AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE GOODLAND KS 1103 AM MST SUN DEC 22 2002 ALL MODELS NOT DOING WELL WITH WIND AND TEMPERATURE FIELDS THIS MORNING. CURRENTLY HAVE SOUTHERLY WINDS OF 10 TO 20 MPH IN SOUTHWEST PORTION OF THE FORECAST AREA. RUC WHICH LOOKS THE CLOSEST HAS WINDS CONTINUING LIGHT AND VARIABLE/LIGHT EASTERLY IN NORTH AND EASTERN PORTIONS OF THE FORECAST AREA TO SHIFTING TO THE EAST AND SOUTHEAST OVER THE SOUTHWEST LOCATIONS. BASED ON RUC AND CURRENT OBSERVATIONS...WILL GO IN THAT DIRECTION. ALSO MODELS ARE TOO COOL IN WESTERN PORTION OF THE AREA WITH TEMPERATURES NEAR OR AT FORECAST MAXES. ALSO THICKER CLOUD COVER NOT SURGING IN AS FAST CURRENT FORECAST EXPECTED WHICH IS ALLOWING THE CURRENT RISE. SO WILL UP TEMPERATURES IN WESTERN PORTION OF AREA 3 TO 5 DEGREES...AND WILL MAKE/KEEP CLOUD COVER MOSTLY SUNNY OR BECOMING PARTLY SUNNY. .GLD...NONE. BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 931 PM EST SUN DEC 22 2002 KMQT/MONTREAL RIVER RADARS SHOW RESPECTABLE LAKE EFFECT SNOW (LES) BANDS CONTINUING TO IMPACT CHIPPEWA COUNTY NORTH OF M-28... ESPECIALLY NEAR WHITEFISH. HOWEVER...THESE GENERALLY AREN/T STAYING IN ANY ONE PLACE FOR LONG. IN NORTHERN LOWER...LES IS MORE BLOBULAR WITH LIMITED BANDING. THOUGH REFLECTIVITIES HAVE BEEN REASONABLY IMPRESSIVE (LARGE AREA OF 20-28DBZ RETURNS EARLIER THIS EVENING)... VSBYS HAVE REALLY STRUGGLED TO DROP LOWER THAN 3SM. ACCUMS HAVE BEEN WELL UNDER AN INCH. IR LOOP SHOWS A BAND OF MID-LEVEL MOISTURE FEEDING EAST ACROSS CENTRAL LOWER MI...ASSOCIATED WITH THE BEST RETURNS LEFT ON KAPX RADAR. EASTERN UPPER...MAIN CONCERN IS WHETHER BANDS WILL CONTINUE TO IMPACT WHITEFISH PT AREA OVERNIGHT. LATEST RUC SHOWS 1000-850MB WINDS BACKING A SMIDGE MORE WESTERLY DURING THE NIGHT...REACHING ABOUT 275/280 BY 09Z. KMQT RADAR/IR IMAGERY MAY BE SHOWING THIS TREND BEGINNING...AS WSW ORIENTED BANDS ARE STARTING TO TRANSLATE EAST. THUS...LES BANDS SHOULD MAKE FEWER INROADS INTO THE SAULT OVERNIGHT...WITH THE MOST THREATENED AREA BEING RIGHT AROUND WHITEFISH PT. WILL MAKE A FEW ADJUSTMENTS TO WORDING IN CHIPPEWA COUNTY TO ACCOUNT FOR THIS. NORTHERN LOWER...IN LINE WITH RADAR AND MODEL TRENDS WILL BE REDUCING SNOW MOST AREAS. CONDITIONS BECOME INCREASINGLY HOSTILE TO LES OVERNIGHT...ESPECIALLY IN THE WAKE OF THE MID LEVEL MOISTURE NOW IN THE SOUTHERN ZONES. AIRMASS DRIES CONSIDERABLY ABOVE THE INVERSION...WITH MOISTURE REACHING AROUND -9/-10C ACCORDING TO THE ETA...-12C BY THE RUC. COMBINED WITH LIMITED LAKE RESIDENCE TIME... AND LES SHOULD BE FAIRLY WIDESPREAD BUT LIGHT. IN FACT... MOISTURE BECOMES LIMITED ENOUGH OVERNIGHT TO PROVIDE SOME FROZEN DRIZZLE CONCERNS...ESPECIALLY IF THE ETA IS RIGHT. GIVEN -FZDZ HAS BEEN OBSERVED IN PARTS OF WESTERN UPPER MI THIS EVENING...WILL ADD PATCHY FZDZ POSSIBLE LATE TONIGHT IN UPSLOPE-FAVORED AREAS IN NW/N CENTRAL LOWER. IN THE SOUTHEAST...BAND OF MID LEVEL MOISTURE WILL MAKE IT EASIER THAN IS TYPICAL FOR LES TO PENETRATE INLAND AND OFF THE HIGHER ELEVATIONS. WILL ADD POPS TO THE FAR SE CORNER WITH SMALL LOCAL ACCUMS. .APX...WINTER WEATHER ADVISORY THROUGH MONDAY MORNING CHIPPEWA CO. ZOLTOWSKI mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 500 AM EST SUN DEC 22 2002 MAIN FCST CONCERNS ARE LES TRENDS THROUGH MON. WV IMAGERY AND RUC ANALYSIS INDICATED STACKED LO JUST E OF JAMES BAY WITH SPOKES OF SHRTWV ENERGY CONTINUING TO ROTATE AROUND THIS FEATURE. ONE SHRTWV OR VORT LOBE WITH ASSOCIATED COLDER TOPS...PER IR LOOP...EXTENDED ACRS LK SUPERIOR WHILE A STRONGER VORT WAS LOCATED TO THE NORTH NEAR CYGQ (GERALDTON). IR/WV LOOPS ALSO SHOWED WEDGE OF DRIER AIR MOVING IN FROM NW ONTARIO. UPSTREAM OBS INDICATED INCREASE IN -SN WITH VSBYS GENERALLY IN THE 3-5SM RANGE OVER NE MN DESPITE INCREASE IN MID AND UPR LVL MOISTURE OVER THE NRN HLF OF THE LAKE...LES INTENSITY HAS BEEN SLOW TO RESPOND WITH MAIN VSBY REDUCTION AT KCMX FROM BLSN (OBSERVER REPORTS OF LCL VERY LO VSBY IN OPEN AREAS) WHILE HOUGHTON AREA WEBCAMS INDICATED LITTLE VSBY REDUCTION. KMQT 88D INDICATED INCREASING RETURNS WITH MID CLD MOVING IN AND MAIN W-E LES BAND FROM N OF THE THE HURON ISLANDS TO N OF GRAND MARAIS WHICH WAS IN REASONABLE AGREEMENT WITH ETA 950 MB WINDS AND MAX CONVERGENCE. MDL DIFFERENCES AGAIN INVOLVE PLACEMENT/TIMING/INTENSITY OF SHRTWV FEATURES MOVING INTO THE WRN LAKES...ESPECIALLY BY 36 HRS. BY MON THE GFS WAS CONSIDERABLY SLOWER (ABOUT 6 HRS) THAN THE 00Z ETA TO BRING THE MAIN SHRTWV/VORT THROUGH LK SUPERIOR. THE UKMET...IN BTWN THE TWO...LOOKED LIKE A REASONABLE COMPROMISE AND IS IN LINE WITH THE 06Z ETA TREND. IN THE SHORTER TERM...HAVE RELIED ON ETA FOR LOW LVL WIND FIELD DETAILS FOR GUIDANCE WITH LES PLACEMENT. TODAY...EXPECT LES THIS MORNING ASSOCIATED WITH ENHANCEMENT FROM FIRST SHRTWV AND BATCH OF DEEPER MOISTURE WILL DIMINISH BY MIDDAY A DNVA AND WEDGE OF DRIER 800-600 MB LYR AIR MOVE IN FROM 12Z-18Z. SO...HAVE KEPT RELATIVELY MODEST 1-4 INCH RANGE SNOW FCST. HOWEVER...WITH ONGOING LES AND BLOWING SNOW AND LCL POOR VISIBILITY OVER THE KEWEENAW...WHICH IS MOST SUSCEPTIBLE TO GUSTY W WINDS...HAVE LEFT LAKE EFFECT SN BLSN ADVY IN PLACE THIS MORNING. OVER THE EAST...ONLY SLIGHT VEERING TREND FCST WHICH WOULD BRING SOME LES ONSHORE...MAINLY FOR LOCATIONS FROM GRAND MARAIS EASTWARD. LITTLE ACCUMULATION EXPECTED OVER THE REST OF UPR MI. TONIGHT INTO MON...MDLS SUGGEST INCREASE IN 800-500 MOISTURE AND ARRIVAL OF SLIGHTLY COLDER AIR TOWARD 00Z/MON AND RISIING INVERSION HGTS...BRINGING LAKE INDUCED CAPE CLIMBS TO NEAR 400 J/KG BY 06Z...WILL BOOST LES INTENSITY. ETA LOW LVL WINDS/CONVERGENCE FAVORED LOCATIONS SHIFTING FROM NRN PORTION OF TH KEWEENAW GRADUALLY SOUTHWARD TO AREA BTWN ONTONAGON AND HOUGHTON. MDL QPF PATTERNS/AMOUNTS...AND LCL LES GUIDANCE SUGGESTS AMOUNTS UP TO 7 INCHES TONIGHT AND 5 INCHES MON WHICH WOULD JUSTIFY CONTINUATION OF HEAVY LES WATCH. HAVE NOT UPGRADED NW UPR MI TO WARNING...IN ORDER TO KEEP TONIGHT'S MORE SIGNFICANT LES DISTINCT FROM TODAYS ONGOING WIND/LES AND MIDDAY LULL. FARTHER SW NEAR KIWD...ALTHOUGH MAINLY WRLY 1000-900 WINDS WILL LIMIT LES POTENTIAL...850 MB WINDS TO NEAR 310 MAY PUSH SOME LES BANDS INTO THE AREA BUT WITH AMOUNTS TO 3 INCHES LATE TONIGHT AND AGAIN MON. OVER E PORTION OF UPR MI...EXPECT LES TO PUSH FARTHER INLAND AS WINDS GRADUALLY VEER. AMOUNTS OF UP TO 6 INCHES TONIGHT AND 5 INCHES MON ALSO JUSTIFY CONTINUANCE OF THE WATCH. FCST CONVERGENCE ZONE WOULD KEEP HEAVIEST AMOUNTS GENERALLY E OF MUNISING AND NORTH OF M-28. BY MON AFTERNOON EXPECT LES TO DIMINISH IN INTENSITY AS THE VORT AND H8 THERMAL TROF MOVE ON THE EAST. HEAVIER LES MAY LINGER OVER THE ERN CWA INTO MON AFTERNOON THOUGH...ESPECIALLY IF 00Z GFS SCENARIO OCCURS. OVER THE REST OF UPR MI...STRENGTH OF THE SHRTWV AND AMOUNT OF DEEP MOISTURE AND RESIDUAL LAKE MOISTURE DOWNSTREAM FROM HIGHER TERRAIN MAY BE ENOUGH TO SQUEEZE OUT SOME LIGHT ACCUMULATIONS OF AROUND A HALF INCH OVER CNTRL UPR MI...VCNTY OF MARQUETTE-ISHPEMING. TEMPS GENERALLY NEAR GUIDANCE AND CURRENT FCST VALUES LOOKED ON TRACK. .MQT...LAKE EFFECT SN AND BLSN ADVY MIZ001 TODAY THROUGH MON MORN. LAKE EFFECT SN AND BLSN ADVY MIZ002-003-084 TODAY. WINTER STORM WATCH TONIGHT THROUGH MON MORNING MIZ002-003-084. WINTER STORM WATCH TONIGHT THRU MON MIZ006-007-085. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 850 PM CST SUN DEC 22 2002 LATEST IR IMAGERY GEARED TOWARD LOW CLOUDS SHOWS DRY AIR FILTERING SEWD INTO NERN ND AND A SMALL BIT OF NW MN...MAINLY ALONG THE RED RIVER VALLEY. KGFK JUST SCATTERED OUT AND KFAR HAS GONE BROKEN. LATEST RUC AND MESOETA BOTH SHOW SIG MOISTURE IN LOWEST THOUSAND FEET REMAINING ACROSS MOST OF AREA THROUGH MOST OF THE NIGHT. DRY AIR WILL LIKELY REACH AXN/MOX AREA...BUT CNTRL MN INTO WC WISC IS MORE QUESTIONABLE. WL KEEP CLOUDS IN THIS AREA...SCATTER IT OUT IN CNTRL AND SC MN AFTER SUNRISE...THEN SEE MORE COME IN LATER MONDAY PER PREV FCST. WITH MORE CLOUDS HANGING IN THERE...MIN TEMPS TONIGHT WL NOT BE QUITE SO COOL. .MSP...NONE. $$ TDK mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 945 PM EST SUN DEC 22 2002 RETURNS FROM LOCAL RADARS HAVE INCREASED IN INTENSITY ACROSS THE EASTERN SHORE OF LAKE ONTARIO. KTYX SHOWS SOUTHERN MOST EXTENSION OF BAND OVER NRN ONEIDA COUNTY. VAD WIND PROFILES INDICATE A GENERAL 270 FLOW THROUGH THE UNSTABLE LAYER. ETA BUFKIT PROFILES ALONG WITH RUC INDICATE FLOW WILL BACK SLIGHTLY AFTER 06Z AND MOVE BULK OF LES BAND NORTH OF ONEIDA COUNTY. EXPECT SEVERAL HOURS OF LES OVER NRN ONEIDA COUNTY UNTIL IT SHIFTS NORTHWARD. FLOW IS WELL ALIGNED WITH A SUFFICIENT UNSTABLE LAYER BUT LIMITING FACTOR IS LAKE INDUCED CAPE. WITH LIMITED DURATION AND LACK OF SIGNIFICANT INSTABILITY WILL UP AMOUNTS TO 2 TO 4 INCHES ACROSS NRN ONEIDA COUNTY. REST OF FORECAST UNCHANGED. RRM ...PREVIOUS AFD... BIG PICTURE...STRONG 500MB PAC JET CONTINUES TO SPLIT JUST TO THE WEST OF N AM COAST. PATTERN ACROSS US LOOKS VERY TRANSITORY OVER THE NEXT WEEK...AS PATTERN VARIES FROM NEUTRAL TO WEAKLY POSITIVE PNA. SHORT TERM...WEAK SFC TROUGH/COLD FRONT MOVING ACROSS CWA ATTM. NOT PRODUCING ANYTHING BUT WEAK RADAR ECHOS. ONCE FRONT PASSES...WINDS SHIFT BACK TO MORE OF A WESTERLY DIRECTION...AND THE LAKES WILL COME INTO PLAY AGAIN TONIGHT. LOOKS LIKE A PERSISTENT SINGLE BAND WILL DEVELOP OFF LAKE ONTARIO AS 850MB TEMPS DROP BACK TO ~10C OVERNIGHT...AND INVERSION HGT CREEPS UP TO ABOVE 800MB BY MON MORNING. ONT BAND SHOULD FORM ON INIT 260/270 LINE...BUT WILL PROBABLY FLUCTUATE A LITTLE SOUTHWARD AROUND OR AFTER MIDNIGHT. WILL GO WITH ACCUMULATING SNOW NRN ONEIDA...AND TO LESSER EXTENT WRN MOHAWK VLY. BAND WILL SHIFT TO THE N AGAIN MON AFT...IN RESPNONSE TO APPROACHING 500MB SHORT WAVE. LAKE ERIE BAND IS LIKELY TO PRODUCE SOME SCT SNSH OR FLURRIES INTO THE SRN TIER OF NY AND NRN TIER OF PA INTO MON AM. ONCE SHORTWAVE PASSES EARLY MONDAY EVE...SLIGHTLY COLDER AIR WILL FILTER IN ON NW WINDS...PRODUCING MULTI-BANDS INTO THE WRN MOHAWK VLY...AND THE UPPER SUSQ REGION. THIS WAVE AND ASSOCIATED SFC TROUGH MAY PRODUCE SOME PRECIP ACROSS ENTIRE CWA LATE MON. FLOW WEAKENS AND SHIFTS TO SW ON TUESDAY...SO ANY LAKE EFFECT WILL WANE ON TUES AM. 500MB CLOSED LOW WILL BE TRACKING EASTWARD OVER NEW BRUNSWICK ON TUESDAY...AND MID/UPPER FLOW WILL BE COMING FROM MORE OF A TRUE WESTERLY DIRECTION...WHICH COULD SPELL SOME CLEARING FOR A GOOD PART OF TUESDAY. MAX/MINS WILL DROP OFF A COUPLE DEGREES EVERY DAY AS SERIES OF WAVES TAPS INTO COLDER AIRMASS NORTH OF THE BORDER. MAV/FWC BLEND WILL WORK WELL...WITH A FEW MINOR TWEAKS. EXTENDED...12Z MODELS HAVE COME CLOSER TO AGREEING THAT SYSTEM EXITING THE GULF STATES TUESDAY WILL REDEVLOP OFF THE CAROLINA COAST AND TRACK ENE...STILL SOUTH OF THE 40/70 BENCHMARK BY 00Z/26. ALTHOUGH FORECAST CONIFIDENCE STILL NOT HIGH...IT HAS INCREASED A BIT. GFS/ETA IN FAIRLY GOOD AGREEMENT WITH TRACK...BUT DIFFER SOMEWHAT ON INTENSITY AND TIMING. THE CANADIAN IS ALSO CLOSE...BUT FASTER...WHILE THE ECMWF HANGS ON TO THE INLAND LOW UNTIL IT REACHES NEAR KPIT...BUT THEN REDEVELOPS COASTAL LOW WAY OFF NEW JERSEY COAST. WILL LEAN TOWARD THE GFS/ETA TRACK WHICH WOULD MEAN LITTLE OR NO SNOW N AND W OF SRN TIER...WITH AMOUNTS INCREASING TO THE S AND E. WILL NOT TRY TO GET FANCY WITH TIMING...AND JUST GO CHC TUE NIGHT...AND MAINTAIN POP CATEGORIES WHERE THEY ARE FOR WED. .BGM...NONE. CEMPA ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 940 PM EST SUN DEC 22 2002 CONTINUITY LOOKS GOOD AT THIS POINT AS LAKE EFFECT ACTIVITY IS FOLLOWING THE FORECAST TO A TEE. THE MOST IMPRESSIVE ACTIVITY BY FAR IS POURING OFF LAKE ONTARIO INTO OSWEGO COUNTY AT THE MOMENT...WHILE NUISANCE FLURRIES AND -SHSN OFF LK ERIE ARE JUST NOW MAKING SOME NOISE ON THE KBUF RADAR. OFF LK ONTARIO...A LOW SHEAR 270 FLOW HAS GENERATED A FAIRLY WELL ORGANIZED AREA OF LES OVER OSWEGO AND SRN LEWIS COUNTIES. LATEST RUN OF THE RUC10 SHOWS THE SOUTHWARD DRIFT THAT THIS ACTIVITY HAS UNDERGONE DURING THE PAST HOUR OR TWO...BUT MODEL THEN LIFTS ACTIVITY BACK TO THE NORTH OVER THE TUG. THIS IS WHERE MM5 AND EARLIER 12Z ETA MODELS ANCHOR THE ACTIVITY THROUGH THE OVERNIGHT AND MONDAY MORNING. THIS LOOKS REASONABLE GIVEN UPSTREAM IR SAT IMAGES WHICH INDICATE THE PROLONGED 270 FLOW. THE CURRENT AREA OF LES SHOULD FURTHER ORGANIZE AND BECOME AN IMPRESSIVE PLUME OF SNOW FOR THE OVERNIGHT AND EARLY MONDAY AM PERIOD WITH 1-3 INCH/HR ACCUM RATES. SNOWFALL AMOUNTS OF 6 TO 12 INCHES OVER OSWEGO AND SOUTHERN PARTS OF JEFFERSON AND LEWIS COUNTIES LOOKS VERY GOOD...AND AM IN COMPLETE AGREEMENT WITH MENTIONING THE POTENTIAL FOR 2 FEET OVER THE TUG. THIS PERSISTENT FLOW WITH OROGRAPHIC ENHANCEMENT CERTAINLY PUTS THAT AREA IN THE LOLLIPOP ZONE WHERE MAX ACCUMS SHOULD BE FOUND. OFF LK ERIE...THE LES WILL BE LIMITED BY A MORE SHEARED ENVIRONMENT AND SMALLER DELTA T'S. MODELS HAVE BEEN CONSISTENT WITH KEEPING THE LAKE ERIE ACTIVITY MORE MULTI-BAND IN NATURE...WHICH WILL ALSO KEEP ACCUMS DOWN. ADVISORIES SOUTH OF BUFFALO AND BATAVIA LOOK REASONABLE. .BUF...LAKE EFFECT SNOW ADVISORY OVN AND MON AM NYZ010-012-019-020 LAKE EFFECT SNOW WARNING OVN AND MONDAY NYZ006>008 RSH ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 310 PM EST SUN DEC 22 2002 THE ETA, MM5 AND 06Z RUC10 ARE IN AGREEMENT IN DEVELOPING LAKE SNOWS EAST OF THE GREAT LAKES TONIGHT. OFF LAKE ONTARIO THE ETA CONTINUES THE LAKE SNOWS THROUGH MONDAY INTO TUESDAY. AT LEAST 2 FEET ARE LIKELY IN THE PERSISTENT SNOWS OFF LAKE ONTARIO WITH TEMPERATURES A COUPLE DEGREES COLDER THAN THE LAST EVENT. OFF LAKE ERIE THE LAKE SNOWS DIMINISH ON MONDAY AND THEN REDEVELOP FOR AWHILE MONDAY NIGHT. WE HAVE FOLLOWED THIS GUIDANCE CLOSELY WITH THIS PACKAGE. ELSEWHERE IT LOOKS LIKE ONLY SCATTERED ROGUE SNOW SHOWERS EXCEPT FOR MAYBE SOME BLEEDING NORTH AND SOUTH OFF THE LAKE ERIE BAND. IT'S LOOKING A LITTLE BLEAK OUTSIDE OF LAKE SNOWS FOR A WHITE CHRISTMAS WITH THE ETA KEEPING THE SNOW TO THE SOUTH. THE GFS BACKS UP SOME SNOW OVER THE AREA, BUT IT APPEARS TO ASSOCIATED WITH A STRAY DEFORMATION AREA, AND WITH THE SURFACE LOW ALONG THE COAST WE DON'T HAVE MUCH CONFIDENCE IN ITS VERIFICATION. COLDER AIR CHRISTMAS DAY AND A WESTERLY FLOW COULD SPRAY SOME SNOW ELSEWHERE DURING THE DAY, BUT WE FEEL IT IS ONLY A CHANCE AT THIS TIME. THE BEST BET FOR SNOW IS THURSDAY AS AN UPPER TROUGH MOVES THROUGH, BUT AT THIS DISTANCE WE WILL ONLY CALL FOR CHANCE POPS. .BUF... LAKE EFFECT SNOW ADVISORY FOR TONIGHT AND MONDAY MORNING NY010-019-020 LAKE EFFECT SNOW WARNING FOR TONIGHT AND MONDAY NYZ006-007-008 APB ny COASTAL BEND FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 930 AM CST SUN DEC 22 2002 WEAK SURFACE BOUNDARY LOCATED IN THE NEARSHORE WATERS AT 15Z AND WILL REMAIN QUASI-STATIONARY TODAY. CRP/BRO VWP ALREADY SHOW DEEP LAYERED S/SE FLOW ESTABLISHED ABOVE THE VERY SHALLOW COOL LAYER AND IS WELL DEPICTED BY THE LATEST SATELLITE IMAGERY. BOUNDARY LAYER FORCING/ISENTROPIC UPGLIDE(SUFFICIENTLY LOW CONDENSATION PRESSURE DEFICITED PER RUC 290K)/RADAR TRENDS/MOTTLED CLOUD APPEARENCE PER SATELLITE IMAGERY ARGUES INSERTION OF DRIZZLE(ESPECIALLY EAST). WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 10AM. HOWEVER...HIGHER DEWPOINTS WILL BE ADVECTED ACROSS THE EASTERN CWA THIS AFTERNOON AS WINDS VEER EAST AND THIS SUPPORTS RETENTION OF AREAS FOG WITH PATCHY FOG MOSTLY ELSEWHERE. SOME TWEAKING OF TEMPERATURES WILL BE NEEDED...NUDGING THEM UP OVER THE COASTAL COUNTIES AND LOWERING THEM