AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 955 AM PDT WED MAY 12 2004 .DISCUSSION... NORCAL REMAINS BETWEEN SYSTEMS THIS MORNING WITH UPPER TROUGH SLOWLY EXITING THE GREAT BASIN AND RIDGE BUILDING OVER THE EAST PACIFIC. TOUGH TO PICK OUT ANY SHORT WAVES EMBEDDED IN NORTHWEST FLOW ALOFT OVER OUR AREA...BUT BOTH THE GFS AND THE RUC SHOW A WEAK SHORT WAVE PASSAGE FOR THIS AFTERNOON. RESULTANT INSTABILITY APPEARS QUITE WEAK AND FOCUSED JUST SOUTH AND EAST OF OUR AREA...SO DRY FORECAST LOOKS GOOD FOR NOW. MORNING AIR RESOURCES BOARD LOW LEVEL SOUNDINGS SUPPORT SEVERAL DEGREES OF WARMING TODAY...SO GOING FORECAST IS IN GOOD SHAPE. NO UPDATES PLANNED. JJ && .STO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 950 AM EDT WED MAY 12 2004 .DISCUSSION... 10Z CAPE SOUNDING SHOWS PLENTIFUL LOW LVL MOISTURE BELOW 850 MB WITH A DRY LAYER FROM 850-650 MB. LOW LVL CONVERGENCE CLOUD LINES IN SE FLOW ALLOWING A FEW SHOWERS TO TO MOVE NW TWD THE COAST AND A FEW INTO THE INTERIOR. IN THE MID AND UPPER LVLS...WATER VAPOR IMAGERY AND RUC UPPER STREAMLINES/ VORTICITY FORECASTS UPR LVL TROUGH ACROSS THE ERN GULF WITH MID AND HIGH LEVEL MOISTURE ACROSS THE PENINSULA. ENOUGH MID LEVEL LIFT TO ALLOW FOR SOME LIGHT PRECIP RETURNS MOVING NE ON KMLB/KTBW 88D COMPOSITE REFLECTIVITY...THOUGH THIS PRECIP PROBABLY JUST FALLING FROM 12KFT-14KFT AS VIRGA. UPPER TROUGH AXIS POISED TO SLIDE SE AS HEIGHTS BEGIN TO BUILD ACROSS THE CENTRAL AND ERN GULF BY THIS EVENING. WILL MONITOR RADAR TRENDS AND MAY NEED TO ADD A LESS THAN 20 PCT POP FOR A FEW SHOWERS IN ESE FLOW. HIGH TEMP FORECASTS GENERALLY IN LINE BUT MAY TRIM A DEG OR TWO FROM SOME INTERIOR SPOTS. OTHERWISE LITTLE CHANGE TO MORNING FORECAST. && .MARINE...WINDS/SEAS CURRENTLY RUNNING 13-18KT/4-5FT WHICH IS RIGHT IN LINE WITH THE CWF. ISOLD MARINE SHRA WITH CELL OFFSHORE KXMR ACTUALLY SPITTING OUT SOME LTG IN SPITE OF THE FORMIDABLE WARM/DRY MID LEVELS. DON'T PLAN ON PUTTING TS INTO THE CWF AS MORE INTENSE ACTIVITY SHOULD WEAKEN BY AFTN. CWF WILL REMAIN ESSENTIALLY UNCHANGED. && .MLB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...VOLKMER LONG TERM...CRISTALDI fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 342 PM CDT WED MAY 12 2004 .DISCUSSION... MAIN FORECAST CHALLENGES WILL BE RAIN CHANCES AND THE AMOUNT OF RAIN THROUGH THURSDAY NIGHT. LATEST SURFACE MAP AND RADAR HAD FRONTAL BOUNDARY FROM NEAR SENECA TO MANHATTAN TO ABILENE. FRONT HAS BEEN MOVING VERY SLOWLY AND MAY BE STARTING TO SLOW UP. SATELLITE SHOWING NEXT WAVE MOVING ACROSS COLORADO THIS AFTERNOON. FRONT FORECAST TO STALL ACROSS THE CWA THIS EVENING AS UPPER ENERGY EJECTS OUT TONIGHT INTO THE PLAINS WHICH CAUSES THE 850 MB WINDS TO BACK THIS EVENING. INCREASING LOW LEVEL JET TONIGHT OVER THE FRONT WILL PUMP UP HIGH PRECIPITAL WATER VALUES...IN EXCESS OF 150 PERCENT OF NORMAL. STRONG CONVERGENCE ALONG THE FRONT THIS AFTERNOON SHOULD BE ENOUGH TO DEVELOP SURFACE BASED CONVECTION ALONG THE FRONT AS CAP WEAKENS. LATEST RUC HAD CONVECTION FIRING ALONG THE FRONT FROM NORTHWEST OKLAHOMA INTO SOUTH CENTRAL KANSAS THIS EVENING NORTH INTO NORTHEAST KANSAS. HAVE ISSUED A FLOOD WATCH FOR TONIGHT THROUGH NOON THURSDAY FOR POINTS NORTH OF INTERSTATE 70. THIS AREA HAS RECEIVED ONE TO THREE INCHES OF RAIN OVER THE PAST FEW DAYS. CELLS MAY FOCUS IN NORTH CENTRAL KANSAS THEN MOVE NORTHEAST PARALLEL TO THE FRONT ACROSS NORTHEAST KANSAS. MCS GOOD BET TO DEVELOP LATER TONIGHT AND PROPAGATE ACROSS THE CWA THROUGH THURSDAY MORNING. WILL CONTINUE WITH HIGH POPS ON THURSDAY MORNING THEN DECREASE LATER IN THE AFTERNOON. FRONT IS FORECAST TO PUSH THROUGH THE CWA DURING THE AFTERNOON HOURS. TIGHT THERMAL GRADIENT BEHIND THE FRONT ON THURSDAY WILL MAKE HIGHS A CHALLENGE. CHANCES OF PRECIPITATION WILL CONTINUE THROUGH THURSDAY NIGHT WHEN UPPER TROUGH MOVES THROUGH. IN THE EXTENDED...GFS NOW HINTING AT A POSSIBLE MCS DEVELOPING SUNDAY NIGHT IN NORTH CENTRAL KANSAS THEN PROPAGATING EAST THROUGH THE MORNING ON MONDAY. KANSAS WILL BE ON THE SOUTH END OF THE WESTERLIES WITH SHORTWAVES MOVING THROUGH. A FRONT SETTLES DOWN INTO NORTHERN KANSAS BY TUESDAY...PROVIDING A FOCUS FOR NOCTURNAL CONVECTION. GRADUALLY WARMED TEMPERATURES THROUGH THE EXTENDED. && .TOP...WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH FROM MIDNIGHT TONIGHT THROUGH NOON CDT THURSDAY...MAINLY NORTH OF AN ABILENE TO JUNCTION CITY TO HOLTON LINE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1015 AM MDT WED MAY 12 2004 .UPDATE...RELEASED A ZONE UPDATE TO BUMP WINDS UP INTO THE BREEZY TO WINDY CATEGORY THIS AFTERNOON SOUTH OF THE INTERSTATE. LOW PRESSURE WILL DEEPEN OVER SOUTHEAST COLORADO/WESTERN KANSAS THIS AFTERNOON. RUC INDICATES POSSIBILITY OF 30 KNOT SUSTAINED WINDS AROUND 00Z. GIVEN THE LATE TIMING OF THE INCREASE...EXPECT NOCTURNAL INVERSION TO KEEP THINGS BELOW WIND ADVISORY CRITERIA FOR ALL BUT A SHORT TIME THIS EVENING. WILL PROBABLY HANDLE THE EVENING WINDS WITH NOWCASTS RATHER THAN AN ADVISORY. MAIN CONCERN...HOWEVER...IS SEVERE WEATHER IN THE SOUTHERN COUNTIES. THE ENVIRONMENT WILL BE CHARACTERIZED BY VERY STRONG SHEAR AND VEERING WIND PROFILES FAVORABLE FOR SUPERCELL THUNDERSTORMS WITH LARGE HAIL. SEE THE SPC DAY 1 OUTLOOK FOR DETAILS. MAIN QUESTION WILL BE INSTABILITY...WHICH LOOKS TO BE MARGINAL...BUT INCREASING THROUGHOUT THE EVENING FROM GOVE TO TRIBUNE TO CHEYENNE WELLS. MADE NO CHANGES TO AFTERNOON TEMPERATURES...AS NEW GUIDANCE SUPPORTS THE PREVIOUS FORECAST. BURKE. .PREV DISCUSSION... 227 AM MDT WED MAY 12 2004 FORECAST CONCERNS ARE ON RECENT FRONTAL PASSAGES IMPACT ON TEMPERATURES TODAY AND THREAT FOR SEVERE WEATHER OVER WESTERN AND SOUTHERN PORTIONS OF THE AREA. TODAY/TONIGHT...FOCUS WILL BE ON THE POSITION OF THE COOL FRONT AND ITS AFFECTS ON SEVERE WEATHER POTENTIAL. CURRENT THINKING IS FOR SURFACE WINDS TO GRADUALLY VEER AROUND TO THE EAST OR NORTHEAST OVER MUCH OF THE AREA AS HIGH PRESSURE DESCENDS FROM CANADA. OVER MUCH OF EASTERN COLORADO SOUTHEAST THROUGH THOSE COUNTIES SOUTH OF THE INTERSTATE MOISTURE/INSTABILITY AND LIFT ALL COMBINE WITH AN EJECTING VORT MAX AND RIGHT REAR QUAD OF DEPARTING 250 JET TO CREATE A MODEST THREAT FOR SEVERE WEATHER. ALL THE INGREDIENTS ARE IN PLACE ITS NOW A MATTER OF LOOKING FOR SOMETHING TO SCREW IT UP. SPC HAS REALLY JUMPED ON BOARD IN THE DAY 1 OUTLOOK COMPARED TO YESTERDAYS DAY 2 OUTLOOK FOR THE SAME TIME PERIOD. WILL HAVE HIGHEST POPS ALONG THE BOUNDARY LATE IN THE DAY. POST FRONTAL LOW CLOUDINESS QUICKLY FILLS IN AS SURFACE WINDS BECOME NORTHERLY. DESPITE DECREASING LIFT AFTER 06Z AS UPPER DYNAMICS MOVE NORTHEAST OF US MODELS CONTINUE TO PAINT SOME PRETTY HIGH POPS. WILL KEEP THE CHANCE OF SHOWERS IN THE FORECAST AS VARIOUS WAVES AT 500 MB MOVE ACROSS FROM THE SOUTHWEST. THURSDAY/THURSDAY NIGHT...NORTH TO NORTHEAST WINDS AND BELOW NORMAL TEMPERATURES WILL BE OBSERVED AS HIGH PRESSURE SETTLES INTO THE AREA. MODELS HAVE BEEN CONSISTENT WITH AFTERNOON TEMPERATURES IN THE 50S SO CONFIDENCE IS MODEST. STILL HAVE SOME DYNAMICS WITH UPPER TROUGH AXIS OVERHEAD SO WILL KEEP A SLIGHT CHANCE OF SHOWERS IN THE FORECAST. FOR THURSDAY NIGHT SURFACE HIGH MOVES RIGHT OVER TOP OF US LEADING TO CLEARING SKIES AND RELATIVELY LIGHT WINDS. MOS AND 2M TEMPERATURES ARE IN THE BALLPARK WITH EACHOTHER SO WILL NOT STRAY FAR. FRIDAY/FRIDAY NIGHT...FLOW BECOMES A BIT MORE ZONAL ALOFT WITH SURFACE HIGH QUICKLY MOVING EAST. GFS/ETA 850 TEMPERATURES AS WELL AS MOS/2M TEMPERATURES ADVERTISING HIGHS BACK INTO THE MID 60S. SOUTHERLY WINDS RETURN FRIDAY NIGHT WITH MODERATING MIN TEMPERATURES. SATURDAY THROUGH WEDNESDAY...NO CHANGES MADE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 230 PM EDT WED MAY 12 2004 CUMULUS DEVELOPED RAPIDLY EARLIER THIS AFTERNOON AS CONVECTIVE TEMPERATURES WERE REACHED. NO DISTURBANCES OR BOUNDARYS TO FOCUS CONVECTION ARE APPARENT...BUT EXPECT SCATTERED THUNDERSTORMS LATER THIS AFTERNOON JUST LIKE YESTERDAY. THE AXIS OF GREATEST INSTABILITY FORECASTED BY THE RUC THIS AFTERNOON HINTS THAT THE BEST CONCENTRATION OF CONVECTION WILL DEVELOP ALONG AND EAST OF INTERSTATE 65 AND ACROSS THE BLUEGRASS REGION. LESS CU DEVELOPMENT IN WESTERN KENTUCKY IS ASSOCIATED WITH WEAK SUBSIDENCE AHEAD OF A DISTURBANCE ALONG LOWER MISSISSIPPI VALLEY. CLOUDS WILL INCREASE TONIGHT AS