AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 900 PM EDT THU MAY 13 2004 ANY REMAINING CONVECTION OVER NW PORTIONS OF THE CWA HAS ALL BUT DISSIPATED THIS EVENING...SO PLAN ON REMOVING ALL POPS FOR THE REMAINDER OF THE NIGHT ON THE UPDATE. THE 00 UTC KTLH SOUNDING ALSO SHOWS FURTHER DRYING ACROSS THE REGION...AS THE 1.72" OF PW WED MORNING...HAS FALLEN ALL THE WAY TO .92" THIS EVENING. OVER THE COASTAL WATERS...WEAK RIDGING HAS TEMPORARILY BUILT IN...CAUSING WINDS TO RAPIDLY DROP OFF AND BECOME VARIABLE THIS EVENING...BUT STILL EXPECT THE MAIN RIDGE TO THE E TO RE-ESTABLISH A GENERAL E-SE FLOW DURING THE NEXT FEW HOURS. $$ GOULD .PREV DISCUSSION... ******************************************************************** AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 243 PM EDT THU MAY 13 2004 .SYNOPSIS...AT UPPER LEVELS, WE SEE A LARGE AMPLITUDE LONG WAVE PATTERN WITH A TROUGH AXIS OVER THE ROCKIES AND NRN HIGH PLAINS AND A RIDGE AXIS ALONG THE ERN U.S. SEA BOARD N INTO QUEBEC. AN ELONGATED VORT LOBE EXTENDS FROM INDIANA S ACROSS AL. THE SRN PORTION OF THIS FEATURE IS RESPONSIBLE FOR AN ISOLATED AREA OF CONVECTION OVER S CENTRAL AL. SOME ROTATION IS EVIDENT WITHIN THIS AREA ON THE KEVX RADAR. SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED E OF NC RIDGING WWD ACROSS THE SERN STATES. A COLD FRONT IS MOVING VERY SLOWLY SEWD ACROSS THE UPPER MS VALLEY AND CENTRAL PLAINS STATES. THE 12Z KTLH SOUNDING SHOWS LESS INSTABILITY AND MOISTURE THAN 24 HOURS AGO WITH THE PW OF 1.4 INCHES. FOR A MODIFIED PARCEL, THE CAPE IS 1400 J/KG AND THE LI -5. WE ARE THEREFORE NOT EXPECTING THE COVERAGE WE SAW YESTERDAY AFTERNOON. && .SHORT TERM...TONIGHT THROUGH SUN. THE MODELS ARE IN GOOD AGREEMENT WITH THE EVOLUTION OF THE LARGE SCALE FEATURES. THE UPPER LEVEL PATTERN WILL DEAMPLIFY OVER THE WEEKEND WITH ZONAL FLOW ACROSS THE NRN CONUS BY SUN. THE MODELS ALL SHOW DRIER MOVING IN FROM THE E IN THE 850-700 MB LAYER BEGINNING TONIGHT AND CONTINUING THROUGH SAT NIGHT. THE PW DROPS BELOW 1.25 INCHES FOR THE NEXT 2 AFTERNOONS ACROSS THE BIG BEND. WE THEREFORE ANTICIPATED LESS OF A CONTRIBUTION FROM THE E COAST SEA BREEZE ON FRI AND SAT AND WILL GENERALLY ACCEPT A BLEND OF THE LOW MOS POPS. THE COLD FRONT IS STILL PROGGED TO STALL NW OF THE FORECAST AREA DURING THIS TIME. ITS CLOSEST APPROACH WILL BE ON SUN. THE GFS ALLOWS THE FRONT TO GET A BIT CLOSER TO US THAN THE ETA. WE FAVOR THE ETA IN THIS REGARD. HOWEVER, THE IDEA OF SLIGHTLY HIGHER POPS NW THAN SE ON SUN STILL LOOKS GOOD. THIS EVENING'S POPS WILL BE BASED ON RADAR AND SATELLITE TRENDS, BUT DO NOT ANTICIPATE GOING HIGHER THAN 20 ANYWHERE AFTER 00Z. .LONG TERM...SUN NIGHT THROUGH THU. THE FRONT SHOULD BE DISSIPATED OR AT LEAST HAVE RETREATED NWD BY MON. THIS WILL LEAVE THE FORECAST AREA IN THE FAMILIAR DEEP LAYER RIDGING PATTERN WE'VE SEEN FOR MUCH OF THIS SPRING. SURFACE HIGH PRESSURE WILL REMAIN CENTERED OFF THE NC COAST AND RIDGE WWD ACROSS DIXIE WITH THE AXIS N OF THE LOCAL AREA. THIS WILL KEEP OUR LOW LEVEL WINDS GENERALLY OUT OF THE E OR SE. WHILE THE NRN PART OF THE UPPER LEVEL RIDGE WILL BECOME FLATTENED, HEIGHTS WILL REMAIN HIGH OVER THE SERN STATES WITH THE BELT OF WESTERLIES WELL TO OUR N. TEMPS WILL BE AT OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. DAYTIME SEA BREEZES WILL HELP SPARK AFTERNOON SHOWERS AND STORMS, BUT COVERAGE SHOULD REMAIN IN THE ISOLATED TO SCATTERED RANGE. && .MARINE...WINDS AT THE OFFSHORE BUOYS BRIEFLY PEAKED ABOVE 15 KT, IN THE EXERCISE CAUTION RANGE WITH SEAS 4-5 FT. RUC FORECASTS INDICATE THAT THE TREND OF A LOOSENING PRESSURE GRADIENT OBSERVED IN OBJECTIVE ANALYSES WILL CONTINUE THIS AFTERNOON, SO WE DON'T ANTICIPATE ANY HEADLINES. IN FACT, THE BROKEN RECORD FORECAST WILL CONTINUE ON THE WATERS WITH E TO SE WINDS OFFSHORE AND E WINDS GIVING WAY TO AFTERNOON SEA BREEZES EACH DAY ACROSS THE NEAR SHORE LEGS EACH DAY THROUGH TUE. && .FIRE WEATHER...LOW LEVEL MOISTURE SHOULD BE SUFFICIENT TO PRECLUDE RED FLAG CONDITION THROUGH THE FORECAST PERIOD. HOWEVER, WE WOULD NOT BE SURPRISED TO SEE THE RH DIP BELOW 40% BRIEFLY ON FRI AND SAT AFTERNOONS. && .PRELIMINARY POINT TEMPS/POPS... TLH 65 87 63 86 / 10 10 10 20 PFN 69 83 68 84 / 10 20 10 20 DHN 67 85 65 85 / 20 20 10 30 ABY 65 87 64 86 / 10 20 10 30 VLD 64 87 63 87 / 20 10 10 20 CTY 64 88 64 87 / 10 10 10 20 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. && $$ WOOL/18 fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 243 PM EDT THU MAY 13 2004 .SYNOPSIS...AT UPPER LEVELS, WE SEE A LARGE AMPLITUDE LONG WAVE PATTERN WITH A TROUGH AXIS OVER THE ROCKIES AND NRN HIGH PLAINS AND A RIDGE AXIS ALONG THE ERN U.S. SEA BOARD N INTO QUEBEC. AN ELONGATED VORT LOBE EXTENDS FROM INDIANA S ACROSS AL. THE SRN PORTION OF THIS FEATURE IS RESPONSIBLE FOR AN ISOLATED AREA OF CONVECTION OVER S CENTRAL AL. SOME ROTATION IS EVIDENT WITHIN THIS AREA ON THE KEVX RADAR. SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED E OF NC RIDGING WWD ACROSS THE SERN STATES. A COLD FRONT IS MOVING VERY SLOWLY SEWD ACROSS THE UPPER MS VALLEY AND CENTRAL PLAINS STATES. THE 12Z KTLH SOUNDING SHOWS LESS INSTABILITY AND MOISTURE THAN 24 HOURS AGO WITH THE PW OF 1.4 INCHES. FOR A MODIFIED PARCEL, THE CAPE IS 1400 J/KG AND THE LI -5. WE ARE THEREFORE NOT EXPECTING THE COVERAGE WE SAW YESTERDAY AFTERNOON. && .SHORT TERM...TONIGHT THROUGH SUN. THE MODELS ARE IN GOOD AGREEMENT WITH THE EVOLUTION OF THE LARGE SCALE FEATURES. THE UPPER LEVEL PATTERN WILL DEAMPLIFY OVER THE WEEKEND WITH ZONAL FLOW ACROSS THE NRN CONUS BY SUN. THE MODELS ALL SHOW DRIER MOVING IN FROM THE E IN THE 850-700 MB LAYER BEGINNING TONIGHT AND CONTINUING THROUGH SAT NIGHT. THE PW DROPS BELOW 1.25 INCHES FOR THE NEXT 2 AFTERNOONS ACROSS THE BIG BEND. WE THEREFORE ANTICIPATED LESS OF A CONTRIBUTION FROM THE E COAST SEA BREEZE ON FRI AND SAT AND WILL GENERALLY ACCEPT A BLEND OF THE LOW MOS POPS. THE COLD FRONT IS STILL PROGGED TO STALL NW OF THE FORECAST AREA DURING THIS TIME. ITS CLOSEST APPROACH WILL BE ON SUN. THE GFS ALLOWS THE FRONT TO GET A BIT CLOSER TO US THAN THE ETA. WE FAVOR THE ETA IN THIS REGARD. HOWEVER, THE IDEA OF SLIGHTLY HIGHER POPS NW THAN SE ON SUN STILL LOOKS GOOD. THIS EVENING'S POPS WILL BE BASED ON RADAR AND SATELLITE TRENDS, BUT DO NOT ANTICIPATE GOING HIGHER THAN 20 ANYWHERE AFTER 00Z. .LONG TERM...SUN NIGHT THROUGH THU. THE FRONT SHOULD BE DISSIPATED OR AT LEAST HAVE RETREATED NWD BY MON. THIS WILL LEAVE THE FORECAST AREA IN THE FAMILIAR DEEP LAYER RIDGING PATTERN WE'VE SEEN FOR MUCH OF THIS SPRING. SURFACE HIGH PRESSURE WILL REMAIN CENTERED OFF THE NC COAST AND RIDGE WWD ACROSS DIXIE WITH THE AXIS N OF THE LOCAL AREA. THIS WILL KEEP OUR LOW LEVEL WINDS GENERALLY OUT OF THE E OR SE. WHILE THE NRN PART OF THE UPPER LEVEL RIDGE WILL BECOME FLATTENED, HEIGHTS WILL REMAIN HIGH OVER THE SERN STATES WITH THE BELT OF WESTERLIES WELL TO OUR N. TEMPS WILL BE AT OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. DAYTIME SEA BREEZES WILL HELP SPARK AFTERNOON SHOWERS AND STORMS, BUT COVERAGE SHOULD REMAIN IN THE ISOLATED TO SCATTERED RANGE. && .MARINE...WINDS AT THE OFFSHORE BUOYS BRIEFLY PEAKED ABOVE 15 KT, IN THE EXERCISE CAUTION RANGE WITH SEAS 4-5 FT. RUC FORECASTS INDICATE THAT THE TREND OF A LOOSENING PRESSURE GRADIENT OBSERVED IN OBJECTIVE ANALYSES WILL CONTINUE THIS AFTERNOON, SO WE DON'T ANTICIPATE ANY HEADLINES. IN FACT, THE BROKEN RECORD FORECAST WILL CONTINUE ON THE WATERS WITH E TO SE WINDS OFFSHORE AND E WINDS GIVING WAY TO AFTERNOON SEA BREEZES EACH DAY ACROSS THE NEAR SHORE LEGS EACH DAY THROUGH TUE. && .FIRE WEATHER...LOW LEVEL MOISTURE SHOULD BE SUFFICIENT TO PRECLUDE RED FLAG CONDITION THROUGH THE FORECAST PERIOD. HOWEVER, WE WOULD NOT BE SURPRISED TO SEE THE RH DIP BELOW 40% BRIEFLY ON FRI AND SAT AFTERNOONS. && .PRELIMINARY POINT TEMPS/POPS... TLH 65 87 63 86 / 10 10 10 20 PFN 69 83 68 84 / 10 20 10 20 DHN 67 85 65 85 / 20 20 10 30 ABY 65 87 64 86 / 10 20 10 30 VLD 64 87 63 87 / 20 10 10 20 CTY 64 88 64 87 / 10 10 10 20 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. && $$ WOOL/18 fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 1245 PM CDT THU MAY 13 2004 .DISCUSSION... THIS MORNING'S FCST ISSUES HOVER OVER THE NEXT THREE PERIODS. AS OF 07Z THE LOT AND REGIONAL 88DS ARE SENSING SCATTERED WEAK ELEVATED SHALLOW CONVECTION ACROSS THE REGION...MATURING MCS UNDERWAY FROM SRN IA AND POINTS SOUTH. PER PROFILER, SAT AND UPSTREAM SNDGS...EXPECTING ISENTROPICALLY ENHANCED, DEEP LAYER MOISTURE SOURCED PRECIP TO CONTINUE AS HIT OR MISS THROUGH THE MORNING. THE NEXT ISSUE CONCERNS TODAY'S AFTERNOON AND OVERNIGHT CONVECTION. LATEST FSL RUC-20 AND ETA DEVELOP LOWEST 50 AND 100 MB MIXED LAYER PARCEL CAPE ON THE ORDER OF 1600 J/KG LATE THIS AFTERNOON ACROSS THE CNTRL AND WRN PORTIONS OF THE CWA. THOUGH POTENTIAL THERMO INSTABILITY WILL BE GREATER THAN THAT OF THE PAST SEVERAL DAYS, MID AND UPR-LVL FLOW IS PROGGED TO BE WEAK UNTIL AFTER 12Z TOMORROW. UNLIKE THIS PAST EVENING, TONIGHT'S APPROACHING MID-LVL S/WV TROUGH WILL NOT BE AS AMPLIFIED NOR WILL THE FEATURE INDUCE A TIGHTENING HEIGHT GRADIENT THEREBY MINIMIZING MESOSCALE FLOW AUGMENTATION. COMPARISON OF REAL SNDG DATA VS. ETA BUFKIT SNDGS INDICATE WET-BULB ZERO HEIGHTS SHOULD REMAIN AS THE PAST FEW DAYS...AROUND 11 KFT. GIVEN THE ANTICIPATED WEAK FLOW AND SUBSEQUENT SLOW STORM MOTION SUPERIMPOSED WITH THE AMPLE DEEP LAYER MOISTURE AND CAPE, LOCALLY HEAVY RAINFALL APPEARS THE GREATEST CONCERN DUE TO CONVECTIVE OVERTURNING. WILL EMPHASIS HYDRO CONCERNS IN THE GRIDS AND UPCOMING HWO. ADDITIONALLY, AFTER DIRECT COORDINATION WITH THE SPC...CURRENT THOUGHT IS A FEW STORMS MAY BECOME MARGINALLY SVR THIS AFTERNOON AND EVENING. 