186  
FOUS30 KWBC 032020  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
420 PM EDT TUE JUN 3 2025  
 
DAY 1  
VALID 16Z TUE JUN 03 2025 - 12Z WED JUN 04 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PARTS OF THE  
CENTRAL UNITED STATES, SOUTH FLORIDA AND THE FLORIDA KEYS, AND  
SOUTHWEST...  
   
..16Z UPDATE  
 
THE MAIN CHANGE TO THE PREVIOUS OUTLOOK WAS TO INTRODUCE A SLIGHT  
RISK ACROSS PARTS OF THE SOUTHWEST. MOISTURE LEVELS ARE HIGH FOR  
THIS TIME OF YEAR, WITH THE VEF/LAS VEGAS 12Z SOUNDING SETTING A  
DAILY RECORD FOR PW AT 1.07", WHICH IS CLOSE TO THE 90TH PERCENTILE  
EVEN DURING THE PEAK OF THE MONSOON SEASON/EARLY AUGUST. THE SPC  
MESOANALYSIS SHOWS SOME LOW END BULK SHEAR AROUND 30KT IN NORTHWEST  
ARIZONA, PERHAPS ALLOWING FOR CONVECTION TO BE MORE SUSTAINED AND  
ORGANIZED. INSTABILITY IS ALSO QUITE HIGH FOR THIS TIME OF YEAR,  
WITH THE EXTREME FORECAST INDEX MAXED OUT FOR CAPE OVER THE NEXT  
COUPLE OF DAYS. THESE INGREDIENTS ADDED UP TO INTRODUCING A SLIGHT  
RISK FOR FAR EASTERN CALIFORNIA/FAR SOUTHERN NEVADA AND INTO  
NORTHERN ARIZONA. ALSO, EXPANDED THE MARGINAL RISK WEST A BIT IN  
CALIFORNIA TO AT LEAST COVER THE SAN BERNADINO MOUNTAINS WHERE  
CONVECTION CAN ANCHOR.  
 
ELSEWHERE, THE SLIGHT RISK FOR PARTS OF THE CENTRAL U.S. STILL  
LOOKS IN GOOD SHAPE, WITH A LOCALLY HIGHER END RISK FROM OKLAHOMA  
INTO CENTRAL MISSOURI. EXPANDED THE SOUTHERN END OF THE SLIGHT A  
BIT PER NEWER GUIDANCE. ONLY MINOR CHANGES WERE MADE TO THE RISK  
AREAS IN THE SOUTHERN HALF OF FLORIDA AS WELL.  
 
TATE  
   
..PREVIOUS DISCUSSION  
 
   
..TEXAS TO THE GREAT LAKES  
 
AN ACTIVE DAY OF CONVECTION IS EXPECTED TODAY AS A COLD FRONT SAGS  
ACROSS THE HEARTLAND, PROVIDING THE FOCUS FOR WIDESPREAD SHOWERS  
AND THUNDERSTORMS. THIS FRONT WILL BE PUSHED SOUTHEAST IN RESPONSE  
TO AN AMPLIFYING NORTHERN STREAM TROUGH WHICH WILL DIG ACROSS THE  
CONUS AS FAR SOUTH AS TEXAS. THIS WILL DRIVE HEIGHT FALLS ACROSS  
THE REGION, WITH EMBEDDED SHORTWAVE IMPULSES RACING NORTHEAST, AND  
A POLEWARD ARCING JET STREAK DOWNSTREAM OF THE PRIMARY TROUGH AXIS  
COMBINING TO PROVIDE ADDITIONAL ASCENT. THIS DEEP LAYER LIFT WILL  
WORK INTO ROBUST THERMODYNAMICS CHARACTERIZED BY AN OVERLAP OF  
1.8-2.0" PWS (ABOVE THE 99TH PERCENTILE PER NAEFS) AND A RIBBON OF  
MUCAPE EXCEEDING 2000 J/KG (THROUGH NORTHERN MO), SURGING NORTHWARD  
ON 30-50 KTS OF 850MB FLOW EMERGING ON RETURN FLOW FROM THE GULF.  
 