A TAD OVER THE WEST. WILL CHANGE CLOUD COVER TO CLOUDY EVERYWHERE. MARINE...WEAK BOUNDARY ALONG THE COAST THIS MORNING. WINDS OVER THE MARINE ZONES CURRENTLY OUT OF THE NORTHEAST AND EAST AT 5 TO 10 KNOTS WITH PATCHY FOG OVER BAYS. BOUNDARY PROGGED TO RETURN NORTH THIS AFTERNOON WITH EAST TO SOUTHEAST WINDS INCREASING AS THE LLJ STRENGTHENS. NO MAJORT CHANGES NEEDED AT THIS TIME TO LATEST FORECAST. .CRP...NONE. 85/78 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 205 AM MST MON DEC 23 2002 FORECAST CONCERNS ARE SNOWFALL AMOUNTS OVER THE FAR SOUTHWEST/SOUTHERN CWA AS A WINTER STORM HEADS TOWARDS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS. TODAY-TONIGHT...UPPER LOW OVER SOUTHERN BAJA REMAINS NEARLY STATIONARY WHILE INTENSIFYING THROUGH THE PERIOD. AT THE SURFACE... HIGH PRESSURE IN CONTROL WITH A CONTINUATION OF COOLER AIR FILTERING INTO THE AREA. QUESTION BECOMES PRECIP. BEST LOW LEVEL MOISTURE AND MID LEVEL FORCING REMAIN OVER THE SOUTHWEST/SOUTHERN PORTIONS OF THE CWA WITH DRIER AIR BECOMING MORE PREVALENT AS ONE GOES NORTHEAST. THESE FACTORS AND EJECTING DISTURBANCE FROM THE UPPER LOW WOULD FAVOR SNOWFALL OVER THE ABOVE MENTIONED AREA TODAY. FSL RUC II IN AGREEMENT WITH ETA/AVN/NGM IN PRODUCING MEASURABLE SNOW FROM ROUGHLY FLAGLER COLORADO SOUTHEAST TO SOUTHEAST TO THE MONUMENT ROCKS (SOUTHWEST GOVE COUNTY). HIGHEST AMOUNTS WILL BE OVER GREELEY AND WICHITA WHERE UP TO 3 INCHES IS POSSIBLE. AFTER DISCUSSIONS FROM KPUB/KDDC (THANKS) I WILL UP POPS TO LIKELY CATEGORY AND UPDATE AMOUNTS. AS JET ENERGY AND UPPER WAVES MOVE BY NEUTRAL OMEGA TAKE PLACE BUT QPF FROM AVN/ETA SUGGEST SMALL POPS OVER SOUTHWEST PORTION OF THE AREA TONIGHT. GIVEN THIS AREA ALSO UNDER BETTER LOW LEVEL MOISTURE AND SLIGHT DIVERGENCE AT 500 MB WILL GO ALONG WITH IT. TUESDAY-TUESDAY NIGHT...UPPER SYSTEM BREAKS APART DURING THIS TIME PERIOD AND MODEL LOW LEVEL MOISTURE/DOWNWARD OMEGA/QPF POINT TO A DRY FORECAST PERIOD. WEDNESDAY-THURSDAY NIGHT...UPPER FLOW NOT WELL HANDLED BUT APPEARS TO BE A BROAD WESTERLY FLOW ON WEDNESDAY WITH AN UPPER TROUGH PASSAGE THURSDAY. A FEW SURFACE TROUGHS WILL MOVE ACROSS THE AREA. THESE FEATURES ALONG WITH DOWNSLOPE WINDS AND MORE SUN POINT TO WARMER TEMPS. FRIDAY-FRIDAY NIGHT...SOME SHORTWAVE UPPER RIDGING AND SURFACE TROUGH POINT TO SOME MORE WARMING. SATURDAY-SUNDAY...LEFT GENERALLY AS IS. .GLD...NONE. DDT ks AREA FORECAST DISCUSSION...CORRECTION OF TIME. NATIONAL WEATHER SERVICE MARQUETTE MI 505 AM EST MON DEC 23 2002 MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS/HEADLINES. WV IMAGERY AND RUC ANALYSIS INDICATED ELONGATED MID/UPR LVL NRN STREAM CUTOFF LO CENTERED OVER NRN QUEBEC. STRONG SHRTWV/VORT WAS LOCATED UPSTREAM...JUST NW OF LK SUPERIOR. IR/WV LOOPS ALSO SHOWED AREA OF DEEPER MOISTURE AND ENHANCED TOPS HAD DESCENDED ACRS NW UPR MI. LOW LVL MOISTURE WAS ALSO PLENTIFUL UPSTREAM PER CWPL SNDG (MOIST ISOTHERMAL AT -16C TO 700 MB) AND REPORTS OF 3-5SM -SN EARLIER OVER NE MN AND AT CYQT. COMBINATION OF UPWARD MOTION WITH 700-300 QVECTOR CONV WITH DPVA AHEAD OF THE SHRTWV AND COLDER H8 TEMPS TO NEAR -16C (GIVING LK-H8 DELTA/T TO AROUND 19C) HAS BROUGHT NOTABLE INCREASE IN COVERAGE AND INTENSITY OF LES INTO NW UPR MI AND ERN LK SUPERIOR. HEAVIER SNOW BEGAN NEAR KCMX AT 07Z WITH VSBY FREQUENTLY DOWN TO NEAR 1/4SM WITH +SHSN AND HOUGHTON WEBCAMS ALSO SHOWED VSBY DOWN TO AROUND 1/2SM AT TIMES. KMQT 88D SHOWED 280-290 ALIGNED BANDS WITH CORES OF 28DBZ REFLECTIVITY OVER ERN LK SUPERIOR WITH BANDS APPEARING TO BRUSH THE SHORELINE E OF GRAND MARAIS. TODAY...00Z/06Z WAS SLIGHTLY SLOWER WITH MOVEMENT OF SHRTWV/VORT UPR MI THAN THE 00Z GFS WITH THE VORT AXIS INTO INTO NW UPR MI AT 18Z WHILE THE GFS PLACES IT OVER SE UPR MI. GIVEN RECENT TRENDS...SLOWER ETA PREFERRED WHICH IS ALSO SUPPORTED BY THE 06Z RUC.SO...EXPECT LCLY HEAVY LES TO CONTINUE OVER NW UPR MI TIL THIS AFTERNOON WHEN DNVA/SUBSIDENCE TAKES OVER WITH LOWER INVERSION HGTS AND ASSOCIATED WARMING OF H8 TEMPS TO AROUND 13C. SNOWFALL RATES UP TO 1 INCH/HR SHOULD CONTINUE WITH ADDITIONAL ACCUMULATIONS OF UP TO 6 INCHES. ETA 950 MB WIND FCST DEPICTS SLOW VEERING TREND WITH WEAKENING CONVERGENCE ZONE SHIFTING GRADUALLY SOUTH FROM KCMX AFT 12Z TOWARD NE ONTONAGONA AND CNTRL HOUGHTON COUNTY. SHIFT TOWARD 300 WIND WILL ALSO SHORTEN FETCH INTO MOST OF THE KEWEENAW. HOWEVER...CONTINUED LIFT AHEAD OF THE SHRTWV ALONG WITH LOW LVL MOISTURE UPSTREAM WILL KEEP ACCUMULATING LES GOING.SO...WL LEAVE LES WARNING HEADLINE IN PLACE THROUGH THIS MORNING. OVER THE EAST...ETA LINES UP WELL WITH CURRENT TRENDS AND IS CONSISTENT IN KEEPING 950 MB CONVERGENCE ZONE ACRS FAR ERN ALGER (NEAR GRAND MARAIS) TO NRN LUCE COUNTY THROUGH 18Z. AFT 18Z...WINDS VEER ENOUGH FOR SOME LES TO REACH KERY. HOWEVER...SYNOPTIC SUPPORT FROM SHRTWV WILL BE DEPARTING/WEAKENING BY THIS TIME. SO...EXPECT SHARP GRADIENT TO HEAVIER SNOW OVER NRN PORTION OF LUCE COUNTY AND FAR NRN SCHOOLCRAFT COUNTY. AGAIN LES WARNING HEADLINE MAINTAINED INTO THIS AFTERNOON AS LATER EXIT OF THE SHRTWV AND LONGER FETCH KEEP HEAVIER LES GOING WELL INTO THE AFTERNOON OVER THE NE CWA. OVER THE REST OF UPR MI...EXPECT THAT SCT -SHSN WILL DIMINISH BY AFTERNOON AS THE SHRTWV MOVES THROUGH WITH ACCUMULATIONS AMOUNTING TO NO MORE THAN A HALF INCH. CAA SHOULD COUNTER DIURNAL TREND WITH HIGHS NOT NEAR EARLY MORNING READINGS. JLB THE SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA THIS EVENING. LATER TONIGHT...ANOTHER WEAK SHORTWAVE WILL SLIDE ACROSS NORTHERN WISCONSIN. UPPER LEVEL JET WILL REMAIN JUST SOUTH OF THE FORECAST AREA AND WILL HAVE VERY LITTLE AFFECT ON THE FORECAST AREA. A THERMAL RIDGE WILL MOVE INTO NORTHERN PLAINS AND WILL LOWER THE DELTA-T'S ACROSS LAKE SUPERIOR OVERNIGHT. THE SURFACE RIDGE WILL INTENSIFY OVER THE NORTHERN PLAINS. ANTI-CYCLONIC FLOW WILL KEEP THE WINDS OVER LAKE SUPERIOR OUT OF THE NORTHWEST. LOW LEVEL Q-VECTOR CONVERGENCE WILL INCREASE OVER CENTRAL LAKE SUPERIOR OVERNIGHT. THIS WILL KEEP LAKE EFFECT SNOWS GOING. WARM AIR ADVECTION AT 850MB WILL LOWER THE INVERSION OVER LAKE SUPERIOR TO AROUND 900MB. CONDITION FAVORABLE FOR LAKE EFFECT SNOWS TO CONTINUE...BUT WILL NOT PRODUCE SIGNIFICANT ACCUMULATION. A CLOSED LOW WILL MOVE TO EAST CENTRAL QUEBEC ON TUESDAY. A BROAD RIDGE WILL SHIFT OUT OF THE CANADIAN ROCKIES INTO THE WESTERN CANADIAN PRAIRIES. AS A WEAK SHORTWAVE MOVE ACROSS THE FORECAST AREA TUESDAY MORNING...ANOTHER MUCH WEAKER SHORTWAVE WILL SLIDE DOWN THE LEE OF THE CANADIAN ROCKY'S RIDGE AND REACH NORTHWEST ONTARIO BY 12Z TUE. AS A COLD FRONT SWINGS INTO NORTHERN ATLANTIC STATES... ANOTHER COLD FRONT WILL FOLLOW THE FIRST THROUGH NORTHERN ONTARIO. A BROAD SURFACE RIDGES WILL MOVE INTO THE CENTRAL AND NORTHERN PLAINS. 850MB TEMPERATURES ON TUESDAY WILL LOWER TO -10C...GIVING A LAKE-850MB DELTA-T'S OF 13C. LOW LEVEL MOISTURE BELOW 850MB WILL BE 90 PERCENT OR HIGHER ON TUESDAY. ANTI-CYCLONIC FLOW AROUND THE RIDGE WILL KEEP THE SURFACE WIND MAINLY OUT OF THE NORTHWEST ON TUESDAY. THESE CONDITIONS ARE FAVORABLE FOR LAKE EFFECT SNOW TO CONTINUE OVER NORTHERN U.P...MAINLY OVER THE KEWEENAW PENINSULA AND BETWEEN MUNISING AND WHITEFISH POINT. Q-VECTOR CONVERGENCE WILL BE THE STRONGEST IN THE MORNING OVER CENTRAL LAKE SUPERIOR...BUT WILL WEAKEN THROUGH THE DAY. TUESDAY NIGHT WILL SEE DRIER AIR MOVING INTO THE FORECAST AREA. WARM AIR ADVECTION OUT OF THE CENTRAL PLAINS WILL BRING UP THE 850 MB TEMPERATURES. A WEAK SHORTWAVE WILL SWING ACROSS THE FORECAST AREA. LOW LEVEL Q-VECTOR ANALYSIS FAVOR MAINLY DIVERGENCE ACROSS THE AREA TUESDAY NIGHT. WINDS WILL REMAIN OUT OF THE NORTHWEST...AND START TO BACK WEST. THE WINDS WILL BACK WEST ON WEDNESDAY. DELTA-T'S WILL DECREASE TO 8C OVER THE WEST AND 11C OVER THE EAST. LOW LEVEL RELATIVE HUMIDITY WILL BE AROUND 65 PERCENT. A WEAK SHORTWAVE WILL MOVE ACROSS THE AREA ON WEDNESDAY. CONDITIONS WILL STILL BE FAVORABLE FOR LAKE EFFECT SNOW TO CONTINUE BUT WILL BE LIGHT AND SCATTERED. 