WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 300 AM MST MON JAN 24 2000 DEEP LAYER OF MOISTURE WILL AGAIN MOVE IN OVER CWA DUE TO SOUTHEAST FETCH OF WARM...MOIST AIR. FETCH HAS MORE OF A SOUTHERLY COMPONENT NOW COMPARED TO LATE LAST WEEK...RESULT OF AMPLIFYING TROUGH OVER PACIFIC AND RIDGE OVER WESTERN STATES. EXPERIENCE OF LAST COUPLE WEEKS HAS BEEN THAT SUCH A DEEP LAYER OF MOISTURE ENOUGH TO CREATE AT LEAST SOME SCATTERED RAIN AND SNOW SHOWERS THROUGH LOWER ELEVATIONS...IN SPITE OF WEAK DYNAMICS. AND...OF COURSE...MODELS DISAGREE IN VARIOUS WAYS ON FORECASTED DYNAMICS OVER NEXT COUPLE OF DAYS. HOWEVER...AGAIN USING RECENT EXPERIENCE...ETA HAS TENDED BEST IN SIMILAR PATTERNS. ETA AND RUC BOTH PICKING UP SOME WEAK OMEGA ALONG THE WEST SLOPE THIS MORNING...SO WILL PUSH CHANCES OF PRECIP UP INTO THE SCATTERED CATEGORY...PULLING BACK SLIGHTLY TONIGHT...THEN UP AGAIN LATE TUESDAY AS A BETTER ORGANIZED SYSTEM APPROACHES. FREEZING LEVELS FORECASTED TO BE SLIGHTLY LOWER THAN THOSE LAST WEEK...DOWN TO ABOUT 7000 FEET. TEMPERATURES TO CONTINUE TO RUN SLIGHTLY ABOVE NORMALS. GUIDANCE HAS BEEN IN BALLPARK LAST COUPLE OF DAYS SO WILL STEER CLOSE TO OUTPUT. FOR THE EXTENDED...RECENT RUN OF MRF FAIRLY CLOSE IN SOLUTION TO PREVIOUS RUN. MOST NOTABLE EXCEPTION IN 3 TO 5 DAY TIME PERIOD IS MID-WEEK DISTURBANCE. PREVIOUS RUN HAD MOST IMPACT TO CWA WEDNESDAY NIGHT...LATEST RUN IS ABOUT 12 HOURS FASTER AND MORE OF A TUESDAY NIGHT AND WEDNESDAY TIME FRAME. ECMWF AND UKMET SOLUTIONS FAIRLY CLOSE TO MRF. CURRENT EXTENDED HAS A BROADBRUSH APPROACH TO DEAL WITH CONTINUED SERIES OF SMALL DISTURBANCES. APPEARS ON TRACK SO DON/T SEE ANY REASON TO MAKE MAJOR CHANGES. SURPRISINGLY...AFTER WEDNESDAY THE TWO RUNS FALL BACK IN PHASE WITH A CUTOFF LOW DEVELOPING OVER SOUTHERN AZ FRIDAY. WESTERN COLORADO AND EASTERN UTAH EMERGENCY MANAGERS SHOULD MAINTAIN A NORMAL LEVEL OF WEATHER AWARENESS TODAY. .GJT...NONE. GL co AREA FORECAST DISCUSSION...AMENDMENT NATIONAL WEATHER SERVICE JACKSONVILLE FL 945 AM EST MON JAN 24 2000 ...AMENDED TO INCLUDE SEVERE THUNDERSTORM WATCH... LINE OF TSTMS INCREASING OVER NERN GULF OF MEXICO AND FL PANHANDLE AHEAD OF A STRONG UPPER LEVEL TROUGH. RUC INDICATES INCREASING INSTABILITY AS THE FRONTAL WAVE NR VPS/PAM BEGINS TO DEEPEN AND APPROACH N FL/SE GA. STORMS WILL BE MOVING RAPIDLY FROM THE SOUTHWEST TO NORTHEAST NEAR 40 MPH. WIND GUSTS TO 70 MPH AND LARGE HAIL TO 2 INCHES WILL BE THE PRIMARY THREATS. WATCH INCLUDES ALL OF NORTH FLORIDA EXCEPT FLAGLER COUNTY AND INCLUDES THE FOLLOWING COUNTIES OF EXTREME SERN GA...CAMDEN...CHARLTON...CLINCH...ECHOLS...WARE. WAYCROSS...BRUNSWICK AND ST. SIMONS ISLAND ARE JUST NORTH OF THE ACTUAL WATCH BOX...BUT REMEMBER A WATCH MEANS THAT SEVERE THUNDERSTORMS COULD OCCUR IN AND NEAR THE WATCH BOX...INTERESTS IN THOSE COMMUNITIES SHOULD REMAIN ALERT FOR SEVERE WEATHER. .JAX... GA...SCA ALTAMAHA SOUND-FERNANDINA BEACH. SEVERE THUNDERSTORM WATCH THRU 10 AM EXTREME SERN GA. FL...SEVERE THUNDERSTORM WATCH THRU 10 AM N FL. UPDATED ZONES TO REMOVE THE SEVERE THUNDERSTORM WATCH FROM ECHOLS AND CLINCH COUNTIES IN SOUTHEAST GEORGIA...AND HAMILTON AND SUWANNEE COUNTIES IN NORTHEAST FLORIDA. WILL UPDATE THE REMAINDER OF THE ZONE PACKAGE TO REMOVE WATCH FROM REMAINDER OF THE NORTHEAST FLORIDA ZONES. SCOTT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1100 PM EST MON JAN 24 2000 MAIN FORECAST CONCERN IS DEVELOPING LES EVENT. SFC ANAL SHOWS LOW PRESSURE OVER E ONTARIO WITH TROF/COLD FRONT CROSSING UPR MI THIS EVENING. WV IMAGERY SHOWS SHORTWAVE JUST ENTERING W CENTRAL WI AT 02Z. 00Z RAOBS ALSO DEPICT THE SHORTWAVE JUST WEST OF THE FA. UPSTREAM SOUNDING AT KINL SHOWED INVERSION LEVEL AROUND 840MB (5100FT) WITH RELATIVELY UNIMPRESSIVE BL