WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 831 PM EST SAT NOV 20 2004 .DISCUSSION...WEAK UPPER DISTURBANCES MOVING OVER THE SERN STATES AND ADDITIONAL LIFT ALONG A QUASI-STATIONARY FRONTAL BOUNDARY OVER THE NORTHERN GULF COASTAL AREA CONTINUES TO PRODUCE A CANOPY OF CLOUDS FROM THE BIG BEND AREA NORTH AND WEST WITH AREAS OF LIGHT RAIN AND SHOWERS NOTED OVER THE PANHANDLE AND JUST NORTHWEST OF KTLH EARLY THIS EVENING. FURTHER SOUTH OVER THE FORECAST AREA WEAK SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC EXTENDING WEST ACROSS THE CENTRAL PENINSULA WAS PROVIDING MAINLY CLEAR SKIES...LIGHT SOUTHEASTERLY WINDS AND TEMPERATURES IN THE UPPER 60S TO ~70 DEGREES. .REST OF TONIGHT...MAINLY CLEAR SKIES...LIGHT TO CALM WINDS AND AN INCREASE IN DEW POINTS INTO THE LOWER 60 DEGREE RANGE WILL SET THE STAGE FOR SOME LATE NIGHT FOG DEVELOPMENT...SOME OF WHICH COULD BECOME LOCALLY DENSE IN SOME LOCATIONS TOWARD MORNING. ONGOING FORECAST HAS A GOOD HANDLE ON THIS...AND CURRENT TEMPERATURE TRENDS AND LATEST GUIDANCE SUPPORTS FORECASTED MIN TEMPERATURES OVERNIGHT... SO NO EVENING UPDATE EXPECTED. && .MARINE...C-MAN AND OFFSHORE BUOYS INDICATE EAST TO SOUTHEAST WINDS IN THE 5 TO 10 KNOT RANGE WITH SEAS OF 2 TO 3 FEET THIS EVENING. ONGOING FORECAST COVERS THIS WELL AND IS IN LINE WITH THE LATEST RUC/ MESO-ETA GUIDANCE...THEREFORE NO CHANGES EXPECTED IN THE 1030 PM UPDATE. .TBW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MCMICHAEL LONG TERM....RUDE fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 417 PM CST SAT NOV 20 2004 .SYNOPSIS...CLOUDS FINALLY BEGINNING TO BREAKUP OVER EAST CENTRAL IA THIS AFTERNOON. THESE WERE PART OF AN EXTENSIVE MVFR SC DECK THAT WAS WRAPPING AROUND LOW PRESSURE OVER LAKE SUPERIOR. RIDGE OF HIGH PRESSURE STILL WELL TO NW...FROM MT TO N CENTRAL NEB EARLY THIS AFTERNOON. AT UPPER LEVELS...LOW WAS OVER NV WITH SW FLOW AND EMBEDDED SHORTWAVES WELL OUT AHEAD OF IT INTO CENTRAL PLAINS. SEPARATE UPPER SHORTWAVE WAS PUSHING INTO WESTERN ONTARIO. && .SHORT TERM...(TONIGHT THROUGH SUNDAY)...SUBSIDENCE ASSOCIATED WITH HIGH PLAINS RIDGE EDGING EASTWARD WILL BE OFFSET BY EFFECTS OF ACTIVE UPPER LEVEL SW FLOW TO LIMIT TEMPERATURE PLUNGE OVERNIGHT. META AND RUC 925MB RH FIELDS INDICATE LOW CLOUDS THAT ARE BECOMING MORE DIURNAL IN APPEARANCE TO CONTINUE TO DISSIPATE AND SHIFT EAST OF AREA DURING EVENING. HOWEVER...MOSTLY THIN MID AND HIGH LEVEL CLOUDS SLIDING NORTHEAST AHEAD OF SHORTWAVE IN OK PANHANDLE TO OVERSPREAD CWA THIS EVENING JUST AS LOW CLOUDS CLEAR OUT. THIS WILL LIMIT RADIATIONAL COOLING...BUT WITH MUCH DRIER DEWPOINTS EDGING INTO AREA...SHOULD BE CONSIDERABLY COOLER THAN RECENT NIGHTS AND DID NOT STRAY FAR FROM MOS GUIDANCE WITH MID 20S TO LOWER 30S. ON SUNDAY...SURFACE HIGH PUSHES INTO IA SUNDAY BY AFTERNOON. TIME SECTIONS INDICATE PLENTY OF HIGH LEVEL RH AND WEAK LIFT TO KEEP CONSIDERABLE AMOUNT OF CLOUD COVER OVERHEAD. TRENDED HIGHS TOWARD LOW END OF GUIDANCE WITH RANGE FROM AROUND 40 NORTH TO MID 40S SOUTH...IN LINE WITH DIURNAL RISE BEING REALIZED IN SIMILAR AIRMASS OUT WEST TODAY. ..SHEETS.. && .LONGER TERM (SUNDAY NIGHT THROUGH NEXT SATURDAY)...PRIMARY FORECAST CONCERN IS MAJOR STORM IN THE TUESDAY/WEDNESDAY TIME FRAME. A 500MB CLOSED LOW LIFTS OUT OF SOUTHERN ARIZONA TUESDAY...DEEPENING RAPIDLY AS IT MOVES NORTHEAST. THE GFS BRINGS IT OVER EOK 12Z WEDNESDAY...WHICH IS CONSISTENT WITH PREVIOUS RUN. EXTRAPOLATING THE ETA OUT TO 12Z WEDNESDAY WOULD BRING THE LOW FURTHER NORTH... JUST NORTH OF DVN AND NOT QUITE AS DEEP. THE EUROPEAN AND UK BRING THE LOW A BIT NORTH OF THE GFS ALSO...AND WEAKER. AT THE SURFACE...THE GFS BRINGS THE SURFACE LOW TO BETWEEN UIN AND STL AROUND 06Z WEDNESDAY AND INTO THE NORTHEAST CORNER OF ILLINOIS BY 12Z. THE ETA IS FASTER...BRINGING THE SURFACE LOW THRU A SIMILAR TRACK 3 TO 6 HRS EARLIER. THE EUROPEAN BRINGS THE TRACK 100 MILES NORTH OF THE GFS...AND FASTER...AND THE UK 100 MILES SOUTH. EXPLOSIVE DEEPENING CONTINUES AS THE SYSTEM MOVES INTO THE WESTERN GREAT LAKES WEDNESDAY. WILL FAVOR THE GFS SOLUTION...EXCEPT SHADING A BIT NORTH AT BOTH 500MB AND THE SURFACE. THIS WILL BE CRITICAL WITH REGARD TO CHANGE OVER FROM RAIN TO SNOW. TUESDAY NIGHT THE 1000-500MB 540 MEAN THICKNESS MOVES RAPIDLY THRU THE FA BETWEEN APPROXIMATELY 08Z AND 14Z...WITH THE 1000-850MB 312 PARTIAL THICKNESS AND THE -2C 850MB ISOTHERM HAVING THE SAME TIMING. PRECIP WILL SPREAD ACROSS THE AREA TUESDAY...BECOMING LOCALLY HEAVY TUESDAY NIGHT...WITH A CHANGE OVER TO RAIN AND SNOW MIXED AND THEN SNOW NORTHWEST PORTION AFTER MIDNIGHT...AND TOWARDS DAWN IN THE QUAD CITIES...DIMINISHING TO FLURRIES WEDNESDAY MORNING...EXCEPT NORTH CENTRAL AND NORTHEAST WHERE LIGHT SNOW COULD CONTINUE INTO THE MORNING. AT THIS POINT...IT LOOKS LIKE ONE TO TWO INCHES IS POSSIBLE...MAINLY NORTH AND WEST OF A LINE FROM DUBUQUE TO CEDAR RAPIDS TO FREEPORT...ON GRASSY SURFACE WITH LITTLE OR NO ACCUMULATION ON ROADS DUE TO WARM GROUND TEMPERATURES...AND A DUSTING ON GRASSY SURFACES ELSEWHERE ACROSS THE FA. WINDS MAY TURN OUT TO BE THE BIGGEST IMPACT. THE GFS IS INDICATING 16MB OF GRADIENT ACROSS THE FA WEDNESDAY FROM 12Z TO 18Z. EVEN IF THIS GRADIENT BACKS OFF A BIT IN FUTURE RUNS...SUSTAINED 30 MPH WINDS...AND A WIND ADVISORY...SEEM TO BE A GOOD BET. THERE IS AN OUTSIDE CHANCE OF SEEING WINDS GUSTING INTO THE 40 TO 50 MPH RANGE. MODEL TIMING...TRACK...AND INTENSITY SHOULD START CONVERGING IN THE NEXT 24 HOURS...AND PROVIDE MORE FOCUS ON THE POTENTIAL FOR SNOW TUESDAY NIGHT INTO WEDNESDAY...AND HIGH WINDS WEDNESDAY. ONE WAY OR THE OTHER...IT WILL BE A BLUSTERY PERIOD...WITH WIND CHILLS COMING INTO THE PICTURE FOR THE FIRST TIME THIS SEASON...AS TEMPS FALL FROM THE 30S INTO THE UPPER 20S WEDNESDAY. GROUND TEMPS COULD HELP MINIMIZE THE IMPACT ON HOLIDAY TRAFFIC...BUT HIGH WINDS COULD PROVE TO BE A LIMITATION ON TRAVEL. ...REA... && DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ DLS/REA ia AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WICHITA KS 920 PM CST SAT NOV 20 2004 LIGHT RAIN OR SPRINKLES CONTINUE OVER SRN KS AND CEN KS ATTM, WITH RAIN HAVING TROUBLE STAYING TOGETHER AS IT MOVES INTO DRIER AIR FURTHER NE OF THE AREA. ISENTROPIC LIFT IN THE 295-300K LAYER IS STRONGEST OVER WRN SECTIONS OF THE AREA WHERE RAIN IS THE MOST EXTENSIVE. RUC/META MODELS KEEP THIS AREA OF LIFT GOING AT LEAST UNTIL 09Z/SUN SO WILL CONTINUE WITH HIGHEST POPS IN WRN SECTIONS OVERNIGHT AS LOWER LAYERS CONTINUE TO SATURATE. NEXT QUESTION IS POSSIBLE CHANGE OVER TO SNOW IN CENTRAL KS. MODEL SOUNDINGS STILL SUGGEST A CHANGEOVER STILL POSSIBLE AS ICE CRYSTALS HELP TO COOL THE LOW LAYERS CLOSE TO FREEZING. BEST CHANCE FOR THIS TO OCCUR APPEARS TO BE NW OF GREAT BEND TO SALINA LINE. SO WILL CONTINUE LIGHT SNOW OR A MIX OR RAIN/SNOW MENTION IN THIS AREA UNTIL 09Z UNTIL ICE CRYSTAL FORMATION ENDS AS DRIER AIR MOVES IN ALOFT. MAY SEE SNOW CHANCE CHANGE BACK OVER TO A DRIZZLE OR EVEN SOME FREEZING DRIZZLE ON ELEVATED SURFACES BY SUNRISE , BUT WILL NOT INCLUDE THIS MENTION AT THIS TIME. WILL ALSO TWEEK TEMPS UP A BIT, AS CLOUD COVER KEEP TEMPS FROM DROPPING AS MUCH AS FORECAST. KETCHAM ------------------------------------------------------------------ 300 PM CST SAT NOV 20 2004 .DISCUSSION... MAIN CHALLENGE IS DETERMINING THE PRECIPITATION TYPE, ESPECIALLY IN OUR NORTHERN COUNTIES FOR THE NEXT COUPLE OF DAYS. TONIGHT AND SUNDAY: THIS AFTERNOON UPPER LEVEL LOW WAS CENTERED NORTHERN UT, THEN A SHORTWAVE TROF EXTENDED SOUTHEASTWARD INTO WESTERN OK. THE SHORTWAVE TROF WAS MOVING TO THE NORTHEAST AND SCATTERED TO WIDESPREAD SHOWERS WERE OCCURRING THROUGH PARTS OF NORTHWEST OK, WESTERN KS, AND INTO SOUTH CENTRAL KS. AS THIS SHOT OF ENERGY MOVES NORTH THIS EVENING, THE ISENTROPIC LIFT IS ENHANCED MAINLY ACROSS THE WESTERN HALF OF THE FORECAST AREA. BECAUSE OF THE ENHANCE LIFT HAVE RAISED THE POPS IN THAT AREA TO THE LIKELY CATEGORY. BY MIDNIGHT LOOKS AS THOUGH THE LIFT SHOULD SUBSIDE, BUT WILL KEEP CHANCE OF PRECIPITATION GOING. THINK WE WILL HAVE A WINDOW WHERE THE PRECIPITATION TYPE COULD CHANGE OVER TO SNOW MAINLY ALONG AND NORTH OF A GREAT BEND TO LINCOLN LINE. SINCE THIS