280K ISENTROPIC ANALYSIS SHOWING WEAK ASCENT ACROSS THE AREA ON WEDNESDAY. WILL KEEP A MENTION OF LAKE EFFECT GOING INTO EARLY WEDNESDAY NIGHT. A THERMAL RIDGE WILL EXPAND OUT OF THE NORTHERN PLAINS INTO THE UPPER GREAT LAKES ON THURSDAY. WARM ADVECTION WILL LOWER THE INVERSION TO 950MB AND WINDS WILL BACK SOUTHWEST. DELTA-T'S WILL LOWER TO 10C ACROSS THE LAKE. THIS SHOULD END LAKE EFFECT ACROSS THE FORECAST AREA. .MQT...LES WRNG MIZ006-007-085 THROUGH TODAY. LES WRNG MIZ001>003-084 THROUGH THIS MORNING. GALE WARNING E LK SUPERIOR. DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 302 AM EST MON DEC 23 2002 ... SNOWSTORM FOR CHRISTMAS ??? ... TWO PRIMARY CONCERNS FOR THIS FORECAST CYCLE. FIRST IS WHAT HAPPENS THE OUR FEEBLE LAKE EFFECT EVENT CURRENTLY UNDERWAY? THEN NEXT QUESTION IS JUST HOW FAR NORTH DOES THAT SOUTHERN STREAM SYSTEM GET CHRISTMAS EVE? CURRENTLY A MODERATED SHORTWAVE IS PASSING OVER SOUTHERN LOWER MICHIGAN. THE VAD WIND PROFILE SHOWS INVERSION HEIGHTS TO 10000 FT. THE RUC AND ETA SUGGEST THE 1000/850 RH REMAIN NEAR 90 PCT TILL 12Z. WHILE THAT IS GOING ON... WE HAVE THE 850 MB -12C ISOTHERM MOVING ACROSS LAKE MICHIGAN WITH 1000/850 MEAN WIND (VAD) 270/35KTS. NORMALLY WITH LAKE TO 850 TEMP DIFFERENCE NEAR 15C... THE 1000/850 RH NEAR 90 PCT AND THE -12 WELL INTO THE CLOUD DECK WE WOULD HAVE A DECENT LAKE EFFECT SNOW EVENT UNDERWAY. HOWEVER... THERE IS THE MATTER OF THAT 140 TO 150 KNOT JET SEGMENT PASSING BY JUST TO OUR SOUTH THIS MORNING. THE LEFT ENTRANCE REGION HAS A SIGNIFICANT AMOUNT OF SINKING AIR ASSOCIATED WITH IT. EVIDENCE OF THAT CAN BE SEEN ON THE IR AND WATER VAPOR LOOPS WITH DRYING AIR OVER SOUTHWEST LAKE MICHIGAN. THIS IS PICK UP BY BOTH THE RUC AND ETA SINCE THEY BOTH SHOW DRYING AIR OVER SOUTHWEST LAKE MICHIGAN THAT DOES MOVE INTO SOUTHWEST MICHIGAN TOWARD MORNING. BOTTOM LINE TO THIS IS ONCE THE SHORTWAVE GETS THROUGH BY 12Z INVERSION HEIGHTS CRASH TO NEAR 3000 FT BY 18Z. THE -12C IS NO LONGER IN THE CLOUDS EITHER. SO I SEE THE SNOW SHOWERS (MOSTLY N OF INTERSTATE 96) DIMINISHING QUICKLY TO FLURRIES BY LATE MORNING. I WILL HAVE FLURRIES IN THE FORECAST ACROSS THE CWA THIS AFTERNOON. THE INVERSION NEAR 3000 FT SEEMS FAIRLY STRONG AND WITH WEST WINDS... AND LAKE TO 850 TEMP DIFFERENCES STILL NEAR 14C AT 00Z TONIGHT... CLOUDS WILL REMAIN. IT SHOULD BE NOTED TOO THAT THE 1000/925 THICKNESS VALUES FALL THROUGH THE DAY TODAY AND THROUGH TONIGHT (COLD AIR CONTINUES TO COME IN AT LOW LEVEL WHILE WARMING STARTS ABOVE 925 MB AFTER 12Z). IN ANY EVENT WHAT EVEN ACCUMULATIONS THERE WILL BE TODAY WILL BE AN INCH OR LESS (MOST THOUGH 15Z AND THEN NORTH OF MKG). TONIGHT THE COLD AIR POOL PULLS OUT AS THE SOUTHERN STREAM SYSTEMS HEADS TOWARD THE SOUTHERN PLAINS. THAT PUSHES THAT STRONG JET CORE NORTH ACROSS LOWER MICHIGAN. ONCE THAT HAPPENS... THE TEMPS BETWEEN 950 AND 700 MB WARM AND WARM BY FAR AND AWAY TO MUCH OF ANY LAKE EFFECT SNOW SHOWERS. SINCE IT REMAINS COLD ENOUGH FOR LAKE SNOW SHOWERS THROUGH 06Z TUESDAY...I WILL KEEP FLURRIES GOING OVERNIGHT. ON TUESDAY... SURFACE RIDGING BUILDS IN BETWEEN THE EXITING NORTHERN STREAM SYSTEM AND THE DEVELOPING SOUTHERN STREAM SYSTEM. SOUTHWEST MICHIGAN IS IN A "COL". WITH INVERSION HEIGHT LOW (BEING ON THE SOUTH SIDE OF THE POLAR JET BY THEN) AND 850 AND 925 TEMPERATURES TO WARM FOR LAKE EFFECT... BUT THE 1000/925 RH AVERAGING NEARLY 85 PCT THROUGH MOST OF TUESDAY... I WILL GO WITH A STRAIGHT MOSTLY CLOUDY FORECAST. AS FOR THE SOUTHERN STREAM SYSTEM... THE MODELS HAVE ALL TRENDED FARTHER NORTH WITH THE TRACK OF THIS SYSTEM. SINCE THE MODELS TYPICALLY OPEN UP SOUTHERN STEAMS UPPER WAVES TO FAST... AND SINCE THIS SYSTEM ALREADY HAS THUNDERSTORMS OVER THE SOUTHWEST U.S. AT NIGHT... I BELIEVE IT WOULD NOT BE A STRETCH TO BELIEVE THE SYSTEM WILL END UP FARTHER NORTH THAN ANY OF THE MODELS ARE FORECASTING (ENSEMBLES OR NO ENSEMBLES). CURRENTLY THE ETA IS THE MOST NORTH AND STRONGEST WITH THE UPPER LOW... IT ALMOST KEEPS A CLOSED UPPER LOW... IT SEEMS BETTER TO ME TO PUT A LOW CHC POP IN THE FORECAST FOR THE SOUTHERN 1/2 OF THE CWA CHRISTMAS EVE. WE WILL HAVE TO WATCH LATER MODEL RUNS TO SEE IF THE TREND CONTINUES. THE OTHER ISSUE WITH THIS SYSTEM IS HOW FAST DOES THE ENERGY FROM THIS SYSTEM TRANSFER FROM THE PRIMARY SYSTEM TO THE SECONDARY OVER THE EAST COAST? CAN NOT ANSWERS THESE QUESTION JUST YET. NOTE... SINCE NORTH WINDS RESULT IN DOWNSLOPE LOW LEVEL WINDS OVER SOUTHWEST MICHIGAN...AND SINCE THERE WILL BE A LOT OF SINNING AIR ON THE NORTH SIDE OF THE SYSTEMS PRECIPITATION AREA... IT IS QUESTIONABLE THAT THERE WILL BE ANY SNOW SHOWERS OVER CENTRAL AND NORTHERN LOWER MICHIGAN TUESDAY NIGHT. EVEN SO... FOR NOW... SINCE THE TRACK OF THIS SYSTEM IS NOT CARVED IN STONE... I WILL KEEP A CHANCE GOING THERE TOO. THANKS FOR THE COORDINATION DTX (RAY). ZONES BY 415 AM. BILL EXTENDED FORECAST DISCUSSION... AS FAR AS THE EXTENDED PERIODS ARE CONCERNED...MODELS ARE IN FAIRLY GOOD AGREEMENT FOR THIS PACKAGE. AS THE DEVELOPING STORM SYSTEM FROM TUE MOVES EAST AND AFFECTS THE NORTHEAST CONUS ON WED...LOW LEVEL FLOW WILL BACK TO THE NORTHWEST ACROSS THE CWA. WITH THE LOW LEVEL NW FLOW...COLD AIR WILL MOVE IN ACROSS THE CWA. H850 TEMPS ARE PROGGED TO FALL TO -11 TO -13C ON WED. THIS...IN COMBINATION WITH LAKE MICHIGAN TEMPS AROUND 5C WILL PRODUCE DELTA T/S IN THE MID TO UPPER TEENS. RH X-SECTIONS SHOW A DECENT AMOUNT OF MOISTURE AROUND... ESPECIALLY AT AND ABOVE THE -10C ISOTHERM. WILL CONTINUE WITH LAKE EFFECT SHSN FOR CHRISTMAS DAY. THIS BOUT OF LAKE EFFECT LOOKS TO BE SHORT LIVED THOUGH AS WAA FROM THE WEST WILL HELP SHUT OFF ANY LAKE EFFECT SHSN EARLY THU. WILL KEEP THE CLOUDS IN THOUGH THROUGH THE DAY AS TEMPS ARE NOT EXPECTED TO WARM UP ENOUGH TO DISSIPATE THE CLOUDS. AS A SFC AREA OF HIGH PRESSURE REMAINS TO OUR SOUTH THROUGH FRI...WESTERLY LOW LEVEL FLOW WILL CONTINUE TO BRING IN WEAK WAA. WITH THE PROXIMITY OF THE HIGH AND WAA...WILL KEEP THE PARTLY CLOUDY GOING FOR FRI. IT LOOKS LIKE ATTM...EVEN EARLY SAT COULD BE NICE AHEAD OF THE NEXT SYSTEM. AS A WEAKENING TROUGH/COLD FRONT APPROACHES LATE SAT...WE COULD SEE SOME PCPN. LOOKING AT THICKNESSES AND LOW LEVEL TEMPS...PCPN LOOKS TO BE MIXED RAIN AND SNOW. WILL ADJUST THIS THINKING TO THE LATE SAT/SUN TIME FRAMES. NJJ .GRR...NONE. mi SOUTH PLAINS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 345 AM CST MON 23 DEC 2002 MODELS DO NOT APPEAR TO HAVE A GOOD HANDLE ON THIS UPPER LOW. WATER VAPOR IMAGERY INDICATES THAT THIS IS STILL A CLOSED SYSTEM. WITH LACK OF DATA FROM NORTHERN MEXICO BELIEVE THE MODELS ARE WEAKENING THE LOW WAY TOO FAST. OF CONCERN IS THE DRY AIR THAT IS MOVING INTO THE BIG BEND IN THE WAKE OF THE WARM CONVEYOR BELT THAT IS COMBINING WITH LOWER LEVEL ISENTROPIC LIFT TO ASSIST IN THE OVERRUNNING CONVECTION THAT IS LOCATED OVER THE EASTERN 1/3RD OF THE CWA. 06Z RUC MODEL APPEARS TO HAVE A DECENT HANDLE ON AT LEAST THROUGH NOON. USING THE AXIS OF THE 850MB LOW POSITION FOR THE TRANSITION OF PRECIPITATION ACROSS THE AREA WILL LIKELY WORK FAIRLY WELL. SNOW ALREADY OCCURRING ACROSS PARMER AND BAILEY COUNTIES WITH ACCUMULATIONS ON SOME ROADWAYS. PRECIPITATION IS A MIX OF SNOW AND SLEET FURTHER SOUTH...MAYBE EVEN A LITTLE FREEZING RAIN FROM PLAINS TO FLOYDADA TO EAST OF SILVERTON. BELIEVE THAT USING THE BACKSIDE OF THE 85H LOW ON THE RUC WILL BE A GOOD TRANSITION LINE FOR THE PRECIPITATION FORM MIXED TO SNOW. AT LAST GLANCE WITH A LITTLE BIT OF EVAPORATIONAL