THE CAMS HAVE CONTINUED TO BE IN EXCELLENT AGREEMENT IN THE COVERAGE  
OF CONVECTION, WHILE ALSO RECENTLY COMING INTO BETTER AGREEMENT ON  
TEMPORAL AND SPATIAL DIFFERENCES (OWING TO TIMING OF THE FRONT).  
CAMS INDICATE WIDESPREAD 1"/HR RAIN RATES FROM THE NORTHERN TX  
HILL COUNTRY ALL THE WAY TO THE EASTERN MISSOURI VALLEY  
(40-KM NEIGHBORHOOD 1"/1-HR PROBABILITIES EXCEEDING 50% ACROSS  
THIS ENTIRE AREA), AND THESE PROBABILITIES INCREASE FROM NORTH TO  
SOUTH OVERTIME TODAY (AS OVERNIGHT CONVECTION LIKELY REMAINS ACTIVE  
IN THE MORNING, THEN GROWS UPSCALE DURING THE DAY). ALTHOUGH MEAN  
0-6KM WINDS OF 20-30 KTS INDICATE PROGRESSIVE STORM MOTIONS, THIS  
FLOW ALIGNED TO THE FRONT AND COMBINED WITH CORFIDI VECTORS THAT  
COLLAPSE AND VEER TO THE NE INDICATE A HIGH POTENTIAL FOR  
REDEVELOPMENT TO THE SW INTO THE MORE INTENSE THERMODYNAMICS AND  
TRAINING OF CELLS TO THE NORTHEAST. WHERE THIS OCCURS, LOCALIZED  
RAINFALL TOTALS EXCEEDING 3" ARE LIKELY (50-80% 3"/24-HR  
NEIGHBORHOOD EXCEEDANCE PROBS ACROSS THE ENTIRE SLIGHT RISK AREA,  
PER 00Z HREF). THE BEST SPATIAL AGREEMENT FOR 2"+ TOTALS (PER 00Z  
HREF EAS 2"/24-HR EXCEEDANCE PROBS) ARE LOCATED WITHIN THE CORE OF  
THE CENTRAL AND NORTHERN PORTIONS OF THE SLIGHT RISK, FROM CENTRAL  
OK THROUGH SOUTHEAST KS AND CENTRAL MO (WHERE 5" NEIGHBORHOOD  
EXCEEDANCE PROBABILITIES ARE ALSO GREATEST, AS HIGH AS 30-50%). THE  
INHERITED SLGT RISK WAS TAILORED TO THIS NEW GUIDANCE, BUT VERY  
LITTLE CHANGE WAS NECESSARY. THE SLIGHT RISK OVER TX IS CONSIDERED  
THE LOWEST CONFIDENCE, AS SPATIAL AGREEMENT (PER HREF EAS PROBS) IS  
LOWEST HERE (THOUGH CONVECTION THAT DOES MANAGE TO DEVELOP ALONG  
THE TAIL OF THIS FRONT WELL INTO THE NIGHT WILL LIKELY FEATURE  
SLOW STORM MOTIONS AND BACKBUILDING, WITH 5" NEIGHBORHOOD  
EXCEEDANCE PROBABILITIES STILL AS HIGH AS 20-30%).  
 
ALTHOUGH HEAVY RAINFALL IS ALSO LIKELY IN CONVECTION THAT DEVELOPS  
NORTHEAST INTO THE UPPER MIDWEST AND GREAT LAKES, STORMS SHOULD BE  
MORE PROGRESSIVE AND THE CORFIDI VECTORS SUGGEST LESS OPPORTUNITY  
FOR TRAINING, SO ONLY A MRGL RISK IS MAINTAINED NORTH OF IA.  
 
