AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1030 PM EST THU DEC 27 2001 MAIN FCST CONCERNS AGAIN ARE LES TRENDS. WV IMAGERY AND RUC ANALYSIS INDICATED CLOSED H5 LO OVER ERN ONTARIO NEAR CYTS (TIMMONS). ONE SHRTWV SPOKE WAS LOCATED OVER NW WI WHILE NEXT SIGNIFICANT SHRTWV WAS LOCATED SW OF JAMES BAY NEAR CWNZ. AT THE SFC...LO PRES WAS LOCATED OVER SE LK SUPERIOR WITH A TROF EXTENDING WEST TOWARD THE KEWEENAW. IR LOOP INDICATED COLDER CLOUD TOPS WITH WI SHRTWV INTO WRN AND CNTRL UPR MI. LK-H8 DELTA/T REMAINED NEAR 20C WITH INVERSION HGTS ABV 8K FT. SO...LES MACHINE CONTINUES IN EARNEST. KMQT 88D SHOWED POTENT LES BAND FROM NEAR BIG BAY TO GRAND ISLAND AND PICTURED ROCKS JUST NE OF MUNISING...IN LINE WITH GREATEST LLVL CONVERGENCE SOUTH OF THE TROF...SAGGING ONLY SLOWLY TO THE SOUTH. SNOWFALL RATES WITH THIS FEATURE HAVE RANGED UP TO 3 INCHES PER HOUR NEAR MELSTRAND FROM ABOUT 00Z-01Z. EXPECT THE BAND TO EVENTUALLY SLIDE FARTHER SOUTH AND WEAKEN/DISSIPATE AS WINDS CONTINUE TO SLOWLY VEER AS WI SHRTWV MOVES SOUTHEAST AND WITH VEERING 850-500 WINDS AIDING LLVL WIND SHIFT. HOWEVER...TIL THAT OCCURS...HAVE POSTED LES ADVY FOR POSSIBILITY OF ADDITIONAL 2-6 INCHES AND OCNLY HEAVY SNOWFALL RATES. OVER THE WEST...WINDS HAVE VEERED CLOSER TO 330 WHICH HAS REDUCED THE FETCH AND ALLOWED SNOWFALL RATES TO DIMINISH...ESPECIALLY FOR THE KEWEENAW WHERE KCMX DID NOT REPORT ANY -SN AT 03Z. 00Z ETA CONTINUES TO SHOW GREATER LLVL CONVERGENCE FROM M-38 TOWARD KIWD. SO...WILL KEEP HEADLINES WITH ADDITIONAL OVERNIGHT SNOWFALL AMOUNTS UP TO ABOUT 6 INCHES. FARTHER INLAND...-SHSN HAVE DIMINISHED AS LIFT WITH SHRTWV HAS SHIFTED TO THE SOUTH AND EAST. SO...LITTLE ADDITIONAL -SHSN EXPECTED OVERNIGHT MORE THAN A PASSING FLURRY. .MQT...LAKE EFFECT SNOW WARNING TONIGHT INTO FRIDAY MIZ001>003-009. ...WINTER STORM WATCH FRIDAY AFTERNOON INTO SATURDAY MIZ005. ...LAKE EFFECT SNOW ADVISORY TONIGHT MIZ006. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1022 PM EST THU DEC 27 2001 01Z SURFACE ANALYSIS SHOWS SURFACE LOW AROUND ANJ WITH SEVERAL TROUGH AXES ROTATING AROUND IT. ONE TROUGH EXTENDS ALONG THE NORTH SHORE OF THE UPPER PENINSULA...A SECOND ONE EXTENDS SOUTH ALONG THE NORTHERN LOWER LAKE MICHIGAN SHORELINE..WITH WEST/NORTHWEST WINDS ALONG THE SHORE AND SOUTHWEST WINDS INLAND. SURFACE LOW HAS SLOWLY RETROGRADED OVER THE PAST SEVERAL HOURS...AND IR LOOPS/SURFACE OB TRENDS WOULD SUGGEST A SECOND CENTER IS FORMING OVER SOUTHEAST LAKE SUPERIOR. KAPX 88D SHOWING A CONTINUATION OF MULTIPLE WESTERLY FLOW BANDS. HAVEN'T REALLY SEEN A DOMINANT BAND SET UP YET...THOUGH PERSISTENT CONVERGENCE MENTIONED EARLIER BEGINNING TO CONCENTRATE HIGHER REFLECTIVITIES BETWEEN M-32 AND M-68 WEST OF I-75. RADAR TRENDS ALSO SUGGEST WEAKER BANDS ON EITHER SIDE OF THIS AREA OF SNOW ARE FALLING APART...ALSO A SIGN THAT STRONGER CIRCULATION DEVELOPING WITH THIS BAND TO THE DETRIMENT OF EVERYTHING AROUND IT. SNOW SHOWERS HAVE ALSO BEEN FAIRLY WIDESPREAD ACROSS EASTERN UPPER THIS EVENING ALONG SURFACE TROUGH AND AIDED BY APPROACHING DYNAMICS. APX 00Z RAOB PEGGED 850MB TEMPERATURES AROUND -13C WITH AN INVERSION AROUND 6500 FEET...GRB 850MB A LITTLE COLDER AT -15C BUT SOUNDING WAS MUCH DRIER ABOVE INVERSION. MAIN CONCERNS TONIGHT OBVIOUSLY CENTER AROUND CONTINUED LAKE EFFECT/ENHANCED SNOW SHOWERS. EASTERN UPPER...COMPLICATING FACTOR HERE IS POSITION OF SURFACE LOW... WHICH IS LIKELY TO MOVE LITTLE FOR MUCH OF THE NIGHT AND THUS KEEPING SURFACE FLOW ON THE LIGHT SIDE. WINDS IN THE LOW LEVELS FORECAST TO REMAIN GENERALLY WESTERLY OVER LAKE SUPERIOR AND BECOMING MORE NORTHWESTERLY OVER LAKE MICHIGAN. RUC INSISTING ON MORE OF A SOUTHWEST FLOW EARLY ON...BUT KAPX/KMQT VWP'S AND RADAR TRENDS SUGGEST WINDS WILL PROBABLY HAVE MORE OF A NORTHERLY COMPONENT OVERNIGHT...HOWEVER SLIGHT. THIS WILL LIMIT CONVECTIVE ELEMENTS FROM AFFECTING THE BULK OF THE AREA OVERNIGHT...THOUGH ENHANCED MID LEVEL MOISTURE COMBINED WITH LOW LEVEL CONVERGENCE AND SOME UPPER SUPPORT WILL CONTINUE TO PRODUCE SNOW SHOWERS OVERNIGHT. WILL WORD ENTIRE AREA FOR 1-2 INCHES...AND REMOVE THREAT FOR HIGHER TOTALS ALONG THE SOUTH SHORE FOR NOW. NORTHERN LOWER...WV IMAGERY SHOWS UVV FIELD ASSOCIATED WITH SHORT WAVE DROPPING SOUTHEAST OUT OF MN NOW SPREADING ACROSS WI. UPSTREAM 00Z RAOBS (GRB/DVN) WERE DRY ABOVE 700MB...WITH BETTER MOISTURE FARTHER UPSTREAM ACROSS MN. QUITE A BIT OF SNOW SHOWER ACTIVITY HAS BEEN PULLING ACROSS THE LAKE THIS EVENING...THOUGH TO NO GREAT EFFECT ACROSS AREAS SOUTH OF M-72 WITH LITTLE MORE THAN FLURRIES THUS FAR AT MBL/ LDM...LITTLE BETTER SNOWFALL FARTHER INLAND AT CAD/HTL. INITIAL