EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 930 AM EDT SUN APR 11 1999 CURRENTLY...LIGHTER SURFACE FLOW STARTING OFF THE DAY COMPARED TO YESTERDAY AND THERE WAS MORE STRATUS/FOG. MORNING SOUNDINGS CONTINUE VERY DRY ABOVE THE SHALLOW MOIST LAYER. TODAY...ONCE CONVECTIVE HEATING/MIXING GETS STARTED THE STRATUS WILL DISSIPATE QUICKLY AND IT WILL BE A SUNNY AFTERNOON. ONLY QUESTIONS IN THE FORECAST ARE MINOR...WILL GRADIENT PICK UP LIKE THE NGM INDICATES AND HOLD OFF SEA BREEZE OR WILL THE LATEST RUC WIN OUT...AND WHO WILL GET THE RECORD HIGHS TODAY. OVERALL...THERE IS NOTHING THAT REALLY NEEDS UPDATING AND CURRENT FORECAST WILL HOLD. MARINE...SURFACE HIGH OVER SOUTH FLORIDA BUT WINDS OFFSHORE ARE QUITE VARIABLE. THE WINDS WILL BECOME SOUTHWEST IN ADVANCE OF FRONT MOVING INTO THE SOUTHEAST STATES. CURRENT FORECAST OF 10 KNOTS SHOULD BE OKAY AS MAIN INCREASE IN GRADIENT LIKELY TO BE LATE TODAY. TODAY...MLB...NONE. PENDERGRAST/LASCODY NNNN fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 145 PM CDT SUN APR 11 1999 FOCUS WILL BE ON SKY/TEMPS TODAY. AVN/ETA AND NGM ALL VIRTUALLY ON SAME PAGE TODAY WITH ONLY THE USUAL MINOR MODEL DIFFERENCES SHOWING UP. HIGH PRESSURE SHOULD BUILD IN FROM THE NORTHWEST TONIGHT THRU TUESDAY AS LOW PULLS EAST. WILL HAVE TO CONTEND WITH WRAP-AROUND MOISTURE NEXT 36 HRS IN SOME AREAS. MODEL CROSS SECTIONS SUGGEST MOISTURE LINGERING AOB H85 THRU TUESDAY MORNING IN NORTH HALF. ACCORDING TO 1000-850 MOISTURE PANELS...THE ETA HAS ITS NORMAL BIAS OF TOO MUCH LOW LEVEL MOISTURE...WHILE NGM APPEARS TOO DRY. USING SAME OFF 15Z RUC...SOUTHERN EDGE OF CLOUDS APPEARED TO LINE UP WITH 60 PCT RH CONTOUR. THIS LINE MOVES ONLY SLOWLY SOUTHEAST THRU 12 HOURS. WILL CONSTRUCT ZONES ROUGHLY BASED ON 18Z RUC MOISTURE FIELD THIS EVENING THEN A BLEND OF NGM/ETA THEREAFTER. IN SOUTHERN AREAS DEVOID OF SC FIELD THERE WILL LIKELY BE DIURNAL CU FORMATION MONDAY ACCORDING TO CU RULES SO GOING FORECAST OF PARTLY SUNNY W KY / MOSTLY SUNNY SEMO LOOKS GOOD. WINDS SHOULD SUBSIDE TO 10 KT OR LESS TONIGHT AS GRADIENT RELAXES BUT NOT ENOUGH TO PREVENT A 10 TO 15 MPH NORTHWEST WIND MONDAY. EXPECT A DROPOFF TO L/V MONDAY NIGHT AS HIGH CENTER PASSES OVERHEAD. THIS COULD SET UP A GOOD RADIATIONAL COOLING NIGHT...IE FROST... HOWEVER MODELS AGREE THAT APPROACHING MID-HIGH LEVEL MOISTURE AHEAD OF PACIFIC SYSTEM MAY PUT A CRIMP ON COOLING POTENTIAL. BASED ON CURRENT GUIDANCE NUMBERS WOULD BE PATCHY LIGHT FROST IF OCCURS. FWC AND FAN TEMPS NOT LINING UP WELL THRU MONDAY. NGM DID NOT INITIALIZE H85 TEMPS VERY WELL THIS MORNING...SO THINK FWC LOWS ARE TOO WARM IN AREAS THAT DO NOT HAVE CLOUDS. IN AREAS WHERE CLOUDS MOVE IN THE SLIGHTLY WARMER FWC NUMBERS MAY BE BEST. ON MONDAY-TUESDAY PLAN TO TAKE A BLEND BETWEEN FAN AND FWC. .PAH...NONE. SDB NNNN ky AREA FORECAST DISCUSSION FOR EASTERN UPPER/NORTHERN LOWER MI NATIONAL WEATHER SERVICE GAYLORD MI 643 PM EDT SUN APR 11 1999 HAVE SENT OUT AN UPDATE TO A PORTION OF NRN LWR MI TO UP THE SNOW AMOUNTS - WHICH FOR A FEW COUNTIES WILL RESULT IN WIDESPREAD TOTAL ACCUMS OVER 6 INCHES. HAVE THUS UPGRADED SNOW ADVISORY TO WINTER STORM WARNING FOR OGEMAW AND ROSCOMMON COUNTIES. UPR LOW NOW OVER SE LOWER MI WITH COLD-CONVEYOR BELT HIGHER CLOUD TOPS/ENHANCEMENT NOTED ON SATELLITE IR ACROSS NRN LWR MI AT THIS TIME. WIDESPREAD 20-25 DBZ'S CURRENTLY NOTED OFF OF THE DOPPLER RADAR ACROSS THE WARNED COUNTIES...WITH SCATTERED AREAS UP TO 35 DBZ IN OGEMAW COUNTY NORTH OF WEST BRANCH (WHICH WOULD EQUATE TO AROUND 2" PER HOUR). THUNDERSNOW AND HEAVY SNOWFALL RATES EARLIER IN THE DAY SOUTH OF M-72 REALLY OFFSET THE HIGH SUN ANGLE/"TIME OF YEAR" FACTOR AND ALLOWED FOR SIGNIFICANT ACCUMULATIONS ON ROADWAYS. CONCERN GOING INTO EVENING HOURS IS DIMINISHING SOLAR INSULATION...WHICH WOULD MAKE IT EASIER FOR SNOW TO ACCUMULATE ON PAVEMENT EVEN W/O HEAVY SNOWFALL RATES. STILL EXPECT TO SEE A RAPID DIMINISHMENT IN THE ACTIVITY BY 8-10 PM AS PER LATEST RUC DATA. .APX...WINTER STORM WARNING...THIS EVENING...MIZ034-035. SNOW ADVISORY...THIS EVENING...MIZ020-026>029-032-033-036- ...CORRECTED TO ADD ADDITIVE DATA... HURLEY NNNN mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1120 AM EDT SUN APR 11 1999 WEAKENING UPPER LOW TO CROSS THE AREA THIS MORNING. STILL...HAD SOME HEAVIER PRECIPITATION AND THUNDERSTORMS ACROSS MY NORTHEAST COUNTIES. SOME PRECIPITATION IN THE FORM OF SLEET AND SNOW TO MY NORTHEAST WITH LOCAL LIGHT ACCUMULATIONS REPORTED. COOL CLOUD TOPS LIFTING TO THE NORTHEAST AND RADAR TRENDS SUGGEST BULK OF HEAVIER QPF WILL