WINDOW OF TIME SHOULD BE ONLY ABOUT 2-5 HOURS, WOULD ANTICIPATE ANY ACCUMULATIONS TO STAY AN INCH OR LESS. THE PRECIPITATION TYPE CAN CHANGE VERY QUICKLY JUST WITH A FEW HUNDRED FEET OF DIFFERENCE IN THE DEPTH OF THE COLD AIR IN THE BOUNDARY LAYER. TO GIVE MYSELF A LITTLE BIT OF VARIANCE WILL MENTION THE CHANCE OF RAIN AND SNOW MIXED GENERALLY NORTH OF A LYONS TO SALINA LINE. ELSEWHERE RAIN. SUNDAY, ANOTHER CLOUDY DAY WITH EASTERLY TO NORTHEASTERLY FLOW AT THE SURFACE. LOWERED THE POPS TO THE CHANCE RANGE AND THE BEST CHANCE OF RAIN SHOULD BE IN OUR WESTERN AND SOUTHERN COUNTIES WHERE THE DYNAMICS SHOULD BE A LITTLE BETTER, DUE TO THE UPSLOPE IN WESTERN KANSAS AND THE BAROCLINIC ZONE IN OKLAHOMA. MONDAY: AM KEEPING CLOSE TO THE GFS MODEL THROUGH THIS TIME PERIOD. A BROAD BAROCLINIC ZONE ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY WILL STAY TO OUR SOUTH AS THE UPPER LEVEL LOW DEEPENS OVER THE SOUTHERN ROCKIES. OVER-RUNNING CLOUDINESS WITH CHANCES OF RAIN WILL CONTINUE AS LOW LEVEL MOISTURE REMAINS TRAPPED OVER US. TUESDAY-WEDNESDAY: THE UPPER LEVEL LOW IS EXPECTED TO MOVE OUT AND ACROSS THE SOUTHERN PLAINS ON TUESDAY. SOME OF THE COLDEST AIR WE HAVE SEEN THIS YEAR WILL ACCOMPANY THIS SYSTEM. WILL REMAIN WITH THE GFS SOLUTION ON THE TIMING ON THE MOVEMENT OF THE LOW. RAIN WILL BE A PRETTY GOOD BET ON TUESDAY, THE COLDER AIR WILL BE MOVING IN TUESDAY EVENING. MOST OF THE FORECAST AREA COULD SEE SOME SNOW TUESDAY NIGHT. ACCUMULATIONS IS THE BIG QUESTION THOUGH. IS POSSIBLE THAT SOME AREAS, MAINLY ALONG AND NORTH OF THE TURNPIKE COULD SEE SNOW AMOUNTS OF 2-4 INCHES. WILL NEED TO WATCH THIS AREA CLOSELY. THE PRECIPITATION SHOULD COME TO AN END EARLY WEDNESDAY WITH HIGHS ONLY IN THE UPPER 30S TO LOWER 40S. THURSDAY-SATURDAY: THANKSGIVING SHOULD BE A NICE DAY. UPPER LEVEL TROF EXPECTED TO BE OVER THE EASTERN U.S. WITH NORTHWEST FLOW THE DOMINANT FEATURE ACROSS THE CENTRAL U.S. THIS WILL RESULT IN A SURFACE LOW PRESSURE TROF ALONG THE LEE SLOPES OF THE ROCKIES AND WINDS OUT OF THE SOUTHWEST IN OUR AREA. FRIDAY, NEXT SHOT OF ENERGY IN THE NORTHWEST FLOW SHOULD MOVE THROUGH THE CENTRAL PLAINS AND AT THE SURFACE, WILL SEE A FRONT MOVE THROUGH. AT THIS POINT IN TIME AM KEEPING THE FRONTAL PASSAGE DRY BECAUSE THE GULF WILL BE CUT OFF, SO MOISTURE WILL BE LIMITED. THE FRONT IS EXPECTED TO MOVE THROUGH RATHER QUICKLY THEN HIGH PRESSURE OVER THE AREA ON SATURDAY. HIGHS FOR THE LATTER PART OF THE WEEK SHOULD BE IN THE 45 TO 50 DEGREE RANGE WITH LOWS IN THE MID TO UPPER 20S NORTH TO 30-35 DEGREE RANGE SOUTHEAST. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 36 44 37 48 / 60 50 30 40 HUTCHINSON 33 43 35 47 / 70 40 30 30 NEWTON 34 43 35 48 / 50 40 30 30 ELDORADO 36 45 37 49 / 50 40 30 40 WINFIELD-KWLD 38 45 38 49 / 60 50 40 40 RUSSELL 30 39 32 45 / 70 40 30 30 GREAT BEND 31 41 34 45 / 70 50 30 30 SALINA 33 43 34 46 / 50 40 30 30 MCPHERSON 33 43 34 47 / 60 40 30 30 COFFEYVILLE 39 49 39 52 / 40 40 40 40 CHANUTE 37 47 38 51 / 30 30 30 40 IOLA 37 47 37 50 / 30 30 30 40 && .ICT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 20/ELDER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA 1050 AM CST SAT NOV 20 2004 .UPDATED DISCUSSION...15Z RUC INITIALIZED A VORT MAX OVER SOUTHEAST LOUISIANA SOUTH OF LAKE PONTCHARTRAIN AND ANOTHER BETWEEN BROWNSVILLE AND HOUSTON. THE VORT MAX SOUTHWEST OF THE AREA IS EXPECTED TO MOVE ACROSS THE FORECAST AREA LATER THIS AFTERNOON AND EVENING. ERGO...SOME WILL SEE A SHORT BREAK IN PRECIP AND FORECASTED HIGH TEMPS ARE ON TRACK. WILL MAKE SOME COSMETIC CHANGES TO REMOVE MORNING FOG WORDING. OTHERWISE...EARLY MORNING PACKAGE IS ON TRACK FOR NOW. .PREV DISCUSSION...WET AND STORMY WEATHER HEADED FOR THE FORECAST AREA TODAY. DEEP AND BROAD UPPER TROUGH REMAINS FIRMLY IN PLACE ACROSS THE WESTERN STATES AS EMBEDDED DISTURBANCES ALONG THE BASE OF THE TROUGH BEGIN TO MOVE ACROSS THE REGION. CONVECTION IS ALREADY FIRING ACROSS EXTREME SOUTHEAST TEXAS LEADING INTO SOUTHWEST LOUISIANA AND EXPECT THIS ACTIVITY TO GRADUALLY WORK ITS WAY EASTWARD LATER TODAY AND THROUGH TONIGHT. SEVERE THREAT AT THIS POINT LOOKS MINIMAL MAINLY DUE TO A WEAK SHEARED ENVIRONMENT ALTHOUGH WOULD NOT OUT SOME FAIRLY STRONG GUSTY WINDS CLOSER TO THE BETTER ORGANIZED STORMS. THE PATTERN DOES NOT CHANGE MUCH FOR SUNDAY AS UPPER DISTURBANCES CONTINUE TO TRAVERSE ACROSS THE REGION WHILE A SURFACE BOUNDARY MEANDERS ALONG THE LOWER MISSISSIPPI VALLEY MAINLY NORTH OF THE CWA/PWA. MAY GET A BRIEF LULL IN THE CONVECTIVE ACTIVITY ON MONDAY AS AN UPPER LOW ASSOCIATED WITH THE UPPER TROUGH BEGINS TO PUSH TOWARD THE EAST. RAIN CHANCES CLIMB BACK UP INTO THE LIKELY CAT BY TUESDAY AS THE TROUGH SWINGS EASTWARD WHILE PUSHING A COLD FRONT TOWARD THE CENTRAL GULF COAST. MAY SEE A FEW STRONG STORMS DEVELOP ALONG AND AHEAD OF THIS BOUNDARY AS WELL. THE FRONT THEN LOOKS TO SWEEP THROUGH BY WEDNESDAY AS HIGH PRESSURE BEGINS TO BUILD ACROSS THE SOUTHERN PLAINS. AFTERWARDS...CLEARER SKIES ALONG WITH COOLER TEMPERATURES LOOK TO BE IN STORE FOR THE AREA THANKSGIVING DAY LEADING INTO FRIDAY. && PRELIM POINT TEMP/POPS... MCB 70 62 74 61 / 90 70 60 40 BTR 72 63 76 63 / 90 70 60 40 MSY 76 66 78 64 / 70 60 50 30 GPT 73 65 76 63 / 70 60 50 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. MS...NONE. SE LA AND MS COASTAL WATERS...NONE. && $$ 09 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 445 PM EST SAT NOV 20 2004 .DISCUSSION... CONCERNS ARE WEAK LK EFFECT TONIGHT AND MID WEEK STORM SYSTEM. WV LOOP AND RUC H5 HEIGHTS AND PV SHOW SHORTWAVE DIGGING INTO BASE OF W CONUS TROUGH OVR NEVADA. OTHER IMPORTANT SHORTWAVES OF NOTE OUT WEST IS SLIDING INTO GULF OF AK (THIS IS THE WAVE THAT COULD HELP DEVELOP SIG STORM OVR GREAT LAKES BY MID WEEK). SHORTWAVE THAT BROUGHT WIDESPREAD RAIN TO UPR MI LAST NIGHT IS CURRENTLY SHIFTING NE TOWARD QUEBEC. ASSOCIATED SFC TROUGH IS ALMOST THROUGH CWA...WITH A BREEZY WEST WIND DEVELOPING IN ITS WAKE. N BRANCH SHORTWAVE WITH A PUNCH OF CHILLY AIR IS SHIFTING INTO N MN. SHORT TERM (TONIGHT THROUGH MON NIGHT)...SHORTWAVE CURRENTLY TO NW WILL SWING ACROSS N PORTIONS OF UPR LAKES WITH AT LEAST A QUICK SHOT OF COLD AIR OVR LK SUPERIOR AND UPR MI. ETA HAS TRENDED TOWARD COLDER GFS SOLN OF LAST COUPLE DAYS WITH H85 TEMPS AROUND -9C OVR W LK SUPERIOR. MOISTURE IS PRETTY MEAGER ABOVE H9...SO ALTHOUGH WITH SUFFICIENT OVER WATER INSTABILITY (DELTA T/S 13-14C SOME SNOW SHOWERS WILL BE ABOUT...ACCUMS WILL BE MINOR (LESS THAN AN INCH). APPEARS BEST CHANCE OF SNOW SHOWERS WILL BE ON KEWEENAW WITH SOME WEAK LL CONVERGENCE AND OVER THE PORCUPINE AND HURON MTS. WINDS BACK LATE TONIGHT INTO SUN AM WITH ONLY A FEW FLURRIES BY AFTN OVR KEWEENAW. OTHERWISE...CLOUDS SHOULD BREAK FOR SOME CLEARING LATE TONIGHT INTO SUN NIGHT. TEMPS NEAR GUIDANCE LOOKED REASONABLE THROUGH THE PERIOD. QUIET WX SETS UP MON AND MON NIGHT AS WE AWAIT TO SEE WHAT OCCURS WITH SW UPR LOW. MID WEEK SYSTEM (TUE AND WED)...UNFORTUNATELY...ALTHOUGH NOT SURPRISING...NOTHING CLEAR CUT YET. OVERALL IDEA OF LOW PRES DEVELOPING OVR S PLAINS IN RESPONSE TO EVENTUAL EJECTION OF SHORGIVE SUFFICIENT OVER INSTABILITY FOR LK EFFECT SNOW SHOWERS. HAVE PUSHED POPS TO LIKELY ALONG LK SUPERIOR FOR THANKSGIVING INTO EARLY FRI. IF MID WEEK STORM MATERIALIZES...ENOUGH DEEP MOISTURE WOULD LIKELY BE PRESENT FOR SIGNIFICANT LAKE ENHANCEMENT THROUGH MUCH OF THU. EVEN WITHOUT THE STORM...SOME MILDER LK EFFECT WILL BE AROUND. BANKING ON LAKE INDUCED TROFFING TO LINGER OVR UPR LAKES (LONGER PERIOD OF NW FLOW THAN MODELS INDICATE) SO HAVE DELAYED BACKING OF WINDS AND RESULTANT DEPARTURE OF SNOW SHOWERS UNTIL FRI PM. HINT OF ANOTHER SHORTWAVE FOR FRI NIGHT-SAT WITH WEAK WARM AIR ADVECTION PROGGED. WENT WITH LOW CHANCE POPS FOR LGT SNOW TO TO START NEXT WEEKEND. IMAGINE EVEN WITHOUT ANY SYNOPTIC SYSTEM...AT LEAST SOME LK EFFECT SNOW IS POSSIBLE AS TEMPS REMAIN COLD ENOUGH AS WINDS VEER NW AGAIN. COORD WITH APX...THANKS. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1040 AM EDT SAT NOV 20 2004 .DISCUSSION...SFC LOW IN W UPPER WITH THE WARM FRONT RUNNING FROM ROUGHLY KISQ TO KCVX TO STURGEON POINT AS THE WIND SHIFTS FROM SE TO S AND THE WARM AIR FOLLOWS PRETTY CLOSELY. A GENEROUS AREA OF RAIN IS RUNNING ON THE LEAD EDGE OF THE SFC THETA-E RIDGE AND THE DPVA IN FRONT OF THE 500 MB VORT LOBE ROUGHLY OUT OVER CENTRAL LAKE MICHIGAN. BOTH THE ETA AND RUC HANDLE THIS PRETTY SIMILARLY WITH THE WARM AIR MOVING IN TO ALLOW TEMPERATURES TO GET TO AROUND 50 ACROSS MOST OF THE FORECAST AREA WITH THE LIKELY/CATEGORICAL POPS AND THE FOG/DRIZZLE COMBO GOING ON ACROSS THE REGION. ONCE THE 500 MB VORT LOBE MOVES THROUGH AND THE COLD FRONT PASSES THROUGH IN THE LATE AFTERNOON, DRIZZLE AND FOG WILL BE THE MAIN PROBLEMS AS THE MOISTURE AT AND ABOVE -10C STRIPS OFF. 850 DRYING WILL TAKE PLACE THIS EVENING. WEATHER, SKY, AND POP, GRIDS IN GOOD ORDER TODAY, TWEAKED TEMPERATURES DOWN A BIT FROM THE LOWER TO MID 50S TO UPPER 40S TO LOWER 50S RANGE. ZONES AND GRIDS PUBLISHED SHORTLY. LUTZ && .PREV DISCUSSION...ISSUED 330 AM EST SAT NOV 20 2004 SURFACE LOW CENTER IS MOVING THRU WISCONSIN ATTM. ASSOCIATED WARM FRONT EXTENDS SE FROM THE SURFACE LOW INTO SW LOWER MICHIGAN AND OHIO. LARGE AREA OF RAIN CONTINUES TO MOVE THRU NRN MICHIGAN AND NRN WISCONSIN NORTH OF THE WARM FRONT. AS EXPECTED... PRECIP HAS BEEN MAINLY LIGHT THROUGHOUT THIS EVENT. MAIN SHORT TERM FORECAST QUESTION IS HOW QUICKLY WILL PRECIP DIMINISH TO DRIZZLE AND THEN END COMPLETELY IN RESPONSE TO MID LEVEL DRYING ONCE THE LOW MOVES NORTH OF THE REGION. WX THEN REMAINS CALM INTO EARLY NEXT WEEK (THE CALM BEFORE THE STORM). ALL MODELS GENERALLY AGREE THAT MID LEVEL MOISTURE WILL BE STRIPPED AWAY BETWEEN 00Z AND 06Z SUNDAY...LEAVING NRN MICHIGAN WITH AMPLE LOW LEVEL MOISTURE TRAPPED BELOW A BUILDING SUBSIDENCE INVERSION AND WELL BELOW THE -10 C ISOTHERM. ALTHOUGH LOW LEVEL CAA WILL PROVIDE SUFFICIENTLY COLD AIR TO INDUCE LAKE ENHANCEMENT...LACK OF MOISTURE WILL PRECLUDE THE DEVELOPMENT OF LAKE ENHANCED PRECIP. GENERAL IDEA IS THAT ALL PRECIP SHOULD BE DONE BY 12Z SUNDAY AT THE LATEST. IN THE MEANTIME...TODAY...DEEP MOISTURE AND WEAK LIFT NORTH OF THE WARM FRONT WILL CONTINUE TO PRODUCE WIDESPREAD RAIN THRU THE MORNING FOR THE MAJORITY OF THE CWA. POPS WILL VERY GRADUALLY TAPER OFF FROM SW TO NE ACROSS THE REGION AS THE SURFACE LOW PUSHES NE INTO UPPER MICHIGAN BY AFTERNOON AND THEN INTO ONTARIO BY THIS EVENING. AREAS OF DRIZZLE AND FOG WILL ALSO CONTINUE...ESPECIALLY AS MID LEVELS BEGIN TO DRY DURING THE AFTERNOON. TEMPS WILL ONCE AGAIN REACH INTO THE UPPER 40S AND LOWER 50S THIS AFTERNOON BEFORE CAA BEHIND THE SURFACE LOW DROPS TEMPS BACK TO MORE SEASONAL LEVELS FOR THE REMAINDER OF THE WEEKEND. TONIGHT...MID LEVEL MOISTURE CONTINUES TO BE STRIPPED AWAY AS THE LOW PULLS FURTHER NE INTO CANADA. BY 06Z...LOW LEVEL MOISTURE HAS DROPPED WELL BELOW THE -10 C ISOTHERM. THUS...MEASURABLE PRECIP WILL BECOME UNLIKELY DESPITE INCREASINGLY FAVORABLE TEMP PROFILES FOR LAKE ENHANCEMENT AS 850 MB TEMPS DROP TO -5 C BY 12Z SUNDAY. DO THINK SOME AREAS OF DRIZZLE WILL CONTINUE INTO THE EVENING HOURS... BUT SHOULD END BY MIDNIGHT OR SO WHEN MOISTURE WILL BECOME SIMPLY TOO SHALLOW FOR PRECIP OF ANY KIND. DO EXPECT LOW CLOUDS WILL HANG ON THROUGHOUT THE NIGHT...SO WILL KEEP SKIES CLOUDY. SUNDAY THROUGH MONDAY...A COUPLE OF DRY AND PARTLY CLOUDY DAYS FOR THE START OF NEXT WEEK BEFORE WX BECOMES QUITE ACTIVE FOR THE REST OF THANKSGIVING WEEK. EXPECT HIGHS BOTH DAYS IN THE UPPER 30S AND LOWER 40S WITH LOWS IN THE UPPER 20S TO AROUND 30. NO CHANGES MADE TO THE REST OF THE FORECAST. && $$ .APX...WATCHES/WARNINGS/ADVISORIES...NONE. $$ mi AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 840 PM CST SAT NOV 20 2004 .UPDATE...ISSUING FLASH FLOOD WATCH FOR EASERN MOST HILL COUNTRY AND MOST OF SOUTH CENTRAL TEXAS...GENERALLY ALONG AND ALL POINTS EAST OF A LINE FROM BURNET TO BOERNE TO MEDINA AND PEARSALL. WILL LOWER SOME MIN TEMPS BASED ON CURRENT TRENDS AND OTHER MINOR CHANGES. STRONG CONVECTION IN SOUTHEAST IS FALLING APART. BUT GOOD VEERING WINDS AND UNSTABLE ATMOS WILL KEEP SHOWERS AND THUNDERSTORMS GOING. OVERRUNNING LIGHT SHOWERS PERSIST FOR THE MOST PART OVER THE EASTERN HILL COUNTRY AND AREAS OF SOUTH CENTRAL TEXAS ALONG AND EAST OF INTERSTATE 35. FOG HAS SETTLED IN OVER MOST SECTIONS. SURFACE PLOT AND RUC MODEL INDICATE THE SFC TROUGH WILL REMAIN SOMEWHERE IN THE VICINITY OF INTERSTATE 35 FOR THE NIGHT. WILL HOLD OFF ON DENSE FOG ADVISORY SINCE ONGOING SHOWERS AND FUTURE THUNDERSTORMS WILL IMPROVE VISIBILITIES. && .PREVIOUS DISCUSSION... HEAVY RAIN THREAT IS INCREASING AGAIN ACROSS SOUTH CENTRAL TEXAS. THE PRECIPITABLE WATER VALUES ARE ONCE AGAIN PUSHING NORTH OF 150 PERCENT OF NORMAL FOR MOST AREAS AS A STRONG UPPER LOW TO THE WEST INTERACTS WITH THIS MOISTURE. THE RAIN COOLED AIR IS KEEPING MOST RAIN AS SHOWERS WHICH SHOULD MINIMIZE THE FLOOD THREAT THROUGH LATE SUNDAY. PATCHY FOG WAS OCCURRING MOST AREAS TODAY AND WILL LIKELY CONTINUE THROUGH THE MORNING HOURS SUNDAY. FOR SUNDAY AFTERNOON, MODEL TRENDS ARE LEANING TOWARD WARMER AIR TO MIX INTO A DEEPER BOUNDARY LAYER AND WARM TEMPS INTO THE 70S FOR MANY AREAS. THIS MAY COME WITH ISOLATED SEVERE STORMS AGAIN AS WAS SEEN TODAY IN A FEW SPOTS. PRIMARY THREATS REMAIN HAIL AND TORNADOES WITH THE TORNADO THREAT HOLDING CLOSE TO THE COAST EARLY THIS EVENING AND DISAPPEARING FOR THE REST OF THE NIGHT. AFTERWARDS THE TORNADO THREAT MAY SHIFT DEEPER INTO THE FORECAST AREA DEPENDING ON THE EXTENT OF SOUTH WINDS AND NORTHWARD MIXING OF THE PSEUDO-FRONTAL INVERSION. WITH ABUNDANT MOISTURE CAUSING NUMEROUS CELLS IN COMPETITION WITH EACH OTHER, THE SEVERE/TORNADO THREAT TONIGHT AND SUNDAY STILL LOOKS TOO ISOLATED FOR MENTION IN THE FORECAST. THIS THREAT WILL REMAIN CONDITIONAL THROUGH TUESDAY WHEN THE UPPER STORM SYSTEM FINALLY DEPARTS. UNFORTUNATELY, THE CUMULATIVE RAIN AMOUNTS WILL MAKE FOR ANOTHER FLOOD CONCERN BY AS EARLY AS LATE SUNDAY AND CONTINUING THROUGH TUESDAY. BY WEDNESDAY AN HONEST TO GOODNESS COLD FRONT FINALLY WIPES AWAY ALL BUT THE GROUND MOISTURE AND BRINGS WITH IT A CHANCE OF FREEZING TEMPS BY THURSDAY MORNING. THE MODELS ARE SHOWING GOOD AGREEMENT AND CONSISTENCY ON KEEPING A POLAR JET DOMINATED PATTERN, SO THE CHANCE OF SUSTAINED DRY WEATHER APPEARS TO BE ON THE INCREASE FOR LATE IN THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 63 74 65 74 / 60 60 60 70 AUSTIN BERGSTROM INTL AIRPORT 63 75 65 74 / 60 60 60 70 DEL RIO INTL AIRPORT 63 75 63 73 / 20 40 50 60 SAN ANTONIO INTL AIRPORT 66 76 66 76 / 50 50 60 70 && .EWX WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH FOR FLASH FLOODING THROUGH 6 PM SUNDAY TXZ172-173-187-189>194-204>209-219>225. && $$ 06/02/PM tx AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 755 PM CST SAT NOV 20 2004 .UPDATE... WILL LOWER SOME MIN TEMPS BASED ON CURRENT TRENDS AND OTHER MINOR CHANGES. STRONG CONVECTION IN SOUTHEAST IS FALLING APART. BUT GOOD VEERING WINDS AND UNSTABLE ATMOS WILL KEEP SHOWERS AND THUNDERSTORMS GOING. OVERRUNNING LIGHT SHOWERS PERSIST FOR THE MOST PART OVER THE EASTERN HILL COUNTRY AND AREAS OF SOUTH CENTRAL TEXAS ALONG AND EAST OF INTERSTATE 35. FOG HAS SETTLED IN OVER MOST SECTIONS. SURFACE PLOT AND RUC MODEL INDICATE THE SFC TROUGH WILL REMAIN SOMEWHERE IN THE VICINITY OF INTERSTATE 35 FOR THE NIGHT. WILL HOLD OFF ON DENSE FOG ADVISORY SINCE ONGOING SHOWERS AND FUTURE THUNDERSTORMS WILL IMPROVE VISIBILITIES. && .PREVIOUS DISCUSSION... HEAVY RAIN THREAT IS INCREASING AGAIN ACROSS SOUTH CENTRAL TEXAS. THE PRECIPITABLE WATER VALUES ARE ONCE AGAIN PUSHING NORTH OF 150 PERCENT OF NORMAL FOR MOST AREAS AS A STRONG UPPER LOW TO THE WEST INTERACTS WITH THIS MOISTURE. THE RAIN COOLED AIR IS KEEPING MOST RAIN AS SHOWERS WHICH SHOULD MINIMIZE THE FLOOD THREAT THROUGH LATE SUNDAY. PATCHY FOG WAS OCCURRING MOST AREAS TODAY AND WILL LIKELY CONTINUE THROUGH THE MORNING HOURS SUNDAY. FOR SUNDAY AFTERNOON, MODEL TRENDS ARE LEANING TOWARD WARMER AIR TO MIX INTO A DEEPER BOUNDARY LAYER AND WARM TEMPS INTO THE 70S FOR MANY AREAS. THIS MAY COME WITH ISOLATED SEVERE STORMS AGAIN AS WAS SEEN TODAY IN A FEW SPOTS. PRIMARY THREATS REMAIN HAIL AND TORNADOES WITH THE TORNADO THREAT HOLDING CLOSE TO THE COAST EARLY THIS EVENING AND DISAPPEARING FOR THE REST OF THE