MOISTURE. CWPL SOUNDING SHOWS INVERSION AROUND 780MB (6900FT)... NEARLY SATURATED FROM 850-770MB AND LOWER RH BELOW 850MB. OTHER UPSTREAM RAOBS ALSO SHOWING LOW MOISTURE ABOVE 850MB. MESOETA DID DECENT JOB INITIALIZING 850MB TEMP FIELD...BETTER THAN RUC...SO WILL FOLLOW IT FOR DETAILS. LATEST 88D IMAGES (~0330Z) SHOWING SOME E-W ORIENTED BANDS OVER E LAKE WITH ISOLATED 28+ DBZ...DRIFTING SOUTHWARD TOWARD MQT/ALGER/SCHOOLCRAFT/LUCE COUNTIES. EXPECT THIS TO DRIFT INLAND OVER NEXT HOUR WITH A BRIEF BURST OF SNOW... WITH BANDS REORGANIZING FROM THE N/NW SHORTLY THEREAFTER. DELTA T/S ARE ALREADY NEAR 20C OVER W LAKE AND WILL APPROACH 20C OVER E LAKE BY 06Z. AREA OF H7-H3 QVEC CONV OVER FA ASSOCIATED WITH SHORTWAVE TO OUR WEST WILL SPEED UP DEVELOPMENT OF -SHSN AND ENHANCE SNOWFALL EARLY. RECENT OBS HAVE SHOWN SOME LIGHT SNOW IN NE MN. LAKE ENHANCED SFC TROF WILL ALSO AID LOW LEVEL CONVERGENCE. GIVEN RELATIVELY EARLY START OF SNOW IN EAST...BUMPED UP ACCUMS SLIGHTLY FOR 1ST PERIOD ALGER/LUCE. ADJUSTED 2ND AND 3RD PERIOD FOR LUCE SINCE N WIND TOMORROW IS UNFAVORABLE FOR LES. ALSO ADDED ACCUMS 2ND PERIOD FOR MQT COUNTY...WHERE 360 WIND TOMORROW WILL BE FAVORABLE FOR ACCUMULATIONS. FACTORS NOT IN FAVOR OF HIGHER ACCUMS IN THIS OVERALL EVENT ARE VERY DRY AIR ABOVE BL... TENDENCY FOR INCREASED ANTICYCLONIC FLOW WITH TIME... AND LACK OF ANY GOOD SYNOPTIC SCALE FORCING AFTER THE OVERNIGHT PERIOD. WINDS VEERING TO 340 WILL ALSO LIMIT FETCH FOR MUCH OF KEWEENAW PENINSULA. .MQT...LAKE EFFECT SNOW WARNING ONTONAGON AND ALGER OVERNIGHT THROUGH TUESDAY EVENING LAKE EFFECT SNOW ADVISORY GOGEBIC...LUCE...AND SCHOOLCRAFT OVERNIGHT AND TUESDAY LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY HOUGHTON AND KEWEENAW OVERNIGHT AND TUESDAY JS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1008 PM EST MON JAN 24 2000 APX 88D SHOWING LAKE ENHANCED SNOW SHOWERS DEVELOPING OVER NORTHERN LAKE MICHIGAN AND WESTERN STRAITS AREA. THESE LAKE SNOW BANDS HAVE DEVELOPED IN AN AREA OF SOUTHWEST FLOW IN ADVANCE OF A FRONTAL SYSTEM NOW OVER EASTERN WISCONSIN. CURRENT SURFACE OBSERVATIONS FROM WISCONSIN AND NORTHERN MICHIGAN SHOW VISIBILITIES GENERALLY AROUND 2 TO 3 MILES IN LIGHT SNOW. THE MAIN CONCERNS OVERNIGHT WILL BE LAKE EFFECT SNOWS WITH THE SOUTHWEST FLOW AHEAD OF THE FRONT AND THEN NORTHWEST FLOW FROM BEHIND THE COLD FRONT EARLY TUESDAY MORNING. THE LATEST RUC AND MESO ETA DATA SUGGESTS THE COLD FRONT WILL MOVE INTO NORTHWEST LOWER MICHIGAN AROUND 06Z AND THEN INTO NORTHEAST LOWER AROUND 10Z OR 12Z. A 500 MB TROF AND VORT MAX WILL MOVE EASTWARD INTO THE WESTERN LAKES OVERNIGHT TO SUPPLY ADDITIONAL SUPPORT. SURFACE THROUGH 950 MB WINDS TURN FROM THE SOUTHWEST (230) THIS EVENING TO THE WEST BY 06Z AND THEN TO THE NORTHWEST BY 09Z. 850 TEMPERATURES WILL BE AROUND -14C OVER NORTHERN LOWER AND -16C OVER EAST UPPER OVERNIGHT WITH 1000/850 AND 850/700 MB MOISTURE TO AROUND 75 PERCENT THROUGH 12Z TUESDAY. THEREFORE EXPECT LAKE EFFECTS TO CONTINUE OVER EAST UPPER AND NORTHWEST LOWER OVERNIGHT...WITH LIMITED SNOW ACCUMULATIONS AS INVERSION HEIGHTS STAY AROUND 4000 FEET AND WINDS TURN FROM THE SOUTHWEST TO NORTHWEST. THE CURRENT FORECAST IS IN LINE BUT WILL INCREASE SNOW CHANCES OVER THE EASTERN STRAITS AND NORTHEAST LOWER OVERNIGHT... WITH GOOD SURFACE AND UPPER LEVEL SUPPORT AND LOW LEVEL MOISTURE MOVING EAST. .APX...NONE. SWR mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1045 AM EST MON JAN 24 2000 WK SFC TROF THRU SRN ADRNDCKS-NRN PA PROVIDING SOME SHSN IN WRN DIST AND WL INCR POPS THOSE AREAS. RUC CONTS DRYING TREND DURG ERY AFTN...WL REPHRASE CLDS TO BE LESS PESSIMISTIC AND CHG WNDS TO WRLY OR TURNING THAT WAY PER TROF PASSAGE. WL ALSO TURN EVNG TO VRBL CLDS ...THEN THKNG OVRNGT. ANY OTHER CHGS MINIMAL. MCKINLEY .ALY...NY ERN/VT EXTRM SRN/MA EXTRM WRN/CT NW...NONE. ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1005 AM EST MON JAN 24 2000 DELICATE BALANCE OF COLD AIR ADVECTING SOUTHWARD FROM CENTRAL NC INTO THE NORTHERN PORTIONS OF CWFA AND WEAK DIURNAL INFLUENCE. ATTM WILL HOLD OFF ON WSW AS BORDERLINE CONDITIONS EXIST MOST OF AFTN. HOWEVER LATEST RUC HAS COLD BOUNDARY LAYER AIR EVOLVING THROUGHOUT THE AFTERNOON AND WILL MENTION POSSIBLE MIX LATE AFTN NORTHERN COUNTIES IN ZONE UPDATE. AREA TEMPS WILL NEED TO BE LOWERED A TAD AS WELL. CWF...FPSN7 ALREADY AT 30 KTS WITH SEAS AT 6 FT. LATEST RUC SKYROCKETING WNDS BY EARLY AFTERNOON TO GALE FORCE SUPPORTED BY TREND IN MSAS MSLP GRADIENT. GALE WARNING ALREADY UP FOR OUR AREA BY WILL DELETE MENTION OF BECOMING GALE TOWARD EVENING. WILL BE LOOKING CLOSER AS MODEL DATA COMES IN IF STORM WARNING FLAGS WILL NEED TO BE RAISED IN THE AFTN PACKAGE. THANKS FOR THE COORD RAH AND CHS. .ILM...GALE WARNING SURF CITY NC TO SOUTH SANTEE RIVER SC. JFP nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 920 PM EST MON JAN 24 2000 SNOWFALL HAS RANGED FROM AROUND 8 INCHES IN THE NORTH PART OF THE FORECAST AREA...4 TO 5 INCHES IN THE CENTRAL PART...AND LESS THAN 1 IN THE SE PART. THE 00Z RUC...SATELLITE AND RADAR TRENDS SUPPORT THE ETA/S FORECAST OF PCPN ENDING IN THE CSRA BY MIDNIGHT...CAE AREA AROUND MIDNIGHT...AND THE E PART DURING THE EARLY MORNING HOURS. EXPECT LITTLE ADDITIONAL ACCUMULATION EXCEPT IN THE NE PART WHERE AN ADDITIONAL ONE OR TWO INCHES COULD OCCUR. PLAN TO KEEP THE CURRENT ACCUMULATION FORECAST AND CONTINUE THE WINTER STORM WARNING TONIGHT. .CAE...WINTER STORM WARNING TONIGHT SCZ015>016-018-020>022-025>028-030 AND GAZ040-063>065. WINTER WEATHER ADVISORY FOR SNOW TONIGHT SCZ029-031-035>038-041 AND GAZ077. RJL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1030 AM EST MON JAN 24 2000 STRONG SFC LOW DEVELOPMENT OVER FL PANHANDLE THIS MORNING COMBINED WITH 850 MB LOW IN VICINITY OF FFC ON UPPER AIR ANALYSIS PRODUCING PRECIP ACROSS SE PORTION AT PRESENT. UPPER VORT SLOWLY WORKING INTO SRN PORTION OF THE FORECAST AREA YIELDING STRONG Q VECTOR CONVERGENCE ACROSS THE PIEDMONT AND MIDLANDS. MOISTURE PULL NORTHWARD ALONG ERN PERIPHERY OF 850 MB LOW CONT TO PUMP PRECIP INTO THE AREA. CALLS TO COUNTIES SHOWING NEARLY 4 INCHES OF SNOW ON GROUND IN PORTIONS OF THE PRESENTLY WARNED AREA...WILL NEED TO UP FORECAST SNOW TOTALS. THICKNESSES AND MODEL SOUNDINGS SUPPORT ALL SNOW FOR THE REMAINDER OF THE EVENT. LATEST RUC AND MESO ETA AGREE WITH EARLY PANELS FROM NGM AND ETA THAT .25 INCH OR BETTER LIQ EQUIV NOW POSSIBLE FROM ABBEVILLE TO CLT METRO...WITH .10 OR BETTER INTO MOST OF THE UPSTATE. WILL UP AMOUNTS TO 4 TO 6 INCHES IN WARNING AND EXTEND SW INTO ABBEVILLE AND GREENWOOD. WILL ISSUE A WINTER WEATHER ADVISORY FOR UP TO 2 INCHES OF SNOW FROM ELBERT AND HART AND UPSTATE SC...MAINLY S OF INTERSTATE 85...INTO CLEVELAND AND GASTON COUNTIES NC. NEW WSW AND ZONES TO FLY AT 11 AM. .GSP...WINTER STORM WARNING TODAY NCZ071-072-082-SCZ009-011>014-019. ...WINTER WEATHER ADVISORY TODAY NCZ068-070-SCZ004>008-010- GAZ028-029. HG sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1000 AM EST MON JAN 24 2000 WE ARE GETTING REPORTS OF HEAVY SNOW ON TOP OF ICE ACROSS LANCASTER COUNTY. SNOW ALSO FALLING ACROSS PORTIONS OF NEWBERRY CNTY. SLEET HAS STARTED OVER CHESTERFIELD. PLAN TO ISSUE WINTER STORM WARNING FOR MY NORTHWESTERN COUNTIES AND ADISORIES NEXT TIER COUNTIES OVER. 12Z RUC HAS 1304 1000-850 MB THICKNESS MOVING SOUTHWARD DURING THE AFTERNOON WITH PLENTY OF MOISTURE. MESOETA NOT AS COLD BUT MSTR STILL THERE. .CAE...WINTER STORM WARNING SCZ015-020-021. WINTER WEATHER ADVISORY FOR SNOW THROUGH AFTERNOON