AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 330 AM MST TUE MAR 8 2005 .SHORT TERM... (TODAY AND TONIGHT) ...WINDY-VERY WINDY CONDITIONS ANTICIPATED THIS AFTN FOR SERN CO... CURRENTLY...WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES SHOWED A 100-120KT ULJ DRIVING THROUGH WRN MT. THIS IS A LITTLE FURTHER W THAN MODELS DEPICTED YESTERDAY. IF THIS TRAJECTORY HOLDS... THEN IT WILL HAVE SOME AFFECTS ON TODAY'S FORECAST. IR SATELLITE IMAGERY...SFC WEATHER DEPICTION DATA...AND NATIONAL RADAR SHOWING CONVECTIVE PRECIPITATION(E.G. SHOWERS) OCCURRING EARLY THIS MORNING...SO DYNAMIC ASCENT ALREADY SHOWING THE SYSTEM'S STRENGTH. SFC WINDS HAVE STEADILY PICKED ACROSS SRN WY IN RESPONSE TO FALLING PRESSURE AND TERRAIN. TODAY...WILL NEED TO MAKE SOME MODIFICATIONS TO THE CURRENT 12-18 HOUR FORECAST. ALL SHORT RANGE MODELS PROJECTING THE 100-120KT ULJ "BUCKLING" A LITTLE FURTHER WEST INTO CO. THIS IS IMPORTANT AS IT PLACES AT LEAST ERN 1/2 OF CO IN A MORE FAVORED SYNOPTIC SCALE ASCENT REGIME GIVEN JET/THERMAL DYNAMICS ANALYSES. ALSO...THE SYSTEM WILL BE MOVING THROUGH CO DURING THE PEAKING HEATING HOURS...SO SURFACE AS WELL AS MID LEVEL LAPSE RATES SHOULD BECOME FAIRLY STEEP. THE BEST SYNOPTIC SCALE ASCENT "WINDOW" APPEARS TO BE BETWEEN 18Z-01Z FOR THE ERN CO MTS/PLAINS. SFC TEMPS SHOULD BE ALLOWED TO WARM INTO THE 40S/50S JUST BEFORE THE WEATHER SYSTEM GETS INTO THE FORECAST AREA. THERE WILL STILL LIKELY BE SOME INITIAL STRONG EVAPORATIVE COOLING OCCURRING. HOWEVER...WITH SUCH MODERATE-STRONG MID LEVEL LAPSE RATES...THE PRECIPITATION SHOULD BE ABLE TO ACCUMULATE ON THE GROUND LATER IN THE DAY. ALL NECESSARY FEATURES APPEAR TO BE JUXTAPOSED FOR A WINDY-VERY WINDY AFTN ACROSS ERN CO. WITH ULJ NEARLY DIRECTLY OVERHEAD...STEEP LAPSE RATES...ENOUGH MOISTURE...AND EVAPORATIVE COOLING...THE DOWNWARD MOMENTUM FROM THE SHOWERS SHOULD ALLOW FOR MID LEVEL WINDS TO REACH THE SURFACE. SFC WIND GUSTS COULD REACH 45KTS LATER THIS AFTERNOON WITH THE FRONTAL BOUNDARY SURGE INDUCED BY THE PRECIPITATION. WOULD NOT BE SURPRISED TO SEE A 50KT GUST...BUT DO NOT THINK IT WILL BE WIDESPREAD ENOUGH TO MENTION. THERE HAS NOT BEEN MUCH IN THE WAY OF SIGNIFICANT PRECIPITATION ACROSS SERN CO THE LAST FEW MONTHS. BLOWING DUST WILL BE LIKELY...IF THE WINDY-VERY WINDY CONDITIONS DEVELOP. GIVEN THE STEEP LAPSE RATES...THERE COULD BE SOME SNOW ACCUMULATIONS MAINLY AT AND ABOVE 7K FT MSL...ESPECIALLY IN TELLER COUNTY AND THE PALMER DIVIDE. PIKES PEAK COULD EVEN GET 2-4 INCHES BY THIS AFTERNOON. TONIGHT...MUCH OF THE SIGNIFICANT WEATHER SHOULD BE OVER DURING THE EARLY EVENING HOURS. SURFACE WINDS WILL BE DIMINISHING BY MID EVENING WITH A CLEARING SKY AND MORE TRANQUIL WEATHER BY THE OVERNIGHT HOURS. [METZE] .LONG TERM... (WEDNESDAY THROUGH NEXT MONDAY) WEATHER ISSUES OF THE LONG TERM CYCLE APPEARS TO BE INCREASING PRECIPITATION CHANCES AND COOLER TEMPERATURES AREA-WIDE BY VERY LATE IN THE WEEKEND INTO NEXT WEEK. FOR WEDNESDAY...LATEST MODELS INDICATE THAT DRY NORTHERLY FLOW ALOFT DOMINATES THE WEATHER SCENE OVER CWFA WHILE STRONG UPPER RIDGE DEVELOPS OVER SOUTHERN CALIFORNIA...UPPER FLOW THEN BECOMES NORTHWESTERLY WEDNESDAY NIGHT INTO THE WEEKEND WITH ANOTHER JET MAX ROTATING ACROSS REGION FROM LATER THURSDAY INTO FRIDAY...WHILE STRONG UPPER RIDGE REMAINS IN PLACE FROM NORTHERN CALIFORNIA INTO SOUTHERN ARIZONA. FROM SUNDAY NIGHT INTO NEXT TUESDAY UPPER FLOW ACROSS CWFA BECOMES MORE WESTERLY AS DEEP CLOSED UPPER LOW DEVELOPS OVER THE ONTARIO PROVINCE OF CANADA. MODELS DO SUGGEST THAT CHANCES OF PRECIPITATION WILL BE INCREASING OVER CWFA FROM LATE SUNDAY INTO EARLY NEXT WEEK AND WILL DEPICT THIS IN IMPENDING GRIDS/ZONES. EXPECT THAT THE WARMEST TEMPERATURES OF THE LONG TERM WILL BE NOTED FROM FRIDAY INTO SUNDAY...WHILE COOLEST TEMPERATURES ARE PROJECTED BY NEXT TUESDAY. THANKS SURROUNDING OFFICES FOR COORDINATION/COLLABORATION. && .PUB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 355 AM CST TUE MAR 8 2005 .SYNOPSIS... SWATH OF LOW CLOUDS AND FLURRIES FOUND OVER ALL BUT THE NORTHEAST AND FAR SOUTHWEST COUNTIES ATTIM. DVN WSR-88D SHOWS SOME ENHANCED MESOSCALE BANDS ROUGHLY 10-15 MI WIDE MAINLY FROM NEAR CEDAR RAPIDS TO MUSCATINE TO MONMOUTH WITH POTENTIAL FOR DUSTING TO FEW TENTHS OF AN INCH OF ACCUMULATION. THIS BAND IS OCCURRING RIGHT ALONG SFC CONVERGENCE ZONE. SOME SYNOPTIC SCALE LIFT NOTED WITH H5 TROUGH AND LIFT FROM LFQ OF H3 100-110 KT JET. ETA/NAM ALSO SHOWS SOME OMEGA IN THE 1000-850 MB LAYER. TEMPS VARY FROM M/U20S BENEATH CLOUDS TO AROUND 20 DEGS WHERE SKIES ARE CLEAR. ..05.. && .SHORT TERM...(TODAY AND TONIGHT) RUC 1000-850 MB RELH PROG MATCHES WELL WITH CURRENT CLOUD TRENDS AND FOLLOWED CLOSELY. SFC CONVERGENCE ZONE BETWEEN MLI AND BRL TO SAG SOUTH OF THE AREA BY AFTERNOON. WILL HAVE MENTION OF FLURRIES UNTIL MID MORNING BENEATH CLOUDS AND USE NOWCAST TO HANDLE MESOSCALE BAND WITH MINOR ACCUMS. CLOUD FREE AREAS LIKELY TO FILL IN WITH STRATOCU MID MORNING. BUT OVERALL INCREASING SUBSIDENCE AND MUCH DRIER AIR ADVECTING IN ON NORTH WINDS SHOULD BRING CLEARING SKIES FROM NORTH TO SOUTH LATE MORNING AND THROUGH THE AFTERNOON. WITH THE ANTICIPATION OF MOST AREAS MOSTLY SUNNY BY MID AFTERNOON WILL KEEP WITH THE TREND OF LATE OF GOING ABOVE GUIDANCE. TONIGHT...MAIN CONCERN IS HOW LOW TO GO ON MIN TEMPS. CLIPPER SYSTEM DIVING E/SE THROUGH NORTHERN ROCKIES ATTIM WILL STAY WELL TO OUR WEST. REMOVED PCPN IN THE FAR SOUTHWEST. WEAK MID LEVEL LIFT NOTED IN THE SOUTHWEST FROM SOME OF THE MODELS...BUT NOT ENOUGH FOR EVEN FLURRIES WITH COPIOUS AMOUNTS OF DRY AIR TO OVERCOME FROM SFC-750 MB. JUST INCREASE IN MID/HIGH CLOUDS ESP THE SOUTH/WEST COUNTIES. THUS EXPECT TEMP GRADIENT FROM NORTHEAST TO SOUTHWEST...WITH WARMEST READINGS IN THE SOUTHWEST WHERE MORE CLOUDS AND COLDEST IN THE NORTHEAST WHERE FEWER CLOUDS AND LOTS OF DRY AIR. DIDN/T GO QUITE AS COLD AS GUIDANCE (SINGLE DIGITS) IN THE NORTHEAST GIVEN 1) TIME OF YEAR 2) DRY GROUND AND BANKING ALSO ON ENOUGH MIXING WITH 5-10 KTS OF WIND. ..05.. && .LONG TERM...(WEDNESDAY THROUGH NEXT MONDAY)... UNSETTLED PERIOD TO CONTINUE WITH SEVERAL CLIPPER TYPE SYSTEMS TO AFFECT THE AREA. FIRST CLIPPER SYSTEM TO AFFECT THE AREA LATE WED NIGHT INTO THURSDAY EVENING...BRINGING THE POTENTIAL FOR A LITTLE SNOW. NEXT CLIPPER SYSTEM TO BE MORE OF A HYBRID WITH IT AFFECTING THE AREA DURING THE WEEKEND WITH THE POTENTIAL FOR A LITTLE SNOW AS WELL. TEMPS TO BE A CHALLENGE WITH POTENTIAL A LARGE GRADIENT ACROSS THE CWFA. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ 05/08 ia AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CARIBOU ME 927 PM EST TUE MAR 8 2005 .SYNOPSIS...AN INTENSIFYING LOW PRESSURE SYSTEM OFF THE SOUTHERN NEW ENGLAND COAST WILL MOVE RAPIDLY NORTH THROUGH THE GULF OF MAINE AND THEN ALONG THE MAINE AND NEW BRUNSWICK BORDER. THIS LOW WILL MOVE NORTH OF THE STATE EARLY WEDNESDAY. A WEAK HIGH PRESSURE RIDGE WILL BUILD ACROSS NEW ENGLAND BY LATE THURSDAY. && .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... UPDATE #2: STILL GETTING REPORTS OF HIGH WIND GUSTS IN ZN30. DECIDED ON UPGRADING WINTER WX ADVS IN ZNS 6 & 32 TO WINTER STORM WARNINGS. THIS WAS BASED ON LATEST RADAR TRENDS...SWOMCD/RUC SOUNDINGS. REPORTS COMING IN FROM THESE AREAS OF SOME ACCUMS OF SLEET & SOME ICING DUE TO FZRA. NO OTHER CHGS ATTM. HAVE BASE TRACK OF LOW PRESSURE ON COMPROMISE BETWEEN GFS/UKMET AND ECMWF. THIS CONSENSUS BRINGS LOW PRESSURE ALONG THE BORDER OF MAINE AND NEW BRUNSWICK. CURRENT OBSERVATIONS CONTINUE TO SHOW A SLOW TREND OF COLD AIR DRAINAGE. EXPECT THIS TO RESULT IN A CHANGE TO SNOW FROM WEST TO EAST GOING INTO THE EVENING. EXPECT ANOTHER PERIOD OF WARM ADVECTION AHEAD OF THE LOW CENTER AS IT MOVES ALONG THE EASTERN PORTION OF THE FORECAST AREA AROUND 06Z. THIS WILL RESULT IN A CHANGE BACK TO A MIXTURE OF SLEET AND FREEZING RAIN FOR SEVERAL HOURS...WHICH WILL REDUCE POTENTIAL SNOW AMOUNTS IN EASTERN PORTIONS OF THE FORECAST AREA. EXPECT PRECIPITATION TO RAPIDLY CHANGE BACK TO SNOW IN ALL AREAS AFTER 06Z. THE GFS LOW LEVEL JET IS NOT AS STRONG ACROSS THE SOUTHEASTERN PORTION OF THE FORECAST AREA AS IT WAS IN PREVIOUS RUNS...SO WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS AREA AND MENTION STRONG WINDS. HAVE UPGRADED WATCHES TO WINTER STORM WARNINGS IN THE WESTERN AREAS. THURSDAY THROUGH FRIDAY...THIS PERIOD SHOULD BE RATHER UNEVENTFUL WEATHER WISE. EXPECT WIDESPREAD FLURRIES ON THU WITH SUBSTANTIAL LOW LEVEL MOISTURE STILL PRESENT OVER THE FORECAST AREA AND WEAK CYCLONIC CURVATURE AT THE SURFACE. 12Z NWP STILL SUGGESTING THAT WEAK SURFACE RIDGING SHOULD ARRIVE OVER THE AREA THU NIGHT AND SLOWLY MOVE EAST ON FRI. EXPECT PARTIAL CLEARING THURSDAY NIGHT WITH CLOUDS INCREASING AGAIN ON FRI. SOME WARM ADVECTION INDUCED LIGHT SNOW POSSIBLE OVER WESTERN SECTIONS BY LATE IN THE DAY ON FRI. USED A BLEND OF MOS TEMPERATURES FOR MAXIMUMS/MINIMUMS. && .LONG TERM ( FRI NIGHT THROUGH TUE )... A WEAKENING AREA OF LOW PRESSURE COULD BRING A CHANCE OF SNOW TO THE REGION FRIDAY NIGHT...WHILE A STRONGER LOW INTENSIFIES ALONG THE MID ATLANTIC COAST. THE EXACT TRACK OF THIS SECONDARY LOW REMAINS UNCERTAIN AT THIS TIME...THOUGH LIKELY TRACKING NORTH ACROSS THE MARITIMES. A FURTHER WEST TRACK OF THIS LOW COULD BRING ANOTHER SIGNIFICANT SNOW EVENT TO THE REGION LATER SATURDAY THROUGH SUNDAY...WHILE A MORE EASTERLY TRACK WOULD RESULT IN LESSER ACCUMULATIONS. FOR NOW WILL COMPROMISE...WITH CHANCE POPS FOR SNOW ACROSS THE REGION SATURDAY/SUNDAY TAPERING TO SNOW SHOWERS LATER SUNDAY. WILL KEEP CHANCE POPS FOR SNOW SHOWERS ACROSS THE NORTH/MOUNTAINS SUNDAY NIGHT WITH THE EXITING SURFACE LOW WHILE SKIES BECOME PARTLY CLOUDY DOWNEAST. WITH THE UPPER LOW IN THE VICINITY...COULD HAVE LINGERING SNOW SHOWERS ACROSS THE NORTH/MOUNTAINS MONDAY WITH PARTLY CLOUDY SKIES DOWNEAST. SURFACE HIGH PRESSURE SHOULD RIDGE TOWARD THE REGION MONDAY NIGHT/TUESDAY. TEMPERATURES WILL REMAIN AT BELOW NORMAL LEVELS THROUGH THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION... IFR CONDITIONS TONIGHT ARE EXPECTED TO IMPROVE TO MVFR CONDITIONS DURING THE DAY WEDNESDAY AS THE LOW PRESSURE CENTER MOVES OFF TO THE NORTHEAST. && .MARINE... HAVE OVERLAYED THE MMG/MOS OVER THE GFS/80 USING THE MATCH GUIDANCE TOOL. THE LOW PRESSURE SYSTEM WILL MOVE DIRECTLY ACROSS THE COASTAL WATERS WHICH WILL CAUSE THE WINDS TO DIMINISH FOR A SHORT PERIOD OF TIME. HAVE INITIALIZED WAVE GRIDS WITH WNA WAVE WATCH III BUT HAVE RAISED SEA HEIGHTS FOR THE FIRST THREE PERIODS SINCE HIGHER WINDS WERE USED IN FORECAST GRIDS THAN IN WAVE MODEL WIND FIELD. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER STORM WARNING FOR MEZ001>004 TO 6 AM WEDNESDAY. ...WINTER STORM WARNING FOR MEZ005-010-011-015-016-029-031 FROM 6 PM TUESDAY TO 6 AM WEDNESDAY. ...WINTER STORM WARNING FOR MEZ006 & 032 UNITL 9 AM EST WEDNESDAY ...WINTER WEATHER ADVISORY FOR MEZ017-030 FROM 6 PM EST TUESDAY TO 6 AM WEDNESDAY. ...HIGH WIND WARNING FOR MEZ017-030 TIL MIDNIGHT EST WEDNESDAY MARINE...GALE WARNING FOR ANZ050 FROM 6 AM WEDNESDAY TO 10 AM WEDNESDAY. ...STORM WARNING FOR ANZ050 FROM 6 PM TUESDAY TO 6 AM WEDNESDAY. && $$ UPDATE...HEWITT/CALDERON SHORT TERM/MARINE...MIGNONE/GABRIC LONG TERM/MARINE...NORCROSS AVIATION...WOLFE me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1002 PM EST TUE MAR 8 2005 .UPDATE... FLURRIES ARE FINALLY PUSHING OFF TO THE EAST AND DIMINISHING ACROSS THE AREA. LINGERING DIURNAL CLOUDS WILL ALSO QUICKLY DIMINISH OVER THE NEXT HOUR OR SO. NORTHWESTERLY FLOW IS KEEPING THE LAKE EFFECT ACTIVITY CONFINED MAINLY TO THE LAKE MICHIGAN SHORELINE. GIVEN THE VERY DRY AIR OVER THE REGION... SKIES SHOULD BE MOSTLY CLEAR OUTSIDE OF THE LAKE EFFECT. BASED ON THE LAKE CLOUDS OVER SOUTHERN LAKE MICHIGAN... LOW LEVEL WINDS LOOK TO BE A LITTLE MORE WESTERLY THAN INDICATED BY THE ETA. THE RUC SEEMS TO BE HANDLING THE LOW LEVEL FLOW A LITTLE BETTER. THIS FLOW MAY STILL ALLOW SOME STRAY LAKE CLOUDS TO WORK THEIR WAY INTO THE SOUTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT. THE GRADIENT SHOULD BE STRONG ENOUGH TONIGHT TO KEEP LOW TEMPS FROM DROPPING OFF TOO MUCH. THE CURRENT MIN TEMP FORECAST LOOKS ON TARGET. && .AVIATION... ISSUED AT 616 PM THE CLOUDS AND SCATTERED FLURRIES WILL QUICKLY DIMINISH OVER THE NEXT HOUR OR TWO WITH THE LOSS OF DIURNAL HEATING. THE CLEARING SKIES WILL ALSO ALLOW FOR SOME DECOUPLING WHICH WILL BRING THE WIND SPEEDS DOWN UNDER 10KTS BY 02Z. SOME WEAK SURFACE TROUGHING IS EXPECTED TO DEVELOP OVERNIGHT IN RESPONSE TO SOME SHORT WAVE TROUGHS PASSING THROUGH THE REGION. THIS WILL ALLOW THE BOUNDARY LAYER FLOW TO