FORCING FROM SHORT WAVE WILL PULL INVERSION HEIGHTS UP ABOVE 8K FEET OVERNIGHT OVER NORTHERN LAKE MICHIGAN...WHICH IN ITSELF WILL HELP INCREASE SNOWFALL INTENSITY...WITH SOME ENHANCEMENT FROM BETTER MID LEVEL MOISTURE ARRIVING LATER. CURRENT WARNING WILL REMAIN INTACT AND GIVEN CURRENT RADAR TRENDS WILL TRY TO REFINE WORDING OF HEAVIEST ACCUMULATIONS OVERNIGHT INTO AREAS SOUTH OF M-68/NORTH OF M-32...WITH LIGHTER ACCUMULATIONS AROUND THAT AREA. WILL DROP ADVISORY FOR BENZIE/GRAND TRAVERSE/KALKASKA GROUPS AND LOWER ACCUMULATIONS A BIT SINCE LITTLE HAS OCCURRED SO FAR THIS EVENING. UPDATED ARBZFPAPX WILL BE OUT BY 0345Z. .APX...LAKE EFFECT SNOW WARNING...OVERNIGHT THROUGH FRIDAY... JPB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1100 AM EST THU DEC 27 2001 SURFACE LOW POSITIONED JUST NE OF THE SAULT CONTINUES TO CIRCULATE COLD AIR ACROSS THE GREAT LAKES...THUS CONTINUING THE LAKE EFFECT SNOW MACHINE. MORNING APX SOUNDING WAS WEAKLY CAPPED...WITH DEEP MOISTURE EXTENDING UP THROUGH ABOUT 600 MB. SUFFICE IT TO SAY... DEPTH OF MOISTURE/CONVECTION ALONG WITH 850 MB TEMPERATURES OF -14/-15C ARE PROVIDING AN EXCELLENT ENVIRONMENT FOR HEAVY SNOW PRODUCTION. THE MAIN AFTERNOON QUESTION IS WHERE THE HEAVIEST SNOW WILL OCCUR. OVERNIGHT...10 TO 15 INCHES OF NEW SNOW FELL ACROSS PARTS OF EMMET AND CHARLEVOIX COUNTIES (BRINGING 36 HR TOTALS UP TO 2-3 FEET). HOWEVER...RADAR AND SURFACE OBSERVATIONS SHOW THE PASSAGE OF A WEAK SURFACE BOUNDARY PAST 2-4 HOURS...WHICH HAS CAUSED WEST-SOUTHWEST SURFACE WINDS TO BECOME MORE WEST-NORTHWEST (A WIND SHIFT OF ONLY ABOUT 20 DEG). THIS HAS CAUSED THE HEAVIEST BANDS TO SHIFT SOUTHWARD A BIT. SO THE RELENTLESS SNOWS ACROSS CHARLEVOIX...EMMET...AND CHEBOYGAN COUNTIES HAVE SLACKENED FOR THE TIME BEING...WHILE THE SNOW ACROSS ANTRIM/LEELANAU COUNTY HAS INCREASED. THE RUC AND MESO-ETA BOTH SHOW ENHANCED LAKE TROUGHING RE-DEVELOPING THIS AFTERNOON AND EVENING...CAUSING WINDS TO TURN BACK TO THE WSW ONCE AGAIN. AS A RESULT...AM INCLINED TO KEEP CURRENT WARNINGS AND ADVISORIES BASICALLY UNCHANGED. THE EXCEPTION WILL BE ACROSS LEELANAU AND ANTRIM COUNTIES...WHERE OVERNIGHT SNOWFALL OF 6-7 INCHES...TOGETHER WITH TODAY/S ACCUMULATIONS WILL PRODUCE 24 HR SNOWFALLS EXCEEDING 8 INCHES. WILL THEREFORE HOIST WARNINGS FOR THESE TWO COUNTIES. IN CHEBOYGAN COUNTY...WHERE SNOWS HAVE DECREASED SIGNIFICANTLY...EXPECT THE SNOW TO INCREASE AGAIN AFTER ABOUT 20Z. .APX...LAKE EFFECT SNOW WARNING...THIS AFTERNOON AND TONIGHT... LAKE EFFECT SNOW WARNING...THIS AFTERNOON...MIZ020-021. WINTER WEATHER ADVISORY....THIS AFTERNOON AND TONIGHT... SMITH mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 300 AM CST THU DEC 27 2001 FORECAST CONCERN IS CLOUD COVER TODAY AND CHANCE OF MORE LIGHT SNOW OR FLURRIES...THEN HOW FAST TO BRING IN ARCTIC PUSH TONIGHT. CURRENTLY..LOTS OF BREAKS OVER SOUTH BUT LOWER CLOUDS ARE PUSHING SLOWLY SOUTH FROM CENTRAL MN. ETA SEEMED TO WANT TO KEEP EXTENSIVE HIGHER..LOW LEVEL RH MORE OUT IN EASTERN DAKOTAS. LOOKING UP TO FAR NORTH..ANOTHER WEAK VORT IS SLIDING SE TOWARD EAST CENTRAL MN. 06Z RUC AND ETA SEEMS TO HAVE BETTER HANDLE THAN 00Z RUNS. LOOKS LIKE BEST CHANCE THOUGH..OVER EAST CENTRAL ON INTO WI. WILL KEEP FLURRIES OVER REST OF EAST. ETA HAS SLOWED THE ARCTIC A BIT THE LAST COUPLE RUNS AND LIKE THE AVN INITIALIZATION OF 850 TEMPS BETTER. FWC MOS GUIDANCE NOT BAD THOUGH...BUT CLOSER TO AVN IN SOUTH. WILL MENTION SOME FLURRIES WITH FRONT AND THEN SOMEWHAT BETTER CHANCE OF LIGHT SNOW LATER FRIDAY AS MID LEVEL TROUGH ROTATES AROUND. PROBABLY STEADY TEMPS OVER MOST AREAS ON FRIDAY BUT MAYBE FALLING SOUTH..DEPENDING ON LOWS OVERNIGHT. MRF 6-10 DAY 500 HEIGHTS STILL SHOWING SOME PACIFIC FLOW BREAKING THROUGH MID NEXT WEEK AT OUR LATITUDE..BUT NEW UPPER LOW WITH ARCTIC REBUILDING OVER FAR N CANADA. .MSP...NONE. RICHARDSON mn FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 845 PM CST THU DEC 27 2001 FORECAST CHALLENGE CONCERNS CONTINUED -SN AND TEMPS. KMVX-88D SHOWING BANDS OF -SN CONTINUING ACROSS CENTRAL/SOUTHERN RED RIVER VALLEY ALONG NARROW NW-SE ORIENTED 850MB BAROCLINIC ZONE DEPICTED BY RUC ANALYSIS. ABOVE ALSO AIDED BY WK IMPULSES ROTATING AROUND UPPER LOW NORTH OF GREAT LAKES FROM WATER VAPOR LOOP. BASED ON ACCUMULTATION TRENDS FROM TODAY WILL BUMP FLURRY MENTION TO OCNL -SN OVER PORTIONS OF VALLEY AREA FOR AN INCH OR SO OF ADDNL ACCUMULATION. OTWS COLD FRONT ORIENTED ALONG INL BORDER AND WILL CONTINUE TO DROP SOUTH OVERNIGHT. LATEST RUC SHOWING STRONGEST 850MB COLD AIR ADVECTION WILL DROP SOUTH THROUGH WESTERN AND CENTRAL DAKOTAS AND WITH SOLID CLOUD COVER TEMP