3/4 TO 1 INCH HAIL POSING THE LARGEST THREAT...SEE 06Z DAY-1 FOR 5 PERCENT HAIL/WIND CONTOURING...SVR WIND SHOULD BE LESS OF A THREAT TONIGHT COMPARED TO LAST GIVEN NEAR MOIST ADIABATIC LAPSE RATES ABOVE THE LFC AND WEAKER H9-H7 FLOW. THE ACTIVITY WILL CONTINUE INTO FRI MORNING BEFORE SLOWLY ENDING FROM WEST TO EAST AS A COLD FRONT (AND MID-LVL TROUGH AXIS) PROGRESSES THROUGH NRN IL/IN. THE SHOWERS SHOULD PERSIST ACROSS NW IN UNTIL EVENING. AS FOR THE WEEKEND, MILD AND DRY WEATHER WILL BE THE RULE. THE EXTENDED PERIODS WERE MAINTAIN FROM THE PREVIOUS ISSUANCE. AEP && .AVIATION... FOR 18Z TAFS...17Z MSAS ANALSYIS DEPICTING SURFACE COLD FRONT EXTENDING FROM NORTHEAST WISCONSIN SOUTHWEST INTO EASTERN MISSOURI. PLENTY OF LOW LEVEL RH LINGERING AHEAD OF THIS BOUNDARY WITH GENERALLY MVFR CIGS ACROSS AREA TERMINALS THIS AFTERNOON. MOST CONCENTRATED AREA OF RAIN WITH EMBEDDED -TSRA CURRENTLY WORKING THROUGH CENTRAL WISCONSIN DOWNSTREAM OF MID LEVEL SHORT WAVE TROUGH AXIS ACROSS FAR WESTERN WISCONSIN WITH GOOD MID LEVEL CYCLONIC FLOW INFERRED FROM PROFILERS. THIS SHORT WAVE SHOULD CONTINUE TO LIFT NORTHEAST EXITING CWA IN 22Z-00Z TIME FRAME. AS THIS WAVE LIFTS NORTHEAST LOW LEVEL BOUNDARY EXPECTED TO SAG FURTHER SOUTH TO NEAR KRFD AROUND 03Z THEN ACROSS KMDW/KORD/KDPA IN THE 05Z-08Z TIME FRAME. ANOTHER SHORT WAVE IS EXPECTED TO LIFT NORTHEAST OUT OF CENTRAL PLAINS INTO CENTRAL IL TONIGHT SPREADING RAIN BACK INTO CWA AFTER 06Z. MID LEVEL LAPSE RATES ON ORDER OF 6 DEG C/KM AND ALTHOUGH THUNDER STILL A POSSIBILITY...DO NOT HAVE HIGH ENOUGH CONFIDENCE GIVEN MARGINAL INSTABILITY AND RATHER WEAK UPPER FORCING TO INCLUDE IN TAF. NDM && .LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LK MI...NONE. $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 918 AM CDT THU MAY 13 2004 .DISCUSSION...OTHER THAN TORNADO WATCH IN EFFECT FOR PORTIONS OF SE TEXAS...NOT PLANNING ON ANY UPDATES AT THIS TIME. BEST INSTABILITY CONTINUES TO BE IN SE TX...IN LA THE ATMOSPHERE HAS BEEN SOMEWHAT WORKED OVER AND PROBABLY WONT BE PRIMED UNTIL THE AFTERNOON. 15 && .PREVIOUS DISCUSSION...AN UPPER AIR DISTURBANCE OUT OF SOUTH TEXAS WILL BE MOVING THROUGH THE FORECAST AREA TODAY. SINCE THE ATMOSPHERE AND THE GROUND IS ALREADY SATURATED FROM EXCESSIVE RAINFALL RECENTLY...A FLOOD WATCH HAS BEEN ISSUED FOR TODAY. MORE DISTURBANCES MOVING OUT OF AN UPPER LEVEL TROF OVER THE WESTERN STATES WILL LIKELY GIVE US A REPEAT RAIN EVENT ON FRIDAY. A FRONTAL SYSTEM SAGGING TO THE COAST ON SATURDAY WILL PROVIDE A FOCUS FOR EVEN MORE RAIN AND THUNDERSTORMS. HIGH PRESSURE BUILDING FROM THE EAST WILL END THIS WET AND STORMY PATTERN ON SUNDAY. && .DISCUSSION...WENT A BIT LOWER ON TEMPS TODAY FROM THE EXPECTED RAINFALL WHICH SHOULD DRAG DOWN SOME RAIN COOLED AIR. PWS EXCEED 1.5 INCHES WITH K-INDICES OVER 30 AND MEAN RHS EXCEEDING 70%. DEW POINT LINE (ISODROSOTHERM) OF 75F FROM LCH TO CLL THIS MORNING...VERY IMPRESSIVE MOISTURE. ONCOMING NEGATIVELY TILTED SHORTWAVE COMING OUT OF S TEXAS IS A BIT SLOWER ON RUC THAN MESOETA...HOWEVER IR SATELLITE EXTRAPOLATION HAS THIS FEATURE INTO THE FORECAST AREA BY MID-MORNING...NOT FAR OFF MESOETA MOVEMENT. WILL MENTION HEAVY RAINFALL AND CANNOT RULE OUT PULSE SEVERE DUE TO THE NEG TILT TROF. ADDITIONAL SHORTWAVE ENERGY WILL BOOST POPS TO LIKELY AGAIN ON FRIDAY. SATURDAY GOING CATEGORICAL WITH ETA MOVEMENT OF FRONT TO THE COAST WHERE IT WILL LINGER DURING THE DAY. THETA RIDGE AT H7 WILL HELP ENHANCE PRECIP. RIDGE BUILDS IN FROM EAST AT SURFACE NEXT WEEK...AND ALOFT ALONG THE SOUTHERN STATES WHICH SHOULD HELP KEEP PRECIP BELOW CLIMO. THANX FOR THE COORD JAN...LIX...HGX. MARINE...KEEPING WINDS JUST BELOW SCA CATEGORY. && .PRELIMINARY POINT TEMPS/POPS... BPT 79 73 82 66 / 60 30 60 30 LCH 79 71 79 66 / 60 40 70 40 LFT 81 69 81 67 / 70 40 70 40 AEX 78 69 77 63 / 70 40 70 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...FLOOD WATCH...TODAY. TX...FLOOD WATCH...TODAY...TORNADO WATCH FOR TYLER...JASPER..HARDIN TIL 2 PM. && $$ 11 la AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TAUNTON MA 1200 PM EDT THU MAY 13 2004 .SHORT TERM... THIS AFTERNOON AND TONIGHT BACKDOOR FRONT HAS PUSHED INTO THE CT VALLEY...AND RUC/BOX ETA-10 ONLY SLIDE IT A LITTLE FARTHER W THIS AFTERNOON. AIRMASS WILL BECOME MORE UNSTABLE TO OUR W ACROSS NEW YORK STATE AND NJ/PA...BUT OUR CT VALLEY ZONES WILL REMAIN ON THE EDGE OF THE INSTABILITY GRADIENT. THEREFORE WE WILL LEAVE CHANCE POPS IN THE WESTERN ZONES FOR THE AFTERNOOON. ENVIRONMENT WILL ONCE AGAIN FAVOR PULSE STORMS WITH POTENTIAL FOR LOCALLY HEAVY RAINFALL AND ISOLATED SEVERE WEATHER...BUT MOST (IF NOT ALL) OF THIS SHOULD BE CONCENTRATED OUTSIDE OUR FORECAST AREA. LIGHT WINDS WILL PROMOTE SLOW MOVING STORMS AND WE COORDINATED ON THE FLASH FLOOD POTENTIAL WITH ALY/OKX. WE FEEL THAT OUR WESTERN MA AND NORTHERN CT ZONES WILL BE TOO FAR REMOVED FROM DEEPER INSTABILITY TO JUSTIFY A FLASH FLOOD WATCH AT THIS TIME. STORMS SHOULD DEVELOP ALONG TERRAIN FEATURES WITH ADDITIONAL ACTIVITY FORMING ON OUTFLOW BOUNDARIES DURING THE AFTERNOON. FORECASTS WERE UPDATED TO ADJUST TEMPERATURES AND SKY COVER FOR THE AFTERNOON. PERSISTENT ONSHORE FLOW WILL PRODUCE FOG AND LOW CLOUDS TONIGHT...ESPECIALLY ALONG THE S COAST. .LONG TERM... FRI THROUGH NEXT THU FORECAST THROUGH THE WEEKEND STILL LOOKS VALID...AS THE COLD FRONT PUSHES THROUGH NEW ENGLAND SAT NIGHT/EARLY SUN WITH SHOWERS AND THUDERSTORMS AHEAD OF IT. WE WILL NEED TO ASSESS THE POTENTIAL FOR SEVERE WEATHER IN LATER FORECASTS PER SPC DAY 3 OUTLOOK...SINCE THERE IS SOME QUESTION AS TO THE DEGREE OF INSTABILITY BECAUSE OF CLOUD COVER. FRONT SHOULD BE MOVING OFF THE S COAST SUN MORNING...SO WE ARE PLANNING TO LOWER POPS SUN AND SHOW A CLEARING TREND FROM N TO S. THIS IS SUPPORTED BY ENSEMBLES AS WELL AS 00Z GFS AND HPC PROGS. FRONT BEGINS TO RETURN N TUE WHICH PUTS US BACK INTO THE WARM SECTOR...THEN ANOTHER COLD FRONT MOVES E FROM THE GREAT LAKES WITH ANOTHER CHANCE OF SHOWERS/THUNDERSTORMS LATE TUE AND TUE NIGHT. THIS FRONT SHOULD BE MOVING OFF THE COAST WED MORNING...SO WE ARE THINKING OF CHANCE POPS EARLY WED FOLLOWED BY CLEARING. HIGH PRESSURE DOMINATES THU...AND CONSENSUS AMONG OUR NEIGHBORING OFFICES IS TO KEEP POPS BELOW CHANCE DESPITE THE NEXT WARM FRONT LIFTING NE FROM THE OHIO VALLEY. && .MARINE... SMALL CRAFT ADVISORY REMAINS POSTED FOR SEAS ON THE OUTER WATERS FROM THE MERRIMACK RIVER AROUND CAPE COD TO NANTUCKET. && .AVIATION... PATCHY LIFR FOG/ST IN THE INTERIOR WHERE NO WSHIFT NE YET...OTRW VFR TDY BECOMNING WDSPRD IFR/LIFR IN ST/FOG/L LATE TONIGHT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR SEAS MERRIMACK RIVER TO PLYMOUTH AND PROVINCETOWN TO NANTUCKET. $$ SHORT TERM...WAS/EVT LONG TERM...JWD ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 945 PM EDT THU MAY 13 2004 .DISCUSSION... 00Z RAOBS/WV LOOP AND RUC ANALYSIS SHOW WRN TROF/ERN RDG UPR PATTERN ACRS NAMERICA...WITH FA DOMINATED BY SW FLOW ALF BTWN THESE LARGER SCALE FEATURES. SFC STNRY FNT ON SE FLANK OF SHALLOW COOL AIRMASS OVER THE NW GRT LKS EXTENDS FM SE WI THRU NRN LWR MI. INTERACTION BTWN DYNAMICS/UPR DVGC ACCOMPANYING SHRTWV/ASSOCIATED 100KT H3 JET MAX TRACKING THRU NW ONTARIO AND AXIS OF HIER PWAT ALG H85 FNT (00Z PWAT/KINX 1.45 INCHES/31 AT GRB) IS CAUSING A RIBBON OF SCT-NMRS SHRA ACRS THE CNTRL CWA AT 01Z. THESE SHRA ARE MOVING NNE WITH DEPARING UPR JET/UPR DVGC...AND BACK EDGE OF ECHO NOW TO ONT-EGV- GRB. ARRIVAL OF DRIER AIR IN THE WAKE OF SHRTWV (00Z PWAT/KINX AT MPX 0.62 INCH/ 8) HAS ENDED PCPN TO THE SW (WHERE CLD TOP TEMPS ARE HIER PER IR IMAGERY)...BUT LO CLD LINGERS ACRS NW WI INTO THE MN ARROWHEAD UNDER INVRN AT H875 AS SHOWN ON MPX SDNG. 01Z TEMPS OVER THE FA RANGE FM ARND 40 OVER THE NW TO 54 AT MNM AND ISQ. OTRW...A NUMBER OF PLACES IN THE CWA RPRTG FOG...WITH VSBY AS LOW AS 1/4SM AT MNM. BUT OBS OVER MN SHOW LESS FOG WITH SOMEWHAT DRIER AIR INDICATED IN THE LLVLS WITH LWR DWPTS/DRIER AIR BLO INVRN AS SHOWN ON MPX/INL RAOBS. MAIN FCST CONCERNS TNGT ARE PCPN/FOG TRENDS. GIVEN RADAR TRENDS...DEPARTING UPR DYNAMICS/INCOMING DRY AIR...AND 00Z RUC FCST DEEPER MSTR...XPCT SCT SHRA OVER THE CWA THIS EVNG TO END OVER ALL BUT THE ERN ZNS DURING THE NGT. SINCE FLOW ALF IS SW... THINK BULK OF DRY AIR OBSVD IN MN WL REMAIN NW OF CWA. SO EVEN AFTER RA ENDS...WL CALL FOR LINGERING PTCHY FOG/DZ WITH SHALLOW COOL AIR UNDERCUTTING WARMER AIR STREAMING NE IN SW FLOW ALF. TEMPS WL FALL OFF NO MORE THAN A FEW DEGREES OVER THE W WITH BULK OF DRY AIR STAYING TO THE NW. BUT MORE NW FLOW FOLLOWING DEPARTURE OF SHRTWV TO THE N WL CAUSE TEMPS OVER THE WARMER SE ZNS TO FALL WELL INTO THE 40S. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 344 PM EDT THU MAY 13 2004 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE THUNDERSTORM POTENTIAL FOR TONIGHT AND FRIDAY. WATER VAPOR AND RUC/ETA IMAGERY SHOWING A LONGWAVE TROUGH OVER CENTRAL NORTH AMERICA. A COUPLET OF LOW PRESSURE CELLS ARE OVER CENTRAL CANADA. A NUMBER OF WEAK SHORTWAVE ARE BEING EJECTED OUT OF THE BASE OF THIS TROUGH. ONE IS MOVING INTO THE FORECAST AREA...FOLLOWED BY A SHORTWAVE OVER WESTERN IOWA...AND YET ANOTHER OVER KANSAS AND NEBRASKA. SURFACE ANALYSIS DEPICTS A LOW OVER SOUTHEAST ONTARIO WITH A COLD FRONT DRAPED SOUTHWEST INTO CENTAL ILLINOIS. BEHIND THIS FRONT IS A 1027MB HIGH SPREADING INTO THE NORTHERN PLAINS. LIGHT RAIN AND SCATTERED RAINSHOWERS ARE OVER NORTHERN AND CENTRAL WISCONSIN. THE SHORTWAVE PRODUCING SHOWERS OVER WISCONSIN WILL SLIDE ACROSS THE FORECAST AREA TONIGHT AND FRIDAY USHERING IN RAIN TO THE FORECAST AREA. LIFTED INDEX WITH THESE WILL BE AROUND 20 OVERNIGHT. AND CAPE IS ZERO. THUS DO NOT EXPECT ANY THUNDER WITH THIS SYSTEM AS IT MOVES THROUGH. THERE WILL CONSIDERABLE AMOUNT OF MOISTURE OVER THE FORECAST AREA. THE SHORTWAVE ENERGY WILL MOVE ACROSS THE AREA ON FRIDAY. WILL KEEP A MENTION OF SHOWERS IN DISSIPATING FROM THE WEST. A SHORTWAVE WILL SAIL OVER LAKE SUPERIOR FRIDAY EVENING. A HIGH PRESSURE CENTER WILL SPREAD INTO THE UPPER GREAT LAKES BRING DRY STABLE AIR TO THE AREA. AS THE HIGH MOVES OVER THE UPPER GREAT LAKES ON SATURDAY...A SHORTWAVE WILL MOVE THROUGH THE AREA. ETA/GFS INDICATE THAT THE AIR MASS WILL BE VERY DRY. THUS WILL KEEP CONDITIONS DRY THROUGH SATURDAY. MODELS IN FAIRLY GOOD AGREEMENT IN SHOWING TWO CLOSED LOW EMBEDDED IN A LONGWAVE TROUGH OVER NORTHEAST CANADA. GFS/GEM/ECMWF SHOWING A TROUGH SWINGING INTO SOUTHERN MANITOBA BY 12Z SUNDAY. ETA IS THE ODD ONE OUT AS IT DEVELOPS A CLOSED LOW OVER NORTHERN ONTARIO...AND IS MUCH FASTER. PREFER TO STICK WITH THE CONSENSUS. ON SUNDAY THE SHORTWAVE OVER MANITOBA WILL MOVE INTO CENTRAL ONTARIO...WHILE A WEAKER SHORTWAVE MOVES OUT THE NORTHERN PLAINS INTO THE UPPER GREAT LAKES. MEANWHILE...A COLD FRONT WILL SHIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY. ON SUNDAY NIGHT A COLD FRONT WILL MOVE INTO THE WESTERN U.P. AND SHORTWAVE ENERGY WILL SWING THROUGH THE FORECAST AREA. THUS SHOWERS WILL BE MOVING THROUGH ON SUNDAY AND SUNDAY EVENING. A HIGH PRESSURE CENTER WILL FOLLOW ON MONDAY NIGHT BRINGING DRIER AIR INTO THE REGION. ANOTHER SHORTWAVE IS EXPECTED TO MOVE THROUGH THE REGION ON TUESDAY...BUT THE DRIER CONDITIONS SHOULD LIMIT PRECIPITATION. ANOTHER SHORTWAVE WILL RACE ACROSS THE NORTHWEST CONUS AND INTO THE FORECAST AREA BY LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. A SHORTWAVE AND A COLD FRONT WILL SHIFT ACROSS THE FORECAST AREA ON THURSDAY. THESE SHOULD GENERATE MORE SHOWERS AND THUNDERSTORMS. SCATTERED SHOWERS SHOULD PERSIST THROUGH THURSDAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1105 AM EDT THU MAY 13 2004 .DISCUSSION... MAIN FCST CONCERNS THIS AFTERNOON ARE PCPN TRENDS AND TSRA CHANCES. WV IMAGERY AND RUC ANALYSIS INDICATED SW MID/UPR LVL FLOW FROM THE SRN PLAINS TO THE WRN LAKES BTWN ROCKIES TROF AND A RDG OVER THE ERN CONUS. A SHRTWV OVER IA AND UPR LVL DIV WITH RIGHT ENTRANCE OF H25 JET FROM THE ERN DAKOTAS INTO WRN ONTARIO SUPPORTED AN AREA OF SHRA/TSRA OVER SE MN AND WRN WI. AT THE SFC...A STATIONARY FRONT EXTENDED FROM ERN UPR MI TO CNTRL WI AND ERN IA. LOW LVL CONV ALONG AND NORTH OF THE FRONT ALONG WITH PLENTIFUL LOW LVL MOISTURE BLO 850 MB...PER 12Z GRB SNDG...HAS BROUGHT AREAS OF -DZ TO CNTRL UPR MI AND NRN WI. EXTRAPOLATION OF RADAR AND SATELLITE TRENDS AND ETA/RUC SUGGEST SHRA/TSRA SHOULD AFFECT MAINLY THE WEST THIRD OF UPR MI THIS AFTERNOON...WITH AREA IN ALSO IN CLOSEST PROXIMITY TO BEST DPVA FROM THE SHRTWV LIFTING NNE. MUCH OF THE EAST SHOULD ESCAPE THE MORE SIGNFICANT PCPN AS SCT ISOLD PCPN WOULD ARRIVE LATE...MAINLY AFT 20Z. WHILE RUC 1000-700 MUCAPE OF 200-400 J/KG REMAINS MAINLY SOUTH OF UPR MI...SOME ISOLD ELEVATED TSRA CANNOT BE RULED OUT GIVEN LIGHTNING TRENDS WITH PCPN SHIELD LIFTING TO THE NORTH. WHILE RADAR HAS SHOWN WEAKENING RETURNS NEAR KMQT...EXPECT SOME -DZ TO CONTINUE WITH LOW LVL MOISTURE IN PLACE AND CONTINUED UPSLOPE FLOW WITH NNE WINDS. OVER N UPR MI...TEMPS HAVE FALLEN FROM EARLY HIGHS AND SHOULD REMAIN IN THE UPPER 40S FOR THE REST OF THE DAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE ALBANY NY 635 AM EDT THU MAY 13 2004 .DISC...A VERY WEAK SHORT WAVE...IDENTIFIED BY THE RUC40 AND 06Z ETA...OVER NORTHERN NY...IS ENOUGH TO ALREADY TOUCH OFF SOME SHOWER AND THUNDERSTORM ACTIVITY ABOUT TO ENTER THE NW PORTION OF OUR CWA. WHILE THE VORT MAX LOOKS AS IF IT WILL WEAKEN...BOTH MODELS SPREAD QPF (NOT ALL THAT LIGHT) ACROSS MUCH OF THE REGION. WHILE THIS WILL PROBABLY NOT HAPPEN...THIS FIRST BATCH OF CONVECTION WILL SET UP OUTFLOW BOUNDARIES THAT WILL COULD FOCUS LATER CONVECTION. WILL UPDATE THE EARLY MORNING PERIOD AND MENTION AT LEAST THE SLIGHT CHANCE OF SHOWERS AND STORMS OVER OUR CWA...WITH THE HIGHEST POPS IN THE MOHAWK VALLEY. NO CHANGES TO LATER PERIODS INCLUDING TODAY. .ALY...NONE. _____________________________________________________________________ *************PREVIOUS FORECAST DISCUSSION************************** PRODUCTS OUT SHORTLY. .DISC...OVERALL THE "BIG PICTURE" HAS NOT CHANGED MUCH IN THE PAST COUPLE OF DAYS...WITH A LARGE TROUGH IN THE WEST AND A RIDGE IN THE EAST. EVENTUALLY...A PIECE OF THIS TROUGH WILL TRANSLATE EAST AND LEAST TEMPORARILY FLATTEN THE RIDGE AS WE HEAD THROUGH THE WEEKEND. .SHORT TERM...A BACK DOOR COLD FRONT IS LURKING JUST NE OF OUR ZONES THIS MORNING AND IS SLOWLY MOVING SW. HIGH PRESSURE...CENTERED TO THE SE OF HUDSON BAY IS ALSO MOVING SE BUT 3-HR PRESSURE RISES ARE NOT ALL THAT IMPRESSIVE. WILL FOLLOW THE ETA'S SOLUTION WHERE THE BACK DOOR (EVENTUALLY BECOMING SIDE DOOR) FRONT ENDS UP STALLING...WHICH APPEARS TO BE THE HOUSATONIC VALLEY BASIN. A 50 MILE SHIFT (ESPECIALLY WEST) OF THIS POSITION TODAY COULD SIGNIFICANTLY IMPACT HIGH TEMPERATURES. THIS BACK DOOR FRONT WILL SERVE AS THE FOCUSING FOR CONVECTION TO FIRE UP TODAY IN ADDITION TO ANY LEFTOVER OUTFLOW BOUNDARIES LEFT BEHIND BY YESTERDAY'S BRIEF CONVECTIVE OUTBREAK. THERE IS A STEEP GRADIENT OF INSTABILITY DECLINE AS ONE HEADS FROM KALB (FORECASTED TO CREST AT 1800 J/KG THIS AFTERNOON) TO NEARLY 0 ON THE EASTERN BORDER OF OUR CWA. MAGLENTA TODAY GAVE ME VALUES BETWEEN 2.6 AND 3.0 RIGHT AT KALB WHICH MEANS IF ANY CONVECTION WERE TO BREAK OUT...A CELL OR TWO COULD BRIEFLY PULSE TO SEVERE LIMITS WITH BRIEF WIND GUSTS OR MARGINALLY LARGE HAIL. THE WIND FIELD THOUGH FAIRLY WEAK...TURNS ENOUGH FROM A SSE DIRECTION TO WSW WITH HEIGHT TO PRODUCE MODEST SHEAR. STILL...SPC AND MYSELF BOTH AGREE ANY THREAT OF SEVERE TODAY IS NOT BE ENOUGH TO ISSUE ANY KIND OF OUTLOOK. ANY CONVECTION SHOULD DIE DOWN SHORTLY AFTER SUNSET (AS IT HAS MOST NIGHTS). AFTER SUNDOWN...STRATUS ASSOCIATED WITH A SSE FLOW THE PRESUMABLY STALLED OUT BACK/SIDE DOOR FRONT COULD MAKE A MOVE UP INTO AT LEAST THE HUDSON VALLEY. WILL PLAY IT IN THAT DIRECTION...BUT STILL MENTION PATCHY FOG AS WELL. USED THE MET NOS. ON FRIDAY...WHAT'S LEFT OF THE FRONT SHOULD EVENTUALLY PUSH EAST...OR JUST WASHOUT COMPLETELY. WHILE THE MODEL CLOUDS FIELDS LOOK TOO PESSIMISTIC...THE LOWS CLOUDS...SOME FOG AND HAZE MIGHT HOLD TEMPS BACK ENOUGH TO KEEP THEM FROM REACHING FULL POTENTIAL MIXING. FOR NOW...WILL GO CLOSE TO WHAT WAS ALREADY IN THE FIELDS...WHICH IS SLIGHTLY THAN THE LATEST MOS GUIDANCE. ONCE AGAIN...FOCUSING MECHANISMS ON FRIDAY LOOK DIFFICULT (AT BEST) TO FIND...BUT WILL GO WITH A GENERIC 30 AFTERNOON POP. .LONG TERM...IT APPEARS THAT THE NEXT MORE SIGNIFICANT COLD FRONT WILL BEGIN TO SLOWLY PRESS NW-SE ACROSS THE CWA LATER ON SATURDAY. HAVE UP THE ANTE ON POPS TO 50...NOT READY TO LIKELY AS THERE IS STILL SOME DOUBT ON WHEN THE BEST SURFACE CONVERGENCE WILL TAKE PLACE TO TRIGGER LIFT AND CONVECTION. THE GFS HAS THIS FRONT SLIPPING SAFELY TO OUR SOUTH AND EAST BY SUNDAY. THE ETA IS A LITTLE SLOWER. THE CANADIAN REGIONAL MODEL PAINTS A MUCH DIFFERENT PICTURE FOR SUNDAY...WITH SURFACE HIGH BUILDING TO OUR NE AND PRODUCING AN IMPRESSIVE EASTERLY FLOW ALONG WITH RAIN...DESPITE THE LACK OF ANY WAVE (LET ALONE A CLOSED SURFACE CYCLONE) ALONG THE STALLED OUT FRONT. GIVEN ITS TRACK RECORD DURING THE PAST SEVERAL MONTHS...I HAVE ENTIRELY DISMISSED ITS SOLUTION AND WILL GO WITH CONSISTENCY AND THE LATEST GFS OFFERING. HAVE LEFT THE REST OF THE EXTENDED ALONE AS WELL. .AVIATION... CLEAR TO PARTLY CLOUDY SKIES. HIGH LOW LEVEL MOISTURE AND LIGHT WINDS HAVE LEAD TO THE FORMATION OF FOG. MVFR TO IFR WITH LOCALLY LIFR. FOGGY CONDITIONS WILL IMPROVE AFTER SUNRISE. BY MID MORNING NO RESTRICTIONS EXPECTED. WITH BOUNDARY JUST TO EAST AND UNSTABLE AIRMASS IN PLACE HAVE PLACED VICINITY THUNDERSTORMS AT TAFS SITES THROUGH AFTERNOON INTO EVENING HOURS. WILL BE HARD TO PINPOINT WHERE CONVECTION WILL DEVELOP. WINDS ALOFT FAIRLY LIGHT SO WILL BE SLOW MOVERS PRODUCING HEAVY DOWNPOURS. TONIGHT FOG WILL FORM AGAIN AND WILL BE WORSE THAN THIS MORNING ESPECIALLY