COOLING IN THE LOWER LEVELS WILL BUMP THE CHANGEOVER UP JUST SLIGHTLY ACROSS THE CENTRAL AND EASTERN SOUTH PLAINS. BELIEVE THE CHANGE TO ALL SNOW ACROSS THE SOUTHEAST ZONES WILL LINGER INTO THE AFTERNOON. NOW AS FAR AS AMOUNTS GO BEST ESTIMATES WOULD INDICATE 6-10 INCHES OF SNOW ACROSS THE NORTHERN 2 ROWS FROM BRISCOE AND FLOYD COUNTY WESTWARD TO THE TEXAS/NEW MEXICO BORDER. NORTHEAST ZONES WILL CHANGE TO SNOW A LITTLE LATER BUT BELIEVE 4+ IS STILL A GOOD BET. FOR THE SOUTHERN 2 ROWS WEST OF THE CAPROCK WE SHOULD SEE ACCUMULATIONS BUT AMOUNTS ARE DIFFICULT WITH THE UNCERTAINTY OF THE TRANSITION. USING THE RUC WE WILL CHANGE THIS AREA OVER TO SNOW BY 16Z WITH 2 TO 4 INCHES OF SNOWFALL POSSIBLE. BELIEVE SOUTHEASTERN AREAS WILL BE A LATE CHANGE TO SNOW SO WILL GO WITH NO HIGH-LITES THERE FOR NOW. ONLY MENTION UP TO 1 INCH OF SNOW. BELIEVE THE SNOW WILL LAST LONG ENOUGH TO COVER BOTH TODAY AND A DECENT PORTION OF THE TONIGHT PERIOD. SO WILL ISSUE THE WARNING AND ADVISORY THROUGH 12Z TUESDAY. HIGH TEMPERATURES TODAY HAVE MOST LIKELY BEEN REACHED. EXPECT STEADY TO SLOWLY FALLING TEMPS TODAY. FOR THE REMAINDER OF THIS PACKAGE IT APPEARS ANOTHER FAST MOVING TROUGH WILL MOVE ACROSS THE CWA WEDNESDAY INTO THURSDAY. SLIGHT CHANCE OF RAIN/SNOW LOOKS GOOD. OTHERWISE WILL KEEP TEMPS A LITTLE COOLER THAN GUIDANCE THROUGH AT LEAST THURSDAY WITH EXPECTED SNOW COVER AND MOST LIKELY LINGERING CLOUD COVER OVER THE SNOW. MM FRIONA 28 21 29 18 / 100 80 20 00 TULIA 30 21 31 19 / 100 80 20 00 LUBBOCK 35 24 32 21 / 100 80 20 00 BROWNFIELD 36 24 33 22 / 100 80 20 00 CHILDRESS 37 25 33 21 / 100 80 30 00 ASPERMONT 41 28 37 24 / 100 80 30 00 .LUB...HEAVY SNOW WARNING TXZ21>32 THROUGH TONIGHT. WINTER WEATHER ADVISORY TXZ33>36-39>41 FOR TODAY. tx SOUTH CENTRAL TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 315 AM CST MON DEC 23 2002 ONE OF THE MORE SIGNIFICANT TORNADO/SEVERE WEATHER THREATS OF THE YEAR FOR SOUTH CENTRAL TEXAS COMES TWO DAYS BEFORE CHRISTMAS. THE WESTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS CAN EXPECT A WET MORNING WITH ISOLATED SEVERE STORMS TO CREATE A SHOPPING HAZARD. A MORE OMINOUS THREAT EXISTS EAST OF THE I-35 CORRIDOR WHERE DAYTIME HEATING WILL ENHANCE THE SEVERE WEATHER THREAT INTO A THEAT FOR SUPERCELLS AND TORNADOES. IF IT WERE NOT FOR THE MORNING STREAMER CELL SPEEDS OF AROUND 30 TO 35 MPH, WOULD BE CONCERNED OF A FLASH FLOOD THREAT. SOILS REMAIN NEARLY SATURATED FROM PREVIOUS RAINS, BUT WITH PRECIPITABLE WATER VALUES HOLDING BELOW 1.5 FOR THE MOST PART, EXPECT ONLY THREAT OF SUSTAINED HEAVY RAINS TO BE IN THE PATHS OF ANY SUPERCELLS THAT DEVELOP OVER THE SOUTHEASTERN COUNTIES LATER TODAY. WILL MENTION LOCALLY HEAVY RAINFALL FOR THE EASTERN TWO-THIRDS WITH SEVERE WORDING MENTIONED AREA-WIDE. WITH 06Z SATELLITE TRENDS SHOWING A SLIGHT EASTWARD POSITION OF THE UPPER LOW CENTER COMPARED TO FORECAST AND A PAIRED JET PATTERN INDICATING DEEPENING OVER CENTRAL TEXAS FOR THE NEXT 12 HOURS, THE QPF TRENDS WILL PROBABLY BE A BIT AHEAD OF THE ALREADY FASTER GFS. RAINFALL INTENSITIES ARE STEADILY INCREASING IN RESPONSE TO THE LOW LEVEL JET OVER THE CENTRAL COUNTIES. WITH A NEAR SOLID AREA OF RAIN EXPECTED OVER THE CENTRAL PORTIONS HALF OF THE FORECAST AREA BY AROUND DAYBREAK, WILL CALL FOR HIGH POPS OF 80 TO 100 PERCENT OVER THE EASTERN TWO-THIRDS. HELICITIES COULD APPROACH 500 M2S2 OVER THE SOUTHEASTERN COUNTIES TOWARD NOON ACCORDING TO THE RUC; WITH 1500 J/KG OR GREATER CAPES, THE THREAT FOR SEVERE WEATHER AND TORNADOES NEEDS TO BE WORDED STRONGLY HERE. FOR WESTERN SECTIONS, WILL KEEP POPS IN THE 50-60 PERCENT RANGE WITH SEVERE WORDING THROUGH THE AFTERNOON. DAYTIME HEATING COULD TRIGGER A FEW HAILSTORMS DESPITE A GOOD DRY PUNCH ENTERING WEST TX. WITH THE FASTER SPEED, WILL PLAN ON LESS MOISTURE BEING AVAILABLE WHEN THE BASE OF THE TROUGH LIFTS ACROSS THE FORECAST AREA TUESDAY. WILL TRIM POPS TO A SLIGHT CHANCE NORTHEAST. OTHERWISE A WARM AND DRY ZONAL PATTERN WILL RESUME AGAIN FOR THE NEXT SEVERAL DAYS UNTIL THE GFS AND NOGAPS DEPICT ANOTHER VIGOROUS STORM SYSTEM THREATENING THE SOUTHERN PLAINS EARLY NEXT WEEK. A WEAK SHORTWAVE MOVES THROUGH MAINLY NORTH TEXAS THURSDAY, BUT THE AIR SHOULD BE TOO DRY TO SUPPORT MEASURABLE RAINS OVER SOUTH CENTRAL TEXAS. PRELIMINARY NUMBERS... AUS 066/041/052/030/057 +5200 DRT 071/043/056/034/061 52-00 SAT 071/042/057/035/059 +4-00 .EWX...NONE. 18/3/PM tx INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE HANFORD CA 330 AM PST MON DEC 23 2002 STRATUS AND FOG...ALONG WITH FROST...IS THE MAIN CONCERN THIS MORNING AND THROUGH PARTS OF TODAY. AS OF 300 AM...VALLEY TEMPERATURES WERE RANGING FROM 32 TO 39. THE FOG HAS BEEN VERY PATCHY AND MOSTLY EAST OF HIGHWAYS 99 AND 43. YET...VISIBILITIES HAVE REMAINED ABOVE A QUARTER MILE IN MOST LOCATIONS WITH THE HANFORD/VISALIA AREA IN THE WORST PART OF THE FOG. RUC ANALYSIS COMBINED WITH IR SATELLITE IMAGERY SHOWS THE UPPER LOW NOW PUSHING THROUGH THE DESERT SOUTHWEST. OVER THE WEST COAST...THE DEVELOPING RIDGE IS PUTTING THE CWFA UNDER A DRY NORTHERLY FLOW. THIS PATTERN WILL SUPPORT THE REDEVELOPMENT OF FOG AND FROST MONDAY NIGHT BEFORE THE INTRODUCTION OF THE NEXT STORM SYSTEM. MODELS CONTINUE THEIR GOOD AGREEMENT WITH TIMING THE NEXT PACIFIC STORM INTO THE CENTRAL VALLEY TUESDAY AFTERNOON. WHILE NOT AS STRONG AS THE PREVIOUS STORM...WILL EXPECT RAIN AND SNOW OVER THE DISTRICT FOR A SHORT DURATION OF TIME. A RATHER STRONG JET STREAM WILL DRIVE THE STORM THROUGH THE AREA QUICKLY ALLOWING THE DISTRICT TO DRY OUT CHRISTMAS DAY. YET...ANOTHER STORM BEHIND THE FIRST WILL RE-INTRODUCE PRECIP OVER THE DISTRICT LATER WEDNESDAY INTO THURSDAY. WITH A STRONG JET ON TUESDAY STORM...QPF WILL REMAIN LIGHT AND BELOW ADVISORY CRITERIA. THE SECOND STORM LOOKS MORE IMPRESSIVE WITH BETTER POSSIBLE PRECIP TOTALS. MOLINA IN THE EXTENDED...WILL CONTINUE TO LEAN TO THE WETTER SOLUTIONS THAT INDICATE PERSISTENCE OF STORMY PATTERN. GFS PROGS THE NEXT SYSTEM TO BE A WET ONE FOR LATER THURS/FRI. FOR THE WEEKEND...NO ONE MODEL TO HANG A HAT ON. GFS TRYING TO BUILD A RIDGE ALONG THE WEST COAST BY SUN...THE UKMET BUILDS IT SAT...BUT EURO AND GEM KEEP THINGS MORE UNSETTLED IN FAST ZONAL FLOW. IN KEEPING WITH PERSISTENCE...WILL FOLLOW THE FLATTER FASTER EURO SOLUTION FOR NOW...AND JUST BROADBRUSH CHANCE OF PRECIP SAT/SUN. NOT MUCH CONFIDENCE DAYS 6-7. BINGHAM .HNX...NONE. ca WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN 934 AM EST MON DEC 23 2002 MORNING RAOB DATA SHOWS INCREASING LOW LEVEL MOISTURE BELOW A STRONG SUBSIDENCE INVERSION ~850MB...SO EXPECT TO SEE A FEW MORE CLOUDS DEVELOP ACROSS THE FA DURING THE AFTERNOON. DEVELOPING EAST-SOUTHEAST WIND FLOW AROUND THE SURFACE HIGH MOVING OFF THE SE U.S. COAST WILL ALLOW TEMPERATURES TO CLIMB TO ABOVE SEASONAL LEVELS (MID/UPPER 70S) THROUGHOUT WITH INCREASING DEW POINTS. ONGOING ZONES COVER ALL OF THIS...SO NO MORNING UPDATE PLANNED. MARINE...C-MAN AND OFFSHORE BUOY TRENDS AS WELL AS THE LATEST RUC GUIDANCE SUPPORTS THE ONGOING PACKAGE FOR THE AFTERNOON...SO NO CHANGES EXPECTED IN THE 1030 AM UPDATE. .TBW...NONE. MCMICHAEL fl SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1020 AM EST MON DEC 23 2002 LATEST RUC AND 88D ANALYSIS SHOWS AN ENHANCED CONVERGENCE SETTING UP ALONG I69. 