DROP SHOULD BE GRADUAL. WILL TAKE A LAST LOOK AT CURRENT AND UPSTREAM READINGS BEFORE UPDATE HOWEVER NO BIG CHANGES PLANNED ATTM. .FGF...NONE. VOELKER nd AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN NATIONAL WEATHER SERVICE ABERDEEN SD 830 PM CST THU DEC 27 2001 WESTERN EDGE OF LOW CLOUDS EXTENDS FROM AROUND BIS SE TO ABR AND FSD. THESE CLOUDS HAVE BEEN SLOWLY MOVING ESE THROUGH THE EARLY EVENING...BUT THIS MOTION IS NOW ENDING AS NEXT SHORT WAVE IS NOW ROTATING SOUTH THROUGH SASK. LOW LEVEL MOISTURE IS INCREASING AHEAD OF THIS SHORT WAVE ASSOCIATED WITH A SFC TROF SLIDING INTO NRN NODAK ATTM. THIS INCREASING LOW LVL MSTR/CLOUDS SHOULD CONTINUE TO DROP SOUTH AND MOVE INTO NRN PORTIONS OF SODAK BY LATE EVENING THEN OVER SPREAD THE REMAINDER OF THE REGION LATE TONIGHT. SOME LIGHT SNOW SHOWING UP IN SRN CANADA. WHILE LATEST RUC NOT DEPICTING ANY SIG PCPN WITH THIS SYSTEM...IT DOES INDICATE THE INCREASE IN MSTR/CLOUDS BY LATE TONIGHT ACROSS THE NRN CWA. SHOULD SEE AN INCREASE IN WINDS AS WELL WITH THIS SYSTEM. WILL NEED TO UPDATE CURRENT FORECASTS TO PUSH CLOUD/SNOW TIMING A BIT FAR WEST. WITH CLOUDS REMAINING IN PLACE MOST AREAS EAST WILL NEED TO UP OVERNIGHT LOW FORECASTS JUST A BIT. .ABR...NONE FAUCETTE sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 800 PM EST THU DEC 27 2001 TIMING OF THE NEXT BATCH OF LOW/MID CLOUDS SHOULD BE GENERALLY AFTER MIDNIGHT...PER SATELLITE LOOPS...LATEST RUC MODEL AND LAMP MOS. THESE CLOUDS LOOK TO MAINLY ADVECT INTO THE NRN 2/3RDS OF THE FORECAST AREA...AND GIVEN PAST HISTORY WHILE UNDER THIS W-NW FLOW ALOFT...THE NO MENTION OF FLURRIES SEEMS WISE. LOOKING TO OUR SW...A SRN STREAM SHORT WAVE LOOKS TO SPREAD MAINLY MID/HI CLOUDS INTO SE TN/SW NC...ALSO AFTER MIDNIGHT. A LIGHT SW SURFACE WIND NOTED...WITH WEAK TROUGHS AT THE SURFACE... TWO UPSTREAM AND ONE TO THE LEE OF THE APPALACHIANS. DEWPOINTS AND 00Z TEMPS RUNNING A BIT HIGHER THIS EVENING...AND WITH THE INCREASE IN CLOUDS...MIN TEMP FORECAST IS LIKELY ON TRACK. I MAY SEPARATE THE NE PLATEAU COUNTIES...AS A CHECK OF PLATEAU COOP SITES VERSUSES TYS/OQT FOR THIS WEEK SHOWS MINS THERE HAVE BEEN AVERAGING 3-6 DEGS FARENHEIT LOWER. I MAY BE OPTIMISTIC...BUT THERE COULD BE SOME FAIR AMOUNTS OF SUNSHINE ACROSS THE FORECAST AREA BY EARLY FRIDAY AFTERNOON...WHICH SHOULD HELP US WARM TO SOME NOT AS CHILLY MAX TEMPS. ANYWAY...THE UPDATED ZONES WILL BE ISSUED AROUND 930 PM EST. .MRX... NC...NONE. TN...NONE. VA...NONE. TG tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD, VA 1000 AM EST THU DEC 27 2001 VORT MAX WL MOV ACRS THE AREA LATE THIS AFTN AND EVENG. VORT IS ACCOMPANIED BY SOME MID CLDS. LOOKING AT 06Z ETA AND CURRENT RUC THIS MID CLD THINS AS IT MOVES E AND MAY ONLY CAUSE A BRIEF PERIOD OF BKN ACRS THE NRN CWA. WL HOLD ON TO A MSTLY SUNNY FCST. CURRENT TEMPS FCST LOOKS GOOD. NO UPDATE PLANNED AT THIS TIME. DROPPING SCA AS WINDS SHD STAY UNDER THRU THE AFTN WITH A JUST A FEW GUSTS APPROACHING. SEAS WL REMAIN UNDER CRITERIA WITH W WINDS. FCSTID = 92 SBY 41 26 45 26 / 10 10 10 10 OXB 42 29 44 29 / 10 10 10 10 ECG 45 32 50 32 / 10 10 10 10 ORF 45 32 50 32 / 10 10 10 10 PHF 43 30 46 30 / 10 10 10 10 AKQ 42 27 46 27 / 10 10 10 10 RIC 41 26 45 26 / 10 10 10 10 FVX 42 27 46 27 / 10 10 10 10 .AKQ... MD...NONE. NC...NONE. VA...NONE. 92 va SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO COLORADO 252 AM MST FRI DEC 28 2001 MAIN CHALLENGE TDA WILL BE THE WINDS AND MAX TEMPS...ESPECIALLY ALONG I-25 AND SERN CO. COLD FRONT ANTICIPATED TO MOVE INTO ERN CO LATER TNGT-SAT. STILL SOME UNCERTAINTY ON THE SENSIBLE WX ACROSS SERN CO SAT NGT-SUN. CURRENT: SYNOPTICALLY...FLOW PATTERN IS FAIRLY CHAOTIC WITH MOD- STRONG SHORTWAVE TROUGHS ROTATING OUT OF CAN INTO THE MID SECTION OF THE US AND PACIFIC NW SHORTWAVES WEAKENING AS THEY ADVANCE TOWARDS THE ROCKIES. MAINLY CI/CS CLOUD SHIELD MIGRATING OUT OF WRN US IN ADVANCE OF THE NEXT ULJ. APPEARS MOUNTAIN WAVE CLOUD STARTING TO DEVELOP ALONG ERN CO MTNS AS RUC 500MB WINDS BACKING TO W-NWLY FLOW. ANY SIGNIFICANT WINDS HAVE REMAINED AT HIGHER ELEVATIONS(AOA 8.0K FT MSL) PER METARS/RAWS DATA. LA VETA/MONARCH PEAK(APPROX. 12K FT MSL) DOT AWOS SENSORS HAVE BEEN BLOWING ALL NIGHT(30-40KT G45- 52KT). 