SCZ016-022-025-026-027-028. LM sc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE COLUMBIA SC 738 AM EST MON JAN 24 2000 VORT ENERGY STRETCHING FROM ONTARIO SW INTO MISS VLLY. SFC LOW NR FL PAN...WITH FRONT NE ACRS S GA TO NR THE SC CST. PCPN AREA DEVLPNG OVR CENT GA/ALA...MOVG ENE. MDLS GENERALLY AGREE. THEY MV VORT ENERGY EAST TODAY...WITH MOST PVA REMAINING TO OUR SOUTH. SFC LOW DEVELOPS WHILE MOVG ENE TO OFFSHORE SC CST BY AFTN. THEY PLACE MST PCPN NR FNT/TRACK OF LOW NR CST...BUT FWC/FAN STILL PROVIDE HIGH POPS TODAY FOR CAE/AGS EVEN IF PROGGED AMTS ARE LIGHTER. LTST RUC MOVES PCPN FURTHER N...WHICH MAKES SENSE GIVEN CURRENT PCPN AREA OVR GA/ALA MOVG ENE. PRTL THKNS/850 TEMPS PROGGED TO FALL THROUGHOUT THE DAY. THIS SUGGESTS -RA COULD MIX WITH SNOW OR SLEET BEFORE ENDING...WITH NO SIGNIFICANT ACCUM EXPECTED. DECREASING CLOUDS TON. FAIR AND COOL TUE. NEXT VORT COMES IN TUE NT/WED...WITH DEVELPNG LOW OFFSHORE. N FLW SHOULD LIMIT MOISTURE FOR US...BUT COULDNT RULE OUT SOME SNOW SHOWERS. COLD AIR REINFORCED THRU LATE WEEK. NEXT WEEKEND LOOKS INTERESTING. ...UPDATED FOR THUNDERSTORMS IN THE CSRA...AGS REPORTING THUNDER... PRELIM CCF CAE RB 37/25/45 800 AGS RB 40/25/47 +00 .CAE...NONE. DCM/TTH sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 940 PM EST MON JAN 24 2000 CURRENT SATELLITE LOOP SHOWING CLOUDS STILL LINGERING AROUND THE MOUNTAINS THIS EVENING. LATEST RUC MODEL INDICATES THAT LOW LEVEL MOISTURE WILL REMAIN TRAPPED AGAINST THE MOUNTAINS WITH A NORTHERLY WIND FLOW. THUS...WILL UPDATE MOUNTAIN ZONES AND VICINITY TO ACCOUNT FOR LINGERING CLOUDINESS OVERNIGHT...AND WILL RAISE TEMPS A CATEGORY IN THESE CLOUDY AREAS. OTHERWISE...MOSTLY CLEAR SKIES SHOULD BE THE RULE TONIGHT IN ALL OTHER ZONES. .MRX... NC...NONE. TN...NONE. VA...NONE. DMG tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 930 AM EST MON JAN 24 2000 MAIN FORECAST CONCERN FOR MORNING UPDATE IS TEMPERATURES...AS ARCTIC FRONT ADVANCES TOWARD FORECAST AREA THIS MORNING. THIS COLDER AIR HAS PUSHED THRU MOST OF KY...AS WELL AS NEARLY ALL OF WEST AND MIDDLE TN. TEMPS AND DEWPOINTS FALLING SHARPLY BEHIND FROPA...AND LATEST RUC MODEL PLUS 85H PLOTFILES INDICATE AT LEAST WEAK COLD AIR ADVECTION (CAA) FOR THIS AFTERNOON. LATEST SURFACE OBSERVATIONS AND MODEL SOUNDINGS SHOW LOW LEVEL CLOUDS MAY BE HARD PRESSED TO BREAK UP...ALTHOUGH WOULD NOT RULE OUT A FEW BREAKS OF SUN BY LATE AFTN IN VALLEY LOCATIONS. EVEN WITH BREAKS OF SUN...THE WEAK CAA AND SNOW COVERED GROUNDS WILL HINDER MUCH IF ANY WARMING OF TEMPS. WILL UPDATE BY 1030 AM AND INDICATE STEADY OR SLOW FALLING TEMPS THIS AFTN...ALSO MOSTLY CLOUDY. WILL BUMP UP WINDS A BIT...ALTHOUGH DO NOT EXPECT MUCH GUSTINESS. A FEW FLURRIES OR SPOTTY SNOW SHOWERS NOT OUT OF THE QUESTION...AS LAPSE RATES REMAIN QUITE STEEP...BUT NOTHING SIGNIFICANT ANTICIPATED. .MRX... NC...NONE. TN...NONE. VA...NONE. TG tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 956 AM EST MON JAN 24 2000 WK TROF TO MOVE ACRS THE FA FROM THE WEST TODAY. WK HI PRESS RIDGE TO NOSE IN FROM THE SW ACRS THE REGION TONITE...AS A CF MOVES ACRS THE GREAT LKS REGION. ALSO...A STORM SYS WILL BE INTENSIFYING AS IT TRACKS UP THE EAST COAST TODAY AND TONITE. 