CONVECTIVE DEBRIS CURRENTLY WIDESPREAD ALONG THE MISSISSIPPI RIVER WILL MOVE INTO CENTRAL KENTUCKY AFTER MIDNIGHT. A WEAK UPPER LEVEL TROUGH ASSOCIATED WITH CURRENT CONVECTION ACROSS ARKANSAS WILL MOVE NORTH ACROSS WESTERN PART OF STATE EARLY THURSDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND BEGIN TO MOVE INTO WEST CENTRAL CWA WELL AFTER MIDNIGHT IN RESPONSE TO SUBTLE MID-LEVEL HEIGHT FALLS. WITH INCREASED CLOUD COVER AND SCATTERED CONVECTION...THURSDAY'S HIGHS WILL NOT BE AS WARM AS THIS AFTERNOON'S. WARM HUMID MODIFIED SUBTROPICAL AIR WILL REMAIN OVER THE ENTIRE REGION THROUGH LATE FRIDAY. BEST CHANCE OF WIDESPREAD PRECIPITATION WILL DEVELOP FRIDAY EVENING AND OVERNIGHT. A COLD FRONT ASSOCIATED WITH LOW PRESSURE ACROSS THE WESTERN GREAT LAKES WILL CROSS CWA OVERNIGHT FRIDAY. DRIER AND SLIGHTLY COOLER AIR WILL ARRIVE BEHIND FRONT DURING THE DAY SATURDAY. .IN THE EXTENDED (SATURDAY NIGHT THROUGH WEDNESDAY)... RIDGING WILL STILL EXTEND OVR THE EAST COAST SAT NITE WITH AN APPROACHING TROUGH...THE COLD FRONT WILL MOST LIKELY BE SOUTH AND EAST OF THE FORECAST AREA...BUT STALL OUT JUST SOUTH OF THE FORECAST AREA SUNDAY. A FEW DRY DAYS WILL FINALLY OCCUR SUN INTO MON AS THE UPPER FLOW FLATTENS OUT AND THE RIDGE REMAINS ACROSS THE SE STATES. THE FRONT WILL MOVE BACK NORTH MON AS A WARM FRONT...MOISTURE FROM THE GULF WILL OPEN UP WITH SLIGHTLY HIGHER THAN NORM TEMPS RETURNING. BOUNDARY WILL REMAIN NEAR THE FORECAST AREA TUES AND WED...WITH INSTABILITY AND THEREFORE THE POSSIBILITY OF TSTORMS BOTH DAYS. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. && $$ JSD/BS ky AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1045 AM EST TUE MAY 11 2004 UPDATING THE FORECAST TO MAINLY REMOVE ANY MENTION OF MORNING/AFTERNOON WORDING. CURRENT FORECAST LOOKS TO BE RIGHT ON TRACK AND ONLY MADE MINOR SKY COVER CHANGES IN THE GRIDS. ISOLATED SHOWERS AND THUNDERSTORMS SHOULD BEGIN DEVELOPING DURING MAX DAYTIME HEATING. LATEST RUC AND MESOETA MODELS INDICATE A WEAK SHORTWAVE MOVING NORTH ALONG THE EASTERN CWFA IN THE AFTERNOON. THIS COULD HELP ENHANCE ANY BAY BREEZE ACTIVITY THAT DEVELOPS. OTHERWISE...ANY STORMS THAT FIRE WILL BE DRIVEN BY LEFT OVER MESOSCALE BOUNDARIES FROM YESTERDAY. LISTEMAA PREVIOUS DISCUSSION................................................. .SHORT TERM... SUMMER PTTN NXT 24 HRS...AS HIPRES RDG SFC-ALOFT REMAINS PARKED OFF CAROLINA COAST...PUMPING WARM..HUMID AIR ACRS CWFA. H8 TEMPS REMAIN NEAR 14-15C...SO SEE LTLCG TO MAXT FCST. DONT SEE MUCH FOR FORCING EITHER...WHICH MEANS THAT MESOSCALE BNDRYS WL INTERACT W/ OROGRAPHICS FOR WIDELY SCT LATE DAY-ELY EVNG CNVCTN. ATMOS CERTAINLY UNSTBL ENUF TO SUPPORT IT. MAY ALSO BE A TSRA SOMEWHERE NEAR THE BAY-RIVER BRZ BNDRY...BUT CVRG WL BE ISOLTD. WL TRIM POPS BACK TO THE MID TEENS-MID 20S...WHICH WL ROUND FOR A BLANKET 20 AREAWIDE AFTN-EVE. GRIDS WL DEPICT BTTR CHC IN THE MTNS. && .AVIATION...MVFR VSBY TIL SUNUP DUE TO HIGH RH. MAY BE SOME LCL IFR IN VLYS...SPCLY INVOF CHO DUE TO YDA PCPN. ANTICIPATE IMPVG VSBY AFTR 12-13Z. WIDELY SCT TSRA IN THE AFTN-EVE AREAWIDE. XPCT INITIATION TO OCCUR NEAR MTN RDGS...HAVING GREATEST IMPACT ON CHO AND MRB. && .MARINE...SLY FLOW LIKELY TO BECOME CHANNELED UPSTREAM...AND THEN TURN ONSHORE IN THE AFTN. && .HYDROLOGY...PWAT 1.25-1.50 INCHES. LC STORMS CUD BE HVY RAINERS. HWVR...DONT ANTICIPATE MUCH IN WAY OF PROBLEMS. && .LONG TERM... THURSDAY THROUGH NEXT WEEK... H5 RIDGE CONTINUES TO BLOCK IMPULSES FROM TRIGGERING MORE THAN ISOLATED CONVECTION OVER AREA THROUGH FRIDAY. ON SATURDAY HIGH MOVES EASTWARD AHEAD OF APPROACHING FRONT TRIGGERING MORE THUNDERSTORMS INCREASING CLOUDINESS OVER THE AREA. ETA SOLUTION IS FAVORED WITH DRIER REGIME AS FRONT APPROACHES. FRONT STALLS OVER AREA SUNDAY AND MONDAY INCREASING POPS THEN DRIFTS NORTH ON TUESDAY. DECIDED TO INCREASE POPS SLIGHTLY BUT OTHER THAN THAT NO MAJOR CHANGES MADE TO THIS MORNINGS PACKAGE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ HTS/DICARLO md AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TAUNTON MA 1145 AM EDT WED MAY 12 2004 .SHORT TERM... THIS AFTERNOON AND TONIGHT FORECASTS WERE UPDATED TO ACCOUNT FOR CURRENT CONDITIONS AND TO ADJUST MAX TEMPERATURES. WE ARE ALSO WATCHING CONVECTION DEVELOP ACROSS UPSTATE NY AND EASTERN PA WHERE THE AIRMASS IS MORE UNSTABLE... AND ALSO HAS SOME HELP FROM A WEAK SHORT WAVE AT 500 MB. RUC AND BOX ETA-10 SHOW THIS ACTIVITY SLOWLY SPREADING E INTO THE HUDSON VALLEY THIS AFTERNOON AS THE SHORT WAVE HEADS TOWARD CT. BOTH MODELS ALSO SUGGEST SOME CONVECTION COULD REACH OUR CT VALLEY ZONES TOWARD EVENING...AS THEY END UP ON THE EASTERN EDGE OF THE INSTABILITY AXIS AND GET SOME ADDED SUPPORT FROM THE SHORT WAVE. IT LOOKS LIKE MOST OF THE CONVECTION WILL BE FOCUSED ON WEAK BOUNDARIES OR TERRAIN FEATURES. LOCALLY HEAVY RAINFALL WOULD BE THE MAIN THREAT GIVEN HIGH PRECIPITABLE WATER VALUES AND WEAK WIND FIELDS ALOFT. .LONG TERM... THU THROUGH NEXT WED FORECAST THROUGH THE WEEKEND STILL LOOKS VALID. WE ARE IN THE WARM SECTOR SAT BEFORE THE COLD FRONT APPROACHES LATE IN THE DAY...SO WE ARE PLANNING TO LEAVE CHANCE POPS FOR SHOWERS AND THUNDERSTORMS LATE SAT INTO SAT NIGHT. FRONT PUSHES S OF NEW ENGLAND SUN ALLOWING FOR DRY AND COOLER WEATHER SUN AND MON. WE ARE LEANING TOWARD GFS ENSEMBLES AND HPC GUIDANCE FOR TUE AND WED. ANOTHER COLD FRONT WILL BE MOVING E FROM THE GREAT LAKES TUE... AGAIN PUTTING US IN THE WARM SECTOR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON. WE ARE GOING ABOVE MEX GUIDANCE AND SIDING CLOSER TO THE HIGH END OF THE ENSEMBLE MOS. DRY AND COOLER WEATHER IS EXPECTED WED AS THE FRONT PUSHES OFFSHORE. DESPITE 00Z GFS SHOWING MEASURABLE RAINFALL...ENSEMBLE MEAN SHOWS FRONT S OF NEW ENGLAND WITH A LOW PROBABILITY (BELOW CLIMO) OF 0.10" OF RAINFALL. && .AVIATION... VFR CONDITIONS EXPECTED TODAY...BUT A LOWERING TO MVFR TOWARD THURSDAY MORNING DUE TO SCATTERED RAIN SHOWERS UNDER LOWERING CEILINGS. && .MARINE... QUIET WITH WINDS AND SEAS FOR MOST OF FORECAST PERIOD. WINDS AND SEAS MAY INCREASE IN ADVANCE OF COLD FRONT SATURDAY AND SATURDAY NIGHT WITH SMALL CRAFT CONDITIONS POSSIBLE ESPECIALLY ALONG THE SOUTHERN OUTER WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. $$ NEAR TERM...TLM SHORT TERM...STRAUSS LONG TERM...JWD ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 950 PM EDT WED MAY 12 2004 .DISCUSSION... .SHORT TERM... 00Z RAOBS/WV LOOP AND RUC ANALYSIS SHOW WRN TROF/ERN RDG OVER NAMERICA. FAIRLY POTENT SHRTWV AND ASSOCIATED 1008MB SFC LO NOTED OVER LK WINNIPEG/JUST N OF INL...WITH SFC COLD FNT EXTENDING SW FM SFC LO TO NR DLH. COMBINATION OF THIS SHRTWV/100KT H3 JET MAX MOVING NE NR LK WINNIPEG...AXIS OF PWAT ARND 1.5 INCH STREAMING NE IN SW FLOW ALF...AND FAIRLY DEEP INSTABILITY AS SHOWN ON 00Z GRB SDNG HAS RESULTED IN BAND OF SHRA/LOCALLY SVR TSRA EARLY THIS EVNG OVER THE W AND CNTRL CWA. LEADING EDGE OF PCPN ON A MUNISING/ESC LINE AT 01Z. BUT INTENSITY OF CNVCTN DIMINISHING GREATLY AS SHRA MOVING INTO AREA OF SGNFT CIN PER SPC MESOANALSYS IN STABILIZING SLY FLOW OFF LK MI. BACK EDGE OF SHRA ON A LINE FM CMX-IMT. BUT MORE SHRA/TSRA NOTED TO THE S OVER NE WI. TO THE W...00Z MPX/INL SDNGS SHOW VERY DRY AIR ALF OVER SHARP INVRN JUST ABV H9...AND ABUNDANT LO CLD OBSVD OVER MN BEHIND COLD FNT AS VERY CHILLY AIR (SFC TEMPS IN THE 40S) UNDERCUTTING SW FLOW ALF. FAIRLY SHARP MSLP RISES OVER MN UNDER THE DEEPER SFC-H85 CAD HELPING TO PROPEL SHALLOW NR SFC COLD AIR EWD. MAIN FCST CONCERNS TNGT ARE SHRA/TSRA TRENDS AND LO TEMPS. FOR TNGT...SHRTWV/SFC LO TO THE NW PROGGED TO CONT NEWD WITH SW FLOW ALF. 00Z RUC/18Z GFS INDICATE RIBBON OF HIER H85-5 RH WL LINGER OVER THE ERN ZNS THRU THE NGT UNDER SOME UPR DVGC IN RRQ OF JET MAX LIFTING TO THE NE. DRYING ALF PROGGED TO CONT OVER THE W HALF OF FA. SO...XPCT SHRA/EMBEDDED TSRA IN NE WI TO IMPACT THE E HALF OF FA MUCH OF THE NGT. HOWEVER...HIER STABILITY THERE SHUD LIMIT COVG OF TSRA TO JUST AN ISOLD CELL OR TWO...ESPECIALLY SINCE H85 FLOW PROGGED TO GRDLY WEAKEN AND LIMIT POTENTIAL FOR ELEVATED TSRA. WL GO COMPLETELY DRY OVER THE WRN CWA AND EVEN REMOVE ANY MENTION OF SHRA THU MRNG. MIN TEMPS OVER THE E WL REMAIN RELATIVELY HI UNDER RIBBON OF PWAT AOA 1.5 INCH SINCE SFC COLD FNT FCST TO REACH ONLY MUN-MNM BY 12Z. OVER