NIGHT. AFTERWARDS THE TORNADO THREAT MAY SHIFT DEEPER INTO THE FORECAST AREA DEPENDING ON THE EXTENT OF SOUTH WINDS AND NORTHWARD MIXING OF THE PSEUDO-FRONTAL INVERSION. WITH ABUNDANT MOISTURE CAUSING NUMEROUS CELLS IN COMPETITION WITH EACH OTHER, THE SEVERE/TORNADO THREAT TONIGHT AND SUNDAY STILL LOOKS TOO ISOLATED FOR MENTION IN THE FORECAST. THIS THREAT WILL REMAIN CONDITIONAL THROUGH TUESDAY WHEN THE UPPER STORM SYSTEM FINALLY DEPARTS. UNFORTUNATELY, THE CUMULATIVE RAIN AMOUNTS WILL MAKE FOR ANOTHER FLOOD CONCERN BY AS EARLY AS LATE SUNDAY AND CONTINUING THROUGH TUESDAY. BY WEDNESDAY AN HONEST TO GOODNESS COLD FRONT FINALLY WIPES AWAY ALL BUT THE GROUND MOISTURE AND BRINGS WITH IT A CHANCE OF FREEZING TEMPS BY THURSDAY MORNING. THE MODELS ARE SHOWING GOOD AGREEMENT AND CONSISTENCY ON KEEPING A POLAR JET DOMINATED PATTERN, SO THE CHANCE OF SUSTAINED DRY WEATHER APPEARS TO BE ON THE INCREASE FOR LATE IN THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 63 74 65 74 / 60 60 60 70 AUSTIN BERGSTROM INTL AIRPORT 63 75 65 74 / 60 60 60 70 DEL RIO INTL AIRPORT 63 75 63 73 / 20 40 50 60 SAN ANTONIO INTL AIRPORT 66 76 66 76 / 50 50 60 70 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 06/02/PM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1005 AM CST SAT NOV 20 2004 .UPDATE...WEAK SFC BOUNDARY EXTENDS ALONG THE NEARSHORE WATERS OF THE UPPER TEXAS COAST AND EXTENDS WEST ACROSS THE COASTAL BEND AND RIO GRANDE PLAINS FROM NEAR PORT O'CONNOR TO JUST SOUTH OF COTULLA. THIS BOUNDARY AND STRONGER WINDS OFFSHORE/SOUTH WILL PROVIDE MOISTURE CONVERGENCE ACROSS MOST OF THE REGION MOST OF TODAY. THERE ARE A COUPLE S/WVS UPSTREAM ACROSS NRN MEXICO AND MODELS CONTINUE TO SHOW WEAK Q VECTOR CONVERGENCE THROUGH 6Z ACROSS CEN/S CEN TEXAS...HOWEVER THE DISTURBANCES ARE VERY WEAK AND DIFFICULT TO PICK OUT ON SATELLITE. MORNING SOUNDINGS SHOW MOIST/UNSTABLE ATMOSPHERE W/ NO CAP. THESE FACTORS CONTINUE TO POINT TO SCT CONVECTION FIRING THIS AFTN GIVEN SOME HEATING AND CAN'T RULE OUT AN ISOLATED STRONGER STORM GIVEN SOME WEAK SHEAR AND CAPES OVER 2000 J/KG IN AREAS THAT REACH 80 DEG F. LATEST RUC SHOWS FAVORED AREA FOR CONVECTION ALONG THE BOUNDARY ACROSS NRN SECTIONS AND INLAND SECTIONS OF THE COASTAL BEND WHERE BEST MOISTURE CONVERGENCE WILL EXIST THIS AFTN. THIS SEEMS REASONABLE AND HAVE TWEAKED POPS ON THE GRIDS TO REFLECT THIS THINKING SHOWING THE AXIS OF HIGHEST POPS (AND HIGHEST QPF) EXTENDING FROM NEAR ALI TO VCT W/ HIGHEST POPS STILL IN VCT AREA. BIGGEST CHANGE WAS TO LOWER POPS ALONG COAST AND OFFSHORE KEEPING BETTER RAIN CHC FOR SRN COASTAL BEND COUNTIES ALONG/WEST OF HIGHWAY 77. WILL UPDATE TEXT PRODUCTS ACCORDINGLY. IN ADDITION TO LOWERING POPS IN CWF...HAVE LOWERED WINDS TO BELOW SCEC IN OFFSHORE GROUP BASED ON OBS AND LATEST MODEL DATA. && .AVIATION...CIGS/VSBY WILL IMPROVE BUT EXPECT MVFR CONDITIONS TO PERSISTS FOR INLAND AREAS WHILE COASTAL AREAS LIKELY REMAIN VFR EXCEPT FOR NEAR ANY STORMS. APPEARS TIMING FOR PRECIP WILL BE BEST BETWEEN 18 AND 00Z AND LOOKS LIKE ANOTHER ROUND TO IFR STRATUS INLAND LATE TONIGHT WITH VSBYS BELOW ONE MILE TOWARD MORNING (ALI-VCT) AS HIGH LOW LEVEL MOISTURE CONTINUES AND WINDS DECOUPLE. && .SHORT TERM (TODAY THROUGH SUNDAY)...WEAK BOUNDARY EARLY THIS MORNING WAS LOCATED NEAR A LRD-VCT LINE. THIS ALONG WITH SOME WEAK UPPER LEVEL SUPPORT WILL PRODUCE SHOWERS AND THUNDERSTORMS TODAY...WITH BEST SHOT OVER THE NORTHEAST WHERE THE BOUNDARY WILL BE THE BEST FOCUS AND THETA-E ADVECTION WILL HELP. LEAST LIKELY SHOT FOR RAIN WILL BE OVER THE SOUTHWESTERN RIO GRANDE PLAINS WHERE THE MOISTURE FIELDS BECOME LESS IMPRESSIVE DURING THE DAY. GOOD DIRECTIONAL SHEAR EARLY THIS MORNING BECOMES A BIT MORE UNIDIRECTIONAL (BUT STILL SOME DIRECTIONAL SHEAR) LATER TODAY SO AT THIS TIME WILL NOT MENTION ANY SEVERE IN THE ZONE GROUPINGS OVER THE NORTHEAST WHERE THE SHEAR WILL BE BEST. WILL MENTION A SLIGHT POSSIBILITY IN THE WX OUTLOOK THIS MORNING. CONVECTION WILL WANE DURING THE EVENING HOURS LASTING LONGEST IN THE NORTHEAST WHERE THE BOUNDARY WILL BE PROXIMATE AND CONVERGENCE IS BEST. BOUNDARY REMAINS FOR SUNDAY BUT LACK OF UPPER SUPPORT AND LESS THETA-E ADVECTION WILL JUST GO WITH CHANCE POPS OVER THE EAST AND NORTH AND SLIGHT CHANCE OVER THE SOUTHWEST. TEMPERATURES A BIT TRICKY WHERE THE BOUNDARY IS AS IF THE BOUNDARY DOES NOT MOVE FAR ENOUGH NORTH AND/OR CONVECTION REMAINS FOR A GOOD PART OF THE DAY...TEMPS WILL NOT WARM AS MUCH. WILL BANK ON THE BOUNDARY MOVING NORTH OF THE AREA AND THUS WILL REMAIN GENERALLY ON THE WARM SIDE OF GUIDANCE FOR THE THREE PERIODS...ALTHOUGH SUNSHINE WILL BE LIMITED AT LEAST WITH HIGH CLOUDS AROUND BUT WILL HAVE WAA IN THE BOUNDARY LAYER. && .AVIATION...CIGS AND VSBYS HAVING A HARD TIME GOING DOWN THIS MORNING BUT DO EXPECT MVFR OVER THE EAST AND LIFR FOR CIGS OVER THE WEST (LRD AND ALI) THIS MORNING. WILL HAVE WEAK NORTHEAST WINDS PROXIMATE TO THE BOUNDARY THIS MORNING BUT EXPECT GENERALLY SOUTHEAST WINDS DURING THE DAY AS WINDS MIX OUT AND BOUNDARY MOVES NORTH. WILL NEED TO MENTION RAINFALL ALL BUT THE LRD TAFS WITH MOST PESSIMISTIC TAFS OVER THE VCT AREA. AT LEAST MVFR CONDITIONS WILL DEVELOP AGAIN OVERNIGHT AS WINDS SUBSIDE AND BOUNDARY LAYER REMAINS MOIST. MOST OF THE FOG ISSUES SHOULD BE LIGHT GIVEN LIMITED RADIATIONAL COOLING DUE TO CLOUDS. && .MARINE...WINDS NEAR OUR COASTAL ZONES NEAR SCA CONDITIONS OVER THE OFFSHORE WATERS BUT DO EXPECT WINDS TO DECREASE A BIT TONIGHT AS THE JET WEAKENS AND MOVES INLAND. WILL GO WITH SCEC FOR THE OFFSHORE WATERS WITH NO FLAGS FOR THE OTHER AREAS. WINDS WILL REMAIN BELOW SCEC TONIGHT AND SUNDAY. ONLY OTHER CONCERN ARE HIGHER WINDS AND SEAS NEAR THUNDER. && .LONG-TERM (SUNDAY NIGHT THROUGH FRIDAY)...RAIN CHANCES WILL CONTINUE THROUGH THE FIRST PART OF NEXT WEEK BEFORE A COLD FRONT MOVES THROUGH AREA AND BRINGS RAIN CHANCES TO AN END TUESDAY NIGHT. GUIDANCE CONTINUES TO CONVERGE ON SOUTH TEXAS FROPA DURING THE DAY ON TUESDAY...ALTHOUGH THERE ARE SOME SLIGHT VARIATIONS IN TIMING DEPENDING ON THE MODEL OF CHOICE. IN THE MEANTIME...EXPECT ISOLATED TO SCATTERED TSRA...MAINLY ACROSS THE NORTHERN COUNTIES AS WARM FRONT SLOWLY LIFTS TO THE NORTH. WILL SEE MORE FAVORABLE UPPER-LEVEL DYNAMICS ON MONDAY BUT MOST OF THE ENERGY WILL REMAIN WELL TO THE NORTH OF OUR CWA. IF AN MCS DOES DEVELOP ACROSS THE HILL COUNTRY...IT MAY CLIP THE NORTHEAST COUNTIES. GFS SHOWS CORFIDI VECTORS FROM ABOUT 300 DEGREES AT 20 KNOTS SO SOME SOUTHWARD PROPAGATION IS POSSIBLE. WILL SHOW WINDS BEGIN TO VEER TO THE SOUTHWEST EARLY TUESDAY AS SURFACE TROF MOVES ACROSS THE AREA WITH THE COLD FRONT LAGGING BEHIND A BIT. SHOULD STILL SEE TEMPS 5 OR SO DEGREES ABOVE NORMAL ON TUESDAY BEFORE THE COOLER AIR MOVES IN. PRECIP SHOULD END FAIRLY QUICKLY FROM WEST TO EAST ON TUESDAY AS DRIER AIR WRAPS AROUND THE SYSTEM. WILL NOTE THAT THE NOGAPS IS ABOUT 12 HOURS SLOWER WITH THE FROPA THAN MOST OF THE OTHER GUIDANCE SO WILL GO WITH THE FASTER SOLUTIONS. WILL SHOW DRY FORECAST FROM TUESDAY NIGHT THROUGH THE REMAINDER OF THE PERIOD. OVERNIGHT TEMPS SHOULD BE QUITE COOL ON THURSDAY MORNING WITH HIGH PRESSURE CENTERED OVER THE AREA. MEX GUIDANCE IS MUCH COOLER TONIGHT AND WILL TREND DOWN TOWARD THESE NUMBERS WHICH MAY BE CLOSE TO 40 ACROSS THE NORTHERN COUNTIES. WOULD NOT BE SURPRISED TO SEE A FEW UPPER 30S READINGS OVER THE RIO GRANDE PLAINS. THE SURFACE HIGH WILL MOVE OVER TO THE SOUTHEASTERN CONUS ON FRIDAY ALLOWING ONSHORE FLOW BACK TO SOUTH TEXAS. TEMPS AND DEWPOINTS WILL SLOWLY WARM BACK TO NEAR/SLIGHTLY ABOVE NORMAL. GFS SHOWS ANOTHER WEAK FRONT OVER THE WEEKEND...AND WILL SHOW WIND SHIFT. MOST OF THE UPPER-LEVEL DYNAMICS REMAIN WELL TO THE NORTH FRONT MAY HAVE A HARD TIME MAKING IT THIS FAR SOUTH. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 81 71 83 66 81 / 40 20 30 20 20 VICTORIA 77 67 80 64 76 / 70 50 50 40 40 LAREDO 79 67 82 62 82 / 20 10 20 20 30 ALICE 82 69 84 64 81 / 50 20 30 20 20 ROCKPORT 79 71 80 68 79 / 40 50 50 30 30 COTULLA 78 65 82 62 76 / 30 20 30 30 40 && .CRP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ MJG...UPDATE 86/GW...SHORT-TERM 94/MJ...LONG-TERM tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BURLINGTON VT 1005 AM EST SAT NOV 20 2004 .UPDATED DISCUSSION... EVERYTHING IS ON SCHEDULE ACRS FA. CLDS HAVE ALRDY ADVANCED INTO CHMPL VLY...THUS HAVE UPDATED CLD CVR FOR NY ZONES. SE GRADIENT INCRSG ACRS FA TO ALLOW SOME FUNNELING ACRS ST LWRNV VLY AND HAVE UPPED WNDS THERE. OTHERWISE...ALL IS WELL AND WL FOCUS ON TNGTS EVENT AND THE UPCOMING HOLIDAY FCST IN THIS AFTNS DISC. && .PREVIOUS DISCUSSION... .SYNOPSIS... HI PRESS TO BUILD ACRS THE FA TODAY...AS A STORM SYS MOVES UP ACRS THE GREAT LKS REGION. THIS STORM TO MOVE ACRS SRN CANADA TONITE. A CF TO MOVE ACRS THE FA ON SUN/SUN NITE. MORE HI PRESS TO BUILD IN ACRS THE FA ON MON. S/W TO MOVE ACRS THE FA TONITE. UPR TROF TO MOVE ACRS THE FA ON MON. .SHORT TERM (THROUGH MON)... 00-03Z 13KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE M30S-M40S TODAY WITH EASTERLY SFC WINDS DEVELOPING AT 5-10 KTS. T1MAX TEMPS ARE IN THE L40S-L50S TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA. LOW-LVL MSTR TO INCREASE ACRS THE WRN TIER ZONES THIS AFTERNOON. PW VALUES TO INCREASE ACRS THE FA FROM AROUND 0.2" (AS INDICATED BY REGIONAL GPS IPW SITES ATTM) TO JUST LESS THAN AN INCH TODAY. RUC SHOWS SOME -RA BREAKING OUT ACRS NY STATE BY LATER TODAY...WITH SKIES BECOMING CLDY OTRW. LOTS OF CLDS ACRS THE FA NOTED IN IR SAT PIX ATTM. LEADING EDGE OF THE PCPN ON BUFCAN/88D MOSAIC HAVING HARD TIME REACHING THE GROUND ACRS NY STATE ATTM. H85 WAA TO TAKE PLACE ACRS THE FA TODAY AND TONITE...THEN CAA FOR SUN THRU MUCH OF MON. H85 TEMPS TO GO NEGATIVE ACRS THE FA BY AROUND 06Z MON. H925 WET-BULB TEMPS TO NOT GO TOTALLY POSITIVE ACRS THE ENTIRE FA UNTIL 06-12Z SUN. LATEST ETA BUFR DATA SHOWS SOME SITES IN THE NRN ADIRONDACKS LATER TODAY AND IN ERN AND CENTRAL VT TONITE WITH TEMPS/WET-BULB TEMPS HUGGING THE ZERO LINE...SO HAVE ADDED THE CHC FOR A MIX WITH PL/SN IN THESE LOCATIONS FOR LATER TODAY AND TONITE. GOOD LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA TODAY AND TONITE. LOW-LVL MSTR TO AFFECT THE FA TONITE AND ON SUN...WITH JUST SOME LINGERING LOW-LVL MSTR ACRS THE FA ON SUN NITE AND MON. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA ON MON AFTERNOON. MID-LVL LAPSE RATES TO BE HI ACRS THE FA ON SUN AFTERNOON. MID-LVL MSTR TO INCREASE ACRS THE FA FOR TODAY...TONITE AND EARLY ON SUN. JUST SOME MID-LVL MSTR ACRS THE FA ON MON. PW VALUES ACRS THE FA LOOK TO BE 0.6-0.8" TONITE AND 0.3-0.5" ON SUN/SUN NITE. WILL HANG ONTO SOME PCPN POSSIBLE ACRS THE NY ZONES AND FAR WRN VT BY LATER TODAY. PCPN TO BREAK OUT ALL ACRS THE ENTIRE FA TONITE AND MAYBE LINGER INTO AT LEAST SUN (IF NOT SUN NITE AS WELL...WHEN A CHANGE OVER TO SHSN MAY OCCUR IN THE HIR TRRN). HAVE GONE WITH LIKELY POPS ACRS THE FA TONITE AND 20-30% POPS ON SUN/SUN NITE. BEST CHC FOR ANY SOLID PCPN TONITE LOOKS TO BE UP ACRS THE NE KINGDOM. MON LOOKS TO BE DRY ACRS THE FA BUT NOT TOO MUCH SUNSHINE EXPECTED WITH SOME LINGERING MSTR AROUND AND AN UPR TROF PASSAGE THEN. T1MIN TEMPS ARE IN THE 30S TONITE AND T1MAX TEMPS ARE IN THE 50S ON SUN...BUT WILL GO BLO THESE VALUES ON SUN WITH PLENTY OF CLDS/CAA AROUND AND SOME POSSIBLE PCPN. .LONG TERM (MON NITE ONWARD)... NO CHANGES TO THE GOING FCST FOR NOW. WRK ZONES AND PRELIM ISC GRIDS AVAILABLE. ALL FINAL PRODUCTS BY AROUND 4 AM. MURRAY .AVIATION... VFR CONDITIONS EXPECTED THRU MCH OF THE DAY WITH INCRG MID/HI CLDS AND CIGS GRDLY LOWERING DURING THE DAY. SHOWERS AND MVFR CONDITIONS WL SPREAD EWD ACRS NNY AFT 20Z AND ACRS VT AFT 00Z. WDSPRD MVFR TNGT IN AREAS OF RAIN. LGT WINDS THRU THE PD. KJC .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 440 AM EST SUN NOV 21 2004 .DISCUSSION... MAIN FCST CONCERNS TURN FROM LINGERING WEAK AND TEMPS TO LES POTENTIAL THIS MORNING AND MID WEEK STORM SYSTEM. WV IMAGERY AND RUC ANALYSIS INDICATED NRN STREAM SHRTWV FROM N CNTRL ONTARIO THROUGH LK SUPERIOR AND ANOTHER WEAKER SHRTWV UPSTREAM OVER SASK. SRN STREAM CLOSED LOW...WHICH WILL IMPACT WEATHER INTO THE GRT LAKES BY MIDWEEK...LURKED OVER SRN NV. STRONG QDIV/SUBSIDENCE IN THE WAKE OF THE ONTARIO SHRTWV HAS BROUGHT CLEARING SKIES OVER NE MN INTO WRN LK SUPERIOR. DESPITE H8 TEMPS TO NEAR -8C (GIVING LK-H8 DELTA/T TO AROUND 14C) IR LOOP SHOWED ONLY WEAK LAKE EFFECT CLOUD BANDS OVER WRN LAKE SUPERIOR WHILE RADAR/SFC OBS SHOWED ONLY SCT-BKN SC OVER THE WEST WITH NO PCPN. MDLS HAVE UNDERPLAYED EFFECTS OF TIGHT GRADIENT OVER THE REGION WHICH SUPPORTED STIFF WEST WINDS TO AROUND 35 MPH AT KCMX WHERE LCL TERRAIN EFFECTS ENHANCE EFFECTS OF WRLY FLOW. CMAN OBS OVER THE LAKE ALSO SHOWED WINDS GUSTING AOA 35KT OVERT N AND E PORTION OF THE LAKE. TODAY...MENTION OF A FEW FLURRIES RETAINED FOR THE NRN KEWEENAW WHERE BEST LOW LVL CONV AND LONG WSW FETCH COULD STILL SUPPORT SOME --SHSN. GRADUALLY BACKING WINDS WILL BE MAIN EFFECT OF MOISTURE STARVED AND INCREASINGLY SHEARED SASK SHRTWV MOVING TOWARD THE AREA TODAY INTO THIS EVENING. ASSOCIATED MID CLOUDS SHOULD REMAIN NORTH OF THE AREA. SO...EXPECT DECENT AMOUNT OF SUNSHINE...ESPECIALLY ACRS THE SOUTH HALF OF THE CWA. EVEN WITH INTRUSION OF COLD AIR...TEMPS SHOULD RECOVER TO AROUND 40F...IN LINE WITH GUIDANCE. TONIGHT INTO MONDAY...EVEN THOUGH GRADIENT REMAINS STRONG ENOUGH TO KEEP WSW WINDS GOING TONIGHT...EXPECT ENOUGH DECOUPLING INLAND FOR RADIATIONAL COOLING TO PUSH TEMPS DOWN TO NEAR 20 WHILE READING REMAIN IN THE UPPER 20S TO AROUND 30 CLOSER TO THE LAKES AND IN DOWNSLOPE LOCATIONS. TUE...WITH LACK OF SIGNIFICANT MOISTURE INFLOW...WEAK QG FORCING / FRONTOGENESIS AHEAD OF NRN STREAM MID LVL TROF LOOKS MARGINAL TO SUPPORT ANY PCPN. FOR NOW...CHANCE POPS WERE RETAINED GIVEN GFS GUIDANCE AND RELATIVELY CONSISTENT GFS DEPICTION OF LGT PCPN. GFS LOW LVL THICKNESS STILL SUPPORTS RA/SN OVER THE WEST AND MAINLY RAIN SE. TUE NIGHT INTO WED...THE GFS/UKMET/ECMWF HAVE COME INTO BETTER AGREEMENT WITH THE FATE OF THE SRN STREAM SHRTWV AND RESULTING SFC LOW TRACK (CONSENSUS...FROM THE OK TO SE LWR MI AND GEORGIAN BAY). WITH MORE PROMINENT NRN STREAM HGT FALLS DEPICTED INTO NRN ONTARIO AND QUEBEC FLATTER MID LVL PATTERN SEEMED TO FAVOR A BIT LESS PHASING AND TRACK FARTHER TO THE SE. HOWEVER...A SIGNIFICANT NUMBER OF GFS ENSEMBLES AND SOME CANADIAN ENSEMBLE MEMBERS STILL SUGGEST POSSIBILITY OF A STRONGER LOW WITH MORE WRLY TRACK DEPICTED BY GFS 00Z-12Z/20 GFS RUNS. SO...CONSIDERABLE UNCERTAINTY REMAINS. WHILE MDLS SOLUTIONS WOULD BE MARGINAL FOR SYNOPTIC PCPN INTO THE WEST HLF OF UPR MI...H8 TEMPS AROUND -11C AND DEVELOPING CYCLONIC NRLY FLOW WITH RELATIVELY DEEP COLD AIR WOULD STILL FAVOR AT LEAST LIKELY POPS FOR LES OVER THE NORTH HALF WITH POSSIBILITY OF LIGHT TO MODERATE ACCUMULATIONS. FOR NOW MADE FEW CHANGES...EXECPT TO REDUCE POPS OVER THE S AND PUSH RAIN CHANCES WED FARTHER EAST. IF CONSENSUS LOW TRACK MATERIALIZES...PCPN WILL REMAIN ALL SNOW. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 104 AM CST SUN NOV 21 2004 .UPDATE... ADDED DENSE FOG ADVISORY TO MIX FOR REST OF EARLY MORNING TIL 10 AM. ALSO LOWERED POPS THRU MID MORNING WEST OF IH35. HAVE && .PREV DISCUSSION... MOST OF SOUTH CENTRAL TEXAS...GENERALLY ALONG AND ALL POINTS EAST OF A LINE FROM BURNET TO BOERNE TO MEDINA AND PEARSALL. WILL LOWER SOME MIN TEMPS BASED ON CURRENT TRENDS AND OTHER MINOR CHANGES. STRONG CONVECTION IN SOUTHEAST IS FALLING APART. BUT GOOD VEERING WINDS AND UNSTABLE ATMOS WILL KEEP SHOWERS AND THUNDERSTORMS GOING. OVERRUNNING LIGHT SHOWERS PERSIST FOR THE MOST PART OVER THE EASTERN HILL COUNTRY AND AREAS OF SOUTH CENTRAL TEXAS ALONG AND EAST OF INTERSTATE 35. FOG HAS SETTLED IN OVER MOST SECTIONS. SURFACE PLOT AND RUC MODEL INDICATE THE SFC TROUGH WILL REMAIN SOMEWHERE IN THE VICINITY OF INTERSTATE 35 FOR THE NIGHT. WILL HOLD OFF ON DENSE FOG ADVISORY SINCE ONGOING SHOWERS AND FUTURE THUNDERSTORMS WILL IMPROVE VISIBILITIES. HEAVY RAIN THREAT IS INCREASING AGAIN ACROSS SOUTH CENTRAL TEXAS. THE PRECIPITABLE WATER VALUES ARE ONCE AGAIN PUSHING NORTH OF 150 PERCENT OF NORMAL FOR MOST AREAS AS A STRONG UPPER LOW TO THE WEST INTERACTS WITH THIS MOISTURE. THE RAIN COOLED AIR IS KEEPING MOST RAIN AS SHOWERS WHICH SHOULD MINIMIZE THE FLOOD THREAT THROUGH LATE SUNDAY. PATCHY FOG WAS