09Z RUC SHOWS TEMPS GETTING UP INTO THE 20S IN MOST LOCATIONS TODAY. SW SFC WINDS TO FURTHER DEVELOP IN THE ST LAW VLY TODAY...WITH WINDS MORE WESTERLY ELSEWHERE. LT LES TO PERSIST ACRS NORTHERN NY IN SW FLOW ALOFT THROUGH 18Z TODAY BEFORE WINDS BECOME MORE WESTERLY THIS AFTERNOON...AS THE H5 TROF TO MOVES ON THROUGH. MOST OF THE H85 MOISTURE CONFINED TO THE NORTHERN NY SIDE OF THE FA TODAY. VERY MINIMAL QPF INDICATED BY RUC TODAY IN NORTHERN NY. H85 CAA TO TAKE PLACE THROUGH 00Z TONITE...WITH WK WAA AFTER THAT THROUGH 12Z TUE. HAVE UPPED POPS TO LIKELY TODAY IN THE ADIRONDACKS BASED ON CURRENT RADAR COVERAGE TRENDS. MSS-LAND MOST LIKELY TO STAY OUT OF ANY LES TODAY...SO MENTIONED THAT THE BEST CHC FOR ANY MEASURABLE SN WILL BE IN THE HIR TRRN OF THE ST LAW VLY TODAY. CHC OF FLURRIES LOOKS OK FOR THE REST OF THE FA...ALTHOUGH DOUBT THAT SRN VT WILL SEE ANYTHING AT ALL. WILL SAVE ANY BIG TIME ZONE RE-GROUPINGS FOR THE AFTERNOON PACKAGE. AM HANDICAPPED A LIL TODAY IN FORECASTING TEMPS AS NO MESONET DATA AVAILABLE DUE TO LOCAL COMMS PROBLEMS. WORK ZONES GONE. FINAL ZFP AFTER A FEW TWEAKS AND A QUICK LOOK AT THE LATEST LAMP DATA. .BTV...NONE. MURRAY vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 915 PM EST MON JAN 24 2000 SFC LOW IS OFFSHORE NOW WITH BIGGEST QUESTION STILL THE TRACK AND THE WRN EDGE OF THE PCPN. BEST PRESSURE FALLS HAVE BEEN NNE OF THE SFC LOW. THIS TRACK SHUD TAKE IT ALMOST ACRS HAT BETWEEN 09-12Z. ACCORDING TO NCEP THIS MORE WRN TRACK IS REFLECTED IN THE 18Z AVN RUN. LAST FEW RUNS OF THE RUC ALSO HAVE THE LOW SIGNIFICANTLY FURTHER W THAN THE 12Z AVN AND JUST SLIGHTLY FURTHER W THAN THE 12Z ETA. SO ALL THIS SHUD LEAD TO THE PCPN SHIELD GETTING INTO THE VERY ERN COUNTIES OF THE CWA. ATTM...THE LIGHTER REFLECTIVITY RETURNS ARE ONLY MAKING VERY SLOW PROGRESS NW WHILE THE >20 DBZ ECHOS ARE MOVING FASTER NW. CIGS ARE STEADILY DROPPING ACRS THE ERN AND SRN CWA. SN HAS FINNALY BEGUN AT BUY SO IT LOOKS LIKE IT WL BE ANOTHER HOUR OR TWO BEFORE THE PCPN BEGINS IN DAN. LOOKING AT OBS WHERE THE PCPN HAS ALREADY BEGUN...SOME LOCATIONS IN THE EXTREME SE PART OF THE FA MAY SEE A MIX OF RAIN AND SLEET BEFORE CHANGING OVER TO SNOW. PLAN ON PUTTING IN A WINTER WX ADVISORY FOR 1-3 INCHES OF SNOW IN 6 VA COUNTIES AND 2 NC COUNTIES IN ERN CWA. .RNK VA...WINTER WEATHER ADVISORY TONIGHT VAZ004>047-058-059. WV...NONE. NC...WINTER WEATHER ADVISORY TONIGHT NCZ005-006. AMS va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 917 AM EST TUE JAN 25 2000 LO PRES IS PULLING AWAY TO THE NE THIS AM. ROUGHLY 1-2 INCHES OF WET SLUSHY SNOW IN THE CHS AREA THIS AM...MAYBE A LTL MORE IN FAR INLAND . BACK EDGE OF PCPN HAS CLEARED THE FA AS OF 9 AM. S/S HAS RETURNED TO ALL BUT XTREME NRN ZONES...BUT EXPECT M/SNY SKIES ALL AREAS BEFORE NOON. WL REMOVE ALL PCPN FM ZONES THIS PKG. WINTER WX ADVY IS EXPIRING AND THAT LOOKS JUST FINE. WL GO M/SNY OR BECMG M/SNY FAR N. H85 TEMPS THIS AFT WL RANGE FM -2 TO -4 DEG C NRN ZONES TO 1-2 DEG C SRN ZONES. PLAN ON HIGHS FM MID 40S NORTH TO LOWER 50S SOUTH. WINDS LOOK OK. CWF...BOTH RUC/MESOETA INDICATE NW FLOW DIMINISHING GRADUALLY THIS AFTN. LATEST REPORT FROM CHARLESTON PILOT BOAT INDICATES CONDITIONS ARE ALREADY LAYING DOWN. WILL LOWER GALE WARNING FOR S CAROLINA WATERS AND CONTINUE SCA ELSEWHERE EXCEPT CHS HARBOR. NW FLOW SHOULD ALLOW SEAS NEAR SHORE TO SUBSIDE SUBSTANTIALLY BY LATER TDA. .CHS... SC...SMALL CRAFT ADVISORY S SANTEE RIVER TO SAVANNAH OUT 20 NM EXCLUDING CHARLESTON HARBOR. GA...SMALL CRAFT ADVISORY SAVANNAH TO ALTAMAHA SOUND OUT 60 NM. TJR/RVT sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 958 AM EST TUE JAN 25 2000 WILL LIKELY NEED TO MAKE A FEW MINOR ADJUSTMENTS TO FIRST PERIOD FORECAST...AS CLOUDS ARE QUICKLY INCREASING OVER WESTERN HALVES OF TN AND KY ATTM. 850 THERMAL TROF AXIS ACROSS SWRN VA THIS MORNING WHERE THERE IS ALSO EXTENSIVE SNOW COVER. FACTORING IN CLOUDS FOR THE AFTN AS WELL...SUGGESTS NEED TO LOWER MAX TEMPS DEFINITELY FOR LEE/WISE COUNTIES AND POSSIBLY A FEW AREAS AS WELL. NOTICED THAT TRI WAS RUNNING WELL BEHIND FWC MOS AT 14Z. LATEST RUC MODEL SHOWS COLD AIR ADVECTION (CAA) AT 850 MBS...WHICH FURTHER SUPPORTS LOWERING MAXES. ALONG WITH THE CLOUDS...SOME WEAK SYNOPTIC SCALE FORCING/LIFT DOES DEVELOP BY LATE THIS AFTN...ESPECIALLY UPSLOPE AREAS. MAY