BECOME MORE WEST-NORTHWESTERLY LATE TONIGHT AND INTO THE DAY WEDNESDAY. LAKE EFFECT STRATO CU SHOULD REMAIN EAST OF THE TAF SITES OVERNIGHT. WILL LOOK FOR CLOUDS TO INCREASE WED AFTERNOON WITH THE HELP OF SOME DIURNAL HEATING AND MOISTURE FLUX OFF LAKE MICHIGAN. && .SHORT TERM... TONIGHT AND WEDNESDAY A QUIET BUT COLD STRETCH OF WEATHER IS IN STORE FOR THE SHORT TERM. AFTERNOON HIGH TEMPS TODAY ARE WITHIN A FEW DEGREES OF RECORD LOW MAXES FOR MARCH 8TH AND TONIGHT'S LOWS WILL BE IN THE SINGLE DIGITS IN LOCATIONS SHELTERED FROM A LIGHT GRADIENT WIND. HOWEVER, RECORD LOWS LOOK SAFE AS ALL ARE NEAR OR BELOW ZERO FOR THE 8TH AND 9TH. WITH THE LOSS OF DAYTIME HEATING, NEUTRAL NW LOW LEVEL FLOW WILL LEAD TO A CLEARING TREND THIS EVENING, ESPECIALLY AROUND THE TRI CITIES, FLINT, AND THUMB. LOCATIONS AROUND DETROIT AND THE OHIO BORDER WILL BE IN LINE FOR SOME STRATOCU FROM LAKE MICHIGAN AS THE LOW LEVEL FLOW BACKS TO JUST NORTH OF WEST. THE UPPER FLOW WILL BE CONFLUENT TO START THE EVENING BUT AN UPPER TROF WILL SWING THROUGH THE GREAT LAKES, ASSOCIATED WITH THE DEVELOPING WAVE OVER THE PLAINS. THIS WILL ATTEMPT TO REINFORCE THE COLD AIR IN LOWER MICHIGAN TOWARD SUNRISE AND ON WEDNESDAY. THE 12Z MODELS SUPPORT THIS TO VARYING DEGREES. THE GFS AND LOCAL WRF SHOW LESS INFLUENCE FROM LAKE MICHIGAN IN TERMS OF PRESSURE FALLS OVER SW LOWER COMPARED TO THE NAM12 AND EVEN THE NGM. SUSPECT AT LEAST A COMBINATION OF LAKE TROFFINESS AND SURFACE REFLECTION TO BE THE CASE, WHICH WILL LEAD TO A CHANCE OF SNOW SHOWERS WHEN ADDED TO DIURNAL HEATING ON WEDNESDAY. EVEN WITH THE MARCH SUN, PREFER HIGH TEMPERATURE GUIDANCE IN THE LOWER TO MID 20S BASED ON TODAY'S PERFORMANCE. && .LONG TERM... WEDNESDAY NIGHT THROUGH TUESDAY THROUGH SUNDAY...WE REMAIN UNDER NORTHWEST FLOW WITH SEVERAL SHORTWAVES DROPPING DOWN ACROSS THE AREA. THE FIRST OF THESE IS EXPECTED TO CLIP NORTHERN LOWER AND THE THUMB WEDNESDAY NIGHT BUT WILL BE LIMITED BY A DRY ATMOSPHERE ABOVE 850MB. HAVE A CHANCE OF SNOW SHOWERS NORTH OF I-94 AFTER MIDNIGHT ON WEDNESDAY BUT NOT EXPECTING MORE THAN A DUSTING. LAKE EFFECT SNOW SHOWERS SHOULD DO WELL OVER THE EAST CENTRAL PORTION OF LAKE HURON AND OVER ONTARIO AS 850MB TEMPS DROP DOWN TO -18C GENERATING AT LEAST 400 J/KG OF LAKE INDUCED CAPE. THESE SNOW SHOWERS OVER THE LAKE SHOULD END THURSDAY MORNING AS TEMPS WARM LOWERING INVERSION HEIGHTS AND WINDS BACKING AHEAD OF THE NEXT SYSTEM. THE NEXT WAVE MOVING OVER THE AREA THURSDAY EVENING WILL BE A LITTLE STRONGER. MODELS STRUGGLING A BIT ON THE TRACK OF THE SURFACE LOW AHEAD OF THIS WAVE. THE GFS HAS BEEN TRENDING FURTHER SOUTH WITH THE LOW MOVING FROM ILLINOIS ACROSS THE OHIO RIVER VALLEY. WRFXX IS SIMILAR TO GFS WITH THE TRACK OF THE SYSTEM WHILE ECMWF/GEM ARE A LITTLE FURTHER NORTH. NAM IS THE FURTHEST NORTH WITH A TRACK ACROSS CENTRAL LOWER BEFORE BEING ABSORBED BY THE HUDSON BAY LOW ON FRIDAY. PREFER A SURFACE LOW TRACK BLENDING THE ECMWF/WRFXX/GFS WHICH SEEMS TO BE THE GREATEST CONSENSUS. WITH THAT IN MIND THE IMPLICATIONS FOR THE FORECAST ARE THAT WE WILL STAY IN THE COLD SECTOR THE ENTIRE TIME AND MISS THE BEST PRECIP TO THE SOUTH...OVER INDIANA AND OHIO. LIFT ON 275K ISENTROPIC SURFACE SHOWS A LITTLE BIT OF WARMING GIVING OUR SOUTHERN COUPLE TIERS OF COUNTIES A DECENT SHOT AT LIGHT PRECIP THURSDAY AFTERNOON. THEN OVERNIGHT GFS/WRFXX BOTH SHOW AN AREA OF GOOD 850-500MB FRONTOGENESIS ROTATING ACROSS THE MI/IN/OH BORDER OVERNIGHT SO EXPECTING UP TO A COUPLE INCHES OF SNOW ACROSS SOUTHEASTERN MI. AT THIS TIME...MODELS IN FAIRLY GOOD AGREEMENT ABOUT A REINFORCING SHORTWAVE DROPPING DOWN ACROSS LOWER MICHIGAN FRIDAY NIGHT. AS A SURFACE TROUGH LINGERS OVER THE AREA FROM THE PREVIOUS SYSTEM NOW AT THE EAST COAST...HAVE ADDED A CHANCE OF SNOW SHOWERS TO FORECAST. SHORTWAVE TIMING IS STILL SUBJECT TO CHANGE THROUGH THE WEEKEND AS MODELS STRUGGLE WITH THESE SMALLER FEATURES. AS WE HEAD INTO NEXT WEEK...MODELS HINTING AT A BIT OF A PATTERN CHANGE AS A SHORTWAVE DROPS DOWN INTO THE PACIFIC NORTHWEST CAUSING MORE ZONAL FLOW OVER THE EASTERN PART OF THE COUNTRY. IF THIS PANS OUT...LOOK FOR A GRADUAL WARMING IN TEMPS INTO NEXT WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... .MI...NONE. .LAKE HURON...NONE. .LAKE ST CLAIR...NONE. .MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION/UPDATE...SC SHORT TERM...BT LONG TERM...KEK mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 910 PM EST TUE MAR 8 2005 .DISCUSSION... .SHORT TERM... 00Z RAOBS/WV IMAGERY AND RUC ANALYSIS SHOW DEEP TROF OVER ERN NAMERICA BTWN HI AMPLITUDE RDGS OVER THE W AND IN THE WRN ATLANTIC OCEAN. SHRTWV NOTED OVER ONTARIO IN NW FLOW OVER THE GRT LKS...AND SHRTWV DRAGGING AN H85 THERMAL TROF SWD TOWARD LK SUP PER 00Z H85 RAOBS (H85 TEMP -21C AT YPL) AS WELL AS AN AREA OF HIER MID LVL MSTR ON THE CYC SIDE OF SHRTWV. STN CYGQ JUST N OF LK SUP REPORTING A BKN DECK AS LO AS 4500 FT UNDER THE ENHANCED CLD DESPITE SFC DWPTS ARND -15F AND VERY DRY 00Z YPL/INL SDNGS (THESE RAOB SITES ARE W OF THE ENHANCED CLD IN ONTARIO). THE APRCH OF THE SHRTWV/THERMAL TROF/MID MID LVL MSTR HAS CAUSED THE LES BANDS OVER LK SUP TO BECOME MUCH BETTER DVLPD/FATTER ESPECIALLY OVER THE E HALF OF LK SUP DESPITE THE INGEST OF DRY LLVL AIR...WHERE LONGER FETCH IN OBSVD WNW FLOW PER MQT VWP HAS ALLOWED MORE MOISTENING. MQT 88D INDICATES REFLECTIVITIES IN SOME OF THE BANDS HAVE INCRSD OVER 20DBZ AS HI AS 7K FT IN THE PAST COUPLE OF HRS. THESE RADAR/STLT TRENDS...APRNT RISE IN INVRN HGT TO 8K FT MSL PER MQT VWP...AND APRCH OF SHRTWV WARRANTED THE ISSUANCE OF AN LES ADVY FOR ALGER/NRN SCHOOLCRAFT/LUCE COUNTIES THIS EVNG. BACKING LLVL WINDS IN DVLPG NOCTURNAL LAND BREEZE OVER THE INTERIOR WCNTRL FA ALSO SEEMED TO BE A FVRBL DVLPMNT THAT WOULD INCRS LLVL CNVGC OVER THOSE ERN ZNS. ALTHOUGH LES BANDS EXTEND ACRS THE KEWEENAW PENINSULA AND A BIT INTO WRN LK SUP...FETCH LENGTH ACRS THE W HALF OF THE LK WOULD SEEM TO BE TOO SHORT FOR SGNFT MOISTENING AND SGNFT LES OVER THE KEWEENAW. TEMPS OVER THE INTERIOR WCNTRL ZNS HAVE DROPPED AS LO AS 3 ABOVE AT THE MQT NWS (AND TO 1 ABOVE AT LNL AND EGV IN NRN WI)...WITH DWPTS AS LO AS -8F AT 02Z. MAIN FCST CONCERNS TNGT ARE LES TRENDS/AMTS/GOING HEADLINES OVER THE E AND TEMPS ELSEWHERE. 00Z NAM/RUC SHOW SHRTWV/MID LVL MSTR/H85 THERMAL TROF SLIDING SSEWD TNGT...WITH MOISTENING PASSING ACRS THE ERN ZNS AND THEN BY AFT 15Z WED. BOTH MODELS HINT AT FOCUSED H95 CNVGC ACRS ERN ALGER/LUCE/NRN SCHOOLCRAFT ZNS. THESE FCSTS IN LINE WITH PREVIOUS RUNS AND SUG GOING LES ADVY THERE IS ON TRACK. LES CHART WOULD SUG 4-5"/6 HRS FOR EXPECTED CONDITIONS...BUT WL CUT BACK TO ARND 3"/6 HRS TO ACCOUNT FOR LLVL DRY AIR/SOME FCST SHIFT IN LLVL WINDS DURING THE ADVY PD. OTRW...GOING FCST TMINS OVER THE INTERIOR WCNTRL AS LO AS -10F APPEAR TO BE ON TRACK WITH EXPECTATION THAT MID LVL MSTR WL STAY JUST TO THE E AND LLVL LGT LAND BREEZE WL PERSIST. COORDINATED WITH APX. KC .LONG TERM... FOR WEDNESDAY...NO REAL CHANGE IN THE SURFACE OR UPPER PATTERN UNTIL LATER AS THE HIGH PRESSURE AREA MOVES CLOSER TO THE U.P.. THIS IS DUE TO A SHRTWV OVER BRITISH COLUMBIA MOVING TO SASKATCHEWAN (WHICH RESULTS IN RIDGING OUT AHEAD OF IT OVER THE DAKOTAS). ONE CHANGE THOUGH IS A LITTLE MODERATION IN 850MB TEMPS WHICH WILL MOVE INTO UPPER MICHIGAN ON WEDNESDAY (NAM SHOWS THEM RISING TO -14C IN THE WEST BY 21Z BUT STILL -19C IN THE EAST). WITH THE WARMING AT 850MB...SHOULD SEE A SIMILAR WARMING AT THE SURFACE. HOWEVER...ONLY EXPECTING READINGS A FEW DEGREES WARMER. CURRENT TEMPS IN THE LOW TO MID 20S LOOK GOOD. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...CLIPPER TYPE SHRTWV AND ASSOCIATED SURFACE LOW TRACK AND STRENGTH REMAIN PROBLEMATIC ON THIS CYCLE...WITH NOW THE 12Z GFS DROPPING THEM BOTH FURTHER SOUTH. NAM/UKMET/CANADIAN ARE ALL PRETTY SIMILAR WITH THE SURFACE LOW TRACKING ACROSS NORTHERN WI ON THU. MEANWHILE THE GFS TAKES IT THROUGH IOWA. THESE DIFFERENCES START OFF EVEN TONIGHT WITH REGARDS TO WHERE THE CLIPPER DEVELOPS (GFS NEAR YELLOWKNIFE AT 12Z WED COMPARED TO NW SASKATCHEWAN BY THE UKMET/NAM). COORDINATED WITH HPC ON THIS ISSUE AND THE RECOMMENDATION WAS TO FOLLOW A COMPROMISE OF THE 12Z GFS AND THE NAM. ACTUALLY...THE 00Z GFS RUN AND MOST OF THE 06Z GFS ENSEMBLES LOOK LIKE THIS COMPROMISE. SHOULD MENTION THOUGH THAT THE RUC13 IS EVEN FURTHER NORTH THAN THE NAM. AS STATED IN THE PREVIOUS AFD...THE BETTER CHANCES FOR SNOW WILL REMAIN FURTHER SOUTH...BUT WILL MAINTAIN A CHANCE ACROSS THE ENTIRE CWA UNTIL THE MODELS CAN COME INTO BETTER AGREEMENT. TEMPERATURES WEDNESDAY NIGHT AND THURSDAY WILL BE WARMER THAN TONIGHT AND WEDNESDAY WITH THE CLOUD COVER AND WARM ADVECTION THAT OCCURS AHEAD OF CLIPPER. COLD AIR COMING IN BEHIND THE SYSTEM (ONLY -13 TO -15C BY 12Z FRI) WILL RESULT IN THE DEVELOPMENT OF LAKE EFFECT SNOW SHOWERS...PRIMARILY FOR THOSE COUNTIES UNDER NW WINDS. AGAIN...UNTIL THE TRACK AND TIMING OF THE SHRTWV/LOW BECOME CLEARER...WILL KEEP A CHANCE OF SNOW SHOWERS EVERYWHERE. MIN TEMPS THURSDAY NIGHT EXPECTED TO BE A FEW DEGREES COOLER THAN WEDNESDAY NIGHT DUE TO THE COLD ADVECTION. FRIDAY AND FRIDAY NIGHT...ALL OF THE MODELS SHOW ANOTHER SHRTWV DROPPING DOWN INTO MN ON FRI BEHIND THE CLIPPER SYSTEM. THIS WILL HELP TO DRAW SOME CHILLY AIR INTO UPPER MICHIGAN WITH 850MB TEMPS FALLING AT LEAST TO -17C BY 00Z SAT AND AROUND -20C BY 12Z SAT. THERE ARE SOME DIFFERENCES IN REGARDS TO HOW THE ACTUALLY SURFACE REFLECTION OF THE SHRTWV MOVES THROUGH...WITH THE GFS HAVING A NORTHEAST TO SOUTHWEST TROUGH WHEREAS THE NAM IS MORE NORTH TO SOUTH. THESE DIFFERENCES WILL DETERMINE WHERE THE LAKE EFFECT WILL BE...SO FOR NOW WILL CONTINUE A CHANCE OF SNOW SHOWERS. SOME LIGHT SNOW SHOULD ALSO ACCOMPANY THE SHRTWV BUT DO NOT THINK THERE WILL BE MUCH IN THE WAY OF ACCUMULATION DUE TO LITTLE MOISTURE WITH IT. HIGH AND LOW TEMPERATURES WILL ALSO BE COOLING THROUGH THIS TIME FRAME DUE TO THE COLD ADVECTION. EXTENDED (SAT THROUGH TUE)...MODELS REMAIN SIMILAR TO YESTERDAY IN REGARDS TO THE UPPER PATTERN CHANGES...WITH THE RIDGE ALONG THE WEST COAST RETROGRADING TOWARDS ALASKA AND A PERSISTENT BLOCKING HIGH OVER THE NORTH ATLANTIC. THIS KEEPS A GENERAL TROUGH SITUATED THROUGH THE PERIOD OVER EASTERN CANADA AND THE NORTHERN TIER OF THE U.S.. NOT EXPECTING THE TROUGH TO MOVE ANYWHERE IN THE NEAR FUTURE EITHER AS THERE ARE HINTS THAT THE BLOCKING HIGH NEAR GREENLAND MAY TRY TO CONNECT WITH THE RIDGE OVER THE EAST PACIFIC. THE DETAILS IN THE TROUGH FOR THE WEEKEND INTO EARLY NEXT WEEK ARE A LITTLE LESS CERTAIN...NOTED BY THE VARIABILITY BETWEEN THE 08/12Z ECMWF AND 09/00Z ECMWF RUNS. NONETHELESS...THERE IS SOME AGREEMENT FROM BOTH YESTERDAY\S RUNS AND TODAY. A LOW PRESSURE TROUGH ASSOCIATED WITH THE LOW THAT MOVED THROUGH THU NIGHT/FRI WILL REMAIN OVER UPPER MI ON SAT. 850MB TEMPS OF -15 TO -17C OVERSPREADING THE LAKE AND NW WINDS WILL KEEP LAKE EFFECT GOING. ON SUN...A SHRTWV WILL DROP THROUGH WESTERN CANADA RESULTING IN A LOW PRESSURE TROUGH OVER MANITOBA. THIS TROUGH WILL SWING THROUGH UPPER MI SUN NIGHT BRINGING SOME LIGHT SNOW WITH IT. BEHIND THE TROUGH...ARCTIC HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE PLAINS...RESULTING IN MORE LAKE EFFECT SNOWS FOR MON INTO TUE. AJ && .MQT...WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING IN EFFECT FOR LAKE SUPERIOR. LAKE EFFECT SNOW ADVISORY UNTIL 17Z WEDNESDAY MIZ006-007-085. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 325 PM EST TUE MAR 8 2005 .DISCUSSION... MAIN FORECAST CONCERNS ARE SNOW ACCUMULATIONS TONIGHT IN THE EAST AND CLIPPER SYSTEM FOR WED NIGHT THROUGH THU NIGHT. CURRENT WEATHER...19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED THE POSITIVE PNA/NEGATIVE NAO PATTERN CONTINUING ACROSS NORTH AMERICA WITH A RIDGE OVER THE WEST AND A TROUGH IN THE EAST. THIS PUTS UPPER MICHIGAN IN NW FLOW ALOFT. ONE SHRTWV PASSED THROUGH THIS MORNING ACROSS WESTERN LAKE SUPERIOR...BRINGING 850MB TEMPS OF -20C ACROSS UPPER MICHIGAN AS SEEN ON THE 12Z RAOBS. DRY AIR ALSO FOLLOWED THE SHRTWV...WITH 850MB DEWPOINT DEPRESSIONS AROUND 8C AT INL AND CWPL. THIS DRY AIR HAS REALLY RESTRICTED LAKE EFFECT OVER WESTERN LAKE SUPERIOR TO A FEW SCATTERED SNOW SHOWERS. IN FACT...IWD DEWPOINT IS AT -6F AND CMX AT 1F. 19Z TAMDAR SOUNDING FOR CMX ALSO INDICATIVE OF THE DRY AIR...SHOWING DEWPOINT DEPRESSIONS OF 4C OR GREATER FROM SURFACE UP TO 600MB. HOWEVER...WITH THE NW LOW LEVEL FLOW GOING ACROSS A LONGER FETCH OF EASTERN LAKE SUPERIOR...NUMEROUS SNOW SHOWERS PERSIST THERE. THESE HAVE BEEN AFFECTING ALGER... NORTHERN SCHOOLCRAFT AND LUCE COUNTIES. AT THE SURFACE...A LOW PRESSURE TROUGH WAS ORIENTED ALONG THE SOUTHERN LAKE SUPERIOR SHORELINE WHILE HIGH PRESSURE WAS SITUATED OVER GRAND FORKS. THE NEXT SHRTWV OF INTEREST IS LOCATED ALONG THE CENTRAL BRITISH COLUMBIA COAST...WHICH IS PROGGED TO AFFECT UPPER MICHIGAN THU INTO FRI. TONIGHT AND WEDNESDAY...NO REAL CHANGE IN THE SURFACE OR UPPER PATTERN UNTIL LATER ON WEDNESDAY AS THE HIGH PRESSURE AREA MOVES CLOSER TO THE U.P.. THIS IS DUE TO THE SHRTWV OVER BRITISH COLUMBIA MOVING TO SASKATCHEWAN (WHICH RESULTS IN RIDGING OUT AHEAD OF IT OVER THE DAKOTAS). ONE CHANGE THOUGH IS A LITTLE MODERATION IN 850MB TEMPS WHICH WILL MOVE INTO UPPER MICHIGAN ON WEDNESDAY (NAM SHOWS THEM RISING TO -14C IN THE WEST BY 21Z BUT STILL -19C IN THE EAST). WITH CONTINUED NORTHWESTERLY WINDS ONLY BACKING SOMEWHAT LATER ON WEDNESDAY...WHERE THE BANDS ARE RIGHT NOW WILL BE IN THE GENERAL SAME PLACE THROUGH THE NEXT 24 HOURS. THE HEAVIEST SNOWFALL SHOULD REMAIN OVER LUCE COUNTY WHERE THE BEST CONVERGENCE TAKES PLACE. ACTUALLY...A LITTLE EXTRA MOISTURE WILL COME IN ACROSS THE EAST HALF OF THE LAKE TONIGHT (NOTE CLOUDS MOVING SOUTHWARD IN NORTHERN ONTARIO AT THE MOMENT)...WHICH MAY HELP TO BOOST ACCUMULATIONS. WILL GO UP TO 4 INCHES IN NORTHERN LUCE COUNTY. AS FOR WESTERN LAKE SUPERIOR...BANDS MAY REFORM BETTER TONIGHT WITH DIURNAL COOLING...BUT NOT EXPECTING ANYTHING GREATER THAN SCATTERED GIVEN THE PRESENCE OF DRY AIR. STILL LOOKS LIKE A CHILLY NIGHT IN THE INTERIOR SECTIONS WHERE SURFACE WINDS DECOUPLE AND SKIES CLEAR OUT. COOP GUIDANCE SHOWS TEMPS AROUND -10F AT CHAMPION WHICH IS DEFINITELY NOT OUT OF THE QUESTION. FOR WEDNESDAY...WITH THE WARMING AT 850MB...SHOULD SEE A SIMILAR WARMING AT THE SURFACE. HOWEVER...ONLY EXPECTING READINGS A FEW DEGREES WARMER. CURRENT TEMPS IN THE LOW TO MID 20S LOOK GOOD. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...CLIPPER TYPE SHRTWV AND ASSOCIATED SURFACE LOW TRACK AND STRENGTH REMAIN PROBLEMATIC ON THIS CYCLE...WITH NOW THE 12Z GFS DROPPING THEM BOTH FURTHER SOUTH. NAM/UKMET/CANADIAN ARE ALL PRETTY SIMILAR WITH THE SURFACE LOW TRACKING ACROSS NORTHERN WI ON THU. MEANWHILE THE GFS TAKES IT THROUGH IOWA. THESE DIFFERENCES START OFF EVEN TONIGHT WITH REGARDS TO WHERE THE CLIPPER DEVELOPS (GFS NEAR YELLOWKNIFE AT 12Z WED COMPARED TO NW SASKATCHEWAN BY THE UKMET/NAM). COORDINATED WITH HPC ON THIS ISSUE AND THE RECOMMENDATION WAS TO FOLLOW A COMPROMISE OF THE 12Z GFS AND THE NAM. ACTUALLY...THE 00Z GFS RUN AND MOST OF THE 06Z GFS ENSEMBLES LOOK LIKE THIS COMPROMISE. SHOULD MENTION THOUGH THAT THE RUC13 IS EVEN FURTHER NORTH THAN THE NAM. AS STATED IN THE PREVIOUS AFD...THE BETTER CHANCES FOR SNOW WILL REMAIN FURTHER SOUTH...BUT WILL MAINTAIN A CHANCE ACROSS THE ENTIRE CWA UNTIL THE MODELS CAN COME INTO BETTER AGREEMENT. TEMPERATURES WEDNESDAY NIGHT AND THURSDAY WILL BE WARMER THAN TONIGHT AND WEDNESDAY WITH THE CLOUD COVER AND WARM ADVECTION THAT OCCURS AHEAD OF CLIPPER. COLD AIR COMING IN BEHIND THE SYSTEM (ONLY -13 TO -15C BY 12Z FRI) WILL RESULT IN THE DEVELOPMENT OF LAKE EFFECT SNOW SHOWERS...PRIMARILY FOR THOSE COUNTIES UNDER NW WINDS. AGAIN...UNTIL THE TRACK AND TIMING OF THE SHRTWV/LOW BECOME CLEARER...WILL KEEP A CHANCE OF SNOW SHOWERS EVERYWHERE. MIN TEMPS THURSDAY NIGHT EXPECTED TO BE A FEW DEGREES COOLER THAN WEDNESDAY NIGHT DUE TO THE COLD ADVECTION. FRIDAY AND FRIDAY NIGHT...ALL OF THE MODELS SHOW ANOTHER SHRTWV DROPPING DOWN INTO MN ON FRI BEHIND THE CLIPPER SYSTEM. THIS WILL HELP TO DRAW SOME CHILLY AIR INTO UPPER MICHIGAN WITH 850MB TEMPS FALLING AT LEAST TO -17C BY 00Z SAT AND AROUND -20C BY 12Z SAT. THERE ARE SOME DIFFERENCES IN REGARDS TO HOW THE ACTUALLY SURFACE REFLECTION OF THE SHRTWV MOVES THROUGH...WITH THE GFS HAVING A NORTHEAST TO SOUTHWEST TROUGH WHEREAS THE NAM IS MORE NORTH TO SOUTH. THESE DIFFERENCES WILL DETERMINE WHERE THE LAKE EFFECT WILL BE...SO FOR NOW WILL CONTINUE A CHANCE OF SNOW SHOWERS. SOME LIGHT SNOW SHOULD ALSO ACCOMPANY THE SHRTWV BUT DO NOT THINK THERE WILL BE MUCH IN THE WAY OF ACCUMULATION DUE TO LITTLE MOISTURE WITH IT. HIGH AND LOW TEMPERATURES WILL ALSO BE COOLING THROUGH THIS TIME FRAME DUE TO THE COLD ADVECTION. EXTENDED (SAT THROUGH TUE)...MODELS REMAIN SIMILAR TO YESTERDAY IN REGARDS TO THE UPPER PATTERN CHANGES...WITH THE RIDGE ALONG THE WEST COAST RETROGRADING TOWARDS ALASKA AND A PERSISTENT BLOCKING HIGH OVER THE NORTH ATLANTIC. THIS KEEPS A GENERAL TROUGH SITUATED THROUGH THE PERIOD OVER EASTERN CANADA AND THE NORTHERN TIER OF THE U.S.. NOT EXPECTING THE TROUGH TO MOVE ANYWHERE IN THE NEAR FUTURE EITHER AS THERE ARE HINTS THAT THE BLOCKING HIGH NEAR GREENLAND MAY TRY TO CONNECT WITH THE RIDGE OVER THE EAST PACIFIC. THE DETAILS IN THE TROUGH FOR THE WEEKEND INTO EARLY NEXT WEEK ARE A LITTLE LESS CERTAIN...NOTED BY THE VARIABILITY BETWEEN THE 08/12Z ECMWF AND 09/00Z ECMWF RUNS. NONETHELESS...THERE IS SOME AGREEMENT FROM BOTH YESTERDAY\S RUNS AND TODAY. A LOW PRESSURE TROUGH ASSOCIATED WITH THE LOW THAT MOVED THROUGH THU NIGHT/FRI WILL REMAIN OVER UPPER MI ON SAT. 850MB TEMPS OF -15 TO -17C OVERSPREADING THE LAKE AND NW WINDS WILL KEEP LAKE EFFECT GOING. ON SUN...A SHRTWV WILL DROP THROUGH WESTERN CANADA RESULTING IN A LOW PRESSURE TROUGH OVER MANITOBA. THIS TROUGH WILL SWING THROUGH UPPER MI SUN NIGHT BRINGING SOME LIGHT SNOW WITH IT. BEHIND THE TROUGH...ARCTIC HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE PLAINS...RESULTING IN MORE LAKE EFFECT SNOWS FOR MON INTO TUE. && .MQT...WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING IN EFFECT FOR LAKE SUPERIOR. && $$ AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1020 AM EST TUE MAR 8 2005 .DISCUSSION... VISIBLE IMAGERY THIS MORNING SHOWS CONTINUED LES BANDING OVER EASTERN LAKE SUPERIOR...WITH DEVELOPMENT OCCURRING CLOSER TO THE UPSTREAM SHORELINE THAN WOULD BE EXPECTED WITH UPSTREAM DEWPOINT DEPRESSIONS OF 10-15F. HOWEVER...THE COMBINATION OF SOME BOUNDARY LAYER SHEAR AND DIURNAL MIXING IS MAKING THE BANDS MORE CELLULAR IN NATURE WHICH WILL CONTINUE TO LIMIT THEIR ABILITY TO DROP MUCH IN THE WAY OF SNOWFALL IN ANY GIVEN LOCATION THROUGH THE DAY. THE GOING FORECAST LOOKS ON TRACK...WITH NUMEROUS SNOW SHOWERS AND MINOR ACCUMULATIONS OVER THE EAST AND SCATTERED SNOW SHOWERS OUT WEST. INVERSION HEIGHTS GOT A BRIEF BOOST THIS MORNING DUE TO A SHORTWAVE MOVING THROUGH...WHICH CAN BE SEEN ON WATER VAPOR IMAGERY AND RUC ANALYSES. A 1235Z TAMDAR SOUNDING FROM KCMX SHOWED INVERSION HEIGHTS NEAR 800MB...BUT ALSO SHOWED A VERY DRY PROFILE BENEATH THE INVERSION...WHICH IN COMBINATION WITH SHORTER FETCH...IS LIMITING LES OUT WEST. THE BOUNDARY LAYER FLOW OUT WEST IS ALSO MORE ANTICYCLONIC THAN OVER THE EASTERN LAKE. THIS TAMDAR SOUNDING MATCHES THE NAM FORECAST SOUNDING FAIRLY WELL...ALTHOUGH THE NAM LOOKS A BIT TOO MOIST AND PREFER THE FORECAST SOUNDING FROM THE LOCAL LAPS/WRF-ARW. IN GENERAL...WILL FOLLOW THE NAM AND LAPS/WRF-ARW FOR THE EVOLUTION OF LES THROUGH TONIGHT. WINDS WILL BACK TO THE WEST SOME THIS AFTERNOON AS RIDGING TRIES TO WORK INTO THE AREA...THIS WILL FURTHER LIMIT CHANCES FOR ORGANIZED LES ACTIVITY. HOWEVER...ANOTHER SHORTWAVE WILL SLIP THROUGH THE AREA THIS EVENING...AND ALTHOUGH IT IS SHEARED AND PROVIDING LIMITED DIFFERENTIAL VORTICITY ADVECTION...SOME QG FORCING IS PRESENT AND INVERSION HEIGHTS ARE PROGGED TO RISE SLIGHTLY TONIGHT. WINDS ARE PROGGED TO VEER MORE NORTHWESTERLY IN ITS WAKE...KEEPING THE LES OVER PORTIONS OF UPPER MICHIGAN FOR A BIT LONGER UNTIL THE INVERSION CRASHES AND WINDS BACK MORE SUBSTANTIALLY DURING THE DAY ON WEDNESDAY. ADJUSTMENTS TO THE GOING FORECAST WILL BE MINOR...SINCE LATEST ASSESSMENTS AND MODEL GUIDANCE SUPPORT THE CURRENT FORECAST THROUGH TONIGHT. TRH && .PREV DISCUSSION (LATER PERIODS)... MAIN FCST CONCERNS ARE LES TRENDS TODAY INTO WED AND -SN POTENTIAL WITH THU CLIPPER. TONIGHT INTO WED...MAINLY NW FLOW LES WILL CONTINUE. PREFERRED THE WORKSTATION ETA DEPICTION OF MORE PRONOUNCED E CNTRL LK SUPERIOR TROF AND SHIFT OF LOW LVL CONV TOWARD KP53 LATE TONIGHT INTO EARLY WED. FACTORS MENTIONED EARLIER WILL CONTINUE TO KEEP LES IN CHECK WITH ADDITIONAL AMOUNTS AGAIN IN THE 1-3 INCH RANGE. ALTHOUGH SOME CLEARING INLAND WOULD BRING DECENT RADIATIONAL COOLING...GRADIENT REMAINS STRONG ENOUGH TO KEEP WINDS FROM COMPLETELY DECOUPLING. SO...MIN TEMPS MAY ONLY FALL MODESTLY BLO GUIDANCE IN FAVORED COLD SPOTS. BACKING WINDS WITH MORE ACYC FLOW AS THE SFC AND MID LVL RDG EDGE INTO THE WRN LAKES WILL BRING FURTHER DECREASE IN LES WED. WEAK WAA SHOULD ALSO BRING TEMPS BACK INTO THE LOWER TO MID 20S. WED NIGHT INTO THU...MDLS DISPLAY DIFFERENCES WITH TIMING/POSITION OF CLIPPER MOVING INTO THE GRT LAKES REGION. A BLEND OF THE UKMET/CANADIAN SEEMED TO BE A REASONABLE COMPROMISE BTWN THE NAM TO THE NORTH AND THE GFS WITH THE SHRTWV ENERGY AND SFC LOW FARTHEST SOUTH. THIS WOULD STILL KEEP BETTER -SN CHANCES OVER THE SOUTH HLF OR UPR MI. WITH RELATIVELY MODEST DYNAMICS OR MOISTURE INFLOW...LIGHT SNOW WITH 1-2 INCH ACCUMULATIONS AT MOST WOULD BE EXPECTED. JLB && .MQT...WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING IN EFFECT FOR LAKE SUPERIOR. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 919 AM EST TUE MAR 8 2005 .SHORT TERM (TODAY)...UPDATED TEXT PRODUCTS FOR WATCH BOX NUMBER 48 UNTIL 18Z. LATEST RUC-40 SHOWING UPR TROF BECOMING MORE NEGATIVELY TILTED THRU EARLY AFTERNOON. WINDS FIELDS ARE IMPRESSIVE AND EXPECT SOME POTENTIAL DAMAGING WIND GUSTS ALONG THIN LINE OF CONVECTION AS IT ADVANCES EAST THRU EARLY AFTERNOON. WITH STRONG GRADIENT WINDS AWAY FROM CONVECTION...CONTINUE WIND ADVISORY FOR THE AFTERNOON. && .AVIATION...STRONG GUSTY WINDS WITH THE POTENTIAL FOR SOME LOW- LEVEL WIND SHEAR THIS AFTERNOON. MVFR WITH OCCASIONAL IFR WITH BRIEF HEAVY RAIN AND THUNDER THRU MID-AFTERNOON. && .MARINE...VAD WIND PROFILES AND SOUNDING DATA SHOWING WINDS NEAR 70 KT AT 2000 FT. SOME OF THIS WIND LIKELY TO MIX DOWN IN CONVECTION. GRADIENT WINDS ALREADY QUITE STRONG WITH 985 MB LOW OVER SRN VA. CONTINUE ALL GALE WARNINGS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...WIND ADVISORY FOR NCZ047-081-095-098-103-104. MARINE...GALE WARNING FOR AMZ130-135-150-152-154-156-158. && $$ SHORT TERM...COLLINS LONG TERM...COLLINS AVIATION...PRINGLE MARINE...PRINGLE nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 830 PM CST TUE MAR 8 2005 FORECAST CHALLENGE CONCERNS CLOUD TRENDS/TEMPERATURES. SURFACE HIGH PRESSURE TO REMAIN OVER FORECAST AREA OVERNIGHT. REGION WILL ESCAPE MAIN AFFECTS OF SHORT WAVE OVER CENTRAL DAKOTAS AS IT CONTINUES TO DROP SOUTHWARD. CLOUD TRENDS AND RESULTING TEMPERATURES MAIN CONCERN. MID LEVEL CLOUD DECK OVER NORTHERN FA HOLDING TOGETHER AND DROPPING SLOWLY SOUTH KEEPING TEMPERATURES UP. RUC HINTING AT HIGHER RH IN 850-700MB LAYER AND WITH ZONE OF WARM ADVECTION DROPPING SOUTH OVERNIGHT CLOUDS MAY CONTINUE TO DRIFT SOUTH.WILL MONITOR BUT WILL LIKELY RAISE MIN TEMPERATURES SLIGHTLY OVER ALL BUT FAR EAST WHICH WILL MISS MOST OF CLOUD COVER AND CURRENTLY THE COLDEST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 236 PM CST TUE MAR 8 2005 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT. REGIONAL RADAR SHOWING DECENT AREA OF SNOW ALONG AND JUST WEST OF MISSOURI RIVER MOVING INTO WESTERN FORECAST AREA. RUC HAS A REASONABLE ON CURRENT PRECIP AREA...AS DO GFS AND NAM. WILL GO WITH PRETTY HIGH POPS WITH THIS...BUT IT SHOULD DECREASE IN COVERAGE AND INTENSITY THROUGH THE NIGHT WITH SURFACE LOW RETREATING AND HIGH PRESSURE INDUCED DRY WESTERLY FLOW INCREASING. NOT EXPECTING SIGNIFICANT ACCUMULATIONS...INCH OR LESS...AS DURATION IS SHORT. WEDNESDAY NOT LOOKING TOO BAD UNDER INFLUENCE OF HIGH PRESSURE AND WARMING ADVECTION INCREASING IN RESPONSE TO NEXT SYSTEM DROPPING IN FROM NORTHWEST BY EARLY THURSDAY. WITH PLENTY OF WARM AIR IN PLACE...WENT WITH RAIN TO MIX TO ALL SNOW FROM WEST TO EAST ACROSS AREA. WITH THIS SYSTEM...GFS IS WELL REMOVED FROM NAM AND CANADIAN SOLUTION...BUT IS FAVORED BY HPC. THUS...PREVIOUS WEATHER TIMING AND COVERAGE WAS USED AS MAIN INPUT TO THIS PERIOD. PRECIP CERTAINLY LOOKS TO START AS A WARM ADVECTION EVENT...BUT POST SURFACE LOW SOME MID LEVEL FORCING SHOULD KEEP PRECIP IN THE AREA THROUGH LATE THURSDAY. INTERMOUNTAIN HIGH ALONG WITH MODERATE SURFACE LOW SETS SOUTH DAKOTA UP FOR GOOD NORTHWESTERLY WINDS THURSDAY...WHERE IT STILL APPEARS A WIND ADVISORY WILL BE NEEDED. NOT ENOUGH FOR A HIGH WIND WATCH AT THIS TIME...BUT ADVISORY CRITERIA LOOKS LIKE A SAFE BET. .LONG TERM...SATURDAY THROUGH TUESDAY BIGGEST CHALLENGE STILL REMAINS PCPN THROUGH THE EXTENDED. EARLY IN THE EXTENDED NORTH FLOW