OCCURRING MOST AREAS TODAY AND WILL LIKELY CONTINUE THROUGH THE MORNING HOURS SUNDAY. FOR SUNDAY AFTERNOON, MODEL TRENDS ARE LEANING TOWARD WARMER AIR TO MIX INTO A DEEPER BOUNDARY LAYER AND WARM TEMPS INTO THE 70S FOR MANY AREAS. THIS MAY COME WITH ISOLATED SEVERE STORMS AGAIN AS WAS SEEN TODAY IN A FEW SPOTS. PRIMARY THREATS REMAIN HAIL AND TORNADOES WITH THE TORNADO THREAT HOLDING CLOSE TO THE COAST EARLY THIS EVENING AND DISAPPEARING FOR THE REST OF THE NIGHT. AFTERWARDS THE TORNADO THREAT MAY SHIFT DEEPER INTO THE FORECAST AREA DEPENDING ON THE EXTENT OF SOUTH WINDS AND NORTHWARD MIXING OF THE PSEUDO-FRONTAL INVERSION. WITH ABUNDANT MOISTURE CAUSING NUMEROUS CELLS IN COMPETITION WITH EACH OTHER, THE SEVERE/TORNADO THREAT TONIGHT AND SUNDAY STILL LOOKS TOO ISOLATED FOR MENTION IN THE FORECAST. THIS THREAT WILL REMAIN CONDITIONAL THROUGH TUESDAY WHEN THE UPPER STORM SYSTEM FINALLY DEPARTS. UNFORTUNATELY, THE CUMULATIVE RAIN AMOUNTS WILL MAKE FOR ANOTHER FLOOD CONCERN BY AS EARLY AS LATE SUNDAY AND CONTINUING THROUGH TUESDAY. BY WEDNESDAY AN HONEST TO GOODNESS COLD FRONT FINALLY WIPES AWAY ALL BUT THE GROUND MOISTURE AND BRINGS WITH IT A CHANCE OF FREEZING TEMPS BY THURSDAY MORNING. THE MODELS ARE SHOWING GOOD AGREEMENT AND CONSISTENCY ON KEEPING A POLAR JET DOMINATED PATTERN, SO THE CHANCE OF SUSTAINED DRY WEATHER APPEARS TO BE ON THE INCREASE FOR LATE IN THE WEEK. && .EWX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVY ALL ZONES THRU 10 AM FLOOD WATCH FOR FLASH FLOODING THRU 6PM ALONG/EAST OF IH35 TXZ172-173-187-189>194-204>209-219>225. && $$ 09/13 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 319 AM EST SUN NOV 21 2004 .SYNOPSIS... FRONTAL SYS TO MOVE ACRS THE FA FROM THE WEST TODAY AND EARLY TONITE. HI PRESS TO BUILD INTO THE FA FROM THE WEST LATER TONITE THRU MON NITE...THEN MOVE OFF TO THE EAST OF THE FA ON TUE. UPR TROF TO MOVE ACRS THE FA ON MON. S/W TO MOVE TO THE NORTH OF THE FA ON TUE. .SHORT TERM (THROUGH TUE)... 00-03Z 13KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE M30S-M40S TODAY WITH SOUTHERLY SFC WINDS FOR MUCH OF THE DAY AT 5-10 KTS. T1MAX TEMPS ARE IN THE 50S TODAY AND LOOK WAY TOO WARM BASED ON EXPECTED CLD COVER AND PCPN CHCS. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA. LOW-LVL MSTR TO CONT AFFECT THE FA FOR MUCH OF TODAY. PW VALUES ACRS THE FA TO BE 0.3-0.8" TODAY. RUC SHOWS CLDY SKIES AND SCT SHRA ACRS THE FA TODAY. BUFCAN/88D MOSAIC SHOWS JUST SOME SCT PCPN ACRS THE FA ATTM. NO BINOVC NOTED IN REGIONAL IR SAT PIX ATTM. EARLIER...AT LEAST A MIX WITH PL/SN WAS OCCURRING ACRS PARTS OF NE/NC VT AND ALONG THE SPINE OF THE GREEN MTNS IN SRN VT...WITH AT LEAST AN INCH OF MEASURABLE SN AT SUTTON VT. H85 CAA TO TAKE PLACE ACRS THE FA TODAY THRU MUCH OF MON...THEN WAA TO DEVELOP ACRS THE FA ON MON NITE/TUE. H85 TEMPS TO GO NEGATIVE ACRS THE FA BY 00-06Z TONITE. H925 WET-BULB TEMPS TO GO NEGATIVE ACRS THE NRN TIER ZONES BY AROUND 12Z MON AND ACRS THE ENTIRE FA BY AROUND 00Z TUE. LATEST ETA BUFR DATA SUPPORT ALL RAIN ACRS THE FA TODAY AND A MIX WITH SOME SN LATER TONITE IN THE NRN ADIRONDACKS AND ACRS THE ENTIRE HIR TRRN OF THE FA ON MON. WILL OPT TO HANDLE ANY POSSIBLE LINGERING SOLID PCPN AND FG ACRS THE FA EARLY THIS MORNING WITH THE STF. LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA ON TUE AFTERNOON. SOME LOW-LVL MSTR TO LINGER ACRS THE FA TONITE THRU EARLY ON MON NITE. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON THRU EARLY ON MON NITE. MID-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON. SOME MID-LVL MSTR TO AFFECT THE FA EARLY TODAY AND AGAIN ON MON. PW VALUES ACRS THE FA LOOK TO BE 0.3-0.4" TONITE AND ON MON. WILL HANG ONTO CHC POPS ACRS THE FA TODAY AND SCHC POPS ACRS THE NRN TIER ZONES TONITE. THE GOING 20-30% POPS FOR MON LOOK PRETTY GOOD AS WELL. DRY WX AND CLEARING SKIES EXPECTED ACRS THE FA ON MON NITE AND TUE. T1MAX TEMPS ARE 40-50F ON MON. T1MIN TEMPS ARE IN THE M20S-U30S TONITE AND IN THE MID TEENS-U20S ON MON NITE. .LONG TERM (TUE NITE ONWARD)... NO CHANGES TO THE GOING FCST FOR NOW...EXCEPT TO MAKE SOME MINOR CHANGES TO MESH UP BETTER WITH SURROUNDING WFOS. PRELIM WRK ZONES AND ISC GRIDS AVAILABLE. ALL FINAL PRODUCTS BY 4 AM. MURRAY .AVIATION... FCST SOUNDINGS SHOW ABUNDANT LOW LVL MSTR PERSISTING THRU THE PD SO EXPECT WDSPRD MVFR AND LOCAL IFR CONDITIONS TO CONT WITH AREAS OF -DZ/BR. SOUNDINGS ACRS NE VT SHOW ISOTHERMAL LAYER NEAR FREEZING THRU ABT 12Z SO AREAS OF SNW/SLEET PSBL HERE ERLY THIS MRNG BEFORE THE COLUMN WARMS. DECREASING 1000-850 MB RH NOTED AT KMSS AND WRN ZONES AFT 21Z WHICH MAY ALLOW CIGS TO LIFT TO VFR LT TDA/TNGT ACROSS THE ST LAW VLY. S TO SW WINDS GENERALLY UNDER 10 KTS SHIFTING TO LGT N/NW LT TDA/TNGT BHND WK SFC TROF. KJC .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ vt AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WILMINGTON OH 1055 AM EST SUN NOV 21 2004 .SHORT TERM (REST OF TODAY)... HIGH PRESSURE CONTINUES TO BUILD IN FROM THE WEST. HOWEVER LOW LEVEL MOISTURE REMAINS INTACT ACROSS THE ILN FA. SOME BREAKS ARE NOTED IN LATEST SAT PICS OVER EXTREME NW OH AND NRN IN. EXPECT VERY LITTLE OF CURRENT CLOUD COVER TO SCOUR OUT...AS ADVECTION PROCESSES ARE NEARLY NIL AND DVV...ALBEIT DEEP...IS QUITE WEAK. ETA SEEMS TO HAVE BEEN DOING WELL WITH HANDLING THIS LOW LEVEL MOISTURE. IT INITIATED WELL AGAIN TODAY...AND CONTINUES TO KEEP MAJORITY OF FA UNDER THIS CLOUD COVER. MID-LEVEL PERTERBATION...WHICH INITIATED WELL WITH THE RUC...WILL EXIT THE SOUTHERN PART OF OUR FA SHORTLY. THIS ALONG WITH SOME BDRY LAYER FORCING THAT WAS NOTED BEST AT 925H ON THE RUC APPEARED TO BE THE PRIMARY CAUSE FOR THE AREA OF LIGHT SPRINKLES THAT AFFECTED A PORTION OF OUR SOUTH-CENTRAL AREA THIS MORNING. SOME WEAK FORCING EXPECTED DURING THE DAY TODAY...BUT NOT ENOUGH TO INITIATE MUCH MORE THAN WIDELY SCATTERED SPRINKLES. TEMPS LOOK GOOD FOR NOW AS WELL. AT MOST WOULD LOWER TODAYS HIGHS BY ABOUT A DEGREE IN SOME LOCATIONS...BUT THIS CHANGE WOULD HAVE VIRTUALLY NO IMPACT. WILL KEEP CURRENT FORECAST PACKAGE AS IS. && .PREVIOUS DISCUSSION... AVIATION(12Z-12Z)... SFC HIGH PRESSURE WILL SLOWLY BUILD SE FROM THE SRN PLAINS INTO THE MIDDLE MS VLY BY 12Z MON. PLENTY OF LOW LVL MSTR EXISTS AT TAF SITES AS SEEN BY CURRENT MVFR CIGS. MVFR CIGS WILL CONTINUE ACRS THE TAF SITES THROUGH THE PERIOD AS LOW LVL MSTR WILL BE HARD PRESSED TO LEAVE REGION (DUE TO LIGHT FLOW WITHIN THE MEAN CLOUD LAYER). WILL TRY TO BRING CLOUD HEIGHTS BRIEFLY ABOVE 3000 FEET ACRS KDAY...KCMH AND KLCK BY LATE IN THE DAY (22Z)...BUT COOLING OVERNIGHT WILL LIKELY BRING THE CLOUD LAYER BELOW 3000 FEET ONCE AGAIN. THE FOLLOWING WAS ORIGINALLY ISSUED AT 345 AM EST SUN NOV 21 2004. SHORT TERM (TODAY THROUGH TUESDAY)... LATEST SURFACE ANALYSIS SHOWING COLD FRONT JUST ABOUT THROUGH OUR AREA WITH PERHAPS A SPRINKLE OR TWO LEFT ACROSS SOUTHEAST PORTIONS OF FA. FRONT SHOULD CONTINUE TO PUSH OUT OF AREA OVER THE NEXT FEW HOURS AND EXPECT ANY LINGERING SPRINKLES TO BE OUT OF FA BY DAYBREAK. OTHERWISE...LOOKS LIKE LOW LEVEL MOISTURE SHOULD HANG IN PRETTY TOUGH THROUGH TODAY AND INTO TONIGHT. AS A RESULT...DO NOT EXPECT TO SEE CLOUDS DISSIPATE IN THE NEAR TERM AND WILL CONTINUE WITH CLOUDY/MOSTLY CLOUDY THROUGH TONIGHT FOR MOST AREAS. EXCEPTION WILL BE ACROSS THE FAR NORTHWEST WHERE SKIES MAY START TO BECOME PARTLY CLOUDY LATER TONIGHT. WITH CLOUDS HANGING AROUND A LITTLE LONGER...HAVE OPTED TO GO A LITTLE COOLER FOR HIGHS TODAY AND A LITTLE WARMER FOR LOWS TONIGHT. SURFACE HIGH FORECAST TO PUSH ACROSS AREA ON MONDAY WHICH SHOULD HELP TO CLEAR OUT SOME OF THE LOWER CLOUDS. HOWEVER...COULD SEE SOME MID AND HIGH LEVEL CLOUDS WORK IN...ESPECIALLY ACROSS THE SOUTH... THROUGH THE AFTERNOON. CLOUDS SHOULD THEN THICKEN UP AND LOWER MONDAY NIGHT AS DEEPER MOISTURE BEGINS TO SPREAD UP FROM THE SOUTH WEST. HOWEVER...BOTH ETA AND GFS HAVE SLOWED UP WITH BRINGING PCPN IN SO WILL PUSH BACK TIMING AND KEEP MONDAY NIGHT DRY. PCPN SHOULD THEN OVERSPREAD THE AREA FROM THE SOUTHWEST THROUGH THE DAY ON TUESDAY. JGL THE FOLLOWING WAS ORIGINALLY ISSUED AT 359 PM EST SAT NOV 20 2004. LONG TERM (TUESDAY THROUGH SATURDAY)... EXTENDED MODELS IN BETTER AGREEMENT TODAY. WILL GENERALLY FOLLOW 00Z GFS SOLUTION. H5 LONGWAVE TROF DIGS THROUGH THE ROCKIES ON TUE...OVERRUNNING PCPN ACROSS A WRMFNT IN THE TN VALLEY WILL WORK NORTH ACROSS THE FA ON TUE/TUE NGT. COLD FRONT SWINGS THROUGH EARLY ON WED. H8 TEMPS DROP FROM +8 TO -4 SO LET TEMPS REBOUND A FEW DEGREES BEFORE HAVING TEMPS FALL DURING THE LATE MORNING AND EARLY AFTERNOON. 