08Z FRONTAL BOUNDARY EXTENDED FROM THE FRONT RANGE OF THE NRN ROCKIES INTO NE AND THROUGH THE UPPER MIDWEST. TDA: WINDS AND DEG OF WARM UP THE BIGGEST CHALLENGE TDA. 80-100KT ULJ STILL PROGGED TO RACE ACROSS THE NERN 1/2 OF CO LATER THIS AFTN. KIND OF A NW FLOW CHINOOK PATTERN TDA. MOUNTAIN TOP STABLE LAYER ISN'T ALL THAT GREAT AND NO SIGNIFICANT DOWNWARD FORCING COMING THROUGH TO SPILL HIGHER WIND GUSTS DOWN TO LOWER ELEVATIONS. ALSO... AFT 18Z ETA/MESO-ETA STILL PROJECTING AN INVERTED SFC TROUGH DEVELOPING IN ERN CO. WINDY CONDITIONS SHOULD BE PREVALENT IN THE MOUNTAINS...EXCEPT MAYBE SWRN CO MTNS. SFC WINDS COULD BE ALL OVER THE PLACE ALONG THE I-25 CORRIDOR WITH THE BEST POTENTIAL FOR WINDY CONDITIONS BETWEEN 15Z-21Z. THEN MTN-PLAINS CIRCULATION COULD BE MORE DOMINATE. TOUGH CALL. IF THE WINDS PICK UP TDA... TEMPS COULD REACH INTO THE 50S AOB 6.0K FT MSL PER DRY ADIABATIC LAPSE RATE TO 700MB. ANY POTENTIAL PRECIP WOULD BE ALONG AND W OF CONTDVD...BUT MAY NOT GET INTO SWRN/CNTRL MTNS UNTIL LATE THIS AFTN. CURRENT FORECAST LOOKS IN GOOD SHAPE AND EXPECTING LITTLE CHANGES. TNGT-SAT: PRETTY MUCH FOLLOWED ETA/MESO-ETA FOR BETTER TERRAIN RESOLUTION. AS 80-100KT ULJ EXITS ERN CO...SFC FLOW EXPECTED TO SHIFT N-NELY WITH FRONT RACING TOWARDS ERN SLOPES OF SERN CO MTNS. FRONT IS VERY SHALLOW(ONLY UP TO 6.0K FT MSL)...THOUGH. SFC WINDS SHOULD DIE DOWN ALONG/E OF I-25 AFT 06Z. AS PBL COOLS...MESO-ETA SUGGESTING LOW CLOUDS SHOULD FORM ALONG THE SERN CO MTNS ERN SLOPES AND SERN CO PLAINS. ONLY POTENTIAL LIFT MIGHT BE SOME WEAK OROGRAPHIC ASCENT AND THAT WOULD PROBABLY ONLY BE AROUND THE PALMER DIVIDE. THERE ARE MODEL RUN-TO-RUN CONSISTENCY...BUT INCONSISTENCY BETWEEN MODELS. AVN STILL PRINTING OUT LIGHT QPF ACROSS ERN CO...BUT NOT AS WIDESPREAD IN SERN CO AS PREVIOUS RUNS. 00Z/28 ETA AND 06Z/28 MESO-ETA ARE CONSISTENT WITH NOT REALLY PRINTING OUT ANY QPF IN SERN CO TNGT-SAT. A LITTLE BETTER POTENTIAL FOR PRECIP/QPF WILL BE ALONG/W OF CONTDVD...ESPECIALLY CNTRL MTNS. ERN SAN JUAN/LA GARITA MTNS WILL BE FAIRLY SHELTERED FROM THE WLY OROGRAPHIC MOIST IN-FLOW. ON SAT...LOWER TROP WINDS ARE FAIRLY LIGHT AND ANY ST CLOUDS MAY TEND TO BREAK UP WITH THE LOSE OF LOW LEVEL FORCING AND OROGRAPHIC ASCENT...EXCEPT FOR PERHAPS THE SRN PORTION OF PALMER DIVIDE. WITH THE LACK OF MIXING AND MODIFIED CP AIR MASS ENTRENCHED IN THE LOWER AR RIVER VALLEY. MESO-ETA HAS A WLY FLOW "DRY" POCKET AROUND 750MB- 700MB...WHILE AVN APPEARS TO BE OVERLY MOIST...THIS IS DUE TO VERTICAL RESOLUTION DIFFERENCES. BIGGEST SENSIBLE WX WILL BE COOLER TEMPS. MESO-ETA HAS HIGHS ONLY IN THE 30S AOB 7.0K FT MSL. MAV GUIDANCE MAY BE A LITTLE TOO WARM. COULD BE A SCENARIO WHERE THE SAN LUIS VALLEY IS WARMER THAN SERN CO PLAINS DUE TO LACK OF FRONTAL PENETRATION. CURRENT FORECAST LOOKS TO BE IN THE CORRECT DIRECTION. PLAN TO TWEAK SOME CLOUD WORDING AND BUMP UP PRECIP CHANCES IN CNTRL MTNS(58/59). SAT NGT-SUN: STILL MUCH UNCERTAINTY ON THE ACTUALLY SENSIBLE WX DURING THESE FORECAST PERIODS. ANY BREAKS IN THE SERN CO MTNS/ PLAINS SHOULD FILL BACK IN AS PBL COOLS. AGAIN...THERE ARE MODEL RUN-TO-RUN CONSISTENCY...BUT INCONSISTENCY BETWEEN MODELS. AVN IS CONSISTENTLY MOISTER WITH WIDESPREAD QPF DUE TO STRONGER SHORTWAVE TROUGHS AND ASSOCIATED KINEMATICS. 00Z ETA-ETAX HAVE BEEN CONSISTENTLY STINGY WITH THE QPF FOR THE SERN CO MTNS/PLAINS SAT NGT- SUN. THIS MAKES SENSE HAS IT IS WEAKER WITH THE SHORTWAVES MOVING THROUGH THE W-NWLY FLOW. AVN HAS A SERIES OF WLY FLOW SHORTWAVES MOVING THROUGH THE CNTRL ROCKIES AND IF THIS OCCURS THEN I COULD BUY THE TIGHTER BAROCLINIC ZONE OVER CWA WITH WIDESPREAD QPF BEING GENERATED. SO...IF YOU BUY THE AVN WHOLESALE...THEN POPS COULD BE CATEGORICAL CWA-WIDE. HOWEVER...IF YOU BUY THE WEAKER ETAX SOLUTION...THEN POPS WOULD BE PRETTY LOW OR NIL FOR SERN CO MTNS/PLAINS. 06Z/28 MESO-ETA RUN PRINTING OUT SOME LIGHT QPF SERN CO MTNS AND SRN PORTION OF PALMER DIVIDE LATER SAT NGT. TOUGH CALL IN TRULY SAYING WHICH MODEL IS CORRECT. ONE WOULD THINK THE ETA WOULD HAVE A BETTER HANDLE ON IT WITH HIGHER TERRAIN RESOLUTION...IMPROVED VERTICAL RESOLUTION...AND IMPROVED MODEL QPF AND CLOUD PHYSICS. SINCE THIS IS DAY 3 FORECAST AND THERE WILL BE 4 MODEL RUNS BEFORE THE POTENTIAL EVENT EVEN STARTS SAT NGT-SUN...WILL NOT BE TOO AGGRESSIVE WITH CHANGING THE FORECAST AND REMAIN CONSERVATIVE. PLAN TO INTRODUCE SOME LOW POPS AROUND SERN CO MTNS AND I-25 CORRIDOR AND MENTION MENTION "LIGHT SNOW" FOR EXTRA GUIDANCE. LATER FORECASTERS CAN RE-ANALYZE MODEL DATA AS THE EVENT GETS CLOSER. MON-THU: AVN/MRF STILL PRINTING OUT NEARLY WIDESPREAD QPF UNTIL FURTHER NOTICE. OTHER MEDIUM RANGE MODELS SUGGESTING POTENTIAL UNSETTLED WX PATTERN...BUT NOT READY TO BIT AND FLIP-FLOP THE DAY 4-7 FORECAST. WOULD BE NICE TO GET SOME OF THAT MRF QPF ONCE IN A WHILE DOWN HERE IN THE SEMIAIRID DESERT. .PUB...NONE. METZE co NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 940 PM MST THU DEC 27 2001...UPDATE... SHORT TERM DISCUSSION: CONCERN TNT OVER HIGH WIND