWER 70S...HOWEVER...OVER THE NEXT TWO HOURS THE COMPLEX OF SHRA/TSRA WILL EJECT TO THE EAST/NORTHEAST INTO E MO WILL SET UP A BRIEF BREAK IN THE ACTIVITY ACROSS THE REGION. SOME PARTIAL CLEARING IS EXPECTED DURING THE LATE AFTERNOON HOURS...PARTICULARLY OVER THE WESTERN SECTIONS OF THE CWFA WHICH WILL ALLOW FOR WARMING INTO THE MID TO UPPER 70S. EASTERN PORTIONS OF THE CWFA WILL HAVE LITTLE TIME TO WARM UP AFTER RAINFALL EXITS AND MAY MAKE IT BACK TO AROUND 70. ACCORDING TO SGF 15Z AND 18Z RAOBS...A RATHER STOUT CAP HAS BEEN WEAKENED A BIT. AFTER LOOKING AT THE 18Z RAOBS FROM TOP AND OUN (ALONG WITH A 45-50 KT LLJ SURGING INTO THE REGION) I EXPECT A BRIEF REINVIGORATION OF THE CAP. INSTABILITY THUS FAR HAS BEEN A FEW HUNDRED J/KG AND RATHER ELEVATED IN NATURE (ABOVE 700MB)...HOWEVER AS THE UPPER DISTURBANCE PIVOTS TO THE EAST...LAPSE RATES WILL STEEPEN AND MLCAPES WILL RISE TO BETWEEN 1000 AND 1500 J/KG. TREMENDOUS WIND ENERGY IS ASSOCIATED WITH THIS SYSTEM...A 110KT ULJ...A 90KT MID LEVEL JET...AND A 45KT LLJ. AS A RESULT...SHEAR IS HIGH. 0-6KM BULK SHEAR IS AROUND 75KTS...WITH 0-1KM SHEAR 20-30KTS. AS THE UPPER DISTURBANCE MOVES NORTHEAST THIS AFTERNOON AND EVENING...THESE SHEAR VALUES WILL OVERSPREAD THE REGION AND INTENSIFY. EXPECTATIONS OVER THE NEXT FEW HOURS ARE THAT STORMS WILL RAPIDLY DEVELOP AND INTENSIFY ALONG THE DRYLINE IN CENTRAL KS/OK AS THE STRONG 90KT MID LEVEL JET NOSES INTO THIS AREA. THE MAIN SHORTWAVE AXIS WILL SHIFT TO THE EAST AND STRONG 500MB HEIGHT FALLS AND SFC PRESSURE FALLS WILL OVERSPREAD THE REGION. PARTIAL CLEARING WILL HELP INCREASE TEMPS OVER THE WESTERN PORTIONS OF THE AREA AND WITH LOW 60S SFC DEWPOINTS...RESULT IN UP TO 1500 J/KG MLCAPE. SUPERCELLS ALONG THE DRYLINE WILL REMAIN DISCRETE AS IT MOVES INTO THE AREA. TIMING WISE...OUR THINKING HAS NOT CHANGED MUCH. SE KS/W MO WILL BE AFFECTED BY STORMS ROUGHLY BETWEEN 6-9PM...THE HIGHWAY 65 CORRIDOR BETWEEN 7PM-12AM...AND EASTERN PORTIONS OF THE AREA BETWEEN 9PM AND 2AM. LARGE HAIL...DAMAGING WINDS AND LARGE HAIL ARE EXPECTED AREA WIDE. AT THIS TIME...THE RISK FOR TORNADOES LOOKS GREATEST FOR AREAS ALONG AND WEST OF THE HIGHWAY 65 CORRIDOR. THE TORNADO RISK FOR AREAS EAST OF HIGHWAY 65 IS CONDITIONAL ON WHETHER OR NOT THESE STORMS CAN REMAIN SURFACE BASED. GIVEN THAT THIS AREA WILL HAVE A MORE LIMITED OPPORTUNITY TO RECOVER BEHIND THE INITIAL WAVE OF SHRA/TSRA MOVING THROUGH RIGHT NOW. FRIDAY/FRIDAY NIGHT...THE COLD CORE UPPER LOW WILL SLOW MEANDER THROUGH THE AREA DURING THE DAY. AT LEAST PARTIAL CLEARING IS EXPECTED AND TEMPS SHOULD QUICKLY WARM INTO THE 70S. STEEP LAPSE RATES ASSOCIATED WITH THE UPPER LOW WILL KEEP THE ATMOSPHERE UNSTABLE AND SCT TSRA ARE EXPECTED TO DEVELOP DURING THE AFTERNOON HOURS. WET BULB ZERO HGHTS WILL BE ON THE LOW SIDE AND THESE STORMS WILL RUN THE RISK OF MARGINALLY SEVERE HAIL. THIS ACTIVITY WILL SHIFT TO THE SOUTHEAST DURING THE EVENING AND OUT OF THE AREA FRIDAY NIGHT. NORTHERLY FLOW WILL STRENGTHEN OVERNIGHT AND LOWS WILL DROP INTO THE MID/UPPER 30S BY SAT MORNING. GAGAN LONG TERM (SATURDAY THROUGH TUESDAY NIGHT): ON SATURDAY THE MAIN UPPER SYSTEM FINALLY BEGINS TO FILL AND WEAKEN AS IT PUSHES SOUTHEAST OF THE REGION DURING THE MORNING HOURS. MUCH COOLER HIGHS CAN BE EXPECTED AS NORTHEAST FLOW TRANSPORTS IN 850MB TEMPERATURES COOLER THAN 5 DEG C. AFTER SEVERAL DAYS OF NEAR ABOVE NORMAL TEMPERATURES...GUIDANCE INDICATES THAT HIGHS IN THE 50S ARE LIKELY. WITH CLEAR SKIES AND LIGHT WINDS...THERE IS CONCERN FOR FROST ACROSS THE FORECAST AREA DURING THE PREDAWN HOURS SUNDAY MORNING. EXPECT LOWS IN THE UPPER 30S ALONG THE KANSAS BORDER WHERE SOUTHERLY WINDS MAY PICK UP A BIT AFTER MIDNIGHT. LOWER 30S ARE POSSIBLE ACROSS CENTRAL MISSOURI WHERE WINDS SHOULD BE LIGHTER...AS THIS AREA WILL BE CLOSER TO THE CENTER OF HIGH PRESSURE. THE UPPER FLOW WILL TRANSITION FROM ZONAL ON SUNDAY...TO SOUTHWESTERLY ON MONDAY AS ANOTHER UPPER LEVEL SYSTEM PUSHES INTO THE INTERMOUNTAIN WEST. THIS WILL RESULT IN A NICE WARMING TREND...AS HIGHS REACHING THE LOWER TO MIDDLE 70S ARE LIKELY MONDAY AND TUESDAY. GRIDS ARE DRY SATURDAY THROUGH MONDAY NIGHT. ADDED SOME LOW END CHANCE POPS TUESDAY AND TUESDAY NIGHT A FRONT AND UPPER SYSTEM APPROACH THE OZARKS REGION. MOISTURE RETURN DOESN'T LOOK ALL THAT GREAT AHEAD OF THE SYSTEM...SO HELD OFF ON HIGHER POPS AT THIS TIME. SAW && .AVIATION... THE BULK OF SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS AFTERNOON WILL PASS TO THE EAST AND SOUTHEAST OF THE JOPLIN AND SPRINGFIELD TERMINALS AFTER THIS WAVE OF PRECIPITATION PUSHES OFF TO THE EAST...THERE SHOULD BE A BREAK OF SEVERAL HOURS BEFORE STRONG/SEVERE CONVECTION MOVES IN FROM THE WEST. DID TWEAK TIMING BACK AND HOUR OR TWO...WHICH STILL MIGHT NOT BE ENOUGH AS THE DRYLINE IS STILL WEST OF ICT. IT IS LOOKING NOW AS IF THE BEST CHANCE OF ADDITIONAL THUNDERSTORMS WILL BE AFTER 00Z. SAW .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 830 PM CDT THU APR 6 2006 FORECAST CHALLENGE CONCERNS WIND HEADLINES...PCPN AND TEMPERATURES. WINDS THIS EVENING HAVE STRUGGLED TO REACH ADVISORY CRITERIA AND WITH LOSS OF HEATING DO NOT FEEL WINDS WILL INCREASE SIGNIFICANTLY AS STRONGEST CORE OF WINDS WILL BE SOUTH OF BORDER. WILL CANCEL CURRENT WIND ADVISORY WITH UPDATE. BAND OF SHRA OVER NE SD/FAR SE ND SHRINKING AND WILL CONTINUE TREND OF ENDING PCPN AROUND MIDNIGHT AS RUC PUSHES DRYING THROUGH COLUMN TO BORDER AREA BY 06Z. LIGHTNING ALSO ON THE WANE WITH NO RECENT HITS OVER SE ND. SO FAR PCPN HAS BEEN VERY LIGHT WITH AMOUNTS <.10 ALONG DAKOTAS BORDER. COLD ADVECTION TO CONTINUE OVERNIGHT AND IN SPITE OF WIND HOLDING UP AND SOME CLOUD COVER OVERNIGHT DEGREE OF LOW LEVEL DRYING SHOULD ALLOW FOR TEMPERATURES TO COOL BLO FREEZING MOST AREAS. AT THIS TIME TEMPERATURES LOOK REASONABLE. && .HYDROLOGY... REFER TO BISFLSFGF PRODUCTS ON OUR HOME PAGE FOR FURTHER INFORMATION ON THE ONGOING FLOODING IN THE RED RIVER VALLEY AND ASSOCIATED TRIBUTARIES. NEXT CHANCE OF SHOWERS APPEARS TO BE LATE MONDAY INTO TUESDAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...AREAL FLOOD WARNINGS FOR ALL COUNTIES IN THE RED RIVER VALLEY UNTIL FRIDAY. MN...AREAL FLOOD WARNINGS FOR ALL COUNTIES IN THE RED RIVER VALLEY UNTIL FRIDAY. && $$ VOELKER nd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 910 PM MDT THU APR 6 2006 .DISCUSSION...VIGOROUS UPPER LEVEL LOW SPINNING OVER CENTRAL NE PER WATER VAPOUR LOOP. SURFACE LOW NEAR KOFK. STRONG LIFT CONTINUES WITH LARGE CIRCULATION...SPREADING PRECIPITATION OVER MUCH OF THE CWA THIS EVENING. 00Z NAM/RUC CONTINUES THESE CONDITIONS OVERNIGHT... SUPPORTED BY SATELLITE/RADAR TRENDS. PRESSURE GRADIENT CONTINUES TO TIGHTEN WITH 35-50KT 850MB WINDS FORECAST FROM WEST TO EAST ACROSS THE SD PLAINS. CURRENT WIND HEADLINES IN GOOD SHAPE. CALLS TO SPOTTERS IN THE HILLS INDICATE CHANGEOVER OCCURRING ABOVE 4500 FEET...BUT LITTLE OR NO ACCUMULATION ON GRASSY SURFACES. ROADS JUST WET SO FAR. CHANGEOVER WILL CONTINUE OVERNIGHT...BUT WARMISH TEMPERATURES WILL LIMIT POTENTIAL ACCUMULATIONS OF THIS SYSTEM. HOWEVER...2 TO 6 INCHES STILL IN THE REALM OF POSSIBILITIES AS FROUDE NUMBERS APPROACH 1 LATER TONIGHT...SUGGESTING SOME UPSLOPE POTENTIAL. LOCAL AMOUNTS MAY BE HIGHER ABOVE 5500 FEET...WITH LESSER AMOUNTS BELOW 4500. ON THE WY PLAINS AND ADJACENT SD PLAINS...MINOR ACCUMULATIONS EXPECTED. MAIN CHANGE TO UPDATE WAS TO LINGER PRECIPITATION IN THE SOUTH LONGER AND STRONGER ACROSS THE FAR SOUTH EARLY FRIDAY MORNING. REST OF FORECAST CHANGES TWEAKS. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY FOR THE NRN/CTL BLACK HILLS UNTIL 15Z FRI. WIND ADVISORY FOR THE SD PLAINS UNTIL 15Z FRI. WY...WINTER WEATHER ADVISORY FOR THE WY BLACK HILLS UNTIL 15Z FRI. && $$ HELGESON sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 245 PM MDT THU APR 6 2006 .DISCUSSION...WATER VAPOR IMAGERY SHOWING BROAD UPPER LOW ACROSS EASTERN WYOMING NOW SLIDING SOUTHEAST INTO NEBRASKA. SURFACE ANALYSIS SHOWING LOW PRES NOW OVER EASTERN NEBRASKA WITH A SURFACE TROUGH STRETCHING ACROSS THE CENTER OF THE CWA. THIS TROUGH HAS REMAINED OVER THE AREA THROUGH MUCH OF THE DAY...AND HAS BEEN THE FOCUS OF CONVECTIVE ACTIVITY TODAY. TONIGHT...PRECIP ACROSS THE NRN HALF OF THE CWA WILL FINALLY BEGIN SLIDING SOUTH AS DYNAMICS CONTINUE TO SHIFT SOUTH ALONG THE BACK END OF THE UPPER LOW. RUC 850-700 MUCAPE HAS DONE RELATIVELY WELL TODAY SHOWING LOCATION OF CONVECTION THIS AFTERNOON. IT ALSO SHOWS BULK OF CONVECTION TRANSITIONING TO THE SERN PORTIONS OF THE CWA BY MIDNIGHT TONIGHT. LATEST OBS SHOWING NEAR ADVISORY WINDS ACROSS NORTH DAKOTA. THESE STRONGER WINDS WILL ALSO SLIDE SOUTH THROUGH TONIGHT AS THE PRESSURE GRADIENT INCREASES. MAV AND MOS HAVE HAD FAIRLY GOOD AGREEMENT ON WINDS REACHING ADVISORY CRITERIA TONIGHT ACROSS THE PLAINS...SO WILL ISSUE WIND ADVISORY UNTIL 15Z TOMORROW. AS THE N/NE WINDS INCREASE AND COOLER AIR BEGINS TO WORK ITS WAY INTO THE HILLS...UPSLOPE ENHANCED PRECIP WILL DEVELOP. GFS CONTINUES TO TREND WITH WARMER TEMPS AT 700 MB TONIGHT KEEPING SNOW ACCUM TOTALS TO JUST 4 INCHES. ON THE OTHER HAND...ETA STILL WANTS TO BRING COOLER AIR TO THE AREA WHICH WOULD BRING UP TO A FOOT OF SNOW IN THE HILLS TONIGHT. TEMPS ACROSS HIGHER ELEVATIONS ARE NOW IN THE MID 30S...SO IT WONT TAKE LONG TO REACH FREEZING TONIGHT. FOR NOW WILL GO WITH 3-6 INCH WORDING FOR THE HILLS WITH LOCALLY HIGHER AMOUNTS ABOVE 5500 FEET. THEREFORE WINTER WEATHER ADVISORY WILL BE ISSUED TONIGHT FOR NRN/CTL BLACK HILLS AND ALSO WY BLACK HILLS. A DRYING TREND WILL BE THE STORY TOMORROW. DRY AIR WILL QUICKLY MOVE ACROSS THE AREA TOMORROW AS HIGH PRESSURE BUILDS IN FROM THE NORTH. MOST OF THE PRECIP ACROSS WRN SD SHOULD BE ENDING BY MID MORNING...WITH SOUTHERN ZONES CLEARING OUT AROUND NOON. WINDS ARE ALSO EXPECTED TO REACH BELOW CRITERIA THRESHOLD BY MID MORNING. WARM AIR WILL ADVECT IN SATURDAY AND REBOUND OUR TEMPS INTO THE UPPER 60S TO LOWER 70S. SAT NIGHT...A SHORTWAVE IS PROGGED TO MOVE ACROSS THE CWA GIVING THE AREA A LITTLE QPF. GFS HAD THIS FEATURE ACROSS CENTRAL MT YESTERDAY...SO DECIDED AGAINST PUTTING POPS IN UNTIL SOMETHING CONSISTENT IS SEEN. FOR NOW...JUST SOME PASSING CLOUDS POSSIBLE WITH THIS SHORTWAVE. EXTENDED...UPR RIDGE ON SUNDAY WILL GIVE WAY TO INCREASING SW FLOW MONDAY AS NEXT TROF APPROACHES THE NRN PLAINS. LOW POPS STILL LK REASONABLE FOR MON THRU EARLY TUE EVENING. AN UPR RIDGE WL BRIEFLY BUILD INTO THE REGION WED BEFORE THE NEXT UPPER TROF MOVES INTO GREAT BASIN BRINGING SW FLOW ALOFT AGAIN ON THURS AND FRI WITH ANOTHER LOW CHANCE FOR PCPN FM LATE WED NIGHT INTO FRI. TEMPS LOOK TO REMAIN AT OR ABV SEASONAL NORMS FOR SUNDAY THROUGH THURSDAY BEFORE BEGINNING TO COOL OFF ON FRIDAY. && .AVIATION...CONDITIONS ACRS WRN SD/ WRN NEB AND WRN ND WILL BEGIN TO DETERIORATE LATE THIS AFT WITH IFR/MVFR CIGS DUE TO CLDS/PCPN AFT 22Z AS WIDESPREAD PCPN DVLPS ACRS THIS AREA. CONDITIONS WILL BEGIN TO IMPROVE AFTER 15Z FRIDAY. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY FOR THE NRN/CTL BLACK HILLS UNTIL 15Z FRI. ...WIND ADVISORY FOR THE SD PLAINS UNTIL 15Z FRI. WY...WINTER WEATHER ADVISORY FOR THE WY BLACK HILLS UNTIL 15Z FRI. && $$ CALDERON/CZEPYHA sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 1040 AM MDT THU APR 6 2006 .DISCUSSION...SURFACE ANALYSIS CURRENTLY SHOWING TROUGH STRETCHING FROM THE FAR SERN ZONES ACROSS THE HILLS AND INTO NE WY. SRN HALF OF THE CWA HAS GOTTEN DRY SLOTTED THIS MORNING WHILE THE NRN HALF HAS SEEN PLENTY OF RAIN SHOWERS ALONG WITH SCATTERED THUNDERSTORMS. THESE THUNDERSTORMS HAVE HAD SMALL CONCENTRATED CORES WHICH HAVE LIKELY BEEN DROPPING SMALL HAIL. MUCAPE SUGGESTS SCT ELEVATED TSTORMS WILL CONTINUE INTO THE AFTERNOON HOURS ACROSS NWRN SD. AS DYNAMICS BEGIN TO SHIFT SWRD LATER THIS AFTN...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP ALONG THE SURFACE TROUGH NEAR AND ALONG THE SD/NE BORDER. RUC HAS EASED OFF WITH SURFACE CAPE IN THIS AREA SINCE STRATUS DECK IS NOW KEEPING THIS AREA COOLER THAN FORECASTED. SO THE EXPECTED CONVECTION THIS AFTERNOON OVER SC SD WILL LIKELY ALSO BE ELEVATED IN NATURE. BIG QUESTION IS HOW SOON SHOWERS/STORMS WILL DEVELOP ACROSS THE SRN ZONES. 88D SHOWING SHOWERS ALREADY DEVELOPING WRN/CTRL PENNINGTON...SO COULD BE SOONER THAN LATER. && .AVIATION...TSTMS WILL MOVE NORTHEAST ACRS THE SD PLAINS THRU 20Z WITH SOME SMALL HAIL AND GUSTY WINDS POSS. CONDITIONS ACRS WRN SD/ WRN NEB AND WRN ND WILL BEGIN TO DETERIORATE LATE THIS AFT WITH IFR/MVFR CIGS DUE TO CLDS/PCPN AFT 22Z AS WIDESPREAD PCPN DVLPS ACRS THIS AREA. CONDITIONS WILL BEGIN TO IMPROVE AFTER 15Z FRIDAY. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ CALDERON/CZEPYHA sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1039 AM CDT THU APR 6 2006 .UPDATE...ONGOING ELEVATED CONVECTION SLOWLY LIFTING NORTH ACROSS THE FORECAST AREA...WITH REDEVELOPMENT ALREADY NOTED ACROSS CENTRAL SOUTH DAKOTA. HAVE HAD A COUPLE OF SEVERE HAIL REPORTS SO FAR WITH THIS SCATTERED ELEVATED CONVECTION. LAPSE RATES BETWEEN 800HPA AND 500HPA REMAIN QUITE SUPPORTIVE OF STRONG UPDRAFTS...WITH GOOD UPPER LEVEL DIVERGENCE NOTED IN LATEST RUC DATASET THROUGH 18Z ACROSS THE CENTRAL AND WESTERN FORECAST AREA. THE NEXT VORT LOBE IN WATER VAPOR IMAGERY THAT COULD POTENTIALLY INDUCE ANOTHER ROUND OF CENTRAL NEBRASKA TO SOUTH CENTRAL SOUTH DAKOTA THUNDERSTORMS WILL BE LIFTING NORTHEAST INTO THE NEBRASKA PANHANDLE OVER THE NEXT 6 TO 9 HOURS. THE WIND ADVISORY STILL LOOKS ON TRACK AS A POTENT BACKDOOR COLD FRONT DROPS SOUTH OUT OF NORTH DAKOTA AND WESTERN MINNESOTA THIS EVENING AND OVERNIGHT. 925HPA CAA TO THE TUNE OF ABOUT 15 DEGREES CELSIUS IN 12 HOURS BETWEEN 00Z FRIDAY AND 12Z FRIDAY...WITH A STRONG 3 AND 6-HOURLY ISALLOBARIC WIND COMPONENT TO BOOT. MAY HAVE TO NUDGE THE START TIME UP A COUPLE HOURS IF LATEST LAMP GUIDANCE PANS OUT. DORN .PREVIOUS DISCUSSION... SHORT TERM...TODAY THROUGH SATURDAY NIGHT THE BIGGEST CHALLENGE FACING THE NEAR TERM DEALS WITH PCPN COVERAGE AND TYPE TODAY THRU TONIGHT. CURRENTLY MODELS ARE TAKING 5H LOW FURTHER TO SOUTH THAN PREVIOUSLY THOUGHT..AND -TSRA JUST NOW REACHING FAR SW CWA. LATEST DAY1 OUTLOOK FROM SPC JUST CLIPS FAR SERN CWA. BEST INSTABILITY OCCURS THRU MORNING ACROSS SRN TO SE CWA WITH RESPECTABLE 7H-5H LAPSE RATES FROM 6 TO 7 DEGREES C. NAM MOST UNSTABLE CAPE VALUES REACH 500 J/KG BY 18Z WITH BEST LI'S AROUND -1. BY 00Z FRIDAY THESE VALUES FALL OFF DRAMATICALLY AS DRY AIR BEGINS TO PUSH IN FROM NORTH. FOR NORTHERN COUNTIES...QUESTION REMAINS ON WHEN CONVECTIVE PCPN WILL PHASE OVER TO STRATIFORM TYPE AS 85H AND 7H TROWAL FEATURES TAKE OVER. THESE ALSO BOTH SLIP RAPIDLY SOUTH BY 00Z AS SFC AND 5H LOWS TAKE MORE SOUTHERLY ROUTE. ALSO WELL PRONOUNCED DRY PUNCH NOW ADVECTING THROUGH WRN NEB/WRN SD WITH SAT PIC SHOWING CLEAR SKIES. KEPT HIGHEST PROBABILITY PCPN TO THE SOUTHERN/WESTERN COUNTIES DURING DAY...TAPERING CHCS DOWN TO THE NE PART OF CWA. NEXT CONCERN IS WINDS TONIGHT. AS LOW SLOWLY SLIPS SOUTH...STRONG HIGH BUILDS IN FROM NORTH. MAV GUIDANCE SHOWING SUSTAINED WINDS AT OR ABOVE 30KTS FOR MANY PLACES. GIVEN STRENGTH OF SUBSIDENCE BEHIND EXITING SYSTEM AND CAA TAKING PLACE..SEE NO REASON TO DISCOUNT. WILL ISSUE A WIND ADVRY FOR ALL CWA FROM 00Z TO 12Z FRIDAY. THIS MAY BE A LITTLE LONG TIME WISE...BUT WOULD RATHER RUN LONG THAN HAVE LATER SHIFTS EXTEND ADVRY FOR AN HOUR OR TWO TO COVER. CLEARING EXPECTED RAPIDLY TONIGHT AND TRENDED POPS QUICKLY OUT OF CWA OVERNIGHT. REMAINDER OF NEAR TERM QUIET. BUILDING HEIGHTS AND WAA RETURNS TO CWA BY SATURDAY MORNING. MODELS DO PROG ANOTHER WAVE PASSING THROUGH CWA SATURDAY NIGHT...BUT LITTLE SEEN IN THE WAY OF MOISTURE WITH FEATURE. MIGHT BE A FEW ACCAS AS IT PASSES OVERHEAD BUT DON'T EXPECT MUCH MORE THAN THAT. .LONG TERM...SUNDAY THROUGH WEDNESDAY MODELS IN FAIR AGREEMENT DURING THIS PERIOD. IT STARTS OFF WITH A WEAK SURFACE TROUGH IN THE AREA ON SUNDAY AND A WEAK DISTURBANCE PASSING TO THE NORTH SUNDAY NIGHT. A BROAD...AND RATHER FLAT...UPPER RIDGE WILL BE OVER THE CENTRAL U.S. ON SUNDAY. THE RIDGE WILL DRIFT EAST ON SUNDAY AND MONDAY AS AN UPPER TROUGH MAKES PROGRESS ACROSS THE WESTERN CONUS. MODELS AGREE THAT THIS UPPER TROUGH AND ITS SURFACE LOW WILL MOVE THROUGH THE CENTRAL AND NORTHERN PLAINS MONDAY NIGHT THROUGH TUESDAY NIGHT. HAVE CONTINUED WITH SLIGHT CHANCE POPS FOR NOW...BUT THIS MAY NEED TO BE INCREASED THE STRENGTH/TRACK OF THIS SYSTEM BECOMES MORE CERTAIN. MODELS DO VARY IN THE AMOUNT OF COLD AIR BEHIND THIS SYSTEM HOWEVER. WENT WITH A MODEL BLEND FOR TEMPS BY THE END OF THE PERIOD. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY 00Z FRIDAY TO 12Z FRIDAY ALL COUNTIES. MN...WIND ADVISORY 00Z FRIDAY TO 12Z FRIDAY FOR BIG STONE AND TRAVERSE COUNTIES. && $$ HINTZ/KNUTSVIG sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 1026 AM CDT THU APR 6 2006 .UPDATE... WE ARE EXPANDING THE HIGH WIND WARNING SOUTH. UPDATED PRODUCTS WILL BE TRANSMITTED SOON. A POTENTIALLY SIGNIFICANT WIND/WILDFIRE EVENT APPEARS TO BE COMMENCING OVER THE SOUTH PLAINS REGION. THIS GIVEN THE ONSET OF HIGH WIND CRITERIA WINDS AND RED FLAG CONDITIONS DURING THE 9 AM HOUR. SATELLITE/RADAR DATA HAS ALREADY DEPICTED EVIDENCE OF BLOWING DUST AND A FIRE IN EASTERN LYNN COUNTY. THE WHITE SANDS PROFILER IS DEPICTING 70KT 700MB WINDS. THIS IS STRONGER THAN NAM/RUC SOLUTIONS...AND SUPPORTS AN INCREASED HIGH WIND THREAT FOR THE SOUTHERN ZONES. THIS IS ADDITIONALLY SUPPORTED BY CURRENT WEST TEXAS MESONET OBS THAT ALREADY SHOW SEVERE/NEAR SEVERE WINDS IN THOSE ZONES. && .PREV DISCUSSION... (ISSUED 342 AM CDT THU APR 6 2006) SHORT TERM... UPPER LOW NEAR THE 4-CORNERS CONTINUES TO MOVE TO THE EAST WITH PACIFIC COLD FRONT EXPECTED TO SWEEP THROUGH THE FORECAST AREA THIS MORNING. EFFICIENT MIXING SHOULD OCCUR BEHIND THE FRONT WITH CLEAR SKIES AND STRONG SUBSIDENCE EXPECTED. 700 MB JET MAX EJECTS SOUTH OF OUR AREA...BUT BOTH THE NAM AND GFS INDICATE A SECONDARY MAXIMA OVER THE SOUTH PLAINS AT MIDDAY. GRADIENT AND MAGNITUDE OF WINDS THAT WILL GET MIXED DOWN SUGGEST SEVERE WIND GUSTS A DISTINCT PROBABILITY...PARTICULARLY ON THE HIGHER TERRAIN OF THE WESTERN SOUTH PLAINS. WILL LEAN TOWARD THE GFS WITH ITS SLIGHTLY HIGHER WIND SPEED POTENTIAL GIVEN ITS BETTER INITIALIZATION OF MID AND UPPER LEVEL WINDS OVER THE SWRN CONUS. WILL THUS UPGRADE THE HIGH WIND WATCH TO A WARNING AND EXPAND THE INHERITED ADVISORY TO INCLUDE THE SERN THREE COUNTIES AS WELL. DO NOT HAVE A GOOD FEEL FOR BLOWING DUST POTENTIAL GIVEN RECENT RAINS...BEGINNING OF SOME VEGETATIVE GROWTH AND THE STRONG COLD ADVECTION THAT IS NOT USUALLY FAVORABLE FOR A SIGNIFICANT DUST EVENT. WOULD NOT BE SURPRISED TO SOME LOCAL AREAS WITH DUST PROBLEMS...BUT AM NOT CONFIDENT ENOUGH IN WIDESPREAD SUB-1 MILE VISIBILITY TO ISSUE A BLOWING DUST ADVISORY ATTM. REMAINDER OF THE FCST IS IN GOOD SHAPE AS WELL. DOWNSLOPING WILL SOMEWHAT OFFSET COLD ADVECTION...BUT THE COLD ADVECTION WILL STILL BE STRONG ENOUGH TO KNOCK AROUND 10 DEGREES OR MORE OFF OF YESTERDAYS HIGHS. WINDS WILL DROP OFF SOME NEAR SUNSET BUT WILL LIKELY STAY UP IN THE 10 TO 20 MPH MOST OF THE NIGHT AS LOW LEVEL GRADIENT STAYS TIGHT AND FULL DECOUPLING OF THE BOUNDARY LAYER LOOKS UNLIKELY. LONG TERM... TIGHTLY WOUND STORM SYSTEM CENTERED OVER EASTERN KANSAS 12Z FRI PROGGED TO DROP SOUTH SOUTHEAST TWD ARK/LA/TEX DURING THE DAY...THUS MAINTAINING A STRONG H85-70 GRADIENT ACROSS NORTHERN WEST TEXAS. SHORTLY AFTER SUNRISE...DEEP MIXING WILL AGAIN COMMENCE WITH NORTHWEST SFC WINDS INCREASING TO 25-30 MPH WITH GUSTS AROUND 40 MPH OVER THE SOUTHERN PANHANDLE. ATTM...WINDSPEEDS LOOK TO BE JUST BELOW ADVISORY CRITERIA LEVEL OVER THE SOUTHEAST TX PANHANDLE...WITH BEST CHC OF RED FLAG WARNING CRITERIA OVER THE SOUTHWEST CWFA DUE TO LOW RH/S. WILL LET LATER SHIFTS EVALUATE FOR POSSIBLE WIND/FIRE WATCHES AND WARNINGS. VERY NICE WEATHER ON TAP FOR THE WEEKEND AS H50 RIDGE BUILDS INTO THE SOUTHERN PLAINS WITH TEMPS WARMING BACK TO ABOVE NORMAL ON SUNDAY. MINOR WAVE TO TRANSLATE MAINLY NORTH OF THE AREA MONDAY NIGHT INTO TUESDAY WILL BRING ANOTHER INCREASE IN HIGH CLOUDS. AGREE WITH PREVIOUS SHIFT OF KEEPING POPS ONLY AT 10 PERCENT DUE TO LACK OF MOISTURE. STRONGER UPPER LEVEL SYSTEM STILL FORECAST TO DROP INTO THE DESERT SOUTHWEST BY MID WEEK. AS THIS SYSTEM MOVES EAST...MAY SEE AN INCREASE IN TSTM ACTIVITY BY LATE THURS OR FRIDAY. FIRE WEATHER... EXPECT THAT RED FLAG CRITERIA SHOULD EASILY BE MET TODAY WITH POTENTIAL FOR EXTREMELY CRITICAL CONDITIONS FOR RAPID FIRE GROWTH GIVEN EXPECTED MAGNITUDE OF THE WINDS. ONLY CONCERN IS IF DEW POINTS STAY ABOUT 5 DEGREES HIGHER THAN EXPECTED. HUMIDITY VALUES WOULD THEN BE MARGINAL BUT THIS SITUATION WILL BE DRIVEN BY THE STRONG WINDS REGARDLESS. RED FLAG WARNING WILL REMAIN UNCHANGED. && .LUB WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 7 PM THURSDAY FOR THE FOLLOWING ZONES: BAILEY...BRISCOE...CASTRO...COCHRAN...CROSBY...FLOYD...GARZA... HALE...HOCKLEY...LAMB...LUBBOCK...LYNN...PARMER...SWISHER... TERRY...AND YOAKUM. RED FLAG WARNING UNTIL 9 PM THURSDAY FOR THE FOLLOWING ZONES: BAILEY...BRISCOE...CASTRO...CHILDRESS...COCHRAN...COTTLE... CROSBY...DICKENS...FLOYD...GARZA...HALE...HALL...HOCKLEY... KENT...KING...LAMB...LUBBOCK...LYNN...MOTLEY...PARMER... STONEWALL...SWISHER...TERRY...AND YOAKUM. WIND ADVISORY UNTIL 7 PM THURSDAY FOR THE FOLLOWING ZONES: CHILDRESS...COTTLE...DICKENS...HALL...KENT...KING...MOTLEY...AND STONEWALL. && $$ 08/20 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 237 PM CDT THU APR 6 2006 .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES TONIGHT AND INTO FRIDAY MORNING...THEN TEMPERATURES THROUGH WEEKEND. LATEST WATER VAPOR SATELLITE IMAGERY INDICATING UPPER LEVEL LOW OVER COLORADO AND WYOMING...AND UPPER LEVEL TROUGH OVER HUDSON BAY. LATEST 19Z SURFACE ANALYSIS INDICATING SURFACE LOW OVER SOUTHERN NEBRASKA AND NORTH CENTRAL KANSAS. WARM FRONT EXTENDED SOUTHEAST FROM SURFACE LOW INTO SOUTHERN IOWA AND NORTHERN MISSOURI. LATEST MOSAIC RADAR INDICATING SHOWERS EXTENDED FROM NORTHERN ILLINOIS BACK INTO CENTRAL MINNESOTA. THIS IS IN RESPONSE TO 850MB WARM FRONT AND MOISTURE CONVERGENCE...AS INDICATED BY THE LATEST 18Z PROFILER DATA BETWEEN WOOD LAKE MINNESOTA...BLUE RIVER WISCONSIN AND SLATER IOWA. LATEST 12Z THURSDAY NAM AND GFS ARE IN PRETTY GOOD AGREEMENT WITH INITIALIZATION OF UPPER LEVEL TROUGH OVER WYOMING AND COLORADO PER LATEST WATER VAPOR IMAGERY. OVERALL...BOTH MODELS IN PRETTY GOOD AGREEMENT IN MOVING UPPER LEVEL LOW OVER THE ROCKY MOUNTAINS INTO THE SOUTHERN PLAINS STATES BY 00Z SATURDAY...AND QUICKLY MOVING UPPER LEVEL TROUGH OVER HUDSON BAY SOUTH INTO THE GREAT LAKES REGION. CONFIDENCE IN FORECAST IS MODERATE. TONIGHT...SURFACE LOW OVER SOUTHERN NEBRASKA AND CENTRAL KANSAS DEEPENS RAPIDLY OVER NORTHEASTERN KANSAS BY 12Z FRIDAY WITH WARM FRONT EXTENDING EAST INTO CENTRAL ILLINOIS. UPPER LEVEL TROUGH OVER HUDSON BAY WILL MOVE SOUTH INTO THE GREAT LAKES REGION. THIS WILL ALLOW FOR A VERY NARROW DEFORMATION BAND OF PRECIPITATION TO DEVELOP ACROSS NORTHERN IOWA AND EXTREME SOUTHWEST WISCONSIN. WITHIN THIS BAND...BOTH THE 12Z THURSDAY NAM AND GFS INDICATING STRONG AND DEEP QG FORCING OVER THIS AREA...AND TIME HEIGHT CROSS SECTIONS INDICATING CLOSE TO 20 UBAR/KM OF VERTICAL MOTION OVER NORTHEAST IOWA BETWEEN 09Z AND 12Z. WITH THIS FORCING IN MIND...LOOKING AT RAINFALL AMOUNTS OF ONE TO TWO INCHES ACROSS NORTHEAST IOWA AND EXTREME SOUTHWEST WISCONSIN. THIS WOULD RESULT IN MINOR RISES ALONG AREA RIVERS AT THIS TIME ACROSS NORTHEAST IOWA AND EXTREME SOUTHWEST WISCONSIN. LATEST RUC INDICATING 500-1000 J/KG OF 0-6KM MOST UNSTABLE CAPE ACROSS NORTHEAST IOWA THROUGH 03Z FRIDAY...THOUGH BEST SHEAR IS LOCATED ALONG AND SOUTH OF WARM FRONT ACROSS SOUTHERN IOWA. FEEL THERE IS ENOUGH INSTABILITY TO CONTINUE WARRANT ISOLATED THUNDERSTORMS ACROSS FORECAST AREA TONIGHT AND WILL CONTINUE TO MENTION. UPPER LEVEL TROUGH OVER GREAT LAKES REGION WILL PUSH SURFACE LOW FARTHER SOUTH INTO THE CENTRAL PLAINS BY 18Z FRIDAY. THIS WILL ALLOW FOR STRONG VERTICAL MOTION TO MOVE SOUTH AND FOR SURFACE RIDGE WITH GOOD SUBSIDENCE TO BUILD INTO FORECAST AREA BY 00Z SATURDAY. BOTH MODELS INDICATING GOOD COLD AIR ADVECTING INTO THE FORECAST AREA LATE FRIDAY AND INTO FRIDAY NIGHT. TREND OF COOLER TEMPERATURES AND DECREASING CLOUDS ARE HANDLED WELL WITH PREVIOUS FORECAST. SURFACE RIDGE BUILDS INTO THE OHIO RIVER VALLEY SATURDAY NIGHT AND SUNDAY. FORECAST AREA UNDER SOUTHERLY FLOW ALOFT AND AT SURFACE. COMBINED WITH WEAK WARM AIR ADVECTING INTO UPPER MIDWEST AND GREAT LAKES REGION. FORECAST AREA WILL SEE TEMPERATURES REBOUND AND BE CLOSER TO NORMAL SUNDAY. .LONG TERM...MONDAY THROUGH THURSDAY MAIN FORECAST CONCERNS ARE TIMING PRECIPITATION CHANCES MIDDLE OF NEXT WEEK. BOTH THE 00Z THURSDAY ECMWF AND GFS ARE IN PRETTY GOOD AGREEMENT THROUGH 00Z TUESDAY...THEN BEGIN TO DIFFER ON TIMING OF UPPER LEVEL SHORTWAVE TROUGH FOR MIDDLE OF NEXT WEEK. FEEL THE 00Z THURSDAY GFS A LITTLE TOO FAST WITH SHORTWAVE TROUGH...WHILE THE 00Z THURSDAY CANADIAN IS IN BETWEEN THE GFS AND ECMWF. WILL LEAN MORE TOWARD A SLOWER ECMWF AND CANADIAN SOLUTION. UPPER LEVEL TROUGH DEEPENS OVER THE WESTERN U.S. THROUGH PERIOD. THIS WILL AMPLIFY UPPER LEVEL RIDGE OVER THE EASTERN HALF OF THE U.S. SHORTWAVE TROUGH EMBEDDED IN SOUTHWESTERLY FLOW ALOFT WILL MOVE INTO THE HIGH PLAINS BY 00Z WEDNESDAY. DECENT MOISTURE AND ENOUGH INSTABILITY ASSOCIATED WITH SHORTWAVE TROUGH WILL ALLOW FOR SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE FORECAST AREA TUESDAY AFTERNOON INTO WEDNESDAY NIGHT. HAVE REMOVED PRECIPITATION CHANCES FOR MONDAY NIGHT DUE TO SLOWER TREND OF SHORTWAVE TROUGH AND BEST FORCING WEST OF FORECAST AREA. STRONG SOUTHERLY FLOW ALOFT WILL ALLOW FOR GOOD WARM AIR TO ADVECT INTO THE UPPER MIDWEST AND GREAT LAKES REGION EARLY NEXT WEEK. THIS ALLOWS TEMPERATURES TO BE SLIGHTLY ABOVE NORMAL INTO MIDDLE OF NEXT WEEK. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DTJ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 400 AM EDT FRI APR 7 2006 .SHORT TERM... OUR MAIN SHORT TERM FCST CHALLENGE IS TO DETERMINE OUR PROBABILITIES FOR RAIN AND CONVECTION TODAY. WE ALSO NEED TO EVALUATE POTENTIAL FOR ANY SNOW THIS AFTERNOON INTO THIS EVENING. RAIN FINALLY MOVED INTO OUR AREA AFTER MIDNIGHT ONCE THE WARM FRONT MOVED CLOSER AND THE ATMOSPHERE IN THE LOWER LEVELS FINALLY MOISTENED UP. RGNL RADAR TRENDS AND 00Z GUIDANCE QPF SUGGESTS RAIN WILL BECOME STEADIER AND CONTINUE ACROSS OUR CENTRAL AND SOUTHERN CWA FOR THE NEXT SEVERAL HOURS WITH JUST A CHC OF LIGHTER RAIN SHOWERS ACROSS OUR FAR NNE COUNTIES. POTENTIAL REMAINS HIGH FOR A STEADY F-GEN RAIN BAND OF MODERATE INTENSITY TO SET UP RIGHT OVER OUR CENTRAL AND SOUTHERN CWA AND REGIONAL RADAR TRENDS SUGGEST THIS IS ALREADY BEGINNING TO OCCUR. THIS FRONTOGENETICALLY FORCED RAIN BAND WITH EMBEDDED CONVECTION WILL CONTINUE TO DEVELOP DUE TO STRONG MID LEVEL (AROUND 700 MB) INSTABILITY AND 700 MB F VECTOR CONVERGENCE AND RESULTING LIFT WHICH WILL BECOME QUITE VIGOROUS. THE SHARP BAROCLINIC ZONE IN THE LOWER LEVELS REALLY TIGHTENS UP THROUGH THE DAY AND WE WILL HAVE NICE ISENTROPIC UPGLIDE NORTH OF THE SFC BOUNDARY. A GFS TIME HEIGHT X-SECTION SHOWS DEEP MOISTURE (> 90%) WILL PERSIST THROUGH MOST OF THIS AFTN (ALTHOUGH NNE SFC WINDS WILL ADVECT DRIER AIR IN NEAR THE SFC). OVERALL THOUGH TIME HEIGHT RH PROGS AND FCST SOUNDINGS APPEAR FAVORABLE FOR RAIN TO CONTINUE THROUGH THE AFTERNOON CENTRAL AND SOUTH. SNOW POTENTIAL WITH THE EVOLUTION OF THIS F-GEN BAND ACROSS OUR CENTRAL CWA HAS DECREASED SOMEWHAT DUE TO A COMBINATION OF TIMING AND STRENGTH OF CAA. LATEST 13KM RUC GUIDANCE SHOWS P-TYPE TO BE ALL RAIN THROUGH THIS AFTERNOON AND NUMERICAL GUIDANCE NUMBERS ALSO GENERALLY SHOW PCPN WILL FALL IN LIQUID FORM MOST OF THE AFTERNOON SOUTH OF A LINE FROM MKG TO MOP. NAM GUIDANCE IS LIKELY A LITTLE TOO AGGRESSIVE IN HOW QUICKLY IT LOWERS 1000-850 MB CRITICAL THICKNESS VALUES. RAIN SHOWERS WILL MIX WITH THEN CHANGE OVER TO SNOW SHOWERS FAR NORTH THIS AFTN. SOME SNOW FLAKES MAY BECOME MIXED IN WITH RAIN ACROSS OUR CENTRAL CWA LATE THIS AFTERNOON... BUT FOR ALL INTENTS AND PURPOSES... I NOW EXPECT P-TYPE TO BE MAINLY RAIN WITH THE MAIN F-GEN BAND. WE WILL INCLUDE MENTION OF SCATTERED CONVECTION ALONG WITH THE RAIN TODAY CENTRAL AND SOUTH DUE TO STRENGTH OF 700 MB F-GEN... MID LEVEL INSTABILITY... AND STEEP LAPSE RATES ALOFT AS THE NORTHERN STREAM H5 TROF SWINGS IN FROM THE NW. I BELIEVE SCATTERED AREAS OF ELEVATED CONVECTION ACROSS SOUTH CENTRAL WI ARE LIKELY A HARBINGER OF THINGS TO COME FOR OUR AREA A BIT LATER THIS MORNING INTO THIS AFTERNOON. THE ELEVATED CONVECTION OFF TO OUR WEST IS ALSO BEING AIDED BY TREMENDOUS UPPER DIVERGENCE. THIS ACTIVITY COULD ALSO BE AIDED A BIT BY TILTING AND STRETCHING OF 500-300 MB VORTICITY (I.E. DEFORMATION ZONE) IN BETWEEN THE NORTHERN AND SOUTHERN STREAM UPPER LEVEL SYSTEMS LATER TODAY. THEREFORE I BELIEVE IT IS WISE TO INCLUDE MENTION OF CONVECTION TO TODAY/S FCST FOR OUR CENTRAL AND SOUTHERN CWA. I DO NOT EXPECT ANY SVR WX SINCE THE HAIL THREAT WITH THIS ELEVATED CONVECTION IS MINIMAL DUE TO MID LEVEL LAPSE RATES (700-500 MB) OF ONLY 5-6 DEGREES C/KM. THE FCST FOR THE REMAINDER OF THE SHORT TERM PERIOD IS MUCH MORE STRAIGHTFORWARD. LINGERING LIGHT PCPN THIS EVENING (MAINLY SOUTH) WILL QUICKLY COME TO AN END AS NORTHERLY FLOW CONTINUES TO ADVECT DRIER AIR INTO OUR AREA. HIGH PRESSURE WILL DOMINATE OUR WX SATURDAY AND PRODUCE CLEAR TO PARTLY CLOUDY SKIES (A SCT STRATOCU DECK SHOULD DEVELOP LATE MORNING AND AFTERNOON AS SUGGESTED BY THE NAM CU SCHEME). MAX TEMPS SATURDAY WILL ONLY REACH THE LOW TO MID 40S FOLLOWED BY UNSEASONABLY COLD TEMPS FOR SATURDAY NIGHT AS SKIES CLEAR AND WINDS GO LIGHT AND VARIABLE. THE SFC HIGH PRESSURE RIDGE WILL PRODUCE A LOT OF SUN WITH MILDER TEMPS FOR SUNDAY. .LONG TERM... MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT IN SHOWING A LARGE SURFACE HIGH SLIPPING OFF TO THE EAST ON MONDAY AND TUESDAY. THIS RESULTS IS A LOW LEVEL SOUTHERLY RETURN FLOW OVER THE GREAT LAKES REGION AND MODERATING TEMPERATURES. WE SHOULD BE AROUND 60 FOR HIGHS ON MONDAY AND WELL INTO THE 60S ON TUESDAY. ACTUALLY THE POTENTIAL EXISTS TO REACH INTO THE 70S ON TUESDAY AS MODELS SUGGEST THE LOW LEVEL JET WILL BE QUITE STRONG IN BETWEEN THE EAST COAST RIDGE AND FRONTAL SYSTEM MOVING IN THE PLAINS. SHOWER AND THUNDERSTORM POTENTIAL BEGINS TO INCREASE TUESDAY NIGHT AND ESPECIALLY WEDNESDAY AS THE AFOREMENTIONED FRONTAL SYSTEM APPROACHES AND A SHORTWAVE MOVES ENE FROM THE NRN PLAINS. THE SURFACE FRONT LOOKS TO SLOW/STALL OVER THE AREA WEDNESDAY NIGHT AND THURSDAY AND EVENTUALLY BECOME ORIENTED IN MORE OF A WEST TO EAST FASHION AS THE UPPER FLOW TAKES ON A MORE ZONAL STRUCTURE. THIS PATTERN SHOULD RESULT IN THE POTENTIAL FOR A FEW ADDITIONAL SHOWER AND THUNDERSTORMS EPISODES LATE NEXT WEEK WITH GENERALLY MILD CONDITIONS PREVAILING. && .GRR WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY NEARSHORE WATERS ST. JOSEPH TO MANISTEE 8 AM THIS MORNING THROUGH TONIGHT. && $$ LAURENS MEADE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 332 AM EDT FRI APR 7 2006 .DISCUSSION... THE MAIN CONCERNS WITH THIS FORECAST PACKAGE ARE WITH THE WINDS TODAY AND THE CHANCE OF PRECIPITATION TONIGHT. WATER VAPOR IMAGERY AND RUC/NAM SHOWING DEEP LOWS OVER NORTHEAST KANSAS AND OVER SOUTHERN JAMES BAY...WITH A RIDGE SEPARATING THESE EXTENDING FROM THE OHIO RIVER VALLEY THROUGH WISCONSIN...INTO NORTH DAKOTA. ANOTHER RIDGE EXTENDS FROM THE SOUTHERN ROCKIES THROUGH MONTANA INTO THE CANADIAN PRAIRIES. SURFACE ANALYSIS SHOWING A LOW OVER SOUTHEAST NEBRASKA. A FRONTAL SYSTEM EXTENDS EAST FROM THIS LOW THROUGH THE LOWER GREAT LAKES INTO SOUTHWEST QUEBEC. A FRONT ALSO RUNS WEST FROM THE NEBRASKA LOW THROUGH WYOMING AND WESTERN MONTANA. A BROAD RIDGE IS OVER CENTRAL CANADA. THE JAMES BAY MID LEVEL LOW WILL SHIFT INTO SOUTHWEST QUEBEC... WHILE THE LOW OVER NORTH KANSAS SLIDES INTO OKLAHOMA TODAY. A WEAK SHORTWAVE WRAPPING AROUND THE JAMES BAY LOW WILL SWEEP THROUGH THE FORECAST AREA. SOUNDINGS SHOWING AN INVERSION AT AROUND 3.5K FEET. CONDITIONS ARE VERY DRY ABOVE THE INVERSION BUT RATHER HIGH RH JUST BELOW THIS LEVEL. THEREFORE...EXPECT CONSIDERABLE LOW CLOUDS. THE FORECAST MODELS SHOW THAT IT WILL CONTINUE TO BE FAIRLY DRY AT THE SURFACE. THEREFORE...THE SNOW WILL HAVE TO SATURATE OUT THE LOW LEVELS BEFORE GETTING TO THE SURFACE. SURFACE TO 900MB LAPSE RATE WILL BE ON THE ORDER OF 8.5-9.5C/KM. STRONGEST 900MB OMEGA WILL BE NORTH OF M-28 FROM KIWD TO KSAW. I WILL BE LOOKING FOR A CHANCE OF SOME FLURRIES THERE TODAY. A WARMING AT THE SURFACE WILL REDUCE CHANCE OF PRECIPITATION IN THE AFTERNOON...AS THE RH LOWERS THROUGH THE DAY. THE LOW LEVEL INVERSION WILL ALLOW SOME OF WINDS AT 925MB TO MIX TO SURFACE ESPECIALLY OVER LAKE SUPERIOR. SO WILL KEEP SOME BREEZY GUSTY CONDITIONS THROUGH THE DAY. ANOTHER SHORTWAVE ROTATING THROUGH THE BASE OF THE QUEBEC LOW WILL SWEEP THROUGH THE FORECAST AREA TONIGHT. THE CANADIAN SURFACE WILL SLIDE OVER THE NORTHERN AND CENTRAL PLAINS. THE LAYER AROUND 900MB WILL REMAIN FAIRLY MOIST WHICH WILL HELP IN PRODUCING SOME PRECIPITATION. MODELS SOUNDINGS CONTINUE TO SHOW NEARLY DRY AT THE SURFACE...AND SURFACE-900MB LAPSE RATE AROUND 8.5C/KM. TEMPERATURES WILL BE WELL BELOW FREEZING...THEREFORE...LOOKING FOR A CHANCE OF SOME LIGHT SNOW OR FLURRIES OVERNIGHT. TRAJECTORY FORECAST AND GUIDANCE INDICATE THAT THE OVERNIGHT LOWS SHOULD DIP INTO THE MID TO LOW 20S WHICH WITH THE EXPECTED WINDS AND CLOUDY CONDITIONS SOUND REASONABLE. ANOTHER VERY WEAK SHORTWAVE WILL SWEEP THROUGH THE AREA ON SATURDAY. THE SURFACE RIDGE WILL EXPAND TO BLANKET THE UPPER GREAT LAKES ON SATURDAY AND SLIDE INTO THE OHIO RIVER VALLEY ON SUNDAY. THE AIR MASS WILL BE VERY STABLE AND DRY WHICH WILL KEEP FAIR CONDITIONS THROUGH THE WEEKEND. THE MID LEVEL RIDGE WILL WEAKEN AS IT SLIDE OVER THE UPPER GREAT LAKES ON SUNDAY NIGHT. A WEAK SHORTWAVE SHIFTING THROUGH THIS RIDGE WILL BE OVER THE FORECAST AREA SUNDAY NIGHT. A LOW WILL DEVELOP OVER THE NORTHERN PLAINS WITH A COLD FRONT. A SOUTHWEST FLOW WILL OCCUR ON THE BACKSIDE OF THE RIDGE DRAWING WARMER MOIST AIR FROM THE GULF INTO THE AREA. THE NORTHERN PLAINS LOW WILL MOVE INTO THE FORECAST AREA LATE ON TUESDAY AND BRING AN INCREASE CHANCE OF SHOWERS TO THE REGION. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 344 AM CDT FRI APR 7 2006 .DISCUSSION... CONVECTION CURRENTLY OVER SOUTH CENTRAL MINNESOTA IS CORRELATED WITH Q VECTOR CONVERGENCE ON THE RUC MODEL. THE RUC MODEL SUGGESTS THAT THIS WILL GRADUALLY SAG SOUTH OF OUR COUNTY WARNING AREA BETWEEN 15Z AND 18Z THIS MORNING. IT WILL BE A RAW DAY BETWEEN THE WINDS AND COOLER TEMPERATURES. WILL STAY THE COURSE WITH A WIND ADVISORY OVER WEST CENTRAL AND SOUTH CENTRAL MINNESOTA THIS MORNING. THIS ADVISORY IS CORRELATED WITH AN AREA OF PEAK WINDS AT 925 MB AND AN AREA OF SURFACE PRESSURE RISES...BOTH FORECAST BY THE NAM MODEL. THE SURFACE TRAJECTORY FORECAST SUGGESTS THAT TEMPERATURES WILL HOLD FAIRLY STEADY THAN BEGIN TO FALL BEFORE THE END OF THE DAY. BOTH THE NAM AND GFS MODELS INDICATE FAIR WEATHER TONIGHT THROUGH SATURDAY NIGHT WITH A HIGH PRESSURE RIDGE PASSING ACROSS THE AREA. RETURN SOUTHERLY FLOW IS EXPECTED TO BEGIN SUNDAY. A SHORT WAVE EMBEDDED IN THE MID LEVEL FLOW IS FORECAST TO CROSS OUR FORECAST AREA FROM WEST TO EAST ON SUNDAY. THIS FEATURE IS NOT EXPECTED TO PRODUCE ENOUGH LIFT FOR MORE THEN JUST PASSING CLOUDS. LONGER TERM...MONDAY THROUGH THURSDAY NIGHT FOLLOWED THE SLOWER ECMWF MODEL OVERALL THAN THE GFS MODEL ENSEMBLE DURING THE PERIOD. UPPER RIDGE IS FORECAST TO PUSH OFF TO THE EAST OVER THE WESTERN GREAT LAKES REGION BY MONDAY EVENING. SOUTHWEST AIRFLOW ALOFT DEVELOP OR COMMENCE OVER THE WESTERN HALF OF THE NATION INTO THE UPPER MIDWEST. MODELS HAVE BEEN CONSISTENT IN BRINGING A SERIES OF SHORTWAVE UPPER TROUGHS OVER THE UPPER MIDWEST EARLY IN THE WEEK. KEPT THE MENTION OF SHRA/TSRA FOR MONDAY NIGHT INTO WEDNESDAY. BY DAY 6...MORE OF A ZONAL UPPER FLOW DEVELOP OVER THE NORTHERN PLAINS AND MIDWEST. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL NOON CDT TODAY FOR BLUE EARTH-BROWN- FARIBAULT-FREEBORN-LE SUEUR-MARTIN-NICOLLET-SIBLEY-STEELE- WASECA-WATONWAN COUNTIES. WIND ADVISORY UNTIL 10 AM CDT THIS MORNING FOR CHIPPEWA-DOUGLAS- KANDIYOHI-LAC QUI PARLE-POPE-REDWOOD-RENVILLE-STEVENS-SWIFT-YELLOW MEDICINE COUNTIES. WI...NONE. && $$ mn AREA FORECAST DISCUSSION...UPDATED AVIATION DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 1233 AM CDT FRI APR 7 2006 .MESOSCALE DISCUSSION... THUNDERSTORMS HAVE GRADUALLY WEAKENED AS THEY MOVED AWAY FROM THE DRYLINE NEAR THE KANSAS BORDER INTO A MORE STABLE AIRMASS OVER SOUTH CENTRAL MO. A FEW MORE SMALL HAILERS OR BRIEF WIND GUSTS TO 50 MPH WILL BE POSSIBLE AS THE STORMS EXIT HOWELL/OREGON/SHANNON/ TEXAS/DENT COUNTIES OVER THE HOUR OR SO. DIRECTIONAL AND SPEED SHEAR REMAIN VERY STRONG OVER THE AREA...SO WILL LIKELY WAIT UNTIL STORMS HAVE COMPLETELY CLEARED THE AREA BEFORE LETTING TORNADO WATCH GO. TERRY && .AVIATION... FOR 06Z TAFS...WILL CONTINUE PREDOMINANT VFR CONDITIONS THROUGH THE FORECAST PERIOD. DRY SLOT HAS SPREAD ACROSS THE WESTERN HALF OF MISSOURI AS LOW PRESSURE SYSTEM STALLS TEMPORARILY OVER THE CENTRAL PLAINS. ONCE THE SYSTEM PUSHES SOUTHEAST INTO THE MISSOURI VALLEY BY FRIDAY AFTERNOON...MAY NEED TO ADD THUNDER FOR 18Z TO 00Z FRIDAY. TERRY && .PREV DISCUSSION...302 PM SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT): COMPLEX WEATHER PATTERN EVOLVING OVER THE CENTRAL U.S. AT THIS TIME. CURRENT WAT VAP IMAGERY/RUC INITIALIZATION OF 500MB VORTICITY INDICATES THAT THE LEAD SHORT WAVE DISTURBANCE IS LIFTING THROUGH THE AREA. REGIONAL WSR 88D SHOWS THE ASSOCIATE COMPLEX OF SHRA/TSRA QUICKLY MOVING TO THE NORTHEAST THROUGH THE MO OZARKS. MEANWHILE... A VERY POTENT UPPER DISTURBANCE IS EMERGING INTO THE CENTRAL PLAINS. AT THE SFC...THE DRYLINE HAS SET UP OVER CENTRAL KS/OK AND PER LATEST VIS SAT IMAGERY...A CU FIELD IS DEVELOPING ALONG/AHEAD THIS FEATURE. INSOFAR AS MOISTURE IS CONCERNED...THE TODAY'S RAINFALL HAS MAINTAINED DECENT BL MOISTURE WITH UPPER 50S TO LOWER 60S SFC DEWPOINTS ACROSS THE REGION. JUST TO THE WEST...WHERE PARTIAL CLEARING HAS OCCURRED AHEAD OF THE DRYLINE...DEWPOINTS ARE IN THE LOW/MID 60S. THE LATEST RUC/NAM/GFS INDICATE THAT LOWER 60S WILL CONTINUE TO SPREAD INTO THE REGION THIS AFTERNOON. HEATING AND INSTABILITY HAVE BEEN LIMITED THUS FAR TODAY. OUR RAINFALL HAS SUCCESSFULLY HELD TEMPS IN THE MID 60S TO LOWER 70S...HOWEVER...OVER THE NEXT TWO HOURS THE COMPLEX OF SHRA/TSRA WILL EJECT TO THE EAST/NORTHEAST INTO E MO WILL SET UP A BRIEF BREAK IN THE ACTIVITY ACROSS THE REGION. SOME PARTIAL CLEARING IS EXPECTED DURING THE LATE AFTERNOON HOURS...PARTICULARLY OVER THE WESTERN SECTIONS OF THE CWFA WHICH WILL ALLOW FOR WARMING INTO THE MID TO UPPER 70S. EASTERN PORTIONS OF THE CWFA WILL HAVE LITTLE TIME TO WARM UP AFTER RAINFALL EXITS AND MAY MAKE IT BACK TO AROUND 70. ACCORDING TO SGF 15Z AND 18Z RAOBS...A RATHER STOUT CAP HAS BEEN WEAKENED A BIT. AFTER LOOKING AT THE 18Z RAOBS FROM TOP AND OUN (ALONG WITH A 45-50 KT LLJ SURGING INTO THE REGION) I EXPECT A BRIEF REINVIGORATION OF THE CAP. INSTABILITY THUS FAR HAS BEEN A FEW HUNDRED J/KG AND RATHER ELEVATED IN NATURE (ABOVE 700MB)...HOWEVER AS THE UPPER DISTURBANCE PIVOTS TO THE EAST...LAPSE RATES WILL STEEPEN AND MLCAPES WILL RISE TO BETWEEN 1000 AND 1500 J/KG. TREMENDOUS WIND ENERGY IS ASSOCIATED WITH THIS SYSTEM...A 110KT ULJ...A 90KT MID LEVEL JET...AND A 45KT LLJ. AS A RESULT...SHEAR IS HIGH. 0-6KM BULK SHEAR IS AROUND 75KTS...WITH 0-1KM SHEAR 20-30KTS. AS THE UPPER DISTURBANCE MOVES NORTHEAST THIS AFTERNOON AND EVENING...THESE SHEAR VALUES WILL OVERSPREAD THE REGION AND INTENSIFY. EXPECTATIONS OVER THE NEXT FEW HOURS ARE THAT STORMS WILL RAPIDLY DEVELOP AND INTENSIFY ALONG THE DRYLINE IN CENTRAL KS/OK AS THE STRONG 90KT MID LEVEL JET NOSES INTO THIS AREA. THE MAIN SHORTWAVE AXIS WILL SHIFT TO THE EAST AND STRONG 500MB HEIGHT FALLS AND SFC PRESSURE FALLS WILL OVERSPREAD THE REGION. PARTIAL CLEARING WILL HELP INCREASE TEMPS OVER THE WESTERN PORTIONS OF THE AREA AND WITH LOW 60S SFC DEWPOINTS...RESULT IN UP TO 1500 J/KG MLCAPE. SUPERCELLS ALONG THE DRYLINE WILL REMAIN DISCRETE AS IT MOVES INTO THE AREA. TIMING WISE...OUR THINKING HAS NOT CHANGED MUCH. SE KS/W MO WILL BE AFFECTED BY STORMS ROUGHLY BETWEEN 6-9PM...THE HIGHWAY 65 CORRIDOR BETWEEN 7PM-12AM...AND EASTERN PORTIONS OF THE AREA BETWEEN 9PM AND 2AM. LARGE HAIL...DAMAGING WINDS AND LARGE HAIL ARE EXPECTED AREA WIDE. AT THIS TIME...THE RISK FOR TORNADOES LOOKS GREATEST FOR AREAS ALONG AND WEST OF THE HIGHWAY 65 CORRIDOR. THE TORNADO RISK FOR AREAS EAST OF HIGHWAY 65 IS CONDITIONAL ON WHETHER OR NOT THESE STORMS CAN REMAIN SURFACE BASED. GIVEN THAT THIS AREA WILL HAVE A MORE LIMITED OPPORTUNITY TO RECOVER BEHIND THE INITIAL WAVE OF SHRA/TSRA MOVING THROUGH RIGHT NOW. FRIDAY/FRIDAY NIGHT...THE COLD CORE UPPER LOW WILL SLOW MEANDER THROUGH THE AREA DURING THE DAY. AT LEAST PARTIAL CLEARING IS EXPECTED AND TEMPS SHOULD QUICKLY WARM INTO THE 70S. STEEP LAPSE RATES ASSOCIATED WITH THE UPPER LOW WILL KEEP THE ATMOSPHERE UNSTABLE AND SCT TSRA ARE EXPECTED TO DEVELOP DURING THE AFTERNOON HOURS. WET BULB ZERO HGHTS WILL BE ON THE LOW SIDE AND THESE STORMS WILL RUN THE RISK OF MARGINALLY SEVERE HAIL. THIS ACTIVITY WILL SHIFT TO THE SOUTHEAST DURING THE EVENING AND OUT OF THE AREA FRIDAY NIGHT. NORTHERLY FLOW WILL STRENGTHEN OVERNIGHT AND LOWS WILL DROP INTO THE MID/UPPER 30S BY SAT MORNING. GAGAN LONG TERM (SATURDAY THROUGH TUESDAY NIGHT): ON SATURDAY THE MAIN UPPER SYSTEM FINALLY BEGINS TO FILL AND WEAKEN AS IT PUSHES SOUTHEAST OF THE REGION DURING THE MORNING HOURS. MUCH COOLER HIGHS CAN BE EXPECTED AS NORTHEAST FLOW TRANSPORTS IN 850MB TEMPERATURES COOLER THAN 5 DEG C. AFTER SEVERAL DAYS OF NEAR ABOVE NORMAL TEMPERATURES...GUIDANCE INDICATES THAT HIGHS IN THE 50S ARE LIKELY. WITH CLEAR SKIES AND LIGHT WINDS...THERE IS CONCERN FOR FROST ACROSS THE FORECAST AREA DURING THE PREDAWN HOURS SUNDAY MORNING. EXPECT LOWS IN THE UPPER 30S ALONG THE KANSAS BORDER WHERE SOUTHERLY WINDS MAY PICK UP A BIT AFTER MIDNIGHT. LOWER 30S ARE POSSIBLE ACROSS CENTRAL MISSOURI WHERE WINDS SHOULD BE LIGHTER...AS THIS AREA WILL BE CLOSER TO THE CENTER OF HIGH PRESSURE. THE UPPER FLOW WILL TRANSITION FROM ZONAL ON SUNDAY...TO SOUTHWESTERLY ON MONDAY AS ANOTHER UPPER LEVEL SYSTEM PUSHES INTO THE INTERMOUNTAIN WEST. THIS WILL RESULT IN A NICE WARMING TREND...AS HIGHS REACHING THE LOWER TO MIDDLE 70S ARE LIKELY MONDAY AND TUESDAY. GRIDS ARE DRY SATURDAY THROUGH MONDAY NIGHT. ADDED SOME LOW END CHANCE POPS TUESDAY AND TUESDAY NIGHT A FRONT AND UPPER SYSTEM APPROACH THE OZARKS REGION. MOISTURE RETURN DOESN'T LOOK ALL THAT GREAT AHEAD OF THE SYSTEM...SO HELD OFF ON HIGHER POPS AT THIS TIME. SAW && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 340 AM CDT FRI APR 7 2006 .SHORT TERM (TODAY-SUN)...CONVECTION IN SD/SOUTHERN MN SPREAD A CIRRUS SHIELD OVER US ON THU BUT THE CIRRUS IS QUICKLY THINNING AFTER THE END OF TSTORMS. IT APPEARS THAT IT WILL THIN OUT IN TIME TO MAKE EASTERN ND AND NORTH HALF OF MN FULLY SUNNY TO START TODAY. KMVX RADAR CONTINUES SHOWING A 45 KNOT LOW LEVEL JET AT 2 KFT AGL WHICH IS NICELY DECOUPLED AND SHEARED FROM SURFACE OVER AN INVERSION. MODELS SHOW 900 MB TEMPERATURES OVER FARGO DROPPING 5C FROM 12Z TO 18Z WHICH WILL SIMPLY MODIFY THE INVERSION TO AN ISOTHERMAL LAYER ABOVE 875 MB FOR THE AFTERNOON. BUT EXPECT THE WIND WILL STAY DECOUPLED UNTIL LATE MORNING WHEN RUC SHOWS THE SURFACE TO 850 MB PRESSURE GRADIENT DROPPING QUICKLY. EXPECT CURRENT BREEZY CONDITIONS TO PERSIST MOST OF THE DAY THOUGH WE MIGHT GET A BRIEF GUSTY PERIOD LATE IN THE MORNING. COOL/DRY ADVECTION WILL PREVENT TEMPERATURES FROM REACH 50F. LITTLE ELSE OF CONCERN THROUGH THE WEEKEND WITH MOSTLY SUNNY DAYS... CLEAR NIGHTS AND WARMER (HIGHS IN THE 50S) THAN SEASONAL LEVELS. A WEAK 500 MB SHORTWAVE IS EXPECTED TO PASS OVER ON SUN BUT 850 MB DEW POINTS WILL ONLY REACH ZERO OR SO WHILE SURFACE FEATURES ARE ALSO WEAK. .LONG TERM (MON-THU)...NEXT CHANCE OF PRECIPITATION FIGURES TO BE LATE MON INTO TUE WITH THE UPPER RIDGE HAVING MOVED TO THE GREAT LAKES AND AS BETTER LOOKING SHORTWAVE ARRIVES FROM THE SOUTHWEST. GFS PUSHES 850 MB DEW POINTS TO +8C...SHOWS A 35-40 KNOT 850 MB JET ALONG WITH SHOWALTERS FALLING BELOW ZERO AND AN 850/300 MB JET COUPLET TO MAKE IT INTERESTING. THESE FEATURES DON/T LOOK COINCIDENT ENOUGH FOR CONVECTION TO BE A LARGE THREAT BUT APPEARS THAT THE NORTH VALLEY WOULD BE MOST LIKELY SO INCREASED POP TO HIGH CHANCE THERE. AND CERTAINLY ENOUGH INSTABILITY TO MENTION THUNDER BY EVENING AND OVERNIGHT. THIS SHORTWAVE STAYS PROGRESSIVE AND SOME DRY ADVECTION WILL SHUT OFF CHANCE OF SHOWERS AGAIN LATE TUE UNTIL WED. && .HYDROLOGY... REFER TO BISFLSFGF PRODUCTS ON OUR HOME PAGE FOR FURTHER INFORMATION ON THE ONGOING FLOODING IN THE RED RIVER VALLEY AND ASSOCIATED TRIBUTARIES. NEXT CHANCE OF SHOWERS APPEARS TO BE LATE MONDAY INTO TUESDAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...AREAL FLOOD WARNINGS FOR ALL COUNTIES IN THE RED RIVER VALLEY UNTIL FRIDAY. MN...AREAL FLOOD WARNINGS FOR ALL COUNTIES IN THE RED RIVER VALLEY UNTIL FRIDAY. && $$ GV nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 440 AM EDT FRI APR 7 2006 .SHORT TERM(TDY-SUN)... AN OCCLUDING LOW IS LOCATED ACROSS SE NE THIS MORNING WITH A WARM FRONT EXTENDING THROUGH SOUTHERN IN AND INTO KY. WARM ADVECTION TYPE SHRA ARE OVERSPREADING THE CWA. DEWPOINTS HAD BEEN JUST BARELY 30F...BUT WITH THE APPROACH OF THE PRECIPITATION...HAVE QUICKLY JUMPED INTO THE UPPER 40S. TEMPS THE MORNING ARE RUNNING AROUND THE 50 DEGREE MARK. HOW THIS AFTERNOON PANS OUT WILL BE INTERESTING. COMPLICATED SETUP SPATIALLY ACROSS THE CWA. BAROCLINIC ZONE SETS UP RIGHT ACROSS THE CWA WITH A TIGHTENING TEMPERATURE GRADIENT/FRONTOGENESIS. BELIEVE FRONT WILL LAY ACROSS NORTHERN OHIO WITH THE STABLE LAKE KEEPING IT OVER LAND...AND MODELS ARE CONSISTENT WITH ITS POSITION. A WAVE WILL DEVELOP ALONG THE FRONT AS A NORTHERN STREAM TROUGH MAKES ITS WAY SOUTH ACROSS THE GREAT LAKES...PHASING WITH THE OPENING/FILLING CENTRAL PLAINS LOW BY THE TIME THEY REACH THE APPALACHIANS. THIS WILL TAKE THE FRONTAL BOUNDARY SOUTHEAST AS A COLD FRONT THIS AFTERNOON. MID LEVEL DRYING/WARM SECTOR HEATING/ STRONG PROFILE MAY VERY WELL PRIME THE SOUTHERN PORTION OF THE CWA THIS AFTERNOON FOR THE POSSIBILITY OF SEVERE...IN TIME FOR THE COLD FROPA. ADDED SEVERE WORDING TO THESE SOUTHERN ZONES. TO THE NORTH WILL MAINTAIN JUST A CHANCE OF THUNDERSTORMS ON THE ELEVATED SIDE. TEMPS WILL RANGE FROM THE MID 50S ALONG THE LAKE TO POSSIBLY 70 SOUTH OF BJJ/MFD. PRECIPITATION WILL EXIT TONIGHT...POSSIBLY MIXING WITH/CHANGING TO SNOW FOR SOME LOCATIONS DEPENDING ON THE TIMING OF THE COLDER AIR INTO THE AREA. IT WILL BE DRY BY SAT WITH AFTERNOON CU...THEN CLEARING. TEMPS WILL DIP BELOW AVERAGE TONIGHT AND SAT...AND BELOW FREEZING FOR SAT NIGHT WITH CLEAR SKIES AND HIGH PRESSURE. DRY AND WARMER FOR SUNDAY. && .AVIATION(06Z-06Z)... SIGNIFICANT AVIATION FORECAST ISSUES OVER THE NEXT 24 HOURS. LATEST SURFACE ANALYSIS SHOWS THE WARM FRONT STILL FROM MO THRU SRN IL INTO WRN KY. THE RUC AND THE NAM ARE VERY INSISTANT IN DRIVING THE FRONT NORTHEASTWARN OVER THE NEXT 6 HRS...WITH IT BEING POSITIONED FROM NRN INDIANA THRU CENTRAL OH BY 12Z. MEANWHILE...LOW PRES DEVELOPS AT THE TRIPLE POINT OVR NRN IN BY 12Z WHICH HELPS TO STALL THE FRONT OVR NRN OH UNTIL THE LOW PASSES EAST AND ALLOWS THE FRONT TO SHIFT SOUTH. PCPN IS CURRENTLY SPREADING INTO THE SWRN FORECAST AREA. EXPECT THIS PCPN TO SLOWLY SPREAD E-NE OVERNIGHT AS THE WARM FRONT MOVES NE. BY 12Z...NEARLY THE WHOLE FORECAST AREA WILL HAVE PCPN...BUT IT WILL TAKE AWHILE TO START ESPECIALLY AT ERI AND YNG DUE TO THE VERY DRY LOW LVL AIRMASS. EVENTUALLY...ALL SITES SHOULD DROP TO IFR. LIFR IS NOT OUT OF THE QUESTION IN THE HEAVIEST SHOWERS BUT CURRENTLY NO UPSTREAM SITES ARE REPORTING LIFR SO I HAVE OPTED TO LEAVE OUT OF THE FCST ATTM. NO THUNDER REPORTED EITHER AND WITH LACK OF ANY ELEVATED OR SFC INSTABILITY OVERNIGHT...HAVE OPTED TO REMOVE THUNDER FROM THE TAFS THRU 14Z. THE MODELS ARE IN GOOD AGREEMENT IN SHOWING THE FRONT HANGING UP JUST SOUTH OF THE LAKE ERIE SHORELINE WHICH MAKES SENSE GIVEN THE COLD LAKE. THIS WILL ALLOW FOR THE SRN PART OF THE FORECAST AREA TO SEE SOME DRY AIR AFT 14Z WHICH MAY ALLOW THE CIGS AT THE SOUTHERN SITES TO RISE TO TO MVFR. IN FACT...IT WOULD NOT BE TOTALLY SURPRISING TO ME IF THE SOUTHERN SITES SEE VFR CONDITIONS FRI MRNG AS THE WARM FRONT STAYS N OF THE AREA...ESPECIALLY SINCE SITES S OF THE WARM FRONT ARE VFR ATTM. HOWEVER...THIS PARTIAL CLEARING WILL ALSO SERVE TO DESTABILIZE THE ATMOSPHERE S OF THE FRONT FRI AFTN WHICH SHOULD HELP A LINE OF STORMS TO DEVELOP. BEST CHANCE FOR STORMS WILL BE GENERALLY ALONG AND SOUTH OF US224. COULD SEE SOME ELEVATED STORMS N OF THE WARM FRONT WITH THE NAM SHOWING ELEVATED CAPE VALUES AROUND 1000 J/KG AT KCLE AND KTOL. HOWEVER...CONFIDENCE OF THIS IS A LITTLE TOO LOW TO INCLUDE TSRA AT TOL/CLE/ERI ATTM. IF THE NAM THERMODYNAMIC AND KINEMATIC PROFILES VERIFY SOUTH OVER THE SOUTHERN HALF OF THE FORECAST AREA...SEVERE STORMS ARE CERTAINLY POSSIBLE. IF THE SRN PART OF THE FORECAST AREA SEES CLEARING TODAY...GUSTY SWLY WINDS WILL ALSO BE AN ISSUE. BUFKIT SHOWS GUSTS 25-35KT IN THE WARM SECTOR LATER THIS MRNG INTO THIS AFTN. BEHIND THE FRONT...THERE SHOULD BE PLENTY OF LOW LVL STRATUS TO DEAL WITH THROUGH 06Z WITH IFR CONDITIONS. MAY BE SOME SNOW SHOWERS AFT 00Z AT TOL...BUT THEY SHOULD BE MINOR AND LATER FORECASTS CAN LOOK AT THAT POSSIBILITY. && .LONG TERM (SAT NIGHT THROUGH THURS)... A WARMING TREND FOLLOWS THAT WILL LAST THRU MUCH OF THE THE WEEK. XPC GNLY DRY CONDS ALTHOUGH NEW GFS DID BRING A SHORT WAVE THRU THE AREA ON WEDNESDAY ALONG WITH A CHC OF TSTMS. FAVORED EMCWF HERE WITH IS DRIER WITH A LESS DVLPD SFC LOW TO OUR WEST AND KEPT POPS IN LOW CHC CAT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ SHORT TERM...OUDEMAN LONG TERM...TK AVIATION...MRD oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CLEVELAND OHIO 140 AM EDT FRI APR 7 2006 .AVIATION(06Z-06Z)... SIGNIFICANT AVIATION FORECAST ISSUES OVER THE NEXT 24 HOURS. LATEST SURFACE ANALYSIS SHOWS THE WARM FRONT STILL FROM MO THRU SRN IL INTO WRN KY. THE RUC AND THE NAM ARE VERY INSISTANT IN DRIVING THE FRONT NORTHEASTWARN OVER THE NEXT 6 HRS...WITH IT BEING POSITIONED FROM NRN INDIANA THRU CENTRAL OH BY 12Z. MEANWHILE...LOW PRES DEVELOPS AT THE TRIPLE POINT OVR NRN IN BY 12Z WHICH HELPS TO STALL THE FRONT OVR NRN OH UNTIL THE LOW PASSES EAST AND ALLOWS THE FRONT TO SHIFT SOUTH. PCPN IS CURRENTLY SPREADING INTO THE SWRN FORECAST AREA. EXPECT THIS PCPN TO SLOWLY SPREAD E-NE OVERNIGHT AS THE WARM FRONT MOVES NE. BY 12Z...NEARLY THE WHOLE FORECAST