STILL DOMINATES WITH WELL ESTABLISHED HUDSONS BAY LOW. MODELS STILL INDICATE THE PRESENCE OF A BAROCLINIC ZONE ACROSS THE REGION...WITH MUCH WARMER TEMPS WEST AND COOLER TEMPS EAST. MINOR WAVES STILL PUSH SOUTH AROUND BACKSIDE OF UPPER LOW...PROVIDING REINFORCING SHOTS OF COOLER AIR AT 85H. FOR THE MOST PART...THESE N/NW FLOW SYSTEMS HAVE HAD A TOUGH TIME GETTING HOLD OF ENOUGH MOISTURE TO REALLY PRODUCE MUCH. LITTLE LEARY OF PCPN FCST FOR SATURDAY...AS HIGH IS PUSHING IN FROM NW AND SFC BOUNDARY EAST OF CWA. 85H TEMPS WOULD ALSO LEAN MORE TOWARD SNOW...BUT LEFT PCPN FCST AS IS FOR CONTINUITY SAKE. SUBSIDENCE BEHIND EXITING WAVE AND SFC HIGH PRESSURE SHOULD ENSURE THAT SATURDAY NIGHT IS DRY. CUT BACK POPS ON SUNDAY TO FAR NERN CORNER AS NEXT CLIPPER SYSTEM MOVES THROUGH MN. MONDAY AFTERNOON STRONGER LOW DROPS SOUTH WITH RETROGRADING UPPER LOW. DGEX IS THE MOST IMPRESSED WITH THIS SYSTEM AND PCPN FORECAST...WHILE THE EC TRANSITIONS MORE OF THE ENERGY INTO A DEVELOPING WEST COAST TROF WITH 5H RIDGING OVER CWA. WOULD HAVE REALLY PREFERRED TO PULL OUT SLGT CHC POPS...BUT DEFERRED TO PERSISTENCE TO KEEP FROM FLIP-FLOPPING IN THE EXTENDED. SAME FOR TEMPS. GFS IS MUCH COOLER THAN WHAT THE EC WOULD INDICATE. OF INTEREST IS THE PATTERN SHIFT THAT MODELS ARE FINALLY ADVERTISING. STRONG HUDSONS LOW BEGINS TO RETROGRADE TO THE WEST...ALTHO THERE ARE DIFFERING THOUGHTS TO THIS. ONE THING IS CLEAR IS THAT ALL THE MODELS DO AGREE ON A PATTERN SHIFT APPROACHING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ KNUTSVIG/MOHR sd AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 920 PM CST TUE MAR 8 2005 .DISCUSSION...WILL KEEP PREVIOUS FORECAST UPDATE INTACT THROUGH THE REST OF THE EVENING HOURS. BAND OF LIGHT PRECIPITATION CONTINUES OVER THE SOUTHERN COASTAL BEND SOUTH TO DEEP SOUTH TEXAS AND INTO THE COASTAL WATERS OF THE NORTHWEST GULF OF MEXICO IN ADVANCE OF THE SHORT WAVE TROUGH OVER COAHUILA. THIS SHORT WAVE TROUGH IS SLOWLY MOVING NORTHEAST AND 00Z RUC SHOWS GOOD UPPER LEVEL DIVERGENCE CONTINUING OVER THE FORECAST AREA. THIS REGION OF LIFT WILL MOVE EAST OVERNIGHT AS THE SHORT WAVE TROUGH ENTERS SOUTH TEXAS. ISENTROPIC LIFT WEAKENS OVERNIGHT BUT AM HESITANT TO REMOVE POPS...WILL LOWER POPS TO 20 PERCENT NORTH TO 40 PERCENT ALONG THE SOUTHERN COASTAL BEND AFTER MIDNIGHT. MID LEVEL COOLING ASSOCIATED WITH SHORT WAVE TROUGH WILL STEEPEN THE LAPSE RATES IN THE 70H-50H LAYER SUCH THAT ISOLATED ELEVATED CONVECTION WILL BE POSSIBLE OVERNIGHT. WINDS AND SEAS HAVE DECREASED OFFSHORE...WILL WORD SCEC FOR THE OFFSHORE WATERS TONIGHT. PREVIOUS DISCUSSION ISSUED AT 607 PM... SATELLITE IMAGERY SHOWS MID/UPPER LEVEL SHORT WAVE TROUGH OVER COAHUILA TO THE NORTHERN RIO GRANDE PLAINS EARLY THIS EVENING. WITH DIFFERENTIAL POSITIVE VORTICITY ADVECTION AND MODEST WARM AIR ADVECTION/ISENTROPIC LIFT OCCURRING IN THE LAYER FROM 850-500 MBS...AREAS OF PRECIPITATION CONTINUE TO INCREASE FROM NEAR FALCON RESERVOIR NORTHEAST INTO THE SOUTHERN COASTAL BEND. THE PRECIPITATION HAS FALLEN INTO DRY LAYER AT THE SURFACE...BUT RAIN STARTING TO REACH THE GROUND OVER MOST OF THE SOUTHERN COASTAL BEND. WILL UPDATE THE FORECAST TO RAISE POPS FOR TONIGHT. ISOLATED THUNDERSTORMS ARE STILL A POSSIBILITY ALSO. && .AVIATION...PATCHY/AREAS OF LGT/MOD RA WILL CONT THRU 06Z ACROSS S TX. COULD BE ISOL/EMBEDDED SHRA OR TSRA. OUTSIDE OF PRECIP GENERALLY EXPECT VFR CONDS OVERNIGHT AND INTO TOMORROW MORNING. OVC MID LAYER CLOUD DECK (8K-12K FT) WILL ALSO PERSIST. LGT SE WINDS WILL CONT OVERNIGHT. COLD FRONT WILL MOVE THROUGH S TX MID MORNING ON WED WITH A MOD N WIND DEVELOPING IN THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 053 072 048 077 053 / 60 20 00 00 00 VICTORIA 050 068 043 072 052 / 20 30 00 00 00 LAREDO 055 074 050 080 055 / 40 10 00 00 00 ALICE 052 073 045 079 052 / 30 20 00 00 00 ROCKPORT 054 070 049 072 055 / 40 20 00 00 00 COTULLA 052 071 042 078 048 / 20 10 00 00 00 && .CRP WATCHES/WARNINGS/ADVISORIES...NONE. $$ TMT...SHORT-TERM JR...AVIATION tx AREA FORECAST DISCUSSION...UPDATED FOR AVIATION NATIONAL WEATHER SERVICE FORT WORTH TX 1200 AM CST TUE MAR 8 2005 .AVIATION... NO AVIATION WEATHER CONCERNS THIS AFTERNOON OR EARLY THIS EVENING. EXPECT EAST WINDS TO TURN TO SOUTH/SOUTHEAST WITH TIME AS HIGH PRESSURE BUILDS INTO THE MISSISSIPPI VALLEY REGION AND A SURFACE TROUGH DEVELOPS FROM THE HIGH PLAINS INTO SOUTHWEST TEXAS. MID LEVEL MOISTURE WILL BE ON THE INCREASE TONIGHT AS A SHORT WAVE...CURRENTLY OVER COLORADO...MOVES SOUTHEAST TOWARD NORTH TEXAS. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP OVERNIGHT DUE TO INCREASING LARGE SCALE LIFT STEEP MID LEVEL LAPSE RATES. SCATTERED THUNDERSTORMS SHOULD END ACROSS THE METROPLEX TAF SITES BEFORE 12Z...ONCE DOWNWARD VERTICAL MOTION BEGINS BEHIND THE EXITING SHORT WAVE. SKIES SHOULD CLEAR WEDNESDAY MORNING AND NORTHWEST WINDS WILL INCREASE BEHIND A PASSING COLD FRONT. && .PUBLIC... UPDATING FORECAST TO CHANGE SURFACE WINDS FOR TODAY. 59 && .AVIATION... VFR NEXT 24 HOURS AS HIGH PRESSURE AT THE SURFACE MOVES EAST AND H5 SHORTWAVE ENERGY MOVES TOWARD N TEXAS FROM THE NW. COULD BE SOME TSRA AROUND TONIGHT...BUT MOISTURE APPEARS A BIT LIMITED. THUS...WILL NOT INCLUDE TSRA AT AIRPORTS. NW FLOW TO BECOME SW OVERNIGHT. && .SHORT TERM... BRIEF REPRIEVE TODAY AS FIRST COLD FRONT SURGES INTO THE GULF OF MEXICO...WITH SFC HIGH ANCHORING OVER THE SRN PLAINS. A COOL START TO THE DAY...BEFORE SFC HIGH SHIFTS EWD INTO LWR MS VALLEY THIS AFTN WITH BRIEF RETURN FLOW...AS ROCKIES LEE SIDE TROUGH DEEPENS IN RESPONSE TO IMPRESSIVE S/W IN NW FLOW ALOFT OVER NRN ROCKIES/PLAINS ATTM MOVES SWD WITH ANOTHER COLD FRONT ASSOCIATED WITH IT. COLD 500 MB TEMPS =< -20 DEG C NOTED PER LATEST RUC WITH THIS S/W. THIS SYSTEM TO ARRIVE ACROSS THE RED RIVER BY 03Z TONIGHT/AFTER AS 850-700MB LAYER MOISTURE INCREASES. LAPSE RATES TO BE IN/NEAR 7 DEG C/KM. WILL SLOW PREVIOUS FCST...WITH MOST ACTIVITY OCCURRING BETWEEN 06Z-18Z WED. ETA THE ODD MODEL OUT AND WILL FOLLOW GFS/UKMET /CANADIAN CONSENSUS ON HIGHER POPS...BEST NE. PREVIOUS FCST ALREADY HAS MARGINAL SEVERE HAIL THREAT HANDLED AND WILL HOLD THAT THOUGHT THIS FCST...AS 30-40 KT MID LVL FLOW AND AFOREMENTIONED MID LVL LAPSE RATES WELL SUFFICIENT ENOUGH FOR LOW-END SEVERE HAIL THREAT AND MORNING HWO WILL COVER THIS POTENTIAL. SYSTEM TO BE A QUICK-HITTER WITH FRONT CLEARING AREA WED AFTN WITH DRY/BREEZY/COOLER CONDS GOING INTO WED NIGHT. LEANED WITH COOLER MAV NUMBERS. && .LONG TERM... MORE AMPLIFIED 4-WAVE PATTERN REPLACES PREVIOUS...STAGNANT SPLIT FLOW PATTERN SEEN THE PAST FEW WEEKS HEADING INTO NEXT WEEKEND. SHOULD SEE WARM UP AGAIN THURS...BEFORE ANOTHER COLD FRONT ARRIVES THURS NIGHT/FRI MORNING. NW FLOW WILL CONTINUE HEADING INTO THE WEEKEND WITH ISOLATED/ELEVATED STORMS POSSIBLE AGAIN ACROSS NE 1/2 OF THE REGION AS S/W DRIVES IN FROM THE N ON FRI NIGHT. LOW CONFIDENCE HERE JUST LIKE TODAY WITH THE WILD CARD BEING MOISTURE AVAILABILITY. NICE WARM UP THIS WEEKEND IN RETURN FLOW... BEFORE COOL DOWN OCCURS EARLY NEXT WEEK WITH LOW POPS NORTH. AGAIN...STRESS VERY CONFIDENCE THIS COMING WEEKEND AND NEXT WEEK PD. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 64 45 62 38 / 0 50 20 0 WACO, TX 67 47 66 37 / 0 30 20 0 PARIS, TX 61 42 58 35 / 0 60 20 0 DENTON, TX 64 44 61 37 / 0 60 10 0 MCKINNEY, TX 63 44 60 36 / 0 60 20 0 DALLAS, TX 64 46 62 39 / 0 50 20 0 TERRELL, TX 64 45 61 37 / 0 50 30 0 CORSICANA, TX 65 46 64 37 / 0 30 30 0 TEMPLE, TX 68 48 66 39 / 0 20 30 0 && .FWD WATCHES/WARNINGS/ADVISORIES... TX...NONE. && $$ /05 tx AREA FORECAST DISCUSSION...UPDATED FOR PUBLIC NATIONAL WEATHER SERVICE FORT WORTH TX 1020 AM CST TUE MAR 8 2005 .PUBLIC... UPDATING FORECAST TO CHANGE SURFACE WINDS FOR TODAY. 59 && .AVIATION... VFR NEXT 24 HOURS AS HIGH PRESSURE AT THE SURFACE MOVES EAST AND H5 SHORTWAVE ENERGY MOVES TOWARD N TEXAS FROM THE NW. COULD BE SOME TSRA AROUND TONIGHT...BUT MOISTURE APPEARS A BIT LIMITED. THUS...WILL NOT INCLUDE TSRA AT AIRPORTS. NW FLOW TO BECOME SW OVERNIGHT. && .SHORT TERM... BRIEF REPRIEVE TODAY AS FIRST COLD FRONT SURGES INTO THE GULF OF MEXICO...WITH SFC HIGH ANCHORING OVER THE SRN PLAINS. A COOL START TO THE DAY...BEFORE SFC HIGH SHIFTS EWD INTO LWR MS VALLEY THIS AFTN WITH BRIEF RETURN FLOW...AS ROCKIES LEE SIDE TROUGH DEEPENS IN RESPONSE TO IMPRESSIVE S/W IN NW FLOW ALOFT OVER NRN ROCKIES/PLAINS ATTM MOVES SWD WITH ANOTHER COLD FRONT ASSOCIATED WITH IT. COLD 500 MB TEMPS =< -20 DEG C NOTED PER LATEST RUC WITH THIS S/W. THIS SYSTEM TO ARRIVE ACROSS THE RED RIVER BY 03Z TONIGHT/AFTER AS 850-700MB LAYER MOISTURE INCREASES. LAPSE RATES TO BE IN/NEAR 7 DEG C/KM. WILL SLOW PREVIOUS FCST...WITH MOST ACTIVITY OCCURRING BETWEEN 06Z-18Z WED. ETA THE ODD MODEL OUT AND WILL FOLLOW GFS/UKMET /CANADIAN CONSENSUS ON HIGHER POPS...BEST NE. PREVIOUS FCST ALREADY HAS MARGINAL SEVERE HAIL THREAT HANDLED AND WILL HOLD THAT THOUGHT THIS FCST...AS 30-40 KT MID LVL FLOW AND AFOREMENTIONED MID LVL LAPSE RATES WELL SUFFICIENT ENOUGH FOR LOW-END SEVERE HAIL THREAT AND MORNING HWO WILL COVER THIS POTENTIAL. SYSTEM TO BE A QUICK-HITTER WITH FRONT CLEARING AREA WED AFTN WITH DRY/BREEZY/COOLER CONDS GOING INTO WED NIGHT. LEANED WITH COOLER MAV NUMBERS. && .LONG TERM... MORE AMPLIFIED 4-WAVE PATTERN REPLACES PREVIOUS...STAGNANT SPLIT FLOW PATTERN SEEN THE PAST FEW WEEKS HEADING INTO NEXT WEEKEND. SHOULD SEE WARM UP AGAIN THURS...BEFORE ANOTHER COLD FRONT ARRIVES THURS NIGHT/FRI MORNING. NW FLOW WILL CONTINUE HEADING INTO THE WEEKEND WITH ISOLATED/ELEVATED STORMS POSSIBLE AGAIN ACROSS NE 1/2 OF THE REGION AS S/W DRIVES IN FROM THE N ON FRI NIGHT. LOW CONFIDENCE HERE JUST LIKE TODAY WITH THE WILD CARD BEING MOISTURE AVAILABILITY. NICE WARM UP THIS WEEKEND IN RETURN FLOW... BEFORE COOL DOWN OCCURS EARLY NEXT WEEK WITH LOW POPS NORTH. AGAIN...STRESS VERY CONFIDENCE THIS COMING WEEKEND AND NEXT WEEK PD. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 64 45 62 38 / 0 50 20 0 WACO, TX 67 47 66 37 / 0 30 20 0 PARIS, TX 61 42 58 35 / 0 60 20 0 DENTON, TX 64 44 61 37 / 0 60 10 0 MCKINNEY, TX 63 44 60 36 / 0 60 20 0 DALLAS, TX 64 46 62 39 / 0 50 20 0 TERRELL, TX 64 45 61 37 / 0 50 30 0 CORSICANA, TX 65 46 64 37 / 0 30 30 0 TEMPLE, TX 68 48 66 39 / 0 20 30 0 && .FWD WATCHES/WARNINGS/ADVISORIES... TX...NONE. && $$ /05 tx AREA FORECAST DISCUSSION...UPDATED FOR AVIATION NATIONAL WEATHER SERVICE FORT WORTH TX 520 AM CST TUE MAR 8 2005 .AVIATION... VFR NEXT 24 HOURS AS HIGH PRESSURE AT THE SURFACE MOVES EAST AND H5 SHORTWAVE ENERGY MOVES TOWARD N TEXAS FROM THE NW. COULD BE SOME TSRA AROUND TONIGHT...BUT MOISTURE APPEARS A BIT LIMITED. THUS...WILL NOT INCLUDE TSRA AT AIRPORTS. NW FLOW TO BECOME SW OVERNIGHT. && .SHORT TERM... BRIEF REPRIEVE TODAY AS FIRST COLD FRONT SURGES INTO THE GULF OF MEXICO...WITH SFC HIGH ANCHORING OVER THE SRN PLAINS. A COOL START TO THE DAY...BEFORE SFC HIGH SHIFTS EWD INTO LWR MS VALLEY THIS AFTN WITH BRIEF RETURN FLOW...AS ROCKIES LEE SIDE TROUGH DEEPENS IN RESPONSE TO IMPRESSIVE S/W IN NW FLOW ALOFT OVER NRN ROCKIES/PLAINS ATTM MOVES SWD WITH ANOTHER COLD FRONT ASSOCIATED WITH IT. COLD 500 MB TEMPS =< -20 DEG C NOTED PER LATEST RUC WITH THIS S/W. THIS SYSTEM TO ARRIVE ACROSS THE RED RIVER BY 03Z TONIGHT/AFTER AS 850-700MB LAYER MOISTURE INCREASES. LAPSE RATES TO BE IN/NEAR 7 DEG C/KM. WILL SLOW PREVIOUS FCST...WITH MOST ACTIVITY OCCURRING BETWEEN 06Z-18Z WED. ETA THE ODD MODEL OUT AND WILL FOLLOW GFS/UKMET /CANADIAN CONSENSUS ON HIGHER POPS...BEST NE. PREVIOUS FCST ALREADY HAS MARGINAL SEVERE HAIL THREAT HANDLED AND WILL HOLD THAT THOUGHT THIS FCST...AS 30-40 KT MID LVL FLOW AND AFOREMENTIONED MID LVL LAPSE RATES WELL SUFFICIENT ENOUGH FOR LOW-END SEVERE HAIL THREAT AND MORNING HWO WILL COVER THIS POTENTIAL. SYSTEM TO BE A QUICK-HITTER WITH FRONT CLEARING AREA WED AFTN WITH DRY/BREEZY/COOLER CONDS GOING INTO WED NIGHT. LEANED WITH COOLER MAV NUMBERS. && .LONG TERM... MORE AMPLIFIED 4-WAVE PATTERN REPLACES PREVIOUS...STAGNANT SPLIT FLOW PATTERN SEEN THE PAST FEW WEEKS HEADING INTO NEXT WEEKEND. SHOULD SEE WARM UP AGAIN THURS...BEFORE ANOTHER COLD FRONT ARRIVES THURS NIGHT/FRI MORNING. NW FLOW WILL CONTINUE HEADING INTO THE WEEKEND WITH ISOLATED/ELEVATED STORMS POSSIBLE AGAIN ACROSS NE 1/2 OF THE REGION AS S/W DRIVES IN FROM THE N ON FRI NIGHT. LOW CONFIDENCE HERE JUST LIKE TODAY WITH THE WILD CARD BEING MOISTURE AVAILABILITY. NICE WARM UP THIS WEEKEND IN RETURN FLOW... BEFORE COOL DOWN OCCURS EARLY NEXT WEEK WITH LOW POPS NORTH. AGAIN...STRESS VERY CONFIDENCE THIS COMING WEEKEND AND NEXT WEEK PD. && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 