THE FAR WRN ZNS...RUC SHOWS SFC TEMPS FALLING TO THE NR 45 AT IWD...WHILE 18Z ETA INDICATES THE TEMP WL REACH 38 AT IWD. WL TEND TOWARD THE LWR ETA FCST GIVEN FAIRLY SHARP ISALLOBARIC WLY WIND COMPONENT TO THE W. KC .LONG TERM... MODELS IN BETTER AGREEMENT ON PROGRESSION OF UPPER TROF AND SLOW MOVING SFC BOUNDARY THRU THE AREA OVER THE NEXT COUPLE OF DAYS. LOOKS LIKE THE FASTER COLD FRONT DEPICTED BY PREVIOUS ETA/NGM RUNS IS NOW THE PREFERRED SOLUTION FOR TONIGHT/THU. MODELS ALSO IN GOOD AGREEMENT NOW ON DECENT WAVE LIFTING ALONG FRONT TOWARD THE STRAITS ON FRI. CHILLY RAIN/N WIND FRI (HIGH TEMPS POSSIBLY AROUND 40 AT BEST KEWEENAW/NCNTRL NEAR LAKE SUPERIOR) WILL BE A STARK CONTRAST TO TODAYS SUMMERLIKE CONDITIONS. IN THE WAKE OF FRONT...FAIRLY CONFIDENT NW/NCNTRL AREAS WILL BE DRY ON THU AS MIDLEVELS DRY AND SOME SFC RIDGING NOSES INTO THE AREA. SW/SCNTRL LESS CERTAIN AS NEXT WAVE DEVELOPS FARTHER S ALONG FRONT. HOWEVER...RIGHT ENTRANCE UPPER DIVERGENCE ASSOCIATED WITH DEVELOPING JET STREAK FROM CNTRL PLAINS TO WRN ONTARIO WILL NOT COME INTO PLAY UNTIL THU NIGHT. SO WILL TRY TO SLIP IN A DRY THERE. WILL LEAVE IN CHC POPS OVER THE E/SE THRU THE DAY DUE TO PROXIMITY OF FRONT. PREFER COOLER ETA MOS GIVEN MAGNITUDE OF COOLING BEHIND FRONT IN MN/ONTARIO (TEMPS ONLY IN THE 40S/30S) WHICH WILL BE SUSTAINED BY TRAJECTORY OVER LAKE SUPERIOR. ETA/GFS/NGM/CANADIAN MODELS ARE IN GOOD AGREEMENT ON SFC WAVE LIFTING TOWARD FAR ERN UPPER MI FRI. EXPECT A DECENT AREA OF AT LEAST LIGHT RAIN TO DEVELOP ON COOL SIDE OF WAVE THANKS TO HEALTHY UPPER DIVERGENCE UNDER RIGHT ENTRANCE REGION OF STRENGTHENING UPPER JET (120KT) FROM MN TO ONTARIO. TIMING ONSET IS STILL SOMEWHAT IN QUESTION...BUT WILL BRING IN LIKELY POPS AFTER MIDNIGHT THU NIGHT AND CARRY THRU FRI...WITH DIMINISHING TREND FRI AFTN FROM W AND SW. MOS NUMBERS ARE EXTREMELY VARIED FRI (UPWARDS OF 20 DEGREES) WITH NGM MOS AT WARM END AND ETA AT COOL END. PREFER COOLER ETA MOS GUIDANCE FOR BOTH THU NIGHT/FRI WITH N WIND AND EXPECTED RAIN. HIGH PRES STILL EXPECTED TO SETTLE OVER UPPER MI ON SAT. 850MB THERMAL TROF OVER THE AREA SHOULD RESULT IN SCT-BKN CU FOR A TIME INLAND FROM LAKE SUPERIOR BEFORE MIXING OUT. SUN THRU WED...ECMWF/UKMET/CANADIAN/GFS SHOW LESS AGREEMENT FOR THIS PERIOD THAN RUNS LOOKED AT YESTERDAY. 00Z GFS AND 12Z/11MAY ECMWF BOTH SHOWED A FAIRLY POTENT LOW PRES SYSTEM HEADING FROM THE SRN PLAINS TO GREAT LAKES MON/TUE. 06Z GFS/00Z ECMWF HAVE BACKED OFF DRAMATICALLY FROM THAT SOLUTION. THESE LATER SOLUTIONS LOOK MORE LIKE THE 00Z CANADIAN/UKMET RUNS WHICH SHOW MORE OF AN INVERTED TROF EXTENDING NE INTO THE WRN GREAT LAKES MON. WILL FAVOR THIS WEAKER SOLUTION OF AN INVERTED TROF OR JUST A WEAK LOW PRES CENTER MOVING ACROSS THE AREA MON. GOING FCST ALREADY HAS THIS COVERED WITH A CHANCE OF SHRA. PRIOR TO MON...WILL HOLD ONTO THE DRY FCST DURING THE DAY SUN WITH TROF SETTING UP W OF HERE. CONFIDENCE IS LOW THOUGH AS CANADIAN INDICATES SHRA SPREADING INTO WRN UPPER MI...AND ECMWF SUGGESTS THAT AS WELL. 12Z GFS EVEN INDICATING PCPN NOW. WILL GO WITH A DRY FCST BEHIND SYSTEM TUE/WED ALTHOUGH 00Z ECMWF SUGGESTS NEXT SHORTWAVE MAY ARRIVE AS EARLY AS WED. TEMPS THRU THE PERIOD SHOULD NOT STRAY TOO FAR FROM NORMALS. ROLFSON && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 930 PM EDT WED MAY 12 2004 .UPDATE... AT 0115Z THE KGRR 88D SHOWS SCATTERED SHOWERS AND AN ISOLATED EMBEDDED THUNDERSTORM JUST NW OF GRR. THE BROKEN LINE OF SHOWERS EXTENDS FARTHER NORTH ALONG THE US-131 CORRIDOR TO BIG RAPIDS AND SOUTH OF CAD. A LARGER AREA OF RAIN WITH EMBEDDED THUNDERSTORMS IS NOTED ACROSS CENTRAL AND SOUTHERN LAKE MI. MOST OF THE LIGHTNING IS OCCURRING ACROSS SOUTHERN LAKE MI. ADDITIONAL SHOWERS AND TSTORMS ARE NOTED ACROSS MUCH OF IL AND WI. SHOWERS AND TSTORMS WILL GRADUALLY OVERSPREAD OUR AREA LATE TONIGHT AS THE COLD FRONT MOVES EAST INTO CENTRAL WI AND THE FOCUS OF ALL CONVECTION SHIFTS FARTHER EAST. SEVERE WX IS VERY UNLIKELY OVERNIGHT. WIND FIELDS WITH HEIGHT ARE FAIRLY LIGHT, FREEZING LEVELS ARE UP AROUND 12.5 KFT... AND WE ARE LOSING INSTABILITY GENERATED FROM DAYTIME HEATING. HOWEVER, THE RUC 500 CHART SHOWS CLUSTERS OF STORMS IN IL ARE DEVELOPING IN PVA DOWNSTREAM OF THE STRONG IMPULSES OF H5 ENERGY... ALL OF WHICH SHIFTS NE INTO OUR AREA LATE TONIGHT. PW VALUES WILL CONTINUE TO GRADUALLY RISE TO AROUND 1.5" OR HIGHER BY 12Z THUR. THEREFORE, THOUGH SEVERE WX IS UNLIKELY, ANY OF THESE STORMS MAY CERTAINLY PRODUCE SOME HEAVY RAIN, ESPECIALLY DURING THE EARLY MORNING HOURS THURSDAY. WE WILL DEFINITELY NEED TO WATCH FOR ANY FURTHER POTENTIAL HYDRO CONCERNS AND MONITOR RIVER TRENDS. HAVING SAID ALL THIS, OUR GOING FORECAST LOOKS QUITE GOOD. WE'LL JUST TWEAK WORDING A BIT FOR TIMING OF CONVECTION INTO OUR AREA, AND FOR OVERNIGHT FORECAST WORDING. && .GRR...WATCHES/WARNINGS/ADVISORIES...NONE. && LAURENS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 510 PM EDT WED MAY 12 2004 .DISCUSSION... MAIN FCST CONCERNS ARE SVR TSRA POTENTIAL TONIGHT...WHETHER POPS ARE NEEDED THU AND TEMPS/POPS FRI. WATER VAPOR IMAGERY/RUC ANALYSIS SHOW TROF PERSISTING OVER THE ROCKIES WITH RIDGE OVER THE SE CONUS. ONE PROMINENT SHORTWAVE WAS LIFTING OUT OF TROF THRU ERN DAKOTAS/NW MN WHILE ANOTHER HAS JUST ROUNDED BASE OF TROF AND WAS LIFTING THRU COLARADO. SFC LOW PRES WAS LOCATED IN NE MN WITH TRAILING COLD FRONT JUST ENTERING WRN WI. LINE OF SHRA/TSRA HAS REDEVELOPED ALONG/AHEAD OF FRONT WITH OTHER STORMS DEVELOPING FARTHER E IN CAPLESS/UNSTABLE ENVIRONMENT (SBCAPE UPWARDS OF 2-2.5K J/KG OVER WRN UPPER MI). DEFINITELY A SUMMERLIKE FEEL THIS AFTN WITH MANY AREAS OVER THE W HALF OF UPPER MI WELL INTO THE 70S/MID 80S WITH DWPTS AROUND 60F. QUITE A DAY IN ONTONAGON AS TEMP HIT 84 AROUND 1730Z AND THEN DROPPED TO 43 AS WIND SHIFTED OFF THE LAKE. MODELS IN BETTER AGREEMENT ON PROGRESSION OF UPPER TROF AND SLOW MOVING SFC BOUNDARY THRU THE AREA OVER THE NEXT COUPLE OF DAYS. LOOKS LIKE THE FASTER COLD FRONT DEPICTED BY PREVIOUS ETA/NGM RUNS IS NOW THE PREFERRED SOLUTION FOR TONIGHT/THU. MODELS ALSO IN GOOD AGREEMENT NOW ON DECENT WAVE LIFTING ALONG FRONT TOWARD THE STRAITS ON FRI. CHILLY RAIN/N WIND FRI (HIGH TEMPS POSSIBLY AROUND 40 AT BEST KEWEENAW/NCNTRL NEAR LAKE SUPERIOR) WILL BE A STARK CONTRAST TO TODAYS SUMMERLIKE CONDITIONS. ETA IS JUST A TOUCH FASTER THAN GFS WITH MOVEMENT OF FRONT TONIGHT...AND WILL LARGELY FOLLOW ETA TIMING WITH ITS RECENT CONSISTENCY. FRONT SHOULD BE NEAR/JUST E OF KERY BY 12Z THU. AS FOR SVR TSRA THREAT...PLENTY OF SFC BASED INSTABILITY PRESENT ATTM (2-2.5K J/KG). HOWEVER...0-6KM SHEAR IS ONLY ON THE ORDER OF 20-30KT WHICH WILL WORK TO LIMIT SVR THREAT. NONETHELESS...POTENTIAL IS THERE FOR BRIEF ISOLD SVR STORMS (SVR HAIL/DAMAGING WIND) THIS EVENING BEFORE INSTABILITY DIMINISHES. WILL CONTINUE TO CARRY CATEGORICAL POPS E WITH FRONT AS THERE IS A BRIEF BOUT OF UPPER DIVERGENCE ASSOCIATED WITH JET STREAK LIFTING TO ONTARIO THAT SHOULD MAINTAIN SHRA/TSRA THRU THE NIGHT. IN THE WAKE OF FRONT...FAIRLY CONFIDENT NW/NCNTRL AREAS WILL BE DRY ON THU AS MIDLEVELS DRY AND SOME SFC RIDGING NOSES INTO THE AREA. SW/SCNTRL LESS CERTAIN AS NEXT WAVE DEVELOPS FARTHER S ALONG FRONT. HOWEVER...RIGHT ENTRANCE UPPER DIVERGENCE ASSOCIATED WITH DEVELOPING JET STREAK FROM CNTRL PLAINS TO WRN ONTARIO WILL NOT COME INTO PLAY UNTIL THU NIGHT. SO WILL TRY TO SLIP IN A DRY THERE. WILL LEAVE IN CHC POPS OVER THE E/SE THRU THE DAY DUE TO PROXIMITY OF FRONT. PREFER COOLER ETA MOS GIVEN MAGNITUDE OF COOLING BEHIND FRONT IN MN/ONTARIO (TEMPS ONLY IN THE 40S/30S) WHICH WILL BE SUSTAINED BY TRAJECTORY OVER LAKE SUPERIOR. ETA/GFS/NGM/CANADIAN MODELS ARE IN GOOD AGREEMENT ON SFC WAVE LIFTING TOWARD FAR ERN UPPER MI FRI. EXPECT A DECENT AREA OF AT LEAST LIGHT RAIN TO DEVELOP ON COOL SIDE OF WAVE THANKS TO HEALTHY UPPER DIVERGENCE UNDER RIGHT ENTRANCE REGION OF STRENGTHENING UPPER JET (120KT) FROM MN TO ONTARIO. TIMING ONSET IS STILL SOMEWHAT IN QUESTION...BUT WILL BRING IN LIKELY POPS AFTER MIDNIGHT THU NIGHT AND CARRY THRU FRI...WITH DIMINISHING TREND FRI AFTN FROM W AND SW. MOS NUMBERS ARE EXTREMELY VARIED FRI (UPWARDS OF 20 DEGREES) WITH NGM MOS AT WARM END AND ETA AT COOL END. PREFER COOLER ETA MOS GUIDANCE FOR BOTH THU NIGHT/FRI WITH N WIND AND EXPECTED RAIN. HIGH PRES STILL EXPECTED TO SETTLE OVER UPPER MI ON SAT. 850MB THERMAL TROF OVER THE AREA SHOULD RESULT IN SCT-BKN CU FOR A TIME INLAND FROM LAKE SUPERIOR BEFORE MIXING OUT. SUN THRU WED...ECMWF/UKMET/CANADIAN/GFS SHOW LESS AGREEMENT FOR THIS PERIOD THAN RUNS LOOKED AT YESTERDAY. 