   
..SOUTH FLORIDA AND THE FLORIDA KEYS  
 
A SHORTWAVE TROUGH OVER THE GULF HAS AMPLIFIED ENOUGH OVERNIGHT TO  
BECOME A WEAK CLOSED LOW EARLY THIS MORNING, AND IS EXPECTED TO  
SPIN NEARLY IN PLACE AS IT GETS SUPPRESSED BENEATH A BERMUDA- TYPE  
RIDGE TO ITS NORTHEAST. THIS WILL MAINTAIN MODEST SYNOPTIC ASCENT  
ACROSS FLORIDA, BUT SOME ENHANCEMENT IS LIKELY AS A JET STREAK  
OVER THE ATLANTIC TAILS BACK TO THE SW, PLACING THE FAVORABLY  
DIFFLUENT RRQ OVERTOP THE PENINSULA. THIS FORCING WILL COMBINE  
WITH CONTINUED LOW-LEVEL CONVERGENCE ALONG A DECAYED FRONT/SURFACE  
TROUGH, RESULTING IN ANOTHER DAY OF WIDESPREAD SHOWERS AND  
THUNDERSTORMS. PWS IN PLACE WILL AGAIN BE GREATER THAN 2 INCHES,  
ABOVE THE 90TH PERCENTILE ACCORDING TO NAEFS, COMBINING WITH 1000  
J/KG OF CAPE TO PRODUCE ROBUST THERMODYNAMICS TO SUPPORT RAINFALL  
RATES OF 2"/HR AT TIMES. THERE CONTINUES TO BE SOME UNCERTAINTY IN  
THE COVERAGE OF CONVECTION AMONG THE VARIOUS CAMS, BUT BETTER  
AGREEMENT IN THE PLACEMENT OF 3"+ AMOUNT (PER HREF EAS PROBS) ALONG  
THE SOUTHWEST COAST OF FL HAS NECESSITATED AN EXPANSION OF THE SLGT  
TO JUST SOUTH OF TAMPA BAY. WHILE FFG EXCEEDANCE PROBS ARE HIGHEST  
ACROSS THIS AREA, HAVE ALSO MAINTAINED THE SLGT FOR THE REMAINDER  
OF SOUTH FL (INCLUDING ALL OF THE FL KEYS AND THE MIAMI METRO) AS  
LOCALIZED 5" TOTALS REMAIN POSSIBLE (WITH HREF 40-KM NEIGHBORHOOD  
3"/24-HR EXCEEDANCE PROBS OF 30-50% IN VERY CLOSE PROXIMITY).  
 
ALTHOUGH NOT INCLUDED IN A RISK AREA AT THIS TIME, SOME OF THE  
GUIDANCE HAS CONTINUED TO BE A BIT MORE AGGRESSIVE WITH A WAVE OF  
LOW PRESSURE DEVELOPING ALONG AN INVERTED TROUGH ALIGNED TO THE  
EAST COAST OF FLORIDA. IF THIS LOW WERE TO DEVELOP A BIT MORE  
RAPIDLY OR TRACK FARTHER WEST, SOME HEAVY RAIN COULD MOVE ONSHORE  
THE NORTHEAST FLORIDA COAST BEFORE 12Z WEDNESDAY.  
 
   
..FOUR CORNERS  
 
A MRGL RISK WAS FURTHER EXPANDED WESTWARD WITH THIS CYCLE, NOW  
ENCOMPASSING SOUTHEASTERN PORTIONS OF CA THROUGH NV/UT/AZ AND THE  
FOUR CORNERS REGION INTO THE THE CENTRAL PLAINS. THE GUIDANCE HAS  
CONTINUES TO BE MORE AGGRESSIVE WITH SHOWERS AND THUNDERSTORMS  
BLOSSOMING DURING THE AFTERNOON/EVENING AS FORCING INTENSIFIES  
FROM BROAD DIVERGENCE DOWNSTREAM OF A CLOSED LOW FILLING AND MOVING  
INTO THE DESERT SOUTHWEST, PRODUCING ASCENT ATOP A WAVERING  
FRONTAL BOUNDARY POSITIONED OVER THE REGION. THIS LIFT WILL IMPINGE  
INTO FAVORABLE THERMODYNAMICS WITH PWS REACHING ABOVE 0.75 INCHES  
INTO A BUBBLE OF MUCAPE OF 750-1000 J/KG. MEAN STORM MOTIONS WILL  
BE WEAK, GENERALLY AROUND 5 KTS, SO WITH RAINFALL RATES WHICH HAVE  
A 10-40% CHANCE OF EXCEEDING 1"/HR (PER 00Z HREF 40-KM NEIGHBORHOOD  
1"/1-HR EXCEEDANCE PROBS), THESE SLOW MOTIONS COULD RESULT IN  
LOCALLY AS MUCH AS 1" OF RAINFALL IN A SHORT PERIOD OF TIME. IF  
THIS OCCURS OVER SENSITIVE SOILS, URBAN AREAS, OR TERRAIN FEATURES,  
INSTANCES OF FLASH FLOODING COULD RESULT.  
 
CHURCHILL/WEISS  
 
DAY 2  
VALID 12Z WED JUN 04 2025 - 12Z THU JUN 05 2025  
 
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
THE MIDWEST, MIDDLE MISSISSIPPI VALLEY, SOUTHERN PLAINS, THE FOUR  
CORNERS/DESERT SOUTHWEST, AND THE SOUTHEAST...  
   
..2030Z UPDATE  
 
CHANGES TO THE DAY 2 ERO FOR THIS CYCLE WERE RELATIVELY MINOR.  
EXPANDED THE FOUR CORNERS MARGINAL RISK ON THE WESTERN SIDE TO  
ENCOMPASS PARTS OF EASTERN CALIFORNIA AND SOUTHERN NEVADA. HREF  
PROBABILITIES FOR EXCEEDING 3 AND 6 HOUR FFG GUIDANCE ARE SCATTERED  
THROUGH MUCH OF THE SOUTHWEST ONCE AGAIN WEDNESDAY. HOWEVER, THE  
HREF MEAN ETC. SHOWS LOWER INSTABILITY COMPARED TO TODAY (TUESDAY)  
AND SUPPORT ALOFT IS NOT QUITE AS STRONG, SO HELD OFF FROM A SLIGHT  
RISK, BUT EXPECT POSSIBLY ISOLATED TO SCATTERED FLASH FLOODING, BUT  
POSSIBLY LESS FOCUSED. ANOTHER AREA TO WATCH FOR A POTENTIAL  
SLIGHT IS THE SOUTHERN HIGH PLAINS, FOR NOCTURNAL CONVECTION THAT  
MAY PRODUCE HEAVY RAIN RATES BEFORE 12Z THURSDAY, BUT LOOKS TO RAMP  
UP SPECIFICALLY THURSDAY/DAY 3 PERIOD. MEANWHILE, EXPANDED THE  
MARGINAL RISK IN SOUTH-CENTRAL TEXAS FOR SOME WEDNESDAY MORNING  
ONGOING CONVECTION. THE SOUTHEAST TO FLORIDA MARGINAL RISK REMAINS  
SIMILAR TO THE PREVIOUS OUTLOOK.  
 
