EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 300 AM PST TUE FEB 29 2000 A WEAK PACIFIC STORM WILL MOVE INLAND ACROSS CENTRAL CALIFORNIA TODAY BRINGING A CHANCE OF SHOWERS TO SOUTHWEST CALIFORNIA THIS AFTERNOON AND TONIGHT WITH GUSTY WINDS FOR THE MOUNTAINS AND DESERTS. A SECOND PACIFIC STORM WILL BRING ANOTHER CHANCE OF SHOWERS THURSDAY AFTERNOON THROUGH FRIDAY MORNING. AVN/MRF PREFERRED THRU THE NEXT FIVE DAYS. IN THE NR TERM...ACARS SOUNDINGS AND RAOBS SHOWED A SUBSIDENCE INVERSION BETWEEN 5K AND 6K FT MSL WITH SOME LOW CLOUDS BANKED UP ALG THE CSTL SLOPES OF THE SBD/RIV COUNTY MTNS BLO THIS INVERSION MON EVENING. THESE CLOUDS HAVE SINCE DISSIPATED. AN EARLY MON EVENING HIGH RESOLUTION ACARS SOUNDING FROM SNA SHOWED A WK MARINE INVERSION TRYING TO FORM AROUND 1500 FT. COAMPS SHOWS A WK CSTL EDDY THIS MORNING...CONFIRMED WITH SURFACE REPORTS...WITH BOTH COAMPS AND RUC SHOWING A WK CSTL EDDY FOR WED MORNING THOUGH DIFFERING ON THE DETAILS FOR WED MORNING. AREAS NEAR THE CST MAY SEE SOME PATCHY STRATUS...OTHERWISE INCREASING CLOUDINESS FOR SW CA TODAY AS A WK PAC STORM MOVES INLAND INTO CNTRL CA. BEST CHANCE FOR SHOWERS WL BE NRN RANGES (SBD/RIV COUNTY MTNS) THIS AFTERNOON AND EVENING WITH LESSER CHANCES ELSEWHERE LATE THIS AFTERNOON AND EVENING. AVN 850 MB RH IS SUPPORTIVE OF A BRIEF PD OF LIGHT SHOWERS LATE AFTERNOON EARLY EVENING FOR MOST AREAS ALG AND W OF MTNS...BUT AMOUNTS SHOULD BE LIGHT AWAY FM HIGHER TRRN. QPF WL BE LESS THAN FOR SUN STORM... QUARTER INCH OR LESS CSTL SXNS TO ONE QUARTER TO LCL ONE HALF INCH NRN RANGES. WITH SNOW LVLS STARTING OUT LWR THAN FOR SUN STORM... GREATER PERCENTAGE OF QPF WL GO INTO SNOW FOR NRN RANGES...BUT PROBABLY NOT SUFFICENT FOR WINTER WEATHER ADV...HENCE HAVE WORDED LCL SNOW ACCUMULATIONS LESS THAN 4 INCHES ABV 5000 FT FOR SBD/RIV COUNTY MTNS. THU SYS LOOKS A LTL WETTER...COMPARABLE OR SLIGHTLY LESS THAN AMOUNTS FOR SUN STORM. EXTENDED MDLS CONTINUE TO ADVERTISE A MORE SUBSTANTIAL STORM FOR SAT NIGHT AND SUNDAY... LINGERING INTO MON...BUT THIS IS STILL BEYOND THE CURRENT EXTENDED PD. SAN 230 .SAN...NONE. MARTIN ca NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 245 PM MST TUE FEB 29 2000 SHORT TERM DISCUSSION: SKIES SHOULD BE NEARLY CLEAR OVERNIGHT... THOUGH SOME CI MAY START TO MOVE IN LATE. PRESSURE GRADIENT WILL BE FLAT GOING TO LIGHT SOUTHERLY SO ONLY LIGHT DRAINAGE WINDS ARE EXPECTED. TEMPERATURES HAVE WARMED A BIT MORE THAN EXPECTED TODAY...BUT I WILL STILL UNDERCUT GUIDANCE LOWS A BIT. GIMMESTAD LONG TERM DISCUSSION: ANOTHER SYSTEM MISSES THE FRONT RANGE LEAVING US ZERO FOR THE LAST TWO AS WE PUT OUR SPRINGLIKE FEB TO REST. A NUMBER OF CHANCES FOR PCPN IN THE NEXT 10 DAYS AS SYSTEMS MOVE RAPIDLY ACRS THE PACIFIC INTO THE WRN US WITH AN ANCHORED MEAN TROF IN THE NORTH PACIFIC. QUESTION IS NOW THAT MARCH IS HERE CAN WE PUT ALL THOSE FEB MISSES BEHIND US AND GET OUR REAL WINTER GOING. THE ANSWER IN THE SHORT TERM IS BY NO MEANS CERTAIN AS THE NEXT EVENT HOLDS A NUMBER OF QUESTIONS FOR THURSDAY. THE SYSTEM IS ON THE W COAST ATTM WITH A NRN PORTION ROTATING INTO THE PAC NW AND A SRN PTN DRIVING TWDS SRN CALIF ON THE STRENGTH OF A 120KT PLUS JET ON ITS BACKSIDE. COMPARISON OF THE MODEL FCSTS INDICATES THE MAIN DIFFERENCE IS THE ETA DROPS THE SYSTEM FARTHEST SOUTH BY 12Z THU WITH A CLOSED LOW IN CTRL NM AND LITTLE IN THE WAY OF UPSLOPE OR FORCING FM DEN NORTH. AVN TRENDING FARTHER S AS WELL WITH GREATER THREAT OF SIG PCPN FOR SERN CO BUT STILL ENUF FOR UPSLOPE AND CHC OF SNOW OUR AREA...VS PROBABLY A MISS ON THE ETA. INITIAL ANALYSES INDC ETA HAS A STRONGER JET ON THE W SIDE OF THE SYSTEM THAN THE OTHER TWO MODELS BUT NO OBS TO TELL WHICH IS CORRECT. NOT SURE IF RUC ANALYSES HAVE ENUF ACARS TO KNOW STRUCTURE OF THE JET OFF CALIF COAST...BUT 6H ETA FCST DOES MATCH UP BETTER THAN OTHER MODELS IN TERMS OF JET. ON THE OTHER HAND LATER CUTOFF FOR AVN/NGM VS ETA MIGHT MEAN BETTER DATA UPSTREAM SO REALLY LEFT WITH NO REASON TO NECESSARILY BELIEVE MORE SRN ETA TRACK OVR AVN/NGM FOR UPR LVL SYSTEM. AHEAD OF THE SYSTEM HI PRES WILL PUSH S OVNGT AND SET UP RETURN FLOW ON WED...TOO BAD THE HI ISN'T TIMED FOR THU IN WCH CASE WUD HAVE MORE CONFIDENCE IN SNOW FOR NERN CO. WITH RETURN FLOW WED LUK FOR A MILD DAY AND LIKELY DENVER CYCLONE SETTING UP. DWPNTS WILL TAKE AWHILE TO BUILD UP BUT WITH INCRS IN UPR LVL FORCING LATE IN THE DAY WILL PUT SOME CHC OF RAIN SHOWERS ON THE PLAINS BY LATE AFTN. RAIN/SNOW WILL BE AN ISSUE AGAIN FOR WED NIGHT BUT SHOULD WE ACTUALLY GET A DEEP MOIST UPSLOPE LIKE THE AVN SHOWS THEN IT SHOULD BE COLD ENUF FOR SNOW ON THE PLAINS ON THU. IF THE SYSTEM DOES HOWEVER GO FARTHER S THEN NOT ONLY WILL CHC OF PCPN GO DOWN BUT THREAT OF RAIN SHWRS INSTEAD OF SNOW WILL BE A REAL POSSIBILITY. LOTS OF UNCERTAINTY...ATTM DOES NOT LUK LIKE A BIG EVENT FOR THE NE BECAUSE OF THE MORE SRN TRACK...A SYSTEM THAT ISN'T TERRIBLY POTENT...AND AN ILL-TIMED HI PRES SYSTEM FROM THE NORTH. STILL...IF THE UPR LO IS FURTHER N AND TAKES A NE TURN AS IN THE AVN FCST FOR THU...THEN NERN CO CUD STILL GET A DECENT EVENT OUT OF THIS. FOR NOW WILL KEEP THINGS IFFY WITH BETTER CHC OF PCPN FARTHER E. NOT AN ESPECIALLY FAVORABLE FLOW FOR THE MTNS AND ATTM MAY GET THRU EVENT WITHOUT NEED TO HOIST ANY MTN HILITES. LONGER TERM THE MRF APPEARED TO BE TOO FAST W NEXT SYSTEM WHEN COMPARED WITH THE CAN..UK AND EC WCH WITH THEIR