00Z GFS AND 12Z/11MAY ECMWF BOTH SHOWED A FAIRLY POTENT LOW PRES SYSTEM HEADING FROM THE SRN PLAINS TO GREAT LAKES MON/TUE. 06Z GFS/00Z ECMWF HAVE BACKED OFF DRAMATICALLY FROM THAT SOLUTION. THESE LATER SOLUTIONS LOOK MORE LIKE THE 00Z CANADIAN/UKMET RUNS WHICH SHOW MORE OF AN INVERTED TROF EXTENDING NE INTO THE WRN GREAT LAKES MON. WILL FAVOR THIS WEAKER SOLUTION OF AN INVERTED TROF OR JUST A WEAK LOW PRES CENTER MOVING ACROSS THE AREA MON. GOING FCST ALREADY HAS THIS COVERED WITH A CHANCE OF SHRA. PRIOR TO MON...WILL HOLD ONTO THE DRY FCST DURING THE DAY SUN WITH TROF SETTING UP W OF HERE. CONFIDENCE IS LOW THOUGH AS CANADIAN INDICATES SHRA SPREADING INTO WRN UPPER MI...AND ECMWF SUGGESTS THAT AS WELL. 12Z GFS EVEN INDICATING PCPN NOW. WILL GO WITH A DRY FCST BEHIND SYSTEM TUE/WED ALTHOUGH 00Z ECMWF SUGGESTS NEXT SHORTWAVE MAY ARRIVE AS EARLY AS WED. TEMPS THRU THE PERIOD SHOULD NOT STRAY TOO FAR FROM NORMALS. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1100 AM EDT WED MAY 12 2004 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST UPDATE IS THE THUNDERSTORM POTENTIAL FOR THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A LONGWAVE TROUGH OVER THE THE NORTHERN HIGH PLAINS AND A RIDGE OVER THE UPPER GREAT LAKES. SURFACE ANALYSIS DEPICTS A DEEP LOW OVER NORTHERN MINNESOTA WITH A WARM FRONT STRETCHING EAST THROUGH NORTHERN LAKE SUPERIOR INTO SOUTHEAST ONTARIO...AND A COLD FRONT DRAPED SOUTHWEST INTO NORTHEAST KANSAS. THE COLD FRONT IS DIRECTING LOW LEVEL GULF MOISTURE INTO THE UPPER MISSISSIPPI RIVER VALLEY. SURFACE DEW POINTS OVER WISCONSIN AND MINNESOTA HAVE CLIMBED INTO THE MID 60S. OVERRUNNING OF THE WARM FRONT AND INSTABILITY ACCOMPANYING THE SHORTWAVE MOVING THROUGH THE UPPER LEVEL RIDGE ARE GENERATING SCATTERED SHOWERS AND THUNDERSTORMS OVER EAST CENTRAL AND NORTHEAST MINNESOTA. SCATTERED RAIN SHOWERS AND THUNDERSTORMS DEVELOPED THIS MORNING ALONG THE NORTHERN LAKE MICHIGAN SHORE IN ASSOCIATION WITH WEAK 850-500MB Q-VECTOR CONVERGENCE AND AREA OF THE HIGHEST CAPE VALUES. AS THE CAPE VALUES DIMINISH THE THUNDERSTORMS ENDED...HOWEVER A FEW SHOWER PERSIST. RUC/ETA SHOWING A LOW DEVELOPING WITHIN THE LONGWAVE TROUGH AND OVER SOUTHWEST SASKATCHEWAN THIS AFTERNOON. SHORTWAVE ENERGY SWINGING THROUGH THE TROUGH WILL REACH THE EASTERN DAKOTAS AND NORTHWEST MINNESOTA. LOW LEVEL MOISTURE WILL CONTINUE TO BE DIRECTED INTO THE UPPER GREAT LAKES REGION WITH THE HIGHEST RELATIVE HUMIDITIES OVER NORTHWEST WISCONSIN. RUC/ETA BOTH SHOW AN INCREASE IN Q-VECTOR CONVERGENCE OVER THE WESTERN U.P. AND BY 18Z MOST UNSTABLE CAPE WILL INCREASE TO >1000 J/KG OVER THE WEST END AND AROUND 800 J/KG OVER THE CENTRAL U.P. BY LATE AFTERNOON...THE CAPE VALUES AND Q-VECTORS WILL INCREASE CONSIDERABLY ACROSS THE FORECAST AREA. LIFTED INDICES AND CAPE POINT TO THE GREATEST POTENTIAL OF THUNDERSTORM DEVELOPMENT WILL BE OVER NORTH CENTRAL WISCONSIN THIS AFTERNOON WHERE MUCAPE ARE PROGGRED TO >2500J/KG AND LI'S < -4. HOWEVER...THAT COULD MEAN THAT THE STORMS WILL DEVELOP THERE AND MOVE INTO THE FORECAST AREA BE DISSIPATING. THIS WILL NEED CLOSE MONITORING THROUGH THE AFTERNOON. THE MID LEVEL RIDGE WILL SHIFT TO EASTERN ONTARIO THIS EVENING AS A WEAK SHORTWAVE SHIFT INTO THE WESTERN U.P. THE SURFACE LOW WILL SHIFT INTO WESTERN ONTARIO BY 00Z AND INTO NORTHERN ONTARIO OVERNIGHT...ALL THE WHILE DRAGGING THE COLD FRONT INTO CENTRAL U.P. THE MUCAPE VALUES WILL INCREASE TO >1000J/KG THIS EVENING. AS THE SURFACE HEATING DIMINISHES OVERNIGHT THE MUCAPE VALUES WILL SHIFT EAST AND DIMINISH AS WELL. WILL LEAVE THE OVERNIGHT FORECAST ALONE AND IT LOOKS REASONABLE AT THIS TIME. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON MS 646 PM CDT WED MAY 12 2004 .UPDATE...LATEST SATELLITE AND RADAR IMAGERY SHOW A WEAKENING MCS TO THE SOUTH OF THE FORECAST AREA. THUNDERSTORM OUTFLOW FROM IT...ALONG WITH A DENSE CIRRUS SHIELD HAVE HELPED KEEP THE ATMOSPHERE RELATIVELY STABLE IN AREAS SOUTH OF INTERSTATE 20 FOR MOST OF THE AFTERNOON AND EVENING. (AREAS NORTH OF INTERSTATE 20 HAVE SEEN SOME MARGINAL INSTABILITY.) THE ONLY MODEL THAT APPEARS TO BE HANDLING THE CURRENT SITUATION WELL IS THE RUC WHICH OFFERS THE FOLLOWING SOLUTION. THE MCS TO THE SOUTH SHOULD CONTINUE TO WEAKEN AS IT SLOWLY PROPAGATES EAST. AS IT DOES SO...PRECIP SHOULD GRADUALLY TAPER OFF. MEANWHILE TO THE NORTH...A WAVE WILL CONTINUE TO MOVE THROUGH NORTHERN MISSISSIPPI. PRECIP NORTH OF INTERSTATE 20 SHOULD CONTINUE TO MOVE EAST WITH THE WAVE...WITH AREAS EAST OF INTERSTATE 55 SEEING THE MOST RAIN. HAVE UPDATED THE ZONES TO DECREASE POPS IN THE WESTERN AREAS. && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && 18/HENRY ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 1125 AM EDT WED MAY 12 2004 .DISCUSSION... .UPDATE...ONLY MINOR CHANGES TO CURRENT WEATHER FIELDS BASED ON CURRENT WEATHER AND TRENDS. WE UPPED TEMPS OVER LONG ISLAND AND HAVE ADDED STRATUS/FOG FOR WATERS TONIGHT. RIDGE REMAINS OVER REGION WITH DIFFUSE FRONTAL BOUNDARY OVER THE AREA. WATER VAPOR IMAGERY AND LATEST RUC MODEL RUN INDICATES A VERY WEAK SHORTWAVE OVER CENTRAL PA. CLOUDS ALSO IN THIS AREA CURRENTLY. MODELS INDICATE A FAIR AMOUNT OF SURFACE HEATING INSTABILITY WITH 2000+ J/KG OF SURFACE BASED CAPE AND -5 C ON THE LI. EXPECT MORE ACTIVITY THAN YESTERDAY WITH FOCUS OF CONVECTION BEING TO THE NORTHWEST OF NYC AND THEN A DRIFT TO THE EAST SOUTHEAST. HIGH PW AND SLOW MOVING CONVECTION INDICATES GOOD POTENTIAL FOR URBAN FLOODING. KEEPING POPS AS AND DO NOT ANTICIPATE THE FORMATION OF AN MCS AS WE HAD MONDAY NIGHT. && .AVIATION...EXPECT MVFR HAZE...THOUGH SURFACE OBS WILL LIKELY REACH P6SM WITH MIXING. HAZE ALOFT WILL CONTINUE. MODERATE AMOUNTS INSTABILITY ARE PRESENT IN THE ATMOSPHERE FOR WIDELY SCATTERED AFTERNOON/EARLY EVENING THUNDERSTORMS. EXPECT THESE TO ME FOCUSED TO THE NORTH AND WEST OF NYC. RIGHT NOW NOT EXPECTING A SIGNIFICANT IMPACT ON THE TERMINAL. ONLY HAVE TEMPO GROUP FOR SWF WITH VCNTY FOR LGA-EWR-TEB-HPN. EXPECT SEA BREEZE CONVERGENCE KEEPS ACTIVITY OUT OF JFK WITH A CLOSE CALL FOR EWR AND LGA...BUT MAINLY NORTHWEST OF THE TERMINAL. && ************* PREVIOUS 415 AM DISCUSSION ************************** SHORT TERM... THU AND THU NIGHT...AN EASTERLY FLOW BEGINS TO DEVELOP ON THU. MEANWHILE...THE UPPER LEVEL RIDGE REMAINS IN PLACE ALTHOUGH IT STARTS TO MOVE SLOWLY TO THE E TOWARD EVENING. FOR THU...I/LL KEEP THE POPS SIMILAR TO TODAY/S. HOWEVER...A TROF APPROACHES FROM THE SW THU NIGHT AS THE UPPER RIDGE MOVES A LITTLE TO THE E. I/LL INCR THE POPS FOR THU NIGHT...IN LINE WITH THE ETA AND GFS. FRI...I/LL FORECAST CHANCE POPS AS THE SW FLOW ALOFT CONTINUES. LONG TERM...NO SIG CHANGES...OTHER THAN TO ADD POPS FOR FRI NIGHT. && .MARINE...RELATIVELY QUIET THROUGH FRIDAY NIGHT. MAIN CHANGE TO PREVIOUS FORECAST FROM THU-FRI AS HIGH PRESSURE BUILDING SE INTO NEW ENGLAND TURNS WINDS EASTERLY THU AFTERNOON AND NIGHT...THEN SE-S ON FRI AS THE HIGH MOVES WELL E OF THE NEW ENGLAND COAST. SCA FOR ROUGH OCEAN SEAS POSSIBLE BEGINNING SAT MORNING WITH INCREASING SW FLOW AHEAD OF APPROACHING COLD FRONT. && .HYDROLOGY...SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE...BUT NO WIDESPREAD PROBLEMS EXPECTED FOR THE NEXT COUPLE OF DAYS. && ***************** END OF PREVIOUS FORECAST ************************ .