TATE  
   
..PREVIOUS DISCUSSION  
 
   
..FOUR CORNERS INTO CENTRAL/SOUTHERN HIGH PLAINS  
 
ANOTHER ACTIVE DAY OF SHOWERS AND THUNDERSTORMS EXPECTED AS THE  
UPPER LOW OVER NORTHERN BAJA FILLS AND EJECTS NORTHEAST ATOP THE  
FOUR CORNERS. THE ACCOMPANYING ASCENT WILL MOVE INTO CONTINUED  
ANOMALOUS PWS WHICH WILL EXCEED THE 99TH PERCENTILE (PER NAEFS).  
THIS WILL FUEL WIDESPREAD CONVECTION CAPABLE OF LOCALIZED RAINFALL  
RATES OF 0.5"/HR (OR AT TIMES HIGHER). STORMS WILL LIKELY MOVE  
SLOWLY BENEATH THE UPPER TROUGH, LEADING TO A LONGER DURATION OF  
HEAVY RAIN. ALTHOUGH TOTAL RAINFALL WILL BE MODEST IN MOST AREAS  
(AS REFLECTED BY RELATIVELY LOW 24-HR PROBABILITY FROM ECENS/GEFS  
FOR 1" EXCEEDANCE), WHERE THE HEAVY RAIN IMPACTS SENSITIVE TERRAIN  
FEATURES OR URBAN AREAS INSTANCES OF FLASH FLOODING COULD RESULT.  
PROBABILITIES HAVE ALSO INCREASED A BIT (PARTICULARLY FROM THE NEW  
00Z ECENS SUITE) FURTHER EAST INTO THE CENTRAL/SOUTHERN HIGH  
PLAINS AND THE MRGL RISK HAS BEEN EXPANDED ACCORDINGLY. SHOULD  
MODELS COME INTO BETTER AGREEMENT, ADDITIONAL EXPANSION MAY BE  
NEEDED FURTHER SOUTH INTO WEST TX (AND WITH ADDITIONAL CAM GUIDANCE  
AND AGREEMENT, AN UPGRADE TO SLGT MAY ALSO BE NEEDED).  
   
..SOUTHERN PLAINS AND MID-MISSISSIPPI VALLEY TO GREAT LAKES  
 
THE COLD FRONT FROM D1 WILL CONTINUE ITS TREK EASTWARD ON  
WEDNESDAY, BUT WILL START TO SLOW AND BECOME ALIGNED MORE WEST TO  
EAST AS ITS TAIL GETS PULLED NORTHWARD BY AN APPROACHING SHORTWAVE  
OVER THE FOUR CORNERS REGION. SHORTWAVES EMBEDDED WITHIN THE FLOW  
WILL CONTINUE TO RACE NORTHEAST, ESPECIALLY FROM MISSOURI TO  
MICHIGAN, WHICH IS WHERE THE GREATEST CONCENTRATION OF  
THUNDERSTORMS IS EXPECTED ON D2 (THOUGH SOME MODELS ARE ALSO  
INDICATED POTENTIAL FOR ISOLATED CONVECTIVE DEVELOPMENT FARTHER  
SOUTHWEST INTO PORTIONS OF THE SOUTHERN PLAINS). STORM MOTIONS  
ALONG THE FRONT ARE LIKELY TO BE PROGRESSIVE, LIFTING OFF TO THE  
NORTHEAST ON 0-6KM MEAN WINDS OF 20-30 KTS, BUT WEAKER CORFIDI  
VECTORS ALIGNED BOTH TO THIS MEAN WIND AND THE FRONT SUGGESTS A  
POTENTIAL FOR TRAINING. AS RAINFALL RATES PEAK ABOVE 1"/HR WITHIN  
FAVORABLE THERMODYNAMICS, THIS COULD RESULT IN STRIPES OF HEAVY  
RAINFALL WITH ENSEMBLES INDICATING 10-40% CHANCE OF EXCEEDING 1"  
AND UP TO 10% PROBABILITIES FOR EXCEEDING 2" (WITH THE NEW ECENS  
BEING THE MOST AGGRESSIVE). THE INHERITED MRGL RISK WAS MAINTAINED  
(AND EXPANDED A BIT SOUTHWEST) WITH THIS UPDATE.  
   