SLOWER MVMNT WUD KEEP SAT MAINLY DRY. HOWEVER NEW AVN AND CANADIAN 72H AGREES EXACTLY WITH SPEED OF MRF...SO WENT AND PUT SOME PCPN IN FOR SAT. HOWEVER THIS NEXT SYSTEM ATTM DOES NOT LUK WELL ORGANIZED SO WILL WORD AS SLGT CHC FOR THE PLAINS AND HAVE RAIN OR SNOW PSBLTIES. SZOKE .DEN...NONE. co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KEY WEST FL 955 AM EST TUE FEB 29 2000 CURRENTLY... SATELLITE LOOPS SHOW NNE-SSW ORIENTED LINE OF CLOUDS FROM FLORIDA BAY ACROSS MIDDLE KEYS TO NW COAST OF CUBA...MOVING WEST...WITH RADAR INDICATING ISOLATED LIGHT SHOWERS WITHIN THIS FEATURE. SURFACE ANALYSIS PLACES SURFACE WINDS NE OVER WEST SIDE OF THE FEATURE AND ENE ON THE EAST SIDE OF IT. THIS CONVERGENT BOUNDARY IS THE SAME FEATURE SEEN FARTHER EAST THIS TIME YESTERDAY....FROM BIMINI SW OVER THE EASTERN EDGES OF THE FLORIDA STRAITS TO N COAST OF CUBA. C-MAN STATIONS REFLECT ABOVE MENTIONED WIND DIRECTIONS...AND SO FAR SPEEDS ARE NEAR 10 KNOTS. THE WEAK COLD FRONT THAT WAS MOVING SOUTH INTO THE SOUTHERN PENINSULA YESTERDAY IS NOT READILY DISCERNIBLE ON VISIBLE SATELLITE THIS MORNING. FIRST PERIOD FORECASTS... THE 1030 AM COASTAL MARINE FORECAST WILL ACKNOWLEDGE THE ONGOING WIND VEERING THAT IS OCCURRING AS FORECASTED...WITH WINDS NOW NE TO E AT ALL BUT DRY TORTUGAS WHICH IS STILL MORE NORTHERLY. LOOKING AT LATEST RUC AND MESO-ETA...AS WELL AS OBS IN THE BAHAMAS...I MAY TEMPER FORECAST WIND SPEED DOWN TO 10 KNOTS FOR THE AFTERNOON. LOWER KEYS ARE STILL QUITE SUNNY...BUT WESTWARD PROGRESS OF THE CONVERGENCE LINE MAKES PARTLY CLOUDY WITH ISOLATED SHOWERS STILL LOOK LIKE A GOOD FORECAST. ALREADY IT HAS BEEN PARTLY CLOUDY OVER MID AND UPPER KEYS. NO CHANGES ARE ANTICIPATED FOR THE PUBLIC ZONE FORECASTS. .EYW...NONE. CLB fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 205 PM CST TUE FEB 29 2000 UPPER LOW OVER NCNTRL KS AT 19Z. SFC MAP SHOWED COLD FRONT EXTENDED FROM NEAR KTOP TO KTUL TO KDWF. NEWLY DEVELOPED CONVECTION NEAR THE UPPER LOW OVER NE KANSAS. LATEST RUC AND WIND PROFILERS SHOW THE SYSTEM IS NEARLY STACKED. MAIN FCST ISSUE WILL BE CHC OF SHRA/TSRA TONIGHT. ETA/AVN/NGM ALL SIMILAR IN MOVG THE CLOSED CIRCULATION NE OVER MISSOURI INTO ILLINOIS TONIGHT...WITH THE SYSTEM WEAKENING SLIGHTLY AND OPENING UP. 12Z UPPER AIR AT 850MB AND LATEST SATELLITE/RUC SHOW GOOD LOW LEVEL MOISTURE ADVECTING NE INTO MISSOURI. BEHIND THE MOIST AXIS WHERE THE CU FIELD IS OVER WESTERN MISSOURI IS WHERE WE WILL NEED TO MONITOR FOR CONVECTION...JUST AHEAD OF THE LOW TROP THERMAL RIDGE. THE SYSTEM IS FORECAST TO ACCELERATE A BIT AS IT OPENS UP. PROFILERS SHOW NEAR 100KT 500MB FLOW OVER EAST KS. MID-LVL JET STREAK WILL MOVE EAST...WITH OUR AREA IN FAVORABLE RIGHT ENTRANCE REGION OF THE UPPER JET. THIS SUPPORTS GOOD UVM FIELD AS LOW-TROP THETA-E/WAA TO BE ONGOING THROUGH THE EVENING WHILE SHIFTING EAST. SO...WILL MAINTAIN LOW POPS SIMILAR TO ONGOING ZFP. 1000-500MB MEAN RH ONLY AVERAGES 50-60%...WITH K-INDICES MAYBE AS HIGH AS THE LOWER 20S. SO SCT/CHC POPS WILL BE USED. WILL KEEP MENTION OF TSRA...AS STEEPENING LAPSE RATES...ELEVATED DESTABILIZATION OCCURS FROM WEST TO EAST. WILL GO ABOVE GUIDANCE TONIGHT FOR LOWS...AS A GOOD SW WIND HOLDS UP TEMPS...WHILE THERMAL RIDGE NEAR SURFACE LIES OVER THE AREA. QUIET WEATHER WEDNESDAY THROUGH THURSDAY. LARGE AREA OF SFC HIGH PRES WILL BUILD INTO THE REGION. AVN/NGM BOTH ADVERTISE A VARYING AMOUNT OF HIGH CLOUD COVER WILL BE THE RULE...WITH MID/HIGH LEVEL MOISTURE INCREASING CONSIDERABLY ON THURSDAY AHEAD OF THE NEXT IN THE SERIES OF STORM SYSTEMS. WILL TREND WITH COOLER GUIDANCE NOS SINCE SFC RIDGE FORECAST TO BE FAIRLY PROMINENT THROUGH THURSDAY. PER THE AVN AND MRF...WILL INTRODUCE A RAIN DEVELOPING SCENARIO FOR THURSDAY NIGHT AS LOW-LEVEL WAA AND ISENTROPIC UPGLIDE SUPPLY LIFT OF INCREASING LOW AND MID LEVEL MOISTURE. FOR FRIDAY AND SATURDAY...THE NOGAPS SEEMS OUT ON IT'S OWN WITH A MORE SOUTHERN STREAM SYSTEM. WILL GO WITH THE MORE CONSISTENT MRF...AS IT LINES UP A LITTLE BETTER WITH THE ECMWF. THE MAIN SFC AND UPPER AIR SYSTEMS TO MOVE THROUGH ON FRIDAY...WITH SHRA/POSSIBLE TSRA. THE RAIN SHOULD WIND DOWN FRIDAY NIGHT AS THE SYSTEM DEPARTS..LEAVING MAINLY QUIET WX ON SATURDAY. YET ANOTHER SYSTEM MOVES IN ON SUNDAY...SO WILL INCREASE CLOUDS. .PAH...NONE. CN ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 912 PM CST TUE FEB 29 2000 EVENING ANALYSIS HAS DRY LINE FROM NORTHWEST OF TXK TO NEAR ACT...WITH COLD FRONT FROM NORTHEAST OK TO SOUTH OF SPS. DRY LINE HAS SLOWED DOWN OVER THE NORTHERN SECTIONS AND HAS EVEN WORKED BACK NORTH AND WEST A LITTLE FROM CRS TO ACT. LATEST RUC INDICATES DRY LINE WILL BE SLOW TO MOVE EAST OVER NIGHT...AND ONLY EXTENDING FROM EAST OF TXK TO NEAR GGG BY 09Z. THE 00Z ETA GOES ALONG WITH THIS...HAVING THE FRONT FROM BETWEEN SHV AND MLU TO NORTH OF LFK AT 12Z. UPPER LOW OVER NORTHERN MO AND MOVING AWAY FROM THE CWA. SHOWERS THAT DEVELOPED ALONG THE DRY LINE ARE DECREASING...WILL UPDATE SHORTLY TO REMOVE POPS IF CURRENT TREND CONTINUES. WILL ALSO NEED TO ADJUST SKY AND TEMPS EAST OF DRY LINE FOR TONIGHT. .SHV...NONE. IV la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1100 PM EST TUE FEB 29 2000 FCST CONCERNS ARE INVADING RA FM SOUTH AND CAA WITH FROPA FM WEST. SRN AND NRN STREAM SYSTEMS NEAR FA ARE COMBINING TO BRING SPRINGLIKE WX TO ERN UPR MI WITH A RETURN TO SOMEWHAT WINTERLIKE CONDS ON TAP