1000-850 THICKNESS FALL BELOW 1300M WED NIGHT. WENT AHEAD AND THREW IN A RW/SW MIX WED NGT. WITH H5 TROF AND PVA SWING THRU ON THU AND THU NGT...KEPT MENTION OF CHC RW/SW THU AND SW THU NGT. WEAK HIGH AFFECTS THE AREA FRI...BEFORE ANOTHER H5 SHORTWAVE SWINGS ACROSS THE FA FRI NGT INTO SAT. THICKNESS AND SFC TMPS COLD ENOUGH FOR SNOW AT THE ONSET. OPERATIONAL 00Z GFS WAS THE COLDEST WITH THE H8 TEMPS WED NGT-THU NGT. 06Z WAS A LITTLE WARMER ALONG WITH OTHER 00Z/06Z RUNS...SO WENT ABOVE MEX TEMPS DURING THAT PERIOD. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. IN...NONE. KY...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1005 AM EST SUN NOV 21 2004 .DISCUSSION...ANOTHER CLOUDY MORNING ACROSS THE FORECAST AREA WITH VERY LITTLE RAIN NOTED ON AREA RADARS OR SURFACE OBSERVATIONS. BEST LIFT REMAINS TO OUR SOUTH...AIDED BY RIGHT REAR QUAD OF THE UPPER LEVEL JET. RUC MODEL DOES SPREAD SOME LIGHT RAIN INTO SRN HALF OF THE FORECAST AREA AFTER 18Z TODAY...WHEN SOME WEAK ISENTROPIC LIFT DEVELOPS. THUS...CURRENT FORECAST WITH 30 PERCENT CHANCE NORTH TO 60 PERCENT CHANCE OF RAIN SOUTH LOOKS GOOD FOR THE AFTERNOON. WILL CHECK THE RISE (WHICH WILL BE SLOW) OF TEMPS ACROSS THE AREA TO SEE IF AN UPDATE IS NEEDED. OTHERWISE...THE COVERAGE OF ANY RAIN FOR TONIGHT AND MONDAY LOOKS UNCERTAIN AGAIN. NGM MOS JUST IN LOOKS MUCH TOO HIGH FOR POPS SINCE THE NGM BARELY PRODUCED ANY MEASURABLE RAIN ACROSS THE FORECAST AREA FOR THOSE PERIODS. PROBABLY BEST AT THIS POINT TO STAY WITH THE GFS SOLUTION WITH MOST RAIN PASSING TO OUR SOUTH TONIGHT...THEN MAINLY DRY FOR MONDAY. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 945 AM CST SUN NOV 21 2004 DISCUSSION... ...A DANGEROUS AND LIFE THREATENING FLOOD EVENT UNFLODING ACROSS PARTS OF SOUTHEAST TEXAS... STORMS CONTINUE TO CLUSTER OVER PARTS OF WHARTON...JACKSON AND COLORADO COUNTIES. KHGX-88D IS OVERESTIMATING A BIT...IT APPEARS THAT WHARTON COUNTY HAS RECEIVED IN EXCESS OF 12 INCHES OF RAIN SINCE LAST NIGHT. MANY HOMES ARE INUNDATED AND ROADS ARE IMPASSABLE DUE TO HIGH WATER. THE BOUNDARY RESPONSIBLE FOR THESE TRAINING STORMS IS NEARLY STATIONARY AND DOES NOT APPEAR TO BE MOVING NORTH AT ALL. LATEST RUC MODEL KEEPS THE BNDRY IN PLACE WITH CONVECTION FIRING ALONG AND JUST NORTH OF IT THROUGH EVENING. PW'S ARE NEARLY 200 PERCENT OF NORMAL AND THERE IS DECENT UPPER LEVEL VENTILATION PER SATELLITE IMAGES. WILL MANTAIN FLOOD WATCH TODAY. PREVIOUS FCST HAS THINGS COVERED NICELY AND NO CHANGES ARE REQUIRED. 43 && SLOW NORTHWARD MOVING WARM FRONTAL BOUNDARY EXTENDING FROM NEAR EDNA TO HOUSTON TO NEAR MOSS HILL. STRONG ISENTROPIC LIFTING ESPECIALLY SW ZONES PRODUCING COPIOUS RAINFALL. FLASH FLOOD WARNINGS CONTINUING OVER JACKSON/WHARTON COUNTIES EARLY THIS MORNING WHERE STRONG CLUSTER OF THUNDERSTORMS PERSISTS. PWATS OVER CWFA ABOUT 1.5 TO 1.6 INCHES. FLOOD DECISION TREE AND PRECIP ESTIMATE OBVIOUSLY POINT TO FLOODING POTENTIAL FOR OUR REGION TODAY. WITH SOIL QUITE SATURATED FROM RAINFALL THE PAST FEW DAYS...AND ANTICIPATED CONTINUING WIDESPREAD RAINFALL OVER CWFA...WE SHALL ISSUE A FLOOD WATCH SHORTLY FOR TODAY. WARM AIR AND MOISTURE ADVECTION BOTH EVIDENT AT 850 AND 700 MB LEVELS (WITH GOOD INFLOW AT 850 MB). MODELS SHIFTING FOCUS OF RAINFALL TO THE NORTHWEST TONIGHT. WARM FRONTAL BOUNDARY EXPECTED TO GRADUALLY PUSH NORTH TODAY. THIS SHOULD SHIFT RAINFALL FOCUS TO NORTHERN ZONES BUT STILL A GOOD CHANCE AREAWIDE WITH HIGH PWATS AND UPPER LEVEL JET NEARBY. THIS SCENARIO WILL CONTINUE THROUGH EARLY NEXT WEEK. UPPER LOW WILL MOVE TO WEST TEXAS EARLY TUESDAY AND THEN RAPIDLY SWING NORTHEAST WHILE OPENING INTO A TROUGH. DRYING WEST TO EAST EXPECTED BY TUESDAY AFTERNOON. COLD FRONT WILL PUSH THROUGH REGION TUESDAY NIGHT. WEDNESDAY AND REST OF WEEK WILL SEE DRY AND COOL WEATHER. A COLD FRONT IS INDICATED BY GFS TO MOVE ACROSS TEXAS SUNDAY. AVIATION...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER CWFA TODAY WITH CEILINGS AT OR SLIGHTLY BELOW IFR CONDITIONS. VISIBILITIES TEMPORARILY LOWERING TO BELOW IFR CONDITIONS IN PASSING SHOWERS. MARINE...WE SHALL HAVE CAUTION FOR BAYS AND 0-20 NM COASTAL WATERS WITH SCA 20-60 COASTAL WATERS. SOUTH TO SOUTHEAST WINDS HAS BEEN INCREASING IN RESPONSE TO TIGHTENING OF PRESSURE GRADIENT NEAR THE COAST. WAVE HEIGHTS GRADUALLY INCREASING THE LAST FEW HOURS AND NOW RUNNING 5 FEET 20-60 NM REGION. 37/45 && .HGX WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH ALL HGX CWFA UNTIL 6 PM TODAY. SCEC BAYS AND 0-20 NM COASTAL WATERS. SCA 20-60 NM COASTAL WATERS. && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 73 66 74 66 73 / 80 80 60 80 70 HOUSTON (IAH) 77 68 76 68 76 / 80 60 50 60 70 GALVESTON (GLS) 78 72 77 71 78 / 80 40 30 50 70 && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1040 AM EST SUN NOV 21 2004 .UPDATED DISCUSSION... WDLY SCT -SHRA ACRS FA ATTM WITH NOT MUCH ACTVTY UPSTREAM, BUT IN VCNTY OF SFC TROF AND SOME EMBEDDED VORT LOBES FEEL SLGT/CHC WRDG STL WORKS. TMPS ARE WELL WITHIN XPCTD RANGES AND ABV FRZG, THUS NO CONCERNS THERE AS WELL. PRVS FCST HAS GOOD HNDL ON FCST...THUS NO UPDATE NEEDED. && .PREVIOUS DISCUSSION... .SYNOPSIS... FRONTAL SYS TO MOVE ACRS THE FA FROM THE WEST TODAY AND EARLY TONITE. HI PRESS TO BUILD INTO THE FA FROM THE WEST LATER TONITE THRU MON NITE...THEN MOVE OFF TO THE EAST OF THE FA ON TUE. UPR TROF TO MOVE ACRS THE FA ON MON. S/W TO MOVE TO THE NORTH OF THE FA ON TUE. .SHORT TERM (THROUGH TUE)... 00-03Z 13KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE M30S-M40S TODAY WITH SOUTHERLY SFC WINDS FOR MUCH OF THE DAY AT 5-10 KTS. T1MAX TEMPS ARE IN THE 50S TODAY AND LOOK WAY TOO WARM BASED ON EXPECTED CLD COVER AND PCPN CHCS. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA. LOW-LVL MSTR TO CONT AFFECT THE FA FOR MUCH OF TODAY. PW VALUES ACRS THE FA TO BE 0.3-0.8" TODAY. RUC SHOWS CLDY SKIES AND SCT SHRA ACRS THE FA TODAY. BUFCAN/88D MOSAIC SHOWS JUST SOME SCT PCPN ACRS THE FA ATTM. NO BINOVC NOTED IN REGIONAL IR SAT PIX ATTM. EARLIER...AT LEAST A MIX WITH PL/SN WAS OCCURRING ACRS PARTS OF NE/NC VT AND ALONG THE SPINE OF THE GREEN MTNS IN SRN VT...WITH AT LEAST AN INCH OF MEASURABLE SN AT SUTTON VT. H85 CAA TO TAKE PLACE ACRS THE FA TODAY THRU MUCH OF MON...THEN WAA TO DEVELOP ACRS THE FA ON MON NITE/TUE. H85 TEMPS TO GO NEGATIVE ACRS THE FA BY 00-06Z TONITE. H925 WET-BULB TEMPS TO GO NEGATIVE ACRS THE NRN TIER ZONES BY AROUND 12Z MON AND ACRS THE ENTIRE FA BY AROUND 00Z TUE. LATEST ETA BUFR DATA SUPPORT ALL RAIN ACRS THE FA TODAY AND A MIX WITH SOME SN LATER TONITE IN THE NRN ADIRONDACKS AND ACRS THE ENTIRE HIR TRRN OF THE FA ON MON. WILL OPT TO HANDLE ANY POSSIBLE LINGERING SOLID PCPN AND FG ACRS THE FA EARLY THIS MORNING WITH THE STF. LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA ON TUE AFTERNOON. SOME LOW-LVL MSTR TO LINGER ACRS THE FA TONITE THRU EARLY ON MON NITE. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON THRU EARLY ON MON NITE. MID-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON. SOME MID-LVL MSTR TO AFFECT THE FA EARLY TODAY AND AGAIN ON MON. PW VALUES ACRS THE FA LOOK TO BE 0.3-0.4" TONITE AND ON MON. WILL HANG ONTO CHC POPS ACRS THE FA TODAY AND SCHC POPS ACRS THE NRN TIER ZONES TONITE. THE GOING 20-30% POPS FOR MON LOOK PRETTY GOOD AS WELL. DRY WX AND CLEARING SKIES EXPECTED ACRS THE FA ON MON NITE AND TUE. T1MAX TEMPS ARE 40-50F ON MON. T1MIN TEMPS ARE IN THE M20S-U30S TONITE AND IN THE MID TEENS-U20S ON MON NITE. .LONG TERM (TUE NITE ONWARD)... NO CHANGES TO THE GOING FCST FOR NOW...EXCEPT TO MAKE SOME MINOR CHANGES TO MESH UP BETTER WITH SURROUNDING WFOS. PRELIM WRK ZONES AND ISC GRIDS AVAILABLE. ALL FINAL PRODUCTS BY 4 AM. MURRAY .AVIATION... FCST SOUNDINGS SHOW ABUNDANT LOW LVL MSTR PERSISTING THRU THE PD SO EXPECT WDSPRD MVFR AND LOCAL IFR CONDITIONS TO CONT WITH AREAS OF -DZ/BR. SOUNDINGS ACRS NE VT SHOW ISOTHERMAL LAYER NEAR FREEZING THRU ABT 12Z SO AREAS OF SNW/SLEET PSBL HERE ERLY THIS MRNG BEFORE THE COLUMN WARMS. DECREASING 1000-850 MB RH NOTED AT KMSS AND WRN ZONES AFT 21Z WHICH MAY ALLOW CIGS TO LIFT TO VFR LT TDA/TNGT ACROSS THE ST LAW VLY. S TO SW WINDS GENERALLY UNDER 10 KTS SHIFTING TO LGT N/NW LT TDA/TNGT BHND WK SFC TROF. KJC .