..SOUTHEAST  
 
GUIDANCE CONTINUES TO BE SOMEWHAT AGGRESSIVE WITH  
A WAVE OF LOW PRESSURE POTENTIALLY DEVELOPING ALONG AN INVERTED  
TROUGH SHIFTING NORTHEAST ALONG THE FL/GA/SC COASTS. WHILE NHC  
CONTINUES TO INDICATE A 10% PROBABILITY OF TROPICAL OR SUB-TROPICAL  
DEVELOPMENT WITH THIS FEATURE, REGARDLESS OF WHETHER A CIRCULATION  
FORMS OR NOT, THERE CONTINUES TO BE INCREASING CONFIDENCE THAT  
HEAVY RAIN WILL SPREAD ACROSS THE FL PENINSULA AND THEN ROTATE  
ONSHORE THE GA/SC COASTS ON WEDNESDAY. THERE ALSO HAS BEEN A CLEAR  
MODEL TREND OF POTENTIAL INCREASED CONVECTIVE DEVELOPMENT FARTHER  
INLAND TO THE FL PANHANDLE AND INTO SOUTHEAST AL AND SOUTHWEST GA  
(LIKELY DUE TO A STRONGER CLOSED LOW AND THE ASSOCIATED DYNAMICS),  
SO THE MRGL WAS EXPANDED TO REFLECT THIS. WITH PWS PROGGED TO  
EXCEED 2", ABOVE THE 90TH PERCENTILE, SUPPORTED BY WARM CLOUD  
DEPTHS THAT MAY EXCEED 15,000 FT, EFFICIENT RAINFALL RATES OF  
1-2"/HR WILL BE LIKELY IN ANY SHOWERS/THUNDERSTORMS. IT CERTAINLY  
REMAINS POSSIBLE THAT THE HEAVIEST RAINFALL IN ASSOCIATION WITH THE  
POTENTIAL SURFACE LOW WILL REMAIN JUST OFFSHORE, BUT IMPRESSIVE  
MOISTURE CONVERGENCE FROM JACKSONVILLE, FL TO CHARLESTON, SC SHOULD  
SUPPORT WAVES OF HEAVY RAINFALL REGARDLESS OF DEVELOPMENT OF THIS  
SYSTEM. ADDITIONALLY, PLENTIFUL TROPICAL MOISTURE ACROSS THE REST  
OF THE FL PENINSULA AND A SHORTWAVE CONTINUING TO PIVOT ACROSS THE  
GULF COULD ENHANCE RAINFALL OVER MUCH OF FLORIDA WEDNESDAY, AND THE  
MRGL WAS MAINTAINED ACCORDINGLY (WITH THE EXCEPTION OF THE FL  
KEYS, WHICH WERE REMOVED DUE TO MODEL CONSENSUS THAT CONVECTION  
WILL BE PULLING AWAY NORTHWARD BY 12Z WEDS).  
 
CHURCHILL/WEISS  
 
DAY 3  
VALID 12Z THU JUN 05 2025 - 12Z FRI JUN 06 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
THE SOUTH-CENTRAL PLAINS...  
 
...CENTRAL GREAT BASIN TO CENTRAL/SOUTHERN PLAINS INTO THE OHIO VALLEY...  
THURSDAY/DAY 3 SHOULD SEE A SIMILAR PATTERN AS WEDNESDAY/DAY 2,  
WITH A BROAD POSITIVELY TILTED TROUGH AXIS ACROSS THE WEST AND  
SHORTWAVES MOVING THROUGH. PACIFIC MOISTURE (CONTINUING TO BE OVER  
THE 90TH PERCENTILE FOR PWS) WILL STREAM NORTHEASTWARD JUST AHEAD  
OF THE TROUGH TO PRODUCE SCATTERED CONVECTION ACROSS THE CENTRAL  
GREAT BASIN TOWARD THE CENTRAL ROCKIES, SO EXPANDED THE MARGINAL  
RISK INTO THESE AREAS WITH THE AXIS JUST A BIT NORTH OF THE  
PREVIOUS COUPLE OF DAYS.  
 