FOR WRN UPR MI. MQT 88D SHOWING LGT RA BEGINNING TO OVERSPREAD THE ERN HALF OF UPR MI. NATIONAL RADAR COMPOSITE SHOWS THIS IS LEADING EDGE OF A RAIN SHIELD ASSOCIATED W/ COMPACT YET POTENT SYSTEM NOW PUSHING NORTH OUT OF MO. COMPLICATING MATTERS IS COLD FRNT ADVANCING INTO UPR MI FM WEST. AS OF 03Z SFC ANALYSIS FRNT IS FM SFC LOW NEAR CYPL ONTARIO TO CMX SOUTH TO LSE AND INTO OTHER SFC LOW NEAR MLI. IR SAT SHOWS LOW STRATUS DECK WITH CAA BEHIND FRNT ALREADY THROUGH DLH AND CKC. HOWEVER...ANY PRECIP WITH THE FROPA IS LIMITED TO LIFT W/ VORT LOBE OVR SWRN ONTARIO ATTM PER WV LOOP AND THAT HAS GENERALLY BEEN LIGHT (-SN WITH VSBY OF 10-15SM). APPEARS THAT MOST OF ACTION TONIGHT WL BE EAST OF A IMT TO MQT LINE AS BEST H7 OMEGA...AND H3 DIVERGENCE IS LOCATED HERE PER 18Z ETA. 18Z ETA ALSO HAS BEST HANDLE ON QPF AS 21Z RUC WAS HESITANT TO SPREAD PRECIP SO FAR NORTH THROUGH 06Z. POSS OF ELEVATED CONVECTION WAS ALSO THOUGHT OF ESPECIALLY AFTER GRB OB AT 02Z REPORTED TSRA...HOWEVER DUE TO LACK OF LGTNG WITHIN LAST HOUR...GENERAL WEAKENING TREND OF SHRTWV...AND LACK OF STABILITY INDICES THAT WOULD SUGGEST OTHERWISE (H7-H5 LAPSE RATES AOB 6 C/KM) HAVE OPTED TO LEAVE OUT THUNDER FOR MOST OF THE U.P...THE EXCEPTION IS SRN MNM COUNTY AS THEY COULD STILL BE NEAR BEST DYNAMIC INSTABILITY AS SHRTWV PRESSES NORTHEAST. AS FRNT SWEEPS ACROSS UPR MI OVERNIGHT ANY LINGERING RAIN IN CENTRAL ZONES COULD CHANGE OVR TO SNOW BEFORE ENDING...AS 1000-850 THICKNESS OF 1305M CROSSES CNTRL U.P. BY 12Z WED PER 18Z ETA. FCST SOUNDINGS FM RUC AND ETA ALSO SUPPORT THIS...HOWEVER H5 VORT MAX AND H7 OMEGA ARE QUICKLY EXITING TO EAST BY THIS TIME SO NO ACCUMS ARE EXPECTED. IN THE WEST AS VORT LOBE OVR SW ONTARIO MV TO WRN UPR MI BY 12Z PER ETA...WINDS SHIFT TO WNW BEHIND FROPA...AND H8 TEMPS DROP TO -8 C PER 18Z AND 00Z ETA...SOME LK ENHANCEMENT COULD COMMENCE AND LAST INTO THE MORNING HOURS...ESPECIALLY IN WNW FAVORED ONT COUNTY UP INTO THE KEWEENAW. .MQT...GALE WARNING LAKE SUPERIOR FOR WED. JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 940 PM TUE FEB 29 2000 CURRENT RADAR/SATELLITE AND 00Z UPPER AIR ALL SUPPORT A HIGH LIKELIHOOD OF SHOWERS AND A FEW TSTMS TONIGHT. IR LOOP SHOWS COOLING CLOUD TOPS OVER SW MI WITH GOOD ISENTROPIC LIFT OCCURRING. LATEST RUC SHOWS CONDENSATION PRESSURE DEFICITS DROPPING THIS EVENING... AND SHOWERS ARE FORMING RAPIDLY ON RADAR. WHILE THIS BATCH OF WAA SHOWERS WILL LIKELY PROGRESS QUICKLY OFF TO THE EAST AND MAY NOT BE AROUND TOO LONG... THE SHOWERS ASSOCIATED WITH THE UPPER DYNAMICS SHOULD MOVE IN BEHIND THEM. BATCH OF CONVECTION CURRENTLY AFFECTING W CNTRL IL EXTRAPOLATES INTO SW MI AROUND 07Z. SEE NO REASON TO CHANGE MUCH IN THE GOING FCST OTHER THAN TO MAYBE BUMP POPS UP OR JUST USE AREAL QUALIFIERS. WILL NOT MESS WITH TEMPS DESPITE CURRENT MILD READINGS IN SLY FLOW. WITH DEWPOINTS IN THE LOWER 30S ATTM... SFC TEMPS SHOULD COOL DRAMATICALLY ONCE THE RAIN MOVES IN. .GRR...NONE. MEADE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 940 AM TUE FEB 29 2000 CURRENT ZONE FORECAST LOOKS OKAY... AND WILL ONLY MAKE SOME MINOR CHANGES. LATEST SATELLITE IMAGERY AND DATA FROM THE 12Z RUC SHOW MOST OF THE MID AND HIGH CLOUDS WILL BE CONFINED TO THE NORTHERN COUNTIES THIS AFTERNOON. WILL KEEP THE PARTLY SUNNY FORECAST GOING IN THOSE LOCATIONS... AND CHANGE TO A MORE OPTIMISTIC PARTLY CLOUDY FORECAST TO THE SOUTH. MODIFIED 12Z SOUNDINGS GENERALLY AGREE WITH THE CURRENTLY FORECAST TEMPERATURES... SO WILL LEAVE THOSE NUMBERS ALONE. ZONES WILL BE OUT BY 1015 AM. TRH .GRR...NONE. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 200 PM CST TUE FEB 29 2000 LARGE AREA SC ROTATING ARND LOW EAST OF LK WINN. RUC 1000/850 LYR RH OUTLINES THIS AREA REASONABLY WELL WITH THE 50-60 PCT LINE. EWD PROGRESS APPEARS TO BE DELAYED FOR NOW AS NERN CWA HAS WARMED UP CONSIDERABLY AND LOWERED LOLVL RH VALUES. EXPECT TO SEE ADVANCE RESUMED BY SUNSET. USING ETA TO FOLLOW THRU THIS EVE AND INTO WED...LOOKING FOR CLEARING AGN ARND MIDDAY. CURRENT ZFP PKG REFLECTS THIS WTH MOCLDY FOR TNGT. QUES REMAINS WHETHER OR NOT TO LEAVE MENTION OF FLURRIES IN FCST. MSTR WILL BE RATHER SHALLOW...BUT UPR TROF/VORT MAX SHOULD PROVIDE ENUF LIFT FOR AT LEAST A FEW OVNGT SNOWFLAKES. MODEL POPS AND QPF PRETTY SKIMPY...SO WILL STAY WTH MENTION OF FLURRIES AND NO POPS. WILL CLEAR OUT CWA FROM W ON WED AS HIGH PRESS MOVES IN...ALLOWING FOR SOME DELAY IN NWRN WI FOR THE MRNG HRS. FAN AND FWC TEMPS QUITE CLOSE...BUT MAY BE TOO LOW CONSIDERING CLD CVR...CURRENT DEW PTS...AND RECORD HIGHS EXPERIENCED TDA JUST PRIOR TO ARRIVAL OF CLD DECK. WILL PRBLY LOWER GUIDNC TEMPS A NOTCH OR TWO. .DLH...NONE. ERF mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 825 PM TUE FEB 29 2000 DISC: 01Z SFC ANALYSIS SHOWS HI PRES ALNG/OFF THE SE CST. LOW PRES AND ASSOCIATED CDFNT ACRS MS RVR VALLEY. SATELLITE SHOWS SOME HI CLDS ZIPPING ACRS THE STATE THIS EVENING. 