64 45 62 38 / 0 50 20 0 WACO, TX 67 47 66 37 / 0 30 20 0 PARIS, TX 61 42 58 35 / 0 60 20 0 DENTON, TX 64 44 61 37 / 0 60 10 0 MCKINNEY, TX 63 44 60 36 / 0 60 20 0 DALLAS, TX 64 46 62 39 / 0 50 20 0 TERRELL, TX 64 45 61 37 / 0 50 30 0 CORSICANA, TX 65 46 64 37 / 0 30 30 0 TEMPLE, TX 68 48 66 39 / 0 20 30 0 && .FWD WATCHES/WARNINGS/ADVISORIES... TX...NONE. && $$ /05 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1025 AM EST TUE MAR 8 2005 .UPDATE... VERY BUSY MRNG...CURRENT LOCATION OF SFC COLD FRONT FRONT NOW NEAR AKQ. SNOW FALLING IN CHO W/ SVR WX ACRS NE NC EXTREME SE VA. HAVE FOLLOWED RUC MODEL FOR TEMPS RAPIDLY COOLING FASTER THAN OTHER MDLS DEPICT. ADDED WINTER WX ADVSRY FOR NRN NECK/MD ZONES FOR 1-2 INCHES SNOW AS UPR Q VECTOR FORCING WILL REMAIN STRONG THROUGH ERLY/MID AFTN THAT FAR EAST. FOR METRO RIC WENT W/ ACCUMULATION ARND AN INCH (FOR GRASSY SFC). DON'T THINK IMPACT ON ROADS WILL BE THAT BAD AS SFC TEMPS SHOULD STAY AT OR SLIGHTLY ABOVE FREEZING FOR DURATION OF PRECIP. SEE WSWAKQ AND NPWAKQ FOR DETAILS ON WINTER WX ADVSRY AND WIND AVSRY. ___________PREV AFD BELOW_____________ COLD FRONT IS CURRENTLY PLOWING ACROSS WRN VA AND WRN NC...JUST ABOUT READY TO DROP E OF THE MNTS. PRE-FRONTAL SHOWERS HAVE OVERSPREAD MUCH OF THE REGION...AS TEMPS AHEAD OF THE FRONT REMAIN ON THE MILD SIDE (GENERALLY THROUGH THE 50S). WELL-DEFINED CONVEYOR BELT STRUCTURE ASSOCIATED WITH THIS SYSTEM. THE WARM CONVEYOR (AREAS OF PRE FRONTAL SHOWERS) IS CURRENTLY MOVING THROUGH ERN MD/VA/NC...WITH THE DRY SLOT LIFTING THROUGH WRN NC/VA AND AS FAR N AS WRN PA. LASTLY...BEHIND THE DRY SLOT IS A WELL-DEVELOP COLD CONVEYOR BELT ASSOCIATED WITH THE MAXIMUM MID LEVEL (700-500 MB) FRONTOGENESIS...JUST AHEAD OF THE MID LEVEL TROUGH/DEFORMATION AXIS. THE MAIN FORECAST CONCERNS TODAY WILL BE 1) THE STRENGTH OF SURFACE WINDS BEHIND THE FRONT...ALONG WITH THE POTENTIAL FOR SOME SNOW LATER THIS AFTN UNDERNEATH THE COLD CONVEYOR BELT/DEFORMATION AXIS. WITH RESPECT TO THE WINDS...STRONG COLD ADVECTION ALOFT WILL PROMOTE OPTIMAL VERTICAL MIXING (DEEPENING BOUNDARY LAYER) BY AFTERNOON... ESPECIALLY WHEN FACTORING THE NW DOWNSLOPE FLOW AND ITS EFFECTS ON ADDITIONAL SURFACE HEATING BOTH ADIABATICALLY AS WELL AS DIABATICALLY GIVEN INCREASED BREAKS IN THE CLOUD COVER (SOLAR HEATING). WINDS AT THE TOP OF THE CBL (CONVECTIVE BNDRY LAYER) ARE EXPECTED TO AVERAGE BTWN 40 AND 50 KTS...WITH THE HIGHEST ACROSS THE N-NE ZONES WHERE THE PRESSURE GRADIENT AND ISALLOBARIC COMPONENT WILL BE GREATEST. SO...HAVE HOISTED A WIND ADVISORY OVER THE LOWER ERN SHORE...NRN NECK AND MIDDLE PENINSULA...AND FAR NRN PORTIONS OF OUR CENTRAL VA COUNTIES IN LIGHT OF THE POTENTIAL FOR WIND GUSTS TO NEAR 50 MPH. AS FOR THE SNOW...THE PRIMARY FOCUS FOR CONCERN WILL BE ACROSS THE LOWER MD ERN SHORE...GIVEN A MORE PROLONGED PERIOD OF DEEPER WRAP-AROUND (CCB) MOISTURE...ALONG WITH LESS DOWNSLOPE DRYING IN THIS REGION (AS IS TYPICAL FARTHEST AWAY FROM THE SLOPES). WHILE DO ANTICIPATE A QUICK BURST OF SNOW SHOWERS...VERY WARM GROUND TEMPS EARLY ON ALONG WITH ONLY MARGINALLY COLD BNDRY LAYER TEMPS DURING THE AFTERNOON (MID-UPPER 30S)...EXPECT ONLY MINOR ACCUMULATIONS ON GRASSY SURFACES. THE PROBLEM...EVEN ACROSS THIS REGION...IS BY THE TIME THE AIRMASS AT LOW LEVELS IS SUFFICIENTLY COLD TO SUPPORT SNOW...THE BULK OF THE MOISTURE (QPF) WILL HAVE SHIFTED OFFSHORE. SO...OVER THE LOWER MD ERN SHORE THE FORECASTS WILL REFLECT LITTLE OR NO ACCUMULATION...OR BASICALLY LESS THAN A HALF INCH AS IS REFLECTED IN THE SNOW AMOUNT GRID FORECASTS. THIS CERTAINLY IS A SITUATION WHICH WILL BEAR WATCHING DURING THE AFTN. IF THE COLD AIR CAN COME IN SOONER (WHILE HEAVIER PRECIP AND ADDED DYNAMICAL COOLING TAKE PLACE)...COULD CERTAINLY ENVISION MORE APPRECIABLE ACCUMULATION EVEN WITH SURFACE TEMPS IN THE MID 30S. REMAINDER OF THE FORECAST...STILL KEEPING AN EYE ON THE NEXT CLIPPER SYSTEM SLATED FOR FRIDAY. AGAIN...LOW LEVEL THERMAL PROFILE WOULD SUPPORT THE POSSIBILITY OF SOME LIGHT SNOW OR RAIN/SNOW MIX AT THE ONSET IF THE MOISTURE WERE TO ARRIVE BEFORE DAWN. EVEN SO...FROM A CLIMATOLOGICAL PERSPECTIVE (ESPECIALLY IN MID MARCH)...A MORE NORTHERN TRACK OF THE MID LEVEL VORT LOBE...WITH THE SURFACE LOW AND DEEPER FORCING/MOISTURE EXPECTED TO TRACK N OF THE MASON-DIXON LINE...WOULD IMPLY LITTLE IF ANY WINTER WEATHER IMPACT OVER OUR FCST AREA. && .AVIATION...MVFR CONDITIONS IN SHRA AND BR TODAY. SOUTH TO SOUTHWEST SURFACE WINDS WILL GUST ABOVE 20 KTS THIS MORNING AHEAD OF COLD FRONT. COLD FRONT WILL CROSS REGION THIS MORNING WITH CONTINUED MVFR AND LOCALLY IFR CONDITIONS IN SHRA. BEHIND FRONT WINDS WILL SHIFT TO NORTHWEST AND CONTINUE GUSTY IN TIGHTENING GRADIENT. && .MARINE...GALE WARNING ALL COASTAL WATERS AND CHES BAY SOUTH OF SMITH POINT. SOUTH AND SOUTHWEST WINDS INCREASING AHEAD OF STRONG COLD FRONT. GALE FORCE WINDS CONTINUE BEHIND FROPS THIS MORNING WITH WINDS SHIFTING TO NORTHWEST...AND GRADIENT TIGHTENS AND GOOD CAA. SUSTAINED SPEEDS MAY BE MARGINAL BUT EXPECT FREQUENT GUSTS AOA 35 KTS. FOR CURRITUCK SOUND WILL KEEP SCA HEADLINE. WINDS/SEAS WILL DECREASE TONIGHT AND WEDNESDAY AS HIGH PRES BUILDS IN. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...WIND ADVISORY...FROM 11 AM TO 6 PM TODAY... MDZ021>025. NC...WIND ADVSRY 11AM TO 6 PM...NCZ012>017-030>032-102 VA...WIND ADVISORY...FROM 11 AM TO 6 PM TODAY... VAZ048-049-064-073>078-084>086-099-100. VAZ060>063-065>072-079>083-087>098. MARINE...GALE WARNING ALL ATLC CSTL WTRS FM FENWICK ISLAND TO CURRITUCK BEACH LIGHT...AND CHES BAY SOUTH OF SMITH POINT. SMALL CRAFT ADVISORY FOR CURRITUCK SOUND. && $$ SHORT TERM UPDATE...BROWN va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OFFICE MELBOURNE FL 215 AM EST WED MAR 9 2005 .DISCUSSION... 250MB JET AXIS REMAINING NORTH OF THE CWA WILL KEEP A STEADY STREAM OF MID/UPPER LEVEL CLOUDINESS AS VIEW BY LATEST IR SATELLITE LOOP. 00Z UPPER AIR SOUNDINGS SHOWED QUITE A MOISTURE GRADIENT BETWEEN KEY WEST/MIAMI AND CENTRAL FLORIDA. LATEST RUC80 AND NCEP ANALYSIS AND SURFACE OBS PLACE THE FRONTAL BOUNDARY THAT MOVE ACROSS CENTRAL FLORIDA TUESDAY BETWEEN SOUTHERN FLORIDA AND CUBA. WEAK IMPULSES ROUNDING THE BASE OF THE 500MB TROUGH AS IT DROPS DOWN THE LOWER MISSISSIPPI RIVER VALLEY START PULLING THE STATIONARY/COLD FRONTAL BOUNDARY NORTH AS A WARM FRONT DURING THE DAY. COMBINATION OF THE RIGHT REAR QUADRANT OF THE STRONG SOUTHERN STREAM JET MAX TO THE NORTH PROVIDING LARGE SCALE ASCENT OVER FLORIDA...ISENTROPIC LIFT AS THE WARM FRONT SLIDES NORTH WILL INCREASE RAIN CHANCES DURING THE DAY. ONLY LIMITING FACTOR IS THE LARGE MOISTURE GRADIENT OBSERVED IN THE 00Z SOUNDING BETWEEN SOUTH AND CENTRAL FLORIDA. SOUTHERLY WINDS IN THE LOWER/MID LAYERS PULLING MOISTURE NORTH DURING THE DAY/EVENING SHOULD INCREASE COVERAGE OF STRATIFORM LIGHT RAIN BEGINNING SOUTH BY THE AFTERNOON AND SPREAD NORTHWARD. APPROACHING 500MB TROUGH FROM THE WEST PUSHES THE MOISTURE AND WARM FRONT SOUTH OVERNIGHT WITH RAIN ENDING OVER THE NORTH TOWARD SUNRISE BUT LINGERING INTO THE DAYLIGHT HOURS OVER THE SOUTHERN SECTIONS. THURSDAY...GUIDANCE A BIT MORE PROGRESSIVE WITH SHRT WAVE MOVING THRU BASE OF EAST COAST TROF. MID/UL FLOW BECOMES MORE CONFLUENT AND SHOULD ALLOW FOR RAPID CLEARING. HAVE LIMITED PCPN TO THE FAR S DURING THE MORNING WITH DRYING MOVING IN FM THE NW. FRIDAY...LOW LVL RIDGE STAYS OVER THE WRN GULF AND MORE ENERGY ROTATES THRU ERN CONUS TROF. OH VLY LOW DEEPER THAN PREV MDL RUNS INDICATING A TIGHTER GRADIENT AND SLIGHTLY BETTER MOISTURE RETURN AHEAD OF NEXT CD FNT. THIS FEATURE TOO WILL BE MOISTURE STARVED BUT WILL CONTINUE VRY LOW POPS FOR BAND OF SHRA MOVING THRU FRI NIGHT ALONG WEAKLY CONVERGENT BNDRY. FORCING WILL BE BEST TO THE N AND FURTHER REFINEMENT MAY BE MADE TO REMOVE POPS TO THE S. SATURDAY...CAA WILL FOLLOW IN WAKE OF FNT MUCH OF THE DAY...ALTHO PTRN REMAINS VERY PROGRESSIVE WITH MID LVL FLOW BECOMING INCREASINLY ZONAL. LOW LVL RIDGE SLIDES ACROSS THE FL STRAITS BY SAT EVE SHUTTING DOWN CAA AND GRADIENT. SUNDAY/MONDAY...WRM UP FOR SUNDAY AS LOW LVL RIDGE MOVES OFF THE SE FL COAST AND HTS RISE SLIGHTLY. NEXT RIPPLE IN NRN STREAM PUSHES CD FNT THRU REGION ON MONDAY. MOISTURE BAND NARROWS AS IT PUSHES INTO CENTRAL FL BUT UPPER JET POSTION IS FVRBL. WILL ONLY ADD LOW CHC POPS. THRU MID NEXT WEEK...PTRN LOOKS MORE PROGRESSIVE THAN IT DID IN PREV GUIDANCE. WHILE FLAT RIDGE MAY POP UP OVER THE SE FOR SOME WARM WX INITIALLY...GFS CONTINUES MOVING THINGS ALONG WITH CUTOFF OVER THE WEST TRANSITIONING TO THE MIDDLE PART OF THE CTRY BY LATE IN THE WEEK. && .MARINE...MODERATE NORTHERLY WINDS PERSIST AS SURFACE HIGH BUILDS ACROSS THE GULF OF MEXICO AND FLORIDA TODAY/TONIGHT. SMALL CRAFT ADV CONDITIONS RETURN FRI NIGHT AHEAD OF NEXT COLD FRONT. NW FLOW BEHIND FNT ON SAT WILL WEAKEN RATHER QUICKLY AS RIDGE BUILDS EAST. && .FIRE WEATHER...DESPITE DRY AIR NEAR SFC INITIALLY...CLOUDS WILL LIMIT HEATING AND MOISTENING ESP OVER THE S WILL OCCUR WITH DEVELOPING ISENTROPIC LIFT. NW FLOW AND DRYING WILL RETURN ON THUR. ADJUSTED DEW PTS DOWN TO ACCOUNT FOR TRENDS THUR BUT STILL END UP WITH ONLY UP TO 2 HOURS OF RH 35 PCT OR BLO. WILL WAIT FOR ADDITIONAL TREND BEFORE ISSUING WATCH ON THUR. && .PRELIMINARY POINT TEMPS/POPS... DAB 58 45 66 46 / 40 50 10 0 MCO 58 45 69 48 / 50 60 10 0 MLB 61 45 66 50 / 60 60 10 0 VRB 64 46 68 48 / 60 70 10 0 && .MLB WATCHES/WARNINGS/ADVISORIES... ...NONE. && $$ SHORT TERM...WIMMER LONG TERM....BLOTTMAN fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 200 AM MST WED MAR 9 2005 .DISCUSSION...FORECAST CONCERNS FOCUS ON THE WINDS ONCE AGAIN FOR THURSDAY AFTERNOON. TODAY-FRIDAY...VORT MAX CURRENTLY TO THE NORTHWEST OF THE PACIFIC COAST WILL MOVE EAST ACROSS SOUTHERN CANADA TODAY BEFORE DIVING SOUTHEAST TONIGHT AND MOVING THROUGH THE NORTHERN AND CENTRAL PLAINS THURSDAY. THIS SYSTEM WILL EXIT OUR AREA THURSDAY NIGHT WITH FRIDAY CONTINUING TO FEATURE DEEP NORTHWEST FLOW ALOFT BETWEEN AN UPPER HIGH OFF THE CALIFORNIA COAST AND PERSISTENT LOW PRESSURE OVER THE GREAT LAKES. ETA/GFS AND 20KM/13KM RUC MODELS BOTH SHOW ADVISORY CRITERIA WINDS MID TO LATE AFTERNOON THURSDAY AS UPPER JET NOSES INTO THE AREA. SUSTAINED WINDS OF 30 MPH LOOK RATHER EASY TO ACHIEVE AND WARNING CRITERIA WINDS DONT LOOK OUT OF THE REALM MOSTLY NORTH OF INTERSTATE 70. PLENTY OF TIME TO LOOK THINGS OVER FOR ANOTHER MODEL RUN OR TWO SO WILL HIGHLITE THE WIND THREAT IN THE HWOGLD PRODUCT AND ALERT DAYSHIFT TO POTENTIAL HIGH WIND WATCH SCENARIO. TEMPERATURES WILL WARM THEN COOL THEN WARM AGAIN AS THE ABOVE MENTIONED WEATHER FEATURES MOVE THROUGH. AS THEY DO...NORTHWEST WINDS WILL INCREASE TO BREEZY/WINDY CRITERIA WITH POSSIBLE ADVISORY CRITERIA WINDS THURSDAY. THESE WINDS ARE MORE GRADIENT WINDS THEN COLD/WARM ADVECTION WINDS AND USING THE 3/6 HOUR PRESSURE RISES TO PINPOINT ADVISORY CRITERIA WIND AREA RATHER DIFFICULT. ONLY THREAT OF PRECIP CHANCES LOOKS TO BE WITH THE FRONTAL PASSAGE THURSDAY. TQ INDICES/TOTAL TOTALS AND MID LEVEL MOISTURE ARE FAVORABLE BUT THE LAPSE RATES ARENT. FOR NOW WILL LEAVE 10 POPS IN THE FORECAST. SATURDAY-SUNDAY...DGEX/GFS ARE FAIRLY SIMILAR IN BRINGING A COLD FRONT THROUGH THE AREA LATE IN THE DAY...PERHAPS AFTER TIME OF PEAK HEATING. HIGH PRESSURE SLIDES IN BEHIND THE FRONT SATURDAY NIGHT WITH QPF FROM THESE MODELS RATHER LIGHT. WILL UP THE POPS JUST A BIT BUT BELOW MENTIONING IN THE FORECAST AT THIS POINT. TEMPERATURES SUNDAY WILL BE COOLER AND POSSIBLY BELOW NORMAL FOR THE FIRST TIME IN QUITE AWHILE. CURRENT FORECAST HAS THINGS PRETTY WELL IN HAND AND IS IN TOLLERANCE WITH SURROUNDING OFFICES. MONDAY-TUESDAY...NO CHANGES MADE OTHER THEN ENSURING GRIDS REMAIN IN TOLLERANCE WITH SURROUNDING OFFICES. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 324 AM EST WED MAR 9 2005 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE SNOW POTENTIAL FOR TODAY AND TONIGHT. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A LONGWAVE TROUGH OVER EASTERN CANADA AND A RIDGE EXTENDING FROM THE NORTHERN ROCKIES INTO CENTRAL CANADA. A CLOSED LOW EMBEDDED IN THIS TROUGH IS OVER MAINE AND WEAK SHORTWAVE IS SHOWING UP OVER CENTRAL LOWER MICHIGAN...THE NORTHERN PLAINS...CENTRAL ONTARIO...AND NORTHWEST MANITOBA. SURFACE ANALYSIS INDICATE A BROAD RIDGE OVER MANITOBA AND THE NORTHERN PLAINS. ANOTHER WEAKER RIDGE IS OVER THE OHIO RIVER VALLEY. UPSTREAM A SURFACE LOW IS DEVELOP OVER NORTHEAST ALBERTA WITH AN ACCOMPANYING COLD FRONT THAT STRETCHES SOUTH THROUGH THE NORTHERN HIGH PLAINS. CLOSER TO HOME...AN 850MB THERMAL TROUGH OVER CENTRAL ONTARIO IS PRODUCING LAKE-850MB DELTA-T'S AROUND 20C. ETA12 CONTINUES TO DEPICT LOW LEVEL CONVERGENCE OVER THE NORTHERN LAKE SUPERIOR...AND ANTI-CYCLONIC FLOW AROUND THE NORTHERN PLAINS RIDGE IS KEEPING THE WINDS OUT OF THE NORTHWEST OVER THE FORECAST AREA. THESE THINGS TOGETHER CONTINUE TO GENERATE LAKE EFFECTS SNOWS BANDS OVER THE NORTH CENTRAL AND EASTERN U.P. WHICH ARE VERIFIED BY KMQT-88D AND SURFACE REPORTS. THE MID LEVEL LOW OVER MAINE WILL BECOME BETTER FOCUSED THROUGH THE DAY AND SHIFT NORTHWEST INTO WEST CENTRAL QUEBEC TODAY. THE ONTARIO TROUGH WILL BECOME EXTENDED AND STRETCH ACROSS THE U.P. WHILE THE NORTHERN PLAIN TROUGH WILL SHIFT INTO MINNESOTA. THE RIDGE OVER THE NORTHERN PLAINS WILL SLIDE INTO THE UPPER MISSISSIPPI RIVER VALLEY. THE SURFACE LOW WILL TRACK FROM ALBERTA INTO WEST CENTRAL MANITOBA DRAGGING THE COLD FRONT INTO THE NORTHERN PLAINS. THE WINDS WILL REMAIN WEAK AND OUT OF THE NORTHWEST. LOW LEVEL CONVERGENCE OVER THE NORTHERN PART OF THE LAKE WILL WEAKEN THROUGH THE DAY AS WELL. MEANWHILE...DRY COOLER AIR WILL ADVECT INTO THE UPPER GREAT LAKES REGION. THE MEAN 925-850MB RH WILL DIMINISH TO LESS THEN 70 PERCENT. 850MB THERMAL TROUGH WILL PUSH EAST DURING THE DAY... HOWEVER...THE 850MB TEMPERATURES WILL REMAIN AROUND -16C OVER THE WEST AND AROUND -18C OVER THE EAST. THE SURFACE WINDS AND LOW LEVEL RH SEEMS TO FOCUS THE LAKE EFFECT SNOWS OVER THE EASTERN ALGER...NORTHERN SCHOOLCRAFT... AND LUCE COUNTIES. THERE WILL STILL BE ENOUGH LOW LEVEL CONVERGENCE AND AVAILABLE MOISTURE TO DEVELOP SOME LAKE EFFECT SNOW SHOWERS OVER THE WEST EARLY AND THE LAKE EFFECT PRONE AREA OF THE EAST. PLAN TO KEEP THE LAKE EFFECT SNOW ADVISORY GOING UNTIL NOON. THE WEAK SHORTWAVE OVER MINNESOTA WILL SWEEP ACROSS THE FORECAST AREA INTO THE LOWER GREAT LAKES TONIGHT. THE SURFACE LOW WILL TRACK INTO NORTHEAST MINNESOTA...DRAGGING THE COLD FRONT INTO THE UPPER MISSISSIPPI RIVER VALLEY AND THE CENTRAL PLAINS. THE WINDS OVER THE UPPER MISSISSIPPI RIVER VALLEY WILL BACK SOUTH. DELTA-T'S WILL BE STRONG ENOUGH TO KEEP A FEW LAKE EFFECT SHOWERS OVER THE FAR EASTERN U.P. LOW LEVEL MOISTURE WILL INCREASE OVER THE FAR WEST. 275K ISENTROPIC ANALYSIS INDICATE FAIRLY SIGNIFICANT ASCENT OVER THE FORECAST AREAS. SINCE DRY AIR WILL BE IN PLACE...DO NOT EXPECT ANY SNOW WITH THIS NEXT SYSTEM UNTIL LATE TONIGHT OVER THE WEST. THE MID LEVEL LOW WILL CONTINUE TO BACK INTO THE REGION AND WILL BE OVER WEST CENTRAL QUEBEC ON THURSDAY. ANOTHER WEAK SHORTWAVE WILL RE-ORIENT ITSELF OVER THE FORECAST AREA. THE SURFACE LOW WILL BE MOVING OVER LAKE MICHIGAN. MODELS BEGIN TO DISAGREE ON THE TRACK. UKMET/ETA SEND THE LOW OVER CENTRAL LAKE MICHIGAN...WHILE GFS/ECMWF PLACE IT OVER THE CHI AREA BY SUNSET ON THURSDAY. THIS WILL IMPACT THE WIND STRENGTH AND DIRECTION. HPC FAVORS THE SOUTHERN TRACK SYSTEMS. I AGREE...SEE THEIR DISCUSSION FOR THE REASONING. THE HEAVIER PRECIPITATION WILL REMAIN WEST AND SOUTH OF THE FORECAST AREA...MORE INLINE WITH THE TRACK OF THIS SYSTEM. SHORTWAVE ENERGY AND MOISTURE WRAPPING AROUND THE LOW WILL PRODUCE A CHANCE OF SOME SNOW. A THERMAL TROUGH WILL REMAIN OVER CENTRAL ONTARIO...PRODUCE DELTA-T'S OVER LAKE SUPERIOR OF 15C. CONDITION LOOK FAVORABLE FOR SOME LAKE EFFECT SNOWS OVER THE EASTERN U.P. WHILE THE REST OF THE U.P. WILL BE CLOSER TO THE TREK OF THE LOW AND VULNERABLE TO THE SNOW OF FROM THE SYSTEM. COLD AIR WILL ADVECT INTO THE AREA BEHIND THE FRONT AND SURFACE LOW. THE MID LEVEL LOW WILL BACK INTO SOUTHERN JAMES BAY THURSDAY NIGHT WHILE...WEAK SHORTWAVE ENERGY REMAINS OVER THE AREA. STILL FOLLOWING THE GFS/ECMWF...PLACING THE SURFACE LOW OVER EASTERN OHIO. WINDS SHOULD BE WEAKER AND OUT OF THE NORTH. DELTA-T'S OVER LAKE SUPERIOR WILL BE AROUND 14C. CONDITIONS REMAIN FAVORABLE FOR LAKE EFFECT SNOWS OVER THE NORTH AND SYSTEM SNOW OVER THE SOUTH. COLD AIR WILL CONTINUE TO POUR INTO THE FORECAST AREA. THE MID LEVEL LOW WILL REMAIN OVER JAMES BAY ON FRIDAY. A WEAK SHORTWAVE WRAPPING AROUND THIS LOW WILL BE OVER THE UPPER GREAT LAKES. SURFACE FEATURE MOVE THE SURFACE LOW INTO NEW ENGLAND...WHILE A LOBE OF THIS LOW SWEEPS THROUGH LOWER MICHIGAN. LOW LEVEL MOISTURE WILL CONTINUE TO CONTRIBUTE TO A CHANCE OF LIGHT SNOW SHOWERS OVER THE FORECAST AREA. THE MID LEVEL LOW WILL INCH WEST INTO CENTRAL ONTARIO. A WEAK SHORTWAVE WILL SWING THROUGH NORTHEAST WISCONSIN. Q-VECTOR ANALYSIS SHOWING THE THE SHORTWAVE ENERGY WILL REMAIN OVER THE AREA. A WEAK SURFACE RIDGE WILL EDGE INTO THE UPPER MISSISSIPPI RIVER VALLEY. GFS STILL INDICATE THAT THE AIR MASS OVER THE REGION WILL REMAIN MOIST ENOUGH TO PRODUCE SOME SNOWS SHOWERS. && .MQT...WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING IN EFFECT FOR LAKE SUPERIOR. LAKE EFFECT SNOW ADVISORY UNTIL 17Z WEDNESDAY MIZ006-007-085. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 320 AM EST WED MAR 9 2005 .SHORT TERM...FOR TODAY BROAD SURFACE CYCLONIC FLOW TODAY...AS AT 500 MB REINFORCED TROUGHING OVER FORECAST AREA PINWHEELS AROUND EASTERN CANADIAN LOW. WEAK 700 TO 500 MB QVECTOR CONVERGENCE TODAY GIVEN A BIT OF DIFFERENTIAL PVA...OTHERWISE VERY LITTLE IN WAY OF FORCING. AGAIN TODAY THOUGH...WITH BROAD THERMAL TROUGH STILL IN PLACE OVER THE AREA...AND WITH MODEST LOW LEVEL MOISTURE TO WORK WITH...EXPECT STEEP LOW LEVEL LAPSE RATES THIS AFTERNOON WITH DEVELOPMENT OF SNOW SHOWERS. ALSO HELPING TODAY WILL BE FACT THAT MEAN LOW LEVEL WINDS WILL HAVE A LITTLE WESTERLY COMPONENT...ENABLING SOME LAKE MICHIGAN INFLUENCE TO ENTER IN. GIVEN SAME AIR MASS IN PLACE...EXPECT SIMILAR TEMPERATURES TO THOSE OF YESTERDAY. WILL WORD FORECAST AS SLIGHT CHANCE OF FLURRIES THIS MORNING BUT SCATTERED LIGHT SNOW SHOWERS THIS AFTERNOON. CLOUDS ON THE INCREASE AS THE DAY WEARS ON. && .LONG TERM... WEDNESDAY NIGHT THROUGH TUESDAY OUR MAIN PLAYER WAS CURRENTLY TRACKING ACROSS NORTHERN ALBERTA AND BASED ON H2O VAPOR SATELLITE ANALYSIS...THIS WAVE DOES LOOK STRONGER. NOW OVERLAY OF THE VARIOUS MODELS AT 06Z...ONE WOULD HAVE TO GIVE A SLIGHT NUDGE TO THE NAM, HOWEVER DOWNSTREAM RIDGE AMPLIFICATION WOULD FAVOR MORE OF THE ECMWF/WRFXX/GFS. NEEDLESS TO SAY, THE VERDICT IS STILL OUT BUT AFTER EXTENSIVE COLLABORATION WITH NCEP FORECASTERS... WE WILL FAVOR THE ECMWF WHICH IS VERY CLOSE TO OUR LOCALLY PRODUCED WRFXX. STARTING OFF WEDNESDAY EVENING, RESIDUAL DIURNAL FLURRIES WILL TAPER OFF OVERNIGHT AND WEAK SHORT WAVE RIDGING ALOFT AT 850-700MB OOZES OVERHEAD. WITH A WESTERLY WIND AND 850MB TEMPS OVER LAKE MICHIGAN REMAIN DOWN INTO THE NEGATIVE TEENS...WE COULD SEE SOME STRATO-CU FROM TIME TO TIME BUT HIGHER LEVEL CLOUDS WILL BE ADVECTING FROM OUR UPSTREAM SYSTEM LATE TONIGHT. SO AMPLE TIME FOR TEMPERATURES TONIGHT TO DROP BACK INTO THE TEENS. THURSDAY LOOKS LIKE A DRY START WITH A WHITE ENDING AS TIMING PER THE ECMWF/WRFXX POINTS TOWARD LIGHT SNOW ARRIVING BY LATE AFTERNOON. 280K ISENTROPIC LIFT RAPIDLY INCREASES AFTER 18Z ALONG WITH LOWERING CPD/S TOWARD 21Z. THE FIRST AREAS TO LIKELY SEE THE SNOW WILL BE ALONG AND SOUTH OF M59 THEN SPREAD FURTHER NORTH LATER IN THE DAY. SURFACE LOW TRACKS TOWARD THE VICINITY OF CHICAGO BY 00Z. DPROG/DT OF THE GFS POINTS TOWARD A LITTLE FURTHER NORTH SURFACE TRACK WHICH AGAIN IS CLOSER AGREEMENT WITH THE ECMWF AND LOCALLY PRODUCED WRFXX. THIS WILL BE VERY IMPORTANT TO HOW MUCH SNOW FALLS DURING THE EVENING HOURS THURSDAY. WITH SPECIFIC HUMIDITIES ON THE ORDER OF 1-2 G/KG IN THE 850-700MB LAYER AND BROAD SYNOPTIC LIFT WITH THE APPROACH OF THE TROF AXIS, WE WILL CONTINUE WITH THE LIKELY POPS FOR THE FIRST HALF OF THE NIGHT. QPF FROM THE WRFXX SHOWS POINTS TOWARD 0.15" TOWARD THE MICHIGAN STATE LINE WITH JUST UNDER HALF AS MUCH ACROSS THE FAR NORTH CWA. BASED ON THE CLIMATOLOGY OF SNOW RATIOS OF 12:1...UP TO 2" NEAR THE BORDER WITH LESS THAN 1" UP NORTH. MOST OF THE ACCUMULATING SNOWFALL WILL LIKELY END AFTER MIDNIGHT WITH THE PASSAGE OF THIS TROF AND DEPARTING SURFACE LOW TOWARD PITTSBURGH BY SUNRISE FRIDAY. FRIDAY REMAINS QUITE A QUESTION MARK AS ADDITIONAL SHORT WAVE ENERGY DIVES SOUTHEAST INTO THE UPPER MISSISSIPPI RIVER VALLEY AMPLIFYING THE TROF TOWARD FRIDAY EVENING. FRANKLY, MODELS ARE ALL OVER THE BOARD WITH DETAILS THAT ARE HARD TO RESOLVE. CONSENSUS, EXCLUDING THE NAM, POINT TOWARD A NARROW SHORT WAVE RIDGING FRIDAY MORNING WITH ADDITIONAL SNOW SHOWERS BY AFTERNOON. WE WILL TRY TIMING THIS WITH A CHANCE OF SNOW SHOWERS IN THE MORNING THEN BECOMING SCATTERED IN THE AFTERNOON. THIS TROF AXIS AND DEVELOPING LOW PRESSURE AT THE SURFACE WILL KEEP UNSETTLED CONDITIONS ACROSS THE STATE FRIDAY NIGHT INTO MOST OF THIS WEEKEND. TEMPERATURES THROUGH THE PERIOD WILL REMAIN BELOW NORMAL...AND WE COULD LIKELY SAY THAT THROUGH THE THE MIDDLE OF THIS MONTH! && .AVIATION... ISSUED AT MIDNIGHT NORTHWESTERLY FLOW IS KEEPING THE LAKE EFFECT ACTIVITY CONFINED MAINLY TO THE LAKE MICHIGAN SHORELINE. GIVEN THE VERY DRY AIR OVER THE REGION... SKIES SHOULD BE MOSTLY CLEAR OUTSIDE OF THE LAKE EFFECT. BASED ON THE LAKE CLOUDS OVER SOUTHERN LAKE MICHIGAN... LOW LEVEL WINDS LOOK TO BE A LITTLE MORE WESTERLY THAN INDICATED BY THE ETA. THE RUC SEEMS TO BE HANDLING THE LOW LEVEL FLOW A LITTLE BETTER. THIS FLOW MAY STILL ALLOW SOME STRAY LAKE CLOUDS TO WORK THEIR WAY INTO THE SOUTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT. && .DTX WATCHES/WARNINGS/ADVISORIES... .MI...NONE. .LAKE HURON...NONE. .LAKE ST CLAIR...NONE. .MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...DWD LONG TERM...BGM AVIATION...SC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1200 AM EST WED MAR 9 2005 .AVIATION... NORTHWESTERLY FLOW IS KEEPING THE LAKE EFFECT ACTIVITY CONFINED MAINLY TO THE LAKE MICHIGAN SHORELINE. GIVEN THE VERY DRY AIR OVER THE REGION... SKIES SHOULD BE MOSTLY CLEAR OUTSIDE OF THE LAKE EFFECT. BASED ON THE LAKE CLOUDS OVER SOUTHERN LAKE MICHIGAN... LOW LEVEL WINDS LOOK TO BE A LITTLE MORE WESTERLY THAN INDICATED BY THE ETA. THE RUC SEEMS TO BE HANDLING THE LOW LEVEL FLOW A LITTLE BETTER. THIS FLOW MAY STILL ALLOW SOME STRAY LAKE CLOUDS TO WORK THEIR WAY INTO THE SOUTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT. && .SHORT TERM... TONIGHT AND WEDNESDAY A QUIET BUT COLD STRETCH OF WEATHER IS IN STORE FOR THE SHORT TERM. AFTERNOON HIGH TEMPS TODAY ARE WITHIN A FEW DEGREES OF RECORD LOW MAXES FOR MARCH 8TH AND TONIGHT'S LOWS WILL BE IN THE SINGLE DIGITS IN LOCATIONS SHELTERED FROM A LIGHT GRADIENT WIND. HOWEVER, RECORD LOWS LOOK SAFE AS ALL ARE NEAR OR BELOW ZERO FOR THE 8TH AND 9TH. WITH THE LOSS OF DAYTIME HEATING, NEUTRAL NW LOW LEVEL FLOW WILL LEAD TO A CLEARING TREND THIS EVENING, ESPECIALLY AROUND THE TRI CITIES, FLINT, AND THUMB. LOCATIONS AROUND DETROIT AND THE OHIO BORDER WILL BE IN LINE FOR SOME STRATOCU FROM LAKE MICHIGAN AS THE LOW LEVEL FLOW BACKS TO JUST NORTH OF WEST. THE UPPER FLOW WILL BE CONFLUENT TO START THE EVENING BUT AN UPPER TROF WILL SWING THROUGH THE GREAT LAKES, ASSOCIATED WITH THE DEVELOPING WAVE OVER THE PLAINS. THIS WILL ATTEMPT TO REINFORCE THE COLD AIR IN LOWER MICHIGAN TOWARD SUNRISE AND ON WEDNESDAY. THE 12Z MODELS SUPPORT THIS TO VARYING DEGREES. THE GFS AND LOCAL WRF SHOW LESS INFLUENCE FROM LAKE MICHIGAN IN TERMS OF PRESSURE FALLS OVER SW LOWER COMPARED TO THE NAM12 AND EVEN THE NGM. SUSPECT AT LEAST A COMBINATION OF LAKE TROFFINESS AND SURFACE REFLECTION TO BE THE CASE, WHICH WILL LEAD TO A CHANCE OF SNOW SHOWERS WHEN ADDED TO DIURNAL HEATING ON WEDNESDAY. EVEN WITH THE MARCH SUN, PREFER HIGH TEMPERATURE GUIDANCE IN THE LOWER TO MID 20S BASED ON TODAY'S PERFORMANCE. && .LONG TERM... WEDNESDAY NIGHT THROUGH TUESDAY THROUGH SUNDAY...WE REMAIN UNDER NORTHWEST FLOW WITH SEVERAL SHORTWAVES DROPPING DOWN ACROSS THE AREA. THE FIRST OF THESE IS EXPECTED TO CLIP NORTHERN LOWER AND THE THUMB WEDNESDAY NIGHT BUT WILL BE LIMITED BY A DRY ATMOSPHERE ABOVE 850MB. HAVE A CHANCE OF SNOW SHOWERS NORTH OF I-94 AFTER MIDNIGHT ON WEDNESDAY BUT NOT EXPECTING MORE THAN A DUSTING. LAKE EFFECT SNOW SHOWERS SHOULD DO WELL OVER THE EAST CENTRAL PORTION OF LAKE HURON AND OVER ONTARIO AS 850MB TEMPS DROP DOWN TO -18C GENERATING AT LEAST 400 J/KG OF LAKE INDUCED CAPE. THESE SNOW SHOWERS OVER THE LAKE SHOULD END THURSDAY MORNING AS TEMPS WARM LOWERING INVERSION HEIGHTS AND WINDS BACKING AHEAD OF THE NEXT SYSTEM. THE NEXT WAVE MOVING OVER THE AREA THURSDAY EVENING WILL BE A LITTLE STRONGER. MODELS STRUGGLING A BIT ON THE TRACK OF THE SURFACE LOW AHEAD OF THIS WAVE. THE GFS HAS BEEN TRENDING FURTHER SOUTH WITH THE LOW MOVING FROM ILLINOIS ACROSS THE OHIO RIVER VALLEY. WRFXX IS SIMILAR TO GFS WITH THE TRACK OF THE SYSTEM WHILE ECMWF/GEM ARE A LITTLE FURTHER NORTH. NAM IS THE FURTHEST NORTH WITH