EXIT THE AREA BY NOON. STILL EXPECT ON AN OFF LIGHT PRECIPITATION THROUGH THE DAY...FOR MY NORTHERN COUNTIES. WILL GO WITH MORE SNOW AND SLEET AND IN THESE COUNTIES AS RUC THICKNESS PLOT SHOWS VALUES DROPPING THROUGH THE DAY. WILL MENTION LOCAL ACCUMULATIONS OF AN INCH OR TWO. FURTHER SOUTH FOR I96 AND I94 REGIONS...ALOT OF CLOUDS AND TEMPERATURES WILL STRUGGLE...ESPECIALLY AS WINDS WILL SHIFT TO THE NORTH. WILL BUMP TEMPERATURES DOWNWARD. WILL MAINTAIN CURRENT SHOWER WORDING. ZONES WILL BE ISSUED BY 1530Z. GRR...NONE. MJS NNNN mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 435 AM EDT SUN APR 11 1999 IR/WV IMAGERY LOOP INDICATING H5 CUTOFF CIRCULATION AND ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER NORTH CENTRAL IOWA ATTM. MODEL FORECASTS REMAIN SIMILAR IN ADVANCING CUTOFF EASTWARD AND GRADUALLY WEAKENING IT AS IT ENCOUNTERS RIDGE OVER THE EASTERN GREAT LAKES. MODEL DIFFERENCES ARE FOUND IN THE POSITIONING OF THE SURFACE LOW AS IT TRACKS EAST WITH THE AVN CONTINUING TO BE FURTHEST SOUTH. THE ETA THIS MODEL RUN HAS COME MORE IN LINE WITH THE VERY CONSISTENT MODEL RUN TO RUN PERFORMANCE OF THE NGM. THE (00Z,03Z) RUC MODEL RUN IS CONFIRMING THE 00Z LONG RANGE MODELS WITH BEING CONSISTENT IN TAKING THE SURFACE LOW FROM NORTH CENTRAL IOWA ALONG THE MICH/IND BORDER TO NORTHEAST OHIO BY LATE IN THE DAY. THIS TRACK SEEMS QUIET ACCEPTABLE BASED ON MSAS ISALLOBARIC ANALYSIS AND WARM FRONTAL BOUNDARY POSITION. H5 CUTOFF HAS HAD A HISTORY OF CONVECTION MOST LIKELY IN RESPONSE TO STRONG UVM ACTING UPON STEEP LAPSE RATES. AS THIS AREA OF UVM MOVED NORTHEAST THROUGH THE UPPER PENINSULA AND INTO ONTARIO CONVECTION BEGAN TO DECREASE THROUGH THE UPPER MIDWEST. AS THE CUTOFF MOVES EAST A SECOND AREA OF UVM WILL MOVE ACROSS MUCH OF SOUTHERN LOWER MICHIGAN THIS MORNING. AGREE WITH SPC'S OUTLINE FOR GENERAL CONVECTION TAKING IT ON A LINE FROM MANISTEE TO ACROSS ARENAC AND GLADWIN COUNTIES...HOWEVER WILL HOLD OFF ENTIONING THUNDER FOR THESE ZONES. MAIN FORECAST PROBLEM WILL BE TO ADDRESS THE EVAPORATIONAL AND DYNAMICAL COOLING PROCESS AND WHAT AFFECT IT WILL HAVE ON THE CWA TODAY. PRECIPITATION MAKING STEADY PROGRESS TO THE NORTHEAST BASED ON AREA 88D COMPOSITE. AS IT MOVES NORTHEAST IT WILL ENCOUNTER VERY DRY AIR TO THE NORTH. AS THE ATMOSPHERE MOISTENS UP SURFACE TEMPS WILL LOWER OR REMAIN NEARLY STEADY IN THE LOWER TO MID 30S TODAY. AS A RESULT OF STEEPENING LAPSE RATES AND DYNAMIC COOLING...RAIN AT THE ONSET IN MOST LOCATIONS WILL CHANGEOVER TO SNOW WHICH WILL ACCUMULATE MAINLY ON THE GRASSY AREAS. WITH A STRONG LOW LEVEL EAST FLOW...ABUNDANT MOISTURE TRANSPORT WILL FEED INTO THE OROGRAPHIC FAVORED AREA OF INTERIOR NORTH CENTRAL LOWER...THUS HAVE ISSUED A WINTER WEATHER ADVISORY FOR ANTRIM...OTSEGO...MONTMORENCY... KALKASKA...CRAWFORD AND OSCODA COUNTIES FOR TODAY. TEMPERATURES SHOULD BECOME NEARLY STEADY AFTER ONSET OF PRECIPITATION THUS HAVE HAD TO ADJUST MAXES TO CURRENT CONDITIONS. COOL NORTHEAST FLOW TO CONTINUE TONIGHT AND MONDAY RESULTING IN ACCEPTANCE OF FWC/FAN GUIDANCE. .APX...WINTER WEATHER ADVISORY TODAY..ZNS 21>23..27>29. FITZSIMMONS NNNN mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 330 AM CDT SUN APR 11 1999 SNOW/RAIN MIXTURE CONTINUING OVER ERN MN...W CENTRAL WI. LATEST RUC MODEL HAS MOSTLY ISENTROPIC ASCENT ENDING BY 12Z. SOME LIFT REMAINS IN EXTREME NERN PORTION OF FORECAST AREA...SO WILL KEEP MENTION OF SNOW GOING THERE. ENOUGH LOW LEVEL MOISTURE REMAINS...AS WELL AS CYCLONIC SHEAR TO KEEP SHOWERS GOING MOST AREAS TODAY. ALL MODELS ROTATE CYCLONIC SHEAR AXIS...ASSOCIATED WITH EXITING UPPER LOW... OVER NRN/E CENTRAL MN. MODELS INDICATE CONTINUED Q DIVERGENCE WITH THIS FEATURE. ENOUGH LOW LEVEL MOISTURE REMAINS FROM CLOUDINESS TONIGHT...SOME DRYING FROM NORTHEAST AND DYNAMIC COOLING SHOWING UP IN 850 MB TEMPERATURES...BUT BELIEVE MODELS ARE A LITTLE COLD ON TONIGHT'S LOWS. COOL AIR MASS WITH SURFACE HIGH ON MONDAY...BUT ENOUGH SUN FOR A WARMER TEMPERATURES. LATEST AVN MODEL INDICATES POTENTIAL FOR THUNDERSTORMS TUESDAY NIGHT/WEDNESDAY MORNING WITH STRONG THETA-E RIDGE/THICKNESS DIFLUENCE. WILL BACK OFF ON MENTION OF THUNDERSTORMS TUESDAY EXCEPT FOR WRN ZONES. .MSP...NONE. SCOTT NNNN mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 322 AM CDT SUN APR 11 1999 MAIN FCST CONCERN IS SNOW AMOUNTS FOR TDY IN NW WI AND NORTH SHORE. MODELS IN FAIR AGREEMENT WITH SFC LOW TREND...BUT TEND TO DIFFER ALOFT. RUC SEEMS TO HAVE A GOOD HANDLE ON PVA/NVA. KEPT WITH ETA BEYOND RUC FCST PERIOD AS ETA MOST SIMILAR WITH RUC. NOT AS