AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 930 PM EST MON DEC 10 2001 RADAR MOSAIC SHOWS BACK EDGE OF PRECIP FIELD IS APPROACHING THE FORECAST AREA AT THIS TIME. RUC SUGGESTS PRECIP WILL END ACROSS ENTIRE FORECAST AREA BY 06Z. WILL UPDATE ZONES TO REFRESH WORDING BUT WILL WAIT UNTIL LATE IN ORDER TO DETERMINE PRECIP TREND. WILL LIKELY AT LEAST LOWER POPS TO CHANCE IN THE EASTERN-MOST ZONE AND REMOVE MENTION OF POPS IN THE WESTERN ZONES. OTHER FORECAST PARAMETERS APPEAR ON TRACK AND WILL MAKE NO OTHER CHANGES. .JKL...NONE. LCM ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1115 AM EST MON DEC 10 2001 WV LOOP DEPICTING SHEARED OUT NRN STREAM SHRTWV FM HUDSON BAY INTO NERN MN ATTM. WEAK TROUGH CO-LOCATED JUST AHEAD OF SHRTWV HAS PASSED CMX AND IWD THIS MORNING WITH A BAND OF STRATUS AS THE CALLING CARD. 06Z ETA 280K (H9) ISENTROPIC SFC SHOWED THIS WELL ALTHOUGH ABOUT 6HR TOO SLOW WITH MOVEMENT TO EAST. FIELD OF SUB 3KFT STRATUS ALSO FILLING IN BEHIND TROUGH ASSOCIATED WITH H95-H85 THERMAL TROUGH. PATCHY LGT SNOW OBSERVED NEAR ANGLE INLET IN NRN MN WITH A FEW OTHER STATIONS INTO SW OT AND MB ALSO YIELDING FLURRIES. ALBEIT WEAK IT APPEARS THAT THE LATEST RUC H9-H8 2D FRONTOGENESIS IS DEPICTING THIS FLURRY ACTIVITY BEST. OUT AHEAD OF TROUGH MUCH OF FA UNDER SCT-BKN AC WHICH IS PARTIALLY BLOCKING MORNING SUNSHINE. PASSAGE OF TROUGH THIS AFTN WL ALLOW AT LEAST BKN STRATUS TO FILTER IN ACROSS NRN TIER OF FA THIS AFTN PER RUC/ETA H925...WITH CLOUDS BECOMING MORE SCT FARTHER SOUTH AND EAST AS CONVERGENCE WEAKENS ALONG BOUNDARY. FAIRLY WARM START THIS MORNING AND ANY SUNSHINE THIS AFTN SHOULD BOOST TEMPS TO AROUND THE 40F MARK...EVEN WARMER FARTHER SOUTH AWAY FM MORE BKN CLOUDS. CURRENT FCST HAS GOOD HANDLE ON THIS. BESIDES CLOUDS AND TEMPS CONCERN IS POSSIBILITY OF ANY FLURRIES ON THE KEWEENAW WITH WRLY FLW. 12Z INL RAOB DID SHOW DEEPER MOIST LAYER THAN EITHER THE ETA/RUC GAVE CREDIT FOR...EXTENDING TO NEAR H8. CWPL SOUNDING SHOWS ONLY NARROW LAYER OF MOISTURE NEAR H85 WITH VRY DRY LAYER BOTH ABOVE AND BELOW...SUGGESTING THE INL DEEPER MOISTURE IS ISOLATED IN NATURE. HOWEVER...THIS INCREASED MOISTURE WL ROTATE OVR WRN LAKE SUPERIOR AND CLIP KEWEENAW THIS AFTN. TEMPS IN MIXED LAYER ONLY FALL TO -6C/-3C AT 875MB/925MB BY 21Z...YIELDING DLT T/S OF 11C/8C BY LATE AFTN...OF WHICH THE 8C IS PROBABY A MORE FEASIBLE VALUE. ALTHOUGH THE WEAK FG MIGHT PROVIDE SOME FORCING DON/T THINK IT WL BE SUFFICIENT TO GENERATE ANY SIG PRECIP. SLIGHTLY COLDER AIR WORKS INTO KEWEENAW EARLY THIS EVENING...BUT BY THEN DRYING IS OCCURRING INTO MIXED LAYER (RUC H9 RH FALLING BLO 50 PCT BY 00Z). ALL IN ALL THERE COULD BE A FEW FLURRIES BUT NOTHING OF REAL SIGNIFICANCE LOOKS LIKELY. .MQT...NONE. JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 835 PM CST MON DEC 10 2001 THE FORECAST HAS BEEN UPDATED FOR A LITTLE COOLER TEMPERATURES OUT WEST AND DECREASED WINDS. CIRRUS COVERS MUCH OF THE STATE BUT TEMPERATURES HAVE ALREADY DROPPED INTO THE TEENS OVER THE WESTERN SNOW COVER. THE LATEST RUC KEEPS WINDS LIGHTER THROUGH 12Z AND DELAYS EJECTING HI PLAINS LOW. .MSP...NONE SCOTT mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 911 PM EST MON DEC 10 2001 EXACT TRACK OF SFC LOW NOW DEVELOPING OFF THE SC COAST WILL HAVE A HUGE IMPACT ON WHETHER WE GET A FEW LOW TOPPED SUPER CELLS OR NOT...OTHERWISE FCST ON TRACK WITH CATEGORICAL RAIN OVERNIGHT. TEMPERATURES NEAR THE COAST WILL FLUCTUATE OVERNIGHT. AFTER FALLING THIS EVENING...THEY WILL BRIEFLY RISE AS FLOW BECOMES SE...THEN FALL AGAIN TWRDS SUNRISE AS W/SW FLOW DEVELOPS WHEN SFC LOW TRACKS N OF THE REGION. TEMPERATURES WELL INLAND WILL LIKELY SLOWLY FALL OVERNIGHT DEPENDING ON HOW FAR INLAND THE LOW MOVES. SFC BASED INSTAB WAS LOCATED JUST OFF THE COAST ATTM WHERE A WELL DEFINED COASTAL TROUGH WAS LOCATED. THE TROUGH EXTENDED S TO A DEVELOPING LOW JUST SE OF CHS. INLAND 00Z RAOBS WERE DEVOID OF ANY CAPE AND EXHIBITED MOIST ADIABATIC PROFILES. IF AVN TRACK IS CORRECT SVR THREAT WILL REMAIN OFFSHORE...HOWEVER...THE ETA AND RUC40 MODELS MOVE THE LOW MUCH FURTHER WEST AND WOULD PRESENT MORE OF A THREAT FOR OUR AREA. MSAS PRES FALLS CENTERS WERE NEAR RDU AND JUST OFFSHORE SUGGESTING THAT THE LOW WOULD TEND TO HUG THE NC COAST. PRESENT THINKING IS THAT AN ISOLD SPIN UP WILL BE POSSIBLE...BUT CONFINED MAINLY TO THE IMMED COAST AFT 11 PM. CURRENT FCST HAS SITUATION WELL IN HAND AND PLAN ON NO UPDATE THIS EVENING. MARINE: STRONG SFC CONVERGENCE S OF CAPE FEAR WAS NOTED AHEAD OF SFC LOW OFFSHORE OF SC. THE FOCUS WILL SHIFT TO THE NE TWD MHX WATERS AS THE NIGHT PROGRESSES BETTERING CHANCES FOR STRONG TSTMS IN MARINE ZONES AND ALG IMMEDIATE COAST. KMHX VAD SHOWING DECENT DIR AND WSPD SHEAR. CURRENT FCST LOOKS GOOD AND WILL STICK WITH INCREASING WIND AND MENTION OF TSTMS. .MHX...SCA COASTAL WATERS AND SOUNDS. ELARDO/COLBY nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1040 AM EST MON DEC 10 2001 ...WILL TWEAK THIS AFTERNOONS FORECAST TO REMOVE MORNING WORDING AND ADJUST TEMPERATURES... SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED JUST TO OUR EAST WITH A COLD AIR DAMMING SIGNATURE EVIDENT DOWN THE EAST SLOPES OF THE APPALACHIANS. VISIBLE SATELLITE LOOP SHOWS HIGH CLOUDS INVADING FROM THE SOUTH. SOUTHERN STREAM SHORTWAVE PROGGED TO BECOME NEGATIVELY TILTED AS IT ADVANCES TOWARDS KENTUCKY THIS AFTERNOON. THIS WILL ALLOW OUR SKY COVER TO INCREASE THIS AFTERNOON. RUC CROSS SECTIONS SHOW MIXING IN THE WEST ONLY TO 950 MB. ABOUT ONE TO TWO DEGREES IN THIS LEVEL WILL ALLOW TEMPERATURES TO MAX OUT AROUND 40 IN THE WEST. WITH THE COLD AIR DAMMING...DONT EXPECT THE EAST TO MIX SUBSTANTIALLY AT ALL (SUPPORTED BY CROSS SECTIONS). WITH THE COMBINATION OF THE COLD AIR DAMMING AND INVADING CLOUDS FEEL CONFIDENT TO SLASH TEMPERATURES TO THE 30S IN THE EAST. WINDS WILL MIX TO SOUTHERLY IN THE WEST AND A VERY LIGHT SOUTHEAST WIND IN THE EAST. WILL HAVE TO TAKE A HARD LOOK AT THE SOUTHERN STREAM SYSTEM AS VERTICAL TEMPERATURE SIGNATURES AND PRECIPITATION SHIELD MAY SUPPORT FREEZING RAIN ACROSS THE SOUTHEAST