A TRACK ACROSS CENTRAL LOWER BEFORE BEING ABSORBED BY THE HUDSON BAY LOW ON FRIDAY. PREFER A SURFACE LOW TRACK BLENDING THE ECMWF/WRFXX/GFS WHICH SEEMS TO BE THE GREATEST CONSENSUS. WITH THAT IN MIND THE IMPLICATIONS FOR THE FORECAST ARE THAT WE WILL STAY IN THE COLD SECTOR THE ENTIRE TIME AND MISS THE BEST PRECIP TO THE SOUTH...OVER INDIANA AND OHIO. LIFT ON 275K ISENTROPIC SURFACE SHOWS A LITTLE BIT OF WARMING GIVING OUR SOUTHERN COUPLE TIERS OF COUNTIES A DECENT SHOT AT LIGHT PRECIP THURSDAY AFTERNOON. THEN OVERNIGHT GFS/WRFXX BOTH SHOW AN AREA OF GOOD 850-500MB FRONTOGENESIS ROTATING ACROSS THE MI/IN/OH BORDER OVERNIGHT SO EXPECTING UP TO A COUPLE INCHES OF SNOW ACROSS SOUTHEASTERN MI. AT THIS TIME...MODELS IN FAIRLY GOOD AGREEMENT ABOUT A REINFORCING SHORTWAVE DROPPING DOWN ACROSS LOWER MICHIGAN FRIDAY NIGHT. AS A SURFACE TROUGH LINGERS OVER THE AREA FROM THE PREVIOUS SYSTEM NOW AT THE EAST COAST...HAVE ADDED A CHANCE OF SNOW SHOWERS TO FORECAST. SHORTWAVE TIMING IS STILL SUBJECT TO CHANGE THROUGH THE WEEKEND AS MODELS STRUGGLE WITH THESE SMALLER FEATURES. AS WE HEAD INTO NEXT WEEK...MODELS HINTING AT A BIT OF A PATTERN CHANGE AS A SHORTWAVE DROPS DOWN INTO THE PACIFIC NORTHWEST CAUSING MORE ZONAL FLOW OVER THE EASTERN PART OF THE COUNTRY. IF THIS PANS OUT...LOOK FOR A GRADUAL WARMING IN TEMPS INTO NEXT WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... .MI...NONE. .LAKE HURON...NONE. .LAKE ST CLAIR...NONE. .MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION/UPDATE...SC SHORT TERM...BT LONG TERM...KEK mi AREA FORECAST DISCUSSION...UPDATED AVIATION FOR 06Z TAF NATIONAL WEATHER SERVICE SPRINGFIELD MO 1130 PM CST TUE MAR 8 2005 .DISCUSSION... FAIRLY POTENT SHORT WAVE EVIDENT ON LATEST WATER VAPOR IMAGERY NEAR SOUTHEAST KANSAS LATE THIS EVENING. WEAK SURFACE REFLECTION AROUND TULSA OKLAHOMA WITH A SHARP WIND SHIFT TO THE NORTH/NORTHWEST MOVING SOUTHEAST ACROSS EASTERN KANSAS/NORTH CENTRAL OKLAHOMA. RUC ANALYSIS IS INITIALIZING THE SHORT WAVE TOO FAR WESTWARD WHICH WOULD TRANSLATE THE PRECIPITATION FIELD/STRONGER VERTICAL MOTION FURTHER NORTHEAST. LATEST FORECAST BY THE RUC INDICATED THE HEAVIEST PRECIPITATION FIELD WILL BE IN FAR SOUTHWEST MISSOURI BETWEEN JOPLIN AND BRANSON. THERMO PROFILERS STILL INDICATE A MOSTLY RAIN EVENT IN FAR SOUTHWEST MISSOURI BEFORE COLDER AIR MOVES IN AROUND 12Z. AROUND SPRINGFIELD...CRITICAL THERMO FIELDS HAVE MORE OF A SNOW PROFILE BY 12Z...BUT A MIXTURE OF RAIN AND SNOW WILL LIKELY DEVELOP AS EVAPORATIVE COOLING TAKES PLACE BETWEEN 06-09Z. THIS WAVE QUICKLY MOVES OUT OF THE REGION BY 15Z WITH RESIDUAL MOISTURE NEAR 900-800MB HOLDING MORE CLOUD COVER THROUGH THE AFTERNOON. JLT && .AVIATION... HAVE BROUGHT IN LOWER MVFR CEILINGS BY 09Z WITH ISOLATED HIGH IFR CEILINGS/VISIBILITIES BETWEEN 09-12Z AS THE MAIN UPPER VERTICAL MOTION MOVES OVER THE REGION. AS PREVIOUSLY STATED ABOVE...THERMO FIELDS SEEM TO INDICATE A TURN OVER TO SNOW IN KSGF BY 10Z. KJLN WILL LIKELY SEE MOSTLY RAIN BUT A TEMPORARY PERIOD OF A MIXTURE BETWEEN 09-12Z AS COLDER AIR WORKS ITS WAY IN. VFR CEILINGS WILL PREVAIL AFTER 16-18Z. JLT && .SGF WATCHES/WARNINGS/ADVISORIES... .MO...NONE. .KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 330 AM CST WED MAR 9 2005 .CURRENT OBSERVATIONAL OVERVIEW... 06Z SURFACE ANALYSIS DEPICTED LARGE DOME OF HIGH PRESSURE OVER AREA WITH RESULTANT LIGHT AND VARIABLE SURFACE FLOW. FARTHER UPSTREAM NEXT SURFACE TROUGH WAS BEGINNING TO TAKE SHAPE OVER ALBERTA PROVINCE WITH RESPECTABLE PRESSURE FALLS AHEAD OF FEATURE ACROSS SASK PROVINCE. LATEST WATER VAPOR IMAGERY/RUC ANALYSIS SHOWED NEXT SHOT OF SHORTWAVE ENERGY FOR AREA TO CONTEND WITH ENTERING BRITISH COLUMBIA WITH ASSOCIATED POWERFUL 130 KT UPPER LEVEL JET RIDING OVER TOP OF WESTERN CONUS UPPER LEVEL RIDGE. .FORECAST DETAILS... ETA/GFS SHOWING DIFFERENCES IN HANDLING OF NEXT LOW PRESSURE TROUGH TO AFFECT REGION. PREFER MORE WESTERN GFS SOLUTION WITH TROUGH/LOW IN LIGHT OF DEEPENING/RETROGRESSIVE NATURE TO OVERALL LONGWAVE TROUGH OVER CONUS. IN ADDITION APPEARS THAT GFS INITIALIZED BETTER WITH SURFACE AND UPPER LEVEL FEATURES AT 00Z/06Z. .TODAY-THURSDAY... HIGH PRESSURE DEPARTS REGION TODAY WITH COMMENCEMENT OF WAA PATTERN ON BACKSIDE OF FEATURE HELPING TO BOOST MERCURY TO NEAR THE FREEZING MARK ACROSS AREA. MEANWHILE LOW PRESSURE OVER NORTHERN ALBERTA PROVINCE PROGGED TO DROP SOUTHEAST AND DEEPEN AS BRITISH COLUMBIA UPPER LEVEL ENERGY AND JET DYNAMICS ENTERS PICTURE AND INTERACTS WITH FEATURE. PROJECTED LOW PRESSURE TRACK FROM GFS TAKES SYSTEM ACROSS THE NORTHERN RED RIVER VALLEY INTO CENTRAL MINNESOTA BY 12Z THURSDAY. ON THIS PROJECTED TRACK EXPECT A RATHER LARGE SWATH OF WARM ADVECTION/ISENTROPIC LIFT INDUCED SNOWS TO FALL FROM EASTERN NORTH DAKOTA INTO MINNESOTA LATE THIS AFTERNOON/EVENING INTO EARLY THURSDAY. ON PROJECTED PATH OF LOW CENTER EXPECT THE HIGHEST QPF/SNOW ACCUMULATION VALUES TO FALL IN MINNESOTA TO LEFT OF TRACK OF LOW WHERE STRONGER LARGE SCALE ASCENT I.E. Q-VECTOR CONVERGENCE AND DIVERGENCE OF Q WILL BE MAXIMIZED. IN THOSE LOCATIONS A GENERAL 3 INCH SNOWFALL IS POSSIBLE. ELSEWHERE WILL GO WITH ABOUT AN INCH. REMAINDER OF THURSDAY SHOULD BE UNSETTLED AS RESIDUAL CYCLONIC FLOW/DEEPENING PRESSURE GRADIENT ON BACKSIDE OF SYSTEM RESULTS IN WINDY CONDITIONS ALONG WITH LINGERING LIGHT SNOWS. APPEARS SOME TYPE OF HEADLINE WILL BE NEEDED FOR THURSDAY WIND ADVISORY VS WINTER WEATHER ADVISORY WILL BE THE DILEMMA. WILL ALLOW DAYCREW TO INGEST FURTHER GUIDANCE/WATCH EVENT UNFOLD IN MAKING FINAL CALL ESPECIALLY SINCE THE PERIOD OF CONCERN IS NOT UNTIL THURSDAY I.E. 3 PERIOD. .EXTENDED... PATTERN CONTINUES TO LOOK UNSETTLED AS REGION STAYS UNDER INFLUENCE OF STRONG POLAR VORTEX WITH AMPLIFIED NORTHWEST FLOW PROMOTING BELOW NORMAL TEMPERATURES/ALONG WITH PERIODIC LIGHT SNOW CHANCES WITH SHORTWAVE INTERACTION. && AVIATION... EXPECT GENERALLY VFR CIGS TODAY TO GIVE WAY TO MVFR BY LATE AFTERNOON WITH EMBEDDED AREAS OF IFR CIGS/VSBYS TONIGHT AND THURSDAY IN FALLING AND BLOWING SNOW. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ BERG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 530 AM CST WED MAR 9 2005 .DISCUSSION... NORTHWEST FLOW CONTINUES INTO NEXT WEEK KEEPING TEMPS BELOW NORMAL THRU AT LEAST MONDAY. IN THE SHORTTERM TEMPS SLOW TO DROP OFF EARLY THIS MORNING AND STILL RUNNING IN THE UPPER TEENS TO LOWER 20S. EXCEPT PASSING CIRRUS NOT MUCH CLOUD COVER TO AID TEMPS FROM FALLING SO LOWER TO MID TEENS BY MORNING STILL ON TRACK. NO SIGNIFICANT CHANGE IN PATTERN TODAY...LITTLE CHANGE IN 850MB TEMPS...MAYBE A FEW CU AND HIGHS A FEW DEGREES WARMER THAN TUES...REACHING THE LOWER 30S. MODELS CONTINUE TO DIFFER ON TRACK OF NEXT SYSTEM MOVING ACROSS THE LAKES REGION THURSDAY WITH THE GFS COOLER AND FARTHER SOUTH. THE GFS HAS BEEN CONSISTENT RUN TO RUN AS HAS THE NAM. THE GFS HAS BEEN DOING BETTER RECENTLY BUT THE NAM WOULD SUGGEST ONLY FLURRIES OR A SHORT PERIOD OF LIGHT SNOW. THE GFS ON THE OTHER HAND WOULD SUPPORT LIKELY POPS AND MAYBE AN INCH OF ACCUMULATION ACROSS THE FAR NORTH ON THURS. PLAN ON GOING LIKELY ACROSS THE NORTHERN TIER OF COUNTIES OF THE CWA AND MENTION UP TO AN INCH THERE. OTHERWISE WILL KEEP CHANCE POPS GOING ELSEWHERE AS WELL AS A RAIN/SNOW MIX ACROSS THE SOUTH. THIS SYSTEM SHIFTS EAST THURS NIGHT LEAVING A LINGERING CHANCE OF SNOW THURS NIGHT THEN WEAK IMPULSES CONTINUE TO ROUND UPPER TROF SO FLURRIES/SNOW SHOWERS FRI/SAT ON TRACK. ANOTHER QUICK MOVING LOW DIVES ACROSS THE PLAINS SATURDAY...BRINGING SOME VERY COLD AIR... 850MB TEMPS MAYBE AS LOW AS -22C BY SUNDAY AFTERNOON. EVEN IF IT ISN/T THIS COLD WHEN IT ARRIVES...TREND IS COLDER FOR LONGER. SO HAVE DROPPED HIGHS AND LOWS SEVERAL DEGREES OVER THE WEEKEND BUT NOT QUITE AS LOW AS NEW MEX NUMBERS. && .AVIATION... HIGH PRESSURE OVER THE GREAT PLAINS WILL BE THE DOMINATE FEATURE FOR THE NEXT 18 HOURS. THE HIGH WILL DRIFT SOUTH AS A LOW MOVE INTO MINNESOTA BY 12 UTC THURSDAY. EXPECT THE WIND TO SHIFT TO THE SOUTH LATE TONIGHT. WE ALSO EXPECT MORE CLOUDS BUT WILL FORECAST VFR CEILINGS. BY 12 UTC 6000 FT TO 9000 FT BROKEN CEILINGS WILL BE IN NORTHEAST ILLINOIS AND NORTHWEST INDIANA. USED A COMPROMISE OF THE GFS AND NAM MODELS BEYOND 9 HOURS AND USED THE WORKSTATION ETA AND RUC FOR THE FORECAST UP TO 9 HOURS. && LOT...WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LK MI...NONE. $$ il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE STATE COLLEGE PA 953 AM EST WED MAR 9 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... PARTLY TO MOST SUNNY AND COLD ACROSS A LARGE PERCENTAGE OF THE REGION THIS MORNING. THE EXCEPTION WAS LOCATIONS AFFECTED BY A NARROW...BUT LONG BAND OF SNOW SHOWERS EXTENDING FROM THE NW MTNS THE MID SUSQ VALLEY AND SCHUYLKILL COUNTY. THIS SNOW SHOWER BAND HAS ITS ORIGIN OVER ERN LAKE SUPERIOR...WITH A LONG FETCH ACROSS LA HURON AND EASTERN LAKE ERIE. 09Z RUC SHOWS NEARLY STEADY STATE LLVL WIND/THERMAL STRUCTURE THROUGH 21Z TODAY. SO ALTHOUGH THE BAN SHOULD BECOME MORE CELLULAR (ESP ACROSS THE NCENT MTNS AND CENTRAL SUSQ VALLEY) BY EARLY THIS AFTERNOON UNDER THE STRENGTHENING MARCH SUN...THERE WILL BE PLACES THAT RECEIVE ANOTHER COATING TO ONE INCH OF ACCUMULATION TODAY. HOURLY GRIDDED TEMPS ON TRACK WITH CURRENT OBS...AND MAXS TODAY WILL WORK OUT BETWEEN MAV...AND NOTABLY COOLER ETA MOS VALUES. INCREASED THE CHC FOR SCT SNOW SHOWERS ACROSS THE NORTH TONIGHT AS A WEAK SHORT WAVE MOVES SE ACROSS THAT AREA. THIS ADJUSTMENT ALSO BLENDS BETTER WITH BGM AND BUF POPS NEAR THE PA/NY BORDER. && .AVIATION... MAINLY VFR CONDITIONS TODAY/THIS EVENING...BUT ISOLATED IFR CLOUDS AND VSBYS IN SNOW SHOWERS WILL OCCUR FROM NEAR KBFD...SE TO VCNTY OF KIPT AND KSEG. && .PREVIOUS DISCUSSION... (ISSUED 255 AM EST WED MAR 9 2005) SHORT TERM (TODAY)... FRIGID AIR MASS FOR THIS TIME OF YEAR ENTRENCHED ACROSS CENTRAL PA TODAY. MARGINAL INVERSION HEIGHTS TO AROUND 4000 FEET AND CONTD NORTHWEST FLOW WITH A LAKE HURON CONNECTION SHOULD KEEP SCATTERED SNOW SHOWERS AND FLURRIES GOING ACROSS THE CENTRAL AND NORTHERN MOUNTAINS AND LAUREL HIGHLANDS TODAY. NOT EXPECTING ANY SIGNIFICANT OR WIDESPREAD ACCUMULATIONS...BUT SOME SPOTS IN THE LAURELS MAY SEE FRESH COATINGS OF SNOW FROM TIME TO TIME THROUGHOUT THE DAY. BRISK NORTHWEST WINDS WL MAKE IT DIFFICULT TO MEASURE WHAT SNOW DOES FALL AS THERE WILL BE QUITE A BIT OF BLOWING. KEPT HIGH TEMPS CLOSE TO OR SLIGHTLY BELOW MAV NUMBERS FOR TODAY LONG TERM (TONIGHT THROUGH TUESDAY)... A DECREASE IN LE -SHSN EXPECTED TONIGHT AND THURSDAY AS WINDS TURN MORE WESTERLY AND WEAK WAA COMMENCES. MAIN FOCUS FOR THE LATE WEEK IS THE WELL ADVERTISED STRONG CLIPPER SYSTEM TO AFFECT PA ON FRIDAY. GLOBAL MODEL SOLUTIONS (GFS AND ECMWF) HAVE BEEN QUITE CONSISTENT IN BRINGING SFC LOW DIRECTLY THROUGH CENTRAL PA...WHILE NAM KEEPS CENTER OVER SOUTHERN QUEBEC. MODEL QPF IN AGREEMENT FOR A GENERALLY LIGHT SNOWFALL EVENT FOR CENTRAL PA FRIDAY. RAISED POPS TO LIKELIES GIVEN THE OVERALL CONSISTENCY OF GFS/ECMWF RUNS AND HIGH PROBABILITY OF MEASURABLE PRECIPITATION SHOWN BY 00 UTC MREFS (GREATER THAN 90% CERTAINTY OF .10" OR MORE). IT APPEARS THIS SYSTEM WILL REDEVELOP OFF OF THE VA COAST ON SATURDAY AND BOMB OUT AS IT HEADS NORTHWARD EAST OF NEW ENGLAND THIS WEEKEND AND RETROGRADING INTO ERN QUEBEC SUN-MON. REMAINDER OF THE SUN-TUE PERIOD WL BE COLD WITH A REINFORCING SHOT OF ARCTIC CHILL ARRIVING BEHIND FRIDAY'S CLIPPER...WITH THE USUAL LE SNOW SHOWERS. MODELS CONT TO INDICATE A WAVE OF LOW PRESSURE BLEEDING OFFSHORE SOUTH OF THE MASON DIXON LINE LATER SUNDAY AND MONDAY BUT MREFSF SUGGEST BEST MOISTURE AND LIFT WILL BE FOCUSED FURTHER SOUTH OVER VA AND THE CAROLINAS AT THAT TIME. AVIATION... BULK OF THE REGION WILL CONTINUE TO EXPERIENCE VFR CONDITIONS THROUGH THE NEXT 24 HOURS. HOWEVER...LAKE EFFECT WILL RESULT IN AREAS OF MVFR OVER THE ALLEGHENIES...WITH LOCALIZED IFR IN SNOW SHOWERS OVER THE NW MTNS AND LAUREL HIGHLANDS. && .CTP WATCHES/WARNINGS/ADVISORIES... PA...NONE. && $$ SHORT TERM...LAMBERT AVIATION... pa AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1015 AM CST WED MAR 9 2005 .DISCUSSION... CLOUDS OVER EASTERN CWA HAVE BEEN CLEARING THROUGH THE MORNING...AND EXPECT MUCH OF THE EAST TO SEE A FAIR AMOUNT OF SUNSHINE THROUGH THE EARLY AFTERNOON. WILL STILL SEE SOME INCREASE IN CLOUDS LATER TODAY AS THE BAND OF CLOUDS OVER CENTRAL SD MOVES SLOWLY EAST...BUT HAVE REMOVED ANY MENTION OF PRECIPITATION FROM THE LATE AFTERNOON...AS FORECAST SOUNDINGS FROM 12Z NAM AND RUC BOTH SHOW SUB-800MB LAYER REMAINING VERY DRY THROUGH 00Z. GOING FORECAST HIGHS 2-3 DEGREES HIGHER THAN FULL MIXING FROM 900MB 12Z MODELS WOULD INDICATE...BUT GIVEN DRY/BARE GROUND AND A BIT MORE SUNSHINE IN THE CENTRAL AND EASTERN CWA...WILL NOT MAKE ANY CHANGES AT THIS TIME. UPDATED GRIDS AND ZFP HAVE BEEN SENT. && .PREV DISCUSSION... 