MUCH MOISTURE TO WORK WITH AS PREVIOUSLY ADVERTISED ON FRIDAY NIGHT'S MODEL RUN. THIS HAS HELPED KEEP DOWN SNOW AMOUNTS. STILL SOME ISENTROPIC LIFT THIS MORNING...BUT DOWN SLOPE THIS AFTN. AS UPPER LOW AND ASSOCIATED VORT MOVE EAST...PRECIP TO MOVE EAST AS WELL. SINCE THIS WILL CAUSE SNOW ADDITIONAL AMOUNTS OF ONLY AN INCH OR TWO...AND ALSO SINCE A LOT OF THE WET SNOW HAS BEEN MELTING UPON CONTACT WITH THE WARM SFC...WILL NOT EXTEND ADVISORY INTO TODAY. MAY SEE SOME RAIN MIXED WITH THE SNOW IN THE SRN TIER OF NW WI AND ALSO RIGHT NEAR LAKE SUPERIOR. TROUGH EXTENDS BACK ACROSS SRN CWA TDY...BUT WASHES OUT TONIGHT AS HIGH PRESSURE MOVES IN. SHOULD SEE SOME DECREASE IN CLOUDS ACROSS THE NORTH BUT AT A SLOWER RATE. NO OTHER CHANGES TO LATER PERIODS. FAN RUNNING WARMER THAN NGM AGAIN. CLOUDS SHOULD KEEP HIGHS DOWN TDY...BUT UP TNGT. SO AGAIN WILL GO WITH A COMPROMISE. COORD WITH MPX AND GRB. .DLH...NONE. TAP NNNN mn STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1025 AM EDT SUN APR 11 1999 SHORT: THINGS SEEM TO BE PROGRESSING SLGTLY FSTR THAN PRVSLY FCST...AND CERTAINLY QUIKER THAN 12Z RUC WAS INDICATING AS FAR AS PCPN. KOKX 88D ALREADY SHWG ECHOES INTO WRN/CNTRL NJ THO OBS INDICATE PCPN REACHING GRND STL BACK IN ERN PA. WL TAKE A BIT OF TIME TO MOISTEN AMS ENUF TO SEE PCPN GET TO GRND...BUT LIKE PRVS PCKG/S POPS FOR THE MST PT. HV MADE SUM SLGT ADJUSTMENTS TO 1ST PD...MSTLY IN INITIAL WNDS. TEMPS LOOK OK AND LTL CHG WL BE MADE. LONGER TERM: WL WAIT FOR ENTIRE 12Z MDL SUITE TO ARV BFR MAKING ANY CHGS. PTYP STL A ? FOR TNGT...CAN/T WAIT TO SEE NEW MDL SNDGS (NOT). MARINE: PER COORD W/ PHI...WL RAISE SCA AS CLS ENUF TO 12HR WINDOW AND SEAS ARE GETTING CLS TO OUR 6 FT CRIT ANYWAY. PLUS...NOTICED THAT BOX HAS RAISED GLW SO THIS IS GUD FIT. DID MAKE ADJUSTMENTS TO SEAS IN LTR PDS TO BETTER FIT LCL STUDIES. CORRECTED CWF FIXED 2ND/3RD PD WNDS. PRELIM WRKZFP/WRKCWF ARE AVBL IN BIG BLUE FOR REQ AND COMMENTS. FINALS OUTTA HERE BTWN 1430-1445Z. .NYC...SCA ALL CSTL WTRS..LI SOUND..NY HRBR ANZ330-335-338-350-353-355. REYNOLDS NNNN ny STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH/DURHAM, NC 150 PM EDT SUN APR 11 1999 MOST CRITICAL PART OF FORECAST WILL BE FIRST 6 HOURS AS SCATTERED CONVECTION SHOULD BEGIN TO FIRE NEXT HOUR OR TWO. LATEST RUC AND MAPS POINT TOWARD AREAS ALONG AND NORTH OF I-40 HAS HAVING GREATEST POTENTIAL FOR CONVECTION LATE THIS AFTERNOON AND EARLY THIS EVENING...BASICALLY ALONG AND NORTH OF WARM FRONTAL BOUNDARY (21-01Z). LATEST KRAX VWP INDICATES 50KNOT WINDS DOWN TO 4K FEET SO EXPECT DAMAGING WINDS TO BE MAIN SEVERE WEATHER THREAT. CELLS NEAR/N OF WARM FRONT WILL BE IN AREAS OF GREATEST LOW LEVEL SHEAR THUS BEST POTENTIAL FOR ROTATION. AREAS NR SC BORDER WILL LIKELY BE MODERATELY CAPPED SO WILL PLACE LOWEST POPS THERE (20-30%). EXPECT MOST OF CONVECTION TO BE EAST OF CWA BY 02Z AS SFC TROF MARCHES EASTWARD AND WESTERLY LOW LEVEL FLOW ADVECT MUCH DRIER AIR INTO AREA (DEWPOINTS CURRENTLY IN THE 30S ACROSS NRN AL-MID TN). WILL LIKELY INCLUDE "REMAINDER OF THE AFTERNOON" PERIOD TO COVER SCATTERED CONVECTION AS MOST ACTIVITY SHOULD BE EXITING REGION BY BEGINNING OF "OFFICIAL" TONIGHT PERIOD. MODELS IN FAIRLY GOOD AGREEMENT WITH UPPER AND LOW LEVEL FEATURES LATER TONIGHT THRU TUE. AFTER A CLEAR AND BREEZY NIGHT TONIGHT...A S/W SKIRTING AREA IN NW UPPER LEVEL FLOW WILL SPREAD STRATOCU ACROSS AT LEAST THE NRN HALF OF CWA MON. BRISK N WIND AND SKY BECOMING MOSTLY CLOUDY WILL KEEP TEMPS A FEW DEGS BELOW NORMAL. EXPECT WINDS TO ABATE LATE MON NIGHT/TUE AS SFC RIDGE BUILDS INTO REGION. EXPECT COLDEST NIGHT TO BE TUE NIGHT AS SFC RIDGE SETTLES OVER AREA. PREFER WARMER FWC TEMPS TONIGHT AS CAA DOESN'T COMMENCE UNTIL 12Z MON. WHERE DIFFERENCES NOTED MONDAY NIGHT...WILL LEAN TOWARD COMPROMISE AS WINDS MAY ABATE EARLY ENOUGH TO ALLOW TEMPS TO FALL BELOW WARMER FWC VALUES. RDU 49/63/36/63 3000 GSO 47/62/37/63 -000 .RDU...NONE. WSS NNNN nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 935 AM EDT SUN APR 11 1999 WM FNT IS SLOWLY WORKING ITS WAY NORTH THROUGH SOUTHERN SC. 09Z RUC HANDLES THE FNT WELL BUT LOOKS TO BE A COUPLE OF HOURS TOO FAST WITH IT. EXPECT THE FNT TO MOVE N OF THE FA AFT 18Z BRINGING BETTER INSTABILITY BACK TO THE AREA. 12Z SOUNDING FROM CHS HAD A LI OF ALMOST -7 WITH HIGH HELICITY. THINK THE HELICITY WILL DECREASE THROUGH THE AFTN BEHIND THE FNT AS THE WINDS COME AROUND TO THE SW AND BECOME MORE UNIDIRECTIONAL. FFC BEHIND THE WM FNT THIS AM HAD A HELICITY AROUND 90. AS NOTED BY SPC...PRE-FRONTAL TROUGH LOOKS TO SET