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NJ...NONE. NY...NONE. MARINE...NONE. && $$ TONGUE ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 945 AM EDT WED MAY 12 2004 .DISCUSSION... RUC HAS A GGOD HANDLE ON OMEGA/PRECIPITATION BULLSEYE THIS MORNING. MODELS CONTINUE TO SHOW ACTIVITY ALONG THE SEABREEZE TODAY. WEAK INSTABILITY COUPLED WITH WEAK SHORT WAVE WILL BE ENOUGH FOR SHOWERS AND THUNDERSTORMS TODAY WITH PRECIPITABLE WATERS 1 TO 1 1/2". WILL TWEAK CURRENT FORECAST TO INCREASE POPS SLIGHTLY...MAINLY INLAND FROM THE BEACHES. REMAINDER OF THE FORECAST LOOKS TO BE ON TARGET FOR THIS AFTERNOON. && .MARINE... VERY QUITE OVER THE WATERS THIS MORNING WITH SOUTHERLY WINDS AROUND 8 KNOTS REPORTED AT 41013 WITH 3 FT SEAS. THE 06Z MESO-ETA SHOWING SOUTHERLY WINDS CONTINUING WITH SPEEDS REMAINING AROUND 10 KNOTS THROUGH THE DAY. GFS BUFR SOUNDING SHOWING WINDS ALONG THE COAST REACHING 11 KNOTS AT KILM AROUND 18Z. SO PLANS ARE ONLY TO MODIFY THE WIND SPEED TO AROUND 10 KNOTS FOR AFTERNOON FORECAST && .PRELIMINARY POINT TEMPS/POPS... WILMINGTON 83 64 83 65 / 20 20 10 10 FLORENCE 84 62 84 63 / 30 20 10 10 LUMBERTON 84 62 84 63 / 30 20 10 10 MYRTLE BEACH 80 65 79 66 / 20 20 10 10 && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. && $$ PUBLIC: RJD MARINE: HAWKINS nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 939 PM EDT WED MAY 12 2004 .UPDATE... REGIONAL RADAR COMPOSITE SHOWING MCS DRIFTING SLOWLY NORTH ACROSS CENTRAL AND NORTH GA THIS EVENING. CORFIDI VECTORS SHOW A VERY WEAK TREND TO THE EAST. OVER THE PAST HALF HOUR...LIGHTNING COUNTS HAVE DROPPED AND WOULD EXPECT CONVECTION TO CONTINUE TO DECREASE AS THE COMPLEX MOVES NORTH. HOWEVER...WITH PERSISTENT SOUTH LLVL FLOW AND POSSIBLE ASSOCIATED WEAK VORT WILL EXPECT SOME OF THE CONVECTION TO MAINTAIN IT/S SELF OVER THE ESCARPMENT FOR THE REST OF THE NIGHT. IN FACT...BOTH THE ETA AND THE RUC PAINT QPF ACROSS THE UPSLOPE AREAS TONIGHT. WILL INCREASE POPS OVER EXTREME NE GA AND PROLONG COVERAGE OVER THE HIGHER TERRAIN. WILL MAKE MINOR TWEAKS TO THE TEMPS FIELDS. WILL CONTINUE THE MENTION OF FOG. MESOETA LLVL MOISTURE IS THE GREATEST OVER THE MIDLANDS AND EAST...WITH EXPECTED RAINFALL WILL NOT MENTION DENSE FOG. && .PREV DISCUSSION... CURRENT WV IMAGERY INDICATES WEAK SW TROUGH CONTINUES TO LIFT SLOWLY NORTHEAST ACROSS THE SOUTHERN PIEDMONT AND MIDLANDS. ALTHOUGH THE SMALL MCS FORCED BY THIS WAVE HAS LARGELY DISSIPATED...A MODERATELY UNSTABLE AIRMASS IS RESULTING IN GOOD COVERAGE OF CONVECTION ACROSS THE SOUTHEAST 1/4 OF THE CWFA...ALONG AND AHEAD OF THE TROUGH AXIS. TO THE NORTH AND WEST...CONVECTIVE COVERAGE IS ISOLATED TO WIDELY SCATTERED AT THIS TIME. AS THE WAVE CONTINUES TO DRIFT NORTHEAST...BETTER COVERAGE OF PRECIP SHOULD SHIFT NORTHEAST OF THE AREA...BUT WE WILL CARRY A LIKELY POP ACROSS THE SOUTHEAST ZONES THROUGH ABOUT 00Z...THEN CHANCE POPS THROUGH LATE EVENING. A STRONGER SW TROUGH OVER THE MISS VALLEY IS CURRENTLY FORCING A RATHER LARGE AND SLOW-MOVING MCS ACROSS THE GULF COAST STATES. AS A CONSEQUENCE OF THIS FEATURE...THE GFS INDUCES A RATHER POTENT MCV ACROSS THE TENN VALLEY LATE TONIGHT...AND BRINGS THE REMNANT MCS ACROSS OUR MOUNTAIN ZONES TOMORROW MORNING. MEANWHILE...THE ETA INDICATES THE SHORT WAVE RESPONSIBLE FOR THIS CONVECTION WILL DAMPEN AS IT LIFTS WELL NORTHWEST OF THE AREA. THIS RESULTS IN THE VAST MAJORITY OF MODEL QPF REMAINING TO OUR WEST. HAVE A COUPLE OF CONCERNS ABOUT THE GFS...NOT THE LEAST OF WHICH IS THE OBVIOUS GRID SCALE FEEDBACK PROBLEMS RESULTING FROM ITS SPURIOUS QPF BOMBS. IN ADDITION... CONSIDERING THE BACK-BUILDING NATURE OF THIS MCS...FEEL THAT THE MODEL IS MUCH TOO FAST WITH ITS EASTWARD DEVELOPMENT. THEREFORE...HAVE SIDED CLOSELY WITH THE ETA FOR THIS PACKAGE. IN OTHER WORDS...A MOIST BUT WEAKLY FORCED ATMOSPHERE WILL RESULT IN CHANCES FOR MAINLY DIURNAL CONVECTION THROUGH THE SHORT TERM PERIODS. A STRONG SW TROUGH TRAVERSING THE PLAINS WILL SEND A FRONTAL BOUNDARY TOWARD THE REGION SATURDAY. THIS FNT MOVES INTO THE CWFA SUNDAY THEN RETURNS NORTH MONDAY. CONVECTION CHANCES BEST THESE TWO DAYS WITH INCREASED MOISTURE AND LOW LEVEL CONVERGENCE. SFC RIDGING BUILDS BACK IN TUE AND HOLDS ON WED AS ANOTHER FNT SLOWLY SAGS SWD TOWARD THE AREA. LOW CHC FOR CONVECTION THESE TWO DAYS...BUT HELD ON TO SILENT 20 POP AS WE ARE SURROUNDED BY AREAS WITH BETTER CHC. TEMPS REMAIN ABOVE NORMAL...BUT COOLER THAN PREV FCST ESP SUNDAY WITH FRONT INTO THE CWFA. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ NED sc AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 830 PM CDT WED MAY 12 2004 .DISCUSSION... COUPLE OF THINGS OF CONCERN FOR THIS EVNG THRU EARLY THURS MRNG. FIRST IS SCTD TSRA CREEPING INTO FAR SERN ZONES IN NW IA. LATEST RUC SHOWS TSRA FM SERN NE THRU CNTRL IA TO CONT ALONG MID LVL FNT. THIS HAS LIFTED JUST FAR ENUF N TO BRING WDLY SCTD TSRA INTO FSD CWA. THESE WL CONT FOR A COUPLE MORE HOURS BEFORE SHIFTING BACK TO THE ESE. HAVE UPDATED GRIDS TO COVER THIS AND ISSUED NOW. SECOND CONCERN IS CHC FOR SNOW LATE TNGT THRU ERLY THURS AM. 18Z MESOETA AND GFS SNDGS SHOW A NARROW BAND WHERE TEMPS ARE COLD ENUF WITH SUFFICIENT LIFT AND SATURATION FOR MEASURABLE SNOW. THIS BAND LOOKS TO BE FM CHARLES MIX CNTY THRU KMHE-KBKX LINE. WL WAIT FOR 00Z MODELS TO TAKE A CLOSER LOOK AT WHAT CHANGES NEED MADE THRU THURS MRNG. LOOK FOR UPDATED ZFP BETWEEN 0230-0300Z. && .FSD...WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ MG sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 832 PM CDT WED MAY 12 2004 .DISCUSSION... WILL NEED AN UPDATE THIS EVENING TO LOWER POPS...MAINLY ACROSS WESTERN HALF OF CWA. VORT AXIS ON WATER VAPOR AND RUC...HAS MOVED ACROSS ABOUT 2/3RDS OF THE CWA...ALONG A PAH-TUP LINE AT 01Z. MOST WIDESPREAD RAIN HAS MOVED OUT OF CWA. PLAN TO DROP MENTION WEST OF MISSISSIPPI RIVER...AND WESTERN HALF OF NORTH MISSISSIPPI. PROBABLY WILL GO ABOUT 30 POPS ELSEWHERE. NO REAL REASON TO MESS WITH OVERNIGHT TEMPERATURES AT THIS POINT. WILL ISSUE UPDATE BEFORE 0200Z...AND MAY NEED ANOTHER ONE IF ALL PRECIP MOVES OUT OF THE AREA BEFORE MIDNIGHT. && .MEG...WATCHES/WARNINGS/ADVISORIES... AR...NONE. MS...NONE. MO...NONE. TN...NONE. && $$ WAGNER tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 245 PM CDT WED MAY 12 2004 .SHORT-TERM (TONIGHT THROUGH THURSDAY NIGHT)...CLOUDS HAVE BEEN RELUCTANT TO BURN OFF TODAY ACROSS SOUTH TEXAS. THIS AND LIGHT SHOWERS REMAINING BELOW THE CAP HAS PRETTY MUCH KEPT TEMPS IN CHECK. WV IMAGERY SHOWING SHORTWAVE MOVING ACROSS NORTH-CENTRAL MEXICO AT THIS TIME. THIS FEATURE LOOKS LIKE ITS BEGINNING TO SHEAR OUT BUT MAY STILL PROVIDE SOME LIFT ACROSS THE REGION TONIGHT. BEST DYNAMICS FROM THIS FEATURE SHOULD ARRIVE BETWEEN MIDNIGHT AND 6 AM. RUC ANALYSIS IS ALSO SHOWING AN 80 KT JET CORE APPROACHING DEEP SOUTH TEXAS THIS EVENING...PUTTING OUR CWA IN THE LEFT FRONT QUADRANT. MODEL SOUNDINGS ARE SHOWING FAIRLY STEEP LAPSE RATES ABOUT 800 HPA THIS EVENING PRODUCING SOME ELEVATED CAPE. LLJ WILL ALSO CRANK UP TONIGHT WITH WINDS OF 40KT PROGGED AT 925 HPA. THIS WILL HELP INCREASE THE SHEAR ACROSS THE AREA AS WELL. WILL GO AHEAD AND KEEP 20 PERCENT RAIN CHANCES ACROSS THE NORTHERN TIER COUNTIES TONIGHT. EXPECT SCA CONDITIONS TO OCCUR THIS EVENING OVER THE OFFSHORE WATERS AS THE LLJ INCREASES. SHOULD DROP DOWN TO SCEC OVER THE BAYS. TOMORROW SHOULD BE SOMEWHAT QUIET LIKE TODAY...WITH DEPARTING SHORTWAVE LEAVING THE CWA IN A PERIOD OF SUBSIDENCE. WILL PUT LOW END CHANCE POPS ACROSS THE NORTHEAST TOMORROW TO ACCOUNT FOR THE POSSIBILITY OF SOME LIGHT/MODERATE SHOWERS AND THUNDERSTORMS. THE BEST SURFACE CONVERGENCE LOOKS TO BE TO THE EAST OF INTERSTATE 37. SLIGHT CHANCE POPS SHOULD SUFFICE ELSEWHERE. TEMPS TOMORROW SHOULD BE A FEW DEGREES WARMER THAN TODAY ACROSS MUCH OF THE AREA. WILL BLANKET 30 POPS ACROSS THE CWA THURSDAY NIGHT AHEAD OF THE NEXT UPPER-LEVEL SYSTEM AND ASSOCIATED SURFACE FRONT. THIS PERIOD WILL NEED TO BE WATCHED FOR FUTURE UPDATES AS THE TIMING BECOMES MORE CLEAR. && LONG-TERM (FRIDAY THROUGH WEDNESDAY)...RAIN CHANCES INCREASE THROUGH FRI AS THE MAIN TROF AXIS APPROACHES THE REGION AND A COLD FRONT SINKS SOUTHWARD INTO CENTRAL TX. AGREE WITH PREVIOUS SHIFT THAT...DEVELOPMENT OF AN MCS OVR N TX THU NIGHT ASSOC WITH THE COLD FRONT...WILL HELP PROPAGATE THE CF SOUTHWARD FASTER...OR AT LEAST OUTFLOW BOUNDARY/PSEUDO FRONT AFFECTING THE CWA BY FRI MORNING. MODELS INDICATE THE WIND SHIFT OR ACTUAL CF FRI NIGHT. LATEST MODEL SOLNS HAVE FRONT THRU THE CWA BY SAT MORNING THEN QUICKLY RETREATING N BY LATE SAT. THUS...WHERE THE CF ACTUALLY STALLS BEFORE RETREATING N IS UNCERTAIN...BUT FEEL IT WILL BE IN CLOSE PROXIMITY TO THE CWA. THIS WILL PROVIDE FOCUS FOR CONTD PRECIP AT LEAST FOR SAT MORNING BEFORE WINDS SHIFT BACK TO THE SE. ALSO OF NOTE...THE GFS SPLITS THE HEAVIEST PRECIP FRI EVENING...WITH PART OF IT MOVING MORE TOWARD E TX/LA IN RESPONSE TO THE UPPER LEV DYNAMICS SHIFTING NE AND THE OTHER PIECE MOVING SW TOWARD THE RIO GRAND AND MEX