12Z MODELS AND EVENING RUC SIMILIAR IN BEING A LITTLE SLOW WITH SYS TO OUR W. WL NOT CHANGE FCST FOR THE OVERNIGHT HOURS...AS SKIES WL RMN MOSTLY CLR. WL STILL HAVE A DESCENT RADIATIONAL NIGHT AS WK GRADIENT AND LIGHT BL WNDS WL ALLOW FOR DECOUPLING. OBS SHOWING TDS THIS EVENING IN THE MID/UPR 30S ALNG WITH CALM/LGT WNDS. WL CONT WITH TEMPS FALLING INTO THE UPR 30S FOR MOST AREAS. OTHERWISE NO CHANGES. .CAE...NONE. LCV sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 333 AM EST WED MAR 1 2000 CURRENTLY: LATEST FOG PRODUCT IMAGES AND SFC OBS INDICATING A FOG BANK EXPANDING ACROSS PORTIONS OF SE AL AND THE W FL PANHANDLE. AQQ ALSO 1/4 MI. WILL INCLUDE LOCALLY DENSE FOG WORDING TO AL AND PANHANDLE ZONES FOR THIS MORNING. ZFP/MODELS: MODELS HAVE INITIALIZED THE MIDWEST UPPER LOW AND TRAILING AXIS OF VORTICITY PRETTY WELL WITH ETA DOING THE BEST JOB BY A SMIDGE. SIMILAR AGREEMENT SEEN WITH CA TROUGH. ALL THREE MODELS STRING OUT THE MIDWEST VORT LOBE AND KEEP THE ENERGY TO OUR N PRIMARILY OVER THE TN VALLEY AS THE UPPER LOW MOVES NE AND IS ABSORBED INTO THE E CANADA TROUGH. AN UPPER RIDGE BUILDS ACROSS THE DIXIE STATES ON THU AS THE CA LOW CROSSES AZ/NM INTO THE TX/OK PANHANDLE AREA BY 48 HOURS. UNLIKE EARLIER RUNS...IT LOOKS AS IF THE SFC FRONT WILL MAKE IT THROUGH MOST IF NOT ALL OF THE CWFA...ALBEIT IN A MUCH WEAKENED STATE...LATE TONIGHT INTO THU. THE ETA...PREFERRED HERE...STALLS THE FRONT NEAR THE COAST ON THU WHILE THE NGM MOVES IT WELL DOWN THE PENINSULA WITH THE AVN A COMPROMISE. THE NGM AND AVN BOTH TRY TO SPIT OUT A FEW HUNDRETHS WITH THIS FROPA WHILE THE ETA IS DRY. BELIEVE MAIN IMPACT OF THIS FRONT LOCALLY WILL BE INCREASED CLOUD COVER AND SLIGHTLY COOLER TEMPS THAN PREVIOUSLY THOUGHT. WHILE AN ISOLATED SHOWER CANNOT BE RULED OUT...PREFER TO LEAVE OUT POPS FOR NOW. WITH NGM/AVN SHOWING FROPA PRIMARILY AT NIGHT OR DURING THE MORNING...LOW LEVEL INSTABILITY WILL NOT BE MAXIMIZED. WHILE ETA STALLS THE BOUNDARY... MOST OF THE INSTABILITY REMAINS OUT OVER THE WATER DURING THE DAYLIGHT HOURS AND SUBSTANTIAL CI MAY FURTHER LIMIT INSOLATION AND DESTABILIZATION OVER LAND. FAN PREDICTED TOO LARGE OF A DIURNAL RANGE FOR WED GOING TOO WARM ON THE MAXS AND TOO COOL WITH THE MINS ACROSS THE REGION. FWC MAX TEMPS WERE RIGHT ON THE MARK MOST AREAS WHILE A BLEND OF FWC/FAN MINIMA SCORED BEST. FAN NUMBERS HAVE COME DOWN A FEW DEGREES THIS PACKAGE AND ARE IN LINE WITH FWC WHICH ARE REASONABLE WITH EXPECTED CLOUDS AND FROPA. PLAN TO FOLLOW THESE GUIDANCE NUMBERS CLOSELY. MARINE: WINDS UNDER 10 KT MOST AREAS ATTM. EXCEPTION IS S 10 KT AT PNS S BUOY. ALSO...SEA BREEZE GAVE WAY ABRUPTLY TO LAND BREEZE BEFORE 11 PM LST NEAR SHORE APP BAY. RUC PICKS UP ON THIS AND WILL BE USED FOR FIRST PERIOD...E BECMG SW FOR NEAR SHORE E LEG AND S BECMG SW FOR W LEGS WITH SPEEDS 10 TO 15 KT. FOR TONIGHT...SW WINDS BECOME W. MAY NEED SCEC AS FRONT APPROACHES PER BL WIND FCST...BUT WILL STAY JUST BELOW FOR NOW. ON THU...WIND BECOMES NW AND DIMINISHES. FIRE WX: NO HIGHLIGHTS THROUGH THU. EXTENDED: THE AVN BRINGS THE S PLAINS LOW DUE E TO NW AL BY 00Z SAT WITH WARM FROPA FRI. I THINK WE/LL STAY IN THE STABLE AIR LONG ENOUGH TO AVOID POPS ON FRI PROPER...AND WILL CONTINUE TO HANG HAT ON FOLLOWING COLD FROPA FOR NEXT BEST CHANCE FOR RAIN. WILL INTRO CHANCE POPS W ZONES FRI NIGHT AND LEAVE IN FOR ALL ZONES ON SAT. SUN WILL BE DRIER AND ONLY SLIGHTLY COOLER BEHIND THE FRONT. PRELIM NUMBERS... TLH 79 52 76 47 0--0 PFN 71 57 72 54 0--0 DHN 75 53 73 48 --00 ABY 76 53 73 48 --00 VLD 78 53 73 47 0--0 .TLH... AL...NONE. GA...NONE. FL...NONE. WOOL fl AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1148 AM CST TUE FEB 29 2000 VIGOROUS UPPER SHORTWAVE MOVING THROUGH NORTHERN KS ATTM WITH SFC LOW TO THE W OF CNK. DRY SLOT AHEAD OF SFC LOW MOVING INTO EXTREME SE NEB. GOOD HEATING TAKING PLACE OVER CENTRAL AND ERN KS WITH TEMPS ALREADY IN THE MID 60S. DWPTS IN THE UPPER 40S TO NEAR 50 FEEDING NWD THROUGH ERN KS ATTM AND WILL BE PRIMARY LIMITING FACTOR FOR SVR TSTMS IN SE CORNER OF NE. 88DS SHOWING CONVECTION BECOMING MORE CELLULAR PAST HR WITH SOME INCREASE IN INTENSITY ALONG SOUTHERN FLANK OF PCPN AREA NEAR DRY SLOT...CLOSEST TO MOST UNSTABLE AIR. 15Z RUC INDICATES L.I.'S LOWERING TO -5 IN THE SE CORNER BY 21Z. THE ETA IS NOT AS UNSTABLE WITH L.I'S DOWN TO -2. ETA CAPES OF 300 J/KG PROGGED INT THE EXTREME SE DURG THE AFTN. HAVE JUST UPDATED SE CORNER ZONE GROUP TO REFLECT SOME SUNSHINE IN DRY SLOT. EXPECT CONVECTION TO EITHER REDEVELOP...OR MOVE BACK INTO THE AREA LATER THIS AFTERNOON AS BACK SIDE OF DRY SLOT ROTATES BACK INTO THE AREA. ELSEWHERE ACROSS THE CWA...SHRA AND A FEW TSRA LIKELY TO BE WIDESPREAD FROM S CNTRL INTO E CNTRL NE AND INTO WRN IA THROUGH LATE AFTN AS SHRTWV MOVES BY TO OUR S. NE NEB LIKELY TO ESCAPE BRUNT OF PCPN...BUT A FEW SHRA PSBL IN THE OFK AREA. FURTHER TO THE NW IT WILL MOST LIKELY REMAIN DRY. .OMA...NONE SKERRITT ne AREA FORECAST DISCUSSION...CORRECTED ADVISORY AREA NATIONAL WEATHER SERVICE NORMAN OK 1113 AM CST TUE FEB 29 2000 WIND ADVISORY WILL BE EXPANDED INTO N TX ZONES AND N CENTRAL AND CENTRAL OK FOR THIS AFTERNOON. MESONET INDICATES WIDESPREAD SUSTAINED SPEEDS IN 25-30MPH RANGE AND OCCASIONAL GUSTS OVER 40MPH IN THESE AREAS. LATEST RUC MAINTAINS STRONG GRADIENT INTO EARLY EVENING OVER N CENTRAL OK IN SW QUAD OF DEPARTING SURFACE LOW. UPDATED ZFP AND NPW WILL BE OUT SHORTLY. 24 .OUN... OK...WIND ADVISORY THIS AFTERNOON OKZ004>031-033>040-044-045 TX...WIND ADVISORY THIS AFTERNOON TXZ083>090 ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1113 AM CST TUE FEB 29 2000 WIND ADVISORY WILL BE EXPANDED INTO N CENTRAL AND CENTRAL OK FOR THIS AFTERNOON. MESONET INDICATES WIDESPREAD SUSTAINED SPEEDS IN 25-30MPH RANGE AND OCCASIONAL GUSTS OVER 40MPH IN THESE AREAS. LATEST RUC MAINTAINS STRONG GRADIENT INTO EARLY EVENING OVER N CENTRAL OK IN SW QUAD OF DEPARTING SURFACE LOW. UPDATED ZFP AND NPW WILL BE OUT SHORTLY. 