UP AHEAD OF THE FNT ACROSS THE REGION AND THIS IS HINTED AT BY THE RUC. BEST MOISTURE CONV WILL BE ALONG THE TROF BUT LIMITING FACTOR TO TRW DEVELOPMENT IS GOOD LIFT. H7 S/WV IS PROGGED TO COME ACROSS THIS AFTN AND WILL BRING ENOUGH LIFT TO SPARK SOME DEVELOPMENT AND THINK CURRENT CHC POPS LOOK GOOD. LATEST VIS SATL SHOWS THE CLOUDS BREAKING UP NEAR AND AHEAD OF THE WM FNT SO WILL PROB BE ABLE TO GO WITH P/SUNNY THIS AFTN. TEMPS IN CURRENT FCST SHOULD BE OK ONCE WM FNT GOES THROUGH BUT MAY ADJUST SE NC DOWN A LITTLE HAS CLOUD COVER SHOULD HANG ON A LITTLE LONGER IN THIS AREA. CWF: CURRENT FCST LOOKS IN GOOD SHAPE FOR THIS AFTN WITH SE WINDS COMING AROUND TO THE SW BEHIND THE FNT. GOOD GRADIENT AND WAA SHOULD ALLOW SPEEDS TO COME UP BUT RUC STILL KEEPS SPEEDS UNDER SCA THROUGH 21Z. .ILM...NONE. IRELAND NNNN nc CENTRAL PENNSYLVANIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1050 AM EDT SUN APR 11 1999 REGIONAL RADAR LOOP SHOWING BAND OF STRATIFORM STEADY RAIN MOVING NE THRU PA THIS MORNING. STEADY PRECIP SHOULD HAVE CLEARED ALL BUT EXTREME NE ZONES BY NOON. WILL THEREFORE PHRASE AFTN FCST AS "SHOWERS" RATHER THAN "RAIN"...AND WILL LOWER POPS ACROSS THE BOARD. LATEST ETA AND RUC MODELS CONTINUE TO SUGGEST THAT SFC WARM FRT PUSHES INTO WESTERN PA THIS AFTN...JUST AHEAD OF APPROACHING CDFNT. IF THIS OCCURS...THUNDERSTORMS WILL LIKELY FORM WITH THE FROPA AND WEAKEN AS THEY MOVE INTO STABLE AIR MASS OVER CENTRAL PA. WILL KEEP MENTION FOR THUNDER THRU THE EVENING HOURS OVER ROUGHLY THE SOUTHERN HALF OF PA...AS SOUNDINGS SHOW ATMOS BECOMING MARGINALLY UNSTABLE ABV 850 MB. RAINFALL OF AROUND 0.5 INCHES THIS MORNING HAS FURTHER REDUCED THE FLASH FLOOD THRESHOLD OVER WESTERN PA. WITH THIS IN MIND...WILL KEEP THE FFA GOING FOR THE POSSIBILITY OF TSRA THIS AFTN AND EVENING OVER THE LAUREL HIGHLANDS. .CTP...FFA...THIS AFTERNOON THRU THIS EVE...LAUREL HIGHLANDS. FITZGERALD NNNN pa STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1007 AM EDT SUN APR 11 1999 DISC: 13Z ANALYSIS SHOWS CDFNT TO OUR W ALNG MTS AND WF NW TO SE ACRS THE CNTRL PTN OF THE STATE. SATELLITE SHOWING QUITE A BIT OF SUN ACRS MANY AREAS THIS MORNING...BUT CLDS ASSOCIATED WITH FNT ALNG THE MTS. AREA RADAR COMPOSITE SHOWING MOST OF THE PCPN TO OUR N. MORNING RUC A BIT FASTER THAN ETA IN BRINGING CDFNT ACRS THE STATE TDA. BUT BOTH MODELS NOT SHOWING MUCH IN THE WAY OF MOISTURE WITH THE CDFNT. BUT WITH DESCENT INSTABILITY AHEAD OF FNT ALONG WITH WARM TEMPS AND TDS IN THE MID 60S WL CONT WITH A SML POP ACRS THE REGION FOR THE AFT. AFT TEMPS LOOK ON TRACK...ADJUSTED TEMPS FOR CSTL AREAS OF CHS FA. .CAE...NONE. LCV NNNN sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1010 AM EDT SUN APR 11 1999 WEDGE SHAPED AREA OF SHRA/TSRA OVER MUCH OF THE FA ATTM IN FAVORABLE REA OD UPPER DIVERGENCE/LIFT BETWEEN NRN & SRN JETS. 12Z RUC SHOWS THAT WE ARE SOON TO LOSE THAT UPPER DIVERGENCE...AND WITH THE TIME OF THE DAY THE AREA OF SHRA SHOULD CONT TO WEAKEN. HAVE BEEN WATCHING TO SEE IF THE SRN EDGE OF THE SQUALL LINE FIRES AS IT MOVES INTO THE NC MTNS WHERE MSAS INDS A POOLING OF MOISTURE AND INCREASING INSTABILITY AS THE WARM FNT MOVES NWD. SFC FNT STILL IN ERN KY/E CEN TN. 88D SHOWS SOME WEAK RETURNS ALONG THAT...BUT NO LTG YET. 12Z RUC SHOWS THIS FNT MOVG OFF THE MTNS BETWEEN 18 & 21Z...WHICH LOOKS LIKE RESONABLE TIMING. DON/T THINK MOST OF THE CWA WILL HAVE ENUF TIME TO RECOVER TO WORRY ABOUT SVR...WITH EXCEPTION OF THE NC PIEDMONT & MY ERN VA PIEDMONT FROM DAN EWD. HOWEVER...VSB SAT SHOWS THERE WILL BE SOME BREAKS AHEAD OF THE COLD FNT FURTHER N IN WV & VA...SO STILL AT LEAST CHC POPS FOR THIS AFT. TEMPS SHOULD SHOOT UP INTO THE 70S ALL AREAS THAT THE WARM FNT CLEARS THIS AFT. TEMPS WILL ALSO STILL RISE LATE THIS AFT EVEN IN NERN SECTIONS WITH THE PASSAGE OF THE COLD FNT. .RNK... VA...NONE. NC...NONE. WV...NONE. JJ NNNN va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 933 AM EDT SUN APR 11 1999 CUR IR SAT DIPCTS THE OVERRUNING PRECIP QUITE NICELY ACRS SRN VA AND NE NC. HOWEVER BREAKS IN THE CLDS ARE OCCURNG ACRS SRN NC AND SC. THESE BREAKS COULD PLAY A MAJOR ROLE IN TODAY/S FCST. KAKQ 88-D SHOWS SH WITH SOME EMBEDDED TS MAINLY S AND W OF A LIME FM CHO TO RIC TO ECG. MOVEMENT IS SLOWLY E...BUT IS ERODING SOMEWHAT AS IT MOVES INTO THE DYER AIR MASS ACRS ERN VA AND MD. 13Z SFC ANALYSIS DIPCTS THE WM FRNT XTND E/W ACRS SRN NC. THIS IS APPROX 100 MI FARTHER N THAN BOTH RUC AND MESOETA HAD INDICATED. AS FOR THIS AFT...AM STILL TRYING TO GET A FEEL FOR HOW FAR N THE WRM FRNT WILL ACT