TONIGHT. .CTP...NONE. ROGOWSKI/MARTIN pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 130 PM CST MON DEC 10 2001 SATELLITE SHOWING VORT CENTER PUNCHING INTO SOUTHWEST TENNESSEE EAST OF MEMPHIS AT EARLY AFTERNOON. KOHX DOPPLER CONTINUING TO SHOW SHOWERY PRECIP ACROSS THE AREA WORKING NORTHEAST. GREENWOOD DOPPLER SHOWING BACKSIDE OF SHOWERY AREA JUST ABOUT TO SAVANNAH/PICKWICK DAM AREA AT 1830Z. GOOD CLEARING BEHIND VORT CENTER ACROSS MISSISSIPPI. LATEST RUC MODEL SHOWING PRECIP STILL GOING ON OVER EASTERN AREAS OF MID STATE AND PLATEAU AROUND SUNDOWN BUT OUT OF MY CWA BY 03Z. WILL HAVE TO WATCH RADAR SCOPE AND TWEAK ZONES ACCORDINGLY FOR EARLY TONIGHT. ANOTHER RAIN CHANCE COMES OUR WAY FOR WEDNESDAY AS NEXT SYSTEM APPROACHES THE AREA FROM THE WEST. PRELIMINARY NUMBERS: NASHVILLE 40 57 47 60 55 2015 CROSSVILLE 40 53 43 55 54 60-4 .BNA...NONE. BOYD 01 tn DEEP SOUTH TEXAS FORECAST DISCUSSION...CORRECTED TO ADD ANOTHER PAR NATIONAL WEATHER SERVICE BROWNSVILLE TX 850 PM CST MON DEC 10 2001 STRONG JET EMBEDDED IN A DEEP TROF OVER MEXICO CONTINUES TO MOVE ACROSS MEXICO TONIGHT WITH SEVERAL AREAS OF PVA. THE STRONGEST OR MOST ORGANIZED ENHANCEMENT ON THE WATER VAPOR APPEARS TO BE MOVING ONTO THE WEST COAST OF MEXICO...JUST SOUTH OF THE BAJA PENINSULA. IT SEEMS THAT THIS ENHANCEMENT IS ASSOCIATED W/A SHORTWAVE THAT WAS IN THE SUB TROPICS THAT HAS BEEN PICKED UP BY THE DEEP TROF AND FAST FLOW...AND IS HEADING FOR DEEP S TX. EXPECT CONTINUED INCREASE UVV'S AND SATURATION FROM WARM AIR ADVECTION OVER THE COOL DOME..AND FROM UPPER LEVEL DIVERGENCE THRU TUES. THIS LIFT COULD PRODUCE SOME LIGHT RAIN TOWARD MORNING AND INTO THE DAY ON TUESDAY. HOWEVER...RAINFALL AMOUNTS SHOULD BE LIGHT W/LACK OF GOOD LOW LEVEL MOISTURE INFLOW. IN ADDITION...FEEL THAT W/SUCH A STRONG BAROCLINIC BOUNDARY LOCATED ALONG THE LOWER TX COAST W/TEMP RANGE FROM THE UPPER 50S ALONG THE COAST TO THE 70S OFFSHORE...COULD SEE A WEAK COASTAL LOW DEVELOP TUES W/DEEP TROF AND APPROACHING APPARENT SHORTWAVE. IF COASTAL LOW DEVELOPS....WINDS SHOULD REMAIN OUT OF THE NE THRU TOMORROW. IN FACT...THE RUC MODEL WAS THE ONLY MODEL TO PROG A WEAK COASTAL SFC LOW/TROF DEVELOPING SE OF BRO BY 12Z TUES. AS A RESULT...WILL ADD A SLIGHT CHANCE OF POPS TONIGHT AND RAISE POPS INTO THE CHC CATEGORY ON TUES FOR CONSISTENCY. WILL ALSO KEEP A E-NE WIND THRU TUES AS A WEAK COASTAL LOW TRIES TO DEVELOP. MARINE...NO CHANGES MADE TO MARINE ZONES AS SEAS REMAIN LOW. PUBLIC/AVIATION...GUERRERO MESO/UPPER AIR...ABBOTT INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx AREA FORECAST DISCUSSION...UDPATED NATIONAL WEATHER SERVICE WAKEFIELD, VA 953 AM EST MON DEC 10 2001 MAYBE...JUST MAYBE...THIS WL TURN OUT TO BE A SGFNT RA PRDCR FOR FA. THERE IS A WAY WHR WE DON'T GET WDSPRD 0.25" AND >. SYS FM LWR MS VLY LIFTING TO THE NE...UPR LVL PORTION PASSES ALG/JUST W OF MTNS...PSBLY LEADING TO BETTER CHCS FOR SGFNT RA TWD MTNS (UPSLPG)...WHL SCNDRY MSTR AREA CUD BE INVOF CST. FOR NOW...GOING FCST STANDS...WITH WDSPRD RA (PTNTLLY BEGINNING LT AFTN FAR WSW SXNS - WHICH FOLLOWS CURRENT SUGG FM 13Z RUC) TNGT INTO ERY TUE. CLDS ALREADY SPREADING QUIKLY INTO RGN...WL GO WITH MCLDY OVRALL. TEMP FCST TRICKY...BUT THINK CURRENT HI TEMPS WITHIN REACH. FCSTID = 25 .AKQ... MD...SCA ATLC CSTL WTRS FENWICK ISL TO CHINCOTEAGUE. NC...SCA ATLC CSTL WTRS NC/VA BRDR TO CURRITUCK BCH LGT. VA...SCA ATLC CSTL WTRS CHINCOTEAGUE TO NC/VA BRDR. va EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 PM PST MON DEC 10 2001 CURRENT PLAN IS TO LOWER ALL HIGHLIGHTS AS NORTHERN EXTENSION OF TROUGH HAS BEEN SLOW TO SLIDE SOUTHEAST. NORTHWEST FLOW NO LONGER TO SET UP WITH LOW LEVEL HORIZONTAL PRESSURE GRADIENTS QUITE WEAK. BEST VORTICITY ADVECTION WILL BE DIRECTED SOUTH-SOUTHEAST ALONG THE CASCADES WITH TROUGH PASSING EASTERN WA/NORTHERN ID DURING THE EARLY HALF OF TONIGHT. LATEST 18Z ETA AND RUC THIS WARRANTS CONTINUED MENTION OF AREAS OF SNOW MOST AREAS WITH HIGHER PROBABILITY ACROSS THE HIGHER TERRAIN. ACCUMULATIONS WILL BE LIGHT. NEXT SYSTEM IN THE SERIES STILL EXPECTED TO DIVE SOUTH-SOUTHEAST TUESDAY AFTERNOON WITH A FEW AREAS OF SNOW BREAKING OUT ACROSS THE EASTERN BASIN AND LESSER CHANCE EASTWARD. SOME LIGHT ACCUMULATIONS WILL OCCUR MAINLY FURTHER UP ALONG THE CASCADE EAST SLOPES. UPPER WIND MAX ASSOCIATED WITH THIS TROUGH HEADS SOUTHWARD BRINGING UNFAVORABLE LEFT ENTRANCE REGION THROUGH THE FORECAST AREA...MINIMIZING CHANCES OF PRECIPITATION ASIDE FROM LEFTOVER EVENING SHOWERS ACROSS THE SOUTHEAST. WARM ADVECTION BEGINS WEDNESDAY AS EAST PACIFIC RIDGE BEGINS TO FLATTEN...WITH MINOR RIPPLE OVERHEAD. WILL MENTION LOW POPS FOR WEDNESDAY WHILE IT WILL BE DIFFICULT TO TIME OR ASSESS THE PRECIPITATION AMOUNTS...IF ANY...AT THIS TIME. SURFACE LOW IN GULF OF ALASKA BRINGS A COLD FRONT TO THE CASCADES EARLY THURSDAY. EXPECT STEADY PRECIPITATION TO BREAK OUT LATE WEDNESDAY NIGHT WITH RISING SNOW LEVELS ENOUGH TO PROVIDE A PERIOD OF RAIN FOR THE VALLEYS BEFORE COLDER AIR ALOFT WORKS IN THE POST-FRONTAL WESTERLY FLOW. 850 MB WINDS WILL INCREASE IN THE 35-45 KNOT CATEGORY FOR BREEZY MENTION ON THURSDAY. JR .EXTENDED...AS PER AVN AND MRF KEEP BEST CHANCE OF WIDESPREAD PRECIPITATION OF THE EXTENDED PERIOD FRIDAY WHEN A SIGNIFICANT SHORTWAVE PASSAGE IS EXPECTED. ON SATURDAY FORECAST AREA IS ON THE NORTHEAST SIDE OF A DIRTY OFFSHORE RIDGE SO CONTINUE TO MENTION PRECIPITATION BUT WITH ONLY CHANCE WORDING...AND EVEN THEN A STILL SMALLER CHANCE FOR THE BASIN. SUNDAY AND MONDAY MOST OF THE AREA IS ON THE NORTHWEST SIDE OF THE DIRTY END OF A WESTERN US RIDGE WHICH PRETTY MUCH MERITS THE SAME FORECAST WORDING AS SATURDAY...THUS CLUMP SATURDAY SUNDAY AND MONDAYS FORECAST TOGETHER. ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 023/030/020/031/029/035 730367 COE 021/030/017/032/027/035 730367 PUW 023/031/019/033/030/036 74-367 LWS 029/035/025/036/033/041 442246 CQV 021/032/017/032/028/036 620367 SPT 019/031/017/031/028/033 720367 WWP 020/028/017/029/027/032 731367 EAT 027/034/025/035/032/037 240266 MWH 026/035/023/035/033/038 240266 .OTX...NONE. wa NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 245 AM MST TUE DEC 11 2001 SHORT TERM DISCUSSION: INITIAL EJECTING WAVE FROM THE DESERT SW IS ACROSS NW CO ATTM AND MOVING NE INTO SERN WY THIS MORNING. SURFACE LOW PRESSURE HAS ALSO SHIFTED INTO SRN WY WITH A HEALTHLY SW FLOW PATTERN REMAININ OVER CWA. SAT PICS STILL HINTING AT A LITTLE FOG ACROSS WELD/MORGAN COUNTIES BUT FOR THE MOST PART THERE IS ENOUGH SFC DOWNSLOPE WINDS AND WIDE ENOUGH T/TD SPREADS NOT TO BE TOO WORRIED ABOUT FOG THIS MORNING. 88-D IS SHOWING SOME CONTINUED SCT SHSN ACTIVITY IN THE MTNS AND ROAD REPORTS/WEB CAMS SHOWING SN- ATTM. X-SECTIONS IN THE MTNS SHOWING SOME LINGERING MSTR IN THE MTNS TDY BUT WITH CONTINUED SW FLOW AND NEGLIGIBLE FORCING BEHIND WAVE...WE'LL LOWER POPS TO THE SCT CATEGORY TDY. WITH THE PASSAGE OF THIS WAVE...GOOD DOWNWARD FORCING TODAY AND NOT MUCH MSTR OVER ERN CO. 700MB TEMPS CONTINUE TO COOL TDY DOWN TO AROUND -8C BY 00Z. HOWEVER ...WITH THE EROSION OF THE INVERSION AT 700MB SHOULD BE ABLE TO OBTAIN HIGHS AROUND YESTERDAY'S READINGS OR EVEN SLIGHTLY HIGHER. THINGS GET A BIT MORE INTERESTING TONIGHT AS MORE ENERGY EJECTS OUT OF THE BASE OF MEAN TROF ACROSS THE DESERT SW. SURFACE LOW PRESSURE REDEVELOPS OVER SERN CO LATER TDY AND TNT AND MODELS GENERATE A BAND OF PRECIP ACROSS E CNTRL CO...AND NICKS ZNS 46..47..AND 49. NEW 06Z MESOETA HAS BACKED OFF ON THIS A BIT BUT WILL STILL INDICATE HIGHER POPS DOWN ALONG SERN PERIPHERY OF CWA. THERE IS SOME WEAK UPSLOPE TNT SO WILL HOLD ONTO THE ONGOING ISOLD POPS OVER THE FRONT RANGE. ACROSS THE MTNS TNT...MSTR IS THERE...WEAK DYNAMICS...BUT 700MB FLOW IS QUITE WEAK ONLY 10KTS AND LAPSE RATES BETWEEN 6-7C/KM. CAN'T SEEM MUCH MORE THAN A FEW INCHES IN THE TNT PRD. ENTREKIN LONG TERM DISCUSSION: DESPITE THE FAIRLY DEEP TROF OVER THE ROCKIES THRU WED LUKS LIKE MOST OF THE SNOW WILL BE CONFINED TO THE MTNS...ALTHO TONITE'S ETA RUN RAISES A BIT OF CONCERN FOR THE PLAINS AS ONE OF THE S/WVS MOVING THRU THE OVERALL TROF TRIES TO PRODUCE SOME SNOW FOR TUE NIGHT INTO WED. PLENTY OF ENERGY RIDING DOWN W COAST WITH A STRONG JET STREAM AND TNGTS ETA ANALYSIS SHOWS S/W OVER SRN CA BIT FARTHER W THAN 12H ETA FCST...AND THIS POSITION LUKS GUD VS WTR VPR LOOP AND AVN AND RUC ANALYSES. ON THE OTHER HAND WAVE NOW ON BC COAST IS NOT QUITE AS STRONG IN TNGTS ETA BUT DIVES A BIT FURTHER W AND TAD FASTER...HOLDING TROF BACK A BIT VS 12Z ETA FOR WED THE AVN IS STRONGER WITH BOTH WAVES...ESPCLY THE ONE NOW ON THE BC COAST. THE FARTHER W POSITION OF THE TWO WAVES STILL DIVING INTO THE COAST RESULTS IN THE ETA AND NGM...AND TO A LESSER EXTENT THE AVN...BRINGING THE S/W FOR TUE NGT FARTHER N THAN IN THE PREVIOUS RUNS. THIS PRODUCES A BAND OF SIG PCPN MAINLY ACRS SRN CO TO WRN KS BUT GETS CLOSE TO OUR SRN ZONES ON THE PLAINS. THE ETA ACTUALLY SHOWS A BIT OF A CLOSED LOW AT 700 MB AS THIS SYSTEM COMES OUT TUE NGT SO WEAK BUT DEEPENING UPSLOPE PRODUCES SOME SNOW ALONG FRONT RANGE AND ESPCLY ZONE 41 AND EASTWARD THAT WUD CONT INTO WED. 06Z ETA RUN THEN BACKED OFF ON THIS 700 MB UPSLOPE. CANADIAN REGIONAL MODEL SHOWS A SIMILAR BAND OF PCPN...THO THE WEAKER AVN KEEPS IT FARTHER E IN KS FOR THE MOST PART AND HAS NW FLOW AT 700 MB. ATTM WE WILL HANDLE IT WITH SOME HIGHER POPS SRN PTN OF THE PLAINS UP TO 50 PCT. OTHRWS CRNT MTN ZONES LUK WITH A CONTINUATION OF SNOW SHWRS PROB REMAINING BELOW ADVY CRITERIA AS WINDS NOT THAT STRONG...THRU WED...THEN A BREAK UNTIL THE NEXT SYSTEM SHOWS UP TWDS FRIDAY. THE POSSIBLE SYSTEM FOR THIS WEEKEND HAS MANY UNCERTAINTIES...THO GENERAL AGREEMENT AMONG ALL THE MODELS (EC, UK, CAN, MRF, NOGAPS) THAT A MAJOR FULL LATITUDE TROF WILL DEVELOP OVER ROCKIES IN THE SAT/15 DEC TIMEFRAME. VARIATIONS OF COURSE ON HOW DEEP THE TROF WILL BE AND COULD BLOW BY AS AN OPEN WAVE WITH VERY LITTLE SNOW ON THE PLAINS...MUCH LIKE THE CURRENT TROF. THE SYSTEM IS JUST NOW EMERGING FROM A TROF OFF THE EAST COAST OF ASIA SO A LOT CAN HAPPEN OVER THE NEXT FEW DAYS. AMONG THE LATEST MODEL SIMULATIONS THE ECMWF HAS THE DEEPEST TROF WITH A SOMEWHAT N/S ORIENTED 500 MB LOW TRYING TO CLOSE OFF BY 12Z/SUN OVER NERN NM. ON THE OTHER HAND STRICTLY BUYING THE AVN/MRF WUD MEAN AN OPEN TROF MOVING ACRS CO ON SAT WITH GUD MTN SNOWS BGNG LATER FRI BUT NOTHING OF SIGNIFICANCE ON THE PLAINS. THE UKMET IS A LITTLE DEEPER AND SLOWER...SMWHT LIKE THE CANADIAN. THE LATEST NOGAPS IS ALSO DEEPER THAN ALL BUT THE EC MODEL. GIVEN THESE UNCERTAINTIES WILL KEEP THE MENTION OF SNOW IN THE CURRENT FCST FOR THIS WEEKEND...THO AT THIS POINT MODELS HAVE CERTAINLY SWERVED AWAY FROM THE STRONG CUTOFF SHOWN BY THE 10 DEC MRF RUN. SZOKE .DEN...NONE. co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 405 AM EST TUE DEC 11 2001 00Z RAOBS/LATEST WV LOOP AND RUC ANAL SHOW SPLIT FLOW WITH NR ZONAL/ PROGRESSIVE NRN BRANCH AFFECTING NRN CONUS/SRN CAN. SRN BRANCH MUCH MORE ACTIVE WITH DEEP TROF OVR THE SW AND ANOTHER SGNFT SHRTWV MOVG THRU THE SE AND CRASHING INTO PERSISTENT MEAN UPR RDG OVR THE SE. STRG NLY H3 WNDS ON BACK SIDE OF WRN TROF. VERY DRY AIR OVR SRN CAN AND CONUS EVEN DOWN TO GLF COAST AND SE CONUS WITH PW GENERALLY AOB 0.25 INCH. VIGOROUS SHRTWV OVR SE CO LIFTING NE OUT OF WRN TROF...BUT DRYNESS OF AIR LIMITING CLD COVER TO MAINLY JUST SOME HI CLDS THAT HAVE MOVD AS FAR NE AS MN. SFC 1022MB HI PRES OVR SRN ONTARIO BRINGING A RATHER TRANQUIL NGT TO CWA IN WAKE OF COLD FNT NOW MOVG SE INTO NRN LWR MI. RATHER DRY AIR UNDER HI PRES PER LOCAL 00Z RAOBS AND SFC DWPTS AS LO AS 7 AT YQT. BUT SOME PTCHY SC EVIDENT...MAINLY OVR THE NW AND THE S UNDER SUBSIDENCE INVRN ARND H9 AS DEPICTED ON 00Z GRB SDNG. SFC DWPTS IN THE 25 TO 30 RANGE JUST S OF CWA. 00Z MODELS IN FAIRLY GOOD AGREEMENT SHOWING INCRSGLY AMPLIFIED UPR PATTERN OVR THE CONUS DVLPG BY MID WEEK AS WRN TROF DEEPENS/ERN RDG BLDS IN RESPONSE TO HIER MOMENTUM DROPPING SWD INTO WRN TROF. MAIN FCST CONCERNS INTO TNGT ARE CLD/TEMP TRENDS...AND THEN PCPN CHCS BEGINNING LATE TNGT INTO THU AS SHRTWVS LIFTING OUT OF WRN TROF WORK NE AND GRDLY ADVCT HIER MSTR BACK NWD. FOR TDAY INTO TNGT...UPR HGTS BLD OVR THE