INTRODUCE AT LEAST FLURRIES FOR NE PLATEAU INTO LEE/WISE COUNTIES FOR THIS AFTN. OTHERWISE...FOR TONIGHT...WE ARE CONSIDERING SOME LIGHT SNOW ACCUMS FOR AT LEAST NE MTNS...POSSIBLY MEETING ADVISORY CRITERIA. WILL AWAIT THE FULL 12Z MODEL RUNS AND WATCH FOR FURTHER DEVELOPMENT UPSTREAM. MORE ON THIS IN AFTN AFD. .MRX... NC...NONE. TN...NONE. VA...NONE. TG tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 313 AM CST TUE JAN 25 2000 ...GLOBALLY... DEAMPLIFICATION OF THE 3 WAVE PATTERN IS WELL UNDERWAY ACROSS THE HEMISPHERE AS THE POWERFUL ASIAN/PACIFIC JET BEGINS TO FLATTEN THE FLOW. GLOBAL WATER VAPOR MOSAIC SHOWS A 100-120 KNOT JET ENCIRCLES NEARLY THE ENTIRE HEMISPHERE EXCEPT PARTS OF THE EASTERN ATLANTIC. THREE VERY STRONG JET STREAKS OF 150+ KNOTS (BASED ON DARKNESS) WERE EMBEDDED IN THE FLOW...ONE RUNNING ACROSS THE CONUS (RAOB GROUND TRUTH OF 180 KNOTS)...THE SECOND RUNNING FROM EASTERN CHINA TO 165E ...AND THE THIRD RUNNING FROM EGYPT TO INDIA. THE HIGH AMPLITUDE RIDGE INTO ALASKA IS BREAKING DOWN AND HAS MOVED INLAND TO ABOUT ALBERTA. WATER VAPOR SHOWS A CLASSIC LA NINA SETUP IS DEVELOPING AGAIN ACROSS THE PACIFIC FOR AT LEAST THE THIRD TIME THIS WINTER. THE RESULT BEING FAST NEAR ZONAL FLOW ACROSS MOST OF THE PACIFIC INTO THE PAC NORTHWEST WITH STRONG SHORTWAVES EMBEDDED IN THE FLOW. GLOBAL MODELS ARE IN FAIRLY GOOD AGREEMENT ABOUT THIS BUT BEGIN DIVERGING BY THIS WEEKEND AND INTO NEXT WEEK. MODELS CONTINUE TO INDICATE A SPLIT FLOW ACROSS THE CONUS AS THE PAC NORTHWEST RIDGE MOVES ACROSS THE CONTINENT. WITH THE POLAR JET AND SUBTROPICAL JETS WELL REMOVED FROM THE AREA QUIET WEATHER SHOULD PREVAIL FOR QUITE A WHILE. THE PATTERN SHOULD BEGIN REAMPLIFYING AGAIN SHORTLY BEFORE THE MIDDLE OF FEBRUARY. NET RESULT HERE IS BELOW NORMAL TEMPERATURES UNTIL THE WEEKEND WHEN TEMPERATURES MODERATE TOWARD NORMAL. TEMPERATURES NEXT WEEK WILL AVERAGE ABOVE NORMAL. PRECIPITATION TO BE WELL BELOW NORMAL FOR THE REST OF THE THIS WEEK AND SHOULD CONTINUE TO BE BELOW NORMAL FOR A GOOD CHUNK OF NEXT WEEK. ...LOCALLY... WATER VAPOR AND PROFILER DATA SHOW SHORTWAVE MOVING THROUGH THE FORECAST AREA WITH ANOTHER SHORTWAVE DIVING SOUTH TOWARD THE DAKOTAS FROM CANADA. VERY IMPRESSIVE SYSTEMS ON BOTH COASTS WITH THE EAST COAST SYSTEM REALLY WINDING UP. IR AND FOG PRODUCT SHOW A LARGE AREA OF ST/SC MOVING SOUTHEAST ACROSS IOWA/MINNESOTA WITH A BREAK ACROSS THE ARROWHEAD. AHEAD OF THE ST/SC SOME AC/CI WERE NOTED. 06Z SURFACE ANALYSIS HAS A COLD FRONT/TROF JUST EAST OF THE FORECAST AREA WITH A WARM FRONT RUNNING FROM ABOUT KPIA TO KEVV. MOISTURE ANALYSIS SHOWS DEW POINTS IN THE TEENS ACROSS THE AREA WITH SINGLE DIGIT DEW POINTS OVER THE NORTHERN PLAINS. DVN 88D SHOWS WHAT LITTLE --SN/-SN THAT OCCURRED IS MOVING INTO EASTERN/CENTRAL ILLINOIS. PROBLEMS THIS PACKAGE ARE CLOUDS/TEMPERATURES. 00Z MODELS DID NOT INITIALIZE WELL AT ALL AND THIS IS REFLECTED IN THE FORECAST POSITIONS/STRENGTH AT 06Z...ESPECIALLY WITH THE COASTAL SYSTEMS. IN THE IMMEDIATE AREA THE AVN IS PLACING THE SURFACE HIGH THE BEST BUT IS TOO STRONG. THE ETA IS PLACING THE COLD FRONT/TROF THE BEST BUT IS NOT CORRECT WITH THE LOW PLACEMENT AROUND KSSM. ADD TO THIS THE CLEARING THAT NONE OF THE MODELS ARE SHOWING ACROSS THE ARROWHEAD INTO NORTHERN WISCONSIN. THEREFORE WILL GO WITH THE RUC AND SATELLITE TRENDS FOR IMMEDIATE SHORT TERM AND THEN BLEND IT AS BEST AS ONE CAN INTO A PROBABLE AVN/ETA COMPROMISE. SATELLITE TRENDS AND RUC INDICATE CLOUDS TO OVERSPREAD MOST OF THE AREA BY SUNRISE WITH THE WINDS PICKING UP AS DOWNWARD MOTION ALLOWS HIGHER MOMENTUM AIR ALOFT TO MIX DOWN. PER SATELLITE ABOUT THE NORTHEAST THIRD OF THE FORECAST AREA SHOULD BREAK OUT OF THE CLOUDS AT SOME POINT IN THE AFTERNOON. RUC 925/850 MB TEMPERATURES