GO. TEND TO BELIEVE THAT IT WILL SLICE THE NRN PART OF THE FA BY LATE AFT. WITH THIS IN MIND THINK CUR FCST IS PRETTY MUCH ON TRACK BUT WILL MONITOR TEMPS CLOSLY. AS FOR TSTM AND SVR THREAT...THINK BEST CH IS ACRS SRN VA AND NC. ATTM...DEWPTS JST TO THE S OF THE WARM FRNT ARE IN THE LWR 60S. SO XPCT DEWPTS TO CLIMB AT LEAST INTO THE UPR 50S TO LWR 60S IN NC ANS SRN VA ZNS. BOTH RUC AND MESOETA HINT AT A 45 TO 50 KNT JET AT H850 THIS AFT. SO BELIEVE THE MAJOR THREAT WLD BE A SQ LN SIT. MARINE...ADDED SCA FOR NEW PT COMFORT AND SOUTH DUE TO WNDS INCREASNG THIS AFT TO THE S OF THE WM FRNT. .AKQ...SCA BAY FROM NEW PT COMFORT TO CAPE HENRY...AND MD/VA ATLC CST. SHADE NNNN va INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 900 PM PDT SUN APR 11 1999 UPPER LOW CONTS TO SLIDE SSE ALONG THE CENTRAL CA COASTLINE AND WAS LOCATED WEST-SOUTHWEST OF POINT CONCEPTION AT 04Z. ALTHOUGH 00Z UPPER AIR DATA INDICATED 90KT JET MAX ON LEEWARD SIDE OF LOW OVER SOCAL...DATA ALSO EVIDENCES 120KT JET MAX DIGGING TO THE WEST WHICH SHOULD SLOW LOW/S EASTWARD EJECTION. ALONG THIS LINE...00Z RUC HAS FALLEN INTO AGREEMENT WITH AVN SHOWING SLOWER MOVEMENT AND BRINGING CIRCULATION INLAND BETWEEN LAX AND SAN ON MON. CLOUD TOPS HAVE BEGUN TO WARM OVER CWFA THIS EVE WITH PRECIP DECREASING OVER NORTHERN PORTIONS OF FORECAST AREA. ALTHOUGH PASSAGE OF FRONTAL BOUNDARY HAS SHIFTED LOW LEVEL GRADIENT TO NWLY...88D SHOWS LAYER CONFINED TO LOWEST 2K FEET AND STG DEEP SE FLOW ATOP SHOULD CONT TO ADVECT SOME WRAP-AROUND PRECIP NORTHWARD OVERNIGHT. NEVERTHELESS...AS REGION OF MAX UPPER DIFLUENCE MOVES SOUTH...BEST POTENTIAL FOR ADDITIONAL PRECIP WILL SHIFT TO SRN PORTIONS OF CWFA WITH SE FLOW ENHANCING PRECIP AMOUNTS OVER SRN AND ERN SLOPES OF KERN COUNTY MOUNTAINS. WILL THEREFORE MAINTAIN CURRENT SNOW ADVISORY ACROSS KERN MOUNTAINS AND NOT UPGRADE TO WINTER STORM WARNING AS BEST UVM AND COLDEST UA TEMPS SHOULD TRACK CLOSER TO LOW AND REMAIN WEST AND SOUTH OF CWFA...SHIFTING EAST OVERNIGHT. WILL PREPARE A MINOR UPDATE TO ADJUST WIND AND POPS IN A FEW LOCATIONS...HOWEVER MAJORITY OF PRESENT FORECAST LOOKS GOOD AT THIS TIME. .HNX...SNOW ADVISORY TONIGHT FOR THE KERN COUNTY MOUNTAINS ABOVE 4000 FEET. NESMITH NNNN ca EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 900 PM PDT SUN APR 11 1999 THE LAST IN A SERIES OF GULF OF ALASKA STORMS WILL MOVE ACROSS SOUTHERN CALIFORNIA TONIGHT. RAIN AND SNOW COULD BE HEAVY AT TIMES TONIGHT. SHOWERS WILL DECREASE MONDAY AS THE STORM MOVES EAST INTO ARIZONA. SNOW ADVISORIES ARE POSTED FOR THE MOUNTAINS THROUGH MONDAY MORNING. HIGH PRESSURE WILL BUILD ALONG THE WEST COAST WITH DRIER AND MUCH WARMER WEATHER FOR SOUTHERN CALIFORNIA BY MID WEEK. THE NGM IS SIMILAR TO THE ETA THROUGH 24 HOURS. AVAILABLE SOUNDINGS AND 850/700 MB TEMP PROGS INDICATE ONLY ANOTHER 2-5 DEGREES CELSIUS COLD AIR ADVECTION OVER FORECAST AREA IN THE MID LEVELS... AND THE BULK OF THIS NOT ARRIVING UNTIL AFTER 12Z. CURRENT FREEZING/SNOW LEVELS RANGING FROM A LOW OF 4000 FEET E END OF SAN GABRIEL MOUNTAINS TO AROUND 5000 FEET SAN BERNARDINO MOUNTAINS AND ABOVE 5500 FEET ELSEWHERE. THIS WILL ONLY LOWER SNOW LEVELS ANOTHER 1000 FEET ACROSS SAN BERNARDINO/RIVERSIDE/SANTA ANA MOUNTAINS... AND POSSIBLY AN ADDITIONAL 2000 FEET OVER THE SAN DIEGO COUNTY MOUNTAINS. BOTH THE 00Z RUC AND ETA TAKE THE IMPULSE ROTATING AROUND THE UPPER LOW INTO SAN DIEGO COUNTY. ETA QPF AMOUNTS GREATEST OVER SAN DIEGO COUNTY BETWEEN 06Z-18Z BUT ONLY A HALF INCH. RECENT SATELLITE PRECIPITATION ESTIMATE MESSAGE ALSO SUPPORTS DWINDLING CHANCE OF HEAVY PRECIPITATION ACROSS NORTHERN PORTION OF AREA IN SHORT TERM. WILL LOWER HEAVY SNOW WARNINGS TO ADVISORIES AND SHORTEN DURATION TIMES OVER SAN BERNARDINO AND RIVERSIDE MOUNTAINS...WILL CONTINUE URBAN/SMALL STREAM ADVISORY TILL MIDNIGHT FOR ORANGE COUNTY/SAN BERNARDINO INLAND EMPIRE WHERE HALF TO ONE INCH OF RAIN HAS FALLEN PER ALERT GAGES SO FAR AND TO COVER ADDITIONAL RUNOFF OFF FROM SANTA ANA MOUNTAINS/FOOTHILLS. WILL HIGHLIGHT POSSIBILITY OF MINOR FLOODING FOR SAN DIEGO COUNTY ZONES MONDAY MORNING. ONLY OTHER CHANGE ENVISIONED IS CUTTING BACK OR ELIMINATING THE POSSIBILITY OF TSTMS/HAIL FOR MOST ZONES. THE 11/12Z ENSEMBLE SUPPORTS BUILDING RIDGE FOR MUCH DESIRED WARMING BY MIDWEEK. QUICK LOOK AT EUROPEAN AND UK MET MODELS ARE ALSO IN AGREEMENT. SAN +700 .SAN...SNOW ADVISORY ALL MTNS URBAN/SMALL STREAM FLOODING...ORANGE COUNTY AND BALFOUR NNNN ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 915 PM EST SUN APR 11 1999 TROF MOVG SE THROUGH FA WITH WK