24 .OUN... OK...WIND ADVISORY THIS AFTERNOON OKZ004>031-034-035-038 TX...NONE. ok AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 310 PM CST TUE FEB 29 2000 MAIN CONCERNS TONIGHT INCLUDE CLOUDS IN NORTHEAST...WINDS...AND MIN TEMPS. SFC LOW TO THE NE OVER ONTARIO PULLING OFF TO E-NE WHILE STRONGER SURFACE LOW TO THE SOUTH OVER KS BEGINNING TO ACCELERATE E-NE. OVER ABR CWA...WEAK HIGH PRESSURE STARTING TO BUILD IN ACROSS NW SD AND W ND. NW WINDS AROUND 20 MPH WITH A FEW GUSTS AROUND 30 MPH CONTINUE ACROSS NE AND N CNTL SD AND W CNTL MN THIS AFTN. SAT IMAGERY SHOWS AREA OF LOW CLOUDS PUSHING SLOWLY SE ACROSS NE 1/2 OF ND INTO BIG STONE & TRAVERSE COUNTIES IN MN. THIS AREA LINES UP WELL WITH THE MAXIMUM RUC 85H CAA AXIS...WHICH AS OF 20Z EXTENDED FROM NE MN TO NEAR HON IN SD. BASED ON THIS...SHORT TERM SAT TRENDS...AND LOW LEVEL RH PROGS...WHICH ARE FAIRLY SIMILAR AMONG THE MODELS...WILL INDICATE CLDY TO MSTLY CLDY SKIES TONIGHT NE AND TREND TOWARD MSTLY CLEAR W AND SW TONIGHT. WINDS SHOULD BEGIN TO ABATE THIS EVENING...BUT S/W DIVING SE OVER NORTHEAST ND AND N 1/2 OF MN COULD KEEP SFC PRSR GRADIENT A BIT TIGHTER OVER EASTERN COUNTIES SO WILL KEEP WINDS UP THROUGH MOST OF TONIGHT. FOR WED...N-S ORIENTED SFC RIDGE WILL SETTLE IN OVER CENTRAL DAKOTAS WHILE 5H RIDGE SHIFTS E OVER WESTERN DAKOTAS. ALONG WITH DRY AIR ALOFT...SHOULD SEE MSTLY SUNNY SKIES...W PSBL EXCEPTION OF FAR EASTERN SECTIONS DURING THE EARLY MORNING...WHERE LOW LEVEL RH/CLOUDS WILL GRADUALLY GIVE WAY TO DRIER AIR. FOR WED NIGHT AND THU...ANOTHER IN A SERIES OF UPPER LOWS WILL PULL OUT OF SOUTHWESTERN U.S. WHILE A WEAKER NORTHERN STREAM S/W APPROACHES FROM THE WEST. RH PROGS ALL SIMILAR IN INCREASING MOISTURE OVERNIGHT WED AND INTO THU. LIFT APPEARS WEAK HOWEVER...AS NORTHERN S/W ENERGY MOSTLY RUNS EASTWARD ALONG CAN BORDER/S. CAN ...AND STRONGER ENERGY WITH CUTOFF LOW TO THE SOUTH MOVES INTO S PLAINS THU AND CNTL PLAINS BY FRI. MODELS IN VERY GOOD AGREEMENT ON GENERAL TRENDS. NONE OF THE MODELS GENERATES ANY QPF OVER OR NEAR CWA THROUGH FCST PD...EXCEPT FOR AVN WHICH HINTS AT VERY LIGHT PRECIP POSSIBILITY TONIGHT WITH LOW LEVEL RH PASSING ACROSS FAR NE COUNTIES...AND HAVE DISCOUNTED THIS DUE MAINLY TO EXPECTED SUBSIDENCE. TEMPERATURES SOMEWHAT AT ODDS FOR LOWS TONIGHT...BUT WITH HIGHER DEW POINTS IN NORTHEAST...FAVORED WARMER FWC. ELSEWHERE...DIFFERENCES ARE SLIGHTER...AND GENERALLY WENT WITH A COMPROMISE OF FWC AND FAN. ...EXTENDED FORECAST DISCUSSION... THE EXTENDED MODELS ARE SIMILAR ON THE SYNOPTIC SCALE WITH THE SFC WEATHER PATTERN. THEY HAVE HIGH PRESSURE OVER EASTERN PART OF THE U.S. AND EASTERN PACIFIC OCEAN WITH A BROAD TROF OVER WESTERN HALF OF THE U.S. ON A SMALLER SCALE...THEIR ARE NO CONSISTENCIES. THEY EITHER PLACE A SFC LOW ALONG THIS TROF AS FAR SOUTH AS THE TEXAS PANHANDLE OR AS FAR NORTH AS SOUTHERN CANADA. ONLY THING ONE CAN GET OUT OF ALL THIS IS THAT WE HAVE LOW PRESSURE TO THE WEST OF THE CWA. AT THIS TIME...IT SEEMS THAT THE CURRENT FCST LOOKS GOOD FOR FRI AND SAT KEEPING IT DRY OVER THE CWA. ON SUNDAY...THE MRF BRINGS IN A WEAK SYSTEM TO GIVE A LITTLE PRECIP TO THE CWA. BUT THE MRF IS FASTER THAN THE ECMWF AND UKMET. THE ECMWF AND UKMET DELAYS THE SYSTEM UNTIL 12 TO 18 HRS LATER. THEREFORE...WILL CONTINUE THE DRY PATTERN THROUGH SUNDAY. ALL MODELS CONTINUE THE MILD TEMPS OVER THE CWA AND WILL USE THE FMR BUT WILL A LITTLE ADJUSTMENT. .ABR...NONE LORENS/SALMONS sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 909 PM EST TUE FEB 29 2000 HI PRESS RIDGE TO CREST OVER THE FA TONITE AS A CF MOVES ACRS THE WESTERN GREAT LKS REGION. THIS FRONT WILL HAVE A WAVE OF LOW PRESS RIDING NORTHWARD ALONG IT AS WELL. CF TO MOVE EAST ACRS THE EASTERN GREAT LKS REGION ON WED...WITH THAT WAVE MOVING ACRS SOUTHERN ONT. THIS SYS TO AFFECT THE ST LAW VLY BY LATE IN THE DAY ON WED. UNFORTUNATELY...NO 40KM RUC DATA AVAILABLE IN N-AWIPS...MOST LIKELY DUE TO Y2K LEAP YEAR GLITCH. WK H85 CAA ACRS THE FA EARLY TONITE TO BE REPLACED BY WK WAA BY 12Z WED. H85 MOISTURE NOT TO INCREASE ACRS THE WESTERN ZONES UNTIL AFTER 18Z WED. H85 TEMPS PLENTY WARM FOR ANY PCPN THAT FALLS TO BE RAIN THERE. 925 MB WET-BULB TEMPS WILL ALSO BE WARM ENUFF FOR RAIN IN NORTHERN NY BY LATER IN THE DAY. UPR-LVL RIDGE NOT TO CREST OVER THE REGION TIL AFTER 12Z WED. UPR- LVL DYNAMIX TO START TO AFFECT THE WESTERN ZONES BY AFTER 18Z WED. NOT TOO CONVINCED OF MEASURABLE PCPN HERE AT BTV BY 00Z...SO ADDED A CHC OF SPRINKLES BY EVENING TO THE CHAMP VLY FORECAST ON WED. IR SAT PIX SHOW HI CLDS MAKING SOME PROGRESS INTO THE ST LAW VLY ATTM. EXTRAPOLATION OF THICKER AREA OF CLDS ACRS THE GREAT LKS REGION ATTM HAS THEM MOVING INTO THE ST LAW VLY/NORTHERN ADIRONDACKS BY AROUND 06Z TONITE AND THROUGH THE CHAMP VLY BY AROUND 08-09Z. THESE CLDS SHOULD CONTINUE TO THIN AS THEY COME IN CONTACT WITH THE UPR RIDGE THOUGH. HAVE BUMPED UP A FEW OF THE LOW TEMP FORECASTS FOR TONITE BASED ON CURRENT DEW POINT READINGS. MOST OTHER CHANGES TO ZONES ARE PURELY COSMETIC. HYDRO-WISE...RIVER GAUGE READINGS INDICATE THAT ICE JAMMING IS MOST LIKELY STILL IN PROGRESS ATTM ALONG THE GREAT CHAZY...MISSISQUOI... CLYDE...AND WINOOSKI RIVERS...AS WELL AS ALONG THE BLACK RIVER (OF NORTHERN VT) AND ALONG SOME OF THE SMALLER TRIBUTARIES OF THE PASSUMPSIC