FARTHER EAST, AN INITIAL SHORTWAVE WILL FORCE CONVECTION IN THE  
SOUTHERN HIGH PLAINS WEDNESDAY NIGHT INTO THURSDAY MORNING. THEN A  
RENEWED LOW LEVEL JET WILL PUSH MOISTURE AND INSTABILITY A BIT  
FARTHER NORTH INTO OKLAHOMA/KANSAS THURSDAY NIGHT AND LIKELY  
SUSTAIN CONVECTION THAT ORIGINATES IN COLORADO, LEADING TO HEAVY  
RAIN RATES. FOR THIS ISSUANCE, COMBINED BOTH THESE AREAS INTO THE  
SLIGHT RISK. THERE CONTINUES TO BE SOME MODEL SPREAD IN HEAVY  
RAINFALL PLACEMENT AND WITH WHICH MCS MAY LEAD TO THE HEAVIER  
TOTALS, WITH MOST RECENT ECENS PROBABILITIES OF EXCEEDING 1" AND 2"  
FOCUSED IN OKLAHOMA WHEREAS GEFS PROBABILITIES ARE CENTERED IN  
KANSAS. SO MORE REFINEMENTS MAY BE NECESSARY IN FUTURE CYCLES.  
EXPANDED THE MARGINAL FARTHER SOUTH IN WEST TEXAS FOR CONVECTION  
WITH HEAVY RAIN RATES JUST EAST OF THE DRYLINE.  
 
TO THE EAST, MOISTURE POOLING ALONG A MEANDERING FRONT MAY LEAD TO  
LOCALLY HEAVY RAIN ACROSS THE MID-MISSISSIPPI VALLEY AND OHIO  
VALLEY TOWARD THE LOWER GREAT LAKES REGION. A MARGINAL RISK REMAINS  
IN PLACE FOR THESE AREAS. CONSIDERED A MARGINAL RISK STRETCHING  
INTO NORTHERN NEW ENGLAND NEAR/AHEAD OF THE FRONT WHERE ABOVE  
NORMAL MOISTURE AND INSTABILITY ARE LIKELY, BUT MODEL QPFS WERE NOT  
VERY HEAVY. THERE IS LIKELY A NONZERO PROBABILITY THOUGH SO WILL  
CONTINUE TO MONITOR.  
   
..SOUTHEAST/CAROLINA COAST  
 
MODEL GUIDANCE INDICATES A LOW PRESSURE SYSTEM POTENTIALLY JUST  
ONSHORE IN THE CAROLINAS NEAR THE ATLANTIC COAST ON THURSDAY. THIS  
SYSTEM IS MOST LIKELY TO BE FRONTAL BUT WITH A LOW END CHANCE OF  
BECOMING TROPICAL OR SUBTROPICAL PER NHC. HEAVIEST RAINFALL TOTALS  
ARE FORECAST TO STAY OFFSHORE. HOWEVER, WRAPAROUND MOISTURE WILL  
STREAM INTO COASTAL AREAS WITH PWS ABOVE THE 90TH IF NOT 95TH  
PERCENTILE. INSTABILITY THOUGH GENERALLY LOOKS TO REMAIN BELOW 1000  
J/KM WEST OF THE LOW, WHICH MAY LIMIT RAIN RATES SOMEWHAT. PER  
COORDINATION WITH THE MOREHEAD CITY (MHX) WFO, ANTECEDENT  
CONDITIONS ARE WETTER THAN NORMAL ALONG COASTAL AREAS DUE TO RECENT  
RAIN. SO WILL CONTINUE TO MONITOR THIS AREA FOR A SLIGHT RISK  
EVENTUALLY, BUT WILL AWAIT BETTER MODEL CONVERGENCE AND SEE IF  
INSTABILITY INCREASES. EXPANDED THE PREEXISTING MARGINAL WEST A BIT  
PER SOME 12Z MODELS THAT WERE FARTHER INLAND.  
 
TATE/CHURCHILL  
 
DAY 1 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/94EPOINTS.TXT  
DAY 2 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/98EPOINTS.TXT  
DAY 3 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/99EPOINTS.TXT  
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