RETURNS. UL SYS ACRS SERN LWR MI MOVG E WITH ANOTHER TROF JUST N OF FA. 21Z RUC WB PROFILES SUGGEST THAT TRACE PCPN MAY MIX WITH SN OVERNIGHT NRN THIRD CWA. WL UPDATE IN ZNS TO RMV POPS AND INDICATE SPOTTY TRACE EVENT AND ADJUST WINDS. .IWX...NONE PBM NNNN in AREA FORECAST DISCUSSION FOR EASTERN UPPER/NORTHERN LOWER MI NATIONAL WEATHER SERVICE GAYLORD MI 1016 PM EDT SUN APR 11 1999 THINGS ARE RAPIDLY QUIETING DOWN ACROSS PORTIONS OF NORTHERN LOWER MI. ALL WARNINGS AND ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. LATEST SFC ANALYSIS HAS 1006 MB LOW ACROSS WESTERN PA/NY BORDER...WITH BETTER-DEFINED CYC FLOW NOW CONFINED ACROSS THE SE QUADRANT OF LOWER MI. 500 MB LOW NOW IN THE VICINITY OF LAKE ERIE...HOWEVER UPR TROUGHING/VORT LOBE CONTINUES TO EXTEND NW FROM LOW TOWARD MN ARROWHEAD REGION. 00Z RUC INDICATES UPPER LEVEL TROUGING HOLDING IN PLACE THROUGH MUCH OF THE NIGHT ALONG AND SW OF A TRAVERSE CITY TO TAWAS CITY LINE... BASICALLY THE SW SECTOR OF NORTHERN LOWER MI. UPR RIDGING/NDVA REGIME CONFINED N OF THIS VORT LOBE WILL RESULT IN LESS CLOUD COVER OVERNIGHT ACROSS EASTERN UPPER AND THE NE HALF OF LOWER MI. AREA OF NDVA/UPR RIDGING WILL MOVE VERY LITTLE TO THE SOUTH OVERNIGHT...IF AT ALL. AS A RESULT...HAVE WORDED MOSTLY CLOUDY IN ZONES ALONG AND SW OF TRAVERSE CITY AND TAWAS...WITH MORE NOTICABLE CLEARING EXPECTED IN THESE AREAS BY OR AFTER DAYBREAK. TEMPS OVERNIGHT WILL PROBABLY BE A FEW DEGREES HIGHER THAN FWC (NGM) MOS...ESPECIALLY ACROSS THE SOUTHERN PORTIONS OF NORTHERN LOWER MI...IN LIGHT OF THE CLOUD COVER AND SOME LOW LVL MIXING (SFC WINDS AROUND 10 MPH). .APX...NONE. HURLEY NNNN mi AREA FORECAST DISCUSSION...CORRECTION NATIONAL WEATHER SERVICE BILLINGS MT 915 PM MDT SUN APR 11 1999 UPDATE FOR TEMPERATURES NEEDED FOR ZONES 029...035...AND 038. HAVE ALSO UPDATED ZONES 028...040...AND 041 FOR LOWER TEMPERATURES. WITH GENERALLY EAST WINDS OVER AFFECTED AREA EAST OF THE MOUNTAINS...TEMPERATURES COULD GO LOWER THAN FORECAST. WINDS ALSO WENT LIGHTER OUT WEST WHICH COULD ALSO CAUSE LOWER TEMPERATURES THERE AS WELL. OTHERWISE...GOING FORECASTS LOOK REASONABLE. LATEST RUC RUN FOR 12/00Z INDICATES SOUTHEAST TO SOUTH WINDS AS FAR WEST AS THE BILLINGS AREA LASTING THROUGH MUCH OF THE NIGHT. NOT MUCH MOISTURE TO SPEAK OF. HAVE BEEN NOTICING SOME HIGH LEVEL CLOUDS OVER WYOMING MAKING THEIR WAY NORTHEAST. THESE SHOULD NOT HAVE TOO MUCH OF AN EFFECT ON THINGS. DRIER AIR IS OVER THE AREA AS COMPARED TO LAST NIGHT. AM NOT LOOKING FOR FOG TO BE A PROBLEM THIS TIME. CHB BIL UN 028/064 034/062 028 520000 LVM .. 024/062 032/063 ... 520002 HDN .. 027/066 035/064 ... 520000 MLS .. 029/062 031/065 ... 520000 4BQ .. 028/062 029/065 ... 520000 BHK .. 027/061 027/064 ... 520000 SHR UN 028/063 032/064 027 520002 NNNN mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 835 PM MDT SUN APR 11 1999 UPDATE FOR TEMPERATURES NEEDED FOR ZONES 029...035...AND 038. WITH GENERALLY EAST WINDS OVER AFFECTED AREA...TEMPERATURES COULD GO LOWER THAN FORECAST. OTHERWISE...GOING FORECASTS LOOK REASONABLE. LATEST RUC RUN FOR 12/00Z INDICATES SOUTHEAST TO SOUTH WINDS AS FAR WEST AS THE BILLINGS AREA LASTING THROUGH MUCH OF THE NIGHT. NOT MUCH MOISTURE TO SPEAK OF. HAVE BEEN NOTICING SOME HIGH LEVEL CLOUDS OVER WYOMING MAKING THEIR WAY NORTHEAST. THESE SHOULD NOT HAVE TOO MUCH OF AN EFFECT ON THINGS. DRIER AIR IS OVER THE AREA AS COMPARED TO LAST NIGHT. AM NOT LOOKING FOR FOG TO BE A PROBLEM THIS TIME. CHB BIL UN 028/064 034/062 028 520000 LVM .. 028/062 032/063 ... 520002 HDN .. 027/066 035/064 ... 520000 MLS .. 029/062 031/065 ... 520000 4BQ .. 028/062 029/065 ... 520000 BHK .. 027/061 027/064 ... 520000 SHR UN 028/063 032/064 027 520002 NNNN mt AREA FORECAST DISCUSSION...UPDATED TO ADDRESS POPS NATIONAL WEATHER SERVICE WILMINGTON NC 923 PM EDT SUN APR 11 1999 MAY BE ABLE TO LEAVE POPS OUT ALTOGETHER. REMAINING SHOWERS NEAR FAY SHOULD STAY NORTH OF THE CWA. SHOWERS WEST OF FAY HAVE DISSIPATED. LATEST MSAS SFC ANALYSIS SHOWS LOW PRES TROF EXTENDING THRU EASTERN AND CENTRAL NC WITH A MESO LOW ALONG THE FRONT BETWEEN RDU AND FAY. THIS FEATURE IS GENERATING ANOTHER ROUND OF SCATTERED SVR TSTMS IN THE UNSTABLE AIRMASS OVER THE AREA. ADAP INDICATES LI'S OF -5 AND A BULLSEYE OF MOISTURE CONVERGENCE NEAR THE MESO FEATURE. THE STORMS ARE FAST MOVING AND IT APPEARS THAT THIS ROUND OF SVR ACTIVITY WILL REMAIN NORTH OF THE CWA LIKE THE LAST. THE LATEST RUC SEEMS TO HAVE A GOOD HANDLE ON THIS ACTIVITY AND PUSHES THE LOW LEVEL CONVERGENCE OFFSHORE BY 06Z. WITH TEMPS IN THE LOWER 80S