WHERE IT RAINS AND STRATUS WILL FORM IFR-LIFR CONDITIONS. .HYDROLOGY...STILL NO MAJOR PROBLEMS ANTICIPATED AS ANY AVERAGE RIVER BASIN QPF GENERATED BY CONVECTION TODAY AND TOMORROW WILL BE WELL BELOW FFG VALUES. THAT BEING SAID...WITH PW VALUES OF 1.5...AND ANY STORMS MOVING FAIRLY SLOWLY TODAY OR TOMORROW...SOME VERY LOCALIZED AREAS COULD RECEIVE HEFTY RAINFALL AMOUNTS...ENOUGH TO CAUSE BRIEF RISES IN SMALL STREAMS AND PONDING OF WATER. BY SATURDAY...THE POTENTIAL FOR MORE WIDESPREAD RAINFALL IS THERE. AT THIS POINT...IT APPEARS THAT AVERAGE RIVER BASIN QPF SHOULD STILL FALL BELOW FFG VALUES...BUT ANY TRAINING OR BACKBUILDING CELLS COULD CAUSE LOCALIZED FLASH FLOODING. .ALY...NONE. $$ HWJIV/IAA ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1015 AM EDT THU MAY 13 2004 .DISCUSSION... SHOWERS AND THUNDERSTORMS BREAKING OUT ALONG THE RESIDUAL BOUNDARIES FROM YESTERDAY'S CONVECTION. MORNING SOUNDINGS INDICATE MODELS ARE ON THE RIGHT TRACK IN DRYING THINGS OUT. MAY ACTUALLY BE LESS CONVECTION AROUND MID TO LATE AFTERNOON AS SUBSIDENCE IS EXPECTED TO INCREASE WITH REBUILDING RIDGE AND ARRIVAL OF DRIER AIR IN THE MID LEVELS. INCREASED POPS TO 30 PERCENT AREA WIDE FOR THIS AFTERNOON. TWEAKED TEMPS UP AND DEWPOINTS DOWN FOR THE AFTERNOON. && .MARINE... WINDS AT 41013 CONTINUE TO BE FROM THE SOUTH AT 10 MPH WITH SEAS VARYING BETWEEN 2.6 AND 3 FT. LATEST RUC FORECAST SHOWING WINDS CONTINUING FROM THE SOUTH AT 10 KNOTS FOR THE REMAINDER OF THE DAY. A BOUNDARY FROM YESTERDAYS CONVECTION FROM NEAR MYR TO DPL. EVEN WITH LITTLE UPPER LEVEL SUPPORT AND SLIGHTLY DRIER ATMOSPHERE TODAY WILL INTRODUCE SCATTERED SHOWERS OVER COASTAL WATERS. && .PRELIMINARY POINT TEMPS/POPS... WILMINGTON 85 66 83 66 / 30 10 10 10 FLORENCE 86 64 85 64 / 30 20 20 20 LUMBERTON 86 64 85 64 / 30 20 20 20 MYRTLE BEACH 81 69 80 69 / 30 10 10 10 && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. && $$ PUBLIC: RJD MARINE: HAWKINS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 920 PM EDT THU MAY 13 2004 .DISCUSSION... AN AREA OF VORTICITY IN THE MID LVLS WAS NOTED ON THE LATEST RUC 40 KM...WHICH STRETCHED FROM ERN MI...SOUTHWARD...INTO N CNTRL KY. THIS FEATURE IS FCST TO MOVE NE OVERNIGHT...WEAKENING AS IT DOES. LATEST KILN RADAR WAS STILL SHOWING AN AREA OF SHOWERS ACRS SOUTH CENTRAL AND CENTRAL OHIO...MOVING NE. AM EXPECTING THESE SHOWERS TO EVENTUALLY DIE OUT AROUND MIDNIGHT OR SO AS WEAK LOW LVL FORCING AT 850 MB DISSIPATES. AS A RESULT...AM NOT EXPECTING MUCH IN THE WAY OF PCPN AFTER MIDNIGHT. WITH RECENT RAINS...AND SOME HOLES IN THE CLOUD DECK...COULD SEE SOME PATCHY FOG...AND MAY VERY WELL EMPLOY THIS IN THE ZONES. OTHERWISE...CURRENT FCST LOWS ARE IN THE BALL PARK...AND ONLY MINOR TWEAKS ARE ANTICIPATED. && .ILN WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. OH...NONE. && $$ oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 910 PM EDT THU MAY 13 2004 .UPDATE... RADAR SHOWING SEVERAL SMALL SHOWERS REGENERATING IN THE UPSLOPE AREAS ATTM. VERY LITTLE HAS CHANGED SINCE LAST NIGHT AND AGAIN UPSLOPE SHOWERS ARE EXPECTED OVERNIGHT. RUC AND ETA CONTINUE TO SHOW CAPE OF 2-5 HUNDRED J/KG REMAINING...WITH GENERAL SE LLVL FLOW AND SMALL VORTS SHOULD SUPPORT SCATTERED SHOWERS...POSSIBLY A TS. WILL PROLONG CHC OVERNIGHT FOR THE HIGHER TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY. WITH LLVL MOISTURE REMAINING HIGH WILL INTRODUCE AREAS OF FOG. TEMPS TREND AND MINS LOOK GOOD...INCREASED DWPTS A FEW DEGREES. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ NED sc AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 834 PM CDT THU MAY 13 2004 .DISCUSSION... NO BIG CHANGES EXPECTED FOR THE OVERNIGHT HOURS. PRECIPITATION COVERAGE A LITTLE MORE THAN EXPECTED...BUT WITH LIGHT PRECIPITATION AMOUNTS...JUST COVERED WITH NOWCASTS AND CHANGED THE TIMING IN THE GRIDS A BIT. LOOKS LIKE SHOWERS DEVELOPED IN AN AREA OF 700MB FORCING...WHICH QUICKLY EXITS THE AREA AFTER 06Z. SOME 600MB FRONTOGENESIS LINGERS THROUGH ABOUT 09Z...SO WILL LEAVE A SLIGHT CHANCE FAR SOUTHEAST THROUGH ABOUT THEN...THEN TAKE OUT EVERYTHING AFTER 09Z. ONE CONCERN ABOUT FROST ADVISORY OVER WESTERN CWA IS CLOUD COVER OVER THE NORTH. WITH SUN GOING DOWN...CLOUDS ARE NOT BREAKING UP...SO THE CLOUDS MAY HAVE MORE TO THEM THAN JUST A DIURNAL KICK FROM THE SUN. IF THEY DO CONTINUE TO HOLD TOGETHER...WOULD NEED TO BOOST LOWS UP A BIT...CLOSER TO THE LATEST RUC AND ETA OUTPUT...WITH LOWS RANGING FROM THE MID 30S NORTHWEST TO THE LOW TO MID 40S FAR SOUTHEAST. && .FSD...WATCHES/WARNINGS/ADVISORIES... SD...FROST ADVISORY LATE TONIGHT ZONES SDZ038>040-050-052>070. MN...NONE. IA...NONE. NE...NONE. && $$ 08 sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 1030 AM CDT THU MAY 13 2004 .DISCUSSION... BAND OF NUMEROUS SHOWERS NOW OVER EASTERN MIDDLE TENNESSEE, WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING WEST OF THAT AREA. BY LATE MORNING SKIES WERE STILL CLOUDY AREA-WIDE, WITH TEMPERATURES MAINLY AROUND 70 DEGREES. EXPECT BAND OF MAX PRECIPITATION EFFICIENCY TO CONTINUE MOVING SLOWLY EASTWARD THIS AFTERNOON, LEAVING MOST OF THE MID STATE IN AN ENVIRONMENT CONDUCIVE TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. THIS IS SUPPORTED BY LATEST RUC PRECIPITATION PROJECTIONS. THUS, WILL UPDATE TO LOWER POPS A LITTLE (INTO THE CHANCE CATEGORY)FOR AREAS WEST OF THE PLATEAU THIS AFTERNOON. OTHERWISE, LITTLE CHANGE TO PREVIOUS ZONE PACKAGE. && .BNA WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 19 tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 635 PM CDT THU MAY 13 2004 .1ST PD...CURRENT STLT PICS SHOW CONVECTION ALONG THE LEE SIDE OF THE SIERRA MADRE ORIENTALS...WITH SHRAS/TSRAS IN TX CONFINED TO POINTS N AND NE OF CRP...WHERE TOR #201 AND #199 ARE CURRENTLY IN EFFECT. MSAS SFC ANALYSIS SHOWS NOSE OF CF HAS DIPPED SOUTH TO BETWEEN KSJT AND KDYX WITH THE DRYLINE TROF EXTENDING FM NEAR KSWW SOUTH TO JUST NW OF KDRT. MSTR IS CONFINED TO THE WARM SECTOR...EAST OF THE DRYLINE TROF. DWPTS IN KALI ARE 77 DEG F...WITH UPPER 70 DWPTS IN PLACE SOUTH OF KALI TO KBRO. MSAS SFC COMPUTED LI'S ARE -10 TO -11 OVR RGV NOW...>-14 JUST WEST OF ZAPATA IN ADJ OLE MEX. RUC80 SHOWS CONVECTION DECREASING TO OUR N AND NE BY 03Z WITH NO RECOGNITION OF THE CONVECTION THAT IS ENTRENCHED NOW JUST WEST OF ZAPATA OR THE INTENSITY OF CONVECTION N AND NW OF KCRP. WILL DISREGARD RUC SUGGESTION OF A DRY EVENING IN THE RGV AND SKEW TO MESOETA SOLUTION...WHICH RECOGNIZES THE REAL POSSIBILITY OF OUTFLOWS INITIATING SUM CONVECTION OVR OUR CWF THIS EVENING. (ALTHOUGH THE MDL DOE NOT RECOGNIZE THE VOLATILITY OF OUR ATM ATTM) CRP TOR SHOWS MORE FAVORABLE ENVIRONMENT WHEN FORCING COMES SOUTH...AS THIS AREA IS THE SOUTHERN-MOST EDGE OF LARGE CONVECTIVE COMPLEX EXTENDING FM JUST NW OF KCRP INTO ERN TX AND LA ATTM. CONVECTION CONTINUES TO INCREASE IN AERIAL COVERAGE AND INTENSITY OVR ADJ OLE MEX...ABOUT 70 MILES W AND SW OF THE CITY OF ZAPATA. THESE STORMS SHOW A MORE EAST AND SOUTHEAST MVMT AND IMPLY ADVECTION TO THE RGV LATER THIS EVENING OR OVRNGT. THE CONVECTION NEAR CRP AND POINTS N AND NW IS MVG NE AT 15 MPH. CI VEIL FM OLE MEX CONVECTION NOW OVR WRN VLY AND BELIEVE OUTFLOWS FM SVR WX NEAR CRP WILL HAVE AN IMPACT ON OUR NRN COASTAL WATERS IN THE FORM OF TSTM DEVELOPMENT OR STRONG WND SHIFT. WILL BUMP POPS A CAT AND ADD HVY RAFL TO 1ST PD ATTM. && PREVIOUS DISCUSSION FOLLOWS: .SHORT TERM...LULL IN ACTIVITY FOR THE TIME BEING AS AM H5 VORT DEPARTS NE. UPSTREAM H5 VORT STILL VISIBLE IN SAT IMAGERY AND WILL GIVE IT EXTRA WEIGHT IN FRI FCSTS BASED UPON ABSENCE OF MX SOUNDINGS IN AM MODEL RUNS. COMBO OF APPROACHING BNDRY AND PVA FROM THIS FEATURE CALLS FOR GOING ABOVE MOS CONSENSUS FOR POPS FRI AND SAT. WILL GO A TAD ON THE SLOW SIDE FOR BRINGING QPF INTO THE CWA AS GFS HAS TRENDED A BIT SLOWER WITH THE BNDRY. MODELS SEEM TO HAVE CONVERGED ON SOLUTION BRINGING BNDRY INTO THE CWA...THEN STALLING IT. BNDRY WILL WASH OUT SUN...BUT WILL STILL PROVIDE AT LEAST A DIFFUSE FOCUS FOR DIURNALLY DRIVEN CONVECTION. BEST CHANCES WILL BE NEAR THE SEA BREEZE CONVERGENCE. WILL NOT DEVIATE FAR FROM MOS CONSENSUS FOR TEMPS...WHICH DROP A BIT FRI NITE/SAT NITE AS DRIER AIR ARRIVES VIA CONVECTIVE OUTFLOWS/DYING POLAR BNDRY. && .LONG TERM...SLIGHT CHANCE POPS LOOK TO BE IN THE OFFING MON AND TUE FOR DIURNAL SHRA/TSRA BEGINNING ALONG THE SEA BREEZE CONVERGENCE AND MOVING INLAND. GULF MOISTURE BELOW H7 WILL BE SUPPLEMENTED BY PAC MOISTURE ABOVE. WED AND THU LOOK A BIT DRY AND BREEZY TO WINDY AS GFS DEEPENS SRN PLAINS LOW PRESSURE. INCREASING SHEAR BELOW H7 WILL INHIBIT SEA BREEZE CONVECTION DURING THIS TIME FRAME. && .MARINE...BUOY 020 REPORTS SOUTHEAST WINDS AROUND 20 KNOTS WITH 8 FEET SEAS. WILL HAVE SMALL CRAFT ADVISORY FOR BOTH THE LAGUNA AND THE GULF FOR TONIGHT AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO LOW PRESSURE MOVING ACROSS THE GREAT PLAINS. ALSO...XPCT OUTFLOWS AND TSTM DEVELOPMENT OVR MAINLY NORTHERN AREAS. THESE CONDITIONS WILL PERSIST THROUGH FRI...AS A COLD FRONT APPROACHES FROM THE NORTHWEST. AS A RESULT OF THE FRONT...