GRT LKS AS SFC HI SHIFTS TO THE E AND CO SHRTWV LIFTING NE GRDLY LWRS PRES ACRS THE NRN PLAINS...WITH 1009MB SFC LO REACHING NR INL BY 12Z WED. ALTHOUGH BOTH ETA AND AVN GET TO THIS SAME SOLN...PREFER MORE CONSISTENT AVN HANDLING OF PRES FIELD AS STEADY...SLOWER FALL IN PRES MORE CONSISTENT WITH XPCTD SHEARING OF SHRTWV LIFTING NE FM MEAN TROF POSITION. SSELY FLOW OVR CWA GRDLY INCRSES AS PRES GRADIENT SHARPENS BTWN DEPARTING HI AND FALLING PRES OVR THE NRN PLAINS. DESPITE INCRSG ISENTROPIC LIFT AND APRNT WARM FROPA TDAY...AIRMASS INITIALLY SO DRY THERE WL BE NO SYNOPTIC SCALE PCPN UNDER JUST SOME HI CLD. FCST QUESTION FOR TDAY IS WHETHER THERE WL BE ANY SC AHD OF WARM FROPA. BOTH AVN AND ETA SHOW HIER SFC DWPTS POOLING ALG DSPTG COLD FNT DROPPING S OF CWA...PRESENCE OF SC CIG ACRS SRN TIER AND SE OF CWA AT 06Z MAY BE INDICATIVE OF THIS PROCESS...AND RETURNING TO MAINLY THE ECNTRL ZNS TDAY BEFORE WARM FNT SHIFTS TO THE N TOWARD EVNG. FCST H100-85 THKNS AND UPSTREAM OBS WELL INTO THE 40S OVR WI YDAY SUG MAX TEMPS TOWARD HIER MAV GUIDANCE...ESPECIALLY IN THOSE PLACES THAT SEE THE MOST SUNSHINE OVR THE W. MODELS SHOW INCRSG H4-2 DVGC/H7-3 QVECTOR CNVGC OVR THE WRN HALF OF CWA OVRNGT AS RRQ OF STRENGTHENING WAD H3 JET IN ONTARIO GETS POSITIONED OVR NW GRT LKS. AVN/NGM GENERATE PCPN AS FAR E AS NW WI BY 12Z WED...BUT ETA ACTUALLY SHOWS LGT QPF OVR WRN ZNS LATE TNGT. CONSIDERING SOURCE AIRMASS IS SO DRY...WITH H85 DWPT DEPS/SFC DWPT AT 20 TO 30C/20 TO 25F RESPECTIVELY...AND FVRD AVN LWRS PRES SLOWER OVR NRN PLAINS (WITH WEAKER SLY FLOW/MSTR ADVCTN)...WL MAINTAIN DRY FCST AND JUST MENTION INCRSG CLDS OVR W TO PCLDY OVR THE E. AVN INDICATES SHARP PRES GRADIENT WITH 20 TO 25 KT SFC S WND ALL NGT IN WARM SECTOR. ASSOCIATED MECHANICAL MIXING AND AT LEAST PCLDY SKIES WL RESULT IN MINIMAL DIURNAL COOLING...MOS FCST MINS RSNBL. ON WED...AVN INDICATES SFC LO WL MOVE INTO CNTRL ONTARIO...WITH SWLY FLOW CONTG OVR CWA AHD OF APRCHG ATTENDANT COLD FNT...WHICH APPEARS TO REACH IWD TOWARD 00Z THU. H4-2 DVGC AND H7-3 QVECTOR CNVGC IN RRQ OF UPR JET PULL NE WITH UPR JET DURG THE MRNG...LEAVING THE CWA IN INCRSGLY MOIST SW FLOW BUT WITH NO DYNAMICS AND WEAK ISENTROPIC LIFT. WL COLOR THE DAY MOCLDY...AND CONT WITH CHCY POPS DVLPG W TO E ALL ZNS AS AVN GENERATES SOME LGT QPF ENTIRE FA. HAVE OPTED TO GO WITH JUST RA XCPT OVR FAR W AFTR MILD OVRNGT AND PER AVN FCST H100-H85 THKNS/SFC DWPT AOA 1305M/32F AND FWC/MAV FCST PCPN TYPE. MOS FCST MAX RSNBL AND WELL ABV NORMAL. MODEL SOLNS BEGIN TO DIVERGE EVEN MORE SO ON WED NGT. AVN HAS REMAINED CONSISTENT SHOWING A STRGR SRN BRANCH SHRTWV LIFTING NE AND CAUSING A DEEPER SFC LO TO DVLP ON BAROCLINIC ZN SW OF CWA WED NGT AND THEN TAKING DEEPER LO NE TOWARD ERN ZNS WITH WDSPRD PCPN OVR ALL BUT THE FAR W. ETA AND NGM HAVE TRENDED TOWARD EARLIER CANADIAN SOLN OF A BIT STRGR NRN SHRTWV/DRY PUSH BEHIND INITIAL LO PRES...THAT FORCES BAROCLINIC ZN AND A WEAKER/MORE SHRD SFC LO FARTHER E SO THAT CWA WOULD MISS MOST PCPN. 12Z ECMWF SHOWED A DEEP 995 MB LO MOVG ACRS CNTRL ZNS THU MRNG. 00Z UKMET VERY MUCH SUPPORTS AVN SOLN. SINCE MODELS SHOW MAJORITY OF WRN TROF LIFTING NE...FEEL THE IDEA OF A STRGR SRN SYS IS THE BEST SOLN. ALSO GIVEN PERSISTENCE OF ERN RDG...FEEL THE FARTHER W IDEA IS THE WAY TO GO. SINCE AVN IS CONSISTENT WITH THIS HYPOTHESIS...MIDDLE OF THE ROAD WITH RESPECT TO VARIOUS SOLNS...AND MOST CONSISTENT WITH GOING PACKAGE...WL STICK WITH ITS FCST ATTM. AVN SHOWS INCRSG H4-2 DVGC/H7-3 QVECTOR CNVGC IN LEFT EXIT OF LIFTING H3 JET MAX OVRSPRDG CWA WED NGT WITH CCB STRUCTURE ON CYC SIDE OF H5 VORT MAX TRACK DVLPG THU MRNG AS UPR DYNAMICS BEGIN TO PULL NE. STRG DYNAMICS AND FCST H85-7 FRONTOGEN IN DEFORMATION ZN TO THE W OF SFC LO TRACK SUGS ANY MIXED PCPN WL CHG TO ALL SN ACRS THE W AND CNTRL ZNS (W OF H85 LO TRACK) WITH A MIX OF SN/RA OVR THE E. AS SFC LO LIFTS INTO ONTARIO THU AFTN...AVN SUGS STRG NW WNDS WL DVLP ACRS CWA WITH LES DVLPG IN CYC FLOW BEHIND SYS (H85 TEMPS FALL NR -15C)...ESPECIALLY OVR WRN ZNS FVRD FOR NWLY FLOW. NECESSARY CHGS TO GOING PACKAGE INCLUDE BUMPING UP POPS ON WED NGT AND TRENDING TOWARD MORE RA ESPECIALLY WED NGT/EARLY THU OVR THE E. BUT WL NOT GET TOO WRAPPED UP IN DETAILS ATTM GIVEN THE GREAT UNCERTAINTY AND MAINTAIN GOING LIKELY POPS. COORDINATED WITH APX/GRB. .MQT...NONE. KC mi SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 306 AM CDT TUE DEC 11 2001 ...FORECAST CHALLENGES ABOUND WITH WIND TDA AND PCPN IN 3RD PERIOD... 00Z SUBJECTIVE ANALYSIS AND WATER VAPOR IMAGERY PAINT BROAD TROUGH OVER WESTERN UTAH WITH A SERIES OF SEVERAL UPSTREAM WAVES IN THE FLOW OVER THE PACIFIC NW. NLY JET OF 90KTS CONTS TO DRIVE ENERGY INTO TROUGH...PROHIBITING ANY EASTWARD PROPAGATION. CLOSER TO THE SURFACE...VORT CENTER STRETCHING NE OUT OF COLORADO FOLLOWED BY SURFACE LOW OVER SE WYOMING WITH GRADIENT TIGHTENING UP AS OBSERVED BY 35KT/500METER ON 07Z NLG PROFILER. IN NEAR TERM...WIND SPEEDS CAPTURE ATTN BUT AFTER MULLING OVER RUC40 GUST SPEED LOOKS LIKE MIDLEVEL MOISTURE WILL LIMIT POTENTIAL UNDER ADVISORY CRITERIA WITH STRONGEST GUSTS OF 30KT OVER SE CWA. MESOETA IN AGREEMENT WITH STIFF H85 AT 50KT DROPPING OFF AFTER 18Z IN THE PRESENCE OF MODERATE CLOUD COVER. THE CLINCHER TO THE FCST IN THIS PATTERN IS THE IMPACT THE SHORTWAVES OFF COAST WILL HAVE WITH THIS AND SUBSEQUENT SYSTEMS AS THEY WILL BE INCLINED TO LAG WESTWARD INTO THE STAGNANT BROAD WESTERN TROUGH...THUS PREVENTING THE INFILTRATION OF THE H5 -30C AIR SITUATED ALONG THE CANADIAN BORDER AND THE -28C AIR OVER NRN ARIZONA THAT HAS ESTABLISHED THE LOW AS COLD CORE. ETA HAS BEEN CATCHING ONTO THESE EFFECTS BEST AND WILL GENERALLY STICK TO SOLN FOR TIMING AND PLACEMENT OF PCPN ON WED. AFOREMENTIONED WAVE WILL EJECT OUT OF SW DURING NEXT 24 HRS. HUGE DIFFERENCES BETWEEN 12Z AND 00Z RUNS LIE IN THE PLACEMENT OF THE QPF FIELD AND CONSIDERABLE UNCERTAINTY REMAINS BASED UPON RECENT PERFORMANCE OR LACK THEREOF. H7 LOW TRACKING NE FROM DDC INTO GID KS ZONES FROM 06Z WED TO 06Z THURS WOULD PLACE FAIR SHOT IN WRAPPED PORTION OF SYSTEM AS SFC CENTROID