POTENTIAL FOR THE FRONT RANGE FOOTHILLS FOR LATER TNT/FRI MORNING. STRONG MTN TOP INVERSION HAS DEVELOPED THIS EVENING WITH 100KT JET OVER AREA. AS THIS JET SLIPS EAST OF CWA LATER TNT THE SHEAR PROFILE BECOMES MORE FAVORABLE FOR AN AMPLIFIED MOUNTAIN WAVE. ALREADY SOME GUSTS UP AROUND 50 MPH AT RED FEATHER LAKES AND A FEW OTHER RAWS STATIONS. X-SECTIONS FROM RUC/MESOETA SHOWING COMP ALONG INCREASING BTWN 40-50KT AT 07Z-12Z THEN SLOWLY DECREASING BY NOON. THE MM5 MODEL IS EVEN STRONGER WITH SPEEDS OF 80-90KT ABV 8K FEET. THIS IS OBVIOUSLY A LITTLE MUCH...BUT BASED ON 04Z OBS IT MAY NOT BE TOO OVERDONE. LOOKS LIKE INVERSION WILL STAY HIGH ENOUGH AS NOT TO GET HI WINDS OVER ZNS 38..39...BUT STILL BEARS WATCHING LATER TNT. ROCKY FLATS IS GUSTING IN THE 35-45 MPH THIS EVENING WHICH IS TROUBLING. ENTREKIN LONG TERM DISCUSSION: STG NWLY FLOW ALOFT WILL BE OVER THE CWA FRIDAY NIGHT WITH 90+ KT JET IN THE VICINITY. MDLS CROSS-SECTIONS STILL HINT AT SOME WEAK CSI POTENTIAL FRIDAY NIGHT. SNOW AMOUNTS NOT AS OPTIMISTIC AS PRVS MDL RUNS SUGGESTED. SINCE MY CONFIDENCE LEVEL IS RATHER LOW IN TERMS OF THE EXACT LOCATION AND INTENSITY OF THE CSI...I WILL BACK OFF ANY MNTN OF ACCUMULATIONS FOR THE NORTHEAST PLAINS AT THIS TIME. THE NEXT SHIFT SHOULD BE ABLE TO BETTER ASSESS THIS POTENTIAL. ALTHOUGH THE SURGE OF COOLER AIR IN ASSOCIATION WITH NRN PLAINS SFC HIGH WILL PUSH INTO THE URBAN CORRIDOR...ANY UPSLOPE IS PROGGED TO BE WEAK AND VERY SHALLOW SO SCT POPS FOR THE URBAN CORRIDOR LOOK OKAY FOR NOW. AS FOR THE MTNS...BEST SNOW POTENTIAL WILL OCCUR FRIDAY NIGHT WITH H7 WINDS AROUND 35 KTS... MOISTURE DEPTH HOWEVER DECREASES ON SATURDAY SO WILL BACK OFF TO SCT POPS AT THAT TIME. OROGRAPHIC SNOW MDL YIELDED SNOWFALL IN THE 1-4 INCH RANGE FRIDAY NIGHT. FOR SATURDAY NIGHT AND SUNDAY...ENOUGH WIND AND MOISTURE IN THE MOUNTAINS TO KEEP MENTION OF SCT SHSN. FOR THE NORTHEAST PLAINS...AVN INDICATES PLENTY OF RH THERE BUT NOT MUCH AVAILABLE TO LIFT IT UNTIL SUNDAY AFTN...AHEAD OF AN APPROACHING CANADIEN SHORT WAVE. WL UP POPS AGAIN AT THAT TIME. NORTHERLY FLOW ALF WILL CONTINUE OVER THE CWA MONDAY AS ANOTHER SHORT WAVE MOVES INTO THE NRN PLAINS LATE SUNDAY INTO MONDAY. COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL PUSH INTO THE CWA MONDAY MORNING. WILL KEEP A CHC OF SHSN FOR THE NE PLAINS ON MONDAY WITH COOLER TEMPERATURES LINGERING INTO TUESDAY. BEST WARMUP SHUD OCCUR TOWARDS MIDWEEK AS LARGE H5 RIDGE OVER THE WEST DEAMPLIFIES ...THE SFC HIGH OVER THE CENTRAL PLAINS SHIFTS EAST...AND THE FLOW ALOFT BECOMES MORE WLY. MRF MAINTAINS SOME RH AND QPF IN THE MOUNTAINS THROUGH THE MOST OF THE PERIOD WITH MDT NW-WLY FLOW ALF. WL MNTN AT LEAST A SLGT CHC OF -SHSN IN THE MTNS THROUGH THE PD. COOPER .DEN...HIGH WIND WARNING TNT/FRI MORNING...ZNS 35..36. co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 405 AM EST FRI DEC 28 2001 SFC LOW IS NOW CENTERED OVER ERN LAKE SUPERIOR...WITH SHARP LAKE ENHANCED TROUGHING EXTENDING BACK OVER UPR MI...NRN WI AND WRN LWR MI. LATEST IR SATELLITE IMAGE CLEARLY SHOWS A WELL ORGANIZED SHORT WAVE MOVING THRU CENTRAL WI ATTM...WITH SEVERAL SFC OBS REPORTING LIGHT SN OVER NRN WI AND MN AS A RESULT. CLOSER TO HOME...LAKE EFFECT SNOW CONTINUES WITH MAINLY WESTERLY FLOW IN CONTROL. DOMINANT BAND HAS FINALLY ORGANIZED...EXTENDING FROM CHARLEVOIX AND LITTLE TRAVERSE BAY/PETOSKEY TO WOLVERINE TO JUST S OF ONAWAY. LAKE EFFECT SNOW...WHEN...WHERE AND HOW MUCH...WILL REMAIN OUR FORECAST FOCUS THRU THE WEEKEND...TAKING INTO ACCOUNT ANY ENHANCEMENT THAT WILL OCCUR FROM PASSAGE OF THE SHORT WAVE. SOME DISCREPANCIES EXIST BETWEEN THE LATEST MODELS...WHICH WILL PLAY A ROLE IN THE SNOWFALL FORECAST OVER THE NEXT 24 TO 36 HOURS. FIRST OF ALL...LATEST RUC HAS THE BEST HANDLE ON THE CURRENT POSITION AND EXPECTED TRACK OF THE SHORT WAVE NOW MOVING THRU WI...BOTH THE ETA AND AVN ARE SLIGHTLY TOO FAST AND TOO FAR NORTH. ALSO...AVN SEEMS TO BE TOO MOIST THRU MUCH OF THE PERIOD...MAINTAINING MID LEVEL MOISTURE EVEN AFTER THE DEPARTURE OF THE SHORT WAVE AND AS NVA IS MOVING THRU THE REGION. TODAY...DELTA T'S REMAIN AROUND -20 C...WITH INVERSIONS AROUND 8-9 KFT AND PLENTY OF LOW LEVEL MOISTURE THROUGHOUT THE DAY. WINDS HAVE ALREADY BEGUN TO SHIFT TO THE NW ACROSS ERN UPR AND FAR NRN LWR MI. BUT LOW LEVEL CONVERGENCE FUELING THE DOMINANT BAND REMAINS STRONG AND SHOWS UP NICELY IN THE LOW LEVEL OBSERVED WINDS. WINDS AT ACB ARE FROM THE S AND WINDS AT GLR AND TVC ARE FROM THE SW. WILL LIKELY TAKE AWHILE FOR THIS DOMINANT BAND TO BE DISRUPTED BY WINDS SHIFTING TO THE NW...SINCE IT SEEMS TO BE CREATING ITS OWN LOW LEVEL WIND