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE FROM FRIDAY THROUGH SUNDAY...WITH WINDS BACKING TO THE EAST. BY MONDAY WINDS WILL RETURN TO MODERATE SOUTHEAST. && .AVIATION...IFR CIGS POSSIBLE FOR MFE DURING EARLY MRNG FM +TSRA AND VSBYS. MVFR OVR MAJORITY OF RGV TNGT...THEN CIGS 1500 FT POSSIBLE DURING FRI PM +TSRA WITH STRONG AND GUSTY WINDS NEAR CONVECTION. OTHERWISE...MODERATE SOUTHEAST WINDS WILL PERSIST FOR THE NEXT 24 HOURS. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 78 85 73 83 71 / 20 20 30 40 20 BROWNSVILLE 78 87 72 85 70 / 20 20 30 50 20 HARLINGEN 77 89 70 86 69 / 20 20 30 50 20 MCALLEN 77 90 71 85 71 / 20 30 40 60 30 RIO GRANDE CITY 76 90 70 85 70 / 30 40 50 60 30 SOUTH PADRE ISLAND 77 83 73 81 72 / 20 20 30 40 20 && .BRO WATCHES/WARNINGS/ADVISORIES...SCA FOR GMZ130-150-155-170-175. && $$ SYNOPTIC/GRIDS/AVIATION/MARINE...58 MESO...MARTINEZ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 315 PM CDT THU MAY 13 2004 ...TORNADO WATCH IN EFFECT FOR PORTIONS OF THE VICTORIA CROSSROADS AND RIO GRANDE PLAINS... WILL SEND OUT NEW ZONES TO HEADLINE TORNADO WATCH FOR THE NORTHERN TIER COUNTIES FROM LA SALLE TO VICTORIA THROUGH 8 PM. VERY MOIST AND UNSTABLE ATMOSPHERE...WITH CAPES AROUND 4000 J/KG...REMAINS IN PLACE ACROSS THE REGION. SURFACE TROUGH EXTENDING FROM NORTHEAST MEXICO INTO THE GULF OF MEXICO HAS HELPED TO BACK WINDS CONSIDERABLY OVER THE VICTORIA CROSSROADS AND NORTHERN COASTAL BEND THIS AFTERNOON CREATING AT LEAST A MODERATELY SHEARED ENVIRONMENT. ANALYSIS FROM LAPS DATA CONTIUES TO SHOW 0-3 KM HELICITY VALUES AROUND 100. && .PREVIOUS DISCUSSION... .SHORT-TERM (TONIGHT THROUGH FRIDAY NIGHT)...INTERESTING FORECAST BEGINNING TONIGHT. RADAR IS BECOMING MORE ACTIVE THIS AFTERNOON AS SHOWERS AND THUNDERSTORMS TRY TO DEVELOP ALONG THE I-35 CORRIDOR. RUC AND MESO-ETA MODEL SOUNDINGS ARE INDICATING CAPE VALUES OF 4000 J/KG ACROSS CWA WITH SURFACE TEMPS IN THE LOW TO MID 80S. DECENT SHEAR IS IN PLACE ACROSS THE EASTERN HALF AS WELL WITH THE REMNANTS OF THE LLJ KEEPING 25 KNOT WINDS AT 1-2 KFT. CURRENT SATELLITE AND RADAR TRENDS ARE SHOWING DEEPENING CONVECTION ALONG THE COLD FRONT AND DRYLINE TO OUR NORTH...WITH ONLY LIGHT TO MODERATE SHOWERS IN OUR CWA. THINK THIS TREND WILL CONTINUE THIS AFTERNOON...WITH THUNDER DEVELOPING IN THE INLAND SECTIONS OF SOUTH TEXAS...AS INSTABILITY REMAINS A NON-ISSUE. WILL GO WITH THE HIGHEST POPS ACROSS THE NORTHERN TIER COUNTIES BUT WILL KEEP AT LEAST CHANCE POPS ACROSS THE ENTIRE AREA. WINDS SHOULD REMAIN AROUND 10-15 KNOTS OVERNIGHT...WITH 15-20 OVER THE WATERS. WILL CONTINUE SCA FOR THE GULF WATERS AS LLJ INTENSIFIES AGAIN TONIGHT. SCEC LOOKS REASONABLE FOR THE GULF. MAIN FORECAST PROBLEM WILL BE A TIMING ISSUE WITH THE FRONT AND ASSOCIATED CONVECTION. CURRENT THINKING IS THAT WITH STORMS FIRING ALONG THE FRONT...BOUNDARY COULD ACCELERATE A LITTLE MORE THAN FORECAST AND CONVECTION COULD REACH THE NORTH BEFORE 12Z. WILL GO CLOSER TO THE GFS TIMING AND BRING LIKELY POPS INTO THE FORECAST AROUND 14Z FRIDAY AND SPREADING SOUTH THROUGHOUT THE MORNING. MODEL DISCREPANCIES CONTINUE WITH HOW THE FEATURE IS BEING HANDLED FROM THIS POINT ON. ETA IS BLOWING AN MCS THROUGH SOUTH TEXAS DURING THE MORNING/EARLY AFTERNOON AND CLEARING OUT. GFS IS STALLING THE BOUNDARY OVER THE CWA AND KEEPING CHANCE POPS IN THE FORECAST THROUGH THE WEEKEND. NGM IS KEEPING THE FRONT TO THE NORTH. UKMET IS SIMILAR TO THE GFS IN STALLING THE BOUNDARY ACROSS SOUTH TEXAS. WILL LEAN TOWARDS THE GFS AND UKMET SOLUTIONS AND KEEP LOW-END CHANCE POPS IN THE FORECAST THROUGH FRIDAY NIGHT. && LONG-TERM (SATURDAY THROUGH THURSDAY)...A COLD FRONT WILL WEAKLY STALL ACROSS THE CWA SATURDAY MORNING THEN QUICKLY DISSIPATE AND/OR RE-POSITION NORTH OF THE REGION WITH A WEAK TO MODERATE ONSHORE FLOW PREVAILING THROUGH SUNDAY NIGHT. PWAT DISPARITIES BETWEEN THE GFS/ETA IS A FUNCTION OF MID/UPPER TROPOSPHERIC MOISTURE. LOWER TROPOSPHERIC MOISTURE DEPTH IS SUFFICIENTLY DEEP PER BOTH MODELS WITH ADEQUATE INSTABILITY. THE ONLY FORCING MECHANISM FOR CONVECTION IS THE SEA BREEZE BOUNDARY AND THAT IS NOT IMPRESSIVE. MACROSCALE SUBSIDENCE IN THE WAKE OF AN MCS WILL PLAY A HINDERING ROLE SATURDAY WHILE A DEVELOPING MID TROPOSPHERIC SUBSIDENCE INVERSION PLAYS A COUNTERACTING PART SUNDAY. WILL ONLY INDICATE SLIGHT CHANCE POPS FOR DIURNAL CONVECTION. PATCHY/AREAS OF OVERNIGHT/MORNING FOG PROBABLE GIVEN A DECOUPLED BOUNDARY LAYER AND BREAKS IN THE CLOUDS. GUIDANCE TEMPERATURES WERE QUITE REASONABLE AND WERE FOLLOWED CLOSELY. A WEAKNESS ALOFT WITH VORTICITY MAXIMA CIRCULATING AROUND IT WILL PERSIST MONDAY THROUGH WEDNESDAY BEFORE EXITING THURSDAY AND ALLOWING UPPER-LEVEL RIDGING TO TAKE HOLD. ONSHORE FLOW AT THE SURFACE WILL CONTINUE AND SUSPECT THAT PWATS WILL BE HIGHER GIVEN THE UPPER-LEVEL FEATURE. WILL INDICATE SLIGHT CHANCE POPS FOR MONDAY THROUGH WEDNESDAY DUE TO WEAK UPPER-LEVEL FORCING AND DIURNAL SURFACE FORCING ALONG THE SEA BREEZE BOUNDARY. TEMPERATURES WITHIN A DEGREE OR TWO OF CLIMATOLOGY AND TYPICAL DIURNAL TRENDS IN CLOUDINESS CAN BE EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 74 82 68 82 68 / 30 60 40 20 10 VICTORIA 72 81 65 81 68 / 40 60 40 20 10 LAREDO 76 87 69 87 70 / 30 50 40 20 10 ALICE 73 85 67 85 67 / 30 60 40 20 10 ROCKPORT 75 83 70 83 71 / 30 60 40 20 10 COTULLA 73 86 65 85 67 / 40 60 40 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES...SCA GMZ250-255-270-275. TORNADO WATCH THROUGH 8 PM FOR VICTORIA...GOLIAD...BEE...LIVE OAK...MCMULLEN AND LA SALLE COUNTIES. && $$ 94/MJ...SHORT-TERM 85/BB...LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 200 PM CDT THU MAY 13 2004 .SHORT-TERM (TONIGHT THROUGH FRIDAY NIGHT)...INTERESTING FORECAST BEGINNING TONIGHT. RADAR IS BECOMING MORE ACTIVE THIS AFTERNOON AS SHOWERS AND THUNDERSTORMS TRY TO DEVELOP ALONG THE I-35 CORRIDOR. RUC AND MESO-ETA MODEL SOUNDINGS ARE INDICATING CAPE VALUES OF 4000 J/KG ACROSS CWA WITH SURFACE TEMPS IN THE LOW TO MID 80S. DECENT SHEAR IS IN PLACE ACROSS THE EASTERN HALF AS WELL WITH THE REMNANTS OF THE LLJ KEEPING 25 KNOT WINDS AT 1-2 KFT. CURRENT SATELLITE AND RADAR TRENDS ARE SHOWING DEEPENING CONVECTION ALONG THE COLD FRONT AND DRYLINE TO OUR NORTH...WITH ONLY LIGHT TO MODERATE SHOWERS IN OUR CWA. THINK THIS TREND WILL CONTINUE THIS AFTERNOON...WITH THUNDER DEVELOPING IN THE INLAND SECTIONS OF SOUTH TEXAS...AS INSTABILITY REMAINS A NON-ISSUE. WILL GO WITH THE HIGHEST POPS ACROSS THE NORTHERN TIER COUNTIES BUT WILL KEEP AT LEAST CHANCE POPS ACROSS THE ENTIRE AREA. WINDS SHOULD REMAIN AROUND 10-15 KNOTS OVERNIGHT...WITH 15-20 OVER THE WATERS. WILL CONTINUE SCA FOR THE GULF WATERS AS LLJ INTENSIFIES AGAIN TONIGHT. SCEC LOOKS REASONABLE FOR THE GULF. MAIN FORECAST PROBLEM WILL BE A TIMING ISSUE WITH THE FRONT AND ASSOCIATED CONVECTION. CURRENT THINKING IS THAT WITH STORMS FIRING ALONG THE FRONT...BOUNDARY COULD ACCELERATE A LITTLE MORE THAN FORECAST AND CONVECTION COULD REACH THE NORTH BEFORE 12Z. WILL GO CLOSER TO THE GFS TIMING AND BRING LIKELY POPS INTO THE FORECAST AROUND 14Z FRIDAY AND SPREADING SOUTH THROUGHOUT THE MORNING. MODEL DISCREPANCIES CONTINUE WITH HOW THE FEATURE IS BEING HANDLED FROM THIS POINT ON. ETA IS BLOWING AN MCS THROUGH SOUTH TEXAS DURING THE MORNING/EARLY AFTERNOON AND CLEARING OUT. GFS IS STALLING THE BOUNDARY OVER THE CWA AND KEEPING CHANCE POPS IN THE FORECAST THROUGH THE WEEKEND. NGM IS KEEPING THE FRONT TO THE NORTH. UKMET IS SIMILAR TO THE GFS IN STALLING THE BOUNDARY ACROSS SOUTH TEXAS. WILL LEAN TOWARDS THE GFS AND UKMET SOLUTIONS AND KEEP LOW-END CHANCE POPS IN THE FORECAST THROUGH FRIDAY NIGHT. && LONG-TERM (SATURDAY THROUGH THURSDAY)...A COLD FRONT WILL WEAKLY STALL ACROSS THE CWA SATURDAY MORNING THEN QUICKLY DISSIPATE AND/OR RE-POSITION NORTH OF THE REGION WITH A WEAK TO MODERATE ONSHORE FLOW PREVAILING THROUGH SUNDAY NIGHT. PWAT DISPARITIES BETWEEN THE GFS/ETA IS A FUNCTION OF MID/UPPER TROPOSPHERIC MOISTURE. LOWER TROPOSPHERIC MOISTURE DEPTH IS SUFFICIENTLY DEEP PER BOTH MODELS WITH ADEQUATE INSTABILITY. THE ONLY FORCING MECHANISM FOR CONVECTION IS THE SEA BREEZE BOUNDARY AND THAT IS NOT IMPRESSIVE. MACROSCALE SUBSIDENCE IN THE WAKE OF AN MCS WILL PLAY A HINDERING ROLE SATURDAY WHILE A DEVELOPING MID TROPOSPHERIC SUBSIDENCE INVERSION PLAYS A COUNTERACTING PART SUNDAY. WILL ONLY INDICATE SLIGHT CHANCE POPS FOR DIURNAL CONVECTION. PATCHY/AREAS OF OVERNIGHT/MORNING FOG PROBABLE GIVEN A DECOUPLED BOUNDARY LAYER AND BREAKS IN THE CLOUDS. GUIDANCE TEMPERATURES WERE QUITE REASONABLE AND WERE FOLLOWED CLOSELY. A WEAKNESS ALOFT WITH VORTICITY MAXIMA CIRCULATING AROUND IT WILL PERSIST MONDAY THROUGH WEDNESDAY BEFORE EXITING THURSDAY AND ALLOWING UPPER-LEVEL RIDGING TO TAKE HOLD. ONSHORE FLOW AT THE SURFACE WILL CONTINUE AND SUSPECT THAT PWATS WILL BE HIGHER GIVEN THE UPPER-LEVEL FEATURE. WILL INDICATE SLIGHT CHANCE POPS FOR MONDAY THROUGH WEDNESDAY DUE TO WEAK UPPER-LEVEL FORCING AND DIURNAL SURFACE FORCING ALONG THE SEA BREEZE BOUNDARY. TEMPERATURES WITHIN A DEGREE OR TWO OF CLIMATOLOGY AND TYPICAL DIURNAL TRENDS IN CLOUDINESS CAN BE EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 74 82 68 82 68 / 30 60 40 20 10 VICTORIA 72 81 65 81 68 / 40 60 40 20 10 LAREDO 76 87 69 87 70 / 30 50 40 20 