IN RESPONSE TO ANOTHER S/WV MOVG ACROSS MEX. DUE TO UNCERTAINTIES IN MODEL SOLNS...WILL LET LATER SHIFTS FINE TUNE POPS/LOCATION OF HEAVIEST RAINFALL FOR FRI AND SAT. RAIN CHCS TAPER OFF SUN/MON AS A RIDGE BLDS ACROSS THE REGION. MODELS INDICATE DISTURBANCES IN NW FLOW ALOFT SUN/MON WHICH...COMBINED WITH SFC FORCING/SEA BREEZE...WILL MAINTAIN A SLIGHT CHC OF PRECIP. WILL KEEP TUE/WED DRY WITH 5 TO 10 PERCENT POPS. && .TEMPERATURES AND WIND...THE COLD FRONT WILL BRING SLIGHTLY COOLER TEMPS FOR SAT MORNING. SE FLOW QUICKLY RETURNS LATE SAT WITH TEMPS REBOUNDING. ONSHORE FLOW RELAXES ON FRI AS THE COLD FRONT MOVES SOUTH ACRS TX. HOWEVER...WINDS COULD ACTUALLY INCREASE FRI DEPENDING ON DVLPMNT/STRENGTH OF MCS. WINDS EXPECTED TO SHIFT NE FRIDAY EVENING AND REMAIN BELOW SCEC THROUGH SAT DUE TO CF STALLING IN VCNTY OF CWA. ONSHORE FLOW QUICKLY RETURNS LATE SAT BUT IS EXPECTED TO REMAIN BELOW SCA CRITERIA THRU NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 76 85 74 84 69 / 10 20 30 60 50 VICTORIA 74 85 72 82 66 / 20 30 30 60 50 LAREDO 77 94 75 86 67 / 20 20 30 50 50 ALICE 75 90 73 85 67 / 10 20 30 60 50 ROCKPORT 76 84 74 81 70 / 20 30 30 60 50 COTULLA 73 91 72 84 65 / 20 20 30 50 40 && .CRP WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY FOR THE THE BAY WATERS. && $$ 94/MJ...SHORT-TERM 81/TE...LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1015 AM CDT WED MAY 12 2004 .UPDATE...ISOLATED LIGHT SHOWERS WERE LOCATED ALONG THE NORTHERN COASTAL BEND TO THE VICTORIA THIS MORNING BUT ONLY TRACE AMOUNTS ARE EXPECTED WITH THIS. 12Z KCRP SOUNDING IS SHOWING PWAT VALUES UP TO 1.58 INCHES WITH A SMALL CAP AROUND 800 HPA. THERE ARE GOOD LAPSE RATES ABOVE THIS CAP FROM 800-650 HPA BUT LACK OF DYNAMICS WILL LIKELY KEEP THIS INSTABILITY FROM BEING PUT TO USE. WITH THIS IN MIND...WILL CONTINUE TO KEEP ONLY MENTION OF ISOLATED ACTIVITY IN THE ZONES FOR THE INLAND LOCATIONS TODAY. TEMP FORECAST LOOKS ON TRACK WITH READINGS IN THE MID 90S ACROSS THE RIO GRANDE PLAINS AND MID 80S IN THE EAST. FORECAST FOR TONIGHT LOOKS INTERESTING HOWEVER. VORTICITY MAXIMUM SHOWING UP IN WV IMAGERY OVER THE BAJA IS NOT INITIALIZED WELL ON THE 6Z MODEL RUNS. RUC ANALYSIS IS SHOWING THIS SHORTWAVE BUT DOES NOT HAVE A HANDLE ON ITS MOTION. TIMING FOR THIS FEATURE TO MOVE ACROSS SOUTH TEXAS LOOKS TO BE BETWEEN MIDNIGHT AND 12Z. WITH MOISTURE IN PLACE AT THE SURFACE AND ONLY A WEAK CAP...THINK THAT POPS MAY NEED TO BE BUMPED UP TO AT LEAST 20 PERCENT TONIGHT ACROSS THE AREA...MAYBE TO LOW END CHANCE ACROSS THE NORTH. WILL MONITOR THE 12Z MODEL RUNS AS THEY COME IN TO SEE HOW THIS FEATURE IS HANDLED. SCEC CONDITIONS WILL CONTINUE OVER THE BAYS AND GULF WATERS TODAY...BUT WILL HAVE TO KEEP AN EYE ON THE OFFSHORE WATERS. THE SEAS HAVE CREPT UP TO 6 FEET AND WINDS ARE GETTING CLOSE TO SCA CONDITIONS. DO EXPECT SCA FLAG TONIGHT IN THE GULF BUT MAY HAVE TO UPDATE THE FORECAST TO FLAG THE WATERS A LITTLE SOONER THIS AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 86 75 85 72 84 / 05 10 30 30 60 VICTORIA 86 73 84 71 80 / 10 10 40 30 60 LAREDO 96 77 93 71 87 / 10 10 20 40 50 ALICE 91 74 89 72 85 / 10 10 30 30 60 ROCKPORT 83 76 83 74 82 / 05 20 40 30 60 COTULLA 93 74 92 70 80 / 10 20 20 40 50 && .CRP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 94/MJ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 305 PM CDT WED MAY 12 2004 .DISCUSSION...FORECAST FOCUS ON SEVERE WEATHER POTENTIAL INTO THIS EVENING...RAINFALL AND POSSIBLE HEAVY RAINFALL POTENTIAL THROUGH FRIDAY. STRONG SURFACE COLD FRONT...CURRENTLY PRODUCING CONVECTION FROM EASTERN MINNESOTA...PROGGED BY MODELS TO SLOWLY PROPAGATE EAST INTO WESTERN WISCONSIN BY 00Z THURSDAY. AHEAD OF THIS FEATURE...SUBTLE SURFACE CONFLUENT BOUNDARIES WERE COMBINING WITH AN APPROACHING VORTICITY MAXIMUM FROM NORTHEAST MISSOURI...TO PRODUCE SCATTERED THUNDERSTORMS EAST OF THE QUAD CITIES AREA. A FEW SHOWERS WERE FORMING ACROSS THE SOUTHWEST CWA...BUT WERE NOT HOLDING TOGETHER FOR TOO LONG. AS THE VORTICITY MAXIMUM APPROACHES...THE BETTER DEEP- LAYER SYNOPTIC LIFT FROM IT SHOULD BE ABLE TO HELP BETTER SUSTAIN ANY CELLS THAT FORM IN THE CWA INTO EARLY THIS EVENING. THE INSTABILITY IS HERE...WITH 100MB MIXED LAYER CAPES ESTIMATED TO BE 1000-1500 J/KG. RUC SOUNDINGS INDICATE THAT THE ATMOSPHERE IS MIXED OUT AND UNCAPPED...WHICH SHOULD HELP CONVECTIVE CELLS BECOME MORE NUMEROUS BY LATE AFTERNOON. HOWEVER...THE WIND SHEAR IS MARGINAL AT BEST...WITH 0-6 KM SHEAR VALUES OF 20-30KT. DOWNDRAFT CAPES OF 500-1000 J/KG COULD PRODUCE ISOLATED MARGINAL SEVERE WINDS...AND WET BULB ZERO VALUES AROUND 10KFT COULD BRING A MARGINAL SEVERE HAIL HAZARD. HOWEVER...AM NOT OPTIMISTIC THAT THE WEAK SHEAR WILL BE ABLE TO SUPPORT STORMS LONG ENOUGH TO PRODUCE ANYTHING MORE THAN SOME HEAVY RAINFALL. WILL STILL GO WITH CATEGORICAL POPS FOR TONIGHT...AS SURFACE COLD FRONT SLOWLY PROPAGATES INTO CWA...AND STALLS ACROSS THE CWA LATER TONIGHT. HEAVY RAINFALL BECOMES A CONCERN FOR TONIGHT AND AGAIN THURSDAY AFTERNOON THROUGH FRIDAY...AS STALLED SURFACE BOUNDARY COMBINES WITH PARALLEL SOUTHWEST STEERING FLOW ALOFT...AND FAIRLY HIGH PRECIPITABLE WATER VALUES OF AROUND 1.5 INCHES. ALSO...THE GFS MODEL...WHICH HAS HANDLED FEATURES WITH THIS SYSTEM THE BEST OVER THE PAST FEW DAYS...HAS A SURFACE LOW PROPAGATING ALONG THE BOUNDARY THURSDAY NIGHT AND FRIDAY. THIS SHOULD COMBINE WITH GOOD FRONTOGENETIC LIFT FROM A STRENGTHENING 850MB BAROCLINIC ZONE...WHICH WILL BE CROSSING THE CWA ON FRIDAY. LOOKING AT FORECAST SOUNDINGS FROM THE RUC AND GFS...MBE VELOCITIES INDICATE A SLOW BACKWARDS PROPAGATION OF ANY STORMS AND RAIN AREAS TONIGHT...AND AGAIN THURSDAY AFTERNOON THROUGH EARLY FRIDAY...A SIGN OF BACKBUILDING POTENTIAL. ALL IN ALL...WITH FLASH FLOOD GUIDANCE VALUES STILL IN THE 2-3 INCHES PER HOUR RANGE...AND AREA RIVERS STILL ABLE TO TAKE MORE RAINFALL BEFORE ANY WIDESPREAD FLOOD HAZARD DEVELOPS...WILL JUST MENTION HEAVY RAINFALL IN ZONES...AND WILL HOLD OFF ON ANY FLOOD OR HYDROLOGIC ADVISORIES FOR NOW. WILL STILL GO WITH LIKELY POPS THROUGH FRIDAY. SURFACE ANTICYCLONE FINALLY BUILDS INTO THE CWA FRIDAY NIGHT AND SATURDAY...BRINGING AN END TO THE RAIN. COLD AIR ADVECTION BRINGS COOLER TEMPERATURES FOR THE REST OF THE WEEKEND. && .MKX...NONE. $$ WOOD wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 530 AM 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 12Z TAFS...AM RELYING HEAVILY ON GFS SOLN. THIS ALSO LIKE NGM AND ETA HAS POSTPONED FROPA THRU TERMINALS. LONG INVERTED TROF FROM SRN PLAINS RUN BETWEEN ALO AND DBQ THIS MRNG. SLOW PROGRESS ON GFS TAKING FRONT THRU RFD AFTER NOON...CROSSING ORD AFTER MIDNGT TNGT...AND GYY AFTER DAWN FRIDAY. YDA'S TSTMS HAS SATURATED LOWER LAYERS...ALLOWING FOR PLENTY OF LOW CIGS BLO 2K ON BOTH SIDES OF FRONT. MANY CIGS EVEN BLO 1K. THUS WILL NEED TO CONSIDER LOW CIGS AS TEMPO GROUP AT LEAST ALL DAY...THEN TAKING IT DOWN PREVAILING AFTER FROPA. WINDS MUCH LIGHTER THAN YDA...ONLY AROUND 10 KTS IN OPEN GRADIENT OF LOW PRESSURE TROF. SHOWERS APPEAR TO BE LEAVING TERMINALS FOR NOW. HOWEVER A WAVE MOVING UP FRONT THIS AFTN WILL SPAWN IMPETUS FOR FURTHER DEVELOPMENT THIS AFTN AND EVENING. LACK OF STRONG LOW LVL JET MAKES FOR WEAK CHC OF SEVERE...BUT IN TURN INCREASES CHC OF SLOW MOVING...NON-SHEARED HEAVY RAIN PRODUCERS. RESULT CUD BE LOCALIZED FLOODING WHERE SLOW MOVING STORMS TRAIN OVER SAME AREAS. AGAIN WILL NOT PUT TSTMS IN TERMINALS YET. RE-DEVELOPMENT LIKELY THIS AFTN THRU EVENING AS S/W KICKS OUT ACROSS MO INTO IL. THIS WAVE ALLOWING FROPA TO MAKE A CLEAN PASSAGE. BUT OVERRUNNING MOISTURE INTO COOL AIR NORTH OF FRONT HAS ALLOWED CIGS BLO 1K. THESE WILL ADVECT IN BEHIND FROPA OVERNIGHT TO FRIDAY MRNG. RLB && .LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LK MI...NONE. $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 327 AM CDT THU MAY 13 2004 .SYNOPSIS...AN UPPER AIR DISTURBANCE OUT OF SOUTH TEXAS WILL BE MOVING THROUGH THE FORECAST AREA TODAY. SINCE THE ATMOSPHERE AND THE GROUND IS ALREADY SATURATED FROM EXCESSIVE RAINFALL RECENTLY... A FLOOD WATCH HAS BEEN ISSUED FOR TODAY. MORE DISTURBANCES MOVING OUT OF AN UPPER LEVEL TROF OVER THE WESTERN STATES WILL LIKELY GIVE US A REPEAT RAIN EVENT ON FRIDAY. A FRONTAL SYSTEM SAGGING TO THE COAST ON SATURDAY