315 AM CST WED MAR 9 2005 NOT A LOT OF CHANGE FM YESTERDAY'S FCST WITH THE STRONG ERN CANADA UPPER VORTEX REMAINING FIRMLY IN PLACE THRU LATE IN THE WEEK...WITH PERIODIC IMPULSES MOVG DOWN THE NW FLOW INTO THIS AREA. ONE SHORTWV IS ABOUT THRU RIGHT NOW...WITH A FEW LINGERING FLURRIES IN FAR SE SD MOVG SEWD. FOR SKY COVER...WL LIKELY NOT BE A REAL PRISTINE DAY WITH PLENTY OF LOWER SC TO THE NORTH OF THE FA AND WAA CLOUDS RETURNING TO THE WRN FA BY LATE AFTN. THEREFORE PARTLY SUNNY MAY BE TOUGH TO SQUEEZE OUT ACROSS OUR WEST...BUT THERE WL PROBABLY BE SOME BREAKS ACRS THE ERN HALF. WITH THE STRONG WAA LIFT IN THE WEST LATE TODAY AND PLENTY OF MID LVL MSTR...DECIDED TO ADD A SLGT CHC OF -SHRA IN OUR WRN QUARTER. THIS STRONG WAA THEN PROCEEDS EWD ACRS THE REST OF THE FSD FA THRU MIDNIGHT. LOW LVL MSTR BEGINS TO BULK UP FINALLY ACRS SW MN AND DOWN TOWARD SPENCER AND STORM LAKE. THEREFORE KEPT CHC POPS GOING IN THOSE AREAS LATE THIS EVENING WITH ONLY SLGT CHCS ELSEWHERE WITH ONLY MID CLOUDS PREDOMINATING. PCPN TYPE IS PROBLEMATIC TONIGHT. AIR ALOFT AROUND H85 GOES ABV FREEZING FM W TO E AS THE EVENING PROGRESSES...SO IF THE SFC TEMPS DIP BLO FREEZING AT ANY GIVEN LOCATION ONE WOULD THINK A FREEZING SPRINKLE WOULD BE IN THE OFFING. DECIDED AGAINST THIS HOWEVER AS ALL LOCATIONS ARE LACKING A DEEP LOWER FLOW OF S OR SE WIND WHICH IS USUALLY PREFERRED FOR -FZRA. IN OTHER WORDS...THE LOWER LEVELS BLO H9 ARE DRY AND AM WORRIED ABOUT WET BULBING BACK DOWN TO -SN. MAIN STORY ON THU WILL BE THE WIND. MODELS STILL SHOWING 35 KTS COMMON AT 925MB WITH THE SNDGS MIXING ALL THE WAY UP TO H8. H85 WINDS ARE IN THE 40 TO 45 KT RANGE. WL DECIDE LATER ON WIND ADVY HEADLINE AS UPPER AGEOSTROPHIC FLOW IS ORIENTED FAIRLY PARALLEL WITH THE LOW LVL WIND FLOW...BUT CAA IS LACKING WITH PLENTY OF SC DRAINING DOWN FM THE NORTH. WINDY IN THE ZONES AND GRIDS WL HOLD IT FOR NOW. WITH THE STRONG MIXING WENT SLIGHTLY ABV MOST GUIDANCES. WINDS WL STAY UP THU NIGHT AND FRIDAY ALSO...BUT NOT QUITE TO THE DEGREE OF THU WITH SLIGHTLY LIGHTER FLOW ALOFT. PCPN CHCS THU AND THU NIGHT ARE SLIM WITH LACK OF MSTR BLO H9...NO MID LVL CLOUDS AND NOTHING IN THE WAY OF DYNAMICS. WENT A FAIR AMNT OF ABV ALL GUIDANCES ON FRIDAY DUE TO EXTREME MIXING ONCE AGAIN AND ANTICIPATING SOME BREAKING OF THE SC AS THE DAY PROGRESSES. STRONG WAA RETURNS FRI NIGHT WITH ANOTHER WK SFC LOW MOVG SE ACRS THE FAR WRN CWA AND WRN PLAINS. SO CONTINUED TO GO QUITE A BIT ABV THE NEW MEX GUIDANCE FOR LOWS SAT MRNG. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ HACKER sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 340 PM EST WED MAR 9 2005 .SHORT TERM (TONIGHT THROUGH THURSDAY)... GRADUALLY CLEARING SKIES TONIGHT AS THE LOW SPINS NORTHWARD INTO QUEBEC. A FEW EVENING FLURRIES IN THE MOUNTAINS...OTHERWISE NO SURPRISES. WINDS WILL STAY UP SOMEWHAT TONIGHT DESPITE CLEAR SKIES AS GRADIENT REMAINS FAIRLY ROBUST THROUGH THE EARLY MORNING HOURS...AND MIN TEMPS SHOULD REMAIN WARMER THAN EXPECTED WITH NEW DEEP SNOW COVER. FOR THURSDAY...CLOUDS FROM NEXT UPSTREAM SYSTEM BEGIN TO FILTER INTO THE REGION BY LATE AFTERNOON. && .LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...MORE INTERESTING WEATHER EXPECTED FOR THE NE. SIMILAR NOT ALL THAT DIFFERENT THIS WEEKEND...COMPARED TO YDA. HOWEVER...NEXT SYSTEM WILL BE SLOWER THAN THE LAST...AND NOT AS DEEP. EXPECT SNOW TO ARRIVE FRI AFTN FROM SW TO NE ACROSS THE FORECAST AREA. LOW SLOWS AND REDEVELOPS OFF THE MID ATLANTIC COASTLINE. STILL UNCERTAINTY AS TO HOW FAR OFFSHORE IT WILL DEVELOP. IN ANY CASE...NORLAN LOOKING TROUGH...UPPER LEVEL SUPPORT...MOISTURE AND INSTABILITY LINGERS BACK ACROSS INTERIOR NEW ENGLAND. WILL FORECAST LKLY POPS FRI AFTN THROUGH SAT. STILL UNCERTAIN WHERE THIS TROUGH SETS UP. ON LAST GASP POSSIBLE FOR WINTER POSSIBLE FOR LATER NEXT WEEK AS SURFACE LOW PULLS OUT OF THE GULF OF MEXICO WITH PLENTY OF MOISTURE. THEREAFTER...IT WILL BE HARD TO FIND COLD AIR ACROSS NORTH AMERICA FOR SNOW IN THE NE. && .AVIATION...SPOTTY MVFR VISIBILITIES THROUGH EARLY EVENING WITH SOME BLOWING SNOW...OTHERWISE VFR CONDITIONS EXPECTED. && .MARINE... SHORT TERM...GALE FORCE WINDS STILL GOING AT MISM1. RUC/LOCAL MESOSCALE MODEL SHOWING WINDS DROPPING BELOW GALE CRITERIA BY 00 UTC TONIGHT. WILL KEEP GALE GOING THROUGH 6 PM THEN RUN SMALL CRAFT FOR WINDS THEN SEAS OVERNIGHT. && .TIDES...TIDES WILL BE RUNNING ASTRONOMICALLY HIGH OVER THE NEXT FEW DAYS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...GALE WARNING FOR ANZ150 THROUGH 6 PM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR ANZ150 FROM 6 PM WEDNESDAY TO 8 AM THURSDAY. && $$ ST. JEAN/CANNON me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 352 PM EST WED MAR 9 2005 .DISCUSSION... MAIN FORECAST CONCERNS ARE CLIPPERS FOR THE NEXT 48 HOURS...THEN ABNORMAL COLD FOR THE EARLY PART OF THE WEEKEND. CURRENT WEATHER...19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS STILL SHOWED THE POSITIVE PNA/NEGATIVE NAO PATTERN WITH RIDGING OVER THE NORTH ATLANTIC AND WESTERN NORTH AMERICA WITH A TROUGH IN BETWEEN OVER THE EAST HALF OF CANADA AND THE U.S.. AN UPPER LEVEL LOW WAS SITUATED OVER NORTHERN MAINE WITH SHRTWVS ROTATING AROUND IT. ONE OF THEM IS CURRENTLY OVER EASTERN LAKE SUPERIOR...WHICH COMBINED WITH 850MB TEMPS AROUND -18C PER 12Z RAOBS AND LOW LEVEL CONVERGENCE FROM LAND BREEZES...AIDED IN PRODUCING SOME DECENT LAKE EFFECT SNOW OVER EASTERN ALGER AND NORTHERN SCHOOLCRAFT COUNTIES THIS MORNING. SNOWFALL RATES AT TIMES APPROACHED ONE INCH AN HOUR AT MELSTRAND BETWEEN 8 AND 10 AM. WESTERN LAKE SUPERIOR IS TOTALLY VOID OF ANY LAKE EFFECT DESPITE THE COLD 850MB TEMPS. TWO FACTORS ARE HINDERING THE LAKE EFFECT OUT THERE...ONE IS THE ICE WHICH COVERS NEARLY HALF OF IT AND THE OTHER IS THE DRY AIR. SURFACE RELATIVE HUMIDITIES ON THE NW SIDE OF THE LAKE ARE AROUND 30 PERCENT. SOME STRATOCUMULUS HAS BEEN TRYING TO MAKE IT SOUTH FROM NORTHERN ONTARIO...BUT IT HAS BEEN FALLING APART AS IT RUNS INTO THE DRY AIR MASS OVER THE WESTERN GREAT LAKES (SEE 12Z GRB AND INL SOUNDINGS). NEXT SHRTWV OF INTEREST...WHICH LOOKS REALLY STRONG ON WATER VAPOR FROM THE DARKENING...IS CURRENTLY OVER NORTHERN SASKATCHEWAN AND HEADING SE AS IT TOPPLES THE RIDGE IN THE WEST. SURFACE LOW ASSOCIATED WITH THE SHRTWV CURRENTLY OVER CENTRAL SASKATCHEWAN WHILE HIGH PRESSURE IS SITUATED OVER MN AND WESTERN WISCONSIN. BISMARCK RADAR AND SURFACE OBSERVATIONS HAVE SHOWN SOME -SN AHEAD OF IT...WITH MATCHES UP WELL WITH 800-700MB 2D FRONTOGENESIS FROM THE NAM. BEHIND THE CLIPPER...ANOTHER SHRTWV IS PRESENT OVER THE NORTHERN PART OF NINAVUT. TONIGHT AND THURSDAY...LAKE EFFECT IN THE EAST SHOULD GRADUALLY DIMINISH THIS EVENING AND SHIFT OFF TO THE EAST AS WINDS BECOMING WESTERLY AHEAD OF THE CLIPPER. MODELS HAVE COME INTO BETTER AGREEMENT WITH THE CLIPPER SHRTWV/SURFACE LOW SO WILL FOLLOW THE NAM FOR DETAILS. THE SHRTWV AND SURFACE LOW ARE PROGGED TO MOVE TO CENTRAL MN BY 12Z...THEN THE LOW DROPS SE TO THE CHICAGO AREA BY 00Z WITH THE SHRTWV OVER THE OHIO VALLEY. HIGH CLOUDS OVER WESTERN MINNESOTA AND NW ONTARIO SHOULD CONTINUE SPREADING EASTWARD AHEAD OF THE SHRTWV...ENTERING THE WESTERN U.P. THIS EVENING AND COVERING MUCH OF THE U.P. BY 06Z. LOWER LEVEL CLOUDS AND SNOW (LOOKING AT THE 850-500MB RH AND 800-700MB FRONTOGENESIS) WILL REACH THE WESTERN U.P. BETWEEN 09Z AND 12Z. SNOW MAY ACTUALLY COME DOWN PRETTY HEAVY AS THE BEST OMEGA INTERSECTS A NEAR 5000 FEET DEEP LAYER OF BEST SNOW GROWTH. TEMPERATURES A LITTLE TRICKY THIS EVENING UNTIL THE HIGH CLOUDS AND RETURN FLOW GET HERE. WILL FOLLOW A BLEND OF THE MAV/MET GUIDANCE. ON THURSDAY...EXPECT THE SNOW TO MOVE QUICKLY TO THE SOUTHEAST WITH THE CLIPPER. SINCE THE CLIPPER WILL BE GOING ACROSS SOUTHERN WISCONSIN...BEST AREA FOR SNOWFALL...WHICH MAY ONLY BE 1 TO 3 INCHES TOTAL GIVEN ITS SPEED...WILL BE ACROSS THE WISCONSIN BORDER COUNTIES. HAVE A CHANCE OF SNOW IN ACROSS THE REST OF THE CWA WITH THE LOWEST POPS IN THE EAST WHERE IT ULTIMATELY MAY NOT SNOW AT ALL DUE TO LOW LEVEL DRY AIR. COLD ADVECTION BEHIND THE CLIPPER MAY BE ENOUGH TO START OFF SOME LAKE EFFECT LATE THU FOR THE WESTERN U.P. (850MB TEMPS ON THE NAM DROP TO -14C)...HOWEVER THE DRY AIR ADVECTION IN THE LOW LEVELS IS QUITE IMPRESSIVE. WILL ONLY HAVE A 30 POP FOR SOME SCATTERED SNOW SHOWERS. HIGH TEMPS WARMER THAN TODAY FROM INITIAL WARM AIR ADVECTION FROM THE CLIPPER. MAV GUIDANCE LOOKS GOOD. THURSDAY NIGHT INTO FRIDAY...SHRTWV OVER NINAVUT DIVES DOWN TO LAKE WINNIPEG BY 12Z FRI AND THEN INTO SOUTHERN WISCONSIN BY 00Z SAT. SOME DIFFERENCES REGARDING THE SURFACE LOW PRESSURE THAT FOLLOWS THIS SHRTWV WITH THE GFS/UKMET/CANADIAN WEAKER THAN THE NAM. THE REASON IS THAT THE NAM DIGS THE SHRTWV MORE...PUTTING SOME TILT TO IT...THUS HAVING A DEEPER LOW. FOR NOW WILL FOLLOW A COMPROMISE. WILL KEEP CHANCE OF LAKE EFFECT SNOW SHOWERS THU NIGHT...HOWEVER IF THE NAM DOES PAN OUT...WINDS BACKING TO THE WEST COMBINED WITH ITS 850MB TEMPS OF -13C SHOULD PREVENT MUCH OF THE LAKE EFFECT UNTIL FRIDAY. PLACEMENT OF THE LAKE EFFECT MAY NEED TO BE ADJUSTED IN LATE FORECASTS. OTHERWISE...THU NIGHT SHOULD BE RELATIVELY DRY UNTIL THE SHRTWV ARRIVES AFTER MIDNIGHT. SOME -SN WILL ACCOMPANY IT DUE TO DPVA. HOWEVER GIVEN THAT IS COMING FROM NINAVUT...PROBABLY WILL NOT SEE MUCH IN THE WAY OF QPF. THE BIG THING WITH THE SHRTWV IS THE COLD ADVECTION. AFTER THE SHRTWV PASSES ON FRI...850MB TEMPS TUMBLE BELOW -20C. IN FACT...THE NAM HAS READINGS OF -26C OVER THE WESTERN LAKE AT 00Z SATURDAY. SHOULD SEE SOME DECENT LAKE EFFECT GET STARTED BEHIND THE SHRTWV...THOUGH THE AIR MASS IS PROGGED TO BE VERY DRY WITH DEWPOINT DEPRESSIONS OF 10C ABOVE 5000 FT. WILL UP POPS TO LIKELY BUT KEEP ACCUMULATIONS DOWN BECAUSE OF THE DRY AIR. FRIDAY NIGHT INTO SATURDAY...UPPER LOW PRESENTLY OVER MAINE ENDS UP ROTATING FULL CIRCLE...MOVING BACK TOWARDS JAMES BAY BY 12Z SAT AND NEAR LAKE SUPERIOR BY 00Z. ALL MODELS HAVE INDICATED THIS...WHICH MEANS THE COLD AIR THAT WAS PRESENT LATE FRIDAY IS NOT GOING ANYWHERE. BOTH PERIODS 850MB TEMPS SHOULD REMAIN BELOW -20C...RESULTING IN CONTINUED LAKE EFFECT SNOWS. HAVE RAISED POPS TO LIKELY FOR NW LAKE EFFECT SNOW BELTS BECAUSE OF THE GOOD AGREEMENT. FOR A THICKNESS REFERENCE...1000-500MB THICKNESSES FOLLOWING THE GFS ARE AROUND 502DAM...VERY LOW FOR THIS TIME OF YEAR. NAM IS PRETTY SIMILAR. WITH THIS COLD AIR...CLOUD COVER WILL NEED TO BE WATCHED. RIGHT NOW THE GFS AND NAM SHOW DEEP MOISTURE COMING IN WITH THE UPPER LOW...BUT FRIDAY NIGHT IS VERY UNCERTAIN AS THERE MAY BE A PERIOD OF CLEARING SKIES BEFORE IT GETS HERE. HAVE DROPPED LOWS TO A BLEND OF THE MET/MAV GUIDANCE...BUT THESE MAY NEED TO BE DROPPED EVEN MORE. HAVE ALSO DROPPED HIGHS FOR SATURDAY...BUT AGAIN THESE MAY HAVE TO BE DROPPED MORE. IN EITHER CASE...VERY COLD FOR THIS TIME OF YEAR. EXTENDED (SUN THROUGH WED)...MODELS REMAIN IN GOOD AGREEMENT ON THE UPPER LEVEL PATTERN THROUGH THE EXTENDED. SHRTWV COMING DOWN THE RIDGE OVER THE EASTERN PACIFIC SAT INTO MON WILL HELP TO CARVE OUT A TROUGH OVER THE WESTERN U.S.. THIS WILL RESULT IN UPPER LEVEL RIDGING TO DEVELOP ACROSS THE SOUTHEAST U.S. MON THROUGH WED. THE MAGNITUDE OF THIS RIDGING VARIES BETWEEN THE GFS AND ECMWF WITH THE ECMWF SHOWING MORE TOWARDS TUE EVENING. CLOSER TO HOME...THE UPPER LEVEL LOW THAT WAS SITUATED OVER NORTHERN ONTARIO ON SAT IS PROGGED TO MOVE TO NEW ENGLAND ON SUN NIGHT. ITS SOMEWHAT QUICK MOVEMENT IS DUE TO THE BLOCKING RIDGE OVER THE NORTH ATLANTIC SPLITTING APART WITH THE NORTHERN PART MOVING BACK TOWARDS NORTHERN QUEBEC. THE UPPER LEVEL LOW WILL NEED TO BE WATCHED THOUGH AS THE 06Z GFS SHOWS A SLOWER MOVEMENT. LAKE EFFECT SNOWS ALONG WITH ABNORMALLY COLD TEMPERATURES ARE EXPECTED TO CONTINUE SAT NIGHT THROUGH SUN NIGHT AS 850MB TEMPS ARE EXPECTED TO BE AROUND -20C. LAKE EFFECT WILL CONTINUE INTO MONDAY...BUT START TO DIMINISH DUE TO WARM ADVECTION. BY TUE THE UPPER LEVEL HIGH THAT SPLIT OFF OF THE NORTH ATLANTIC RIDGE WILL MERGE WITH THE RIDGE BUILDING ACROSS THE SOUTHEAST. AS A RESULT...SURFACE HIGH PRESSURE OVER THE PLAINS SHOULD BEGIN MOVING OVER THE GREAT LAKES. THIS IS EXPECTED TO OCCUR ON WED. WILL KEEP LAKE EFFECT SNOWS GOING ON TUE AND WED AS THE 06Z GFS STILL SHOW 850MB TEMPS COLD ENOUGH (AROUND -15C). && .MQT...WATCHES/WARNINGS/ADVISORIES... HEAVY FREEZING SPRAY WARNING IN EFFECT FOR EASTERN LAKE SUPERIOR && $$ AJ mi