10 ALICE 73 85 67 85 67 / 30 60 40 20 10 ROCKPORT 75 83 70 83 71 / 30 60 40 20 10 COTULLA 73 86 65 85 67 / 40 60 40 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES...SCA GMZ250-255-270-275. && $$ 94/MJ...SHORT-TERM 85/BB...LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 316 AM CDT FRI MAY 14 2004 .DISCUSSION... SEVERAL QUESTIONS EARLY THIS MORNING. THE NEED TO EXPAND FLOOD WATCH AND TIMING THE END OF THE PRECIPITATION ARE JUST 2 OF THEM. LATEST MSAS ANALYSIS HAS THE MAIN FRONT FROM NEAR RFD TO STL TO NEAR LIT. A PRE-FRONTAL WAVE SHOWS UP WELL ACROSS NORTHEAST ARKANSAS. ADDITIONAL CONVECTION DEVELOPING OVER MOST OF THE CWA AROUND 06Z. FROM 04 TO 05Z CGI REPORTED .74 INCHES OF RAIN. FIRST MAIN RAIN AREA WILL PUSH ACROSS MUCH OF THE CWA THIS MORNING. PRECIPITABLE WATER VALUE ON EVENING RAOB FROM LIT WAS 1.76 INCHES. LOOKING BACK OVER THE PAST COUPLE OF DAYS COOP RAINFALL REPORTS SHOW THAT ONLY SOUTHWEST INDIANA HAD ANY SIGNIFICANT RAINFALL. FLASH FLOOD GUIDANCE VALUES ARE OVER 2 INCHES IN 3 HOURS AND MANY ARE OVER 2 INCHES IN 1 HOUR FOR MANY COUNTIES OUTSIDE OF THE CURRENT WATCH AREA. MUCH OF THE WATCH AREA HAS SEEN AT LEAST 1 TO 2 INCHES OVERNIGHT. SOME COUNTIES REPORTED DITCHES FULL. ANY ADDITIONAL RAINFALL IN THOSE AREAS MAY CAUSE FLOODING. NEW EXCESSIVE RAINFALL DISCUSSION KEEPS THE PROBLEMS SOUTH ALONG THE GULF COAST. AT THIS TIME...DO NOT EXPECT TO EXPAND THE FLOOD WATCH. RADAR TRENDS LATER THIS MORNING WILL NEED TO BE MONITORED CLOSELY. THE FRONT IS PROGGED BY ALL MODELS TO MOVE THROUGH THE CWA DURING THE DAY TODAY...REACHING AN EVV-PAH LINE BY ABOUT 18Z. THE UPPER FLOW WILL PUSH THE NORTHERN SECTION FASTER THAN THE SOUTHERN PORTIONS. LIKE THE SLIGHTLY SLOWER MOVEMENT OF MESOETA. LATEST RUC MODEL IS IN GOOD AGREEMENT. IF REDEVELOPMENT OCCURS ALONG THE FRONT LATER TODAY...SHOWERS AND THUNDERSTORMS WILL RETURN. TIME HEIGHT CROSS SECTIONS SUGGEST JUST THAT. K-INDEX VALUES SUGGEST THAT THERE MAY BE POST FRONTAL THUNDERSTORMS...CURRENT GRIDS LOOK GOOD IN THAT RESPECT. MINOR ADJUSTMENTS MADE FOR TIMING. DID LINGER PRECIPITATION OVER THE SOUTHEAST INTO SATURDAY MORNING. WILL MAKE ADJUSTMENTS TO TEMPERATURES TODAY AS FRONT WILL PASS THROUGH MUCH OF SOUTHEAST MISSOURI AND PORTIONS OF SOUTHERN ILLINOIS BY 15Z. COLD AIR ADVECTION PLUS CLOUDS WILL NOT ALLOW FOR MUCH WARMING IN THOSE AREAS TODAY. ONLY ADJUSTMENTS LATER WERE TO SLIGHTLY INCREASE CLOUD COVER EARLY ON MONDAY. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...FLOOD WATCH TIL 6 PM FRI FOR FULTON COUNTY KY. MO...FLOOD WATCH TIL 6 PM FRI ALL OF SE MO...EXCEPT FOR PERRY COUNTY. IL...NONE. IN...NONE. && $$ SPODEN ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 230 AM CDT THU MAY 13 2004 FORECAST CHALLENGE CONCERNS RAIN CHANCES AND TEMPERATURES. MODELS IN FAIR AGREEMENT THROUGH PERIOD AND WILL USE MIX FOR DETAILS. SURFACE HIGH PRESSURE TO DRIFT ACROSS FA TODAY. 850MB TEMPERATURES MAKE SOME RECOVERY THIS AFTERNOON HOWEVER WITH LACK OF MIXING WILL BE RELYING MAINLY ON SOLAR. GOOD POTENTIAL FOR RECORD LOWS WHICH WILL MAKE FOR COLD START. MVFR CIGS CURRENTLY CONFINED TO AREAS WEST OF RED RIVER AND RUC GRADUALLY DRIES LOWER LEVELS. ELSEWHERE CONVECTIVE TEMPERATURES CLOSE TO MID/LATE AFTERNOON READINGS SO SHOULD SEE PLENTY OF SOLAR. WITH COLD START AND LACK OF MIXING WILL TREND TEMPERATURES ON COOL SIDE OF GUIDANCE VALUES. COLDEST TEMPERATURES WILL BE OVER RESIDUAL SNOW PACK ALONG CANAM BORDER AREA. WARM ADVECTION/RETURN FLOW INCREASES OVERNIGHT. RESPECTABLE CONVERGENCE WITH DEVELOPING LOW LEVEL JET AND WITH STRENGTH OF WARM ADVECTION AND APPROACHING INITIAL WAVE WILL INTRODUCE MINOR POPS FROM VALLEY WEST TOWARDS MORNING. WITH ABOVE WILL SEE MORE REASONABLE MINIMUM TEMPERATURES. STRONGER SHORTWAVE TO TRACK ACROSS NORTHERN FA LATER ON SATURDAY. DEEP MOIST LACKING WITH ETA INDICATING PRECIPITABLE H2O VALUES JUST OVER A HALF INCH HOWEVER CONVERGENCE AND INSTABILITY SUFFICIENT TO KEEP THUNDER GOING. WILL KEEP RAIN CHANCES GOING FOR EASTERN AREAS SUNDAY MORNING. NEXT WAVE ZIPS ACROSS SD SUNDAY WITH MAIN AREA OF RAIN TO OUR SOUTH SO WILL NOT EXPAND POPS HOWEVER BEARS WATCHING. SERIES OF WAVES IN DEVELOPING SW MID LEVEL FLOW INTO MONDAY SO WILL CONTINUE RAIN CHANCES OVER SOUTHERN THIRD OF FA. HIGH PRESSURE FOLLOWS INTO MID WEEK. THIS ALL REFLECTED WELL BY CURRENT FORECAST SO NO CHANGES PLANNED TO LONG RANGE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...RIVER FLOOD WARNING FOR ROSEAU RIVER AT ROSEAU AND TWO RIVERS RIVER AT HALLOCK. AREAL FLOOD WARNING FOR ROSEAU AND MARSHALL COUNTIES UNTIL MID MORNING. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 1058 PM PDT THU MAY 13 2004 .SYNOPSIS...A COOL AND SOMEWHAT UNSTABLE AIRMASS WILL GIVE WAY TO WEAK HIGH PRESSURE RIDGING ON FRIDAY. SHOWERS AND AFTERNOON THUNDERSTORMS WILL LINGER IN THE EXTREME NORTHEASTERN PORTION OF WASHINGTON AND THE NORTHERN IDAHO PANHANDLE ON FRIDAY AFTERNOON. A RAPIDLY MOVING WEATHER SYSTEM THAT WILL TRACK EASTWARD INTO OREGON THIS WEEKEND. THE BULK OF THE PRECIPITATION WILL BE CONFINED TO OREGON. && .DISCUSSION... REST OF TONIGHT...THE SHOWERS AND THUNDERSTORMS FROM EARLIER TODAY HAVE WITHERED AWAY TO NOTHING EXPECT FOR A SMALL BATCH OF SHOWERS EXTENDING FROM WENATCHEE TO OTHELLO. THESE SHOWERS SEEM TO BE PERSISTING AHEAD OF A WEAK SHORTWAVE TROF. THIS SHORTWAVE WAS HARD TO DECIPHER OFF THE SATELITTE PIX...BUT WAS DEPITECTED BY THE LATEST RUC. EXTRAPOLATED MOTION SHOULD KEEP THIS ACTIVITY WEST OF A RITZVILLE TO WILBUR LINE...HOWEVER THE RUC WANTS TO TAKE THE SHORTWAVE FARTHER EAST AND INTO THE SPOKANE AREA AROUND 09Z. CLOUD TOPS CONTINUE TO WARM OVER THAT REGION SO NOT CONFIDENT THE FEATURE HAS MUCH LONGER LIVE. POPS WERE CUT TO ZERO OVER THE REMAINDER OF THE CWA. ONLYT OTHER CHANGE FOR TONIGHT WAS TO INTRODUCE SOME PATCHY FOG OVER THE NE WA MOUNTAINS...SPOKANE AREA AND NORTH IDAHO PANHANDLE DUE TO THE RAINS OF EARLIER TODAY...CLEAR SKIES...LIGHT WINDS...AND LOW DEWPOINT SPREADS. REMAINDER OF FORECAST FOR TONIGHT LOOKS GOOD. FX && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 036 065 041 068 046 067/ 05 20 00 10 40 30 COEUR D'ALENE 037 064 039 067 043 067/ 05 20 00 05 40 30 PULLMAN 036 062 038 065 044 065/ 05 20 00 10 40 30 LEWISTON 040 068 044 071 046 070/ 00 20 00 20 40 30 COLVILLE 037 067 037 070 043 073/ 00 20 00 10 10 20 SANDPOINT 034 062 035 065 041 067/ 00 20 05 05 20 20 WALLACE 031 058 034 061 039 062/ 00 20 00 05 30 30 MOSES LAKE 038 073 044 074 047 073/ 20 00 00 10 40 30 WENATCHEE 044 074 049 075 052 072/ 10 00 00 20 40 20 OMAK 036 073 041 074 047 073/ 00 20 00 20 20 20 && .OTX... ID...NONE. WA...NONE. $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 344 AM CDT FRI MAY 14 2004 .DISCUSSION...FCST FOCUS ON PCPN CHCS TODAY AND TWDS END OF WEEKEND...AND TEMPS. DIFF CVA FM 500 MB SHRT WV OVR W CNTRL IL HELPING TO GENERATE PCPN OVR SERN WI/NE IL ALONG COLD FRONT WITH 05Z RUC ANALYZING A SECOND IMPULSE OVER ARKANSAS...AND A THIRD OVER SRN TX. ALL MODELS HAVING TROUBLE KEEPING THESE IMPULSES DISTINCT THRU ERLY FCST PD AND HAVE COMBINED THEM INTO A BROAD SHEARED VORT MAX LIFTING THRU RGN BETWEEN 12Z AND 18Z. SFC FNT/TROF HAS PUSHED THRU FAR SERN CWA WITH DRIER COOLER SFC AIR SPREADING INTO CWA. HOWEVER SHALLOW NATURE OF THIS SFC AIRMASS (STAYING AOB 925 MB THRU 12Z FRI) AHEAD OF 850 MB TROF REFLECTED IN FCST SNDGS...AND WITH SHRA/TSTMS LIFTING NE THRU WRN/CNTRL IA IN RGN OF BEST 850-700MB FRONTOGENTIC FORCING...WITH THE LIFT AUGMENTED BY ULD FROM RRQ OF UPR JET WHICH WILL LIFT SHRT WVS THRU RGN THIS AFTN. THIS MID LVL TROF AND ASSOC BAROCLINIC ZONE TO SHIFT EWD OVER CWA TODAY...AND INTO LWR MI BY 00Z SAT AS UPR JET SHIFTS EWD. OCCASIONAL SHRA WITH A RUMBLE OF THUNDER POSSIBLE THIS AM...AS ALL ABOVE ELEMENTS COMBINE OVER CWA...WITH PCPN TAPERING OFF THIS AFTN AS FORCING SHIFTS EWD AND COLUMN DRIES IN CAA REGIME AFTER 850 TROF PASSAGE...THO MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL HOLD CLOUDS IN UNTIL AFTER 02-04Z. SURFACE HI BUILDS IN OVERNIGHT AND SATURDAY...WITH DEEPER CAA CLEARING LINGERING CLOUDS LATE TONIGHT...BUT LOWER LAYERS STAYING WELL MIXED TO 850 MB UNTIL ALMOST 12Z...WITH LATE DECOUPLING OF WINDS. SOME SCT FROST FORMATION POSSIBLE AND WILL MENTION TO PROTECT THOSE WHO HAD EARLY PLANTINGS OF ANNUALS...ESPECIALLY IN LOW- LYING RURAL AREAS. HAVE OPTED FOR ADJUSTED TEMPS CLOSE TO MAV GUIDANCE AND PREV FCST. ONE MORE RELATIVELY COOL NIGHT SAT NGT...THEN WAA BEGINS ON SUN. INITIALLY BEST LIFT AND MOISTURE WILL FOCUS W AND NW OF CWA...THEN SHIFT OVER SUN AFTN/EVE. ZONAL FLOW NEXT WEEK KEEPS DISTURBED WX PATTERN IN PLACE WITH TEMPS AT OR SLIGHTLY BLO NORMALS. && .MKX...NONE. $$ REM wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LITTLE ROCK AR 930 AM CDT FRI MAY 14 2004 ...UPDATE OUT ALREADY... RADAR ECHOES ARE OPPOSITE THE POPS...SO UPDATED THE FORECAST TO KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FIRST PERIOD STATEWIDE. RUC SHOWS WEAK SHORT WAVE SUPPORTING THE CURRENT ACTIVITY. && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 32 ar AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1100 AM EDT FRI MAY 14 2004 .DISCUSSION... MAIN FCST CONCERNS