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ vt AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WILMINGTON OH 115 PM EST SUN NOV 21 2004 .AVIATION(18Z-18Z)... HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE AREA. WINDS ARE BEGINNING TO GO LGT AND VARIABLE...AND WILL REMAIN SUCH THROUGH THIS FORECAST PACKAGE. THE PROBLEM WILL BE THE LOW-LEVEL MOISTURE. KDAY AND KCMH WILL BE NEAR THE BOUNDARY OF WHERE BREAKS WILL DEVELOP THIS AFTERNOON. BUT AS OF NOW...WILL KEEP ALL ILN TAF SITES IN IFR/MVFR CATEGORIES FOR CIGS THROUGH THE PERIOD. THERE APPEARS TO BE A WEAK MID-LEVEL PERTURBATION THAT WILL WORK ITS WAY OF THE SRN PLAINS OVERNIGHT...AND PROVIDE A SLT CHANCE FOR RAIN SHOWERS OR SPRINKLES ACROSS THE KCVG KLUK SITES AROUND 12Z MONDAY. VERY LITTLE IN THE WAY OF SUPPORT FOR THIS. ISENTROPIC LIFT ALSO NOT VERY FAVORABLE. SO AT THIS TIME HAVE DECIDED TO PLACE VCSH FOR A FEW HOURS AT THESE TWO SITES BEGINNING AROUND 09Z. && .PREVIOUS DISCUSSION... SHORT TERM (REST OF TODAY)... HIGH PRESSURE CONTINUES TO BUILD IN FROM THE WEST. HOWEVER LOW LEVEL MOISTURE REMAINS INTACT ACROSS THE ILN FA. SOME BREAKS ARE NOTED IN LATEST SAT PICS OVER EXTREME NW OH AND NRN IN. EXPECT VERY LITTLE OF CURRENT CLOUD COVER TO SCOUR OUT...AS ADVECTION PROCESSES ARE NEARLY NIL AND DVV...ALBEIT DEEP...IS QUITE WEAK. ETA SEEMS TO HAVE BEEN DOING WELL WITH HANDLING THIS LOW LEVEL MOISTURE. IT INITIATED WELL AGAIN TODAY...AND CONTINUES TO KEEP MAJORITY OF FA UNDER THIS CLOUD COVER. MID-LEVEL PERTERBATION...WHICH INITIATED WELL WITH THE RUC...WILL EXIT THE SOUTHERN PART OF OUR FA SHORTLY. THIS ALONG WITH SOME BDRY LAYER FORCING THAT WAS NOTED BEST AT 925H ON THE RUC APPEARED TO BE THE PRIMARY CAUSE FOR THE AREA OF LIGHT SPRINKLES THAT AFFECTED A PORTION OF OUR SOUTH-CENTRAL AREA THIS MORNING. SOME WEAK FORCING EXPECTED DURING THE DAY TODAY...BUT NOT ENOUGH TO INITIATE MUCH MORE THAN WIDELY SCATTERED SPRINKLES. TEMPS LOOK GOOD FOR NOW AS WELL. AT MOST WOULD LOWER TODAYS HIGHS BY ABOUT A DEGREE IN SOME LOCATIONS...BUT THIS CHANGE WOULD HAVE VIRTUALLY NO IMPACT. WILL KEEP CURRENT FORECAST PACKAGE AS IS. THE FOLLOWING WAS ORIGINALLY ISSUED AT 345 AM EST SUN NOV 21 2004. SHORT TERM (TODAY THROUGH TUESDAY)... LATEST SURFACE ANALYSIS SHOWING COLD FRONT JUST ABOUT THROUGH OUR AREA WITH PERHAPS A SPRINKLE OR TWO LEFT ACROSS SOUTHEAST PORTIONS OF FA. FRONT SHOULD CONTINUE TO PUSH OUT OF AREA OVER THE NEXT FEW HOURS AND EXPECT ANY LINGERING SPRINKLES TO BE OUT OF FA BY DAYBREAK. OTHERWISE...LOOKS LIKE LOW LEVEL MOISTURE SHOULD HANG IN PRETTY TOUGH THROUGH TODAY AND INTO TONIGHT. AS A RESULT...DO NOT EXPECT TO SEE CLOUDS DISSIPATE IN THE NEAR TERM AND WILL CONTINUE WITH CLOUDY/MOSTLY CLOUDY THROUGH TONIGHT FOR MOST AREAS. EXCEPTION WILL BE ACROSS THE FAR NORTHWEST WHERE SKIES MAY START TO BECOME PARTLY CLOUDY LATER TONIGHT. WITH CLOUDS HANGING AROUND A LITTLE LONGER...HAVE OPTED TO GO A LITTLE COOLER FOR HIGHS TODAY AND A LITTLE WARMER FOR LOWS TONIGHT. SURFACE HIGH FORECAST TO PUSH ACROSS AREA ON MONDAY WHICH SHOULD HELP TO CLEAR OUT SOME OF THE LOWER CLOUDS. HOWEVER...COULD SEE SOME MID AND HIGH LEVEL CLOUDS WORK IN...ESPECIALLY ACROSS THE SOUTH... THROUGH THE AFTERNOON. CLOUDS SHOULD THEN THICKEN UP AND LOWER MONDAY NIGHT AS DEEPER MOISTURE BEGINS TO SPREAD UP FROM THE SOUTH WEST. HOWEVER...BOTH ETA AND GFS HAVE SLOWED UP WITH BRINGING PCPN IN SO WILL PUSH BACK TIMING AND KEEP MONDAY NIGHT DRY. PCPN SHOULD THEN OVERSPREAD THE AREA FROM THE SOUTHWEST THROUGH THE DAY ON TUESDAY. JGL THE FOLLOWING WAS ORIGINALLY ISSUED AT 359 PM EST SAT NOV 20 2004. LONG TERM (TUESDAY THROUGH SATURDAY)... EXTENDED MODELS IN BETTER AGREEMENT TODAY. WILL GENERALLY FOLLOW 00Z GFS SOLUTION. H5 LONGWAVE TROF DIGS THROUGH THE ROCKIES ON TUE...OVERRUNNING PCPN ACROSS A WRMFNT IN THE TN VALLEY WILL WORK NORTH ACROSS THE FA ON TUE/TUE NGT. COLD FRONT SWINGS THROUGH EARLY ON WED. H8 TEMPS DROP FROM +8 TO -4 SO LET TEMPS REBOUND A FEW DEGREES BEFORE HAVING TEMPS FALL DURING THE LATE MORNING AND EARLY AFTERNOON. 1000-850 THICKNESS FALL BELOW 1300M WED NIGHT. WENT AHEAD AND THREW IN A RW/SW MIX WED NGT. WITH H5 TROF AND PVA SWING THRU ON THU AND THU NGT...KEPT MENTION OF CHC RW/SW THU AND SW THU NGT. WEAK HIGH AFFECTS THE AREA FRI...BEFORE ANOTHER H5 SHORTWAVE SWINGS ACROSS THE FA FRI NGT INTO SAT. THICKNESS AND SFC TMPS COLD ENOUGH FOR SNOW AT THE ONSET. OPERATIONAL 00Z GFS WAS THE COLDEST WITH THE H8 TEMPS WED NGT-THU NGT. 06Z WAS A LITTLE WARMER ALONG WITH OTHER 00Z/06Z RUNS...SO WENT ABOVE MEX TEMPS DURING THAT PERIOD. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. IN...NONE. KY...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1100 AM CST SUN NOV 21 2004 .DISCUSSION...LATEST SURFACE ANALYSIS THIS MORNING PLACES WEAK STATIONARY BOUNDARY ACROSS THE MID SOUTH WITH ANOTHER STATIONARY BOUNDARY ACROSS THE GULF COAST. VISIBLE SATELLITE SHOWS MOSTLY OVERCAST CONDITIONS ACROSS MUCH OF THE REGION WITH ONLY A FEW BREAKS ACROSS SOUTHEAST MISSOURI. MAIN FORECAST CONCERNS THIS AFTERNOON IS PRECIPITATION CHANCES...CLOUD COVER AND TEMPERATURES. RAINFALL ACROSS THE MID SOUTH ALREADY STARTING TO DIMINISH OVER THE PAST COUPLE OF HOURS. A WEAK VORTICITY MAX WILL MOVE ACROSS NORTHERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON. MESOETA MODEL SOUNDINGS QUITE A BIT DRIER THAN RUC SOUNDINGS. LATEST 88D RADAR TRENDS SHOW MAIN BATCH OF RAINFALL ACROSS NORTHERN MISSISSIPPI MOVING EAST WITH VERY LIGHT RETURNS ACROSS ARKANSAS AND WESTERN TENNESSEE...ENOUGH TO PRECIPITATE OUT. MESOETA MODEL SOUNDINGS TRY TO BRING QUITE A BIT OF MID LEVEL DRY AIR INTO THE AREA RATHER QUICKLY COMARED TO THE MOISTER RUC. BASED ON RUC ANALYSIS AND CURRENT RADAR/OBSERVATIONAL TRENDS...I WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST WITH PRECIPITATION DIMINISHING TO DRIZZLE BY THIS EVENING. TEMPERATURES WILL NOT RECOVER MUCH...MAYBE A FEW DEGREES HIGHER THAN CURRENT OBSERVATIONS WITH AMPLE CLOUD COVER EXPECTED INTO THE AFTERNOON. UPDATED GRIDS WILL BE OUT SHORTLY. CJC .PREV DISCUSSION...ISSUED 218 AM CST SUN NOV 21 2004... THERE SHOULD BE A RELATIVE MINIMUM OF PRECIPITATION LATE THIS AFTERNOON THROUGH ABOUT MID-DAY ON MONDAY...IN BETWEEN IMPULSES. WILL ONLY HAVE 20-30 POPS TONIGHT. LIKELY POPS TO SPREAD FROM SOUTHWEST TO NORTHEAST DURING THE DAY ON MONDAY. LIKELY POPS AREA-WIDE MONDAY NIGHT...WITH BOUNDARY PUSHING NORTH... MOST PRECIPITATION WILL BE STRATIFORM UNTIL LATE IN THE NIGHT. UPPER SYSTEM KICKS FRONT/DRY SLOT THROUGH THE AREA TUESDAY AFTERNOON AND TUESDAY NIGHT. LIFTED INDICES ARE NEGATIVE ON TUESDAY WITH CAPES IN THE 500-1000 RANGE. AGREE WITH MODEL GUIDANCE CATEGORICAL POPS FOR TUESDAY AND TUESDAY NIGHT. WHILE POTENTIAL FOR SEVERE WILL NOT BE MENTIONED IN ZONES AT THIS TIME...IT WILL BE MENTIONED IN THE HWO. DRY SLOT MOVES THROUGH EARLY WEDNESDAY MORNING. MODELS INDICATE THAT THERE COULD BE SOME WRAP AROUND LIGHT PRECIPITATION SO WILL KEEP SMALL POPS FOR WEDNESDAY. TEMPERATURES SHOULD BE A FEW DEGREES COOLER TODAY THAN ON SATURDAY... WITH SIMILAR HIGHS EXPECTED ON MONDAY. DON'T SEE MUCH CHANGE IN OVERNIGHT LOWS TONIGHT. AS WINDS GET A SOUTHERLY COMPONENT MONDAY NIGHT...LOWS WILL BE A LITTLE WARMER. WILL TREND WARMER THAN GFS FOR HIGHS TUESDAY...AS SOUTHERLY FLOW BECOMES WELL ESTABLISHED. MOVEMENT OF FRONT WILL BE MAIN FACTOR IN TUESDAY NIGHT LOWS/WEDNESDAY HIGHS. && .LONG TERM (BEYOND WEDNESDAY)... SEE NO REASON TO MAKE SIGNIFICANT CHANGES TO SENSIBLE WEATHER IN EXTENDED. GFS TEMPERATURES HAVE COME AROUND FROM LAST NIGHT'S RUN... AND ARE FAIRLY CLOSE TO WHAT WE HAVE RUNNING. && .MEG...WATCHES/WARNINGS/ADVISORIES... AR...NONE. MS...NONE. MO...NONE. TN...NONE. && $$ WAGNER tn