AREA WILL HAVE PCPN...BUT IT WILL TAKE AWHILE TO START ESPECIALLY AT ERI AND YNG DUE TO THE VERY DRY LOW LVL AIRMASS. EVENTUALLY...ALL SITES SHOULD DROP TO IFR. LIFR IS NOT OUT OF THE QUESTION IN THE HEAVIEST SHOWERS BUT CURRENTLY NO UPSTREAM SITES ARE REPORTING LIFR SO I HAVE OPTED TO LEAVE OUT OF THE FCST ATTM. NO THUNDER REPORTED EITHER AND WITH LACK OF ANY ELEVATED OR SFC INSTABILITY OVERNIGHT...HAVE OPTED TO REMOVE THUNDER FROM THE TAFS THRU 14Z. THE MODELS ARE IN GOOD AGREEMENT IN SHOWING THE FRONT HANGING UP JUST SOUTH OF THE LAKE ERIE SHORELINE WHICH MAKES SENSE GIVEN THE COLD LAKE. THIS WILL ALLOW FOR THE SRN PART OF THE FORECAST AREA TO SEE SOME DRY AIR AFT 14Z WHICH MAY ALLOW THE CIGS AT THE SOUTHERN SITES TO RISE TO TO MVFR. IN FACT...IT WOULD NOT BE TOTALLY SURPRISING TO ME IF THE SOUTHERN SITES SEE VFR CONDITIONS FRI MRNG AS THE WARM FRONT STAYS N OF THE AREA...ESPECIALLY SINCE SITES S OF THE WARM FRONT ARE VFR ATTM. HOWEVER...THIS PARTIAL CLEARING WILL ALSO SERVE TO DESTABILIZE THE ATMOSPHERE S OF THE FRONT FRI AFTN WHICH SHOULD HELP A LINE OF STORMS TO DEVELOP. BEST CHANCE FOR STORMS WILL BE GENERALLY ALONG AND SOUTH OF US224. COULD SEE SOME ELEVATED STORMS N OF THE WARM FRONT WITH THE NAM SHOWING ELEVATED CAPE VALUES AROUND 1000 J/KG AT KCLE AND KTOL. HOWEVER...CONFIDENCE OF THIS IS A LITTLE TOO LOW TO INCLUDE TSRA AT TOL/CLE/ERI ATTM. IF THE NAM THERMODYNAMIC AND KINEMATIC PROFILES VERIFY SOUTH OVER THE SOUTHERN HALF OF THE FORECAST AREA...SEVERE STORMS ARE CERTAINLY POSSIBLE. IF THE SRN PART OF THE FORECAST AREA SEES CLEARING TODAY...GUSTY SWLY WINDS WILL ALSO BE AN ISSUE. BUFKIT SHOWS GUSTS 25-35KT IN THE WARM SECTOR LATER THIS MRNG INTO THIS AFTN. BEHIND THE FRONT...THERE SHOULD BE PLENTY OF LOW LVL STRATUS TO DEAL WITH THROUGH 06Z WITH IFR CONDITIONS. MAY BE SOME SNOW SHOWERS AFT 00Z AT TOL...BUT THEY SHOULD BE MINOR AND LATER FORECASTS CAN LOOK AT THAT POSSIBILITY. && .SHORT TERM UPDATE(OVERNIGHT)... CURRENT FORECAST LOOKING ON TARGET WITH PRECIP BEGINNING TO DEVELOP ACROSS NORTHERN INDIANA AND WESTERN OHIO. TEMPERATURES THIS EVENING HAVE NOT MOVE MUCH FOLLOWING SUNSET...TEMPS STILL WITHIN A FEW DEGREES OF THE 60 DEGREE MARK AT TOLEDO AND STILL IN THE MID 50S NEAR CLEVELAND. WITH DEWPOINTS IN THE LOWER 30S...DO THINK THAT TEMPS WILL FALL OFF JUST A BIT ONCE THE RAIN BEGINS BUT DID MAKE A FEW MINOR CHANGES...MAINLY RE-WORDED TO SAY LOWS AROUND 50. OTHERWISE FORECAST IN GOOD SHAPE. && .AVIATION(00Z-00Z)... DEEP LOW PRES OVER CENTRAL PLAINS WITH WARM FRONT TO KY. WARM FRONT WILL LIFT N CLOSE TO SOUTHERN PORTION OF THE FORECAST AREA BY FRIDAY MORNING. HIGH VFR CONDITION TO START OUT THE FORECAST. WILL SPREAD RAIN ACROSS THE AREAS FROM SW TO NE STARTING AROUND MIDNIGHT...GRADUALLY LOWERING CIGS AND VSBYS TO IFR FEW HOURS AFTER RAIN BEGINS. THEN HOLD ONTO IFR UNTIL FEW HOURS AFTER FRONT SAGS LITTLE TO SE OF THE AREA AS A WAVE MOVES ALONG THE FRONT TOMORROW. WARM FRONT AND BEST INSTABILITY SHOULD REMAIN S OF THE AREA...BUT TSTMS POSSIBLE JUST NORTH OF THE WARM FRONT WITH FAIRLY STG 50KT 8H JET. && .SHORT TERM(TNGT-SAT)... SHOWERS AND THUNDERSTORMS CONTINUE IN OVERRUNNING ENVIRONMENT ACRS IL AND IND THIS AFTN WHILE BLOWOFF CLOUDS SPILL INTO NRN OH. LOTS OF FILTERED SS ACRS CWA THIS AFTN THOUGH. THIS OF COURSE WILL FILL IN THIS EVG AS WARM FRONT LIFTS OUT OF THE CNTRL PLAINS TWRD THE AREA. FOR TDA WL CONT WITH FCST OF SHOWERS AND THUNDERSTORMS OVERTAKING THE AREA FM THE SE OVERNIGHT. WILL WORD THE FCST AS PCPN DEVELOPING WEST AND WILL PLACE TIMING ACRS THE CNTRL AND ERN ZONES FOR DEVELOPING AROUND MIDNIGHT OR AFTER MIDNIGHT. XPC PRECIP TO REACH INTO NWRN PA LATE TNGT...PSBLY 3 TO 5 AM. QPF WILL LKLY BE IN THE 1 TO 3 INCH RANGE FOR THE EVENT BUT CRNT EXPECTATION IS THAT RAINFALL WILL NOT BCM EXCESSIVE ACRS THE BULK OF THE AREA. BEST CHC OF EXCESSIVE RAINFALL THRU FRIDAY EVG INDICATED BY HPC IS IN THE FAR SERN COUNTIES. FOR FRIDAY NAM12 ACTUALLY TAKES THE WARM FRONT ONTO THE LAKE FROM CLE EAST BASED ON BNDRY LYR WINDS BUT WARM FRONT DONT REALLY LAKE TO GO INTO THE LAKE THIS TIME OF YEAR SO BLV NAM15Z POSITION PROBABLY REPRESENTS THE NORTHWARD PROGRESSION OF THE BNDRY. THIS POSITION IS A LINE FM NR ERI TO CLE TO FDY LINE. STG FRONTOGENESIS SHOWN ACRS THE AREA FRIDAY WITH NLY/NELY FLOW TO OUR NORTH AND SWLY FLOW TO OUR SOUTH CREATING QUITE A SHARP THERMAL BOUNDRY WITH LOWER/MID 40S VS UPPER 60S NORTH TO SOUTH. WL CONT WITH CAT POPS FRIDAY. LATE FRIDAY MORNING/FRIDAY AFTERNOON THE FRONTAL SYSTEM ACRS THE AREA TURNS COLD AND PROGRESSES SOUTH ACRS THE AREA. EVENTUALLY DRAGGING MSTR SOUTH OF THE AREA TWRDS MORNING SAT. NAM12 CONTINUES TO INDICATE A TRANSITION TO SNOW FRIDAY NIGHT BEFORE PCPN ENDS SO WL CONT TREND IN THE FCST. UPPER TROF CONTINUES TO EXTEND OVER THE OH VLY SATURDAY AS COLD ADVN DROP 850MB TEMPS TO -8C OR SO DURG THE AFTN. KEPT SCT/BKN CLOUDS IN FOR THE NE AND N-CNTRL COUNTIES ALONG WITH THE PSBLITY OF FLURRIES BUT AMS REALLY IS VERY DRY AND INVN FCST TO BE QUITE LOW SO KEPT POPS LOW. && .LONG TERM (SAT NIGHT THROUGH THURS)... A WARMING TREND FOLLOWS THAT WILL LAST THRU MUCH OF THE THE WEEK. XPC GNLY DRY CONDS ALTHOUGH NEW GFS DID BRING A SHORT WAVE THRU THE AREA ON WEDNESDAY ALONG WITH A CHC OF TSTMS. FAVORED EMCWF HERE WITH IS DRIER WITH A LESS DVLPD SFC LOW TO OUR WEST AND KEPT POPS IN LOW CHC CAT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ SHORT TERM...LEINS/TK LONG TERM...TK AVIATION...MRD oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 331 AM CDT FRI APR 7 2006 .SHORT TERM... LOOKS LIKE ONE MORE DAY OF WARM AND WINDY CONDITIONS AS A LOW PRESSURE SYSTEM SLOWLY PULLS OUT OF THE PLAINS TODAY. SFC DRYLINE REMAINS STALLED ACROSS CENTRAL TX ALONG I-35 THIS MORNING. THE DRYLINE SHOULD MAKE SOME MORE EASTWARD PROGRESS TODAY AS SFC LOW PRESSURE IN S NEBRASKA PUSHES EAST. GFS/NAM 00Z INITIALIZATIONS SEEM NOT TO RESOLVE A DEEP ENOUGH LOW PRESSURE WHICH MAY RESULT IN A WEAKER PRESSURE GRADIENT AND WINDS OVER THE REGION. THE 06Z RUC SEEMS TO HAVE A BETTER HANDLE ON THIS WHICH SUPPORTS STRONGER WINDS IN THE 25-30KT RANGE LATE THIS MORNING. ALSO ANOTHER POTENT SHORTWAVE LOCATED OVER THE ROCKIES SHOULD DIVE INTO THE BOTTOM OF THE UPPER TROUGH OVER THE PLAINS. THIS SHORTWAVE MAY ALSO AID IN TIGHTENING THE PRESSURE GRADIENT AS WELL. FEEL PRESSURE GRADIENT WILL BE TIGHT ENOUGH TO SUPPORT STRONG WINDS SO WIND ADVISORY IS NEEDED FOR BIG COUNTRY...CONCHO VALLEY AND HEARTLAND. WITH DRY AIR IN PLACE...ALSO NEED RED FLAG WARNING FOR ALL AREAS. WINDS SHOULD EXCEED CRITERIA ESPECIALLY IN THE BIG COUNTRY AND RELATIVE HUMIDITY SHOULD BE BELOW 20 PERCENT. DESPITE THE POOR INITIALIZATION OF THE NAM...MODELS CONTINUE TO SUGGEST A STRONG COLD FRONT TO PUSH THROUGH FRI NIGHT WITH THE NAM THE COLDEST BETWEEN IT AND THE GFS. COLD ADVECTION SHOULD CONTINUE MOST OF SATURDAY WHICH WILL HOLD TEMPERATURES INTO THE UPPER 60S TO LOW 70S FOR MOST AREAS. LOW TEMPS WILL FALL BACK INTO THE 40S. UPPER LEVEL RIDGING SHOULD SPREAD OVER THE AREA THROUGH THE WEEKEND AS ANOTHER UPPER TROUGH DIGS OFF THE CALIFORNIA COAST. EARLY NEXT WEEK SFC HIGH PRESSURE SHOULD SHIFT EAST ALLOWING FOR SOME RETURN FLOW OFF THE GULF. WITH THE FRONT PUSHING WELL INTO THE GULF...MOISTURE SHOULD BE SLOW TO RETURN. .LONG TERM... EARLY NEXT WEEK GFS/ECMWF AGREE WITH ONE INITIAL SHORTWAVE TROUGH SCREAMING INTO THE PLAINS ON MONDAY WITH MEAN TROUGH SITUATED OFF THE CALIFORNIA COAST. MODELS SEEM QUITE CONTENT TO KEEP A MEAN TROUGH OFF THE CALIFORNIA COAST THROUGH MUCH OF NEXT WEEK WHICH KEEPS UPPER RIDGING OVER MUCH OF THE PLAINS. EXPECT TEMPERATURES TO REBOUND WELL INTO THE 80S FOR MAX TEMPS DURING THE WEEK. FORECASTED TEMPS ARE CLOSE TO GUIDANCE...BUT A PERHAPS A COUPLE OF DEGREES WARMER ON MAX TEMPS AS LOW LEVEL FLOW WILL MAINLY BE FROM THE SOUTH AND SOUTHWEST. THIS MAY ALLOW FOR ESTABLISHED ELEVATED MIX LAYER TO MIX DOWN RESULTING IN WARMER TEMPS THAN WHAT GUIDANCE SUGGESTS. WILL TRY NOT TO GET TOO CARRIED AWAY AS THERE IS GOOD AGREEMENT WITH GFS ENSEMBLE MOS NUMBERS...BUT STILL THINK TEMPS COULD WARM INTO THE UPPER 80S ESPECIALLY TOWARDS MID WEEK. RAIN CHANCES LOOK SLIM TO NONE AS ANY SHORTWAVE TROUGHS LOOK TO PUSH INTO THE CENTRAL PLAINS AND ATMOSPHERE SHOULD BE SUFFICIENTLY CAPPED BY ELEVATED MIXED LAYER WITH 700MB TEMPS RUNNING 8C-10C. THIS WILL ALSO BE AIDED BY THE FACT THAT MOISTURE WILL BE SLOW TO RETURN AND WILL BE SHALLOW AT BEST ESPECIALLY IN THE BEGINNING OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 83 45 66 47 / 0 0 0 0 SAN ANGELO 86 46 71 47 / 0 0 0 0 JUNCTION 90 45 73 46 / 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM FRIDAY TO 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO... CROCKETT...FISHER...HASKELL...IRION...JONES...KIMBLE...MASON... MCCULLOCH...MENARD...NOLAN...RUNNELS...SAN SABA...SCHLEICHER... SHACKELFORD...STERLING...SUTTON...TAYLOR...THROCKMORTON...AND TOM GREEN. WIND ADVISORY FROM 11 AM FRIDAY TO 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO...FISHER... HASKELL...IRION...JONES...MCCULLOCH...NOLAN...RUNNELS...SAN SABA...SHACKELFORD...STERLING...TAYLOR...THROCKMORTON...AND TOM GREEN. && $$ 23/10 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1200 PM EDT FRI APR 7 2006 UPDATE...SURFACE/RUC ANALYSIS AND IR/VIS SAT IMAGERY SHOW POLAR FRONT HAS REACHED APPROX SAGINAW BAY TO SOUTHWEST LOWER MICHIGAN...AND THE EDGE OF THE CLOUD COVER EXTENDING FROM NORTHERN LAKE HURON...THROUGH ALPENA AND TVC...AND WESTWARD TO NEAR GREEN BAY. RADAR IS SHOWING NORTHERN EXTENT OF RAIN SHOWERS FROM OSCODA TO LUDINGTON ACROSS NORTHERN LOWER WITH ONLY ISOLATED ACTIVITY NORTH OF THIS LINE TO ABOUT M-32. WITH MORE SHOWER ACTIVITY THROUGH CENTRAL WISCONSIN...THESE SHOWERS HAVE BEEN PROGRESSING SLOWLY NORTHWARD WITH TIME...AND WITH THE AREA OF FGEN/UPPER LEVEL DIV/AND 700-500MB Q-VECTOR CONVERGENCE... HAVE INCREASED POPS TO DEFINITE ALONG AND SOUTH OF M-55 WITH ONLY A CHANCE OF SHOWERS NORTH TO M-72. HAVE ALSO LEFT A CHANCE OF RAIN/SNOW SHOWERS FROM 22Z THROUGH 04Z THIS AFTERNOON/EVENING AS TEMPERATURES FALL...AND PRECIP MAY LINGER. MPC && .PREV DISCUSSION ISSUED AT 347 AM EDT THU APR 7 2005 CURRENT SPLIT FLOW PATTERN ACROSS CENTRAL NORTH AMERICA WILL CONSOLIDATE INTO A FULL LATITUDE TROUGH MOVING ACROSS THE EASTERN THIRD OF THE COUNTRY THIS WEEKEND...A COMBINATION OF NORTHERN STREAM UPPER LOW SPINNING SOUTH OUT OF ONTARIO...AND SOUTHERN STREAM SHORT WAVE ENERGY ACROSS THE CENTRAL PLAINS. PATTERN CONTINUES TO BE PROGRESSIVE...WITH THIS TROUGH SWEEPING OFF THE EAST COAST SUNDAY...WITH RISING HEIGHTS ACROSS THE GREAT LAKES IN ITS WAKE. FIRST THINGS FIRST...MIDNIGHT SURFACE ANALYSIS SHOWS A COLD FRONT ASSOCIATED WITH NORTHERN STREAM HEIGHT FALLS LYING ACROSS UPPER MI. THIS BOUNDARY SLIDES SOUTH TODAY AS POLAR HIGH PRESSURE RIDGES IN FROM THE NORTHWEST...AND BRINGS ANOTHER SHOT OF COOLER AIR INTO THE STATE. THIS HIGH THEN SETTLES IN FOR THE LATTER HALF OF THE WEEKEND...WITH WARM ADVECTION PATTERN GETTING RE-ESTABLISHED SUNDAY. SO FORECAST ISSUES TODAY DEAL WITH SHOWERS CURRENTLY ONGOING ACROSS NORTHERN LOWER MICHIGAN...THEN LAKE INDUCED CLOUD COVER/PRECIP ISSUES TONIGHT INTO SATURDAY AS 850MB TEMPERATURES DROP BACK TOWARD -10C. TODAY/TONIGHT...MID LEVEL INSTABILITY AND RRQ FORCING FROM JET STREAK NORTHEAST OF LAKE SUPERIOR TOUCHED OFF A NARROW BAND OF SHOWERS LAST EVENING BETWEEN M-68/M-32...WHICH HAS PERSISTED INTO THE EARLY MORNING HOURS. RADAR TRENDS SUGGEST A DIMINISHING TREND...SO WILL WAIT AND SEE HOW THINGS ARE SHAPING UP PRIOR TO PRESS TIME BEFORE DECIDING HOW TO HANDLE THIS. MEANWHILE...MORE EXTENSIVE AREA OF SHOWERS SPREADING OUT OF EASTERN WI AND TOWARD WESTERN LOWER MI...NORTHERN EXTENT REACHES UP TO M-72. AS NORTHERN STREAM SHORT WAVE DROPS IN FROM THE NORTHEAST THIS MORNING...MID LEVEL FLOW EVENTUALLY SHIFTS FROM WEST TO NORTHWEST...WHICH IN TURN SHOULD PUSH NORTHERN EDGE OF PRECIPITATION SHIELD SOUTH. BUT IN THE MEANTIME...LOOKS LIKE RAIN IS A GOOD BET THIS MORNING ALONG/SOUTH OF M-55 AND WILL RAISE POPS ALONG THAT CORRIDOR ACCORDINGLY...WITH CHANCE POPS TO M-72 THIS MORNING. WILL TRY AND PUSH PRECIPITATION OUT OF SOUTHERN PORTION OF FORECAST AREA BY AFTERNOON...IF IT DOES LINGER MAY BE DEALING WITH A MIX OR CHANGE TO SNOW BEFORE ENDING. WITH DRIER AIR COMING IN FROM THE NORTH DO EXPECT TO SEE SOME SUNSHINE BREAK OUT AS THE DAY WEARS ON. FOR TONIGHT NORTHERLY FLOW WILL PREVAIL WITH A SHALLOW OVER WATER CBL WITH 850MB TEMPERATURES HOVERING AROUND -10C. SO VARIABLE AMOUNTS OF CLOUD COVER ANTICIPATED...WITH MORE CLOUDS NEAR THE LAKES IN AREAS FAVORED BY NORTHERLY FLOW ALONG WITH PERHAPS A FEW FLURRIES. SATURDAY...OTHER THAN SOME NUISANCE CLOUDS/FLURRIES EARLY ON... SATURDAY OVERALL LOOKS TO BE A QUIET DAY AS HIGH PRESSURE SLIDES IN FROM THE WEST. EXPECTING SOME MORE CLEARING SATURDAY NIGHT...THOUGH PERHAPS SOME WARM ADVECTION MID CLOUD SPILLING INTO THE AREA OVERNIGHT. MARINE...WINDS WILL INCREASE BEHIND COLD FRONTAL PASSAGE TODAY AS GRADIENT TIGHTENS UP AND COLD ADVECTION MIXES DOWN SOME MOMENTUM. SMALL CRAFT ADVISORIES ALREADY UP AND LOOKS JUST FINE. COULD SEE SOME GALE FORCE GUSTS IN COASTAL CONVERGENCE AREAS SOUTH OF PRESQUE ISLE LIGHT ON THE LAKE HURON SIDE...AND PERHAPS WITH WINDS FUNNELING THROUGH THE MANITOU PASSAGE. WINDS WILL SUBSIDE TONIGHT...AND EXPECTING WINDS TO REMAIN BELOW ADVISORY CRITERIA THROUGH THE REMAINDER OF THE WEEKEND. JPB && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1103 AM EDT FRI APR 7 2006 .UPDATED... I WILL SHORTLY PUT OUT A QUICK UPDATE TO SUGGEST RAIN WILL MIX WITH SNOW OVER THE NRN 1/3 OF THE CWA AFTER 18Z. THIS IS BASED ON THE ADVECTION OF DRIER AIR IN FROM THE NORTH AND THE PERSISTENCE OF THE FGEN PCPN BAND THROUGH A GOOD PART OF THE AFTERNOON. RUC 1300 1000/850MB THICKNESS LINE NEAR RQB BY 18Z AND GRR BY 21Z. THIS IS STRONG ENOUGH COLD ADVECTION THAT AS LONG AS THERE IS SIGNIFICANT PCPN FALLING IT SHOULD BE CHANGING TO SNOW BY THEN. WATER VAPOR... IR IMAGES AND RADAR LOOPS ALL SUGGEST THE FGEN RAIN BAND WILL CONTINUE FOR SEVERAL MORE HOURS. THIS IS MORE IN LINE WITH THE NEW NAM AND RUC THAN THE 00Z OR 06Z GFS. MOST OF THE PRECIPITATION THIS AFTERNOON WILL BE FROM 30 MILE SOUTH OF I-96 TO NEAR ROUTE 10. I EXPECT THE THUNDERSTORMS OVER THE SOUTHERN EDGE OF THE PCPN FIELD TO END BY EARLY AFTERNOON AS THE FGEN FORCING STARTS TO WEAKEN. IT IS CURIOUS TO NOTE BOTH THE RUC AND NAM SHOW THE LAST AREA TO SEE PRECIPITATION IS BE NORTH OF INTERSTATE 96 EARLY THIS EVENING. GIVEN WHAT I SEE ON SATELLITE AND RADAR LOOPS THIS DOES MAKE SENSE. WHICH BRINGS ME BACK TO THE SNOW ISSUE. IF THAT BAND DOES STAY THERE TILL NEAR 00Z THERE COULD BE SOME LIGHT ACCUMULATIONS. WE WILL HAVE TO MONITOR THAT. && .GRR WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY NEARSHORE WATERS ST. JOSEPH TO MANISTEE THROUGH TONIGHT. && $$ WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1055 AM EDT FRI APR 7 2006 .UPDATE... CURRENT TEMPERATURES GENERALLY BTWN UPR 20S OVR HIGHER TERRAIN NEAR LK SUPERIOR TO THE UPR 30S OVR SCNTRL AREAS AND LOCATIONS NEAR LK MI. COLD AIR ADVECTION CONTINUES THROUGH DAY AS H95-H85 THERMAL TROUGHS SETTLE OVR THE REGION IN WAKE OF SHORTWAVE SLIDING INTO QUEBEC. VWP SHOWS WINDS WITHIN LOWEST 3KFT AGL UP TO 25 KT WHILE OVR LK SUPERIOR A FEW GALES HAVE BEEN OBSERVED ON W HALF. THUS FAR...JUST A FEW LIGHT FLURRIES OVR THE UPSLOPE HIGHER TERRAIN AREAS OF BARAGA INTO MARQUETTE COUNTIES. WIDESPREAD AREA OF STRATOCUMULUS CLOUDS HAVE DEVELOPED OVR MUCH OF N HALF OF CWA. TWEAKED SKY COVER TO LINGER BKN CLOUDS LONGER THROUGH AFTN AND ALSO ADJUSTED TEMPS SLIGHTLY TO SHOW MORE WARMING OVR SCNTRL AREAS (NEAR 40) AND COOLER TEMPS OVR HIGHER TERRAIN OF NW/NCNTRL (UPR 20S/NEAR 30). TEMPS MAY TRY TO RISE SLIGHTLY BY LATE AFTN IF CLOUDS BREAK DUE TO HIGH SUN ANGLE. OTHERWISE...MOST SPOTS NEAR LK SUPERIOR SHOULD REMAIN ANCHORED IN THE UPR 20S AND LWR 30S. WHAT A DIFFERENCE COMPARED TO YDY AS AFTN TEMPS YDY IN MOST AREAS TOPPED OUT IN THE MID 50S TO LWR 60S. && .PREV DISCUSSION (ISSUED AT 332 AM EDT)... THE MAIN CONCERNS WITH THIS FORECAST PACKAGE ARE WITH THE WINDS TODAY AND THE CHANCE OF PRECIPITATION TONIGHT. WATER VAPOR IMAGERY AND RUC/NAM SHOWING DEEP LOWS OVER NORTHEAST KANSAS AND OVER SOUTHERN JAMES BAY...WITH A RIDGE SEPARATING THESE EXTENDING FROM THE OHIO RIVER VALLEY THROUGH WISCONSIN...INTO NORTH DAKOTA. ANOTHER RIDGE EXTENDS FROM THE SOUTHERN ROCKIES THROUGH MONTANA INTO THE CANADIAN PRAIRIES. SURFACE ANALYSIS SHOWING A LOW OVER SOUTHEAST NEBRASKA. A FRONTAL SYSTEM EXTENDS EAST FROM THIS LOW THROUGH THE LOWER GREAT LAKES INTO SOUTHWEST QUEBEC. A FRONT ALSO RUNS WEST FROM THE NEBRASKA LOW THROUGH WYOMING AND WESTERN MONTANA. A BROAD RIDGE IS OVER CENTRAL CANADA. THE JAMES BAY MID LEVEL LOW WILL SHIFT INTO SOUTHWEST QUEBEC... WHILE THE LOW OVER NORTH KANSAS SLIDES INTO OKLAHOMA TODAY. A WEAK SHORTWAVE WRAPPING AROUND THE JAMES BAY LOW WILL SWEEP THROUGH THE FORECAST AREA. SOUNDINGS SHOWING AN INVERSION AT AROUND 3.5K FEET. CONDITIONS ARE VERY DRY ABOVE THE INVERSION BUT RATHER HIGH RH JUST BELOW THIS LEVEL. THEREFORE...EXPECT CONSIDERABLE LOW CLOUDS. THE FORECAST MODELS SHOW THAT IT WILL CONTINUE TO BE FAIRLY DRY AT THE SURFACE. THEREFORE...THE SNOW WILL HAVE TO SATURATE OUT THE LOW LEVELS BEFORE GETTING TO THE SURFACE. SURFACE TO 900MB LAPSE RATE WILL BE ON THE ORDER OF 8.5-9.5C/KM. STRONGEST 900MB OMEGA WILL BE NORTH OF M-28 FROM KIWD TO KSAW. I WILL BE LOOKING FOR A CHANCE OF SOME FLURRIES THERE TODAY. A WARMING AT THE SURFACE WILL REDUCE CHANCE OF PRECIPITATION IN THE AFTERNOON...AS THE RH LOWERS THROUGH THE DAY. THE LOW LEVEL INVERSION WILL ALLOW SOME OF WINDS AT 925MB TO MIX TO SURFACE ESPECIALLY OVER LAKE SUPERIOR. SO WILL KEEP SOME BREEZY GUSTY CONDITIONS THROUGH THE DAY. ANOTHER SHORTWAVE ROTATING THROUGH THE BASE OF THE QUEBEC LOW WILL SWEEP THROUGH THE FORECAST AREA TONIGHT. THE CANADIAN SURFACE WILL SLIDE OVER THE NORTHERN AND CENTRAL PLAINS. THE LAYER AROUND 900MB WILL REMAIN FAIRLY MOIST WHICH WILL HELP IN PRODUCING SOME PRECIPITATION. MODELS SOUNDINGS CONTINUE TO SHOW NEARLY DRY AT THE SURFACE...AND SURFACE-900MB LAPSE RATE AROUND 8.5C/KM. TEMPERATURES WILL BE WELL BELOW FREEZING...THEREFORE...LOOKING FOR A CHANCE OF SOME LIGHT SNOW OR FLURRIES OVERNIGHT. TRAJECTORY FORECAST AND GUIDANCE INDICATE THAT THE OVERNIGHT LOWS SHOULD DIP INTO THE MID TO LOW 20S WHICH WITH THE EXPECTED WINDS AND CLOUDY CONDITIONS SOUND REASONABLE. ANOTHER VERY WEAK SHORTWAVE WILL SWEEP THROUGH THE AREA ON SATURDAY. THE SURFACE RIDGE WILL EXPAND TO BLANKET THE UPPER GREAT LAKES ON SATURDAY AND SLIDE INTO THE OHIO RIVER VALLEY ON SUNDAY. THE AIR MASS WILL BE VERY STABLE AND DRY WHICH WILL KEEP FAIR CONDITIONS THROUGH THE WEEKEND. THE MID LEVEL RIDGE WILL WEAKEN AS IT SLIDE OVER THE UPPER GREAT LAKES ON SUNDAY NIGHT. A WEAK SHORTWAVE SHIFTING THROUGH THIS RIDGE WILL BE OVER THE FORECAST AREA SUNDAY NIGHT. A LOW WILL DEVELOP OVER THE NORTHERN PLAINS WITH A COLD FRONT. A SOUTHWEST FLOW WILL OCCUR ON THE BACKSIDE OF THE RIDGE DRAWING WARMER MOIST AIR FROM THE GULF INTO THE AREA. THE NORTHERN PLAINS LOW WILL MOVE INTO THE FORECAST AREA LATE ON TUESDAY AND BRING AN INCREASE CHANCE OF SHOWERS TO THE REGION. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JLA PREV DISCUSSION...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1030 AM EDT FRI APR 7 2006 .SHORT TERM /TODAY/...MAIN FORECAST ISSUES FOR TODAY WILL BE CONTINUED DRY WEATHER AND GUSTY WINDS. LATEST RUC MODEL RUN SHOWS 925 MB WINDS INCREASING TO 30 KNOTS IN THE NORTHERN ZONES AND 25 KNOTS SOUTHERN ZONES TODAY. ANALYSIS OF MODEL SOUNDINGS SUGGEST A DEEP MIXED LAYER DURING THE WARM AFTERNOON THAT WOULD BE CAPABLE OF BRINGING SOME OF THESE HIGHER WINDS TO THE SURFACE. ADDITIONALLY...THE SURFACE PRESSURE GRADIENT WILL BE TIGHTENING BETWEEN A LARGE CYCLONE TO OUR WEST AND NORTH WITH HIGH PRESSURE OVER THE ATLANTIC. CURRENT FORECAST LOOKS ON TRACK WITH MENTION OF GUSTS UP TO 35 KNOTS DURING THE AFTERNOON...AS WELL AS CONTINUED MODERATE SOUTHWEST WINDS OVERNIGHT. HIGHS TODAY WILL RISE INTO THE LOWER TO MID 80S UNDER PARTLY CLOUDY SKIES...EXCEPT 70S ALONG THE COAST WHERE THE SEABREEZE WILL BRING COOLER NEARSHORE OCEAN AIR TOWARD THE BEACHES. && .FIRE WEATHER...RH VALUES WILL BE NEAR CRITICAL AWAY FROM THE COAST THIS AFTERNOON. THE CONTINUED LOW HUMIDITIES...GUSTY WINDS ABOVE CRITICAL THRESHOLDS DUE TO AFTERNOON MIXING OF WINDS ALOFT...AND DRY FUELS HAS NECESSITATED THE ISSUANCE OF A RED FLAG WARNING FOR SC AND GA ZONES THIS AFTERNOON THROUGH THE EVENING. && .MARINE...SOUTH TO SOUTHWEST WINDS EXPECTED TO INCREASE THIS AFTERNOON AND EVENING AS THE PRESSURE GRADIENT ACROSS THE WATERS TIGHTENS BETWEEN HIGH PRESSURE OVER THE ATLANTIC AND A STRONG STORM SYSTEM TO THE NORTH AND WEST. SCA IN EFFECT BEGINNING TONIGHT FOR OFFSHORE GA WATERS DUE TO BUILDING SEAS UNDER A SUFFICIENT SOUTHERLY FETCH. SCA ALSO IN EFFECT FOR CHARLESTON HARBOR TODAY THROUGH THIS EVENING. GUSTY WINDS THIS AFTERNOON IN THE HARBOR WILL BE THE COMBINED EFFECT OF THE AFTERNOON SEABREEZE AND MIXING OF STRONGER WINDS ALOFT. CURRENT COASTAL WATERS FORECAST ON TRACK. NO CHANGES FOR THE MORNING ISSUANCE. && .AVIATION...GUSTY SOUTHWEST TO SOUTH WINDS LIKELY DURING THE EARLY AFTERNOON DUE TO INCREASED MIXING OF HIGHER WINDS ALOFT. WINDS WILL BEGIN TO SUBSIDE DURING THE EVENING...HOWEVER WINDS WILL QUICKLY INCREASE ABOVE THE SURFACE. LLWS INCLUDED IN THE TAFS AT BOTH TERMINALS AFTER 02Z TONIGHT. SKIES WILL BE VFR DURING THE PERIOD UNDER SCATTERED HIGH CLOUDS. && .LAKE WINDS...A DEEP MIXING LAYER TODAY WILL ALLOW STRONGER WINDS ALOFT TO MIX DOWN TO THE SURFACE...ESPECIALLY NEAR THE LAKE SHORE. THUS...A LAKE WIND ADVISORY HAS BEEN ISSUED FOR LAKE MOULTRIE THROUGH THIS EVENING. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...RED FLAG WARNING NOON UNTIL 7 PM FOR GAZ087-088-099>101-114>116- 118-137-138-140. SC...RED FLAG WARNING NOON UNTIL 7 PM FOR SCZ040-042>045-047. LAKE WIND ADVISORY FOR LAKE MOULTRIE UNTIL 10 PM SCZ045. MARINE...SMALL CRAFT ADVISORY FOR AMZ330-374. && $$ WMS sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 631 AM CDT FRI APR 7 2006 .AVIATION... EXPECT VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR THE NEXT 24 HOURS. HOWEVER...STRONG WEST TO NORTHWEST WINDS AROUND 20 KNOTS WITH GUSTS TO 35 KNOTS WILL DOMINATE WEST CENTRAL TEXAS BEGINNING LATE THIS MORNING AND CONTINUING UNTIL AROUND SUNSET THIS EVENING. LIKE YESTERDAY...BLOWING DUST MAY OCCASIONALLY REDUCE THE VISIBILITY IN SOME LOCATIONS TO AROUND 2 MILES...MAINLY ALONG AND NORTH OF INTERSTATE 20 THIS AFTERNOON. THIS EVENING...A STRONG COLD FRONT WILL PUSH SOUTH ACROSS WEST CENTRAL TEXAS AND SHIFT WINDS TO THE NORTH. AFTER MIDNIGHT TONIGHT...EXPECT NORTH WINDS AROUND 10 KNOTS ACROSS WEST CENTRAL TEXAS. && .PREV DISCUSSION... (ISSUED 331 AM CDT FRI APR 7 2006) SHORT TERM... LOOKS LIKE ONE MORE DAY OF WARM AND WINDY CONDITIONS AS A LOW PRESSURE SYSTEM SLOWLY PULLS OUT OF THE PLAINS TODAY. SFC DRYLINE REMAINS STALLED ACROSS CENTRAL TX ALONG I-35 THIS MORNING. THE DRYLINE SHOULD MAKE SOME MORE EASTWARD PROGRESS TODAY AS SFC LOW PRESSURE IN S NEBRASKA PUSHES EAST. GFS/NAM 00Z INITIALIZATIONS SEEM NOT TO RESOLVE A DEEP ENOUGH LOW PRESSURE WHICH MAY RESULT IN A WEAKER PRESSURE GRADIENT AND WINDS OVER THE REGION. THE 06Z RUC SEEMS TO HAVE A BETTER HANDLE ON THIS WHICH SUPPORTS STRONGER WINDS IN THE 25-30KT RANGE LATE THIS MORNING. ALSO ANOTHER POTENT SHORTWAVE LOCATED OVER THE ROCKIES SHOULD DIVE INTO THE BOTTOM OF THE UPPER TROUGH OVER THE PLAINS. THIS SHORTWAVE MAY ALSO AID IN TIGHTENING THE PRESSURE GRADIENT AS WELL. FEEL PRESSURE GRADIENT WILL BE TIGHT ENOUGH TO SUPPORT STRONG WINDS SO WIND ADVISORY IS NEEDED FOR BIG COUNTRY...CONCHO VALLEY AND HEARTLAND. WITH DRY AIR IN PLACE...ALSO NEED RED FLAG WARNING FOR ALL AREAS. WINDS SHOULD EXCEED CRITERIA ESPECIALLY IN THE BIG COUNTRY AND RELATIVE HUMIDITY SHOULD BE BELOW 20 PERCENT. DESPITE THE POOR INITIALIZATION OF THE NAM...MODELS CONTINUE TO SUGGEST A STRONG COLD FRONT TO PUSH THROUGH FRI NIGHT WITH THE NAM THE COLDEST BETWEEN IT AND THE GFS. COLD ADVECTION SHOULD CONTINUE MOST OF SATURDAY WHICH WILL HOLD TEMPERATURES INTO THE UPPER 60S TO LOW 70S FOR MOST AREAS. LOW TEMPS WILL FALL BACK INTO THE 40S. UPPER LEVEL RIDGING SHOULD SPREAD OVER THE AREA THROUGH THE WEEKEND AS ANOTHER UPPER TROUGH DIGS OFF THE CALIFORNIA COAST. EARLY NEXT WEEK SFC HIGH PRESSURE SHOULD SHIFT EAST ALLOWING FOR SOME RETURN FLOW OFF THE GULF. WITH THE FRONT PUSHING WELL INTO THE GULF...MOISTURE SHOULD BE SLOW TO RETURN. LONG TERM... EARLY NEXT WEEK GFS/ECMWF AGREE WITH ONE INITIAL SHORTWAVE TROUGH SCREAMING INTO THE PLAINS ON MONDAY WITH MEAN TROUGH SITUATED OFF THE CALIFORNIA COAST. MODELS SEEM QUITE CONTENT TO KEEP A MEAN TROUGH OFF THE CALIFORNIA COAST THROUGH MUCH OF NEXT WEEK WHICH KEEPS UPPER RIDGING OVER MUCH OF THE PLAINS. EXPECT TEMPERATURES TO REBOUND WELL INTO THE 80S FOR MAX TEMPS DURING THE WEEK. FORECASTED TEMPS ARE CLOSE TO GUIDANCE...BUT A PERHAPS A COUPLE OF DEGREES WARMER ON MAX TEMPS AS LOW LEVEL FLOW WILL MAINLY BE FROM THE SOUTH AND SOUTHWEST. THIS MAY ALLOW FOR ESTABLISHED ELEVATED MIX LAYER TO MIX DOWN RESULTING IN WARMER TEMPS THAN WHAT GUIDANCE SUGGESTS. WILL TRY NOT TO GET TOO CARRIED AWAY AS THERE IS GOOD AGREEMENT WITH GFS ENSEMBLE MOS NUMBERS...BUT STILL THINK TEMPS COULD WARM INTO THE UPPER 80S ESPECIALLY TOWARDS MID WEEK. RAIN CHANCES LOOK SLIM TO NONE AS ANY SHORTWAVE TROUGHS LOOK TO PUSH INTO THE CENTRAL PLAINS AND ATMOSPHERE SHOULD BE SUFFICIENTLY CAPPED BY ELEVATED MIXED LAYER WITH 700MB TEMPS RUNNING 8C-10C. THIS WILL ALSO BE AIDED BY THE FACT THAT MOISTURE WILL BE SLOW TO RETURN AND WILL BE SHALLOW AT BEST ESPECIALLY IN THE BEGINNING OF THE WEEK. && .SJT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM FRIDAY TO 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO... CROCKETT...FISHER...HASKELL...IRION...JONES...KIMBLE...MASON... MCCULLOCH...MENARD...NOLAN...RUNNELS...SAN SABA...SCHLEICHER... SHACKELFORD...STERLING...SUTTON...TAYLOR...THROCKMORTON...AND TOM GREEN. WIND ADVISORY FROM 11 AM FRIDAY TO 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO...FISHER... HASKELL...IRION...JONES...MCCULLOCH...NOLAN...RUNNELS...SAN SABA...SHACKELFORD...STERLING...TAYLOR...THROCKMORTON...AND TOM GREEN. && $$ 23/23/23 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1024 AM EDT FRI APR 7 2006 .SHORT TERM /REST OF TODAY/... LAST OF MORNING SHRA/TSRA POISED TO EXIT NE CORNER OF CWA. SOME WEAKENING HAS BEEN OCCURRING AS NOCTURNAL LOW LEVEL JET WEAKENS. CWA WILL ENJOY A BRIEF BREAK FROM PRECIPITATION UNTIL LATER THIS AFTERNOON. FOCUS NOW SHIFTS TO CONVECTION EXPECTED AFTER 21Z OR SO. LOOKING LIKE A BAND WILL BE FOCUSED ALONG APPROACHING FRONT...FED BY LOW LEVEL CONVERGENCE. THIS ZONE WILL BE BACK NEAR CMH AROUND 00Z...DROPPING TO NEAR A HTS/CKB LINE BY 03Z...AND APPROACHING BKW BY 06Z. ANOTHER POSSIBLE FOCUSING MECHANISM WILL BE BOUNDARY LAID DOWN BY CONVECTION THIS MORNING FROM CVG TO PKB. RUC SEEMS TO PICK UP ON THIS. THIS IS EVIDENT ON SURFACE OBS...WITH 55 DEGREES AT PKB AND 71 AT CRW AT 14Z. COULD SEE SOME EARLIER DEVELOPMENT HERE AS INSTABILITY BUILDS. FOR NOW...BETTING ON LATER BOUNDARY TO BE THE MAIN FOCUS...AND AS SUCH KEPT LATER POPS THE WAY THEY WERE. REDUCED POPS BEFORE 18Z AS IT WILL TAKE A FEW HOURS FOR INSTABILITY TO BUILD. UPPED HIGH TEMPS ACROSS SOUTHERN PART OF REGION...AND DROPPED THEMA BIT IN RAIN COOLED AREA. PLENTY TO MONITOR THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 422 AM EDT FRI APR 7 2006/ SHORT TERM /REST OF TODAY THROUGH TONIGHT/... WARM FRONT TO OUR NORTH IS EVIDENT ON SFC OBS DEWPOINT DISCONTINUITY. RADAR SHOWS LIGHT RAIN SHOWERS MOVING MAINLY EAST...MORE NUMEROUS ACROSS THE NORTHERN HALF OF WEST VIRGINIA AND SOUTHEAST OHIO. VERY ISOLATED THUNDERSTORMS COULD BE POSSIBLE AS THEY MOVE INTO SOUTHEAST OHIO...BUT WILL BE SHORT LIVED THIS MORNING. NAM AND LOCAL WRF MODELS SHOWING DESCENT MUCAPE OF NEAR 2500 J/KG... LOW LEVEL MOIST CONVERGENCE...AND LIFTED INDEX OF -4 C...SUGGEST POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND EVENING ACROSS SOUTHEAST OHIO...ACROSS NORTHERN WEST VIRGINIA AND ALONG THE OHIO RIVER IN WEST VIRGINIA. SPC HAS THIS AREA UNDER A SLIGHT RISK FOR SEVERE WEATHER TODAY AND TONIGHT. INCLUDED STRONG GUSTY WINDS AND SMALL HAIL WITH THUNDERSTORMS ACROSS THE WEST AND NORTH. SOUTHERLY WEAK FLOW WILL BECOME GENTLE FROM THE SOUTHWEST BY MID MORNING AND STRONG AND GUSTY FROM THE WEST SOUTHWEST THIS AFTERNOON. COLD FRONT IS EXPECTED TO MOVE THRU THE AREA AROUND 06Z TONIGHT. WARM TEMPERATURES TODAY WILL REACH THE MID TO UPPER 70S LOWLANDS...RANGING TO LOWER 60S OVER HIGHER TERRAIN IN THE NORTHERN MOUNTAINS. TWEAKED LOCAL MOS TEMPS FOR HIGHS TODAY...AND WENT CLOSE TO MAV NUMBERS FOR LOWS TONIGHT. LONG TERM /SATURDAY THROUGH THURSDAY/... HAVE SHRUNK THE LINE BETWEEN PRECIPITATION AND DRY WEATHER SATURDAY...AS IT CONTINUES TO BE EVIDENT THAT LITTLE SHOULD OCCUR BEHIND THE THIN LINE OF CONVECTION THAT WILL CROSS OVERNIGHT TONIGHT. OUR LARGE AREA OF LOW PRESSURE...WILL BE REPLACED BY A LARGE AREA OF HIGH PRESSURE ACROSS THE CENTRAL AND EASTERN U.S. THROUGH TUESDAY. THE SFC HIGH SHOULD BE OVERHEAD SUNDAY NIGHT INTO MONDAY MORNING. AS FOR THE CHANCE FOR PRECIPITATION THROUGH THE REMAINDER OF THE TIME PERIOD...DID NOT ADD ANYTHING TO OUR DRY PATTERN THAT WILL SET UP THROUGH AT LEAST TUESDAY. ANOTHER CHANGE WILL BE THE RETURN OF LIGHTER WINDS THAT WE ARE MORE USE TO...AS HIGH PRESSURE DOMINATES. NO EDITS WERE DONE TO THE FORECAST PAST TUESDAY. PREV DISCUSSION... /ISSUED 155 AM EDT FRI APR 7 2006/ AVIATION... LATEST SFC OBS SHOW DEWPOINT WARM FRONT ALREADY NORTH OF PKB AND EKN. RADAR SHOWS RAIN SHOWERS MOVING EAST NORTHEAST MAINLY ACROSS THE NORTHERN HALF OF THE AREA...TO AFFECT PKB...CKB...EKN ON AND OFF THRU AT LEAST 10Z. ADDITIONAL LIGHT SHOWERS COULD STILL AFFECT THE SOUTHERN SITES...CRW...HTS...AND BKW SO INCLUDE RAIN IN A TEMPO OVERNIGHT. VFR CONDITIONS FOR THE MOST PART WITH OCCASIONALLY MVFR/IFR VISIBILITIES AND CEILINGS WITHIN RAIN SHOWERS. COLD FRONT IS EXPECTED TO AFFECT THE AREA FROM WEST TO EAST AND BRING THUNDERSTORMS TO THE AREA TONIGHT AROUND 03-06Z SAT. WILL HAVE A CLOSER TIMING ON NEXT TAF ISSUANCE. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...CL wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 453 PM CDT FRI APR 7 2006 .DISCUSSION... FORECAST CONCERNS... WIND AND SHOWER TRENDS INTO THE EVENING... DEEP/NEARLY VERTICALLY STACKED LOW PRESSURE ACROSS EASTERN KANSAS WILL BEGIN TO FILL AS IT SLIDES SOUTHEAST INTO THE OZARKS TONIGHT. HOWEVER...STRONG LOW LEVEL PRESSURE GRADIENT WINDS WILL CONTINUE TO AFFECT AREAS ALONG AND WEST OF THE TURNPIKE INTO THE EVENING AND WE WILL EXTENDED WIND ADVISORY UNTIL 03Z (10 PM). SHOWERS WILL ALSO CONTINUE TO PINWHEEL AROUND THE MID/UPPER LEVEL CIRCULATION THOUGH GENERALLY WANING THRU THE EVENING HOURS. MODIFIED POINT SOUNDINGS AND RUC MESO ANALYSIS SUGGEST SOME WEAK INSTABILITY WILL EXIST ACROSS THE FLINT HILLS AND SOUTHEAST KANSAS UNTIL DARK...WITH 0-3KM CAPES OF 75-100 J/KG. PERIODS OF SURFACE HEATING MAY GIVE A LOCAL BOOST TO THESE VALUES...LEADING TO THE REMOTE POTENTIAL OF ISOLATED UPDRAFT ENHANCEMENT FOR A BRIEF STRONG STORM AND EVEN WEAK/BRIEF FUNNEL. ALREADY HAD ONE REPORT OF SOME ROTATION WITH A SHOWER SOUTHEAST OF WICHITA AREA EARLIER THIS AFTERNOON...AND NOT TOO UNCOMMON UNDER THIS TYPE OF UPPER LOW REGIME. OTHERWISE...THE CLOUDS AND PRECIP WILL DECREASE/DIMINISH RAPIDLY AFTER MIDNIGHT ALONG WITH THE WINDS FOR MORE TRANQUIL WEATHER BY MIDDAY SATURDAY. ONLY SLIGHT TWEAKS TO GOING FORECAST NEEDED. FAIR WEATHER WITH A STEADY MODERATING TREND EXPECTED INTO SUNDAY NIGHT AND MONDAY...AS UPPER RIDGE SLIDES EAST FROM THE ROCKIES ACROSS THE MIDWEST. AGAIN LITTLE CHANGE NEEDED TO GOING FORECAST TRENDS WITH MAXS WELL INTO THE 70S BY MONDAY AND SOUTH WINDS INTO THE WINDY CATEGORY. LITTLE CHANGE TO THE OUTER PERIODS AS WELL AND WILL CONTINUE MODEST CHANCE POPS FOR TUESDAY AS UPPER TROF EJECTS QUICKLY ACROSS THE PLAINS. BUILDING UPPER RIDGE THEREAFTER TO KEEP TEMPERATURES ON THE PLEASANTLY WARM SIDE...GENERALLY IN THE UPPER 70S TO AROUND 80 DEGREES FOR THE END OF THE WEEK. DARMOFAL && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 37 60 37 70 / 30 0 0 0 HUTCHINSON 35 60 37 71 / 20 0 0 0 NEWTON 36 59 36 69 / 30 0 0 0 ELDORADO 37 59 36 69 / 40 0 0 0 WINFIELD-KWLD 38 61 37 71 / 30 0 0 0 RUSSELL 31 58 37 72 / 10 0 0 0 GREAT BEND 32 59 38 72 / 10 0 0 0 SALINA 34 59 36 71 / 20 0 0 0 MCPHERSON 35 60 37 71 / 20 0 0 0 COFFEYVILLE 39 59 35 69 / 40 0 0 0 CHANUTE 37 57 35 68 / 40 0 0 0 IOLA 37 57 35 68 / 40 0 0 0 PARSONS-KPPF 39 59 35 69 / 40 0 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 10 PM FRIDAY FOR KSZ032-033-047>053-067>069- 082-083-091>093. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 348 PM CDT FRI APR 7 2006 .DISCUSSION... CLOUDS AND RAIN HAVE DEVELOPED OVER THE AREA UNDER THE UPPER LOW...WHICH HAS ROTATED BACK OVER THE STATE. EXPECT GENERALLY LESS THAN HALF AN INCH OF ACCUMULATIONS FROM THE PRECIPITATION AS AIR MASS IS PRETTY STABLE...PWS ARE LESS THAN AN INCH...AND SYSTEM MOVES OUT OF THE AREA THIS EVENING. WINDS WILL BE CONCERN AS SYSTEM SLIDES SOUTHWARD. AS THE SURFACE LOW MOVES INTO SOUTHEAST MO THIS EVENING...TIGHT GRADIENT BEHIND WILL SHIFT OVER THE FA GENERALLY BETWEEN 4PM AND 8PM. GRADIENT ALONE SUGGESTS SUSTAINED WINDS COULD REMAIN AT OR BELOW 30 MPH...BUT 850MB WINDS ON THE RUC MOVING AROUND THE UPPER TROF SHOW WINDS 45-50 MPH MAINLY WEST OF AN EMPORIA TO MARYSVILLE LINE. THINK THE PRECIP BAND MAY MIX SOME OF THESE DOWN AND BOOST SURFACE WINDS AND GUSTS FOR A FEW HOURS OUT WEST AND WILL THEREFORE HOIST A WIND ADVISORY FOR THESE LOCALES. PRECIP ENDS QUICKLY LATE EVENING...AND SHOULD GET TO CLEAR SKIES FOR SATURDAY ALTHOUGH TEMPERATURES PROBABLY WONT MAKE IT OUT OF THE UPPER 50S MOST AREAS. SFC HIGH PRESSURE RIDGE OVER THE CWA WILL BEGIN TO PULL EASTWARD INTO MO WITH LIGHT SOUTH/SOUTHEASTERLY FLOW ACROSS THE CWA AFTER MIDNIGHT. SOME FROST POTENTIAL IN FAVORED LOW LYING AREAS WITH THE CLEAR SKIES AND INITIAL VERY LIGHT WINDS...BUT SOME CONCERN ABOUT RETURN FLOW PRODUCING ENOUGH MIXING TO LIMIT FROST FORMATION LATER IN THE NIGHT. NEXT COUPLE OF SHIFTS WILL NEED TO REEVALUATE THE FROST POTENTIAL AND MAY NEED TO ADD TO THE GRIDS IF MIXING AND RETURN FLOW IS DELAYED. EITHER WAY...LOWS SATURDAY NIGHT IN THE MID 30S STILL LOOKS PRETTY CLOSE WITH THE COOLER TEMPS IN THE LOW LYING AREAS OF THE KS RIVER. THE RETURN TO SOUTHERLY WINDS ON SUNDAY WILL AID IN TEMPS RISING INTO THE UPPER 60S TO NEAR 70 DEGREES. WITH SOUTHWEST/SOUTH 850 WINDS CONTINUING INTO MONDAY AND 850 TEMPS RISING INTO THE LOW TO MID TEENS DEGREES C...SUNSHINE WILL LEAD TO EVEN WARMER TEMPS INTO THE MIDDLE 70S BY MONDAY AFTERNOON. NEXT SHORTWAVE EMERGING INTO THE PLAINS FROM THE SOUTHWEST WILL ARRIVE ON TUESDAY AS LOW PRESSURE FORMS IN THE CENTRAL HIGH PLAINS THEN LIFTS NORTHEAST INTO THE NORTHERN PLAINS. THIS WAVE IS NOT AS STRONG AS EARLIER MODEL RUNS AS IT MOVES INTO THE UPPER RIDGE OVER THE PLAINS AND LIFTS FURTHER NORTH. AS A RESULT...CONVERGENCE ALONG THE FRONT IS NOT AS STRONG AND LIFT APPEARS WEAKER. HOWEVER...IS STILL APPEARS A FEW SHOWERS OR THUNDERSTORMS COULD DEVELOP AHEAD OF THE FRONT LATE MONDAY NIGHT AND THROUGH THE DAY TUESDAY...THEN ACROSS MAINLY THE SOUTHEAST HALF OF THE CWA TUESDAY NIGHT...THEN DRY ON WEDNESDAY AS BOUNDARY STALLS TO THE SOUTH AND WASHES OUT/LIFTS BACK TO THE NORTH IN RESPONSE TO STRONGER UPPER TROUGH DIGGING INTO THE FAR SOUTHWESTERN U.S....WITH LEESIDE TROUGHING STRENGTHENING AGAIN. THIS WILL ALLOW FOR HIGH TEMPS TO BE IN THE MIDDLE TO UPPER 70S WEDNESDAY THROUGH FRIDAY. FOR NOW...HAVE KEPT FCST DRY...BUT IF THE UPPER TROUGH EJECTS OUT QUICKER INTO THE PLAINS BY THE END OF THE WEEK...MAY NEED TO CONSIDER ADDING POPS TO FRIDAY. && .TOP WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 8 PM ALONG AND TO THE WEST OF A WASHINGTON...MANHATTAN TO COUNCIL GROVE LINE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 550 PM EDT FRI APR 7 2006 .DISCUSSION...UPPER LEVEL LOW OVER QUEBEC AND SHORTWAVE OVER THE GREAT PLAINS WILL COMBINE OVER THE NEXT 24-48 HOURS TO FORM A BROAD LONG WAVE TROUGH THAT WILL PUSH OVER THE EAST COAST BY SUNDAY. RIDGING WILL BUILD OVER THE MIDWEST DURING THIS TIME FRAME...AS HIGH PRESSURE AT THE SURFACE CHARGES INTO THE OHIO VALLEY. THIS WILL HELP TEMPERATURES REBOUND VIA WARM AIR ADVECTION AND DRY WEATHER TO RETURN TO MICHIGAN ON SUNDAY AND MONDAY AFTER A DAY OR TWO OF COOL/WET CONDITIONS. IN THE MEANTIME...SURFACE/RUC ANALYSIS WV/IR/VIS IMAGERY SHOW TWO UPPER LEVEL LOWS...ONE OVER QUEBEC AND THE OTHER OVER KANSAS. A SHORTWAVE IS SWINGING SOUTHWARD ACROSS LAKE SUPERIOR ATTM. SURFACE ANALYSIS SHOWS LOW PRESSURE OVER EASTERN KANSAS WITH A WARM FRONT LYING ACROSS NORTHERN ILL/IND/OH. A SECONDARY TROUGH IS MOVING SOUTHWARD ACROSS CENTRAL MI WITH COOLER TEMPS AND DWPTS...AND GUSTY NE WINDS BEHIND IT. CURRENT RADAR IS SHOWING SMALL AREA OF PRECIP STRETCHING FROM EAST TAWAS TO CENTRAL WISCONSIN ASSOCIATED WITH UPPER LEVEL DIVERGENCE/-DIV Q/AND FGEN BAND. MAIN FORECAST CONCERNS INCLUDE PRECIP ACROSS THE FAR SOUTHERN PART OF THE CWA...THEN THE FOCUS SHIFTS TO LAKE EFFECT CLOUDS/PRECIP CHANCES FOR TONIGHT INTO SATURDAY. TONIGHT...NAM/GFS SHOW THE LEADING EDGE OF 850-700MB DRY AIR (RH 15-25%) CLEARING THE AREA BY 00Z THIS EVENING WHILE THE 500 MB SHORTWAVE DOES NOT PASS SOUTH OF THE CWA UNTIL 03Z. HOWEVER...WITH FGEN AND 700-500MB -DIV Q HANGING ON ACROSS THE FAR SOUTHEASTERN PART OF THE CWA...WILL NOT REMOVE POPS (GLADWIN AND ARENAC COUNTIES) UNTIL THE SHORTWAVE FINALLY CLEARS THE AREA. SO...WILL LEAVE A SLIGHT CHANCE OF RAIN SHOWERS...POSSIBLY MIXED WITH SNOW FOR THE AFOREMENTIONED COUNTIES THIS EVENING. ACROSS THE REST OF THE CWA...HIGH PRESSURE AND NORTHERLY WINDS SETTLE INTO THE AREA. TEMPERATURES AT THE TOP OF THE 3.5-4KFT MIXED LAYER WILL RANGE FROM -8C TO -11C OVERNIGHT...PRODUCING DELTA T'S COOL ENOUGH FOR LAKE INDUCED CLOUDS (10C TO 13C) COVER NORTHERLY FLOW AFFECTED REGIONS. 850MB-700MB RH VALUES WILL START OUT MINISCULE AT 00Z (RH 15-20%) BUT IMPROVE TO GREATER THAN 70 PERCENT BY 12Z OVER EASTERN UPPER AND NE LOWER. WILL LEAVE FLURRIES IN THE FORECAST FOR OVERNIGHT BUT WILL REFRAIN FROM MENTIONING SNOW SHOWERS. WINDS WILL GRADUALLY SUBSIDE OVERNIGHT...BUT STILL IN SMALL CRAFT CRITERIA RANGE. .LONG TERM...MODELS REMAIN IN GOOD AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK WITH THE UPPER LEVEL PATTERN REMAINING HIGHLY AMPLIFIED. BIGGEST MODEL DISCREPANCY CENTERS AROUND THE AMPLIFICATION OF THE RIDGE WHICH WILL BE IN CONTROL OF THE WEATHER FOR THE END OF THE WEEKEND AND FIRST PART OF NEXT WEEK. THE NEXT WEATHER SYSTEMS TO IMPACT THE REGION WILL ARRIVE TUESDAY NIGHT AND LATE THURSDAY NIGHT/EARLY FRIDAY MORNING...WITH THE UPPER LEVEL RIDGE PUSHING THE SYSTEM NORTHWEST OF THE CWA. MAIN LONG TERM CONCERNS FOCUS ON CHANCE OF PRECIPITATION/TYPE SATURDAY MORNING AND PRECIPITATION FOR TUESDAY NIGHT AND LATE THURSDAY/FRIDAY. SATURDAY AND SATURDAY NIGHT...UPPER LEVEL TROUGH WILL SWING ACROSS THE NORTHERN REACHES OF THE CWA WITH 850 MB TEMPERATURES REMAINING AROUND -8C THROUGH THE AFTERNOON. WITH THE TROUGH PASSING TO THE NORTH 850-700 MB LAYER RH WILL BE 60 PCT OVER NORTHERN LOWER AND 75 PCT IN EASTERN UPPER. EVEN WITH THE MOISTURE IN THE COLUMN...IT WILL STRUGGLE TO REACH THE -13C TO -20C LAYER SUBSTANTIALLY LIMITING SNOW FALL POTENTIAL. LATE SATURDAY MORNING AND THROUGH THE AFTERNOON THE TROUGH SLIDES EAST WITH DRIER AIR MOVING IN FROM THE NORTH (850-700 MB LAYER RH DECREASES TO LESS THAN 60 PCT BY 00Z). WITH THOSE FACTORS IN MIND WILL CONTINUE WITH THE CHANCE OF FLURRIES ACROSS EASTERN UPPER AND THE N AND NNW FLOW LAKE EFFECT AREAS OF NORTHERN LOWER. WITH THE TROUGH EAST OF THE AREA SATURDAY EVENING...HIGH PRESSURE AND THE UPPER LEVEL RIDGE WILL BUILD INTO THE REGION ENDING THE THREAT OF FLURRIES AND DIMINISHING THE CLOUD COVER. SUNDAY AND SUNDAY NIGHT...HIGH PRESSURE WILL SLIDE JUST EAST OF THE REGION WITH THE UPPER LEVEL RIDGE BUILDING FURTHER OVER THE WESTERN GREAT LAKES. WITH SOUTHERLY WINDS ENVELOPING THE AREA WAA WILL SLOWLY EDGE TEMPERATURES BACK TOWARD NORMAL (LOWER 50S FOR MOST LOCATIONS). SUNDAY NIGHT ANOTHER MINOR SHORT WAVE TROUGH WILL CROSS THE UPPER MISSISSIPPI VALLEY AND ACROSS EASTERN UPPER. GFS HAS AMPLIFIED THIS FEATURE OVER THE PAST SEVERAL RUNS WHILE OTHER MODELS KEEP THE SYSTEM AS AN OPEN WAVE WITH MUCH LESS MOISTURE. AS A RESULT HAVE TRENDED AWAY FROM THE GFS AND GONE WITH A ECMWF/NAM BLEND. WITH THE SOUTHERLY BREEZES SUNDAY NIGHT AND THE WAA CONTINUING WILL EXPECT TEMPERATURES TO STAY WARMER THAN PREVIOUS NIGHTS...BOTTOMING OUT NEAR NORMAL IN THE UPPER 20S TO LOWER 30S ACROSS THE CWA. MONDAY AND MONDAY NIGHT...LOW PRESSURE WILL DEEPEN OVER WESTERN NEBRASKA WITH ANOTHER MINOR SHORT WAVE TROUGH CROSSING MINNESOTA. THE GFS AGAIN OVER-DEEPENS THE TROUGH...SO WILL TREND TOWARD THE ECMWF AND NAM BLEND AGAIN. THIS WILL RESULT IN A PARTLY SUNNY DAY WITH THE GREATEST AMOUNT OF CLOUDINESS ACROSS EASTERN UPPER AS THE BEST MOISTURE WILL BE IN THIS REGION. MONDAY NIGHT THE LOW PRESSURE FROM NEBRASKA WILL MOVE NORTHWARD THROUGH THE DAKOTA/S AND INTO SOUTHERN MANITOBA. THIS WILL KEEP THE SOUTHERLY WINDS AND WAA OVER THE REGION WITH THE UPPER LEVEL RIDGE AXIS CENTERED OVER LAKE MICHIGAN RESULTS WILL BE ANOTHER TRANQUIL NIGHT WITH TEMPERATURES IN THE MIDDLE TO UPPER 30S (SLIGHTLY ABOVE NORMAL). TUESDAY AND THE REMAINDER OF THE EXTENDED...UPPER LEVEL RIDGE WILL SLOWLY EDGE EASTWARD THROUGH WEDNESDAY MORNING ALLOWING A COLD FRONT ASSOCIATED WITH THE LOW IN MANITOBA TO PUSH THROUGH MICHIGAN TUESDAY NIGHT AND WEDNESDAY. ALTHOUGH PRELIMINARY DYNAMICS APPEAR WEAK WITH THE COLD FRONT THERE IS SOME INSTABILITY SO WILL INCLUDE A CHANCE OF THUNDER FOR TUESDAY NIGHT. HIGH PRESSURE WILL RETURN WEDNESDAY AFTERNOON AND THURSDAY WITH THE NEXT POTENTIAL WEATHER MAKER ARRIVING LATE THURSDAY/FRIDAY. MODEL DIFFERENCES ARE MODERATE WITH THIS SYSTEM SO HAVE ADDED A CHANCE OF RAIN SHOWERS ACROSS THE NORTHERN HALF OF THE CWA FOR FRIDAY AND FRIDAY NIGHT. && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 430 PM EDT FRI APR 7 2006 .DISCUSSION... MAIN FCST CONCERNS SHIFT FROM LIGHT LAKE EFFECT SNOW TONIGHT INTO EARLY SAT TO SHRA/TSRA CHANCES NEXT WEEK. WV IMAGERY...12Z RAOBS AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE SPLIT FLOW PATTERN WITH THE UPR GREAT LAKES DOMINATED BY NRN STREAM NW MID/UPR LVL FLOW AROUND A CLOSED LOW SE OF JAMES BAY. ANOTHER POTENT CLOSED LOW WAS SPINNING OVER THE CNTRL PLAINS DOWNSTREAM FROM A RDG FROM THE SW CONUS INTO CNTRL CANADA. A SHRTWV TROF THAT HELPED SUPPORT A PERIOD OF -SHSN WAS SLIDING SSE THROUGH UPR MI. THE 18Z KCMX TAMDAR SNDG INVERSION HGT TEMP AT 840 MB NEAR -14C...WHICH WAS COLDER THAN BOTH THE GFS(-12C) AND NAM(-10C) FCSTS... PROVIDED ENOUGH INSTABILITY FOR THE LES. HOWEVER THE -SHSN HAS QUICKLY DIMINISHED THIS AFTERNOON DUE TO THE COMBINATION OF SUBSIDENCE BEHIND THE SHRTWV AND DIURNAL HEATING/MIXING. UPSTREAM DEWPOINTS HAD FALLEN TO NEAR 10F WITH FAIRLY LARGE 1000-850 DEWPOINT DEPRESSIONS...PER 16Z KINL TAMDAR SNDG. TONIGHT...EXPECT THAT THE THE LES WILL CONTINUE TO FADE THIS EVENING AS THE DRIER AIR AND ACYC FLOW SPREAD THROUGH UPR MI AND INVERSION HGTS LOWER BEHIND THE SHRTWV. ANOTHER WEAK SHRTWV UPSTREAM OVER NRN ONTARIO WAS MOVING TO THE SSE BUT SHOULD REMAIN FAR ENOUGH E SO THAT IT WILL HAVE ONLY A MINOR IMPACT ON THE WEATHER OVER THE CWA. TYPICAL DIURNAL TRENDS SHOULD ALLOW LAKE CLOUDS AND SOME INCREASE IN CONVERGENCE TO DEVELOP OVER THE LAKE. IN ADDITION...A SECONDARY 900-700 THERMAL TROF WILL SLIDE THROUGH MAINLY THE E HLF OF LK SUPERIOR. GIVEN THE AFTERNOON OBS...THE COLDER GFS 900-850 MB TEMPS NEAR -12C OVER E LK SUPERIOR WERE PREFERRED. SO...WITH ONLY MARGINAL INSTABILITY...ONLY PATCHY/SCT FLURRIES AT MOST ARE EXPECTED MAINLY OVER THE ERN CWA. THE COLDER TEMPS AT THE TOP OF THE INVERSION SHOULD ALSO MINIMIZE ANY THREAT FOR -FZDZ. SATURDAY...WITH LOWERING INVERSION HGTS...INCREASED UPSTREAM MIXING AND BACKING WINDS...REMAINING FLURRIES OVER THE E HLF SHOULD END BY AFTERNOON. OTHERWISE...MIXING TO 850 MB(-5C) SHOULD PUSH TEMPS INTO THE UPPER 30S AND LOWER AND MID 40S. SATURDAY NIGHT INTO SUN...MDLS SUGGEST ANOTHER WEAK SHRTWV IN NW FLOW REGIME AND ASSOCIATED 300K ISENTROPIC LIFT MAY BRING A BATCH OF MID CLOUDS THROUGH THE AREA SAT NIGHT. THIS MAY KEEP TEMPS FROM DROPPING OFF AS MUCH DESPITE PRESENCE OF SFC RDGING OVER THE AREA. SUNSHINE AND RETURN FLOW SRLY FLOW WAA SUPPORTS TEMPS INTO THE MID 50S AS MDLS PUSH H8 TEMPS TO NEAR 1C. GRADIENT SHOULD STILL BE WEAK ENOUGH FOR LAKE BREEZE DEVELOPMENT OFF OF LK SUPERIOR. MON...THE 12Z GFS WAS MUCH STRONGER WITH A LEAD SHRTWV MOVING THROUGH THE SRN CANADA RDG. TRENDS FROM THE 00Z/12 12Z/07 ECMWF ALSO HINTS AT THE FEATURE BUT WAS MUCH WEAKER AND FARTHER TO THE NORTH. SINCE THE GFS WAS A LARGE DEPARTURE FROM ITS PREVIOUS RUN AND WAS LIKELY CONTAMINATED BY CONVECTIVE FEEDBACK...PER HPC DIAGNOSTIC DISC...PREFERRED TO KEEP DRY FCST...IN LINE WITH CONTINUITY. TUE-FRI...GIVEN A TREND TOWARD PATTERN AMPLIFICATION...THE SLOWER ECMWF WAS PREFERRED IN BRINGING MOISTURE AND ASSOCIATED SHRA/TSRA CHANCES INTO UPR MI TUE INTO TUE NIGHT. FOLLOWING A COMBINATION OF THE ECMWF AND GFS ENS MEAN SUGGESTS THAT A COLD FRONT WILL MOVE THROUGH EARLY WED WITH POTENTIAL FOR SOME INSTABILITY SHOWERS WITH WRAP AROUND MOISTURE IF THE MID LVL TROF IS STRONGER AND FAR ENOUGH S. A HEDGE TOWARD THE ENS MEAN WOULD BRING IN SHOWER CHANCES AGAIN BY LATER FRIDAY WITH WAA AND RETURN OF MOISTURE WITH NEXT MID LVL TROF EDGES INTO THE PLAINS. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 148 PM EDT FRI APR 7 2006 .UPDATE... UPDATE PART TWO. TEMPS CONTINUE TO FALL IN FACE OF STRONG COLD AIR ADVECTION. READINGS ARE NOW AS COLD AS THE MIDDLE 20S OVR THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH CENTRAL. WHERE SUNSHINE IS APPEARING (SW UPR MI) TEMPS ARE AT LEAST BECOMING MORE STEADY AROUND 30F. ADDED SCATTERED SNOW SHOWERS INTO NW AND NCNTRL AS FLURRIES ARE A BIT MORE WIDESPREAD AND VIBILITIES HAVE LOWERED OCCASIONALLY TO LESS THAN 3SM. ALTHOUGH HIGHER SUN ANGLE IS NOT HELPING TO WARM AIR TEMPERATURES IT IS HELPING TO MELT THE SNOW THAT IS OCCURRING. THUS...DO NOT EXPECT ANY ACCUMS ABOVE A FEW TENTHS OF AN INCH. TAIL OF SHORTWAVE OVR QUEBEC SHIFTS SWD OUT OF AREA LATE THIS AFTN WITH TEMPS IN THE H9-H85 LAYER BEGINNING TO WARM. THUS...EXPECT COVERAGE AND INTENSITY OF SNOW SHOWERS TO DIMINISH BY LATE AFTN. STILL MAY SEE A SLIGHT RISE IN TEMPS IF CLOUDS BREAK A BIT MORE. UPDATED AND PUBLISHED GRIDS ARE OUT. TEXT ZFPMQT UPDATE SHORTLY. && .PREV DISCUSSION (ISSUED AT 332 AM EDT)... THE MAIN CONCERNS WITH THIS FORECAST PACKAGE ARE WITH THE WINDS TODAY AND THE CHANCE OF PRECIPITATION TONIGHT. WATER VAPOR IMAGERY AND RUC/NAM SHOWING DEEP LOWS OVER NORTHEAST KANSAS AND OVER SOUTHERN JAMES BAY...WITH A RIDGE SEPARATING THESE EXTENDING FROM THE OHIO RIVER VALLEY THROUGH WISCONSIN...INTO NORTH DAKOTA. ANOTHER RIDGE EXTENDS FROM THE SOUTHERN ROCKIES THROUGH MONTANA INTO THE CANADIAN PRAIRIES. SURFACE ANALYSIS SHOWING A LOW OVER SOUTHEAST NEBRASKA. A FRONTAL SYSTEM EXTENDS EAST FROM THIS LOW THROUGH THE LOWER GREAT LAKES INTO SOUTHWEST QUEBEC. A FRONT ALSO RUNS WEST FROM THE NEBRASKA LOW THROUGH WYOMING AND WESTERN MONTANA. A BROAD RIDGE IS OVER CENTRAL CANADA. THE JAMES BAY MID LEVEL LOW WILL SHIFT INTO SOUTHWEST QUEBEC... WHILE THE LOW OVER NORTH KANSAS SLIDES INTO OKLAHOMA TODAY. A WEAK SHORTWAVE WRAPPING AROUND THE JAMES BAY LOW WILL SWEEP THROUGH THE FORECAST AREA. SOUNDINGS SHOWING AN INVERSION AT AROUND 3.5K FEET. CONDITIONS ARE VERY DRY ABOVE THE INVERSION BUT RATHER HIGH RH JUST BELOW THIS LEVEL. THEREFORE...EXPECT CONSIDERABLE LOW CLOUDS. THE FORECAST MODELS SHOW THAT IT WILL CONTINUE TO BE FAIRLY DRY AT THE SURFACE. THEREFORE...THE SNOW WILL HAVE TO SATURATE OUT THE LOW LEVELS BEFORE GETTING TO THE SURFACE. SURFACE TO 900MB LAPSE RATE WILL BE ON THE ORDER OF 8.5-9.5C/KM. STRONGEST 900MB OMEGA WILL BE NORTH OF M-28 FROM KIWD TO KSAW. I WILL BE LOOKING FOR A CHANCE OF SOME FLURRIES THERE TODAY. A WARMING AT THE SURFACE WILL REDUCE CHANCE OF PRECIPITATION IN THE AFTERNOON...AS THE RH LOWERS THROUGH THE DAY. THE LOW LEVEL INVERSION WILL ALLOW SOME OF WINDS AT 925MB TO MIX TO SURFACE ESPECIALLY OVER LAKE SUPERIOR. SO WILL KEEP SOME BREEZY GUSTY CONDITIONS THROUGH THE DAY. ANOTHER SHORTWAVE ROTATING THROUGH THE BASE OF THE QUEBEC LOW WILL SWEEP THROUGH THE FORECAST AREA TONIGHT. THE CANADIAN SURFACE WILL SLIDE OVER THE NORTHERN AND CENTRAL PLAINS. THE LAYER AROUND 900MB WILL REMAIN FAIRLY MOIST WHICH WILL HELP IN PRODUCING SOME PRECIPITATION. MODELS SOUNDINGS CONTINUE TO SHOW NEARLY DRY AT THE SURFACE...AND SURFACE-900MB LAPSE RATE AROUND 8.5C/KM. TEMPERATURES WILL BE WELL BELOW FREEZING...THEREFORE...LOOKING FOR A CHANCE OF SOME LIGHT SNOW OR FLURRIES OVERNIGHT. TRAJECTORY FORECAST AND GUIDANCE INDICATE THAT THE OVERNIGHT LOWS SHOULD DIP INTO THE MID TO LOW 20S WHICH WITH THE EXPECTED WINDS AND CLOUDY CONDITIONS SOUND REASONABLE. ANOTHER VERY WEAK SHORTWAVE WILL SWEEP THROUGH THE AREA ON SATURDAY. THE SURFACE RIDGE WILL EXPAND TO BLANKET THE UPPER GREAT LAKES ON SATURDAY AND SLIDE INTO THE OHIO RIVER VALLEY ON SUNDAY. THE AIR MASS WILL BE VERY STABLE AND DRY WHICH WILL KEEP FAIR CONDITIONS THROUGH THE WEEKEND. THE MID LEVEL RIDGE WILL WEAKEN AS IT SLIDE OVER THE UPPER GREAT LAKES ON SUNDAY NIGHT. A WEAK SHORTWAVE SHIFTING THROUGH THIS RIDGE WILL BE OVER THE FORECAST AREA SUNDAY NIGHT. A LOW WILL DEVELOP OVER THE NORTHERN PLAINS WITH A COLD FRONT. A SOUTHWEST FLOW WILL OCCUR ON THE BACKSIDE OF THE RIDGE DRAWING WARMER MOIST AIR FROM THE GULF INTO THE AREA. THE NORTHERN PLAINS LOW WILL MOVE INTO THE FORECAST AREA LATE ON TUESDAY AND BRING AN INCREASE CHANCE OF SHOWERS TO THE REGION. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JLA PREV DISCUSSION...