MAKES BEELINE FOR LAKES THEREAFTER. ISENTROPIC ANALYSIS ON 295K SFC SHOWS BEST LIFT ALONG SW TO NE ORIENTED AXIS THRU HSI WITH MIX RATIOS ON ORDER OF 3-4 G/KG. AVN AND ETA PROG SOUNDINGS ALSO SHOW FAVORABLE PROFILES THRU LAYER WITH ONLY FLY A VERY SHALLOW WM LAYER OVR KS ZONES FROM 12-18Z. MIDLEVEL LAPSE RATES SUGGEST POSSIBLE CONVECTIVE ENHANCEMENT FOR SN. NEXT CHALLENGE AWAITS FOR SIMILAR SITUATION TO UNFOLD DURING WEEKEND TIME FRAME. MODELS HAVE WAFFLED BETWEEN SAT-MON ON THIS WAVE...BUT NOW THAT WERE STARTING TO SEE PATTERN OF PROGRESSIVE BIAS WILL STRETCH ACROSS SUN-MON PERIODS FOR LACK OF CONTINUITY. COORDINATION WITH ADJACENT WFOS VIA CONF CALL. SPS WILL BE ISSUED WITH ZONE PACKAGE FOR WINTER WX POTENTIAL. .GID...NONE. 33 ne AREA FORECAST DISCUSSION - CORRECTED NATIONAL WEATHER SERVICE ALBANY NY 127 AM EST TUE DEC 11 2001 DISC... .BOTTOM LINE...ANOTHER MILD WEEK. .PROBLEM OF THE DAY...HOW LONG DO CLDS LINGER TDA AND ASSOCD MAXT? .SYNOPSIS...BIFURCATED ULVL CRCLN WRN NOAM CREATED BY DP TROAL OVR US ROCKIES. BROAD ULVL RDG CNTRL/ERN US. MINOR/WKNG SHORT WV MOVG EWD THRU MID ATLC RGN TMRNG. RUC SHOWS H2/H3 WMAX MOVG ACRS SNE W SOME QP MOVG NWD THRU MID ATLC RGN IN RR ENTRANCE AREA OF WMAX. AT SFC SPRAWLING HIPRES OFF NEW ENG CST MOVG FURTHER SEAWARD WHILE INVERTED TROF DVLPS ALG MID ALTC CST TMRNG...AND TRAILING SRN EDGE OF CDFNT MOVS SWD TO ST LAW VLY. WHOLE SYNOPTIC COMPLEX IS PROGRESSIVE...SO BY TEVE...SFC HIPRES RDG FCST TO SHFT INTO NY FM THE WEST AS CDFNT HANGS UP ACRS NRN NY/NEW ENG. MEANWHILE ULVL RDG BLDS STGLY OVR ERN NOAM. BLDG ULVL RDG ENHANCES SFC HIPRES CNTRD NR MOUTH OF ST LAW ERY WED AND COLD AIR DAMMING RDG IS FCST NEW ENG TO PIEDMONT AREA. SOME WEAK ISENTROPIC UPLIFT/INCRG RH SETTING UP OVR CWA WED...AS CREST OF ULVL RDG SHFTS OFF ATLC CST. .MDLS...AVN/ETA/META/RAFS/2 CNDN MDLS/MM5 SUNYSB EXAMINED FOR THE FCST. ALL MDLS BRUSH SRN FRINGE OF CWA W QP BFR 12Z...BUT ARE DRY TIL WED AFTN WHEN GEM RGNL/ETA/AVN/META GENERATE SPOTTY LGT QP S/E CWA. OTHER THAN AVN/CNDN MDLS MOVG SFC INVERTED TROF EWD MORE QUICKLY THAN OTHER MDLS...NOTICED NO SGFNT DIFFERENCES IN MDL FCSTS. NCEP FAVORS AVN. ALL MDLS ARE INCRG LLVL MSTR FM E/S CRCLN INTO NY/NEW ENG WED...BUT ULVL RMNS FAIRLY DRY. .SHORT TERM...SC CLDS XTSV IN SRN HLF OF CWA ATTM. MDL FCST SNDGS INDC DRYING ALL LVLS TDA...SO XPC SOME SS THRUT BY TAFTN. FWC/MAV MAXT CLOSE...SUNYSB SNDGS WHICH ARE USUALLY QUITE RELIABLE FOR MAXT WAY TOO COLD...SEEM TO BE HAVING TRBL W SNOW COVER. GEM BNDRY LYR...IN 30S N/W OF CAP DIST AT 18Z SUGGESTG MAXT WL BE LWR THAN MOS. PREV ZN FCST AGREES W CURRENT MOS AND SINCE CSDRBL SS SEEMS LKLY FOR A GOOD PORTION OF THE DAY...WL STICK W IT. SFC WND L/V TDA. .LONG TERM...MNLY SKC XPC TNGT AS HIPRES RDG TAKES HOLD. MIN/T MNLY 20S. E WND XPC TO PICK UP IN MHVLY AND XPC LTL HIR MIN/T THAN OTHER LOCS. L/V WND MOST ZNS TNGT. FOR TUE XPC LLVL CLDNS TO INCR. PREV ZNS HAS INDC THIS WELL AND WL ADHERE TO THE FCST. FWC POP 24 PCT AT KPOU FOR WED. SOME MDLS INDC SOME LGT PCPN. MAY INTRODUCE CHC DRZL SE. DON/T XPC MUCH DIFFERENCE IN MAXT FM TDA XPC MAXT/S. EVEN THO THKNS IS HIR...CLDS WL PRECLUDE FULL POTENTIAL OF HEATING FM BEING REALIZED. .XTND FCST...ULVL TROF SHFTG EWD AND WL BE TIED TO LOPRES MOVG THRU ERN CANADA/CDFNT MOVG TO OH VLY BY LT THU AND OFF ATLC CST BY LT FRI. HIPRES BLDS IN/OVR NERN US FOR THE WKEND. MOISTURE/QP FM SYS TO WEST BEGINS TO ENCROACH UPON ERN NY/WRN NEW ENG WED NGT. PREV ZNS HAD LKLY POPS. CURRENT MOS MNLY CHC. WL STICK W LKLY BASED ON QPF FM CNDN GLOBAL/AVN. ETA/META HAVE A MNLY DRY SOLTN. HWR... ISENTROPIC UPLIFT OF MOIST LLVL WUD SEEM TO ENSURE AT LEAST SOME LGT QP. MORE QP THU AS LOPRES MOVS TO VCNTY ERN GRTLKS AND CDFNT TO WRN NY LT. A WV ON THE FNT THREATEN QP FOR FRI TOO. PREV ZN FCST LOOKS OKAY INTO XTND PD AND WL MAKE NO CHGS. .ALY... NONE. KHH ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 218 AM EST TUE DEC 11 2001 SFC LOW LOCATED E OF MYR AS 05Z AND CONTINUING TO TRACK NNE. BULK OF THE PRECIPITATION OCCURRING N AND E OF THE LOW. ETA/AVN AND RUC-40 SHOWING BEST UVV AND H9-H8 MOISTURE FLUX BETWEEN NOW AND 12Z BEFORE DIMINISHING BY LATE MORNING. WILL BASE POPS ON RADAR...BUT CURRENT INCLINATION IS TO CARRY HI CHC TO LOW LIKELY POPS ALONG THE CST AND TAPER TO A CHC WELL INLAND WITH WORDING MAINLY FOR THE MORNING HOURS. EXPECT SKIES TO REMAIN CLOUDY FOR THE BULK OF THE DAY WITH POSSIBLY A FEW PEAKS OF SUN DURING THE AFTERNOON. TEMPS TRICKY FOR TODAY'S AFTERNOON HIGHS BEING HIGHLY DEPENDENT ON EXTENT OF CLOUD COVER. MAV/FWC CLUSTERED AROUND LOWER FIGURES WITH THE LOCAL ETA NUMBERS BEING A BIT WARMER. WILL USE A CONSENSUS BLEND OF THE THREE...WHICH SHOULD HIGHS INTO THE LOWER 60S MOST AREAS. CLOUD COVER ALSO TOUGH TO FIGURE TONIGHT AS WE ARE BETWEEN SYSTEMS. EXPECT SOME CLEARING...WHICH WILL LEAD TO SOME PATCHY FOG AND STRATUS. MINS A FEW DEGREES EITHER SIDE OF 50. FOR WEDS...MOISTURE A BIT MORE SHALLOW...BUT WITH NE FLOW WILL OPT FOR PTCLOUDY WITH MAXES IN THE LOWER TO MIDDLE 60S. IN THE LONGER TERM...STRONG COLDFRONT POISED TO PUSH THRU THURSDAY AS AVN SHOWING LARGE SWATH OF DEEP OMEGA. MARINE...AT 07Z A SFC LOW WAS S OF CAPE FEAR OVER OCEAN WATERS. IT APPEARS THE LOW WILL CONTINUE TO TRACK NE OVER WATER BUT POTENTIALLY CLIPPING LOOKOUT AND HATTERAS. THIS WILL SHIFT BLUSTERY SE WIND TO A N-NW COMPONENT THROUGH THE COURSE OF THE MORNING. SEAS ALREADY RUNNING 5 TO 6 FEET AND WILL KEEP SCA FLAGS POSTED FOR THE COASTAL WATERS. WILL ALLOW FLAGS TO DROP FOR THE SOUNDS SINCE MARGINAL WINDS WILL BE SHORT LIVED. INITIALIZATION OF WIND A LITTLE TRICKY BUT WILL COUNT ON A SFC LOW TRACK SKIRTING OUR COAST AND THEN MOVING OUT. .MHX...SCA FOR THE COASTAL WATERS. PUBLIC/FIRE...COLLINS MARINE/AVIATION...COLBY nc AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN NATIONAL WEATHER SERVICE ABERDEEN SD 325 AM CST TUE DEC 11 2001 NUMEROUS LITTLE PROBLEMS TO DEAL WITH THIS MORNING PACKAGE. STRONG LOW LIFTING OUT NOT INITIALIZED WELL IN THE MODLES...WITH ALL OF THEM UNDERESTIMATING THE STRENGTH OF THE LOW. LATEST RUC SEEMS TO BE DOING