RIVER. MOST OTHER MAJOR WATERWAYS ARE SHOWING SLOW FALLS OR NEARLY STEADY TRENDS. PW VALUES WITH NEXT FRONTAL SYS APPEAR TO BE 0.50-0.75". LATER SHIFTS MAY HAVE TO ADDRESS THE POTENTIAL FOR ANOTHER FFA DEPENDING ON HOW THE HSA RIVERS RESPOND DURING THE DAY ON WED. WORK ZONES ARE OUT. FINAL ZFP AFTER A QUICK LOOK AT THE LATEST LAMP DATA AND THE 02Z OBS. .BTV...NONE. MURRAY vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 908 PM EST TUE FEB 29 2000 SRN STREAM UPPER LOW LIFTING NEWD ACROSS MO...SOON TO GET SHUNTED EWD AS IT INTERACTS WITH THE NRN STREAM SHORT WV MOVG INTO NRN MN. THIS MATCHES UP WELL WITH THE 12Z MODELS. VERY THIN CI ATTM MOVG OVER THE SHORT WV RIDGE STILL OVER THE FA...BUT THE RUC SHOWS IT THICKENING UP IN NWRN SECTIONS OF THE FA LATE TONIGHT. SKY COND IN CURRENT ZONES LOOKS GOOD. TEMPS IN THE WEST ALSO LOOK GOOD...BUT WILL LOWER MINS SOME IN THE SOUTHEAST...WHICH WILL HAVE ANOTHER NIGHT OF GOOD RADIATIONAL COOLING CONDS. 00Z SOUNDINGS SHOW SOME LOW LEVEL GULFMEX RH FINALLY BEGINNING TO MOVE NEWD AHEAD OF THE SYSTEM. A FEW CELLS HAVE FIRED UP IN ARK AHEAD OF THE TRAILING COLD FNT. POPS MAY HAVE TO BE INCREASED FOR MORN SHRA IN THE NW CWA AND/OR ADDED A LITTLE FURTHER SOUTH. HOWEVER...THE RUC DOESN/T SHOW MUCH SRN DEVELOPMENT...AND WITH NO NEW DATA TO LOOK AT...WILL LET THE MID SHIFT HANDLE IT- SINCE ANY SHRA WOULD NOT REACH THE CWA IN THE TONIGHT PERIOD. VA...NONE. WV...NONE. NC...NONE. JJ va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 258 AM CST WED MAR 1 2000 FCST FOCUS TDY ON TEMPS AND CLOUDS. NGM AND RUC VERIFY BEST WITH CURRENT CONDS. HOLES SHWG UP IN CAA CLOUD DECK AS DRY AIR ABV 850 MXS DWN. MODELS ALL SHW DNWD MOTN AND VRY DRY ABV 850 MB. XPCT SOME SUNSHINE TDY. GUSTY NW WNDS XPCTD TO MIX DWN WITH DRIER AIR. TEMPS XPCTD TO HOLD NRLY STDY FM OVRNGT LOWS...OR MAYBE RISE A DEGREE OR TWO. MOS TEMPS APR RSNBL. RIDGE WL EDGE INTO ST TNGT. WNDS XPCTD TO STAY UP SO RAD SHLD NOT BE TO BAD THO SKIES WL CLR. MOS TEMPS APR TOO LOW IN VIEW OF TEMPS UPSTREAM IN DKTS/MN ATTM. SUNSHINE THUR WITH LGT WNDS. MOS TEMPS ON THE LOW SIDE. .UWNMS...VRY SIM TO OTHER MODELS. .MKX...NONE. 0...0...0...0 $$ MK wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 340 AM EST WED MAR 1 2000 MISFWA AVBL... UL ACRS NRN IL LIFTG NE AT 35KTS AND WL CONT A MORE NRLY TRACK AS IT CONTS TO WEAKEN AND LIFT INTO NRN STREAM TROF. SFC FNT FM NRN LK MI LOW TO ORD TO CGI TO BEGIN FASTER TRACK THRU FA THIS AM. CONVECTION AHEAD OF FNT SHOULD BE LIMITED TO SRN FA IN AREA OF STEEPER MIDLVL LAPSE RATES PER 06Z RUC SNDGS AND 60-70KT LLJ. ONLY ABOUT 30KTS MIXING DOWN IN HEAVIER SHRA/TSRA SO WND NOT MUCH OF CONCERN. AS SYS CONTS NNE WL LIMIT PCPN CHCS TO JUST LT AM. DRIER AIR WORKING DONW AND DVM SHOULD SEE SOME BREAKS ENTIRE FA LTR THIS AFT. PREFER SHORT-TERM DY1 ETA 925-850 MB TEMP DEPICTION SUPPORTED BY RUC AND WL CONT WITH FALLING TEMP WORDING AND IGNORE NGM DIURNAL RISE. TONIGHT CLEARING TREND CONTS AND DRY AMS NR FULL SUN ON DY2. WITH MID-UL SYSTEMS STILL PROGRESSIVE SHOULD KEEP PD OF COLD AIR BRIEF AND WITH FULL SUN HAVING SOME TROUBLE ACCEPTING DOWNWARD TREND OF DY2 HIGHS. FOR NOW WL CONT WITH CURRENT FCST. SRN STREAM CONTS PROGRESSIVE WITH STORM SYSTEMS QUESTION WL BE HOW FAST THE SYSTEM IN OK PANHANDLE AT F48 WEAKENS IN BUILDING HGHTS. FOR NOW WL CONT WITH PCPN CHCS FRI...LIQUID. .IWX...NONE MURPHY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1053 AM EST WED MAR 1 2000 AREA OF SHRA ALONG THE COLD FRONT IS NOW JUST E OF THE CWA...WITH ANOTHER AREA OF LIGHT PRECIP...MAINLY FROZEN...WORKING ITS WAY SE INTO UPR MI. DRIVING FORCE BEHIND THIS SECOND AREA OF PRECIP IS A FAIRLY VIGOROUS SHORT WAVE DROPPING SE OUT OF CANADA...WITH SOME LAKE ENHANCEMENT AS GOOD CAA IS TAKING PLACE BEHIND THE COLD FRONT. LATEST RUC MATCHES UP WELL WITH 00Z ETA...BOTH SEEM TO BE PANNING OUT WELL WITH RESPECT TO AMOUNT AND TIMING OF CAA. RAPID DRYING AT MID LEVELS BEHIND THE FRONT WILL CONTINUE TO BE A LIMITING FACTOR FOR POST FRONTAL PRECIP THIS AFTERNOON. WILL KEEP SCT POPS IN THE AFTERNOON FORECAST...BUT WILL HAVE TO MENTION SOME MIX OF RAIN ESPECIALLY EARLY ACROSS MOST OF NRN LOWER MI. ERN UPR HAS COOLED ENOUGH FOR PRECIP TO BE ALL SNOW FOR THE REST OF THE DAY. WILL ALSO HAVE TO FRESHEN WORDING OF TEMP AND WIND FORECAST. .APX...NONE. EME mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 1001 AM EST WED MAR 1 2000 BAND OF SHOWERS JUST AT THE EASTERN EDGE OF THE CWA. HOWEVER...COLD FRONT STILL BACK ACROSS WESTERN OHIO...TO A SDF-BWG-TUP LINE. OVER THE LAST HOUR THERE HAVE BEEN A FEW SHOWERS/SPRINKLES THAT DEVELOPED ALONG IT IN KY. BOTH THE RUC AND 06Z ETA DIDN/T INDICATE ANY RAIN FOR THE CWA...INCLUDING THE PAST BAND. WITH THE SHOWERS IN NE OF BWG ATTM...WILL KEEP A SMALL POP IN FOR SW VA AND NE TN... BUT DROP THE POPS FOR THE REST OF THE CWA AS THE 12Z BNA SOUNDING INDICATED VERY LITTLE INSTABILITY WHEN MODIFIED FOR 70 OVER 52. BOTH MODELS DO HOWEVER...INDICATE THE GOOD DEEP MOISTURE UP TO 500 MB WILL BE EXITING THIS MORNING...LEAVING JUST 80H MOISTURE. THIS HAS DEVELOPED INTO SC ACROSS CENTRAL KY AND MIDDLE TN AHEAD OF THE FRONT. MAY HAVE TO HIT A LITTLE HARDER ON CLOUD COVER. ALSO WITH MORE CLOUDS MAY HAVE TO BROADEN THE TEMP RANGE DOWNWARD...GIVEN 15Z OBS AND LAMP TEMPS. WILL WAIT FOR THE CURRENT BAND OF SHOWERS TO EXIT BEFORE THE UPDATE. WILL CONTINUE WITH THE 15 TO 25 AND GUSTY WORDING IN THE HIGHER ELEVATIONS. 