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 425 PM CDT FRI APR 7 2006 .DISCUSSION... NO NEED FOR CHANGES TO THE SHORT TERM...THE FORECAST IS ON TRACK. THE MODELS HAVE SOME SUBTLE DIFFERENCES...BUT OVERALL STILL LOOKS LIKE THE UPPER LOW WILL CONTINUE TO DIG SOUTH. STRONG SOUTHERLY WINDS CONTINUE TO BRING MOISTURE INTO THE REGION...DEWPOINTS ACTUALLY CLIMBED INTO THE MID AND UPPER 70S. RUC ANALYSIS SHOWS 3 HOUR PRESSURE FALLS FROM 3-4MB ACROSS THE AREA AND SURFACE LI VALUES WERE FROM 6-7C FROM JAN TO GLH...IN THE AREA WHERE STORMS HAVE DEVELOPED. THE BEST MOISTURE WAS ALSO IN THE SAME GENERAL AREA. SUPERCELLS HAVE STARTED TO DEVELOP...MAINLY OVER THE DELTA...WHERE THEY WERE EXPECTED TO DEVELOP INITIALLY. TRAINING STORMS MAY BRING THE FLASH FLOOD PROBLEMS PREVIOUSLY THOUGHT ALSO. THE CAP CONTINUES TO ERODE...SO THE ACTIVITY WILL INCREASE QUICKLY TO THE SOUTH AND EAST. THE LATEST SOUNDING SHOWS STEEP LAPSE RATES...A 45KT LLJ AND AT LEAST 45KTS OF SHEAR. HOWEVER MODEL SOUNDINGS MAINTAIN A CAP OVER THE SOUTHEAST UNTIL 3Z. SO EXPECTING THE AXIS TO SHIFT SOUTHEAST INTO THE CENTRAL PORTIONS OF THE CWA BY 6PM AND INTO THE EASTERN ZONES AROUND 8-9 PM. WITH STORMS DEVELOPING LATER THAN EXPECTED...NOT SURE ACTIVITY WILL END SHORTLY AFTER MIDNIGHT. HELD STORMS THROUGH MIDNIGHT FOR THE CENTRAL AND EAST AND A FEW SHOWERS THROUGH THE MORNING FOR THE EAST. BASICALLY THE FORECAST HAS HANDLED THIS SYSTEM WELL FOR THE LAST FEW DAYS...SO NEED FOR ADJUSTMENTS. NO MAJOR CHANGES MADE TO THE GOING LONG TERM FORECAST. LONG TERM MODELS AND ENSEMBLE SOLUTIONS REMAIN IN DECENT AGREEMENT THAT THE ARKLAMISS REGION WILL GENERALLY BE AWAY FROM THE FIRING LINES OF UPPER JET ENERGY THROUGH NEXT FRIDAY. THAT SAID...A FAST MOVING DISTURBANCE WILL TRY TO MAKE HEADWAY INTO THE TOP END OF AN UPPER RIDGE PROTECTING THE AREA BY WEDNESDAY. THIS FEATURE...IN COMBINATION WITH A LITTLE MOISTURE TRYING TO SNEAK IN FROM THE ARKLATEX...MAY BE ENOUGH TO GET SOME CONVECTION GOING (ESPECIALLY UP NORTH). THE UPPER RIDGE MAY REMAIN A LITTLE "DIRTY" THROUGH THE REMAINDER OF NEXT WEEK IN THE WAKE OF THIS INITIAL DISTURBANCE...AND WILL THEREFORE KEEP THE LOW AND SPORADIC POPS THE 00Z MEX ADVERTISED. OTHERWISE...EXPECT GENERALLY PARTLY CLOUDY (TO SOMETIMES MOSTLY CLEAR) SKIES THROUGH THE BULK OF THE EXTENDED PERIOD. TEMPERATURES WILL TEND A HAIR BELOW NORMAL THE FIRST PART OF NEXT WEEK WITH SURFACE HIGH PRESSURE IN CONTROL...BUT EXPECT A MODERATION UP TO NORMAL LEVELS (HIGHS NEAR 80/LOWS NEAR 60) DURING THE LATTER HALF OF THE PERIOD. REMAINED ALMOST RIGHT WITH 00Z MEX FOR ALL TEMPS. /BB/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 62 70 43 71 / 85 7 0 0 MERIDIAN 63 74 41 74 / 100 19 0 0 VICKSBURG 61 69 44 71 / 60 5 0 0 HATTIESBURG 67 75 44 75 / 60 13 0 0 NATCHEZ 61 70 44 71 / 48 4 0 0 GREENVILLE 59 65 40 68 / 71 5 0 0 GREENWOOD 60 65 40 70 / 85 9 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 07/50 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 143 PM CDT FRI APR 7 2006 .DISCUSSION... DID A QUICK UPDATE TO ADD THE WATCH AND ADJUST THE WEATHER GRIDS. TEMPERATURES STILL SEEM TO BE ON TRACK. WITH SIGNIFICANT WEATHER EXPECTED TO DEVELOP OVER THE CWA IN THE NEXT FEW HOURS...OPTED NOT TO ISSUE LKY THIS AFTERNOON. WINDS ALONG THE RIVER REMAIN AROUND 20KTS WITH HIGHER GUSTS AND SHOULD CONTINUE THROUGH THE EVENING. STORMS CONTINUES TO DEVELOP TO THE NORTHWEST AND TRACK OFF NORTHEAST...JUST MISSING THE CWA. WIDESPREAD LARGE HAIL HAS OCCURRED...SO EXPECTING IT ONCE THINGS GET STARTED. RUC THETA E VALUES WERE AROUND 345K AND QUICKLY SPREADING NORTHEAST. STILL EXPECTING THE STORMS TO DEVELOP OVER THE DELTA IN THE NEXT HOUR OR TWO AND SHIFT SOUTH...WITH ACTIVITY BEING DELAYED TO AFTER 4 FOR THE JACKSON METRO AREA. SOUNDINGS STILL SHOW A CAP OVER THE AREA...BUT THERE WAS PLENTY OF ELEVATED INSTABILITY. ANYWAY...NO REAL CHANGES FOR THE SHORT TERM. && .AVIATION... STILL EXPECTING SCATTERED ACTIVITY...SO TRIED TO ADJUST THE TIMING. WITH NO OBS COMING IN FOR GLH...HAD TO NIL THE TAF FOR NOW. ANYWAY...DELAYED ANY THUNDERSTORM DEVELOPMENT UNTIL ABOUT 4 OR 5 PM FOR MOST OF THE AREA. MAINTAINED HAIL AND DAMAGING WINDS FOR ALL GROUPS THROUGH THE EVENING. STILL EXPECTING STORMS TO END FROM THE WEST...WITH ACTIVITY ENDING IN GLH/GWO AROUND 6Z...JAN 6-8Z AND HOLDING FOR GTR/MEI AND HBG THROUGH 12Z. BY 15Z VFR CONDITIONS SHOULD PREVAIL. A TROUGH AXIS WAS EXPECTED TO PASS JUST NORTH OF THE AREA...SO CLOUDS MAY CLEAR BRIEFLY AND FILL BACK IN...BUT EXPECTING HEIGHTS TO REMAIN ABOVE 3KFT. A SHOWER MAY BE POSSIBLE AROUND GTR LATE IN THE MORNING...BUT RAINFALL AMOUNTS WILL BE LIGHT...SO NOT LOOKING FOR ANY OBSTRUCTIONS TO THE VISIBILITIES. && .PRELIMINARY POINT TEMPS/POPS... JACKSON 85 62 69 43 / 42 85 17 6 MERIDIAN 87 63 73 41 / 35 100 22 5 VICKSBURG 84 61 68 44 / 42 60 15 7 HATTIESBURG 86 67 77 46 / 15 60 23 1 NATCHEZ 82 61 69 44 / 24 48 13 2 GREENVILLE 81 59 61 41 / 67 71 10 5 GREENWOOD 81 60 64 40 / 66 85 13 5 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 07 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 610 PM EDT FRI APR 7 2006 .SHORT TERM(TNGT)... ADDED SEVERE THUNDERSTORM WATCH...WILL REMOVE COUNITES AS SOON AS POSSIBLE. && .SHORT TERM (TNGT)... DENSE FOG ROLLING IN FROM THE LAKE BEHIND THE COLD FRONT. TYPICALLY THE DENSE FOG JUST LASTS A FEW HOURS. UPDATED LAKESHORE ZONES TO INDICATE THE FOG. WILL MONITOR AND UPDATE TO DENSE FOG ADVISORY IF NEEDED. && .SHORT TERM(TNGT-SUN)... SFC LOW PRES NOW NEAR KERI AND CONTINUING TO MOVE OFF TO THE E. TRAILING FRONT NOW SLOWLY MOVING S AS SEEN BY LATEST SATELLITE IMAGERY. FRONT SHOULD MAKE IT AS FAR S AS KMFD BY 21Z AND BE WELL S OF THE AREA BY 00Z. LOW CLOUDS AND COOLER AIR BEHIND FNT WILL PUT AN END TO THE TSRA THREAT. FOR THE TIME BEING ONLY FAR SRN 1/3 TO 1/2 OF ZONES HAVE ANY SIGNIFICANT THREAT TO SEE T ACTIVITY AND THAT THREAT WILL RAPIDLY DIMINISH EARLY THIS EVE. LATEST NAM...RUC AND GFS FAIRLY SIMILAR WITH TIMING OF FRONT AND LOW 1ST PERIOD. VERY DRY AIR WILL FILTER IN BEHIND FRONT TONIGHT BUT VERY STRONG LLVL INVERSION TO SET UP FOR FIRST 2/3 OF THE NIGHT. COULD BE SUM SPITS OR SHRA THRU THE EARLY AM HOURS. WAS EARLIER CONCERNED ABOUT POSSIBLE FZDZ OVERNIGHT BUT NOW DRIER AIR COMES BEFORE TEMPS GET COLD ENUF. 850 MB TEMPS BOTTOM OUT AROUND NEG 6 MIDDAY TOMORROW AND THEN START TO MODERATE. COULD BE A FAIR AMOUNT SC TOMORROW AM BUT DO EXPECT SKIES TO BECOME M/SUNNY DURING THE AFT AS SFC TO 700 MB MEAN RH FALLS TO AROUND 30 PERCENT. WILL BE CHILLY ALONG S SHORE OF LERI TOMORROW WITH NLY FLOW OFF LAKE. SUN WILL GET OFF TO A COOL START WITH HIGH PRES OVERHEAD AT DAYBREAK. HI TEMPS SUN WILL AVERAGE AROUND NORMAL WITH A LOT OF SUNSHINE. && .LONG TERM (SUN NIGHT THROUGH FRI)... EXTENDED RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE BIG PICTURE TDA. SO..FOR THE TIME BEING IT LOOKS WE SHOULD SEE A RELATIVELY QUIET EXTENDED PD WITH SPRING LIKE WX ONCE WE GET PAST THE WEEKEND. HIGH PRES WILL DIVE OVER THE WRN GRTLKS TOMORROW AND THEN BUILD ACROSS THE FORECAST AREA THRU THE START OF THE NEW WORKWEEK. HI SHOULD BE OVERHEAD SUNDAY AFT AND EVE AND THEN SHIFTS OFF TO THE EAST COAST BY MONDAY EVE. SO AFTER A COOL WEEKEND WITH TEMPS AVERAGING A LITTLE BELOW NORMAL...TEMPS WILL BEGIN TO MODERATE MON AND TUE WITH HIGH TEMPS BOTH DAYS IN THE LOWER 60S. BY EARLY WED...THERE WILL BE ENUF WAA TO POSSIBLY CAUSE A FEW SHRA OR TSRA. MORE STORMS POSSIBLE WED NIGHT INTO THU AS A COLD FRONT PASSES THRU REGION. LINGERING SHRA IN THE E ON THU IN THE CAA BEHIND THE BOUNDARY. RIDGE SLIDES ACROSS REGION THU NIGHT AND WL BACK IN WAA FLOW BY END OF PD. && .AVIATION(18Z-18Z)... THE NORTHWARD TREND OF THE WARM ADVECTION HAS NOW BEGUN TO RETREAT SOUTHWARD. AS EACH HOUR GOES BY THE NORTHERLY FLOW WILL DIMINISH OUR CHANCE OF TSTMS AND SVR WX FOR EXTREME NRN OHIO....FOR AREAS TO THE SOUTH OF CLE...JUST A LITTLE SUNSHINE IS NEEDED TO GET THE ATMOSPHERE TO DESTABILIZE EVEN FURTHER. WE WILL CONT TO MONITOR FOR WX WATCH THIS AFTN POSSIBLY FOR OUR SRN CWA. AS THE WARM FRONT RETREATS SOUTHWARD AS A COLD FRONT...THE COOLER AIR MASS WILL BRING NORTHERLY WINDS AND A SLIGT CHC OF MIXED RAIN AND SNOW SHOWERS TNGT. SOME LGT DRIZZLE WITH LOW CIGS IS A GOOD POSSIBILITY AS INDICATED ON BUFKIT SOUNDING. EXCEPT FOR SOME BRIEF VFR CONDS EARLY THIS AFTN VCNTY MFD LOOK FOR IFR OR NEAR IFR CONDS TO DOMINATE NEXT 12 TO 18 HOURS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ SHORT TERM...KUBINA/KIELTYKA LONG TERM...KUBINA AVIATION...BC oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 428 PM EDT FRI APR 7 2006 .SHORT TERM (TNGT)... DENSE FOG ROLLING IN FROM THE LAKE BEHIND THE COLD FRONT. TYPICALLY THE DENSE FOG JUST LASTS A FEW HOURS. UPDATED LAKESHORE ZONES TO INDICATE THE FOG. WILL MONITOR AND UPDATE TO DENSE FOG ADVISORY IF NEEDED. && .SHORT TERM(TNGT-SUN)... SFC LOW PRES NOW NEAR KERI AND CONTINUING TO MOVE OFF TO THE E. TRAILING FRONT NOW SLOWLY MOVING S AS SEEN BY LATEST SATELLITE IMAGERY. FRONT SHOULD MAKE IT AS FAR S AS KMFD BY 21Z AND BE WELL S OF THE AREA BY 00Z. LOW CLOUDS AND COOLER AIR BEHIND FNT WILL PUT AN END TO THE TSRA THREAT. FOR THE TIME BEING ONLY FAR SRN 1/3 TO 1/2 OF ZONES HAVE ANY SIGNIFICANT THREAT TO SEE T ACTIVITY AND THAT THREAT WILL RAPIDLY DIMINISH EARLY THIS EVE. LATEST NAM...RUC AND GFS FAIRLY SIMILAR WITH TIMING OF FRONT AND LOW 1ST PERIOD. VERY DRY AIR WILL FILTER IN BEHIND FRONT TONIGHT BUT VERY STRONG LLVL INVERSION TO SET UP FOR FIRST 2/3 OF THE NIGHT. COULD BE SUM SPITS OR SHRA THRU THE EARLY AM HOURS. WAS EARLIER CONCERNED ABOUT POSSIBLE FZDZ OVERNIGHT BUT NOW DRIER AIR COMES BEFORE TEMPS GET COLD ENUF. 850 MB TEMPS BOTTOM OUT AROUND NEG 6 MIDDAY TOMORROW AND THEN START TO MODERATE. COULD BE A FAIR AMOUNT SC TOMORROW AM BUT DO EXPECT SKIES TO BECOME M/SUNNY DURING THE AFT AS SFC TO 700 MB MEAN RH FALLS TO AROUND 30 PERCENT. WILL BE CHILLY ALONG S SHORE OF LERI TOMORROW WITH NLY FLOW OFF LAKE. SUN WILL GET OFF TO A COOL START WITH HIGH PRES OVERHEAD AT DAYBREAK. HI TEMPS SUN WILL AVERAGE AROUND NORMAL WITH A LOT OF SUNSHINE. && .LONG TERM (SUN NIGHT THROUGH FRI)... EXTENDED RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE BIG PICTURE TDA. SO..FOR THE TIME BEING IT LOOKS WE SHOULD SEE A RELATIVELY QUIET EXTENDED PD WITH SPRING LIKE WX ONCE WE GET PAST THE WEEKEND. HIGH PRES WILL DIVE OVER THE WRN GRTLKS TOMORROW AND THEN BUILD ACROSS THE FORECAST AREA THRU THE START OF THE NEW WORKWEEK. HI SHOULD BE OVERHEAD SUNDAY AFT AND EVE AND THEN SHIFTS OFF TO THE EAST COAST BY MONDAY EVE. SO AFTER A COOL WEEKEND WITH TEMPS AVERAGING A LITTLE BELOW NORMAL...TEMPS WILL BEGIN TO MODERATE MON AND TUE WITH HIGH TEMPS BOTH DAYS IN THE LOWER 60S. BY EARLY WED...THERE WILL BE ENUF WAA TO POSSIBLY CAUSE A FEW SHRA OR TSRA. MORE STORMS POSSIBLE WED NIGHT INTO THU AS A COLD FRONT PASSES THRU REGION. LINGERING SHRA IN THE E ON THU IN THE CAA BEHIND THE BOUNDARY. RIDGE SLIDES ACROSS REGION THU NIGHT AND WL BACK IN WAA FLOW BY END OF PD. && .AVIATION(18Z-18Z)... THE NORTHWARD TREND OF THE WARM ADVECTION HAS NOW BEGUN TO RETREAT SOUTHWARD. AS EACH HOUR GOES BY THE NORTHERLY FLOW WILL DIMINISH OUR CHANCE OF TSTMS AND SVR WX FOR EXTREME NRN OHIO....FOR AREAS TO THE SOUTH OF CLE...JUST A LITTLE SUNSHINE IS NEEDED TO GET THE ATMOSPHERE TO DESTABILIZE EVEN FURTHER. WE WILL CONT TO MONITOR FOR WX WATCH THIS AFTN POSSIBLY FOR OUR SRN CWA. AS THE WARM FRONT RETREATS SOUTHWARD AS A COLD FRONT...THE COOLER AIR MASS WILL BRING NORTHERLY WINDS AND A SLIGT CHC OF MIXED RAIN AND SNOW SHOWERS TNGT. SOME LGT DRIZZLE WITH LOW CIGS IS A GOOD POSSIBILITY AS INDICATED ON BUFKIT SOUNDING. EXCEPT FOR SOME BRIEF VFR CONDS EARLY THIS AFTN VCNTY MFD LOOK FOR IFR OR NEAR IFR CONDS TO DOMINATE NEXT 12 TO 18 HOURS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ SHORT TERM...KUBINA/KIELTYKA LONG TERM...KUBINA AVIATION...BC oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 208 PM EDT FRI APR 7 2006 .SHORT TERM(TDY-SUN)... SFC LOW PRES NOW NEAR KERI AND CONTINUING TO MOVE OFF TO THE E. TRAILING FRONT NOW SLOWLY MOVING S AS SEEN BY LATEST SATELLITE IMAGERY. FRONT SHOULD MAKE IT AS FAR S AS KMFD BY 21Z AND BE WELL S OF THE AREA BY 00Z. LOW CLOUDS AND COOLER AIR BEHIND FNT WILL PUT AN END TO THE TSRA THREAT. FOR THE TIME BEING ONLY FAR SRN 1/3 TO 1/2 OF ZONES HAVE ANY SIGNIFICANT THREAT TO SEE T ACTIVITY AND THAT THREAT WILL RAPIDLY DIMINISH EARLY THIS EVE. LATEST NAM...RUC AND GFS FAIRLY SIMILAR WITH TIMING OF FRONT AND LOW 1ST PERIOD. VERY DRY AIR WILL FILTER IN BEHIND FRONT TONIGHT BUT VERY STRONG LLVL INVERSION TO SET UP FOR FIRST 2/3 OF THE NIGHT. COULD BE SUM SPITS OR SHRA THRU THE EARLY AM HOURS. WAS EARLIER CONCERNED ABOUT POSSIBLE FZDZ OVERNIGHT BUT NOW DRIER AIR COMES BEFORE TEMPS GET COLD ENUF. 850 MB TEMPS BOTTOM OUT AROUND NEG 6 MIDDAY TOMORROW AND THEN START TO MODERATE. COULD BE A FAIR AMOUNT SC TOMORROW AM BUT DO EXPECT SKIES TO BECOME M/SUNNY DURING THE AFT AS SFC TO 700 MB MEAN RH FALLS TO AROUND 30 PERCENT. WILL BE CHILLY ALONG S SHORE OF LERI TOMORROW WITH NLY FLOW OFF LAKE. SUN WILL GET OFF TO A COOL START WITH HIGH PRES OVERHEAD AT DAYBREAK. HI TEMPS SUN WILL AVERAGE AROUND NORMAL WITH A LOT OF SUNSHINE. && .LONG TERM (SUN NIGHT THROUGH FRI)... EXTENDED RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE BIG PICTURE TDA. SO..FOR THE TIME BEING IT LOOKS WE SHOULD SEE A RELATIVELY QUIET EXTENDED PD WITH SPRING LIKE WX ONCE WE GET PAST THE WEEKEND. HIGH PRES WILL DIVE OVER THE WRN GRTLKS TOMORROW AND THEN BUILD ACROSS THE FORECAST AREA THRU THE START OF THE NEW WORKWEEK. HI SHOULD BE OVERHEAD SUNDAY AFT AND EVE AND THEN SHIFTS OFF TO THE EAST COAST BY MONDAY EVE. SO AFTER A COOL WEEKEND WITH TEMPS AVERAGING A LITTLE BELOW NORMAL...TEMPS WILL BEGIN TO MODERATE MON AND TUE WITH HIGH TEMPS BOTH DAYS IN THE LOWER 60S. BY EARLY WED...THERE WILL BE ENUF WAA TO POSSIBLY CAUSE A FEW SHRA OR TSRA. MORE STORMS POSSIBLE WED NIGHT INTO THU AS A COLD FRONT PASSES THRU REGION. LINGERING SHRA IN THE E ON THU IN THE CAA BEHIND THE BOUNDARY. RIDGE SLIDES ACROSS REGION THU NIGHT AND WL BACK IN WAA FLOW BY END OF PD. && .AVIATION(18Z-18Z)... THE NORTHWARD TREND OF THE WARM ADVECTION HAS NOW BEGUN TO RETREAT SOUTHWARD. AS EACH HOUR GOES BY THE NORTHERLY FLOW WILL DIMINISH OUR CHANCE OF TSTMS AND SVR WX FOR EXTREME NRN OHIO....FOR AREAS TO THE SOUTH OF CLE...JUST A LITTLE SUNSHINE IS NEEDED TO GET THE ATMOSPHERE TO DESTABILIZE EVEN FURTHER. WE WILL CONT TO MONITOR FOR WX WATCH THIS AFTN POSSIBLY FOR OUR SRN CWA. AS THE WARM FRONT RETREATS SOUTHWARD AS A COLD FRONT...THE COOLER AIR MASS WILL BRING NORTHERLY WINDS AND A SLIGT CHC OF MIXED RAIN AND SNOW SHOWERS TNGT. SOME LGT DRIZZLE WITH LOW CIGS IS A GOOD POSSIBILITY AS INDICATED ON BUFKIT SOUNDING. EXCEPT FOR SOME BRIEF VFR CONDS EARLY THIS AFTN VCNTY MFD LOOK FOR IFR OR NEAR IFR CONDS TO DOMINATE NEXT 12 TO 18 HOURS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ SHORT TERM...KUBINA LONG TERM...KUBINA AVIATION...BC oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1235 PM CDT FRI APR 7 2006 .AVIATION... VFR CONDITIONS TO PREVAIL ACROSS MOST OF WEST CENTRAL TEXAS THORUGH THE PERIOD. GUSTY WEST WINDS WILL INCREASE EVEN MORE AND GRADUALLY SHIFT MORE AROUND TO THE NORTHWEST AS A COLD FRONT APPROACHES AND THEN PASSES ACROSS THE AREA. SIMILAR TO YESTERDAY...THIS MAY MEAN A BRIEF PERIOD OF BLOWING DUST AT KABI FOR A FEW HOURS LATE THIS AFTERNOON AND INTO THE EARLY EVENING. WITH THE PRESSURE GRADIENT REMAINING TIGHT...GUSTY WINDS WILL PERSIST PAST SUNSET BEFORE WEAKENING LATER THIS EVENING. && .PREV DISCUSSION... (ISSUED 631 AM CDT FRI APR 7 2006) AVIATION... EXPECT VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR THE NEXT 24 HOURS. HOWEVER...STRONG WEST TO NORTHWEST WINDS AROUND 20 KNOTS WITH GUSTS TO 35 KNOTS WILL DOMINATE WEST CENTRAL TEXAS BEGINNING LATE THIS MORNING AND CONTINUING UNTIL AROUND SUNSET THIS EVENING. LIKE YESTERDAY...BLOWING DUST MAY OCCASIONALLY REDUCE THE VISIBILITY IN SOME LOCATIONS TO AROUND 2 MILES...MAINLY ALONG AND NORTH OF INTERSTATE 20 THIS AFTERNOON. THIS EVENING...A STRONG COLD FRONT WILL PUSH SOUTH ACROSS WEST CENTRAL TEXAS AND SHIFT WINDS TO THE NORTH. AFTER MIDNIGHT TONIGHT...EXPECT NORTH WINDS AROUND 10 KNOTS ACROSS WEST CENTRAL TEXAS. PREV DISCUSSION... (ISSUED 331 AM CDT FRI APR 7 2006) SHORT TERM... LOOKS LIKE ONE MORE DAY OF WARM AND WINDY CONDITIONS AS A LOW PRESSURE SYSTEM SLOWLY PULLS OUT OF THE PLAINS TODAY. SFC DRYLINE REMAINS STALLED ACROSS CENTRAL TX ALONG I-35 THIS MORNING. THE DRYLINE SHOULD MAKE SOME MORE EASTWARD PROGRESS TODAY AS SFC LOW PRESSURE IN S NEBRASKA PUSHES EAST. GFS/NAM 00Z INITIALIZATIONS SEEM NOT TO RESOLVE A DEEP ENOUGH LOW PRESSURE WHICH MAY RESULT IN A WEAKER PRESSURE GRADIENT AND WINDS OVER THE REGION. THE 06Z RUC SEEMS TO HAVE A BETTER HANDLE ON THIS WHICH SUPPORTS STRONGER WINDS IN THE 25-30KT RANGE LATE THIS MORNING. ALSO ANOTHER POTENT SHORTWAVE LOCATED OVER THE ROCKIES SHOULD DIVE INTO THE BOTTOM OF THE UPPER TROUGH OVER THE PLAINS. THIS SHORTWAVE MAY ALSO AID IN TIGHTENING THE PRESSURE GRADIENT AS WELL. FEEL PRESSURE GRADIENT WILL BE TIGHT ENOUGH TO SUPPORT STRONG WINDS SO WIND ADVISORY IS NEEDED FOR BIG COUNTRY...CONCHO VALLEY AND HEARTLAND. WITH DRY AIR IN PLACE...ALSO NEED RED FLAG WARNING FOR ALL AREAS. WINDS SHOULD EXCEED CRITERIA ESPECIALLY IN THE BIG COUNTRY AND RELATIVE HUMIDITY SHOULD BE BELOW 20 PERCENT. DESPITE THE POOR INITIALIZATION OF THE NAM...MODELS CONTINUE TO SUGGEST A STRONG COLD FRONT TO PUSH THROUGH FRI NIGHT WITH THE NAM THE COLDEST BETWEEN IT AND THE GFS. COLD ADVECTION SHOULD CONTINUE MOST OF SATURDAY WHICH WILL HOLD TEMPERATURES INTO THE UPPER 60S TO LOW 70S FOR MOST AREAS. LOW TEMPS WILL FALL BACK INTO THE 40S. UPPER LEVEL