OK AND WILL USE THIS IN THE VERY NEAR TERM. WARM FRONT LIFTING NORTH THROUGH ERN SD...WITH TEMPS CLIMBING IN ERN NEB AND SERN SD. BAND OF LOW CLOUDS ALSO LIFTING NORTH WITH WARM FRONT. AFTER WARM FRONT LIFTS NORTH THROUGH ERN CWA BY 18Z...WILL THERE BE SOME BREAKS IN THE CLOUD COVER OR NOT. LOOKING AT WATER VAPOR LOOP AND CONFIRMING WITH MODELS...STRONG JET CORE SHOULD PASS OVER ERN CWA DURING DAY TODAY. WITH 7H AND 8H REMAINING DRY FOR BETTER PART OF DAY ACROSS ERN CWA...BELIEVE THAT A FEW BREAKS WILL DEVELOP FROM KABR AND EAST...THOUGH PROBABLY WON'T GO MOSUNNY WITH HIGH CLOUDS STREAMING IN. ALSO...WITH SUCH STRONG WAA TAKING PLACE TODAY...TEMPS COULD BE TRICKY. WITH TEMPS ALREADY RISING ALONG I-29 CORRIDOR...AM TEMPTED TO BUMP UP TEMPS 5 OR SO DEGREES ABOVE GUIDANCE. HOWEVER...WITH BKN-OVC HIGH CLOUDS...WILL BE CONSERVATIVE AND LET DAY SHIFT RATCHET UP TEMPS IF THEY NEED TO. ANOTHER CONCERN IS WHEN COLD FRONT WILL PASS THROUGH WRN CWA TODAY. AS SFC LOW LIFTS NORTH AND GETS STRETCHED...COLD FRONT SHOULD PASS THROUGH MO RIVER COUNTIES AROUND 18Z...TURNING WINDS TO THE WEST...THEN NORTHWEST. WITH LOW CLOUDS ALREADY IN THE WEST...DON'T FORSEE MUCH MORE WARMING DURING MORNING...SO WILL GO STEADY TEMPS THERE. WITH MAIN DYNAMICS OF SYSTEM PASSING ACROSS THE WRN CWA...WILL INCLUDE SOME 20 POPS FOR LIGHT SNOW...BUT REMOVE FOR THE ERN CWA. JUST DON'T SEE ENOUGH MOISTURE TO WRING OUT. DID NOTICE THAT ON THE 290K SFC...2 G/KG SPEC HUMIDITES DO MOVE INTO THE I-29 CORRIDOR AREA LATE THIS AFTN AND INTO THE EVENING...BUT THAT IS AFTER BEST LIFT HAS PASSED. BELIEVE THAT IT MAY BE MORE WRAPAROUND MOIST FOLLOWING COLD FRONT. FOR WEDNESDAY...MUCH COOLER DAY IN STORE WITH CAA AND CLOUDS. FOR THURSDAY...NEXT 5H WAVE DROPS INTO CWA. LOOKING AT SPEC HUMIDITY PLOTS...NOT MOISTURE WITH THIS ONE AS WELL...ALTHO HUMIDITY IMAGES ARE QUITE SATURATED...BUT THAT IS PROBABLY MORE INDICATIVE OF TEMPS THAN ACTUALL MOISTURE CONTENT. DIDN'T FIDDLE MUCH WITH EXTENDED FORECAST. .ABR...NONE. HINTZ sd TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO, TX 320 AM CST TUE DEC 11 2001 CURRENT FORECAST DIFFICULTIES INCLUDE THE TIMING AND EXTENT OF PRECIPITATION TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING. SURFACE ANALYSIS SHOWED A LEE TROUGH IN PLACE WITH DECENT LOW-LEVEL MOISTURE AROUND MIDLAND AND ABILENE. THIS MOISTURE WILL BEGIN MOVING NORTH TODAY. THE LEE TROUGH WILL KEEP WINDS SOUTHERLY REACHING THE BREEZY CATEGORY BY AFTERNOON. AN UPPER-TROUGH WILL MOVE INTO ARIZONA WITH A VORT MAX PUSHING INTO EASTCENTRAL NEW MEXICO BY LATE AFTERNOON. A SLIGHT CHANCE OF RAIN WILL BE POSSIBLE AS THIS FEATURE APPROACHES THE TEXAS PANHANDLE EARLY THIS EVENING. THE TIMING WILL DEPEND ON HOW FAST LOW-LEVEL MOISTURE RETURNS THIS AFTERNOON. THE ETA/AVN SOLUTION BREAKS PRECIPITATION OUT BY LATE AFTERNOON HOWEVER...THE LATEST RUC APPEARS LESS AGGRESSIVE AND SLOWER. WILL PROBABLY LEAVE A SLIGHT CHANCE OF RAIN OUT FOR THIS AFTERNOON BUT WILL WAIT TO CHECK OUT THE NEWEST RUC AT 09Z. THE NEW MESOETA IS SLOWER AND LESS AGGRESSIVE AND THIS MODEL SEEMS BEST. HOWEVER... AS THE DISTURBANCE APPROACHES VERY LIGHT RAIN WILL BE POSSIBLE WITH THE BEST CHANCE IN THE EAST TONIGHT. IF WE HAVE ANY PRECIPITATION AT ALL FROM THIS SYSTEM...A CHANGEOVER TO LIGHT SNOW MAY OCCUR AFTER MIDNIGHT ESPECIALLY IN THE WESTERN AND NORTHERN ZONES. A COLD FRONT WILL PUSH DOWN ACROSS THE AREA WEDNESDAY WITH COLD AIR ADVECTION TO FOLLOW. IT APPEARS THAT THURSDAY TEMPERATURES SHOULD BE ABOUT THE SAME AS WEDNESDAY ESPECIALLY IF THE FRONT LINGERS AT ALL ON WEDNESDAY. THIS IS ALSO REFLECTED BY THE MAV SO WILL LOWER TEMPERATURES A BIT FOR THURSDAY. FOR THE LATER PERIODS...ANOTHER LONGWAVE TROUGH WILL DEVELOP BEHIND THE EXITING TROUGH THURSDAY NIGHT AS SHOWN BY THE MRF AND ECMWF. HOWEVER...THE MRF AGAIN LOOKS TO FAST WITH THIS SYSTEM. A COLD FRONT ASSOCIATED WITH THE UPPER-TROUGH SHOULD COME THROUGH SATURDAY NIGHT WITH A MUCH COOLER DAY ON SUNDAY AS THE HIGH SHOULD HAVE CANADIAN AIR WITH IT. WILL KNOCK TEMPERATURES DOWN A BIT ON SUNDAY. AFTER TROUGH PASSAGE SUNDAY NIGHT...A LEE TROUGH AND WARMER TEMPERATURES MAY RETURN TO THE AREA. PRELIM CCF... AMA 58/30 44/22 46 -12 DHT 53/25 41/19 42 -12 .AMA... OK...NONE. TX...NONE. CB tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1120 AM EST TUE DEC 11 2001 MAIN FCST CONCERNS THIS AFTERNOON ARE CLOUDS/TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED SW FLOW TOWARD THE WRN GRT LAKES AHEAD OF TROF OVER THE ROCKIES. A SHRTWV OVER THE CNTRL DAKOTAS WAS BECOMING INCREASINGLY SHEARED AS IT APPROACHED FLAT H5 RDG AXIS EXTENDING FROM SRN MANITOBA TOWARD NRN WI. AT THE SFC...DEPARTING RDG EXTENDED FROM ERN ONTARIO TO OHIO AND THE ERN LAKES WHILE A TROF WAS DEVELOPING OVER THE HIGH PLAINS. 280K ISENTROPIC LIFT AHEAD OF A WARM FRONT INTO SE MN AND SW WI SUPPORTED A PATCH OF SC OVER CNTRL AND WRN UPR MI...PER VIS LOOP. 12Z KGR AND FCST SNDGS INDICATED A RELATIVELY SHALLOW MOIST LYR BLO STRONG 900 MB INVERSION. 12Z RUC/ETA AND SATELLITE TRENDS SUGGEST CLD LYR WILL CONTINUE TO THIN OUT AND LIFT TO THE NORTH. SOME HI CLD OVER NE MN AND NW WI MAY ALSO GRAZE WRN UPR MI. SO...WL MAINTAIN GOING FCST WORDING OF PTSUNNY CNTRL AND WEST BUT MENTION MOSTLY SUNNY OVER THE ERN CWA. WITH TEMPS ALREADY INTO THE MID AND UPPER 30S F AND INCREASING SUNSHINE EXPECTED BY 19Z...CURRENT FCST MAX IN THE 40-45 RANGE LOOKS ON TRACK. .MQT...NONE. JLB mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1039 AM EST TUE DEC 11 2001 THE 15Z SURFACE PLOT SHOWS A WEAK TROUGH EXTENDING FROM SOUTHERN LAKE HURON TO KMKG. TRENDS IN THE SURFACE ANALYSIS AND LATEST RUC CONTINUE TO WASH THIS FRONTAL BOUNDARY OUT ACROSS THE AREA THIS AFTERNOON AS HIGH PRESSURE NORTH OF LAKE HURON SLIDES EAST INTO QUEBEC. SCATTERED STRATO CU CLOUDS ARE NOTED ON THE 11-3.9U AND CURRENT VIS IMAGE OVER CENTRAL/SOUTHERN LAKE HURON. INCREASING SOUTHEAST FLOW IN THE LOW LEVELS THIS AFTERNOON SHOULD CONTINUE TO BRING SOME OF THESE CLOUDS INTO HURON AND SANILAC COUNTIES EARLY (BEFORE SUBSTANTIAL DRYING OCCURS IN THE BOUNDARY LAYER). QUITE