12Z BNA SOUNDING AND MRX VWP CONTINUE TO SHOW ABOUT 30 TO 40 KTS AT 3K TO 5K FEET...AND EXPECT SOME OF THESE WINDS TO MIX DOWN THIS AFTERNOON. .MRX... NC...NONE. TN...NONE. VA...NONE. RBP tn NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 210 PM MST WED MAR 1 2000 SHORT TERM DISCUSSION: UPPER LEVEL LOW TRACK CRITICAL TO FORECAST LATE TONIGHT AND ESPECIALLY TOMORROW. WATER VAPOR SHOWS UPPER LOW DRIFTING EAST/SOUTHEAST AND EXPECT THIS TRACK TO CONTINUE THROUGH MOST OF THE NIGHT UNTIL JET MAX BEGINS TO MOVE THRU TROF BOTTOM AROUND 12Z. 18Z RUC LOOKS TOO FAR NORTH...ESPECIALLY CONSIDERING FLOW ON AZTEC NEW MEXICO PROFILER SHOWING WINDS BELOW 600 MB BACKING TO THE EAST. THIS SUPPORTS MID LEVEL CIRCULATION CENTER TRACKING SOUTH OF AZTEC...AND THUS MORE IN LINE WITH 12Z AND 18Z ETA RUNS. WITH THIS TRACK...PRESSURE FALL CENTER EXPECTED OVER EAST CENTRAL NEW MEXICO. THUS LOW LEVEL FLOW WILL BECOME MORE EASTERLY AND KEEP DEEPER MOISTURE OUT OF CWA UNTIL AFTER 12Z WHEN WE WILL HAVE TO RELY ON WRAP AROUND EFFECT. ALREADY BACKED OFF A TAD ON POPS WITH MORNING UPDATE...BUT WILL KEEP THE "BECOMING LIKELY TOWARD DAYBREAK" ALONG THE FRONT RANGE WHERE ENOUGH UPSLOPE AND 700-300 UPWARD Q-G FORCING TO AID PRECIP DEVELOPMENT IN MOIST ADIABATIC LAPSE RATES. RAIN/SNOW MIX EXPECTED WITH WET BULB ZERO READINGS OF 6000-6500 FEET. BARJENBRUCH LONG TERM DISCUSSION: APRCHG UPR LO CONTS TO MOV SOUTH OF EAST ACRS NWRN AZ EARLY THIS AFTN THO MAY BE STARTING TO TURN MORE TO THE E. THIS WILL BE OUR THIRD ATTEMPT AT PCPN IN DEN FROM ONE OF THESE IN LESS THAN A WEEK...AND THIS PROGRESSION OF STORM SYSTEMS WILL CONT THRU THE LONG RANGE PERIOD (5 DAY FCST) AND BEYOND. FIRST TWO ATTEMPTS RESULTED IN DRY WX HERE AND SOME PCPN ON THE PLAINS...TRACK OF UPCOMING SYSTEM IS SIMILAR BUT THERE ARE SOME SIG DIFFERENCES THAT SHOULD GIVE A BETTER CHC OF PCPN FOR NERN CO. STILL...YSTDY APPEARED THAT THE BRUNT OF THE STORM FOR THU WUD PASS JUST S OF OUR CWA AND TODAY'S MODELS CONT TO SHOW THIS TREND WITH A SIG PCPN EVENT LIKELY TO OUR S...SO THE BIG QSTN FOR HERE IS HOW MUCH PCPN...LIKELY TO FALL AS SNOW HERE...WILL BE THIS FAR NORTH. ALL MODELS START OUT VERY CLOSE EXCEPT FOR A BIT STRONGER WIND ANALYZED IN THE ETA AT 300 MB. WITH THIS JET STILL ON THE BACKSIDE THE SYSTEM HAS CONTINUED TO DIG...BUT OVERNIGHT THIS JET WILL BE ROTATING AROUND THE SYSTEM AND DURING THE DAY THU THE UPPER LOW WILL THEN MOVE MORE ENE. ALL MODELS SHARE THIS SCENARIO AND HAVE SIMILAR SPEED OF THE SYSTEM BUT ARE DIFFERENT IN HOW CLOSE THE UPR LO COMES TO CO WITH THE ETA CONTINUING TO BE THE FURTHEST S AND THE NGM FURTHEST N. NOT SURE WHY THE ETA IS ALSO WEAKER THEN THE OTHER TWO...BUT COMBINED WITH ITS FURTHER S PSTN THIS RESULTS IN MUCH SHALLOWER UPSLOPE FOR NERN CO ALONG WITH LESS FORCING AND CONSEQUENTLY LESS PCPN THEN THE OTHER MODELS. YSTDYS PMD DISC POINTED OUT TENDENCY FOR THESE LOWS TO BE SOMEWHAT DEEPER THAN MODEL PREDICTIONS WCH WUD FAVOR NGM OR AVN STRENGTH OF THE SYSTEM. AS FOR PSTN...DO NOT HAVE A GOOD FEEL ON THIS ONE WITH NOTHING IN CRNT DATA TO ARGUE EITHER WAY. EITHER WAY THO IT WUD TAKE A MORE NRN SHIFT TO PUT NERN CO IN AS GOOD AN AREA FOR HVY PCPN AS FARTHER S...WHILE A SHIFT FARTHER S OF COURSE MIGHT MEAN NO PCPN FOR AT LEAST AREAS N OF I-76. RIGHT NOW FAVORING PCPN IS THAT THIS IS A LARGER SCALE SYSTEM THAN THE LAST MORE COMPACT ONE...ITS NOT QUITE AS BONE DRY ATTM...AND SCREAMING SLY FLOW NOW IN PLACE NEAR THE KS BDR S TO TX WILL BRING MSTR N TO BE WRAPPED AROUND AT LEAST SOMEWHAT FOR THU. THERE SHUD BE DEEP UPSLOPE...DISCOUNTING ETA AS TOO WEAK AND A BIT TOO FAR S...ALTHO NOT TERRIBLY STRONG AND WITH BEST DYNAMICS TO THE S. THIS GIVES THE SCENARIO FOR TOMORROW OF TWO BEST AREAS FOR THE MOST PCPN...ONE CLOSER TO THE FOOTHILLS WITH THE UPSLOPE AND THE OTHER ZNS 41..46..47..AND PSBLY 49. WITH DEEP UPSLOPE SHD COOL ENUF FOR SNOW IN ZONES NEAR THE FTHLS AND ELEVATION IN ZNS 46 AND 47 SHD BE GOOD ENUF FOR SNOW...BUT RAIN CUD BE A FACTOR FOR SOME ERN ZNS WCH WUD AGREE WITH WHAT GLD IS DOING IN ZNS 90..91 AND 92. CONTS TO BE A LOT OF UNCERTAINTY WITH THIS SYSTEM...CUD STILL RESULT IN HOISTING FOR SOME AREAS WHILE ON THE OTHER HAND MOST PCPN CUD STAY TO OUR S. WILL TAKE A MIDDLE ROAD FOR NOW. IN THE MTNS NEVER ANY GUD OROGRAPHIC FLOW WITH BEST SNOWS PROB IN FTHL ZN 36 BUT ATTM WILL KEEP BELOW ADVY CRIT. IN THE LONGER TERM THE PARADE OF SYSTEMS CONTINUES WITH A ONE TO TWO DAY BREAK BETWEEN SYSTEMS. SOME DISAGREEMENT WITH TIMING FOR THE NEXT ONE WITH THE MRF/UK AND CANADIAN BRINGING A WEAKISH SYSTEM NEAR AREA ON SAT WHILE EC AND NOGAPS ARE SLOWER AND WUD HAVE ANY CHC OF PCPN WAITING TIL SUN. PREV SHIFT TOOK OUT CHC OF SHWRS FOR SUN SO WILL KEEP THIS FCST ATTM. CANADIAN MODEL IS FARTHEST S ON SAT AND DRIEST WHILE MRF FARTHEST N WITH BEST CHC OF RAIN OR SNOW SHOWERS EVEN ON THE PLAINS...SLGHT CHC PUT IN YSTDY STILL LUKS REASONABLE. ASSUMING THIS TIMING...MILD BETWEEN SYSTEMS FOR SUN INTO MON. THEN TIMING FOR NEXT SYSTEM ON TUE AND THIS ONE LUKS INTRIGUING FOR GUD SNOW POTENTIAL ON THE PLAINS...BUT THAT IS TOMORROWS FCST PROBLEM. SZOKE .DEN...NONE. co SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO 200 PM MST WED MAR 1 2000 ...MAIN FORECAST PROBLEM IS PRECIPITATION AMOUNT WITH THURSDAY STORM ALONG WITH PRECIPITATION TYPE ON THE SOUTHEAST PLAINS... CUTOFF LOW