RIDGING SHOULD SPREAD OVER THE AREA THROUGH THE WEEKEND AS ANOTHER UPPER TROUGH DIGS OFF THE CALIFORNIA COAST. EARLY NEXT WEEK SFC HIGH PRESSURE SHOULD SHIFT EAST ALLOWING FOR SOME RETURN FLOW OFF THE GULF. WITH THE FRONT PUSHING WELL INTO THE GULF...MOISTURE SHOULD BE SLOW TO RETURN. LONG TERM... EARLY NEXT WEEK GFS/ECMWF AGREE WITH ONE INITIAL SHORTWAVE TROUGH SCREAMING INTO THE PLAINS ON MONDAY WITH MEAN TROUGH SITUATED OFF THE CALIFORNIA COAST. MODELS SEEM QUITE CONTENT TO KEEP A MEAN TROUGH OFF THE CALIFORNIA COAST THROUGH MUCH OF NEXT WEEK WHICH KEEPS UPPER RIDGING OVER MUCH OF THE PLAINS. EXPECT TEMPERATURES TO REBOUND WELL INTO THE 80S FOR MAX TEMPS DURING THE WEEK. FORECASTED TEMPS ARE CLOSE TO GUIDANCE...BUT A PERHAPS A COUPLE OF DEGREES WARMER ON MAX TEMPS AS LOW LEVEL FLOW WILL MAINLY BE FROM THE SOUTH AND SOUTHWEST. THIS MAY ALLOW FOR ESTABLISHED ELEVATED MIX LAYER TO MIX DOWN RESULTING IN WARMER TEMPS THAN WHAT GUIDANCE SUGGESTS. WILL TRY NOT TO GET TOO CARRIED AWAY AS THERE IS GOOD AGREEMENT WITH GFS ENSEMBLE MOS NUMBERS...BUT STILL THINK TEMPS COULD WARM INTO THE UPPER 80S ESPECIALLY TOWARDS MID WEEK. RAIN CHANCES LOOK SLIM TO NONE AS ANY SHORTWAVE TROUGHS LOOK TO PUSH INTO THE CENTRAL PLAINS AND ATMOSPHERE SHOULD BE SUFFICIENTLY CAPPED BY ELEVATED MIXED LAYER WITH 700MB TEMPS RUNNING 8C-10C. THIS WILL ALSO BE AIDED BY THE FACT THAT MOISTURE WILL BE SLOW TO RETURN AND WILL BE SHALLOW AT BEST ESPECIALLY IN THE BEGINNING OF THE WEEK. SJT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 11 AM FRIDAY TO 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO... CROCKETT...FISHER...HASKELL...IRION...JONES...KIMBLE...MASON... MCCULLOCH...MENARD...NOLAN...RUNNELS...SAN SABA...SCHLEICHER... SHACKELFORD...STERLING...SUTTON...TAYLOR...THROCKMORTON...AND TOM GREEN. WIND ADVISORY FROM 11 AM FRIDAY TO 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO...FISHER... HASKELL...IRION...JONES...MCCULLOCH...NOLAN...RUNNELS...SAN SABA...SHACKELFORD...STERLING...TAYLOR...THROCKMORTON...AND TOM GREEN. $$ && .SJT WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO...CROCKETT...FISHER... HASKELL...IRION...JONES...KIMBLE...MASON...MCCULLOCH...MENARD... NOLAN...RUNNELS...SAN SABA...SCHLEICHER...SHACKELFORD... STERLING...SUTTON...TAYLOR...THROCKMORTON...AND TOM GREEN. WIND ADVISORY UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES: BROWN... CALLAHAN...COKE...COLEMAN...CONCHO...FISHER...HASKELL...IRION... JONES...MCCULLOCH...NOLAN...RUNNELS...SAN SABA...SHACKELFORD... STERLING...TAYLOR...THROCKMORTON...AND TOM GREEN. && $$ 07 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 1131 AM CDT FRI APR 7 2006 .UPDATE... POTENT LOW OVER CENTRAL KANSAS CONTINUES TO SLIDE SOUTHWARD TOWARD OKLAHOMA. ALSO A COLD FRONT STRETCHING ACROSS THE TEXAS PANHANDLE IS EXPECTED TO MOVE SOUTH ACROSS THE SOUTH PLAINS DURING THE AFTERNOON. PRESSURE GRADIENT HAS TIGHTENED ACROSS THE REGION WITH MANY OF THE TEXAS TECH MESONET SITES REPORTING WINDS IN ADVISORY CRITERIA. LATEST RUC ALSO INDICATES WINDS TO STAY UP THROUGH THE AFTERNOON WHILE SHIFTING TO THE NORTHWEST AND NORTH BEHIND FRONTAL PASSAGE. HAVE UPDATED WIND ADVISORY TO INCLUDE ALL OF THE FORECAST AREA FOR THE AFTERNOON. WILL SEND UPDATED GRIDS AND ZONES ASAP. && .PREV DISCUSSION... (ISSUED 314 AM CDT FRI APR 7 2006) SHORT TERM... ANOTHER WINDY DAY IN STORE FOR FRIDAY AS THE CLOSED LOW OVER EASTERN NEBRASKA THIS MORNING WILL BE SLOW TO PULL OUT AND FLOW AROUND IT WILL DOMINATE THE REGION. GUIDANCE TAKES THE LOW SE INTO EASTERN OKLA DURING THE DAY WITH STRONG NWERLY WINDS EXTENDING ACROSS WESTERN OKLA AND INTO WTX. ADDITIONALLY...A COLD FRONT LOCATED ACROSS NE COLO AND NW KS AT 07Z WILL MOVE SOUTH INTO THE NRN CWA BY LATE MORNING AND BRING A WIND SHIFT FROM THE NW TO THE NORTH AND WILL BE ACCOMPANIED BY ANOTHER INCREASE IN WIND SPEED...COOLER TEMPS... SLIGHTLY MORE MOIST AIR...AND PERHAPS LOW CLOUDS...ESPECIALLY ACROSS THE NRN ROLLING PLAINS. THERE IS A LARGE DIFFERENCE BETWEEN MAV/MET HIGH TEMPS FOR TODAY...ALTHOUGH TIMING OF THE FRONT APPEARS TO BE SIMILAR. HAVE TRENDED SLIGHTLY TOWARD THE COOLER MET AS FRONT AND COOL AIR LOOK IMPRESSIVE ACROSS NE COLO/SRN NEBRASKA THIS MORNING. IF FRONT IS SLIGHTLY SLOWER THAN EXPECTED THE WARMER MAV NUMBERS WILL PROBABLY VERIFY. REGIONAL PROFILER ANALYSIS SHOWS 50 KTS AROUND 700 MB STRETCHING FROM NE NEW MEXICO INTO CENTRAL OKLA. THIS BAND SHOULD SLOWLY SHIFT SE THROUGH THE DAY AND WILL LIKELY PUT THE NRN AND CENTRAL ROLLING PLAINS UNDER THE GUN FOR THE LONGEST PERIOD OF TIME FOR STRONG WINDS. THUS WILL ISSUE A WIND ADVISORY FOR THIS AREA FROM 10 AM TO 7 PM CDT BUT HOLD OFF ELSEWHERE. WIND SPEEDS WILL APPROACH ADVISORY CRITERIA ACROSS MOST OF THE NORTHERN COUNTIES ONCE MIXING COMMENCES THIS MORNING BUT HOPEFULLY THEY WILL ONLY PUSH CRITERIA BRIEFLY BEFORE TEMPORARILY RELAXING UNTIL FROPA. GUIDANCE ALSO HINTS AT THE POSSIBILITY OF A LOW CLOUD FIELD MOVING IN BEHIND THE FRONT ALONG WITH INCREASED LOW LEVEL MOISTURE. HAVE UPPED SKY COVER ACROSS THE ROLLING PLAINS FOR THIS EVE THRU TONIGHT. LONG TERM... RIDGING ALOFT THIS WEEKEND SHIFT EWD AS TROUGH OVER THE PACIFIC COAST DEVELOPS FURTHER. SWLY FLOW ALOFT MONDAY THROUGH THURSDAY WITH TROUGH WELL BACK TO OUR WEST WILL NOT BE FAVORABLE FOR PRECIP GENERATION. SHOULD SEE THE DRYLINE REDEVELOP MONDAY AND THEN SPEND THE NEXT FEW DAYS SLOSHING ACROSS AREAS EAST OF THE CAPROCK AND FURTHER EAST INTO NW TEXAS. HOWEVER CHANCES OF CONVECTIVE INITIATION APPEAR SMALL GIVEN EXPECTED STRENGTH OF THE CAP. FOR TEMPS...NUMERICAL GUIDANCE LOOKS FINE. FEW CHANGES MADE TO THE FCST. FIRE WEATHER... WIND SPEEDS SHOULD BE MAXIMIZED ACROSS THE NORTHERN AND EASTERN HALF OF THE CWA WHILE A DECENT NORTH-SOUTH TEMP GRADIENT (AND A LONGER PERIOD OF DRY WESTERLY FLOW) SHOULD PRODUCE THE LOWEST RH/S ACROSS THE SRN HALF. WILL ISSUE A RED FLAG WARNING FOR THE SRN HALF FROM 11 AM TO 7 PM CDT. DESPITE THE FCST OF 20-FT WIND TO ONLY MARGINALLY MEET THE SPEED AND TEMPORAL CRITERIA...THE CONTINUING VERY DRY CONDITIONS AND IMPENDING FRONTAL PASSAGE DURING THE AFTERNOON WILL PRODUCE CONDITIONS FAVORABLE FOR DANGEROUS FIRE BEHAVIOUR. HAVE DROPPED THE NRN ROW OF COUNTIES FROM THE FIRE WX WATCH AS IT APPEARS THAT THE COOLER AND MORE MOIST AIR BEHIND THE FRONT WILL INCREASE RH VALUES DURING THE AFTN...HOWEVER WITH THE STRONG WINDS FIRE DANGER ACROSS THE NORTHERN COUNTIES WILL REMAIN ELEVATED. && .LUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES: COCHRAN...CROSBY...DICKENS...GARZA...HOCKLEY...KENT...KING... LUBBOCK...LYNN...STONEWALL...TERRY...AND YOAKUM. WIND ADVISORY UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES: BAILEY...BRISCOE...CASTRO...CHILDRESS...COCHRAN...COTTLE... CROSBY...DICKENS...FLOYD...GARZA...HALE...HALL...HOCKLEY... KENT...KING...LAMB...LUBBOCK...LYNN...MOTLEY...PARMER... STONEWALL...SWISHER...TERRY...AND YOAKUM. && $$ 08 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 300 PM EDT FRI APR 7 2006 .SHORT TERM /REST OF TONIGHT THROUGH SUNDAY/... STORMS CONTINUING TO FORM ALONG OLD BOUNDARY FROM MORNING ACTIVITY. CONVECTIVE PARAMETERS ACROSS CENTRAL CWA ARE NOT TOO IMPRESSIVE...SO NOT TOO CONCERNED ABOUT SEVERE STORMS FROM THIS ACTIVITY. POTENTIAL INCREASING FOR SEVERE WEATHER ACROSS WESTERN HALF OF CWA. SPC ABOUT TO DROP A WATCH ACROSS THIS AREA...AS BUILDING INSTABILITY COMBINES WITH A STRENGTHENING LOW-LEVEL JET AND DEEP LAYER SHEAR. HAVE LIKELY POPS DURING THE EARLY EVENING FOR THIS ACTIVITY...MAY NEED TO BE BUMPED UP SOON. INCLUDING STRONG HAIL/WIND WORDING FOR SEVERE POTENTIAL. LATER ACTIVITY IN 03Z-12Z TIMEFRAME WILL FOCUS ON FRONTAL BOUNDARY DROPPING SOUTHEAST ACROSS CWA...AS ACTIVITY WILL BE FED BY LOW LEVEL JET INTO FRONT. TRIED TO TIME PASSAGE IN THE HOURLY POP FIELDS. KEEPING WIND/HAIL WORDING ALONG FRONT BUT NON-SEVERE. LOW TEMPS GENERALLY WENT TOWARD COOLER SIDE OF MOS...GIVEN STRENGTH OF FRONT AND FAIRLY RAPID TEMPERATURE DROP BEHIND IT. PRECIP WILL HANG ON IN THE SOUTHEASTERN PART OF THE CWA...WITH AN AREA OF LOW PRESSURE RIDING ALONG THE FRONT SATURDAY MORNING. SOUTHEASTERN OHIO WILL SEE THE MOST SUNSHINE SATURDAY...WITH CLOUDS ELSEWHERE...UNTIL SOME CLEARING IN THE AFTERNOON. ONLY A FEW TWEAKS TO MAX TEMPS. HIGH PRESSURE CONTINUES TO BUILD EAST SATURDAY NIGHT...ALLOWING FOR SKIES TO CLEAR. WITH A GRADIENT LEFT FOR PART OF THE NIGHT...WENT A FEW DEGREES WARMER THAN GUIDANCE. DISREGARDED THE COLDER FWC NUMBERS FOR SUNDAY HIGHS...AND LEFT HIGHS AS IS...WHICH IS BASICALLY SPLIT DOWN THE MIDDLE BETWEEN THE COLDER FWC AND WARMER MAV...AS H85 ADJUSTMENTS INDICATE MIDDLE TO UPPER 50S WITH FULL SUNSHINE. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL RIDGE DOMINATES THE EASTERN HALF OF THE NATION THIS PERIOD...WITH GENERALLY DRY WEATHER...AND A FAIRLY LARGE DIURNAL TEMPERATURE RANGE DUE TO THE DRY AIR. LOOK FOR WARM DAYTIME AND COOL NIGHTTIME TEMPERATURES. ONLY SYSTEM OF CONSEQUENCE FOR US THIS PERIOD WILL BE AN UPPER TROUGH AND COLD FRONT THAT COMES INTO THE PACIFIC COAST MONDAY...THEN WEAKENS CONSIDERABLY AS THE SYSTEM TRIES TO CROSS THE UPPER RIDGE TUESDAY AND WEDNESDAY. BY THE TIME IT REACHES US...ALL THAT REMAINS IS A WEAK UPPER DISTURBANCE...AND A WEAK COOL FRONT THAT MAY NOT EVEN MAKE IT TO OUR REGION. THE GFS STILL APPEARS TOO AGGRESSIVE AND FAST WITH THIS SYSTEM BEATING DOWN THE UPPER RIDGE...THOUGH THE TREND WITH EACH RUN IS TO WEAKEN THE SYSTEM AS THE EURO MODELS HAVE BEEN DOING. THUS...EXPECT MAINLY CLOUDS AND A FEW SHOWERS WITH THIS SYSTEM LATER WEDNESDAY INTO THURSDAY. && .PREV DISCUSSION... /ISSUED 144 PM EDT FRI APR 7 2006/ AVIATION... SCT-BKN LINE OF CONVECTION FORMING ALONG BOUNDARY LEFT BY MORNING ACTIVITY. THIS LINE SHOULD MOVE EAST BY 21-22Z OR SO. THE TAF SITES SHOULD ESCAPE THE MOST ADVERSE EFFECTS EARLY ON. COLD FRONTAL PASSAGE EXPECTED IN THE 03Z-10Z TIMEFRAME ACROSS THE RLX CWA. TRIED TO TIME THIS PASSAGE IN TAFS...USING TEMPOS TO INDICATE A TWO HOUR IFR TSRA WINDOW ALONG AND JUST AHEAD OF THE FRONT. WILL NEED TO FINE-TUNE THIS AS TIME GOES ON...ESPECIALLY IF SEVERE THREAT INCREASES. LEFT IN A FEW HOURS OF POST-FRONTAL SHRA WITH MVFR CIGS/VIS. THINK CIGS WILL REMAIN MVFR THROUGH AT LEAST 18Z AREAWIDE BEFORE IMPROVEMENT THEREAFTER. PREV DISCUSSION... /ISSUED 1024 AM EDT FRI APR 7 2006/ SHORT TERM /REST OF TODAY/... LAST OF MORNING SHRA/TSRA POISED TO EXIT NE CORNER OF CWA. SOME WEAKENING HAS BEEN OCCURRING AS NOCTURNAL LOW LEVEL JET WEAKENS. CWA WILL ENJOY A BRIEF BREAK FROM PRECIPITATION UNTIL LATER THIS AFTERNOON. FOCUS NOW SHIFTS TO CONVECTION EXPECTED AFTER 21Z OR SO. LOOKING LIKE A BAND WILL BE FOCUSED ALONG APPROACHING FRONT...FED BY LOW LEVEL CONVERGENCE. THIS ZONE WILL BE BACK NEAR CMH AROUND 00Z...DROPPING TO NEAR A HTS/CKB LINE BY 03Z...AND APPROACHING BKW BY 06Z. ANOTHER POSSIBLE FOCUSING MECHANISM WILL BE BOUNDARY LAID DOWN BY CONVECTION THIS MORNING FROM CVG TO PKB. RUC SEEMS TO PICK UP ON THIS. THIS IS EVIDENT ON SURFACE OBS...WITH 55 DEGREES AT PKB AND 71 AT CRW AT 14Z. COULD SEE SOME EARLIER DEVELOPMENT HERE AS INSTABILITY BUILDS. FOR NOW...BETTING ON LATER BOUNDARY TO BE THE MAIN FOCUS...AND AS SUCH KEPT LATER POPS THE WAY THEY WERE. REDUCED POPS BEFORE 18Z AS IT WILL TAKE A FEW HOURS FOR INSTABILITY TO BUILD. UPPED HIGH TEMPS ACROSS SOUTHERN PART OF REGION...AND DROPPED THEMA BIT IN RAIN COOLED AREA. PLENTY TO MONITOR THIS AFTERNOON. PREV DISCUSSION... /ISSUED 422 AM EDT FRI APR 7 2006/ LONG TERM /SATURDAY THROUGH THURSDAY/... HAVE SHRUNK THE LINE BETWEEN PRECIPITATION AND DRY WEATHER SATURDAY...AS IT CONTINUES TO BE EVIDENT THAT LITTLE SHOULD OCCUR BEHIND THE THIN LINE OF CONVECTION THAT WILL CROSS OVERNIGHT TONIGHT. OUR LARGE AREA OF LOW PRESSURE...WILL BE REPLACED BY A LARGE AREA OF HIGH PRESSURE ACROSS THE CENTRAL AND EASTERN U.S. THROUGH TUESDAY. THE SFC HIGH SHOULD BE OVERHEAD SUNDAY NIGHT INTO MONDAY MORNING. AS FOR THE CHANCE FOR PRECIPITATION THROUGH THE REMAINDER OF THE TIME PERIOD...DID NOT ADD ANYTHING TO OUR DRY PATTERN THAT WILL SET UP THROUGH AT LEAST TUESDAY. ANOTHER CHANGE WILL BE THE RETURN OF LIGHTER WINDS THAT WE ARE MORE USE TO...AS HIGH PRESSURE DOMINATES. NO EDITS WERE DONE TO THE FORECAST PAST TUESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...CL/KM LONG TERM...JMV wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 144 PM EDT FRI APR 7 2006 .AVIATION... SCT-BKN LINE OF CONVECTION FORMING ALONG BOUNDARY LEFT BY MORNING ACTIVITY. THIS LINE SHOULD MOVE EAST BY 21-22Z OR SO. THE TAF SITES SHOULD ESCAPE THE MOST ADVERSE EFFECTS EARLY ON. COLD FRONTAL PASSAGE EXPECTED IN THE 03Z-10Z TIMEFRAME ACROSS THE RLX CWA. TRIED TO TIME THIS PASSAGE IN TAFS...USING TEMPOS TO INDICATE A TWO HOUR IFR TSRA WINDOW ALONG AND JUST AHEAD OF THE FRONT. WILL NEED TO FINE-TUNE THIS AS TIME GOES ON...ESPECIALLY IF SEVERE THREAT INCREASES. LEFT IN A FEW HOURS OF POST-FRONTAL SHRA WITH MVFR CIGS/VIS. THINK CIGS WILL REMAIN MVFR THROUGH AT LEAST 18Z AREAWIDE BEFORE IMPROVEMENT THEREAFTER. && .PREV DISCUSSION... /ISSUED 1024 AM EDT FRI APR 7 2006/ SHORT TERM /REST OF TODAY/... LAST OF MORNING SHRA/TSRA POISED TO EXIT NE CORNER OF CWA. SOME WEAKENING HAS BEEN OCCURRING AS NOCTURNAL LOW LEVEL JET WEAKENS. CWA WILL ENJOY A BRIEF BREAK FROM PRECIPITATION UNTIL LATER THIS AFTERNOON. FOCUS NOW SHIFTS TO CONVECTION EXPECTED AFTER 21Z OR SO. LOOKING LIKE A BAND WILL BE FOCUSED ALONG APPROACHING FRONT...FED BY LOW LEVEL CONVERGENCE. THIS ZONE WILL BE BACK NEAR CMH AROUND 00Z...DROPPING TO NEAR A HTS/CKB LINE BY 03Z...AND APPROACHING BKW BY 06Z. ANOTHER POSSIBLE FOCUSING MECHANISM WILL BE BOUNDARY LAID DOWN BY CONVECTION THIS MORNING FROM CVG TO PKB. RUC SEEMS TO PICK UP ON THIS. THIS IS EVIDENT ON SURFACE OBS...WITH 55 DEGREES AT PKB AND 71 AT CRW AT 14Z. COULD SEE SOME EARLIER DEVELOPMENT HERE AS INSTABILITY BUILDS. FOR NOW...BETTING ON LATER BOUNDARY TO BE THE MAIN FOCUS...AND AS SUCH KEPT LATER POPS THE WAY THEY WERE. REDUCED POPS BEFORE 18Z AS IT WILL TAKE A FEW HOURS FOR INSTABILITY TO BUILD. UPPED HIGH TEMPS ACROSS SOUTHERN PART OF REGION...AND DROPPED THEMA BIT IN RAIN COOLED AREA. PLENTY TO MONITOR THIS AFTERNOON. PREV DISCUSSION... /ISSUED 422 AM EDT FRI APR 7 2006/ SHORT TERM /REST OF TODAY THROUGH TONIGHT/... WARM FRONT TO OUR NORTH IS EVIDENT ON SFC OBS DEWPOINT DISCONTINUITY. RADAR SHOWS LIGHT RAIN SHOWERS MOVING MAINLY EAST...MORE NUMEROUS ACROSS THE NORTHERN HALF OF WEST VIRGINIA AND SOUTHEAST OHIO. VERY ISOLATED THUNDERSTORMS COULD BE POSSIBLE AS THEY MOVE INTO SOUTHEAST OHIO...BUT WILL BE SHORT LIVED THIS MORNING. NAM AND LOCAL WRF MODELS SHOWING DESCENT MUCAPE OF NEAR 2500 J/KG... LOW LEVEL MOIST CONVERGENCE...AND LIFTED INDEX OF -4 C...SUGGEST POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND EVENING ACROSS SOUTHEAST OHIO...ACROSS NORTHERN WEST VIRGINIA AND ALONG THE OHIO RIVER IN WEST VIRGINIA. SPC HAS THIS AREA UNDER A SLIGHT RISK FOR SEVERE WEATHER TODAY AND TONIGHT. INCLUDED STRONG GUSTY WINDS AND SMALL HAIL WITH THUNDERSTORMS ACROSS THE WEST AND NORTH. SOUTHERLY WEAK FLOW WILL BECOME GENTLE FROM THE SOUTHWEST BY MID MORNING AND STRONG AND GUSTY FROM THE WEST SOUTHWEST THIS AFTERNOON. COLD FRONT IS EXPECTED TO MOVE THRU THE AREA AROUND 06Z TONIGHT. WARM TEMPERATURES TODAY WILL REACH THE MID TO UPPER 70S LOWLANDS...RANGING TO LOWER 60S OVER HIGHER TERRAIN IN THE NORTHERN MOUNTAINS. TWEAKED LOCAL MOS TEMPS FOR HIGHS TODAY...AND WENT CLOSE TO MAV NUMBERS FOR LOWS TONIGHT. LONG TERM /SATURDAY THROUGH THURSDAY/... HAVE SHRUNK THE LINE BETWEEN PRECIPITATION AND DRY WEATHER SATURDAY...AS IT CONTINUES TO BE EVIDENT THAT LITTLE SHOULD OCCUR BEHIND THE THIN LINE OF CONVECTION THAT WILL CROSS OVERNIGHT TONIGHT. OUR LARGE AREA OF LOW PRESSURE...WILL BE REPLACED BY A LARGE AREA OF HIGH PRESSURE ACROSS THE CENTRAL AND EASTERN U.S. THROUGH TUESDAY. THE SFC HIGH SHOULD BE OVERHEAD SUNDAY NIGHT INTO MONDAY MORNING. AS FOR THE CHANCE FOR PRECIPITATION THROUGH THE REMAINDER OF THE TIME PERIOD...DID NOT ADD ANYTHING TO OUR DRY PATTERN THAT WILL SET UP THROUGH AT LEAST TUESDAY. ANOTHER CHANGE WILL BE THE RETURN OF LIGHTER WINDS THAT WE ARE MORE USE TO...AS HIGH PRESSURE DOMINATES. NO EDITS WERE DONE TO THE FORECAST PAST TUESDAY. PREV DISCUSSION... /ISSUED 155 AM EDT FRI APR 7 2006/ AVIATION... LATEST SFC OBS SHOW DEWPOINT WARM FRONT ALREADY NORTH OF PKB AND EKN. RADAR SHOWS RAIN SHOWERS MOVING EAST NORTHEAST MAINLY ACROSS THE NORTHERN HALF OF THE AREA...TO AFFECT PKB...CKB...EKN ON AND OFF THRU AT LEAST 10Z. ADDITIONAL LIGHT SHOWERS COULD STILL AFFECT THE SOUTHERN SITES...CRW...HTS...AND BKW SO INCLUDE RAIN IN A TEMPO OVERNIGHT. VFR CONDITIONS FOR THE MOST PART WITH OCCASIONALLY MVFR/IFR VISIBILITIES AND CEILINGS WITHIN RAIN SHOWERS. COLD FRONT IS EXPECTED TO AFFECT THE AREA FROM WEST TO EAST AND BRING THUNDERSTORMS TO THE AREA TONIGHT AROUND 03-06Z SAT. WILL HAVE A CLOSER TIMING ON NEXT TAF ISSUANCE. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ AVIATION...CL wv