AHEAD OF THE FRONT AND WSW FLOW...COULD SEE TEMPS RISE A COUPLE OF DEGREES OVER NEXT COUPLE OF HOURS... ESPECIALLY ACROSS EASTERN COUNTIES...BEFORE FALLING TO NEAR CURRENTLY FCST VALUES. DEWPOINTS SHOULD FALL INTO THE 40S AFTER MIDNIGHT BUT WINDS WILL STAY UP AND KEEP TEMPS FROM BOTTOMING OUT. CWF: CURRENT FCST LOOKS ON TRACK. WILL CONTINUE WITH SCA OVERNIGHT. BUOY 41004 INDICATES WIND GUSTING TO 25 KT AND SEAS APPROACHING 6 FT. WILL LIKELY REMOVE MENTION OF PRECIP FOR SC WATERS. .ILM...SMALL CRAFT ADVISORY SURF CITY NC TO S SANTEE RVR SC. MORGAN NNNN nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 905 PM EDT SUN APR 11 1999 LATEST MSAS SFC ANALYSIS SHOWS LOW PRES TROF EXTENDING THRU EASTERN AND CENTRAL NC WITH A MESO LOW ALONG THE FRONT BETWEEN RDU AND FAY. THIS FEATURE IS GENERATING ANOTHER ROUND OF SCATTERED SVR TSTMS IN THE UNSTABLE AIRMASS OVER THE AREA. ADAP INDICATES LI'S OF -5 AND A BULLSEYE OF MOISTURE CONVERGENCE NEAR THE MESO FEATURE. THE STORMS ARE FAST MOVING AND IT APPEARS THAT THIS ROUND OF SVR ACTIVITY WILL REMAIN NORTH OF THE CWA LIKE THE LAST. THE LATEST RUC SEEMS TO HAVE A GOOD HANDLE ON THIS ACTIVITY AND PUSHES THE LOW LEVEL CONVERGENCE OFFSHORE BY 06Z. WITH WIDELY SCATTERED SHRA WEST OF FAY WILL KEEP SLIGHT CHANCE POPS FOR NC COUNTIES UNTIL MIDNIGHT...AND WILL REMOVE POPS FOR SC COUNTIES. WITH TEMPS IN THE LOWER 80S AHEAD OF THE FRONT AND WSW FLOW...COULD SEE TEMPS RISE A COUPLE OF DEGREES OVER NEXT COUPLE OF HOURS... ESPECIALLY ACROSS EASTERN COUNTIES...BEFORE FALLING TO NEAR CURRENTLY FCST VALUES. DEWPOINTS SHOULD FALL INTO THE 40S AFTER MIDNIGHT BUT WINDS WILL STAY UP AND KEEP TEMPS FROM BOTTOMING OUT. CWF: CURRENT FCST LOOKS ON TRACK. WILL CONTINUE WITH SCA OVERNIGHT. BUOY 41004 INDICATES WIND GUSTING TO 25 KT AND SEAS APPROACHING 6 FT. WILL LIKELY REMOVE MENTION OF PRECIP FOR SC WATERS. .ILM...SMALL CRAFT ADVISORY SURF CITY NC TO S SANTEE RVR SC. MORGAN NNNN nc FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 855 PM CST SUN APR 11 1999 MINOR UPDATE NEEDED SERN ZONES. TEMPS AT PKD FALLING MORE IN LINE WITH BJI...WILL NEED LOWER MIN TEMPS THERE BY 5 DEGREES. ELSE REMAINING ZONES LOOK REASONABLE. IR IMAGERY SHOWS CLD DECK IN CENTRAL MN IS PERSISTING WITH UPPER LEVEL CLDS SPIRALLING AROUND CLSD H5 LOW IN WRN GREAT LAKES. 21Z RUC SHOWED BUILDING H5 RIDGE IN THE DAKOTAS OVERNIGHT WITH SFC RIDGING INTO THE RRV. CONTINUED DRYING FROM NORTH AND WEST SHOULD ERODED CLD DECK IN MN AND DECREASE CLDS IN ERN ZONES OVERNIGHT AS FORECAST. MID LVL SHEAR AXIS EXTENDS FROM YDN TO ABR...ACROSS ERN ND. SHEARING SHOULD HELP CLEAR OUT STRATOCU DECK IN CENTRAL ND AFTER SUNSET. .FGF...NONE GUST NNNN nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 910 PM EDT SUN APR 11 1999 LTST SFC ANAL PLACES CDFRNT JUST E OF I81 WHILE WRM FRNT AND MESO LOW LCTD ON A LINE FROM ECG-RWI-GSO. MEANWHILE...RAIN COOLED STABLE AIRMASS OVRHD PROVIDING ENVIRONMENT FOR LOW CLDS/FOG AND SPOTTY DRIZZLE. RDR LOOP INDCTG TSRAS GNRLY S OF WRM FRNT..WITH WDLY SCT SHRA DVLPG ALONG CDFRNT. UPR LVL LOW/TROF PROVIDING PCPN TO MY N. LAPS DATA CONTS THE STABLE AIRMASS OVR FA...THUS KEEPING ANY THREAT OF TSRA TO MY S...BUT WITH CDFRNT APPRCHG...WILL KEEP 20-30 POP IN NRN AREAS. NXT CONCERN IS CLD COVER. 21Z RUC INCRS WNDS FROM W-NW BEHIND FROPA ALONG WITH DCRG RH FIELDS & LWR DP TMPS OVRNITE...THUS DRYING OUT AIRMASS AND ALLOWING SOME CLRG. HOWEVER...RUC KEEPS ENUF MSTR NERN AREAS TO KEEP CLDS IN THRU OVRNITE HRS. WILL BEGIN TO CLR THINGS OUT AND INCRS WNDS AFTR FROPA. .AKQ...SCA BAY/SOUND AND ALL CSTAL SECT. 44 NNNN va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 321 AM CDT MON APR 12 1999 MAIN FCST PROBLEM IS CLD/PRECIP ACROSS ABOUT THE S HALF OF CWA. HAVE GONE MORE WITH NGM TDY AS SFC PATTERN IS CLOSEST TO THAT WHICH IS CURRENTLY OVER THE REGION. RUC ALSO SIMILAR. STUBBORN VORT KEEPING CLDS FROM GPZ-DLH-PKF AND SOUTH. SOME SHOWERS HAVE EVEN DEVELOPED TOWARD DANBURY...SIREN AND SPOONER. UNFORTUNATELY I AM UNABLE TO GET GROUND TRUTH OF TYPE OF PRECIP IN BURNETT AND WASHBURN COUNTIES. WAS FLURRIES ON EVENING SHIFT...BUT LIQUID BEING REPORTED AT RPD. WILL MENTION BOTH FOR THIS MORNING. VORT GRADUALLY PULLS OFF DURING DAY AND MID LVL RH ALSO DECREASES. SO SRN TIER SHOULD BECMG PARTLY CLOUDY. ELSEWHERE...ALL MODELS DO HINT AT SOME INCREASE IN 850MB MOISTURE. WILL STICK WITH PARTLY CLOUDY FOR NOW. FAN AND NGM FAIRLY CLOSE ON TEMPS OVER NEXT FEW PERIODS...WITH NGM JUST A TAD COOLER AT TIMES. WILL STICK WITH FAN AND WARMER TEMPS AS THIS HAS BEEN THE COMMON