FIELD. BUT DO EXPECT CHANGING SYNOPTIC FLOW WILL EVENTUALLY DISRUPT THIS BAND...SHIFTING BANDS TO A MORE NW/SE ORIENTATION. CHARLEVOIX WILL STILL BE TARGETED...BUT BANDS OF HEAVIER SNOW SHOULD ALSO BEGIN TO IMPACT ALL OF ANTRIM AND OTSEGO COUNTY WITH WINDS SHIFTING TO THE W/NW AS THE DAY UNFOLDS. IN THE MEANTIME...HARDEST HIT LOCATIONS WILL NOT CHANGE FOR THE NEXT FEW HOURS...INCLUDING SRN EMMET...SRN CHEBOYGAN AND EMMET COUNTIES. EXPECT THESE AREAS WILL CONTINUE TO SEE AT LEAST AN INCH AN HOUR SNOWFALL THROUGH MID MORNING BEFORE BANDS BEGIN TO SHIFT TO THE SOUTH. WILL MAINTAIN LAKE EFFECT SNOW WARNING FOR ALL COUNTIES ALREADY IN THE WARNING...AND ISSUE WARNING FOR BENZIE AND GRAND TRAVERSE COUNTIES BASED ON RADAR TREND AND OBSERVER REPORTS OF AROUND 6 INCHES OVERNIGHT FOR NW GRAND TRAVERSE COUNTY. FOR THE REST OF THE AREA...DO EXPECT AN INCREASE IN AREAL COVERAGE OF SHSN DUE TO DIURNAL ENHANCEMENT...AS WELL AS SOME SYNOPTICALLY INDUCED ENHANCEMENT AS THE SHORT WAVE PUSHES THRU CENTRAL AND SRN LWR MI. TONIGHT AND SATURDAY...INVERSION HEIGHTS SLIGHTLY DROP TO AROUND 7-8 KFT...BUT DELTA T'S INCREASE TO THE LOWER -20S WITH AMPLE LOW LEVEL MOISTURE REMAINING IN PLACE. WINDS WILL BE SHIFT FROM NW TO N TONIGHT ACROSS ERN UPR MI AND FROM W/NW TO NW ACROSS NRN LWR MI...SO BANDS ORGANIZATION WILL AGAIN BE DISRUPTED. GIVEN THIS SCENARIO... EXPECT HARDEST HIT AREAS WILL BE THOSE TARGETED BY W/NW AND NW WINDS IN NRN LWR MI (I.E. CHARLEVOIX...ANTRIM AND OTSEGO COUNTIES). CHIPPEWA COUNTY WILL RECEIVE SOME SNOW...BUT AS WINDS SHIFT TO THE N...THEY WILL BE LARGELY OUT OF THE HEAVY SNOW BANDING. WILL NOT ISSUE SECOND PERIOD WARNING AT THIS TIME DUE TO SOME UNCERTAINTY IN EXACTLY HOW/WHEN THE WIND FIELDS WILL SHIFT THROUGHOUT THE NIGHT. BUT DO EXPECT THESE AREAS COULD SEE 3 TO 5 INCHES OF ADDITIONAL SNOWFALL. WINDS SHIFT BACK TO THE NW ON SATURDAY...CONTINUING TO TARGET NW FLOW COUNTIES FOR HEAVIEST SNOWFALL. SATURDAY NIGHT AND SUNDAY...INVERSION HEIGHTS FINALLY BEGIN TO FALL TOWARD 5 KFT AS BUILDING SUBSIDENCE/ANTICYCLONIC FLOW PRODUCES WARMING ALOFT. DELTA T'S (-19 TO -20 C) AND LOW LEVEL MOISTURE (AROUND 70 PCT) REMAIN SUFFICIENT FOR CONTINUATION OF LAKE EFFECT SHSN AS WINDS SHIFT AGAIN TO THE W/NW. WILL MAINTAIN SCT/NMRS SHSN FOR MUCH OF THE CWA...WITH BEST CHANCES OF SNOW REMAINING ACROSS THE LAKE SUPERIOR AND LAKE MICHIGAN SNOWBELT AREAS. FORECAST FOR MONDAY LOOKS IN LINE WITH LATEST MODEL DATA...NO CHANGES AT THIS TIME. THANKS TO MQT FOR COORDINATION. .APX...LAKE EFFECT SNOW WARNING...TODAY... EME mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 200 AM CST FRI DEC 28 2001 PRIMARY FORECAST CONCERNS CENTERED ON TEMPERATURE TRENDS AND WHAT EFFECT CLOUDS WILL HAVE. EARLY MORNING WATER VAPOR AND LAST EVENINGS UPPER AIR ANALYSIS SHOWED UPPER LEVEL LOW SITUATED NORTH OF THE GREAT LAKES...WITH NEXT SHORT WAVE POISED NEAR THE NORTH DAKOTA/MONTANA BORDER. 850MB TEMPERATURE ANALYSIS INDICATED POOL OF MINUS 20C AIR ACROSS ONTARIO/MANITOBA. LIGHT SNOW CONTINUES OVER MUCH OF THE UPPER MIDWEST AS SHOWN BY RADAR AND SURFACE OBSERVATIONS...WITH EXTENSIVE CLOUD COVER NOTED IN 11-3.9 MICRON SATELLITE IMAGERY. 00Z MODELS IN AGREEMENT ON BRINGING THE MINUS 20C TEMPERATURES AT 850MB SOUTHWARD TONIGHT AND SATURDAY. MEANWHILE...PIECES OF SHORT WAVE ENERGY CONTINUE TO ADVANCE THROUGH THE FORECAST AREA...AS THE UPPER LEVEL LOW REMAINS NORTH OF THE GREAT LAKES. NO DOUBT ADDITIONAL ROUNDS OF LIGHT SNOW ANTICIPATED...WITH ONLY MINOR ACCUMULATIONS. BIGGEST QUESTION WILL BE CLOUD COVER EFFECTS ON TEMPERATURES. AS OF 06Z THIS MORNING...THE ETA 2M AND LATEST RUC 2M TEMPERATURES WERE 5F TO 10F DEGREES TOO COLD IN THE FORECAST AREA...AS WELL AS UPSTREAM. THIS LIKELY DUE TO THE CLOUD COVER OVER THE REGION...WHICH TIME/HEIGHT CROSS SECTIONS INDICATED WOULD PROBABLY HANG AROUND. THE ETA AND RUC 2M VALUES APPEAR TO CONTINUE THIS COLD BIAS INTO TODAY...SO WILL PROBABLY NEED TO RAISE FORECAST HIGHS A BIT. TONIGHT AND SATURDAY...COLDEST READINGS OF THE SEASON ANTICIPATED... BUT CLOUD COVER COULD PREVENT TEMPERATURES FROM DROPPING AS COLD AS GUIDANCE SUGGESTS. SINCE ITS THIS MIDNIGHT CREWS FIRST DAY BACK...WE PREFER TO MAINTAIN CONTINUITY WITH CURRENT FORECAST TEMPERATURES...ALLOWING FURTHER EVALUATION OF SUBSEQUENT MODELS AND CLOUD TRENDS. OTHERWISE...FORECAST SCENARIO OF A LOT OF COLD AND A LITTLE SNOW FOR THE LAST WEEKEND OF THE YEAR APPEARS IN GOOD SHAPE. .LSE...NONE. THOMPSON wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 1010 AM EST FRI DEC 28 2001 SATELLITE SHOWS THUNDERSTORM CLOUD TOPS ASSOCIATED WITH THUNDERSTORM COMPLEX ARE CONTINUING TO COOL S OF NEW ORLEANS AHEAD OF THE UPPER SHORTWAVE EXITING THE TX COAST. CLOUDINESS FROM THIS SYSTEM IS CURRENTLY SPREADING E INTO THE CWFA. WILL MENTION INCREASING CLOUDINESS FOR ZONES AND WILL ALSO MAKE A FEW TEMPERATURE ADJUSTMENTS. MARINE: WINDS STAYING LIGHT AT THIS TIME...AND 13Z RUC SUGGESTS WINDS WILL STAY RELATIVELY LIGHT NEAR THE STATIONARY FRONT THAT IS POSITIONED JUST OFF THE NRN GULF COAST. WILL LOWER WINDS AND SEAS SLIGHTLY FOR UPDATES. .TLH... .AL...NONE. .GA...NONE. .FL...NONE. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 330 PM EST FRI DEC 28 2001 ...HEADLINES CONTINUE FOR LAKE EFFECT SNOW ACROSS THE UPPER PENINSULA... .OVERVIEW...AREA OF LES CONT OVER THE N CENT UPPER PENINSULA AND OVER THE WRN ZONES THIS AFTN AS SFC BOUNDARY PUSHING INTO THE AREA. WSETA AND RUC HAVE BEST HANDLE ON WIND FIELDS...HIGHLIGHTING AREAS OF BEST CONVERGENCE WHERE CURRENT RADAR AND SATELLITE DATA SHOWS HEAVIER SNOW BANDS OCCURRING. OTHERWISE...SHORT RANGE MODELS IN RELATIVELY GOOD AGREEMENT THRU 24 HRS WITH AVN DIVERGING WITH PLACEMENT OF ERN CANADIAN VORTEX AFTER THEN. THIS DIFFERENCE FAIRLY MINIMAL AND WL NOT HAVE MUCH OF AN IMPACT ON FORECAST NO MATTER WHICH VERIFIES BETTER AS ONGOING CYCLONIC FLOW ALOFT AND NRLY SFC FLOW ACROSS LK SUPERIOR TO CONT LONG LASTING LES EVENT. MAIN CHALLENGE IS DEFINING AREAS WHERE BEST SNOWFALL TO OCCUR. .SHORT TERM...NORTH WINDS BEHIND SFC BOUNDARY TO KEEP THE SNOW MACHINE GOING OVERNIGHT. TEMP DIFFERENCES BETWEEN LK SUPERIOR AND 850 MB TO INCREASE OVERNIGHT...REACHING AS HIGH AS 22 C...AS COLD POOL SETTLES IN. DECENT FETCH ACROSS THE LK ALSO SUPPORTS ENHANCED LES WITH THE NORTH WINDS...ESPECIALLY IN THE CENTRAL AND ERN SECTIONS OF THE REGION. FURTHER W...VORTICITY LOBE ROTATING AROUND MAIN 5H LOW CURRENTLY MOVING INTO NRN MN AND WL ENHANCE SNOW ACROSS THE WRN UPPER PENINSULA OVERNIGHT. CLOUD TOPS ALREADY COOLING ACROSS WRN LK SUPERIOR IN RESPONSE TO THIS FEATURE THUS THIS AREA WL SEE ADDITIONAL SIGNIFICANT ACCUMULATIONS EARLY TONIGHT. ONLY LOCATION THAT IS QUESTIONABLE IS BARAGA COUNTY WHERE SHADOW OF THE KEWEENAW PENINSULA WL LIMIT LES POTENTIAL THERE BUT ENHANCEMENT FROM AFOREMENTIONED VORTICITY LOBE MAY BRING A BRIEF PD OF HEAVIER SNOWFALL. ATTM WL LEAVE BARAGA COUNTY OUT OF HEADLINES AS PRESENT PATTERN NOT FAVORABLE FOR SIGNIFICANT LES THERE AND DO NOT EXPECT SYNOPTIC FORCING TO LAST LONG ENOUGH TO PRODUCE ADVISORY CRITERIA FOR SNOWFALL. OVER THE FAR E...WINDS TO SHIFT A BIT MORE TO THE NE OVERNIGHT WHICH WL LIMIT LES PRODUCTION. ACROSS THE REMAINDER OF THE UPPER PENINSULA WL INCREASE POPS AND BUMP UP SNOWFALL AMOUNTS SLIGHTLY BUT THESE AREAS TO STAY BLO ADVISORY CRITERIA. AS FOR TEMPS...OVERNIGHT LOWS TO BE SIMILAR OR A BIT COOLER THAN THIS MORNING/S READINGS WITH COLD AIR ADVECTION CONTINUING. .LONG TERM...WINDS BEGIN SHIFTING BACK TO THE NW ACROSS LK SUPERIOR SATURDAY. PAST TIMING OF WIND SHIFTS HAS BEEN A BIT LATER THAN INDICATED BY THE MODELS AND THUS EXPECT DECENT LES TO CONT INTO THE AFTN. WINDS TO BE MORE WRLY BY 6Z SUNDAY WHICH WL DIMINISH SNOWFALL OVER ALL BUT FAR WRN ZONES. BLUSTERY WINDS ACROSS THE NRN TIER OF COUNTIES TO PRODUCE BLOWING AND DRIFTING OF VERY POWDERY SNOW WHICH WL LIMIT VSBYS ACROSS THE REGION...ESPECIALLY IN THOSE FEW OPEN AREAS THAT HAVE RECEIVED SIGNIFICANT SNOWFALL. NO HEADLINES FOR REDUCED VSBYS...HOWEVER CONT LES WARRANTS CONTINUANCE OF WSW ACROSS THE WEST INTO SATURDAY NIGHT. WINDS SHIFT A BIT MORE NW ON SUNDAY... AGAIN FAVORING LES ACROSS THE WRN AND ERN SECTIONS OF THE REGION. HOWEVER TEMP DIFFERENCES BETWEEN THE LK AND 850 MB DIMINISH AS SLIGHTLY WARMER AIR MOVES IN BUT WITH CYCLONIC FLOW PREVAILING AND DECENT CONVERGENCE EXPECTED ALONG LAKE SHORE POTENTIAL EXISTS FOR CONT WSW IN THE FAVORED AREAS INTO SUNDAY. FOR NOW WL ONLY EXTEND WSW THRU SATURDAY NIGHT...AND LET SUBSEQUENT SHIFTS MAKE THE FINAL DETERMINATION AS TO HOW FAR TO EXTEND HEADLINES AFTER THEN. NOT MUCH VARIABILITY IN TEMP FORECASTS EXPECTED AS REGION REMAINS LOCKED IN CURRENT PATTERN THRU SUNDAY. DO EXPECT A SLIGHT RECOVERY ON SUNDAY AS 1000 TO 850 AND 1000 TO 500 MB THICKNESSES RECOVER. MORE VARIABILITY FORECAST ALONG THE SRN ZONES AWAY FROM LK SUPERIOR AND WL PLACE THE BIGGEST DIURNAL RANGES THERE. .EXTENDED...MODELS IN RELATIVELY GOOD AGREEMENT THRU DAY 4 AND THEN DIVERGE WITH RESPECT TO 5H PATTERN. MRF AND CANADIAN CLOSEST TO EACH OTHER AFTER THEN...WITH ONLY A TIMING DIFFERENCE REGARDING SHRTWV MOVING THRU THE UPPER MIDWEST LATE IN THE WEEK. EARLIER ON IN THE EXTENDED...BLOCKING RDG OVER THE NRN ATLANTIC GRADUALLY SHIFTS E WITH TIME ALLOWING 5H LOW OVER ERN ONTARIO