1000-850 WINDS REMAIN FROM THE WEST NEAR 30 KTS WITH 850 TEMPS STILL -10 TO -12...DELTA T/S RIGHT AROUND 13C. INVERSION HEIGHTS FROM SURROUNDING UPPER AIR SIGHTS ARE NEAR 850 MBS BUT WELL WITHIN A GOOD ICE NUCLEATION PARAMETERS. WE WILL UPGRADE THIS REGION TO OCCASIONAL SNOW WITH ACCUMULATIONS LESS THAN 1 INCH. AS SHORT WAVE AND COLD FRONT MOVE DOWN ACROSS NORTHERN LOWER THIS AFTERNOON...WE SLOWLY WARM UP 850 TEMPS AND DECREASE AVAILABLE MOISTURE ACROSS THE LAKE...TO REDUCE SNOW BACK TO FLURRIES PER NEW RUC GUIDANCE. OTHERWISE NO OTHER CHANGES AT THIS TIME. LOTS OF TALK ABOUT TOMORROWS SNOW EVENT...LATEST 12Z ETA IS A LITTLE FURTHER NORTH WITH RESPECT TO SFC LOW TRACK ALTHOUGH UPPER LEVELS DO NOT SUPPORT POSITION. WITH THESE POSITIVE TILTED TROFS...IT WOULD BE DIFFICULT TO HAVE THESE SYSTEMS COME THIS FAR NORTH. WE WILL AWAIT FOR THE GFS BEFORE MAKING DECISIONS. ZFP AND GRIDS ON THE STREET. .DTX...GALE WARNING...TODAY...ALL OF LAKE HURON. BGM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 925 AM EST MON DEC 23 2002 BASED ON CURRENT CONDITIONS AND THE LATEST RUC WILL UPDATE ZONES AND CHANGE TODAY/S WINDS TO LIGHT AND VARIABLE. NO OTHER CHANGES PLANNED. FCSTID = 5 CAE 64 42 54 48 / 0 50 100 50 AGS 64 43 58 48 / 0 60 100 50 SSC 64 42 55 48 / 0 50 100 50 OGB 64 43 58 48 / 0 50 100 50 .CAE... GA...NONE. SC...NONE. RJL THE FOLLOWING IS THE PREVIOUS FORECAST DISCUSSION. ************************************************************** AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 308 AM EST MON DEC 23 2002 POTENTIAL FOR SIGNIFICANT RAIN EVENT ACROSS SOUTH CAROLINA TUE. GFS SHOWING BETTER RUN-RUN CONSISTENCY THAN ETA/NGM. INTENSE UPPER LOW OVER THE SOUTHWESTERN STATES FORECAST TO MOVE EAST. PLUME OF UPPER LEVEL MOISTURE SEEN ON WATER VAPOR SPREADING NORTHEAST INTO THE PLAINS STATES. FOR TODAY ACROSS THE SOUTHEAST...JUST SOME HIGH LEVEL CI EXPECTED...INCREASING THIS AFTERNOON AS UPPER FLOW BECOMES SOUTHWEST. WILL GO MOSTLY SUNNY. CLOUDS THICKENING OVERNIGHT. WARM FRONT SETTING UP ACROSS GULF COAST REGION. 290-300K ISENTROPIC LIFT DEVELOPING AFTER MIDNIGHT. EVEN ETA MODEL SHOWING MODERATE LIFT TOWARD MORNING...ESPECIALLY IN THE CSRA. HOWEVER...LOW LEVELS WILL BE DRY EARLY AND ANY RAIN WILL BE LIGHT UNTIL DAYBREAK. WILL INCREASE POP TO LIKELY AGS AREA AND CONTINUE CHANCE REST OF CWA. STRONG UPPER LEVEL DIVERGENCE EXPECTED TUE MORNING WITH 250 MB ENTRANCE REGION OF JET ACROSS AREA. STRONG 850MB WARM AIR ADVECTION/ISENTROPIC LIFT...LOW LEVEL JET AROUND 40KT. WILL GO CATEGORICAL. MODEL QPF/HPC RATHER HIGH IN THE MIDLANDS...WILL MENTION HEAVY RAIN POSSIBLE. AVN INDICATING IN-SITU WEDGE SETTING UP...AS SURFACE LOW MOVES FROM MS TO THE CAROLINA MOUNTAINS. SECONDARY LOW DEVELOPMENT OFF THE COAST. EXPECT COOLER AIR MASS IN NORTH CAROLINA TO SPREAD SOUTH INTO MIDLANDS/CSRA. WARM FRONT JUST SOUTH OF AGS IN THE AFTERNOON...MAY TRY TO MOVE NORTH. WILL FORECAST HIGH TEMPS IN THE 50S. LOW MOVES NORTHEAST TUE NIGHT...LIFT AND MOISTURE FLUX OFF THE COAST. DRIER AIR ADVECTING INTO AREA AFTER 00Z...WITH COLD AIR ADVECTION DEVELOPING AFTER MIDNIGHT. WILL KEEP CHANCE POPS UNTIL AROUND MIDNIGHT. WED...LOOKS BREEZY AND COOL...PUT WILL DROP POPS. TEMP FORECAST...NEAR LOCAL CONSENSUS...EXCEPT COOLER TUE. FCSTID = 19 CAE 64 42 54 48 / 0 50 100 50 AGS 64 43 58 48 / 0 60 100 50 SSC 64 42 55 48 / 0 50 100 50 OGB 64 43 58 48 / 0 50 100 50 .CAE... GA...NONE. SC...NONE. AWP sc SOUTH CENTRAL TEXAS FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 10 AM CST MON DEC 23 2002 SENT QUICK UPDATE TO ZONE PACKAGE FOR TORNADO WATCH # 798 WHICH REPLACES #797. MORE LATER. 06/08 ONE OF THE MORE SIGNIFICANT TORNADO/SEVERE WEATHER THREATS OF THE YEAR FOR SOUTH CENTRAL TEXAS COMES TWO DAYS BEFORE CHRISTMAS. THE WESTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS CAN EXPECT A WET MORNING WITH ISOLATED SEVERE STORMS TO CREATE A SHOPPING HAZARD. A MORE OMINOUS THREAT EXISTS EAST OF THE I-35 CORRIDOR WHERE DAYTIME HEATING WILL ENHANCE THE SEVERE WEATHER THREAT INTO A THEAT FOR SUPERCELLS AND TORNADOES. IF IT WERE NOT FOR THE MORNING STREAMER CELL SPEEDS OF AROUND 30 TO 35 MPH, WOULD BE CONCERNED OF A FLASH FLOOD THREAT. SOILS REMAIN NEARLY SATURATED FROM PREVIOUS RAINS, BUT WITH PRECIPITABLE WATER VALUES HOLDING BELOW 1.5 FOR THE MOST PART, EXPECT ONLY THREAT OF SUSTAINED HEAVY RAINS TO BE IN THE PATHS OF ANY SUPERCELLS THAT DEVELOP OVER THE SOUTHEASTERN COUNTIES LATER TODAY. WILL MENTION LOCALLY HEAVY RAINFALL FOR THE EASTERN TWO-THIRDS WITH SEVERE WORDING MENTIONED AREA-WIDE. WITH 06Z SATELLITE TRENDS SHOWING A SLIGHT EASTWARD POSITION OF THE UPPER LOW CENTER COMPARED TO FORECAST AND A PAIRED JET PATTERN INDICATING DEEPENING OVER CENTRAL TEXAS FOR THE NEXT 12 HOURS, THE QPF TRENDS WILL PROBABLY BE A BIT AHEAD OF THE ALREADY FASTER GFS. RAINFALL INTENSITIES ARE STEADILY INCREASING IN RESPONSE TO THE LOW LEVEL JET OVER THE CENTRAL COUNTIES. WITH A NEAR SOLID AREA OF RAIN EXPECTED OVER THE CENTRAL PORTIONS HALF OF THE FORECAST AREA BY AROUND DAYBREAK, WILL CALL FOR HIGH POPS OF 80 TO 100 PERCENT OVER THE EASTERN TWO-THIRDS. HELICITIES COULD APPROACH 500 M2S2 OVER THE SOUTHEASTERN COUNTIES TOWARD NOON ACCORDING TO THE RUC; WITH 1500 J/KG OR GREATER CAPES, THE THREAT FOR SEVERE WEATHER AND TORNADOES NEEDS TO BE WORDED STRONGLY HERE. FOR WESTERN SECTIONS, WILL KEEP POPS IN THE 50-60 PERCENT RANGE WITH SEVERE WORDING THROUGH THE AFTERNOON. DAYTIME HEATING COULD TRIGGER A FEW HAILSTORMS DESPITE A GOOD DRY PUNCH ENTERING WEST TX. WITH THE FASTER SPEED, WILL PLAN ON LESS MOISTURE BEING AVAILABLE WHEN THE BASE OF THE TROUGH LIFTS ACROSS THE FORECAST AREA TUESDAY. WILL TRIM POPS TO A SLIGHT CHANCE NORTHEAST. OTHERWISE A WARM AND DRY ZONAL PATTERN WILL RESUME AGAIN FOR THE NEXT SEVERAL DAYS UNTIL THE GFS AND NOGAPS DEPICT ANOTHER VIGOROUS STORM SYSTEM THREATENING THE SOUTHERN PLAINS EARLY NEXT WEEK. A WEAK SHORTWAVE MOVES THROUGH MAINLY NORTH TEXAS THURSDAY, BUT THE AIR SHOULD BE TOO DRY TO SUPPORT MEASURABLE RAINS OVER SOUTH CENTRAL TEXAS. PRELIMINARY NUMBERS... AUS 066/041/052/030/057 +5200 DRT 071/043/056/034/061 52-00 SAT 071/042/057/035/059 +4-00 .EWX...NONE. 18/3/PM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 545 AM CST MON 23 DEC 2002 PRECIPITATION HAS BROKEN OUT ACROSS THE PANHANDLES THIS MORNING AS BROAD AREA OF MID-LEVEL LIFT AND UPPER LEVEL DIFFLUENCE SPREADS OVER THE SOUTHERN PLAINS IN ADVANCE OF STRONG MID/UPPER LEVEL LOW TO THE WEST. SHORT RANGE MODELS STILL APPEAR TO BE HAVING A TOUGH TIME DEALING WITH MID/UPPER LEVEL LOW...EITHER DEPICTING A DEEP TROUGH OR A VERY WEAKLY CLOSED MID LEVEL LOW AT BEST. HOWEVER...PER ANALYSIS OF UPPER AIR DATA AND WV IMAGERY IT SEEMS THAT MID LEVEL CIRCULATION MAY BE A BIT MORE CLOSED OFF THAN MODELS ARE INDICATING. ALSO... MODELS APPEAR TO HAVE UNDERESTIMATED STRENGTH OF JET STREAK DIVING SOUTH OFF THE COAST OF SOUTHERN CALIFORNIA...WHICH WOULD SUGGEST THAT THE MID-LEVEL CIRCULATION WOULD REMAIN CLOSED A LITTLE LONGER. PRIMARY IMPACT TO THE PANHANDLES DUE TO THE ABOVE DISCREPANCIES WOULD BE REFLECTED IN INTENSITY AND DURATION OF PRECIPITATION. CONSIDERING THE AFOREMENTIONED OBSERVATIONS FORECAST PACKAGE WAS BASED TOWARDS THE TREND OF A SLIGHTLY SLOWER SOLUTION. SEVERAL HOURS OF RUC40/LAPS ANALYSIS CONTINUE TO SHOW VERY STRONG ISENTROPIC UPGLIDE AND STRONG 700-500MB DIV-Q VALUES ACROSS THE AREA WHICH IS STRONGER THAN WHAT LAST EVENINGS SHORT RANGE MODELS WERE INDICATING. ANOTHER SIGN OF A SYSTEM MORE INTENSE THAN EXPRESSED BY THE MODELS. THEREFORE...SHIFT TEAM DECIDED TO INCLUDE ALL OF THE TX/OK PANHANDLES IN A HEAVY SNOW WARNING FOR BOTH TODAY AND TONIGHT WITH UP TO 10 INCHES IN THE NE TX PANHANDLE BY TUESDAY MORNING...AND CONTINUE WITH A CHANCE OF SNOW ON TUESDAY. AFTER TUESDAY ONLY SOME MINOR CHANGES WERE MADE TO FORECAST. SHOULD BE PARTLY TO MOSTLY CLOUDY AND DRY. SNOW COVER WILL LIKELY TEMPER WARMING TREND TO A VERY GRADUAL RATE THROUGH THE WEEKEND. FCSTID = 04 AMARILLO 30 21 31 16 / 100 100 30 10 BEAVER 30 19 32 13 / 100 90 30 10 BOISE CITY 27 18 31 11 / 100 80 30 10 BORGER 32 20 31 15 / 100 100 30 10 BOYS RANCH 31 19 31 