INDICATE NOT MUCH CAA TO TAKE PLACE DURING THE FIRST HALF OF THE MORNING BUT THEN BEGINS TO DEVELOP IN ERNEST BY 18Z. ETA/AVN SHOW THIS AS WELL. THEREFORE TEMPERATURES SHOULD RISE JUST SLIGHTLY THIS MORNING BEFORE STARTING A SLOW FALL FOR THE REST OF THE DAY. ONLY PROBLEM WITH THIS WOULD BE SEEING MORE SUN THAN EXPECTED WHICH WOULD STEADY TEMPERATURES OUT SOMEWHAT GIVEN MODELS SHOWING STRONG DOWNWARD MOTION ACROSS THE AREA WITH TIME SECTIONS INDICATING NOT MUCH MOISTURE ABOVE 800 MB. SURROUNDING 88D SITES UPSTREAM INDICATE SOME --SN OCCURINGSO WILL THROW IN A MENTION OF A FEW FLURRIES AS WELL. TONIGHT CLEARING TO OCCUR WITH WINDS DIMINISHING AND CONTINUED CAA. SNOW FIELD SHOULD AID IN LOWERING TEMPERATURES A BIT MORE AS WELL AS THE CANADIAN HIGH BUILDS IN. HIGH PRESSURE TO REMAIN IN CONTROL FOR THE REMAINDER OF THE PACKAGE WITH A SMALL INCREASE IN CLOUDS WEDNESDAY AS RH FROM NEXT SYSTEM INVADES THE AREA SOMEWHAT. FWC/FAN ARE SOMEWHAT CLOSE BUT THE COOLER FAN NUMBERS MAY BE A LITTLE BETTER OVER FWC. ...EXTENDED... WILL NOT TOUCH EXTENDED DUE TO RUNNING WELL BEHIND. QUICK LOOK AT IT COMPARED TO ECMWF/GEM MODEL SUGGESTS IT IS ON TRACK. COORDINATED WITH DSM...LSE...CHI...ILX...AND STL. .DVN...NONE. NC il MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 947 AM PST TUE JAN 25 2000 SYNOPSIS...A PACIFIC LOW PRESSURE SYSTEM AND SURFACE COLD FRONT WILL MOVE ACROSS CALIFORNIA TODAY AND INTO NEVADA TONIGHT. THIS SYSTEM WILL INTERACT WITH A PLUME OF VERY MOIST SUBTROPICAL AIR FLOWING INTO THE REGION TO PRODUCE AREAS OF LOWER ELEVATION RAIN AND MOUNTAIN SNOW TODAY. FOR MANY AREAS THIS WILL BE THE FIRST SIGNIFICANT PRECIPITATION SINCE SEPTEMBER. DRIER WEATHER IS EXPECTED TONIGHT AND WEDNESDAY. DISCUSSION...MOISTURE PLUME LOSING SOME HIGH LEVEL MOISTURE BUT STILL TRANSLATING EASTWARD THROUGH FORECAST AREA. DYNAMIC LIFT SO FAR HAS BEEN FAIRLY LIGHT WITH MOST PRECIPITATION DUE SIMPLY TO OROGRAPHIC LIFT WHICH HAS PRODUCED 7 INCHES AT ASPENDELL IN LEE OF SIERRA AND 1.5 TO 3 INCHES IN SPRING MOUNTAINS; SNOW LEVELS REMAIN NEAR 8000 FEET. PLUME HAS SHIFTED FAR ENOUGH AWAY FROM THE SOUTHERN SIERRA THAT WE ARE CANCELLING THE ADVISORY FOR THAT AREA BUT WILL HOLD ON TO THE ONE FOR SOUTHERN NEVADA MOUNTAINS. MESO ETA AND RUC MODELS AGREE WITH OTHER LOWER RESOLUTION MODELS MAINTAINING SOME DEGREE OF LAYERED MOISTURE INTO EARLY EVENING ACROSS EASTERN 2/3 OF FORECAST AREA WHILE DYNAMIC LIFT PEAKS AROUND 21Z - 03Z THIS AFTERNOON AS A RESULT OF RIGHT ENTRANCE REGION JET LIFT AND ALSO HINT OF UPPER LEVEL DIFFERENTIAL VORTICITY ADVECTION. MEANWHILE...MODELS INDICATE MAXIMUM LIFT LATER TODAY AND EARLY TONIGHT ACROSS NORTHERN NYE AND LINCOLN COUNTIES AS THE TROP FOLD...SUCH AS IT IS...TRANSLATES ACROSS REGION. LAYERED MOISTURE IS DECREASING DURING THAT PERIOD BUT ENOUGH TO MAINTAIN HIGH CHANCES FOR LIGHT PRECIPITATION. BELIEVE PRECIPITATION CHANCES WILL DIMINISH SOUTHERN NEVADA/CALIFORNIA BY 03Z AS ISENTROPIC UPGLIDE NEUTRALIZES AND BECOMES A GENTLE DOWNGLIDE. WILL HANG ON TO BETTER CHANCES LATER TONIGHT ACROSS NORTHWEST ARIZONA...OF COURSE. POTENTIAL BIG CHANGES ON TAP FOR THE GOING EXTENDED FORECAST...IN THE WAY OF MUCH LESS OF A STORM SYSTEM FOR LATE THURSDAY/FRIDAY IN THE SOUTHWEST...IF THE NEW AVN IS TO BE BELIEVED. WILL ADDRESS THIS ISSUE FOR THE AFTERNOON PACKAGE. MCQUEEN .LAS...A SNOW ADVISORY IS IN EFFECT TODAY FOR NVZ018-019. SEE THE LATEST RNOSWSLAS FOR DETAILS. nv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 225 PM EST TUE JAN 25 2000 INITIAL BAND OF PRECIP WHICH BROUGHT 2-5 INCHES OF SNOW TO CENTRAL AND SOUTHERN VERMONT TODAY HAS WEAKENED SOMEWHAT AND DON'T EXPECT SIMILAR ACCUMULATIONS THIS AFTERNOON IN NORTHWESTERN VERMONT AND NORTHERN NEW YORK. AS A MATTER OF FACT...THERE