WILL PROVIDE A FOCUS FOR EVEN MORE RAIN AND THUNDERSTORMS. HIGH PRESSURE BUILDING FROM THE EAST WILL END THIS WET AND STORMY PATTERN ON SUNDAY. .DISCUSSION...WENT A BIT LOWER ON TEMPS TODAY FROM THE EXPECTED RAINFALL WHICH SHOULD DRAG DOWN SOME RAIN COOLED AIR. PWS EXCEED 1.5 INCHES WITH K-INDICES OVER 30 AND MEAN RHS EXCEEDING 70%. DEW POINT LINE (ISODROSOTHERM) OF 75F FROM LCH TO CLL THIS MORNING... VERY IMPRESSIVE MOISTURE. ONCOMING NEGATIVELY TILTED SHORTWAVE COMING OUT OF S TEXAS IS A BIT SLOWER ON RUC THAN MESOETA...HOWEVER IR SATELLITE EXTRAPOLATION HAS THIS FEATURE INTO THE FORECAST AREA BY MID-MORNING...NOT FAR OFF MESOETA MOVEMENT. WILL MENTION HEAVY RAINFALL AND CANNOT RULE OUT PULSE SEVERE DUE TO THE NEG TILT TROF. ADDITIONAL SHORTWAVE ENERGY WILL BOOST POPS TO LIKELY AGAIN ON FRIDAY. SATURDAY GOING CATEGORICAL WITH ETA MOVEMENT OF FRONT TO THE COAST WHERE IT WILL LINGER DURING THE DAY. THETA RIDGE AT H7 WILL HELP ENHANCE PRECIP. RIDGE BUILDS IN FROM EAST AT SURFACE NEXT WEEK...AND ALOFT ALONG THE SOUTHERN STATES WHICH SHOULD HELP KEEP PRECIP BELOW CLIMO. THANX FOR THE COORD JAN...LIX...HGX. MARINE...KEEPING WINDS JUST BELOW SCA CATEGORY. && .PRELIMINARY POINT TEMPS/POPS... BPT 79 73 82 66 / 60 30 60 30 LCH 79 71 79 66 / 60 40 70 40 LFT 81 69 81 67 / 70 40 70 40 AEX 78 69 77 63 / 70 40 70 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...FLOOD WATCH...TODAY. TX...FLOOD WATCH...TODAY. && $$ 11 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 550 AM EDT THU MAY 13 2004 .DISCUSSION... MAIN FORECAST CONCERN IS TIMING OF CONVECTION RIDING UP ALONG FRONT TODAY INTO FRIDAY AND THEN PCPN AFFECT ON TEMPS INTO THE WEEKEND. WV LOOP AND RUC ANALYSIS SHOWS WRN TROF/ERN RDG PATTERN OVER NAMERICA. SHRTWV NOTED MOVG UP THROUGH IOWA AND ALONG SFC-850 MB FRONT WHICH STRETCHES FROM THE CENTRAL PLAINS INTO THE UPR MIDWEST. CONVECTION ASSOCIATED WITH THIS SHRTWV CONTINUES TO LIFT NORTHWARD THROUGH IOWA AND SRN MN INTO NCNTRL WI ATTM WHERE RUC SHOWALTER INDICES AOB 0C AND ELEVATED CAPES FROM 200-800 J/KG. TODAY...AM A BIT CONCERNED WITH ANAFRONT CONVECTION MOVG UP FROM SOUTH AS IT IS MOVG NORTHWARD QUICKER THAN WHAT THE 00Z MODELS FORECASTED. WITH 300K ISENTROPIC ASCENT OVER FRONT INCREASING THROUGH THE DAY PER RUC AND GFS AHEAD OF INCOMING SHRTWV...WILL INCLUDE SCATTERED SHOWERS ACROSS THE CWA. WITH SHOWALTER INDICES HOVERING AROUND 0 C ALONG THE FRONT...WILL INCLUDE SOME ISOLATED THUNDERSTORMS AS WELL. WITH SLOW EASTWARD PROGRESSION OF CDFNT ACROSS CWA AND DVPLG NORTH FLOW BEHIND IT...TEMPS WILL NOT REBOUND MUCH FROM MORNING LOWS. HAVE MORNING RANGING HIGHS IN MID TO UPPER 40S WEST TO LOW UPPER 50S AND LOW 60S SOUTH AND EAST WITH TEMPS SLOWLY FALLING THROUGH THE DAY. KEPT IN LIKELY POPS FOR ENTIRE CWA TONIGHT AS MODELS STILL HAVE SFC WAVE LIFTING NORTH WITH GOOD ISENTROPIC LIFT OVER THE FRONT AND INCREASED UPR DIV IN RIGTH ENTRANCE REGION OF STRENGTHENING 120 KT UPR JET OVER WRN ONTARIO. CONSIDERING QUICKER TIMING OF CONVECTION ALREADY TO THE SOUTH...HAVE MOVED UP LIKELY POPS TO EVENING. THUNDER ALSO POSSIBLE...ESPECIALLY EAST AS SHOWALTER INDICES STILL LINGER AROUND 0C PER RUC AND GFS. PREFER COOLER ETA MOS GUIDANCE FOR BOTH THU NIGHT/FRI WITH EXPECTED N WIND AND RAIN. HIGH PRES BUILDS IN FROM THE WEST FRI NIGHT INTO SAT...AS SHOWERS SHOULD END QUICKLY FROM WEST FRI EVENING. 850MB THERMAL TROF OVER THE AREA SHOULD RESULT IN SOME SCT-BKN DAYTIME CU ON SAT OVER INLAND AREAS. ALSO GIVEN FCST OF COOL MIDDAY TEMPS OF 0 TO -1C SW AND -2 TO -3 NORTH AND EAST...HAVE LOWERED HIGHS MORE IN LINE WITH COOLER ETA GUIDANCE WITH MID TO UPPER 40S NORTH AND EAST AND LOW TO MID 50S SOUTH. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 345 AM EDT THU MAY 13 2004 .SHORT TERM... AT 06Z THE SFC WX MAP SHOWS THE COLD FRONT EXTENDS FROM CENTRAL WI SW TO EASTERN IA. THIS FRONT WILL CONTINUE TO SLOW DOWN AND STALL OUT OVER OUR REGION TONIGHT. SEVERAL WAVES OF LOW PRESSURE WILL TRACK NE ALONG THE FRONT. CONVECTION WILL BE ENHANCED BY SEVERAL IMPULSES OF UPPER LEVEL ENERGY MOVING THROUGH OUR AREA. THE 10KM RUC SHOWS THAT ONE SUCH PIECE OF H5 ENERGY IS LOCATED OVER EXTREME SOUTHERN IL/WESTERN KY AT 06Z. IT WILL CONTINUE TO MOVE NE AND CAUSE CONVECTIVE DEVELOPMENT IN PVA NE OF IT ACROSS IL/IN AND EVENTUALLY INTO OUR AREA LATER THIS MORNING AND AFTERNOON. SCATTERED SHOWERS WITH EMBEDDED TSTORMS ARE ALREADY NOTED ACROSS NW AND WESTERN IN... AND MORE ACTIVITY IS NOTED OVER EXTREME SOUTHERN INDIANA IN ASSOCIATION WITH THAT VORT MAX. WE'LL GO WITH LIKELY POPS FOR SHOWERS AND TSTORMS FOR TODAY RIGHT THROUGH FRIDAY AS SEVERAL LOW PRESSURE WAVES TRACK ALONG THE BOUNDARY AND CONVECTION IS ENHANCED BY IMPULSES OF H5 ENERGY. THE SVR WX THREAT THROUGH FRIDAY NIGHT APPEARS FAIRLY MINIMAL, SINCE WIND FIELDS REALLY AREN'T PROGGED TO BE TOO IMPRESSIVE, AND FREEZING LEVELS WILL REMAIN UP THERE AT AROUND 12-13 KFT. A FEW ISOLATED SEVERE STORMS CERTAINLY CANNOT BE RULED OUT, BUT FOR THE MOST PART, THE STORMS WILL JUST PRODUCE FREQUENT LIGHTNING AND HEAVY RAIN. OUR BEST CHANCE FOR SVR WX (THOUGH STILL PRETTY MINIMAL) MIGHT COME LATE FRIDAY JUST AHEAD OF THE COLD FRONT, WHEN FREEZING LEVELS WILL COME DOWN A BIT AND WIND FIELDS WITH HEIGHT WILL INCREASE SOMEWHAT. THIS WILL LIKELY DEPEND ON TIMING AND AMOUNT OF INSTABILITY FROM SFC HEATING FRIDAY AFTN... 00Z ETA GUIDANCE SUGGESTS THE BEST SB CAPES AND INSTABILITY WILL BE WELL SE OF OUR AREA BY FRI AFTN. WE COULD CERTAINLY HAVE SOME HYDRO CONCERNS THROUGH FRIDAY (AND INTO THE WEEKEND B/C OF DELAYED RIVER RESPONSE). THE AIR MASS WILL REMAIN VERY MOIST OVER OUR REGION THRU FRIDAY AND PW VALUES ARE PROGGED TO BE WELL IN EXCESS OF AN INCH AND EVEN APPROACHING TWO INCHES AT TIMES THROUGH FRIDAY AFTN. RAINFALL RATES OF AN INCH AN HOUR WILL CERTAINLY BE POSSIBLE THROUGH FRIDAY WITH STRONGER TSTORMS... ADDING TO ALL THE RAINFALL THAT MANY LOCATIONS HAVE ALREADY RECEIVED IN THE PAST WEEK. AFTER A FEW LINGERING RAIN SHOWERS LATE FRIDAY NIGHT, DRY CONDITIONS WILL FINALLY RETURN SATURDAY, AS A SFC HIGH PRESSURE RIDGE BUILDS IN. .LONG TERM... SFC RIDGING BEGINS MOVING EAST ON SUNDAY WITH RETURN FLOW AND MID LEVEL WARM AIR ADVECTION BRINGING IN CHANCE OF RAIN BY MONDAY AFTERNOON ACROSS THE NORTHWEST FORECAST AREA. THE FRONT PUSHES THROUGH ON TUESDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS ENDING BY 06Z WEDNESDAY. GFS WANTS TO HANG THE FRONT UP JUST TO OUR SOUTH AND MOVE YET ANOTHER SFC LOW TOWARDS LOWER MICHIGAN IN ZONAL FLOW FOR LATE WEDNESDAY INTO THURSDAY...AND THE ECMWF SUGGESTS THIS AS WELL. WILL LEAVE WEDNESDAY DRY FOR NOW...BUT MAY NEED TO ADD PRECIP LATER IF CURRENT MODEL TRENDS HOLD. && .GRR...WATCHES/WARNINGS/ADVISORIES...NONE. && LAURENS OSTUNO mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 336 AM EDT THU MAY 13 2004 .DISCUSSION... 00Z RAOBS/WATER VAPOR LOOP SHOW RIDGE OVER THE EASTERN GREAT LAKES...WITH BROAD LONGWAVE TROUGH OVER THE INTERMOUNTAIN WEST. COMPACT SHORTWAVE/LOW EMBEDDED IN THE TROUGH NEAR LAKE WINNIPEG... WITH 300MB JET FROM THE DAKOTAS TO NORTHWEST ONTARIO. OTHERWISE A SHORTWAVE/SHEAR AXIS WAS LOCATED OVER THE MID MISSISSIPPI/LOWER OHIO VALLEY IN DEEP SOUTHWESTERLY FLOW. SURFACE ANALYSIS SHOWS LOW JUST NORTH OF LAKE SUPERIOR...WITH A COLD FRONT EXTENDING BACK THROUGH WISCONSIN AND BACK TO A WAVE OVER THE SOUTHERN HIGH PLAINS. REGIONAL RADARS SHOW RATHER WIDESPREAD CONVECTION CENTERED AROUND LAKE MICHIGAN IN WARM/MOIST ADVECTION...WITH STORM MOVEMENT GENERALLY TO THE NORTH. MAIN FORECAST FOCUS PRECIP CHANCES ASSOCIATED WITH THE WESTERN TROUGH...AS IT SHIFTS EAST AND SLOW DEAMPLIFIES. SYNOPTICALLY THE 00Z ETA AND GFS ARE IN BETTER AGREEMENT WITH TIMING OF THE UPPER AIR/SURFACE FEATURES...WITH THE ETA TRENDING MUCH SLOWER FROM 00Z/12...CLOSER TO THE CANADIAN/UKMET SOLUTIONS. HOWEVER THERE ARE SMALL-SCALE DIFFERENCES THAT IMPACT THE REGION...MAINLY RELATED TO CONVECTIVE PARAMETERIZATION. GFS STILL HAS A NUMBER OF FEEDBACK ISSUES...WHICH EVEN RESULTS IN A SLOWER AND OVERDEVELOPED SURFACE WAVE. HOWEVER ONCE THE GFS LIFTS THIS DEEPER WAVE THROUGH THE REGION...IT ACCELERATES THE FRONT THROUGH THE REGION FASTER THAN THE ETA. OVERALL WILL KEEP THE FORECAST LEANING TOWARD THE ETA SOLUTION. FOR TODAY...SHORTWAVE NEAR THE LOWER OHIO VALLEY WILL LIFT NORTHEAST ACROSS SOUTHEAST MICHIGAN THIS EVENING. COLD FRONT OVER WISCONSIN WILL MOVE INTO WESTERN LOWER MICHIGAN...BUT THE SLOW DOWN AS ONTARIO LOW DEPARTS AND ANOTHER WAVE DEVELOPS ALONG THE BOUNDARY OVER THE MID MISSISSIPPI VALLEY. DECENT 850MB JET OVER LAKE MICHIGAN LEADING TO WARM/MOIST ADVECTION AHEAD OF THE COLD FRONT. THIS JET SHIFTS EAST ACROSS LOWER MICHIGAN DURING THE DAY...BUT DOES WEAKEN A BIT. HOWEVER THERE IS STILL GOOD MOISTURE FLUX/CONVERGENCE INTO/ACROSS THE CWA TODAY. BOTH ETA AND ESPECIALLY THE GFS WERE TOO MOIST WITH PRECIPITABLE WATER INITIALIZATIONS COMPARED TO 00Z RAOBS...BOTH OVER LOWER MICHIGAN AND UPSTREAM ACROSS ILLINOIS. HOWEVER EVEN WITH MODEL FORECASTS OVERDONE...WE STILL STILL SEE PLENTY OF MOISTURE AVAILABLE...AT LEAST 200 PERCENT OF NORMAL. ONGOING CONVECTION IS NOT MAKING MUCH OF AN EASTWARD PROGRESS. BASED OFF CURRENT RADAR/SATELLITE TRENDS AND RUC/CONVECTIVE INIT FORECASTS...WILL BUMP LIKELY POPS BACK TO THIS AFTERNOON. OTHERWISE SCATTERED/CHANCE WEST/EAST TO START THE MORNING...AS FRONT/UPPER WAVE SLOWLY APPROACH THE CWA. AS FOR SEVERE CHANCES...INSTABILITY WILL BE MODEST TODAY DUE TO LIMITED INSOLATION...HOWEVER ENOUGH TO NOT DOWNPLAY THUNDER CHANCES. 