15 / 100 100 30 10 CANYON 30 21 32 16 / 100 100 30 10 CLARENDON 35 23 33 17 / 100 100 30 10 DALHART 29 18 31 14 / 100 90 30 10 GUYMON 28 18 32 13 / 100 90 30 10 HEREFORD 30 21 32 16 / 100 100 30 10 LIPSCOMB 33 20 32 15 / 100 100 40 10 SHAMROCK 36 23 33 17 / 100 100 40 10 WELLINGTON 37 24 34 18 / 100 100 40 10 .AMA... TX...HEAVY SNOW WARNING FOR TODAY AND TONIGHT TXZ001>020. OK...HEAVY SNOW WARNING FOR TODAY AND TONIGHT OKZ001>003. JH tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 845 AM CST MON DEC 23 2002 UPDATED FCST FOR N-C WI TO MENTION SNOW ACCUMULATIONS. BAND OF SNOW WITH VORT MOVG THROUGH THE AREA. RUC PROGS VORT TO SHEAR EWD...SO AMNT OF SWD MVT OF BAND IN QUESTION. MINOR ADDITIONAL CHANGES ALSO MADE TO THE REST OF THE FCST. .GRB...NONE. $$ JS/RE WWW.CRH.NOAA.GOV/GRB wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 229 PM MST MON DEC 23 2002 FORECAST CONCERNS ARE EXTENT AND AMOUNT OF SNOWFALL TONIGHT... TEMPERATURES THROUGHOUT...AND STRENGTH OF NORTHERN STREAM SYSTEM ON WEDNESDAY NIGHT AND THURSDAY. SATELLITE SHOWING POWERFUL JET STREAMING ACROSS THE PACIFIC. FLOW IS AMPLIFIED FROM EASTERN PACIFIC INTO NORTH AMERICA. SYSTEM OVER THE DESERT SOUTHWEST IS STARTING TO KICK OUT. QUESTION IN THE SHORT TERM IS HOW FAR NORTH THIS SYSTEM WILL MOVE AND ITS AFFECT ON THE SNOWFALL FORECAST. AT JET LEVEL...160-180 KNOT JET OVER THE PACIFIC. THE GFS LOOKED TO DO THE BEST ON THIS. 100-120 KNOT JET ON WEST SIDE OF DESERT SOUTHWEST SYSTEM. THE MODELS ARE TOO LOW WITH THIS JET SEGMENT. THE GFS/ETA DID THE BEST WITH THE ETA SLIGHTLY BETTER. AT MID LEVELS...ETA WAS THE WORST OF THE BUNCH. IT WAS TOO FAR NORTH AND EAST WITH CENTER OF DESERT SOUTHWEST SYSTEM. BASED ON HEIGHT ANALYSIS AND SATELLITE...THE GFS WITH THE NGM SECOND MATCHED UP BETTER WITH THIS SYSTEM...AND WAS FURTHER SOUTH AND WEST WITH FEATURES THROUGH SIX HOURS AT 500 MB. GFS AND RUC WERE ALSO DOING WITH 700 MB CIRCULATION NEAR EASTERN NEW MEXICO AND WEST TEXAS BORDER. AT LOW LEVELS...MODELS TENDED TO BE A LITTLE COLD. OVERALL... GFS DID A LITTLE BETTER. WILL BE BLENDING THE RUC/GFS FOR TONIGHT AND THEN LEAN TOWARD THE GFS FOR THE REST OF THE SHORT TERM. HOWEVER...WILL MODIFY IT BASED ON KNOWN BIASES...ESPECIALLY ON ITS COOL BIAS. FOR TONIGHT/TUESDAY...IF JET PROGS/HEIGHT FALL ANALYSIS IS CORRECT... SOUTHWEST SYSTEM SHOULD START KICKING OUT LATE THIS AFTERNOON AND EARLY THIS EVENING WITH BULK OF ENERGY GOING THROUGH WEST TEXAS. SATELLITE SHOWING DRY SLOT PUNCHING FROM THE SOUTH AS SOUTHERN PLAINS CONVECTIONS HAS MOVED TO THE EAST. RUC/GFS AND EVEN THE ETA AGREE ON KEEPING THE DEEPEST MOISTURE AND BEST LIFT OVER THE SOUTHERN SIX COUNTIES. MOISTURE/LIFT DECREASES EARLIEST IN GOVE AND LOGAN WITH LIFT SHIFTING TO THE SOUTHWEST SECTION FOR THE REST OF THE EVENING. HAVE LITTLE TO NO LOW LEVEL UPSLOPE HELP. TO MAKE THINGS SIMPLE WILL PUT SOUTHERN FIVE KANSAS COUNTIES TOGETHER AND CHEYENNE BY ITSELF. BECAUSE DRY SLOT AND SOUTHERN PLAINS CONVECTION ROBBING MOISTURE...THINK FOR NOW 1 TO 3 INCHES LOOKS GOOD WITH GREELEY AND WICHITA GETTING THE BEST OF IT. WILL THEREFORE BE ISSUING NO HIGHLIGHTS. MID AND UPPER LEVEL RIDGING... DOWNWARD MOTION...AND DRIER WILL PREVAIL FURTHER NORTH. WILL HAVE NOTHING IN THE NORTH WITH LOWER CHANCE POPS IN THE MIDDLE. RIDGING WILL PREVAIL DURING THE DAY. SKIES SHOULD CLEAR DURING THE DAY. PLAN GOING NEAR TO MAV MOS. FOR TUESDAY NIGHT/WEDNESDAY...RIDGING AND WESTERLY FLOW ALOFT WILL KEEP IT DRY WITH ONLY SOME CLOUDS EXPECTED. GOOD RADIATIONAL CONDITIONS EXPECTED AND MAV MOS LOOKS REASONABLE. WEAK DOWNSLOPE WINDS EXPECTED DURING THE DAY. MAV MOS LOOKS A LITTLE COOL CONSIDERING THE AMOUNT OF SUN EXPECTED AND SOME DOWNSLOPE. HOWEVER... ETA IS PROBABLY TOO WARM. WILL TEND TO GO NEAR TO SLIGHTLY ABOVE MAV GUIDANCE. FOR WEDNESDAY NIGHT/THURSDAY...GFS IS BRINGING DOWN SYSTEM THROUGH NORTHERN PLAINS DURING THIS TIME. GFS HAS HAD A TENDENCY OF OVERBLOWING THIS SYSTEMS LATELY. HOWEVER...CAN SEE THE POTENTIAL FOR DEEPING AND STRENGTHENING OF SYSTEM DUE TO UPPER LEVEL RIDGING AND JET STRUCTURE EXPECTED. THE MAIN CONCERN WITH THIS SYSTEM WILL BE ANOTHER COLD SHOT WITH BREEZY TO WINDY CONDITIONS...AND WILL HAVE TO BE MONITORED CLOSESLY. AVN LOOKS A LITTLE COLD. WILL HAVE SOME SUN AND SOME DOWNSLOPING WINDS TO OFFSET COLD AIR ADVECTION. WILL TEND TO GO NEAR TO SLIGHTLY ABOVE NUMERICAL GUIDANCE. IN THE 4 TO 7 DAY PERIOD...ECMWF AND GFS LOOK TO BE DOING THE BEST AS OF THIS MORNING. IF ANYTHING...THEY ARE PROBABLY TOO FAST IN KICKING OUT CURRENT SOUTHWEST SYSTEM. FRIDAY AND SATURDAY LOOK DRY AND WARMER THAN GUIDANCE AHEAD OF NEXT SYSTEM/JET MOVING IN SATURDAY NIGHT AND SUNDAY. ECMWF IS MORE AMPLIFIED THAN PREVIOUS RUN DURING THIS TIME PERIOD...BUT DOES NOT REFLECT IT DOWNSTREAM. GFS/MRF SHOW A STRONGER SYSTEM MOVING THROUGH SATURDAY NIGHT/SUNDAY. THINK FLOW WILL BE MORE AMPLIFIED THAN CURRENTLY PROGGED WITH SYSTEM STILL COMING OUT OF THE NORTHWEST. CURRENTLY SUNDAY IS DRY WITH LOW POPS ON THE GUIDANCE. AT THIS TIME...WILL KEEP IT DRY BUT WILL HIT THE CLOUDS HARDER AND LOWER THE TEMPERATURES SOME. EVEN WITH STRONGER SYSTEM MOVING THROUGH SUNDAY...THE GUIDANCE FOR MONDAY LOOKS TOO COLD...AND WILL GO NEAR CLIMOTOLOGY AT THIS TIME. .GLD...NONE. BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 255 PM EST MON DEC 23 2002 TNGT/TUE: MODELS STILL HAVE NOT COME UPON A COMMON SOLUTION REGARDING THE TIMING OF THE INCOMING PRECIP... THUS CONFIDENCE IS REDUCED. DO BELIEVE WE'LL SEE A LENGTHY PERIOD OF RAIN... AND BASED ON THE RUN-TO-RUN TRENDS OF THE MODELS... LATEST PRECIP TREND... AND THE LATEST RUC... WILL DELAY PRECIP ONSET UNTIL A FEW HOURS PRIOR TO AND SEVERAL HOURS AFTER 12Z TOMORROW. WILL HAVE THICKENING CLOUDS OVERNIGHT... BASICALLY AMOUNTING TO MOSTLY CLOUDY OR CLOUDY. CONTINUED RAINY AND COOL WORDING FOR TUESDAY. WITH CONSIDERABLY DIFFERENT H8 WIND FIELDS AND UPPER DIVERGENCE PATTERNS AMONG THE MODELS... AM VERY UNCERTAIN ABOUT QPF BUT WILL GENERALLY GO LESS THAN AN INCH FOR NOW & LET LATER SHIFTS ADJUST. LITTLE IF ANY CHANGE TO CURRENT LOWS TONIGHT... MAINLY 35 TO 40. ONLY A ONE OR TWO CATEGORY DIURNAL RISE FOR HIGHS TUE. TUE NGT/WED: EXPECT THE MOST WIDESPREAD RAIN TO TAPER OFF LATE IN THE AFTERNOON OR EARLY EVENING AS H8 WINDS DIMINISH & THE MILLER B SURFACE LOWS HEAD NE. BAGGY LOW LEVEL FLOW WILL BRING A RISK OF THE RAIN TAPERING OFF TO AREAS OF DRIZZLE THROUGH WED MORNING. EXPECT DOWNSLOPING TO KICK IN AND CLEAR OUT ANY PRECIP BY THE AFTERNOON. WILL MAKE FEW SIGNIFICANT CHANGES TO THE CURRENT LOWS/HIGHS AS THEY ARE IN LINE WITH CURRENT GUIDANCE NUMBERS. -GIH WEDNESDAY NIGHT THROUGH MONDAY: LITTLE CHANGE TO CURRENT FORECAST. NO CONFIDENCE IN ADDING RAIN 190 HOURS OUT AND WILL KEEP FORECAST DRY. WILL INDICATE SOME CLOUDS FRIDAY AND FRIDAY NIGHT AND ON MONDAY...OTHERWISE MOSTLY CLEAR WITH GENERALLY BELOW NORMAL TEMPERATURES THURSDAY FRIDAY AND NEAR TO A BIT ABOVE BEYOND. -RLH .RAH...NONE. HARTFIELD/RLH nc SOUTH CENTRAL TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 1103 AM CST MON DEC 23 2002 HAVE RAISED MOST TEMPS TO THE 70S RANGE AND ADJUSTED WINDS. NEXT AREA TO WATCH FOR CONVECTION APPEARS TO BE OVER THE HILL COUNTRY AROUND JUNCTION OR LEAKEY. .EWX...TOR WATCH #798 TIL 3 PM LEE LAVACA AND FAYETTE 06/08 PREVIOUS DISCUSSION... ONE OF THE MORE SIGNIFICANT TORNADO/SEVERE WEATHER THREATS OF THE YEAR FOR SOUTH CENTRAL TEXAS COMES TWO DAYS BEFORE CHRISTMAS. THE WESTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS CAN EXPECT A WET MORNING WITH ISOLATED SEVERE STORMS TO CREATE A SHOPPING HAZARD. A MORE OMINOUS THREAT EXISTS EAST OF THE I-35 CORRIDOR WHERE DAYTIME HEATING WILL ENHANCE THE SEVERE WEATHER THREAT INTO A THREAT FOR SUPERCELLS