TREND FOR QUITE SOME TIME NOW. ALSO SNOW COVER IS VERY LIMITED. WITH LIGHT WINDS AND WARM INLAND TEMPS... COULD SEE A LAKE BREEZE THIS AFTN NEAR LAKE SUPERIOR. QUESTION WILL BE HOW WARM WILL LAKESIDE TEMPS GET BEFORE THIS OCCURS. WILL STICK WITH THE MID 40S WORDING FOR NOW. SW WINDS MAY BE HIGH ENOUGH ON TUE TO ALLOW TEMPS TO RISE THROUGH THE 50S LAKESIDE. .DLH...NONE TAP NNNN mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1115 AM EDT MON APR 12 1999 MORNING SOUNDINGS FROM DTX AND APX NOT SHOWING MUCH CHANCE FOR ANY CU DEVELOPMENT. IN ADDITION CLOUDINESS OVER WI PROGGED BY THE RUC TO STAY THERE THROUGH MOST OF THE DAY. THUS WILL GO WITH MOSTLY SUNNY. FORECASTED HIGHS LOOK ON TRACK. .GRR...NONE. NNNN mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1045 AM EDT MON APR 12 1999 LATEST SURFACE CHART SHOWING LOW PRESSURE SYSTEM THAT MOVED OVER NORTHERN OHIO SUNDAY...NOW LOCATED OVER THE ATLANTIC COAST WITH HIGH PRESSURE RIDGING BUILDING INTO THE WESTERN LAKES. STLT AND SURFACE OBSERVATIONS OVER NORTHERN LOWER AND EAST UPPER MI SHOWING SCT-BKN MID AND UPPER LEVEL CLOUDS MOVING OVER LAKE SUPERIOR...LAKE HURON AND NORTHERN LAKE MICHIGAN. CLOUDS ARE IN ASSOCIATION WITH MID LEVEL CONVERGENCE DUE TO WK VORT LOBE MOVING SLOWLY OVER WISCONSIN INTO LAKE MICHIGAN. 12Z RUC SHOWING THIS FEATURE TO REMAIN OVER LAKE MICHIGAN THIS AFTERNOON WITH 500/300 MSTR REMAINING AT 60 PERCENT OVER THE STRAITS AND NORTHEAST LOWER. WILL GO PARTLY SUNNY FOR EAST UPPER AND NORTHEAST LOWER MICHIGAN THIS AFTERNOON. DUE TO LATEST STLT TRENDS AND 12Z RUC MODEL SOUNDINGS FOR NORTHWEST LOWER...WILL GO MOSTLY SUNNY NORTHWEST LOWER. MARGINAL DAY FOR LAKE BREEZE...WITH MARGINAL LAKE/LAND TEMP DIFFERENCE FOR 950 MB WINDS AROUND 10 KNOTS. RECENT SNOWFALL OVER THE CENTRAL AND SOUTHERN PORTIONS OF THE FORECAST AREA WILL KEEP TEMPERATURES FROM RISING TO QUICKLY AND THEREFORE DIMINISHING THE QUICK DEVELOPMENT OF LAKE BREEZE TODAY. .APX...NONE. SWR NNNN mi FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 1015 AM CST MON APR 12 1999 FORECAST CHALLENGE FOR UPDATE CONCERNS CLOUD TRENDS AND TEMPS. PERSISTENT BAND OF SC ACROSS NORTH CENTRAL SHOWING SOME SIGNS EROSION LAST FEW PIX FROM VIS LOOP. RUC PICKED UP ON THIS PRETTY WELL AND LOOKING AT LOW LEVEL H9-H85 FLOW FROM RUC CLDS SHOULD CONTINUE TO DRIFT N-NE. WILL MENTION A BIT MORE CLOUD COVER OVER PROJECTED AREAS OTWS REMAINDER OF REGION SHOULD SEE PLENTY OF SUN. WK SFC LOW OVR NW MN/S ONT PROGGED TO GRADUALLY FILL DURING THE DAY. CURRENT TEMPS IN LINE WITH EXPECTED MAX TEMPS. MAY NEED TO LOW DVL AREAS SLIGHTLY OTWS NO CHANGES PLANNED. .FGF...NONE VOELKER NNNN nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 915 AM EDT MON APR 12 1999 CURRENT VISIBLE IMAGERY SHOWS CONSIDERABLE LOW LEVEL CLOUDINESS ACROSS MOST OF THE CWFA. HOWEVER...THERE IS CLEARING OCCURRING ACROSS THE NORTHWEST CWFA. THE PROBLEM FOR TODAY WILL BE HOW FAST THE DRIER AIR MOVES INTO THE REGION AND WHETHER THERE WILL BE SOME CUMULUS DEVELOPMENT. 09Z RUC MODEL INDICATES DRYING BETWEEN 925 MB AND 850 MB FROM NORTH TO SOUTH TODAY. ILN SOUNDING STILL SHOWS AN UNSTABLE LOW LEVEL LAYER FROM SURFACE TO 850 MB ( 9 DEGREES CELSIUS CHANGE)...AND THE RUC CONTINUES THIS TREND THROUGH 5 PM. THUS...WILL BASE FORECAST ON DRIER AIR MOVING INTO THE NORTHERN CWFA...AND GRADUAL DRYING ACROSS THE SOUTH WITH SOME CUMULUS DEVELOPMENT ON THE PERIPHERY OF THE EXITING LOW LEVEL CLOUD SHIELD. TEMPERATURES WILL BE A LITTLE TRICKY WITH MAX SUNSHINE TO THE NORTH AND LINGERING CLOUDS TO THE SOUTH. HOWEVER...BELIEVE CURRENT FORECAST HIGH OF AROUND 50 MOST AREAS SEEMS REASONABLE WITH THE AFOREMENTIONED GIVE AND TAKE SITUATION. .ILN...NONE HICKMAN NNNN oh EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OK 1010 AM CDT MON APR 12 1999 LATEST SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE NEAR OMA SLIDING EAST. SURFACE WINDS ACROSS OUR AREA HAVE VEERED AROUND TO THE EAST...KEEPING MOISTURE WELL TO THE SOUTH BUT ALSO CUTTING OFF COLD AIR ADVECTION OVER MOST OF OUR AREA EXCEPT AROUND BYV. MODIFIED SOUNDINGS FROM OUN/SGF/LZK/FWD SHOW THAT FIRST PD TEMPS IN THE CRNT FORECAST MAY BE A NOTCH OR TWO LOW. THIS IS ESPECIALLY SO IN SOUTHEAST OKLAHOMA AS THE MODIFIED 12Z FWD SOUNDING SHOWS LOWER 80S FOR HIGHS. 12Z RUC SHOWS AFTN TEMPS IN LINE WITH CRNT FCST...BUT ITS 15Z FCST TEMPS ARE ALSO QUITE LOW COMPARED TO CRNT OBSVD TEMPS. WILL ISSUE AN UPDATED FCST SOON WHICH BUMPS TEMPS UP AND IS MORE OPTIMISTIC ON SUNSHINE ALONG THE KS/MO BORDERS. FCSTID = 22 .TUL... OK...NONE. AR...NONE. NNNN ok