850MB JET REMAINS NEAR 30KTS...BUT 500MB JET QUICKLY DIMINISHES TO LESS THAN 25KTS BY EVENING. SHEAR IS ALSO RATHER WEAK /0-3KM <20KTS/. WITH MORE WIDESPREAD TYPE CONVECTION /NOT NECESSARILY ORGANIZED ALONG A CONVERGENCE ZONE/ DO NOT EXPECT SEVERE WEATHER. DEPENDING ON THE AVAILABLE INSTABILITY SOME STORMS COULD PULSE UP ENOUGH TO PRODUCE HAIL...BUT WITH FREEZING LEVELS NEAR 13KFT IT WILL BE DIFFICULT TO GET ANYTHING MORE. HOWEVER WITH THE SOMEWHAT WEAK WIND FIELD AND A RATHER JUICY AIRMASS...HEAVY RAIN WOULD BE MORE OF A THREAT LEADING TO POTENTIAL HYDRO CONCERNS. UPPER WAVE MOVES THROUGH SOUTHEAST MICHIGAN RIGHT AROUND 00Z. ETA STILL HOLDS ON TO SOME WEAK 850-500MB QVECTOR CONVERGENCE/MOISTURE ADVECTION TO START THE EVENING. EXPECT PRECIP CARRY OVER INTO THE EVENING...BUT WILL ONLY MENTION SCATTERED TSRA RATHER THAN LIKELY WITH SHORT WINDOW FOR TIMING. OTHERWISE WILL HOLD ON TO LOW CHANCE POPS OVERNIGHT WITH SOUTHEAST MICHIGAN BETWEEN WAVES. MAIN SHORTWAVE ENERGY LIFTS INTO THE WESTERN GREAT LAKES ON FRIDAY AND NORTHERN ONTARIO FRIDAY NIGHT...WITH THE WAVY FRONT SLOWLY MAKING ITS WAVE THROUGH LOWER MICHIGAN. CURRENT FORECAST OF LIKELY POPS BOTH FRIDAY/FRIDAY NIGHT LOOKS ON TRACK...AGAIN FAVORING THE ETA SOLUTION. AS THE GFS OVERDEVELOPS A WAVE SOUTH OF THE STATE... IT DELAYS PRECIP UNTIL FRIDAY EVENING. INSTABILITY STILL LOOKS MARGINAL...SO LIKELY SHRA/CHANCE TSRA IS ON TRACK. ALTHOUGH TO TRY AND OFFSET THE DIMINISHED INSTABILITY...THIS SYSTEM WILL BE MORE DYNAMIC. HOWEVER 500MB WINDS DO NOT REALLY INCREASE UNTIL FRIDAY NIGHT BEHIND THE FRONT...AND 850MB JET IS FOCUSED MORE ACROSS OHIO/LAKE ERIE. EVEN WITH FASTER STORM MOVEMENT...WITH PLENTY OF MOISTURE FLUX AND GOOD LIFT TO WRING IT OUT...WE COULD STILL SEE BRIEF HEAVY RAINS. AS FOR WEATHER DIFFERENCES FRIDAY/FRIDAY NIGHT... COULD SEE GOING HIGHER /CATEGORICAL/ FRIDAY NIGHT WITH THE COLD FRONT ITSELF. HOWEVER AT THIS POINT...WITH TIMING ISSUES AND OVERALL UNCERTAINTY AS TO THE IMPACT OF CONVECTIVE SYSTEMS ON TIMING AND MOISTURE FLUX...WILL STICK WITH LIKELY POPS FOR NOW. ETA/GFS BOTH DEPICT THE FRONT THROUGH THE CWA BY 12Z SATURDAY /WITH MINOR DIFFERENCES AS NOTED ABOVE/. THE ETA/GFS TRENDS ARE IN LINE WITH OUR CURRENT GRIDS...HOLDING ON TO A SMALL CHANCE OF RAIN SHOWERS SATURDAY MORNING. OTHERWISE HIGH PRESSURE BUILDS ACROSS THE STATE BY SATURDAY NIGHT. AIRMASS WILL MODERATE SOME BY THE WEEKEND COMPARED TO WHAT IS OBSERVED UPSTREAM ACROSS THE PLAINS...BUT IT STILL LOOKS AWFULLY CHILLY. IN ADDITION TO GOOD COLD ADVECTION... STRONG SUBSIDENCE INVERSION WILL KEEP US FROM MIXING VERY DEEP EVEN WITH SOME BETTER MID-MAY SUN. WILL DROP HIGHS A FEW DEGREES ON SATURDAY...AND ALSO A BIT SATURDAY NIGHT WITH THE HIGH BUILDING OVERHEAD. && .DTX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ BRAVENDER EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 430 AM CDT THU MAY 13 2004 .SHORT TERM...THU THROUGH FRI...FORECAST CONCERNS FOCUS ON ONGOING PCPN CHANCES. WESTERN TROF TO CONTINUE TO SHIFT EAST INTO THE PLAINS DURING THIS PERIOD. CURRENTLY...AT THE SURFACE LOW PRESSURE LIES OVER EASTERN ONTARIO WITH COLD FRONT LYING TO THE SOUTHWEST TO LOW OVER TX PANHANDLE. MORE SPECIFICALLY...COLD FRONT EXTENDS FROM ARV TO MFI AND MAKING SLOW PROGRESS EAST AS LARGE AREA OF CONVECTION LIFTS NORTH THROUGH KS AND IA. THIS AREA OF CONVECTION ALONG 850 FRONT THAT LIES BACK OVER WESTERN WI. QUESTION IS HOW FAR SFC FRONT WILL MAKE IT THROUGH THE AREA TODAY. ETA PUSHES THROUGH BY 15Z...WHEREAS NEW RUC HAS IT INTO GRB AROUND 18Z. WITH UNCERTAINTY OF FRONTAL BOUNDARY AND ONGOING SHOWER ACTIVITY WILL GO WITH SCATTERED WORDING FOR MORNING HOURS. DEVELOPING WAVE ON FRONT TO MOVE INTO AREA THIS AFTERNOON/TONIGHT. MADE LITTLE CHANGE TO PREVIOUS WET FORECAST. WITH CLOUDS AROUND AND GIVEN TEMPS UPSTREAM YESTERDAY... LOWERED TEMPS FOR TODAY SLIGHTLY. HIGH PRESSURE BEGINS TO MOVE IN LATER FRI WITH A DIMINISHING TREND IN THE PCPN. SURFACE BASED INSTABILITY INSIGNIFICANT OVER AREA TODAY...THOUGH 850 MB LIS REMAIN AROUND ZERO THROUGH FRI MORNING. WILL KEEP ISOLATED TSTM WORDING...MAINLY IN SE HALF OF CWA. .LONG TERM...FRIDAY THRU NXT WED. MODELS IN GOOD AGREEMENT WITH SFC WAVE TO MOVE OVER SE WI ALONG SFC FRONT ALSO POSITIONED OVER FAR SE WI. WITH BAROCLINIC ZONE IN PLACE...OCNL R- WITH ISOLD TRW EXPECTED. INSTAB MARGINAL....BUT TT/S ENOUGH TO CONTINUE MENTION. S/W SHOULD FINALLLY MOVE THE FRONT TO THE EAST LATER FRIDAY INTO FRIDAY FOR A DIMINISHING TREND. HIGH PRES BUILDS IN LATER FRIDAY NIGHT TO END THE PCPN AND PSBLY CLR SKIES. WITH COOLER TEMPS AND PSBLY LIGHTER WINDS...PARTS OF NC MAY SEE SCT FROST. MAY MENTION IN THE HWO BUT WILL LEAVE OUT OF THE FCST. HIGH PRES DOMINATES THE REGION EARLY INTO THE WEEKEND WITH COOL DRY CONDITIONS. RETURN FLOW BEGINS LATER INTO THE WEEKEND. INSTAB PSBLY WILL BE SUFFICIENT TO CONT CURRENT SUNDAY AFTN PCPN CHC FOR THE WRN PORTION. WILL CONTINUE WITH THEME OF A FRONTAL BOUNDARY PASSING OVER MONDAY BEFORE DEPARTING MONDAY NIGHT. WILL CONTINUE A DRY FCST TUESDAY AND WEDNESDAY WITH BUILDING HIGH PRES. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MG/AK WWW.CRH.NOAA.GOV/GRB $$ TE/HELMAN WWW.CRH.NOAA.GOV/GRB wi 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. && $$ 11 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1105 AM EDT THU MAY 13 2004 .DISCUSSION... MAIN FCST CONCERNS THIS AFTERNOON ARE PCPN TRENDS AND TSRA CHANCES. WV IMAGERY AND RUC ANALYSIS INDICATED SW MID/UPR LVL FLOW FROM THE SRN PLAINS TO THE WRN LAKES BTWN ROCKIES TROF AND A RDG OVER THE ERN CONUS. A SHRTWV OVER IA AND UPR LVL DIV WITH RIGHT ENTRANCE OF H25 JET FROM THE ERN DAKOTAS INTO WRN ONTARIO SUPPORTED AN AREA OF SHRA/TSRA OVER SE MN AND WRN WI. AT THE SFC...A STATIONARY FRONT EXTENDED FROM ERN UPR MI TO CNTRL WI AND ERN IA. LOW LVL CONV ALONG AND NORTH OF THE FRONT ALONG WITH PLENTIFUL LOW LVL MOISTURE BLO 850 MB...PER 12Z GRB SNDG...HAS BROUGHT AREAS OF -DZ TO CNTRL UPR MI AND NRN WI. EXTRAPOLATION OF RADAR AND SATELLITE TRENDS AND ETA/RUC SUGGEST SHRA/TSRA SHOULD AFFECT MAINLY THE WEST THIRD OF UPR MI THIS AFTERNOON...WITH AREA IN ALSO IN CLOSEST PROXIMITY TO BEST DPVA FROM THE SHRTWV LIFTING NNE. MUCH OF THE EAST SHOULD ESCAPE THE MORE SIGNFICANT PCPN AS SCT ISOLD PCPN WOULD ARRIVE LATE...MAINLY AFT 20Z. WHILE RUC 1000-700 MUCAPE OF 200-400 J/KG REMAINS MAINLY SOUTH OF UPR MI...SOME ISOLD ELEVATED TSRA CANNOT BE RULED OUT GIVEN LIGHTNING TRENDS WITH PCPN SHIELD LIFTING TO THE NORTH. WHILE RADAR HAS SHOWN WEAKENING RETURNS NEAR KMQT...EXPECT SOME -DZ TO CONTINUE WITH LOW LVL MOISTURE IN PLACE AND CONTINUED UPSLOPE FLOW WITH NNE WINDS. OVER N UPR MI...TEMPS HAVE FALLEN FROM EARLY HIGHS AND SHOULD REMAIN IN THE UPPER 40S FOR THE REST OF THE DAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 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 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 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 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 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