SPINNING OVER NORTHWEST ARIZONA THIS AFTERNOON. IR IMAGERY SHOWING ENHANCEMENT OF CLOUDS OVER NORTHWEST NEW MEXICO IN APPARENT DIFFLUENT REGION AHEAD OF THE CUTOFF. THE MAIN CHALLENGE TO THE FORECAST IS THE EXACT TRACK OF THE CUTOFF AND ASSOCIATED SURFACE CYCLONE. ALL THE MODELS SHOW A GENERAL CONTINUED EASTWARD PROGRESSION OF THE CUTOFF LOW. NGM IS FURTHER NORTH AND IS DISCOUNTED. THE AVN AND ETA HAVE SIMILAR TRACKS WITH THE ETA BEING SLIGHTLY FURTHER SOUTH. WITH BLOSSOMING CLOUD FIELD IN NEW MEXICO AND SOUTHERLY FLOW AHEAD OF LOW AND DEEP SOUTHERLY FLOW...SNOW ADVISORY CRITERIA SHOULD BE MET IN ZONE 61 TONIGHT AND I WILL CONTINUE THE ADVISORY. ON THURSDAY... A SURFACE LOW GETS CRANKED UP OVER NORTHEAST NEW MEXICO AND IT MOVES INTO THE TX/OK PANHANDLE DURING THE DAY. DEEP EAST TO NORTHEAST FLOW DEVELOPS OVER THE PLAINS AND ADJOINING MOUNTAINS. ETA SHOWS 15 TO 30 KNOTS OF NORTHEAST UPSLOPE DURING THE DAY IN THE LAYER UP TO 700 MB. WITH AMPLE MOISTURE AND LIFT...ZONES 65...66 AND 70 SHOULD HAVE NO PROBLEM REACHING WARNING CRITERIA ON THURSDAY. THE HEAVY SNOW SHOULD END BY LATE AFTERNOON. THE ADJOINING PLAINS IN ZONES 74 AND 75 SHOULD ALSO HAVE NO PROBLEMS REACHING WARNING CRITERIA. THE TRICKIER FORECAST IS FURTHER NORTH. RAMPART RANGE ZONE IS ON THE NORTHERN EDGE OF THE SIGNIFICANT MOISTURE AND NORTHEAST UPSLOPE FLOW. THE SLIGHTLY FURTHER NORTH SOLUTION OF THE AVN WOULD GIVE THIS ZONE WARNING CRITERIA WHILE THE FURTHER SOUTH ETA WOULD GIVE AMOUNTS MORE IN LINE WITH AN ADVISORY. GIVEN THE UNCERTAINTY IN THE FORECAST TRACK...I WILL ERROR ON THE CAUTIOUS SIDE AND ISSUE A WARNING FOR ZONE 67. LATEST RUC SUPPORTS THE AVN SOLUTION MORE THAN ETA...BUT AT 06Z TONIGHT THE DIFFERENCES IN POSITION ARE MINOR. THERE IS A SIMILAR SITUATION FOR ZONE 72 AS WHETHER OR NOT TO GO WITH AN ADVISORY. GIVEN THIS IS A MAJOR INTERSTATE ROUTE...I WILL BE A LITTLE CAUTIOUS AND GO WITH AN ADVISORY. AS THE LOW CONTINUES TO DEVELOP ON THURSDAY...ABUNDANT MOISTURE GETS WRAPPED BACK INTO THE SYSTEM. THE AVN AND ETA SHOULD HAVE SOME TYPE OF DEFORMATION BAND DEVELOPING ON THE EASTERN PLAINS DURING THE DAY. TEMPERATURES ON THE PLAINS WILL INITIALLY BE TOO WARM FOR SNOW. HOWEVER...THE ETA AND AVN HAVE STRONG RISING MOTION IN THE BAND WITH SIGNIFICANT DIABATIC COOLING. 700MB TEMPERATURES ARE PROGGED TO FALL TO -5 TO -7C IN THIS BAND. WITH EVAPORATIVE COOLING AND COOLING DUE TO MELTING...SNOW LEVEL MAY REACH DOWN TO THE PLAINS IN THE BAND OF HEAVIER PRECIPITATION. AWAY FROM THE BAND OF HEAVIER PRECIPITATION...ONLY RAIN OR WET SNOW WILL FALL. I'LL ISSUE A WATCH FOR THURSDAY AND THURSDAY EVENING FOR ZONES 76 TO 81 ON THE PLAINS AS THE EXACT LOCATION AND STRENGTH OF THE BAND IS UNCERTAIN. THIS REASONING ALSO AGREES WITH KGLD AND KDDC. AVN AND ESPECIALLY ETA SUGGEST SIGNIFICANT PRECIPITATION IN A BAND WITH THE ETA GIVING AROUND 1 INCH OF LIQUID FOR THE SOUTHEAST CORNER OF THE PLAINS. HEAVY PRECIPITATION SHOULD MOVE OUT OF THE PLAINS BY MIDNIGHT. THE FINAL PROBLEM AREAS ARE ZONES 71 AND 73 WHICH HAVE THE HIGHEST POPULATION CONCENTRATIONS. ZONE 73 IS A PRECIPITATION HOLE AND IS DOWNSLOPE FOR NORTHEAST FLOW. ZONE 71 IS ALSO DOWNSLOPE FOR NORTHEAST FLOW AS WELL. I DO NOT THINK THE DEFORMATION BAND WILL MAKE IT THAT FAR WEST DURING THE AFTERNOON...AND PRECIPITATION MAY STAY AS RAIN OR WET ZONE IN THESE ZONES. AS A RESULT...I WILL NOT ISSUE ANY HIGHLIGHTS AT THIS TIME. EVENING SHIFT WILL HAVE TO MONITOR ANY CHANGES IN THE PATH AND STRENGTH OF THE SYSTEM FOR ANY CHANGES. ON FRIDAY...SYSTEM MOVES EAST WITH A GENERALLY NICE DAY IN STORE. IN THE EXTENDED...MRF AND OTHER LONG RANGE MODELS HAVE ANOTHER SYSTEM IS PROGGED TO MOVE NORTHEAST OVER THE STATE ON SATURDAY. HOWEVER... LATEST AVN HAS THE CUT OFF LOW REMAINING FURTHER WEST OVER ARIZONA. FOR NOW...I WILL GO ALONG WITH MRF AND OTHER LONG RANGE MODELS. ALL THE MODELS DO NOT INDICATE ANY SURFACE CYCLONE DEVELOPMENT TO OUR SOUTH OR EAST ON SATURDAY. CHANCE OF SNOW MOUNTAINS AND CHANCE SHOWERS PLAINS LOOK REASONABLE. SATURDAY MAY BE DRIER IF AVN VERIFIES. THE UKMET SUGGESTS TROUGH WILL BE A LITTLE SLOWER SO WILL LEAVE SOME SHOWERS FOR EARLY ON SUNDAY ON THE PLAINS AND PARTS OF THE MOUNTAINS. MONDAY WILL BE DRY EXCEPT TO SOUTHWEST MOUNTAINS WHERE SOUTHERLY FLOW AHEAD OF NEXT PESKY CUTOFF MAY BRING SOME SNOW. .PUB...COZ061(SAN JUAN MOUNTAINS)...SNOW ADVISORY TONIGHT. COZ065>067..070(SOUTHEAST MOUNTAINS)...WINTER STORM WARNING LATE TONIGHT AND THURSDAY. COZ072 (NORTHERN EL PASO COUNTY)...SNOW ADVISORY LATE TONIGHT AND THURSDAY. COZ076>081 (SE PLAINS)...WINTER STORM WATCH THURSDAY AND THURSDAY EVENING. WOLYN co AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LUBBOCK TX 1230 PM CST WED MAR 1 2000 UPDATED FIRST PERIOD ZONES TO INCREASE WINDS TO CAUTION (15-25 MPH) OVER THE WESTERN 2/3 OF THE AREA. SURFACE LOW PRESSURE IS STILL ORGANIZING OVER SOUTHERN NEW MEXICO. FAIRLY TIGHT GRADIENT BETWEEN THIS AREA OF LOWER PRESSURE AND RIDGE AXIS FROM NORTHEASTERN OK INTO EAST TEXAS. THIS GRADIENT HAS RESULTED IN IMPRESSIVE SURGE OF MOISTURE THROUGH FORT STOCKTON WITH DEWPOINTS IN THE 50S EARLIER...BEFORE MIXING LOWERED THEM SOMEWHAT. MOISTURE IS TRAVELING THE PECOS RIVER ROUTE BUT WILL CONTINUE TO INCREASE THROUGHOUT THE REMAINDER OF THE AFTERNOON AND EVENING...PERHAPS AHEAD OF SCHEDULE. 15Z RUC2 HAS PRECIP OVER SOUTHWESTERN SOUTH PLAINS AROUND 9 PM. .LBB...NONE. JAMES tx