A BIT OF CIRRUS NOTED ACROSS ILLINOIS AND CENTRAL INDIANA AHEAD OF A WEAK SHORTWAVE OVER NORTHEAST OK. SATELLITE TRENDS AND RUC/MESO ETA SUGGEST THAT THESE WILL PUSH JUST WEST OF THE FORECAST AREA. THUS I WILL CONTINUE THE SUNNY FORECAST ACROSS THE CWA (OUTSIDE OF THE THUMB). CURRENT FCST MAX HIGHS LOOK IN LINE WITH LATEST GUIDANCE AND TRENDS. THUS ONLY CHANGES TO ZONES WILL BE TO DROP MORNING WORDING. .DTX...NONE. CONSIDINE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1025 AM EST TUE DEC 10 2001 ...QUICK UPDATE TO REMOVE MORNING WORDING... SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE IN CONTROL OF OUR WEATHER. LOW PRESSURE SYSTEM THAT BROUGHT RAIN TO SOUTHERN PA LAST NIGHT LOCATED OFF VIRGINIA COAST. NEXT FRONTAL SYSTEM LOCATED WELL OFF TO OUR NORTH AND WEST. WEAKENING VORT SPINNING IN CENTRAL VIRGINIA STILL SUPPLYING A FEW CLOUDS OVER SOUTHEAST PA. AS THIS VORT TRAVERSES EASTWARD TODAY AND WEAKENS FURTHER...AREA OF CLOUDINESS WILL ADVECT SOUTHWARD ONCE AGAIN. SUNNY TO MOSTLY SUNNY SKIES EXPECTED ACROSS THE OLE FORECAST AREA TODAY. RUC CROSS SECTIONS SHOW MIXING GENERALLY REACHING TO ABOUT 900 MB. MIXING THE 5 C AIR DOWN TRANSLATES TO MAX TEMPS OF 50-53 FOR THE AVERAGE ELEVATION. LIGHT NORTHEAST BREEZES MAY TRANSLATE DOWN TO THE SURFACE EXCEPT CLOSER TO THE LOW WILL GO WITH SLIGHTLY STRONGER NORTH WINDS. WORK ZONES OUT IN A BIT...REAL ZONES ON THE STREETS SHORTLY THEREAFTER! .CTP...NONE. ROGOWSKI/MARTIN pa AREA FORECAST DISCUSSION...UPDATED... NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 630 AM EST TUE DEC 11 2001 FORECAST AREA IS ENTRENCHED IN A COLD AIR DAMMING WEDGE THIS MORNING. PATCHY FOG SHOULD LINGER ACROSS THE WESTERN CAROLINAS THROUGH THE MID MORNING...AND MAY PERSIST UNTIL THE MIDDLE PART OF THE DAY ACROSS THE NC FOOTHILLS/NW PIEDMONT. WILL REMOVE DRIZZLE FROM NC FOOTHILLS/NW PIEDMONT SINCE THE SUPPORT FOR IT HAS MOVED EASTWARD. HAVE DECIDED TO TWEAK THE ZONES THIS MORNING BASED ON A HOLE THAT HAS OPENED IN THE LOW OVERCAST...APPARENTLY DUE TO SOME WEAK DOWNSLOPE OFF THE EASTERN ESCARPMENT OWING TO LIGHT NW FLOW AT 850 MB SEEN IN THE LATEST RUC. THIS FEATURE SHOULD BE TRANSIENT THIS MORNING AND THE LOW CLOUDS WILL PROBABLY FILL IN AS THE COLD DOME DRAINS. NEVERTHELESS...THINK IT A GOOD IDEA TO OPEN UP A BIT OF A RANGE ACROSS THE UPSTATE ZONES AND TO BUMP THE ABBEVILLE/GREENWOOD AREA TO MID 50S. THE MAIN FORECAST PROBLEM IS WHEN TO UNWEDGE. THE PREVAILING THINKING STILL IS THAT TODAY HOLDS LITTLE CHANCE OF COMPLETELY SCOURING OUT THE COLD AIR DOME...EVEN THOUGH IT SHOULD DRAIN A BIT EARLY IN THE DAY...AS HIGH PRESSURE MOVING INTO EASTERN CANADA REINFORCES THE NE FLOW BY THIS AFTERNOON. TEMPS SHOULD NOT REBOUND MUCH TODAY UNDER EXTENSIVE LOW CLOUD COVER ACROSS THE NC PIEDMONT. FOR NOW...WILL KEEP TEMPS VERY CLOSE TO PREVIOUS FORECAST (WHICH IS BELOW GUIDANCE) ACROSS THE DAMMING REGION E OF THE MOUNTAINS...WITH THE AFOREMENTIONED CHANGES OUTLINED ABOVE. TEMPS SHOULD ACTUALLY BE WARMEST ACROSS THE MOUNTAINS THIS AFTERNOON AS SOME LOCATIONS SHOULD SEE A BIT OF SUN BY THE END OF THE DAY. FOR TONIGHT...CLOUDS CONTINUE AND FOG SHOULD REDEVELOP IN THE EARLY MORNING HOURS WEDNESDAY. WEDNESDAY IS THE TRICKY DAY AS THE MODELS TRY TO DESTROY THE WEDGE. LOW LEVEL MOISTURE WILL REMAIN PLENTIFUL WHICH SHOULD KEEP PLENTY OF CLOUDS IN THE AREA. WARM ADVECTION AT 850 MB AND ISENTROPIC LIFT MOVE BACK IN BY THE AFTERNOON. MEANWHILE...LOW LEVEL FLOW BEGINS TO VEER AROUND AHEAD OF THE NEXT FRONT AND AS HIGH PRESSURE MOVES OVER THE CANADIAN MARITIMES. I REMAIN HIGHLY SKEPTICAL THAT THE WEDGE WILL BREAK WEDNESDAY ACROSS THE FOOTHILLS GIVEN THE LACK OF GOOD SCOURING. WILL KEEP HIGH TEMPS BELOW GUIDANCE ACROSS MOST OF THE REGION...BUT WILL SPLIT OFF SOUTHEASTERN EDGE ZONES TO ACCOUNT FOR THE EDGE OF THE COOL POOL ERODING NORTHWESTWARD BY LATE IN THE DAY. THE LATEST RUNS OF THE AVN AND CANADIAN ARE IN AGREEMENT WITH DELAYING THE ARRIVAL OF THE NEXT SYSTEM UNTIL LATE WEDNESDAY NIGHT AND THURSDAY...AND PUSHING THE MAIN PRECIP EVENT BACK INTO THURSDAY NIGHT. THIS WILL FORCE SOME CHANGES TO THE EARLY PART OF THE EXTENDED...MAINLY THE ADDITION OF PRECIP TO THURSDAY NIGHT AND THE FIRST PART OF FRIDAY. TEMPS WILL ALSO HAVE TO BE BUMPED UP FIVE TO TEN DEGREES FOR THURSDAY NIGHT LOWS...AND ADJUSTED UPWARD A CATEGORY ON THE HIGHS FOR FRIDAY AND SATURDAY. NO OTHER CHANGES WILL BE MADE FOR THE LATE PART OF THE EXTENDED. FCSTID = 10 GSP 52 41 55 49 / 10 10 10 40 AND 53 41 56 49 / 10 10 10 40 CLT 51 41 54 49 / 10 10 10 30 HKY 49 38 50 47 / 10 10 10 40 AVL 53 38 55 47 / 10 10 20 40 .GSP... GA...NONE. NC...NONE. SC...NONE. MOORE sc COASTAL BEND FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1000 AM CST TUE DEC 11 2001 PACIFIC MOISTURE IN SW MEXICO CONTINUES TO SURGE NE INTO SOUTH TEXAS THIS MORNING. RR QUAD OF UPPER JET IS CURRENTLY OVER FA THIS MORNING. THIS IS HELPING TO PRODUCE ISENT LIFT OVER THE REGION...WHICH THE ETA AND RUC40 PROGS TO CONT THROUGH THIS AFTERNOON. MOST OF THE HEAVIER PRECIP SHOULD REMAINED FOCUSED IN NE ZONES IN VICINITY OF WARM FRONTAL BOUNDARY DEVELOPING ALONG THE COAST. WILL UPDATE ZONES TO INCREASE POPS FOR THIS AFTERNOON. .CRP...NONE. AP...72 SYN MB...80 MESO tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 830 AM PST TUE DEC 11 2001 .SYNOPSIS...A WEAK WEATHER SYSTEM WAS MOVING THROUGH WESTERN WASHINGTON THIS MORNING. A STRONGER FRONTAL SYSTEM WILL MOVE THROUGH THE REGION WEDNESDAY AFTERNOON AND NIGHT. AND A RATHER VIGOROUS SYSTEM WILL SWEEP THROUGH THE PACIFIC NORTHWEST LATER THURSDAY AND FRIDAY. .DISCUSSION...WK SHORTWAVE DROPS SE THRU WRN WA TDY...PROBABLY A WK CIRCULATION CENTER ALG THE COAST...THEN SE INTO ORE. SO SHOWING LGT SE WINDS BACKING TO NE. CURRENT RUC AND NEW ETA MATCH WELL PUTTING A WK SFC LOW AROUND KAST LATE THIS AFTERNOON. TEMPS NOW ARE A FEW DEGREES WARMER THAN I HAD THOUGHT YDY...SO WILL ADD A FEW DEGREES TO THE HIGHS AND MAY DROP THE LCL WET SNOW MOST ZONES UNLESS SOMETHING STARTS SHOWING UP IN THE OBS. STILL PRETTY COOL...SEEMS LIKE H850 HAS BEEN STUCK ON -4C OVR THE CASCDS