THIS AFTERNOON ARE PCPN TRENDS AND TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED A MID LVL TROF FROM CNTRL CANADA THROUGH THE DAKOTAS TO THE SRN PLAINS AND A RDG OVER ERN NOAM LEAVING SW FLOW THROUGH THE WRN LAKES. ONE UPSTREAM SHRTWV WAS LOCATED OVER THE ERN DAKOTAS WHILE ANOTHER TO THE SOUTH WAS MOVING INTO NRN IL. AT THE SFC...A TROF EXTENDED FROM ERN ONTARIO AND NRN LK HURON TO ERN IL. AREA RADARS INDICATED A BROAD AREA OF -RA OVER THE ERN 2/3 OF WI AND MOST OF UPR MI SUPPORTED BY DEEP LYR QVECTOR CONV AND UPR LVL DIV WITH RIGHT ENTRANC OF H25 JET FROM WRN WI INTO NRN ONTARIO. IR LOOP INDICATED EXPANSION OF COLDER CLOUD TOPS OVER THE AREA. RADAR TRENDS AND 12Z RUC SUGGEST STEADY -RA WILL LINGER THROUGH 21Z OVER THE ERN 2/3 OF UPR MI WITH A DIMINISHING TREND OVER THE WEST DURING THE AFTERNOON. THE ETA IS SLIGHTLY FASTER WITH MOVING THE PCPN EAST. WITH CONTINUED SUPPORT FROM UPSTREAM SHRTWV...HAVE LEANED MORE TOWARD THE SLOWER RUC...EVEN THOUGH PCPN MAY TAPER OFF A BIT BTWN 18Z-21Z CNTRL. THE WEST SHOULD STILL SEE AT LEAST INTERMITTENT -RA THROUGH EARLY TO MID AFTERNOON. EXPECT PCPN TO QUICKLY TAPER OFF LATE THIS AFTERNOON AND EVENING FROM WEST TO EAST AS DYNAMICS AND DEEPER MOISTURE DEPART. PCPN AND THICK CLOUDS WILL KEEP TEMPS FROM CLIMBING MUCH THIS AFTERNOON WITH MAX READINGS ONLY A FEW DEGREES AT MOST ABV CURRENT READINGS FROM 37 TO 43 FROM NW TO SE. EVEN OVER THE WEST...WHERE PCPN MAY DIMINISH EARLIER...CAA WILL ALSO SUPPRESS ANY WARMUP. TEMPS LOWERED SLIGHTLY BUT GOING FCST WAS GENERALLY ON TRACK. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1008 AM EDT FRI MAY 14 2004 .SHORT TERM...TODAY'S 12Z SOUNDING A LITTLE DRIER THAN YESTERDAY'S. HOWEVER...IN LOOKING AT VARIOUS PARAMETERS...THE TOTAL-TOTALS AND SWEAT INDEX IS HIGHER AND WET-BULB ZERO HEIGHTS ARE QUITE A BIT LOWER. MODIFIED LI'S AND CAPE VALUES ALSO SUGGEST POTENTIAL FOR ISOLATED SEABREEZE CONVECTION. LATEST RUC SHOWING SOME ISOLATED SHWRS/TSTMS TO DEVELOP AROUND MIDDAY ON SEABREEZE. AS A RESULT...HAVE DECIDED TO ADD A SLGT CHC OF PRECIP INLAND FOR THE BALANCE OF THE DAYLIGHT HOURS. NO OTHER CHANGES TO CURRENT SHORT-TERM GRIDS. && .MARINE...SFC HIGH CENTERED PRETTY MUCH OVERHEAD THIS MORNING WITH LOCALIZED SEABREEZES DRIVING THE WIND FIELDS TODAY. SEAS REMAIN LIGHT WITH NO SIGNIFICANT CHANGES ANTICIPATED TO MARINE. && .AVIATION...CLEAR EARLY MORNING HOURS GIVING WAY TO SEABREEZE CUMULUS. THIS SHOULD BE THE CASE THROUGH THE AFTERNOON WITH AN ISOLATED SHOWER OR TSTM PSBL. && .PRELIMINARY POINT TEMPS/POPS... MHX 82 64 82 64 / 10 10 10 10 EWN 86 63 86 63 / 20 10 10 10 HSE 80 68 80 68 / 10 10 10 10 PGV 86 68 86 67 / 20 10 10 10 && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. && $$ 11/COLLINS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1000 AM EDT FRI MAY 14 2004 .PUBLIC...WX ELEMENTS IN THE ZFP LOOKS TO HAVE THE DAY/S CONDS HANDLED QUITE WELL. MORNING AND FCST SOUNDINGS MAINTAIN DECENT CAP WITH MODERATE CIN OVER THE AREA ALONG WITH NO DEFINITIVE FOCUS AREAS OF LIFT...INSTABILITY...NOR MOISTURE THOUGH PWATS HAVE INCRD TO AROUND THE 1.00 INCH AREA. RUC AND WSETA DO MAINTAIN ISOLD AREAS OF SEABREEZE CONVECTION BUT NOT ENOUGH WHERE IT WOULD WARRANT A CHANGE IN THE ZFP. IF IT OCCURS...COULD MOST LIKELY BE HANDLED WITH NOWCASTS. CLOUD STREAKS HAVE ALREADY BEGUN TO FORM ON VIS PIX MAINLY INLAND FROM ALL COASTAL COUNTIES SO PCLDY FOR ALL AREAS LOOKS GOOD. ONLY CHANGE WILL BE TO REWORD COASTAL SC COUNTIES WITH PCLDY INSTEAD OF MOSUNNY WITH ANTICIPATION OF MORE CU TO DEVELOP...BUT ALL OTHER ELEMENTS LOOK GOOD. && .MARINE...SE TO S FLOW OVER THE WATERS WILL CONTINUE THIS AFTERNOON. SEAS 2 TO 3 FT CLOSE TO SHORE AND AND 3 TO 5 FT IN THE GEORGIA WATERS OUTSIDE OF 20 NM. OVERALL...NO CHANGES TO THE FORECAST THIS AFTN. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. && $$ 24/8 sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1000 AM CDT FRI MAY 14 2004 .SHORT TERM...CLD TOP TEMPS ASSOCIATED WITH THE CONV LOCATED JUST SOUTH OF THE RIO GRANDE HAS BEEN STEADILY WARMING AND THE KBRO BASE REFLECTIVITY SHOWS THE CONV MOVING SLOWLY SE. THE 12Z BRO SOUNDING SHOWS A FAIRLY MOIST AND UNSTABLE AIRMASS IN PLACE WITH A PWAT OF AROUND 1.8 INCHES AND AN LI OF -6.3. HOWEVER...CONV FROM EARLIER THIS MORNING HAS LIKELY STABILIZED THE ATMS SOMEWHAT WHICH IS INHIBITING ANY ADDITIONAL SIGNIFICANT CONV FORMATION ATTM. IN ADDITION...PLENTY OF DEBRIS CLD COVER IS IN PLACE OVER THE BRO CWA WHICH WILL ALSO DELAY THE DAYTIME HEATING AND THE ASSOCIATED DESTABILIZATION. BOTH THE RUC AND MESO-ETA 5H FIELDS INDICATE THAT THE 5H SHORT WAVE AXIS IS ROUGHLY PARALLEL TO THE TX COASTLINE THIS MORNING. THIS POSITIONING WILL MAINTAIN CONV CHCS ALONG THE IMMEDIATE COASTLINE FOR TODAY AND WILL REALIGN THE POPS AND QPF ACCORDINGLY. WITH THE DEBRIS CLD COVER REDUCING THE AFTERNOON HEATING...THIS WILL LIKELY HOLD DOWN TEMPS TO NEAR OR BELOW GUIDANCE. NO OTHER CHANGES NEEDED IN THE CURRENT ZFP. && .MARINE...BUOY020 CURRENTLY REPORTS A NE WIND AT 17G23KT WITH 8 FT SWELLS. CLOSER TO SHORE...MTRPIL REPORTS A LIGHT NORTHERLY. WILL MAINTAIN THE SCA FOR THE OFFSHORE WATERS...BUT WILL LOWER IT ALONG THE LAGUNA MADRE. && .AVIATION...GENERALLY EXPECT VFR CONDITIONS TO CONTINUE IN THE CURRENT TAF PERIOD AS MID AND UPPER LEVEL CLD COVER DOMINATES. CURRENT TAF PACKAGE LOOKS OK. && .BRO WATCHES/WARNINGS/ADVISORIES...SCA FOR GMZ150-155-170-175. && $$ SYNOPTIC/GRIDS/AVIATION/MARINE...60 MESO...CAMPBELL/VEGA tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1014 AM EDT FRI MAY 14 2004 .UPDATE...NO CHANGE ANTICIPATED TO GOING FORECAST AT THIS TIME... ALTHOUGH ISOLATED POPS MAY NEED TO BE ADDED SOON FOR PART OF THE AREA. MORNING UA SOUNDINGS...AND RUC MODEL SOUNDINGS...SUGGEST AN AIRMASS SIMILAR TO YDA...WITH VERY LITTLE CAP...AND MUCAPE 1500 TO 2000. LIKE YDA...THINK MIXING THE BL WILL LOWER THESE CAPES SOMEWHAT. ALSO...HAVING A HARD TIME PICKING OUT ANY AREAS OF CONVERGENCE...OR FOCUS...FOR ANY CONVECTION. FOR THIS REASON...PLAN TO LEAVE ISOLD POPS OUT FOR NOW...BUT MY NEED TO ADD TO SOME ZONES...FOR EXAMPLE ALONG THE COAST...SHOULD ANY CONVERGENCE ZONES BEGIN TO SET UP. WILL MONITOR SATELLITE AND SURFACE OBS FOR INDICATIONS OF CONVERGENCE AREAS OR BOUNDARIES BEGINNING TO SET UP. ANY SHOWERS OR STORMS THAT DO DEVELOP SHOULD NOT APPROACH SEVERE LEVELS...AS WIND SHEAR EXTREMELY WEAK...AND CAPE ONLY MODEST. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. VA...NONE. NC...NONE. && $$ REILLY va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 1025 AM CDT FRI MAY 14 2004 .UPDATE... LATEST RADAR DATA INDICATED RAIN CONTINUING TO MOVE OUT OF THE FORECAST AREA AS WAVE ON SURFACE FRONT LIFTS NORTHEASTWARD INTO LOWER MICHIGAN. VISIBLE SATELLITE IMAGERY SHOWED CLEARING SKIES ADVANCING TOWARD SOUTHEAST MN AND NORTHEAST IOWA. HOWEVER...LOW LEVEL CLOUDS IN NORTHERLY FLOW BEHIND THE FRONT FILLING IN. OVERALL TREND OF DECREASING CLOUDS AS IN CURRENT FORECAST STILL APPEARS ON TRACK FOR THE AFTERNOON INTO EARLY EVENING...EXCEPT FOR CENTRAL WI...AS INDICATED BY LATEST RUC RELATIVE HUMIDITY PARAMETERS. PLAN TO SEND UPDATED ZONES AROUND 1045 AM WITH ANTICIPATION OF DRY FORECAST FOR THIS AFTERNOON. CHILLY TEMPERATURES FOR THIS TIME OF YEAR...WITH VALUES IN CURRENT FORECAST ON TRACK. && THOMPSON .SHORT TERM...TODAY THROUGH SUNDAY NIGHT FORECAST CONCERNS ARE ON PRECIPITATION TRENDS THIS MORNING...THE FOG AND TEMPERATURES TONIGHT WITH FROST POSSIBILITIES...THEN PRECIPITATION CHANCES LATER IN THE WEEKEND. 08Z SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY EXTENDING FROM NORTHERN LOWER MICHIGAN...THROUGH CHICAGO AND DOWN INTO SOUTH CENTRAL MISSOURI. AREA RADARS SHOWING SHOWERS FALLING TO THE NORTH OF THE FRONT IN VICINITY OF THE 850MB FRONT...ALTHOUGH BAND OF SHOWERS FALLING ACROSS NORTH CENTRAL IOWA AND SOUTHERN MINNESOTA ONLY PRODUCING A TRACE TO ONE HUNDRETH. 00Z 14MAY04 MODELS SHOWED NO MAJOR INITIALIZATION ERRORS AND WERE IN GOOD AGREEMENT THROUGH 48 HOURS. AFTER THAT...GFS STRONGER WITH 500 MB LOW COMING ONTO THE WEST COAST. UKMET SUPPORTS THE GFS SOLUTION SO WILL LEAN TOWARDS THIS IN THE LATER PERIODS. WEAK LIFT ACROSS THE AREA THIS MORNING WILL SLIDE EAST. MODELS PROG DRIER AIR TO ADVECT IN LATER TODAY...ALTHOUGH MAY HOLD ON TO A BROKEN CUMULUS DECK MUCH OF THE DAY...