SEEMS TO BE VERY LITTLE PRECIP IN SOUTHERN NEW ENGLAND WHICH MIGHT AFFECT OUR AREA THE REMAINDER OF THE AFTERNOON. THIS EVENING HOWEVER...RUC AND ETA SUGGEST A TIGHTENING 850-700 MB THERMAL GRADIENT FROM NORTHERN VERMONT SOUTHWESTWARD THROUGH THE ALBANY NY AREA. THIS BENT-BACK WARM FRONT OUGHT TO BE THE FOCUS FOR THE GREATEST PRECIP IN THE 00-09 UTC PERIOD. THUS WILL CONTINUE THE WARNING FOR ALL AREAS EXCEPT ST. LAWRENCE VALLEY WHERE LOW-END ADVISORY SNOWFALL AMOUNTS SHOULD SUFFICE. HOWEVER...ALL BETS ARE OFF IF TOO MUCH DRY AIR WRAPS AROUND THE NORTHWESTERN SECTOR OF THE CYCLONE. WILL HOLD MIN TEMPERATURES IN THE TEENS OVERNIGHT. AS SURFACE CYCLONE MOVES INTO THE GULF OF MAINE...SOME QUESTION AS TO HOW RAPIDLY THE SNOW WILL DIMINISH IN NORTHERN VERMONT ON WEDNESDAY. AFTER CHATTING WITH WFO PORTLAND...HAVE DECIDED TO ONLY HANG ON TO ANOTHER 1-2 INCHES WEDNESDAY MORNING BEFORE TAPERING TO SHOWERS. COLD ADVECTION TAKES OVER WEDNESDAY AFTERNOON AS LOW-LEVEL FLOW SHIFTS TO NORTHWESTERLY. MORNING TEMPERATURES IN THE 15-25F RANGE... BUT LIKELY TO BE FALLING IN THE AFTERNOON. UPPER CYCLONE CUTS OFF OVER NY/PA WEDNESDAY NIGHT AND WOBBLES NORTHEASTWARD ON THURSDAY. EXPECT PLENTY OF CLOUD COVER AND A CHANCE OF SHOWERS THROUGH THURSDAY AS CYCLONIC FLOW ALOFT CONTINUES AND THE COLD DOME ADVECTS INTO THE REGION. AVN/ETA SURFACE WINDS INCREASE DURING THROUGH THURSDAY WITH TEMPERATURES SINKING BACK INTO THE SINGLE DIGITS AND TEENS. 3 TO 5 DAY...UPPER TROUGH EVENTUALLY REPLACED BY AN AMPLIFYING RIDGE WHICH HOLDS THE NORTHEASTERN U.S. UNDER A LARGE SURFACE ANTICYCLONE. TEMPERATURES WILL BE COLD INITIALLY...BUT WARM BY SUNDAY AS THE SURFACE RIDGE AXIS PASSES TO OUR EAST. ST. JEAN .BTV...WINTER STORM WARNING TONIGHT VT ZONES 01-12 AND NY ZONES 28>31 AND 34-35. WINTER WEATHER ADVISORY TONIGHT NY ZONES 26-27. vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 235 PM CST TUE JAN 25 2000 PRIMARY FORECAST CONCERNS...CLOUD TRENDS AND TEMPERATURES. VISIBLE SATELLITE IMAGERY SHOWED CLOUDS GENERATING OFF OF LAKE SUPERIOR AND ADVANCING SOUTHWARD ACROSS OUR FORECAST AREA. THESE CLOUDS LOOKED CELLULAR AND SOME BURSTS OF LIGHT SNOW NOTED A TIMES...BUT THIS VERY ISOLATED AND TEMPORAL IN NATURE. SURFACE ANALYSIS INDICATED HIGH PRESSURE BUILDING ACROSS THE PLAINS...WHILE UPPER AIR ANALYSIS SHOWED 850 MB TEMPERATURES BETWEEN MINUS 15C AND MINUS 18C. LOW LEVEL RELATIVE HUMIDITY IN LATEST RUC SHOWED VALUES 70 PERCENT OR ABOVE CONTINUING TONIGHT OVER THE CENTRAL AND NORTH CENTRAL WI ZONES. THIS SHOULD RESULT IN SOME LINGERING CLOUDS IN THESE AREAS. ELSEWHERE... EXPECT CLOUDS TO DISSIPATE THIS EVENING AFTER SUN SETS. REST OF PERIOD...FEW CLOUDS ANTICIPATED AS SHOWN BY TIME/HEIGHT CROSS SECTIONS. TEMPERATURES WERE PROBLEMATIC WITH 850 MB READINGS GRADUALLY RISING TO AROUND MINUS 8C BY THURSDAY. FWC AND FAN GUIDANCE RESPONDING WITH INCREASING VALUES. ALL MODELS INDICATED SURFACE HIGH BUILDS IN AND REMAINS OVER THE UPPER MISSISSIPPI VALLEY NEXT FEW DAYS. LIGHT WINDS AND MOSTLY CLEAR SKY WILL RESULT IN STRONG NOCTURNAL INVERSION IN SPITE OF TEMPERATURES WARMING ALOFT. IN ADDITION...TROUGH REMAINING OVER THE EAST COAST WILL SLOW DOWN PROGRESSION OF WEST-EAST SYSTEMS...PRECLUDING AS FAST A WARM UP AS PERHAPS THE GUIDANCE SUGGESTS. THEREFORE...WILL GO AT OR BELOW GUIDANCE...ESPECIALLY AT NIGHT...DUE TO SNOW COVER...NEUTRAL ADVECTION AND STRONG INVERSION. ANTICIPATING GENERALLY SINGLE DIGITS BELOW ZERO TONIGHT...ZERO TO 10 BELOW WEDNESDAY NIGHT. IN FACT...COLDEST READINGS WEDNESDAY NIGHT SHOULD BE IN WI ZONES WITH HIGH SITUATED OVER THE AREA AND COLD AIR DRAINAGE INTO VALLEYS. HIGHS WEDNESDAY/THURSDAY SHOULD BE MAINLY IN THE TEENS TO LOWER 20S. THANKS FOR COORDINATION WITH DLH AND GRB. .LSE...NONE. THOMPSON wi