TO LIFT NE. THIS FEATURE TO CONT TO BRING WEAK SHRTWVS INTO THE GRT LKS REGION WITH NW FLOW PREVAILING. WHILE LK SUPERIOR VERSES 850 MB TEMP DIFFERENCES DIMINISH SLIGHTLY EARLY ON...STILL HIGH ENOUGH AT 15 TO 18 C...FOR LAKE EFFECT SNOWS TO CONT THRU WED IN THOSE AREAS FAVORED BY W TO NW SFC WINDS. COLD FRONT SWINGS INTO THE REGION THU AS DEEP 5H LOW DROPS IN FROM THE NW. SYNOPTIC SCALE LIFT COMBINED WITH ARCTIC AIR BLASTING IN SUPPORTS SNOW FORECAST FOR THU. LK EFFECT SNOW CRANKS UP AGAIN THU NIGHT AND FRI WITH HIGH DELTA T/S BETWEEN LAKE SFC AND 850 MB TEMPS AND DECENT FETCH ACROSS THE LAKE WITH NRLY WINDS. QUESTION REMAINS ON HEIGHT OF INVERSION AS THIS COLD AIRMASS MAY BE QUITE SHALLOW INITIALLY AS MRF MAY BE A BIT TOO AGRESSIVE WITH DEEP COLD AIR. THANKS FOR COORDINATION APX. .MQT...LAKE EFFECT SNOW WARNING TONIGHT THRU SAT NIGHT MIZ001>003-006-009. LAKE EFFECT SNOW WARNING TONIGHT AND SAT MIZ005. RJT mi PRELIMINARY AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 215 PM CST FRI DEC 28 2001 FORECAST CHALLENGES: PRECIPITATION CHANCES TONIGHT AND AGAIN MONDAY THROUGH WEDNESDAY...AND TEMPERATURES THROUGHOUT. FORECAST AREA ENJOYING A BRIEF WARMUP TODAY...WITH TEMPERATURES IN THE 40S TO LOWER 50S. SCATTERED CLOUD COVER...MOSTLY CIRRUS...MOVING OVERHEAD. WATER VAPOR LOOP/RUC 300-500MB VORTICITY SHOWS NEXT SYSTEM TO AFFECT THE OZARKS OVER THE SOUTH DAKOTA/MINNESOTA BORDER AT 19Z. THE UNDERLYING THEME FOR THIS FORECAST PACKAGE IS THE LACK OF AVAILABLE MOISTURE. AT LEAST THREE SYSTEMS WILL AFFECT THE REGION DURING THE NEXT 7 DAYS...BUT NONE OF THEM WILL HAVE SUFFICIENT MOISTURE TO CAUSE MAJOR PROBLEMS. FIRST WAVE WILL MOVE INTO THE SHOW ME STATE EARLY THIS EVENING...WITH AN AREA OF LIGHT SNOW/FLURRIES EXPECTED TO DEVELOP ALONG AND AHEAD OF IT. SURFACE REFLECTION IS WEAK...WITH LIFT OCCURRING IN MID LEVELS. AVN IS THE MOST BULLISH ON THIS SYSTEM...BUT HAVE SIDED MORE TOWARD THE ETA. RAPID CLEARING TO OCCUR SATURDAY MORNING...WITH SUNNY BUT COOL WEATHER THROUGH SUNDAY. NEXT WAVE ROLLS INTO THE SOUTHERN PLAINS SUNDAY NIGHT...WHICH WILL INCREASE THE CLOUD COVER ACROSS THE FORECAST AREA. HAVE OPTED TO LEAVE PRECIPITATION OUT OF THIS FORECAST FOR NOW...AND ANYTHING THAT DOES OCCUR WILL BE LIGHT. CLOUD COVER WILL HOLD FAST FOR MOST OF THE WEEK...AS REINFORCING SHOTS OF COLD AIR ROTATE INTO THE MISSISSIPPI VALLEY REGION FROM CANADA. MRF SHOWS 850 MB TEMPS FROM -12 TO -14 WEDNESDAY AFTERNOON ...WITH A COLDER AIRMASS EXPECTED FRIDAY (-15 TO -20). HAVE LEANED IN THE DIRECTION OF THE MRF AND LOWERED TEMPERATURES IN THE EXTENDED PERIOD...BUT WILL NOT FOLLOW THE MRF VERBATIM AT THIS TIME. ISC GRIDS HAVE BEEN SENT. .SGF... MO...NONE. KS...NONE. SUTTON mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1142 AM EST FRI DEC 28 2001 STORM SYS TO MOVE DOWN ACRS ONT TODAY...THEN TO THE NORTH OF THE FA TONITE. S/W (AS SEEN IN H2O VAP IMAGERY) TO MOVE ACRS THE GREAT LKS REGION TODAY AND THE FA TONITE. 12Z 40KM RUC SHOWS TEMPS TO GET UP INTO THE LWR TEENS-M20S TODAY WITH S-SW SFC WINDS AT 5-10 KTS. T1MAX TEMPS ARE IN THE U20S-M30S. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON CURRENT OBS TRENDS AND ABOVE DATA. SOME LOW-LVL (AND MID-LVL) MSTR TO MOVE IN ACRS THE FA FROM THE WEST TODAY. PW VALUES LOOK TO BE AOB 0.25" TODAY AND TONITE ACRS THE FA. RUC SHOWS PCPN TO AFFECT MOSTLY NY STATE TODAY. H85 WAA TO TAKE PLACE ACRS THE FA TODAY...THEN CAA TONITE. SOME LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA TODAY. PLENTY OF LOW-LVL MSTR TO BE LOCATED ACRS THE FA TONITE. SOME MID-LVL MSTR TO AFFECT THE FA AS WELL TONITE (ESPECIALLY ACRS THE NRN TIER ZONES). LOW-LVL (AND MID-LVL) LAPSE RATES TO BE HIGH ACRS THE FA TODAY AND TONITE. NGM BUFKIT SHOWS LES BAND OFF LK ONT TO MIGRATE TO THE NORTH OF THE CANADIAN BORDER FOR A TIME TODAY...THEN MOVE DOWN ACRS ST LAW CTY AGAIN BY LATER TODAY AND INTO THIS EVENING. BUFCAN/KTYX RADAR DATA TRENDS THIS MORNING SUPPORT THIS. LES BAND LOOKS LIKE IT/LL SET UP TO THE SOUTH OF THE FA BY LATER TONITE. SPOTTER/COOP REPORTS INDICATE AS MUCH AS 9" OF NEW SNOW HAS FALLEN IN SW ST LAW CTY OVER THE LAST 24 HRS. WILL CONT LES WARNING IN THAT NECK OF THE WOODS THRU TONITE. FEW TWEAKS TO FIRST PERIOD CLD COVER FORECAST BASED ON VIS SAT PIX TRENDS. WILL CONT WITH SCT POPS ACRS MUCH OF NY STATE (OUTSIDE OF LES BAND) TODAY AND PREVIOUS ZFP POPS FOR TONITE. FEW COSMETIC CHANGES TO ZONES FOR PERIODS ONE THRU THREE AND I RE-GROUPED THE NRN ADIRONDACKS ZONES TOGETHER FOR THIS UPDATE PACKAGE. WRK ZONES...FINAL ZFP AND WSW ALREADY ISSUED. LATER... .BTV...LES WARNING THROUGH TONIGHT FOR NYZ026. MURRAY vt