AND TORNADOES. IF IT WERE NOT FOR THE MORNING STREAMER CELL SPEEDS OF AROUND 30 TO 35 MPH, WOULD BE CONCERNED OF A FLASH FLOOD THREAT. SOILS REMAIN NEARLY SATURATED FROM PREVIOUS RAINS, BUT WITH PRECIPITABLE WATER VALUES HOLDING BELOW 1.5 FOR THE MOST PART, EXPECT ONLY THREAT OF SUSTAINED HEAVY RAINS TO BE IN THE PATHS OF ANY SUPERCELLS THAT DEVELOP OVER THE SOUTHEASTERN COUNTIES LATER TODAY. WILL MENTION LOCALLY HEAVY RAINFALL FOR THE EASTERN TWO-THIRDS WITH SEVERE WORDING MENTIONED AREA-WIDE. WITH 06Z SATELLITE TRENDS SHOWING A SLIGHT EASTWARD POSITION OF THE UPPER LOW CENTER COMPARED TO FORECAST AND A PAIRED JET PATTERN INDICATING DEEPENING OVER CENTRAL TEXAS FOR THE NEXT 12 HOURS, THE QPF TRENDS WILL PROBABLY BE A BIT AHEAD OF THE ALREADY FASTER GFS. RAINFALL INTENSITIES ARE STEADILY INCREASING IN RESPONSE TO THE LOW LEVEL JET OVER THE CENTRAL COUNTIES. WITH A NEAR SOLID AREA OF RAIN EXPECTED OVER THE CENTRAL PORTIONS HALF OF THE FORECAST AREA BY AROUND DAYBREAK, WILL CALL FOR HIGH POPS OF 80 TO 100 PERCENT OVER THE EASTERN TWO-THIRDS. HELICITIES COULD APPROACH 500 M2S2 OVER THE SOUTHEASTERN COUNTIES TOWARD NOON ACCORDING TO THE RUC; WITH 1500 J/KG OR GREATER CAPES, THE THREAT FOR SEVERE WEATHER AND TORNADOES NEEDS TO BE WORDED STRONGLY HERE. FOR WESTERN SECTIONS, WILL KEEP POPS IN THE 50-60 PERCENT RANGE WITH SEVERE WORDING THROUGH THE AFTERNOON. DAYTIME HEATING COULD TRIGGER A FEW HAILSTORMS DESPITE A GOOD DRY PUNCH ENTERING WEST TX. WITH THE FASTER SPEED, WILL PLAN ON LESS MOISTURE BEING AVAILABLE WHEN THE BASE OF THE TROUGH LIFTS ACROSS THE FORECAST AREA TUESDAY. WILL TRIM POPS TO A SLIGHT CHANCE NORTHEAST. OTHERWISE A WARM AND DRY ZONAL PATTERN WILL RESUME AGAIN FOR THE NEXT SEVERAL DAYS UNTIL THE GFS AND NOGAPS DEPICT ANOTHER VIGOROUS STORM SYSTEM THREATENING THE SOUTHERN PLAINS EARLY NEXT WEEK. A WEAK SHORTWAVE MOVES THROUGH MAINLY NORTH TEXAS THURSDAY, BUT THE AIR SHOULD BE TOO DRY TO SUPPORT MEASURABLE RAINS OVER SOUTH CENTRAL TEXAS. PRELIMINARY NUMBERS... AUS 066/041/052/030/057 +5200 DRT 071/043/056/034/061 52-00 SAT 071/042/057/035/059 +4-00 .EWX...NONE. 18/3/PM tx COASTAL BEND FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1025 AM CST MON DEC 23 2002 UPDATED THE ZONES TO REMOVE THE MENTION OF STRONG THUNDERSTORMS FOR THIS MORNING AND REMOVE MENTION OF TORNADO WATCH. TEMPERATURES AND SKY CONDITIONS ON TRACK. LOWERED POPS IN SOME AREAS...BUT KEEP THE MENTION OF SHOWERS AND THUNDERSTORMS FOR ALL BUT THE FAR WESTERN COUNTIES. LOW LEVEL MOISTURE SHOULD RAPIDLY DECREASE TODAY FROM THE WEST AS WIND VEERS AROUND TO THE SOUTHWEST IN RESPONSE TO DEVELOPING LOW JUST TO OUR NORTHWEST. SCATTERED SHOWERS AND THUNDERSTORMS STILL POSSIBLE LATER TODAY AND TONIGHT ALONG AND AHEAD OF THE FRONT. THIS WILL MAINLY BE IN THE EAST COUNTIES WHERE MOISTURE AND INSTABILITY WILL BE SUFFICIENT TO SUPPORT SHOWERS AND THUNDERSTORMS. MARINE...FOR THE UPDATE WILL BE TO KEEP WINDS SOUTH TODAY...AND NOT VEER THEM TO THE SW. BELIEVE THE AVN IS TOO COURSE WITH ITS RESOLUTION OF THE SURFACE LOW IN CENTRAL TX...AND PREFER THE MESO-ETA/RUC SOLUTION OF KEEPING SOUTH WINDS TODAY. PRESSURE GRADIENT SHOULD INCREASE AS CYCLOGENESIS TAKES PLACE IN THE HILL COUNTRY LATE MORNING/AFTERNOON AND WILL KEEP SPEEDS AS FORECAST. WILL ALSO LOWER PRECIP CHANCE OVER THE BAYS AS DYNAMICS ARE QUICKLY SHIFTING TO THE EAST. .CRP...SCA GMZ230-235-250-255-270-275. 78/92 tx SOUTHEAST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 944 AM CST MON DEC 23 2002 CURRENT HOT SPOT FOR TORNADOES WAS ENTERING INTO THE WESTERN FRINGES OF SE TX AT THIS HOUR. FORECAST PROBLEM OF THE DAY CONCERNS THE TORNADO AND SEVERE THREAT...THOUGH A SECONDARY CONCERN IS THE FLOOD POTENTIAL. THE 12Z CRP SOUNDING HAD HELICITY VALUES OF 419...A CAPE OF 2554...AND A PW OF 1.42. THE 1.42 INCH PW IS CLOSE TO 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. THE RUC HAS VERIFIED THE BEST SO FAR THIS MORNING OVER THE GFS AND ETA. THE RUC PLACES HELICITY VALUES IN EXCESS OF 400 FOR ALL OF SE TX THROUGH 21Z THIS AFTERNOON. THE SURFACE WARM FRONT AT 15Z WAS LOCATED FROM JUST NORTH OF AUS EASTWARD ACROSS THE NORTHERN THIRD OF SE TX WITH A SURFACE LOW SOUTH OF JCT. ALSO...THE UPPER JET WAS KEEPING THE AREA UNDER THE BEST LIFT. THIS SCENARIO WILL KEEP SE TX IN THE BEST AREA FOR SEVERE WEATHER. AM EXPECTING THE SHOWERS STARTING TO POP OVER THE SOUTHEASTERN THIRD OF THE FORECAST AREA TO BUILD AS THEY MOVE NORTHWARD. ONE CONCERN WE HAVE IS THAT THE CONVECTION CURRENTLY FIRING WILL BUILD INTO AN MCS WHICH WILL HIGHLIGHT THE HEAVY RAINFALL THREAT. A NEW WATCH WILL BE ISSUED SHORTLY AND WILL UPDATE THE PUBLIC FORECAST BY THE TOP OF THE HOUR. WILL TWEAK TEMPERATURES AND WINDS AT THAT TIME AS WELL. .HGX...FLASH FLOOD WATCH ALL OF SOUTHEAST TEXAS. SCA GALVESTON AND MATAGORDA BAYS. SCA 00 TO 60 NM HIGH ISLAND TO THE MATAGORDA SHIP CHANNEL. PREV DISC... THE BIG STORY IS THE WEATHER TODAY AND TONIGHT. TORNADO OUTBREAK TAKING SHAPE FOLLOWED BY A SQUALL LINE TO CLEAR THINGS OUT LATE THIS AFTERNOON-MIDNIGHT. THUNDERSTORMS DEVELOPING OVER THE HILL COUNTRY ALONG THE WARM FRONT FROM SOUTH OF SAN ANTONIO TO SUGARLAND TO NEAR GALVESTON. SPEED MAX SOUTHWEST OF BIG BEND WILL SHIFT EAST AS THE UPPER TROUGH SLIDES EAST. THIS JET WILL BE SPLITTING AS IT GETS INTO THE AREA AROUND NOON. AT 06Z LLJ AXIS FROM THE EXTREME WESTERN GULF AIMED AT SAN ANTONIO WHERE THE DEVELOPING CONVECTION IS OCCURRING. GPS DERIVED PW ALONG THE COAST FROM CRP TO GLS INDICATES 1.15-1.3" PW ALREADY SURGING INLAND. THE LLJ AXIS MOVES EAST INTO THE FA AROUND 18Z WITH PW RISING TO AROUND 1.4 TO 1.5" WITH RICHER MOISTURE AIMED AT LA. LOW LEVEL SHEAR WITH HELICITIES THIS MORNING 200-240M2 INCREASING THIS AFTERNOON TO PERHAPS AS HIGH AS 300M2...WITH LCL 1200FT OR LESS. LI PLUNGES FROM AROUND -2 TO -8 WITH NO CAP. UNFORTUNATELY THE AREA LOOKS LIKE IT WILL GET DRY SLOTTED AT AROUND 21Z! THIS SHOULD OPEN THE GATES TO RAPIDLY INCREASE THE SEVERITY OF THE TORNADO THREAT OVER THE CENTRAL AND EASTERN ZONES. CURRENT PACKAGE ALREADY CARRIES 100 POPS FOR INLAND AREAS AND 80 POPS COAST WITH SEVERE AND A FOCUS ON TORNADOES. ETA AND GFS BOTH SUPPORT A SCENARIO WHERE THE CORRIDOR OF SUPERCELLS SHIFTS ACROSS SOUTHEAST TEXAS LEAVING BEHIND ENOUGH MOISTURE FOR A SQUALL LINE TO DEVELOP EMBEDDED IN A VERY STRONG WIND FIELD LATE THIS AFTERNOON AND RACING ACROSS BETWEEN 6 PM AND MIDNIGHT. VERY DRY/COLD AIR ALOFT SHOULD MAKE THE DOWNDRAFT IN THE SYSTEM VERY EFFECTIVE SO WILL ADJUST THE FORECAST CONCERNING THIS ISSUE. LOCALLY HEAVY RAINFALL STILL AN ISSUE. EXTREMELY MOIST ATMOSPHERE FOR THIS TIME OF YEAR AND 1000-500MB THICKNESS VALUES AROUND 5660M AND DECREASING AS LLJ TRAVERSES THE AREA WITH THE ABOVE MENTIONED UPPER JET STRUCTURE AND THE EXPECTED WIDESPREAD DEVELOPMENT SUPPORTS THE CONTINUED MENTION OF LOCALLY HEAVY RAINFALL. WILL ISSUE A FLASH FLOOD WATCH BUT WILL LIKELY NEED DAY SHIFT TO REFINE THE THREAT AREA BASED ON LOCATION OF AND THE DEEP CONVECTIVE DEVELOPMENT ON AND NORTH OF THE WARM FRONT. THE SHOW SHOULD BE OVER BY 6-9Z TUE AS IT ROARS OUT OVER THE GULF AND INTO LA. WRAP AROUND TRAPPED MOISTURE SHOULD DRAG IN CLOUDS THROUGH MOST OF TUESDAY WITH CLEARING LATE AFTERNOON. AREA REMAINS DRY IN THE WAKE AS WESTERLY FLOW VEERS TO NW AND PRECIP CHANCE DROP. WEATHER SHOULD GOOD FOR SANTA TO DELIVER TOYS TO SOUTHEAST TEXAS ON CHRISTMAS EVE. NEXT SHOT AT RAIN MAY NOT COME AROUND TIL SUNDAY BUT MRF LOOKS LIKE IT IS TOO FAST AND TOO DEEP WITH THIS SYSTEM SO WILL CONTINUE THE PARTLY CLOUDY FORECAST GOING FOR SUNDAY MORE IN LINE WITH THE ECMWF. PREV PRELIMS... CLL TE 065/042 052/030 050 +71 IAH TE 071/045 054/033 050 +92 GLS TE 073/052 057/041 051 892 45/36 tx