RECENTLY...HOWEVER THE FNTL SYS WED EVENING TAKES THE 0C ISOTHERM WELL N THRU THE CASCDS W/ +3C FOR THE OLYMPICS. A RISING SNOW LEVEL THRU WED NITE...THEN BACK DOWN A NOTCH BEFORE RISING AGAIN LATE THU W/ THE NEXT MUCH STRONGER SYSTEM. A FEW ADJUSTMENTS THERE AS WELL...BUT MAIN THEME IS RATHER WET...SO MANY WAYS TO SAY RAINY, HEH. 06Z AVN SHOWED 999MB SFC LOW NR VICTORIA 12Z THU...WHILE THE NEW ETA TRACKS THE LOW CENTER TRACKING JUST N VRISL ABOUT SIX HOURS EARLIER...WED EVENING. MERELY BREEZY WED NITE AND THU LOOKS LIKE A GOOD FCST FOR NOW. McFarland UIL 757 SEA 757 OLM 757 .SEW...SMALL CRAFT ADVISORY COAST AND ENTRANCES TO THE STRAIT. .KATX...VCP21/CSR21...OPERATIONAL. wa SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 315 PM MST TUE DEC 11 2001 .SYNOPSIS... A COLD LOW PRESSURE AREA MOVING ACROSS THE REGION WILL BRING SHOWERS ...BREEZINESS AND VERY COOL TEMPERATURES TO SOUTH CENTRAL ARIZONA THIS EVENING. SOME ACCUMULATING SNOW IS EXPECTED AT AND ABOVE 4000 FEET. SKIES WILL GRADUALLY CLEAR FROM WEST TO EAST OVERNIGHT...AND TEMPERATURES WILL BE RATHER COLD. A WEAK WEATHER DISTURBANCE WILL BRING A SLIGHT CHANCE FOR A SHOWER TO SOUTH-CENTRAL ARIZONA WEDNESDAY...WITH THE BEST CHANCE OVER THE HIGHER TERRAIN. COLDER NIGHTTIME LOWS ARE EXPECTED WEDNESDAY NIGHT...WITH SIMILAR LOW TEMPERATURES LIKELY THURSDAY NIGHT. ANOTHER WEATHER DISTURBANCE WILL BRING CLOUDS AND A CHANCE FOR MAINLY LIGHT SHOWERS FRIDAY NIGHT AND SATURDAY. TEMPERATURES ARE EXPECTED TO WARM TO NEAR OR SLIGHTLY ABOVE NORMAL BY EARLY NEXT WEEK. .DISCUSSION... RUC PEGS LOWEST 500 MB HEIGHT AT 5430 M JUST EAST OF YUMA...AND WITH 115 KT 300 MB JET STILL ON ITS BACKSIDE...EXPECT LOW TO MOVE TOWARD THE ESE THIS AFTERNOON AND EVENING. PRECIP ENDING UPSTREAM AND NEAR LOW...WITH MOST ACTION OCCURRING OVER SOUTH CENTRAL AZ PTN OF CWA ATTM. EXPECT PRECIP TO GRADUALLY TAPER OFF AND END FROM WEST TO EAST ACROSS SOUTH-CENTRAL AZ THIS EVENING...BUT KEPT RATHER HIGH POPS IN FOR EXPECTED EARLY EVENING ACTION OVER PHX AND CENTRAL DESERT...AND WENT WITH CATEGORICAL POP OVER NE MARICOPA AND SOUTHERN GILA COUNTIES THIS EVENING WHERE HEAVY SNOW WARNING REMAINS IN EFFECT UNTIL 7 PM. AS STATED THIS MORNING...CWA OBVIOUSLY IN GRIP OF ANOMALOUSLY COOL AIRMASS. 3 PM TEMP AT PHX WAS ONLY 46 DEGREES...AND THIS TEMP IS REPRESENTATIVE OF S-CNTRL AZ DESERT TEMPS. THE HIGH OF 49 AT PHX WILL BE 17 DEGREES BELOW NORMAL FOR THE DATE. A BIT WARMER OVER FAR SOUTHEAST CALIFORNIA AND ALONG LOWER COLORADO RIVER WHERE SKIES HAVE ALREADY BEGUN TO CLEAR...BUT EVEN OUT THERE TEMPS ARE WELL BELOW NORMAL...MAINLY IN THE MID 50S. COOLER TONIGHT...BUT WITH DEW POINTS ELEVATED AS THEY ARE...MIN TEMPS WON'T BE AS COLD AS WHAT WILL OCCUR THE FOLLOWING COUPLE OF NIGHTS. POSSIBILITY FOR SOME PATCHY GROUND FOG MAINLY OVER S-CNTRL AZ LATE TONIGHT AND EARLY WEDNESDAY. ETA/AVN/MRF IN EXCELLENT AGREEMENT THAT WE WILL STAY QUITE COOL THE NEXT COUPLE OF DAYS. CANNOT ARGUE WITH THAT BASED ON LONG WAVE PATTERN AND FORECAST LOW LEVEL TEMPS. QUICK MOVING DISTURBANCE WILL MOVE SOUTHEAST ACROSS CWA WEDNESDAY AND PROVIDE ENOUGH LIFT TO WARRANT A SLIGHT CHANCE FOR A LIGHT SHOWER OVER S-CNTRL AZ...WITH A BETTER CHANCE OVER THE HIGHER TERRAIN WHERE A BIT MORE SNOW COULD FALL MAINLY ABOVE 4500 FOOT LEVEL. IN WAKE OF THIS DISTURBANCE...EXPECT THE COLDEST NIGHTS SO FAR THIS MONTH WEDNESDAY NIGHT AND THURSDAY NIGHT...WITH POTENTIAL FOR FROST AS WELL AS FREEZING TEMPERATURES OVER MUCH OF THE WEST-CENTRAL AND SOUTH -CENTRAL DESERT (DOWNTOWN PHX COULD LOWER TO 36 DEGREES BOTH NIGHTS). SOME MODERATION IN TEMPS LIKELY BY FRIDAY...AND MILDER FRIDAY NIGHT...BUT SHOWER CHANCE WILL BE UPON US AS ANOTHER DISTURBANCE TRACKS TOWARD THE ESE ACROSS THE FORECAST AREA. IN WAKE OF THIS DISTURBANCE...UPPER FLOW AMPLIFIES...LEADS TO SFC HIGH FORMATION TO OUR NORTH...AND WILL LIKELY RESULT IN BREEZY TO WINDY CONDITIONS AND COOL CONDITIONS SUNDAY. DRY WITH WARMER TEMPS EXPECTED MON-TUES AS SHORT WAVE RIDGE MOVES ACROSS AREA. 500 MB HEIGHTS EXPECTED TO BE WELL ABOVE NORMAL BY THAT TIME...BUT WILL ONLY MOVE TEMPS TO SLIGHTLY ABOVE NORMAL LEVELS SINCE LOW LEVELS WILL BE SLOW TO WARM UNDER WEAK WIND CONDITIONS. DG .PSR...HEAVY SNOW WARNING ABOVE 4000 FEET FOR AZ ZONE 24 UNTIL 7 PM TONIGHT. az FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 1020 AM CST TUE DEC 11 2001 WILL NEED TO UPDATE ZFP FOR TEMPS AND PCPN WORDING TODAY. A CONTRAST IN WEATHER ACROSS THE CWFA THIS MORNING. LOW CLOUD IMAGERY SHOWS A LARGE AREA OF LOW CLOUDS...FOG AND FREEZING DRIZZLE OVER CNTRL ND...WITH ERN EDGE FROM JUST EAST OF JAMESTTOWN TO NEAR LAKOTA. MOVEMENT HAS AREA MOVING NORTH-NORTHEAST. BIS SOUNDING SHOWS GOOD FZDZ POTENTIAL AT 12Z WITH MOIST VERY LOW LEVELS AND VERY DRY AIR ABV 900 MB. SFC LOW THIS MORNING NEAR PIERRE WITH ANOTHER WK LOW IN NW SD. APPARENT WARM FRONT LOCATED FROM SFC LOW TO NR GFK THEN TO NR BDE. STRONG 85H INFLOW (30-40KT FROM UPPER AIR DATA) FLOWING THRU ERN SD/MN INTO AREA...OVERRUNNING WARM FRONT AND CAUSING LOW CLOUDS JUST WEST OF WARM FRONT IN CNTRL ND. STRONGEST PRESSURE FALLS OVER SE ND ATTM...BUT LIKE LOW TRACK FROM RUC SHOWING IT NR JAMESTOWN AT 21Z. THUS WITH THIS TRACK DONT LOOK FOR MUCH EASTWARD ADVANCEMENT OF LOW CLOUDS/FZDZ INTO ERN ND THIS AFTN...WITH EXPANSE MORE NORTHEAST TOWARD DEVILS LAKE/LANDGON. THUS WILL UPDATE FOR FZDZ DVL AREA AS DVL FCST SOUNDING VIA ETA SHOWS POTENTIAL FZDZ SOUNDING WITH LOW LEVEL MOISTURE AND DRY 850 AND ABV. POTENTIAL FOR FZDZ MAY ALSO PARTS OF NE ND...(JUST WEST AND NORTH OF GFK) BY LATE TODAY. NO ADVISORY ANTICIPATED ATTM...BUT WILL NEED TO WATCH CAREFULLY. THERE SHOULD BE SOME MOISTENING IN THE 850-500 LAYER LATE TODAY/THIS EVENING OVER DVL ZONE AND ALSO SOME 85H COOLING WHICH HOPEFULLY WILL ALLOW PCPN TO GO OVER TO MORE OF A LIGHT SNOW VS STAYING AS FZDZ. WITH POSITION OF SFC LOW AND 85H TEMPS RISING TO ZERO TO PLUS 2 (FAR-GFK EAST INTO MN) WILL NEED TO ADJUST HIGHS TEMPS ABOUT 5 TO IN SOME CASES 10 DEGREES UPWARD VALLEY EAST. ALSO WILL UPDATED SKY COVER WORDING FOR MORE SUN EAST OF LOW. .FGF...NONE. RIDDLE nd