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. HIGH PRESSURE THEN BUILDS ACROSS THE GREAT LAKES TONIGHT AND PUSHES EAST OF THE AREA LATER SATURDAY. GOOD RADIATIONAL COOLING EXPECTED TONIGHT AND WITH ALL THE LOWER LEVEL MOISTURE WILL LIKELY SEE SOME AREAS OF FOG LATE. IN ADDITION...TEMPERATURES TO DROP OFF INTO THE LOWER TO MIDDLE 30S MOST LOCATIONS. WITH THAT IN MIND WILL ALSO MENTION SCATTERED FROST...BUT WILL HOLD OFF ON ANY HEADLINES. QUIET WEATHER TO CONTINUE THROUGH SATURDAY. ON SUNDAY...LOW PRESSURE TAKES SHAPE ON THE LEESIDE OF THE COLORADO ROCKIES. A WARM FRONT WILL EXTEND EAST FROM THE LOW ACROSS CENTRAL NEB AND INTO SOUTHERN MINNESOTA. BOTH GFS AND ETA HINTING CONTINUE TO SHOW CONVECTION NORTH OF THE FRONT ACROSS EASTERN SOUTH DAKOTA INTO SOUTHERN MINNESOTA. POP/WEATHER GRIDS HAVE A GOOD HANDLE ON THIS. ALTHOUGH WITH CONSISTENCY OF MODELS HAVE UPPED THE POPS FOR SUNDAY AFTERNOON. .LONG TERM...MONDAY THROUGH THURSDAY GFS CONSISTENT WITH LIFTING WARM FRONT ACROSS THE FORECAST AREA SUNDAY NIGHT FOLLOWED BY THE COLD FRONT ON MONDAY. LOOKS AS THOUGH A RATHER UNSETTLED PERIOD IS SETTING UP FOR LATE THIS WEEKEND INTO EARLY NEXT WEEK. CURRENT EXTENDED GRIDS HAVE THIS WELL IN HAND AND THUS WILL MAKE NO CHANGES. && .ARX...WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. WI...NONE. && $$ RABERDING wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU MAINE 341 PM EDT FRI MAY 14 2004 .SYNOPSIS...MOSTLY CLEAR SKIES THIS EVENING WILL ALLOW FOR FOG AND STRATUS TO DEVELOP ACROSS THE REGION TONIGHT AS TEMPERATURES COOL. A COLD FRONT WILL ENTER NORTHWEST MAINE SATURDAY AFTERNOON AND MOVE THROUGH THE STATE AND THEN OFF THE COAST BY SATURDAY EVENING. HIGH PRESSURE WILL RETURN FOR SUNDAY AND MONDAY. DISCUSSION... SHORT TERM (TONIGHT-SUNDAY NIGHT): WARM FRONT ABOUT TO CLEAR THE STATE THIS AFTERNOON WITH MOST AREAS RECEIVING PLENTY OF SUN EXCEPT FOR EXTREME NORTHERN MAINE AND THE SOUTHEAST CORNER OF THE STATE.SCATTERED SHOWERS A POSSIBILITY ALONG THE WESTERN BORDER WITH QUEBEC THIS AFTERNOON INTO EARLY THIS EVENING DUE TO SOLAR HEATING AND OROGRAPHIC LIFT. BUFKIT RUC SOUNDING INDICATING TT OF 50 AND K INDEX OF 35 WITH PW OF OVER AN INCH. DEVELOPMENT ALREADY TAKING PLACE WITH SCATTERED SHOWERS FROM NORTHERN MAINE TO CHAMBERLAIN LAKE. EXPECT ACTIVITY TO DIE DOWN AFTER SUNSET WITH THE LOSS OF SOLAR HEATING. LOW CLOUDS AND FOG TO DEVELOP OVER OUR CWA BEFORE MIDNIGHT AS SOUTHERLY LOW LEVEL MOIST FLOW COOLS. AREAS OF FOG AND STRATUS WILL LIFT DURING THE MORNING GIVING MOST AREAS SOME SUN BY LATE MORNING. COLD FRONT WILL ENTER NORTHWEST MAINE MID AFTERNOON AND THEN OFF THE COAST BEFORE MIDNIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG A PRE FRONTAL TROUGH CROSSING THE NORTH EARLY IN THE AFTERNOON...ACROSS CENTRAL MAINE BY MID AFTERNOON AND THEN ACROSS SOUTHERN SECTIONS DURING THE LATE AFTERNOON. CAPE VALUES VERY LOW ACROSS THE NORTH BUT JUST OVER 1000 JOULES ACROSS THE SOUTHERN SECTIONS. HIGH PRESSURE WILL RIDGE ACROSS THE REGION SATURDAY NIGHT AND THEN MOVE NORTH OF THE STATE ON SUNDAY. WITH ZONAL FLOW ALOFT...FRONT WILL STALL OVER THE GULF OF MAINE AND CLOUDS MAY LINGER ACROSS SOUTHERN SECTIONS UNTIL MIDDAY SUNDAY. SHORTWAVE RIDGE WILL BUILD ACROSS THE STATE SUNDAY NIGHT INTO MONDAY WITH MOSTLY CLEAR SKIES. LONG TERM (MONDAY INTO FRIDAY): LEANED W/A CONSENSUS OF ETA/GFS & GEM FOR MONDAY INTO TUESDAY AS HIGH PRES BUILDS E INTO THE CANADIAN MARITIMES, EH. SOME CONCERN IS THERE FOR SOME DAMMING/WEDGING TO SET UP W/HIGH FCST TO BE ENE OF THE REGION. HINTED AT THIS IN GRIDS FOR MON W/MORE CLOUDS ACROSS NNE PORTION OF THE CWFA. FURTHER S...SHOULD BE ABLE TO GET AWAY W/PC CONDITIONS. TEMPS WILL BE TRICKY IF THIS SCENARIO PANS OUT. DID MAKE SOME ADJUSTMENTS TO MONDAY'S MAXES. NEXT FRONTAL BOUNDARY APPROACHES LATE TUESDAY INTO WEDNESDAY W/A ROUND OF SHOWERS. ATTM...DECIDED TO LEAVE ANY MENTION OF TSRA OUT GIVEN IT IS DAYS 4 & 5. STILL PLENTY OF TIME TO ASSESS THINGS. PLUS...IF DAMMMING/WEDGE DOES TAKE PLACE...THEN CONVECTION WILL BE LIMITED STABLE LLVLS. NOT BUYING INTO THE WAD OF QPF THAT THE GFS IS SHOWING GIVEN LACK OF SIGNIFICANT MOISUTRE TRANSPORT. FRONT IS FORECAST TO CLEAR THE COAST WED AFTERNOON WITH HIGH PRES BUILDING INTO THE REGION ON THURSDAY PROVIDING FOR DECENT WX. TEMPS ARE A REFLECTION OF THE MRF/MEX W/USUAL ADJUSTMENTS. MARINE: HAVE STAYED CLOSE TO ETA12 WINDS THROUGH 12Z MONDAY. FOR THE REMAINDER OF THE FORECAST HAVE MODIFIED GFS WINDS DOWN TO BETTER FIT LOWER STABLE LAYER. TEMPERATURE DEW POINT SPREAD AT 44027 STILL AROUND 6 DEGREES AND IS NOT CHANGING VERY MUCH. SUSPECT WE WILL HAVE TO WAIT UNTIL LATER THIS AFTERNOON FOR STRONGER SOUTHERLY FLOW BEFORE FOG DEVELOPS. LOOKING FOR FOG ACROSS THE WATERS TONIGHT THROUGH SATURDAY...THEN VISIBILITY IMPROVING EARLY SATURDAY NIGHT AS WINDS SHIFT INTO THE SOUTHWEST BRINGING IN DRIER AIR. HAVE INITIALIZED GRIDS WITH WNA WAVE WATCH III. HAVE LOWERED WAVE HEIGHTS 1 TO 2 FT BELOW WAVE MODEL NUMBERS TO BETTER FIT WINDS IN STABLE LAYER ACROSS OUR WATERS THROUGH SATURDAY. EXPECT MOST OF WAVES SATURDAY FROM SOUTH OF THE GULF OF MAINE WHERE WINDS ARE MIXING DOWN BETTER. AVIATION: VFR CONDITIONS WILL DETERIORATE TO MVFR CONDITIONS AT ALL TAF SITES THIS EVENING. CLEARING SKIES...WET GROUND & SLY FLOW WILL LEAD TO THE POTENTIAL FOR IFR CONDITIONS BOTH FOR CIGS/VSBYS AFT 07Z. .CAR...NONE. NEAR TERM/AVIATION: WOLFE SHORT TERM/MARINE: FOSTER LONG TERM/MARINE: HEWITT me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 410 PM EDT FRI MAY 14 2004 .DISCUSSION... WATER VAPOR IMAGERY/RUC ANALYSIS SHOW MIDLEVEL TROF FROM CENTRAL CANADA S INTO THE PLAINS STATES. SEVERAL SHORTWAVES WERE LIFTING OUT OF THE TROF WITH THE ONE OVER MN BEING THE MOST IMPORTANT FOR THIS AREA. AS HAD BEEN EXPECTED...A SOLID SHIELD OF RAIN SPREAD ACROSS MOST OF UPPER MI TODAY WITH TEMPS UNSEASONABLY COOL IN THE UPPER 30S TO MID 40S. HIGH TEMP OF 40 JUST AFTER MIDNIGHT HERE AT THE OFFICE TIES RECORD LOW MAX TEMP FOR THE DAY (ETA HAD A GREAT HANDLE ON TEMPS TODAY AS FAR BACK AS MODEL RUN 12Z WED). BACK EDGE OF RAIN HAS PROGRESSED TO THE ERN U.P. WITH SOME SPRINKLES/DZ LINGERING FROM THE KEWEENAW TO NCNTRL AREAS IN MOIST UPSLOPE FLOW. NO SIGNIFICANT MODEL DIFFERENCES NOTED TODAY THAT WILL REALLY AFFECT SENSIBLE WX IN THE SHORT TERM. BASED ON LINEAR EXTRAPOLATION...-RA SHOULD BE OUT OF ERN COUNTIES BY START OF TONIGHT PERIOD (22Z)...BUT WILL CARRY SOME SPRINKLES/-DZ EARLY THIS EVENING KEWEENAW/NCNTRL EWD DUE TO MOIST UPSLOPE FLOW EARLY. SFC HIGH THEN SETTLES OVER WI/WRN UPPER MI BY 12Z SAT. QUITE A BIT OF STRATOCU LINGERS OVER NRN MN JUST AHEAD OF SFC RIDGE AXIS...BUT IT IS BECOMING MORE CELLULAR AND IS MIXING OUT A BIT. HOWEVER...SINCE DAYTIME HEATING WILL NOT BE ABLE TO MIX MOST OF IT OUT BEFORE SUNSET...BELIEVE IT MAY TAKE A WHILE FOR CLOUDS TO CLEAR OUT OF FCST AREA TONIGHT. WILL TREND SKY TO MOSTLY CLEAR OVER WRN AREAS AROUND MIDNIGHT...AND BRING A DECREASING CLOUD TREND TO ERN AREAS LATE. ETA/GFS MOS TEMPS LOOK PRETTY GOOD OVER THE W WHERE SKIES CLEAR (TEMPS BLO FREEZING INTERIOR). FROST/FREEZE HEADLINES ARE NOT BEING ISSUED YET (BEGINS MAY 22ND). COOL/PLEASANT DAY ON TAP SAT AS HIGH PRES DRIFTS E ACROSS UPPER MI. SHOULD BE A DECENT DISPLAY OF SUNSHINE...THOUGH WITH 850MB THERMAL TROF OVER THE AREA...WILL LIKELY SEE SCT TO MAYBE BKN CU DEVELOP FOR A TIME LATE MORNING/EARLY AFTN...ESPECIALLY INTERIOR E HALF. GOING FCST OF GENERALLY MID 50S AWAY FROM LAKE SUPERIOR LOOKS FINE AND AGREES WELL WITH UPSTREAM TEMPS TODAY AND WITH LATEST ROUND OF MOS GUIDANCE. HIGH SLIPS E AND RETURN FLOW/WAA DEVELOPS ACROSS THE ENTIRE AREA SAT NIGHT AS SHORTWAVE TRACKS ACROSS ND TO WRN ONTARIO. ASSOCIATED SFC FRONT REACHES FAR NE MN 12Z SUN. ISENTROPIC ASCENT IS FAIRLY STRONG DURING THE NIGHT (295K SFC)...BUT INITIAL MOISTURE RETURN IS LIMITED AND NO ELEVATED INSTABILITY IS PRESENT IN FCST SOUNDINGS...SO HAVE NOT INCLUDED ANY PCPN MENTION ATTM. LATER SHIFTS WILL NEED TO WATCH THIS TIME FRAME FOR POTENTIAL PCPN INCLUSION. FOR NOW...JUST EXPECT AN INCREASE IN CLOUD COVER IN WAA REGIME. FRONTAL BNDRY WILL ONLY DRIFT INTO WRN UPPER MI SUN AS ADDITIONAL SHORTWAVE ENERGY HEADS THRU THE DAKOTAS TOWARD UPPER MISSISSIPPI VALLEY. ETA SHOWS MLCAPE INCREASING TO A FEW HUNDRED J/KG OVER THE W WITH LITTLE/NO CIN...BUT ITS BNDRY LAYER MOISTURE PROFILE LOOKS A BIT TOO MOIST. NONETHELESS...WITH FRONTAL BNDRY IN THE AREA AND ETA/GFS HINTING AT SOME PCPN...WILL LEAVE GOING FCST OF CHC POPS OVER ABOUT THE W HALF OF FCST AREA FOR SUN AFTN. SUN NIGHT/MON...PCPN CHANCES INCREASE SUBSTANTIALLY AS WEAK SFC WAVE IS INDUCED ALONG FRONTAL BNDRY BY APPROACHING SHORTWAVE. SIGNIFICANT UPPER LEVEL DIVERGENCE DEVELOPS OVER WRN GREAT LAKES UNDER RIGHT ENTRANCE OF JET DEVELOPING OVER ONTARIO. LOW-LEVEL JET RESPONDS... INCREASING TO 50KTS INTO SRN WI WITH 850MB DWPTS RISING TO 6-8C INTO UPPER MI. CONVERGENCE ALONG 850MB WARM FRONT LIFTING INTO SRN UPPER MI WILL FURTHER AID PCPN DEVELOPMENT. HAVE THUS RAISED POPS TO LIKELY FROM SW TO NE ACROSS FCST AREA SUN NIGHT INTO MON MORNING WITH DIMINISHING TREND FROM W TO E MON AFTN. TUE THRU FRI...GFS/CANADIAN/UKMET/ECMWF ARE IN VERY GOOD AGREEMENT FOR THIS TIME FRAME. AT THE BEGINNING OF THE PERIOD...ALL THE MODELS SHOW HIGH PRES BUILDING OVER THE GREAT LAKES TUE IN THE WAKE OF MONDAYS RAIN EVENT. WITH GOOD AGREEMENT TIMING-WISE...NEXT SYSTEM OF CONCERN ARRIVES LATER WED/THU. MAIN DIFFERENCE NOTED IS THAT 00Z/06Z GFS ARE STRONGER WITH THE NRN STREAM DIGGING INTO UPPER LAKES/NEW ENGLAND. PER GFS ENSEMBLE MEAN/HPC GUIDANCE...WILL NOT GO WITH AS MUCH COOLING BEHIND SYSTEM THU/FRI. LOOKS LIKE A FAIRLY DRY WRLY FLOW WILL BE PREVALENT PRIOR TO SYSTEM ARRIVING WED NIGHT/THU...SO WILL CONTINUE TO HOLD OFF ON SHRA CHC UNTIL WED NIGHT. FAIRLY PROGRESSIVE FLOW SHOULD KEEP WINDOW OF SHRA OPPORTUNITY SHORT WITH FRONT LIKELY THRU THE AREA EARLY THU...THEN DRY THU NIGHT/FRI. TEMPS SHOULD BE CLOSE TO NORMALS THRU THE PERIOD WITH WED THE WARMEST DAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi