914  
FOUS30 KWBC 180035  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
835 PM EDT MON AUG 17 2026  
 
DAY 1  
VALID 01Z TUE AUG 18 2026 - 12Z TUE AUG 18 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF  
THE OHIO VALLEY AND THE CENTRAL APPALACHIANS...  
 
01Z UPDATE...  
THE PREVIOUS OUTLOOK ONLY NEEDED A FEW MINOR ADJUSTMENTS BASED ON  
LATE AFTERNOON/EARLY EVENING RADAR IMAGERY. PREVIOUS DISCUSSION  
REMAINS VALID.  
 
BANN  
 
PREVIOUS DISCUSSION...  
   
..OH/TN VALLEY INTO THE APPALACHIANS
 
 
REGIONAL RADAR MOSAIC THIS MORNING SHOWS CONVECTION ALREADY  
BLOSSOMING ACROSS THE OHIO VALLEY AND INTO PENNSYLVANIA, AS WELL AS  
DRAPED AS FAR SOUTHWEST AS ARKANSAS ALONG THE SLOWLY ADVANCING  
COLD FRONT. WEAK IMPULSES MOVING WITHIN BROAD EASTERN CONUS  
TROUGHING WILL HELP ENHANCE ASCENT THROUGH THIS EVENING, AND THE  
12Z CAMS INDICATE SCATTERED TO WIDESPREAD THUNDERSTORMS WILL  
DEVELOP THROUGH PEAK HEATING. MODEST BULK SHEAR OF 20-25 KTS WITHIN  
A PLUME OF 1.75 TO 2.0 INCH PWS WILL SUPPORT CLUSTERS OF  
THUNDERSTORMS WITH RAINFALL RATES OF 1-2"/HR, BRIEFLY EVEN HEAVIER  
THAN THAT, WITH THE MOST CONCENTRATED HEAVIEST RATES FOCUSED FROM  
THE OHIO VALLEY INTO THE CENTRAL/SOUTHERN APPALACHIANS. THIS AREA  
IS ALSO WHERE THE FFG IS SIGNIFICANTLY COMPROMISED DUE TO RECENT  
HEAVY RAIN, REACHING GENERALLY 0.75-1.5"/3HRS. FORTUNATELY, MEAN  
0-6KM WINDS OF 10-15 KTS WITH SIMILARLY PACED PROPAGATION VECTORS  
ALIGNED PERPENDICULAR TO THE BOUNDARY SHOULD PREVENT SIGNIFICANT  
TRAINING, ALTHOUGH REPEATING ROUNDS OF HEAVY RAIN ARE POSSIBLE IN  
SOME AREAS. THE INHERITED SLGT RISK ENCOMPASSES THE MOST VULNERABLE  
AREAS TODAY, AND WAS TAILORED ONLY COSMETICALLY FROM INHERITED TO  
MATCH THE HIGHEST FFG EXCEEDANCE PROBABILITIES FROM BOTH THE REFS  
AND THE HREF.  
   
..SOUTHWEST
 
 
EXPANSIVE WEST-TO-EAST ORIENTED MID-LEVEL RIDGE DRAPED FROM THE LOW  
DESERTS OF CALIFORNIA THROUGH THE SOUTHERN PLAINS WILL MAINTAIN A  
FAVORABLE PATTERN FOR AT LEAST SOME MONSOONAL CONVECTION TODAY.  
WHILE AIRMASS CONVECTION WILL BE THE PRIMARY MODE, A POTENT  
SHORTWAVE NOTED IN GOES-E WV IMAGERY LIFTING OUT OF WEST TEXAS WILL  
PIVOT W/SW THROUGH THE DAY, PROVIDING AT LEAST LOCALLY ENHANCED  
ASCENT THROUGH SOUTHERN NM AND SOUTHEAST AZ. SUBTLY ENHANCED INFLOW  
WILL HELP DRAW PWS TO AS HIGH AS 1-1.25", LESSER FARTHER NORTH  
INTO THE FOUR CORNERS, TO SUPPORT RAINFALL RATES FOR WHICH THE  
HREF, REFS, AND UA WRF SUGGEST WILL REACH 0.5-1"/HR. WHILE THE CAMS  
ARE NOT EXTREMELY AGGRESSIVE WITH COVERAGE, MEAN 0-6KM WINDS OF  
JUST AROUND 5 KTS INDICATE SLOW MOVEMENT FOR ANY STORMS THAT  
DEVELOP TODAY, POSING A FLASH FLOOD RISK OVER VULNERABLE TERRAIN  
FEATURES OR URBAN AREAS. FOR THIS REASON THE MRGL RISK REMAINS  
SUPPORTED, WITH A SUBTLE EXTENSION SOUTH FROM INHERITED TO CAPTURE  
THE ADVANCING SHORTWAVE.  
   
..CENTRAL PLAINS TO UPPER MIDWEST
 
 
AMPLIFYING MID-LEVEL TROUGH OVER NORTHERN MANITOBA WILL SHED PIECES  
OF ENERGY THROUGH ITS BASE AND INTO THE NORTHERN PLAINS TODAY. ONE  
OF THESE IMPULSES IS PROGGED TO BE POTENT AS IT DROPS NW TO SE FROM  
THE DAKOTAS INTO IOWA THIS EVENING. THIS IMPULSE WILL INTERACT WITH  
A SURFACE FRONT, LEADING TO LOCALLY ACCELERATED AND BACKED INFLOW  
WITHIN A MODEST WARM SECTOR TO THE SOUTH. THIS SHOULD RESULT IN  
INCREASING COVERAGE OF THUNDERSTORMS FROM SOUTH DAKOTA INTO  
NEBRASKA THIS EVENING, WITH ORGANIZATION INTO ONE OR MULTIPLE MCS  
LIKELY OVERNIGHT WITHIN A REGION OF 25-35 KTS OF BULK SHEAR. AS THE  
LLJ BACKS AND AMPLIFIES TO 25-30 KTS, IT WILL DRAW PWS ABOVE 1.5  
INCHES NORTHWARD, OVERLAPPING WITH A PLUME OF 1000+ J/KG MUCAPE TO  
PRODUCE THERMODYNAMICS CAPABLE OF SUPPORTING 1-2"/HR RAINFALL RATES  
(20-40% CHANCE OF 1+"/HR FROM BOTH HREF AND REFS GUIDANCE).  
WHILE STORM MOTIONS MAY BE PROGRESSIVE ON 20 KTS OF 0-6KM WINDS,  
CORFIDI VECTORS ALIGNED TO BOTH THIS MEAN WIND AND THE ELEVATED  
FRONT COULD SUPPORT TRAINING FROM WEST TO EAST, ENHANCING THE  
POTENTIAL FOR EXCESSIVE RAINFALL. THE CAMS CONTINUE TO BE HIGHLY  
VARIABLE IN THEIR FOOTPRINT FOR TONIGHT, BUT THERE APPEARS TO BE A  
FOCUS FROM THE SANDHILLS OF NE INTO WESTERN IA, AS WELL AS A  
SECONDARY MAXIMA ACROSS THE COTEAU DES PRAIRIES OF SD/MN. ANY  
DEVELOPMENT FARTHER SOUTHEAST WOULD IMPINGE INTO LOWER FFG, BUT  
OTHERWISE THE EXCEEDANCE PROBABILITIES WITHIN THE MOST LIKELY  
FOOTPRINT TONIGHT SUGGESTS THE MRGL RISK REMAINS SUPPORTED, AND  
ONLY MINOR COSMETIC ADJUSTMENTS WERE MADE WITH THIS ISSUANCE.  
 
WEISS  
 
 
DAY 2  
VALID 12Z TUE AUG 18 2026 - 12Z WED AUG 19 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF  
THE MIDWEST AND MISSOURI VALLEY...  
 
20Z UPDATE...  
THE PREVIOUS DISCUSSION DOES AN EXCELLENT JOB HIGHLIGHTING THE RISK  
ACROSS THIS REGION ON TUESDAY, AND GUIDANCE HAS UNFORTUNATELY NOT  
COME INTO MUCH BETTER AGREEMENT. THERE WILL BE TWO PERIODS OF  
CONVECTION IMPACTING THIS AREA ON TUESDAY, ONE IN THE MORNING FROM  
A SLOWLY DECAYING OVERNIGHT MCS, AND ANOTHER WITH RENEWED MCS  
DEVELOPMENT LATE IN THE EVENING/OVERNIGHT. THE CAMS ARE SPLIT AS TO  
WHERE THE MORNING IMPULSE WILL TRACK, WITH SOME PUSHING IT EAST  
TOWARDS CHICAGO, AND THE OTHERS BRINGING IT SOUTH ACROSS MISSOURI.  
THE SECOND ROUND AT NIGHT SHOULD BE FARTHER SOUTH, WITH MUCH HIGHER  
PROBABILITIES FOR KS/MO LATER IN THE D2 PERIOD.  
 
THE INHERITED SLGT RISK WAS MAINTAINED, BUT EXPANDED BOTH TO THE  
NORTHEAST AFTER COORDINATION WITH WFO LOT FOR POTENTIAL IN THE  
MORNING, AND TO THE SW TO CAPTURE THE LATEST PROBABILISTIC  
GUIDANCE. ALTHOUGH THIS ENTIRE AREA MAY NOT SEE EXCESSIVE RAINFALL,  
THERE IS ENOUGH SPREAD IN THE HREF AND REFS EXCEEDANCE  
PROBABILITIES TO FEATURE THIS BROADER SLGT RISK ON TUESDAY.  
 
PREVIOUS DISCUSSION:  
LONGWAVE PATTERN ACROSS THE NORTHERN CONUS INTO CANADA WILL LEAD TO  
CONTINUED TROUGH AMPLIFICATION DOWN INTO THE NORTHERN TIER WITH  
MULTIPLE SHORTWAVES MIGRATING UNDER THE TROUGH BASE. TUESDAY WILL  
SEE ONE OF THE MORE PROMINENT WAVES EJECT OUT OF THE NORTHERN  
ROCKIES WITH AN ANTICIPATED DOWNSTREAM AMPLIFICATION AS IT MOTIONS  
INTO THE NORTHERN PLAINS. MID AND UPPER LEVEL HEIGHT FALLS WITH AN  
ATTENDANT VIGOROUS SHORTWAVE WILL TRANSLATE EASTWARD ON TUESDAY  
WITH SIGHTS ON THE EASTERN NORTHERN PLAINS WITH HEAVY CONVECTIVE  
PROSPECTS EXTENDING FROM EASTERN NE DOWN INTO THE MISSOURI VALLEY  
AND ADJACENT CORN BELT (IOWA). A SECONDARY COLD FRONT WILL  
ACCOMPANY THE DISTURBANCE A STRONG SURFACE RIDGE FOLLOWS IN WAKE OF  
THE TROUGH SWINGING THROUGH THE AREA. A COMBINATION OF DIFFLUENT  
FLOW ALOFT AND AMPLE MID-LEVEL VORTICITY ADVECTION INTO A WELL-  
POSITIONED THETA_E RIDGE WILL LEAD TO CONVECTIVE INITIATION ACROSS  
THE SANDHILLS, ONCE AGAIN BUT WITH A GREATER FOCUS DOWNSTREAM GIVEN  
THE VIGOR OF THE SHORTWAVE AND SHARPER COLD FRONT. AMPLE  
INSTABILITY AND PWAT ANOMALIES BETWEEN +1 AND +1.5 STANDARD  
DEVIATIONS ABOVE NORMAL WILL COMPLIMENT THE UPPER FORCING NECESSARY  
TO PROMOTE A PERIOD OF HEAVY THUNDERSTORM ACTIVITY WHERE  
CONVERGENCE IS MAXIMIZED NEAR THE SURFACE AND DIFFLUENT FLOW ALOFT  
WORKS IN TANDEM. ADD IN A MODEST LLJ DEVELOPING ACROSS THE CENTRAL  
PLAINS WITH A NOSE INTO THE MISSOURI RIVER VALLEY AND WE'LL SEE A  
PERIOD OF ENHANCED CONVECTIVE IMPACTS THAT WILL MATERIALIZE TUESDAY  
EVENING, CARRYING THROUGH THE OVERNIGHT PERIOD ACROSS THE  
INTERSECTION OF MO/IA/KS/NE.  
 
ML OUTPUTS HAVE BEEN CONSISTENTLY FAVORING THIS AREA OVER THE PAST  
SEVERAL MODEL ITERATIONS WHICH HISTORICALLY PROVIDES A GREAT ENOUGH  
CONSENSUS TO WARRANT MORE CONFIDENCE IN THE FORECAST. LOCAL TOTALS  
BETWEEN 2-4" ARE FORECAST IN THE MORE HEAVILY IMPACTED AREAS WHEN  
ASSESSING THE LATEST ENSEMBLE PROBS AND DETERMINISTIC FORECASTS  
THAT EXTEND OUT THROUGH THE D2 PERIOD. THE CAMS WINDOW ENDS 00Z  
WEDNESDAY, A BIT BEFORE THE MORE APPRECIABLE IMPACTS OCCUR, SO THE  
NEXT FORECAST UPDATE FOR THE THREAT SHOULD PROVIDE MORE DETAIL ON  
THE THREAT ITSELF, INCLUDING MORE UP TO DATE PROBABILITIES FROM THE  
HI-RES SUITE. IN ANY CASE, THERE WAS ENOUGH CONFIDENCE TO MAINTAIN  
THE PREVIOUS SLGT RISK FORECAST WITH SOME MODIFICATIONS ON THE  
SOUTHWEST FLANK OF THE RISK TO ACCOUNT FOR THE LATEST TRENDS IN  
AVAILABLE GUIDANCE, AS WELL AS MATCHING SOME OF THE CONSENSUS  
WITHIN THE ML FIELDS.  
   
..EASTERN FLORIDA PENINSULA
 
 
BROAD TROUGH EXPANDING ACROSS THE EAST WILL DIG SLIGHTLY INTO THE  
SOUTHEAST TUESDAY, PUSHING A COLD FRONT AND PRE-FRONTAL TROUGH  
TOWARDS THE GULF COAST. THIS PRE-FRONTAL TROUGH IS PROGGED TO PUSH  
DOWN THE FLORIDA PENINSULA IN RESPONSE TO A PUSH OF A MODEST  
SHORTWAVE IMPULSE EMBEDDED WITHIN THE FLOW. AS THIS  
TROUGH/SHORTWAVE DIVE SOUTHWARD, THE OVERLAPPING ASCENT WILL MERGE  
WITH THE PINNED SEA BREEZE INTO ROBUST THERMODYNAMICS CHARACTERIZED  
BY PWS OF 2-2.25 INCHES AND MUCAPE ABOVE 3000 J/KG. THIS WILL  
SUPPORT SCATTERED TO WIDESPREAD THUNDERSTORM DEVELOPMENT, WITH  
RAINFALL RATES ECLIPSING 2"/HR (30-40% CHANCE ACCORDING TO BOTH  
HREF AND REFS). WHILE IN GENERAL THESE STORMS SHOULD MOVE STEADILY  
SOUTHWARD ALONG THE PRE-FRONTAL TROUGH/BENEATH THE SHORTWAVE,  
CORFIDI VECTORS BECOME INCREASINGLY ALIGNED ANTI-PARALLEL TO THE  
MEAN WIND AND COLLAPSE TO AROUND 5 KTS, SUGGESTING STORMS MAY  
BACKBUILD ALONG THE SEA BREEZE LEADING TO A LONGER DURATION OF  
HEAVY RAIN. THIS COULD CREATE 3-5" OF RAIN IN ISOLATED LOCATIONS,  
LEADING TO AN INCREASED RISK FOR FLASH FLOODING, ESPECIALLY ALONG  
THE URBAN I-95 CORRIDOR OF THE EASTERN FLORIDA PENINSULA.  
 
KLEEBAUER/WEISS  
 
 
DAY 3  
VALID 12Z WED AUG 19 2026 - 12Z THU AUG 20 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF  
THE MID-MISSISSIPPI AND OHIO VALLEYS...  
   
..MID-MISSISSIPPI AND OHIO VALLEY
 
 
MID-LEVEL TROUGH WILL GRADUALLY SHARPEN ACROSS THE EASTERN THIRD OF  
THE CONUS ON WEDNESDAY IN RESPONSE TO A SHORTWAVE DIVING FROM THE  
CENTRAL PLAINS INTO THE MID-MISSISSIPPI VALLEY. THIS IMPULSE WILL  
HELP TO AMPLIFY THE LONGWAVE PATTERN IN THE EAST, LEADING TO  
INCREASINGLY IMPRESSIVE FORCING FOR ASCENT THROUGH HEIGHT FALLS AND  
OVERLAPPING RRQ DIFFLUENCE AS AN UPPER JET STREAKS INTO NEW  
ENGLAND. THE AMPLIFYING TROUGH WILL HELP DIG A COLD FRONT SOUTH  
TOWARDS THE TENNESSEE VALLEY BY THE END OF D3, AND THE ACCOMPANYING  
ASCENT ALONG THIS FRONT MAY HELP SPAWN A WAVE OF LOW PRESSURE AS  
WELL TO ENHANCE LIFT.  
 
WHILE THERE IS STILL SPREAD AMONG THE MODELS AS TO HOW WIDESPREAD  
ACTIVITY WILL BE ON WEDNESDAY (BOTH IN SPACE AND TIME DUE TO  
MULTIPLE POSSIBLE MCS/CONVECTIVE CLUSTERS), ANY STORMS WILL BE  
INFLUENCED BY IMPRESSIVE THERMODYNAMICS TO SUPPORT RAINFALL RATES  
OF 1-2"/HR. BULK SHEAR FORECAST TO BE 35-45 KTS WILL HELP ORGANIZE  
THIS CONVECTION, AND WITH BOTH CORFIDI VECTORS AND MEAN 0-6KM WINDS  
ALIGNED TO THE FRONT, EXPECT THERE WILL BE AT LEAST SHORT-TERM  
TRAINING TO LENGTHEN THE DURATION OF THESE INTENSE RATES. WHERE  
THIS OCCURS, 1-3+" OF RAIN IS POSSIBLE, SOME OF THIS FALLING ATOP  
PRIMED SOILS FROM PRIOR RAINFALL. THE ADJUSTED SLGT RISK WAS  
MODIFIED TO MATCH THE GREATEST PROBABILITIES FROM THE GEFS/ECENS,  
WITH SOME EXTENSION IN THE MRGL RISK TO CAPTURE POTENTIALLY LOWER  
RAINFALL, BUT ATOP VERY VULNERABLE SOILS INTO THE OHIO VALLEY FROM  
RECENT HEAVY RAIN.  
   
..SOUTHWEST INTO THE CENTRAL HIGH PLAINS
 
 
UPPER RIDGE CENTERED OVER THE FOUR CORNERS WILL RE-CENTER AND  
AMPLIFY AS AN INVERTED TROUGH PUSHES WEST ON WEDNESDAY. THIS WILL  
PROMOTE A MORE FAVORABLE SETUP FOR MONSOONAL CONVECTION AS A SURGE  
OF THERMODYNAMICS (PWS ABOVE 1.25" OVERLAPPING MUCAPE OF 1000-2000  
J/KG) LIFTING NORTHWARD BEHIND THE INVERTED TROUGH. AT THE SAME  
TIME, WEAK SHORTWAVES EMBEDDED WITHIN THE FLOW AND ROTATING AROUND  
THE RIDGE WILL PRODUCE AREAS OF LOCALLY ENHANCED ASCENT, WHICH INTO  
THE IMPROVING THERMODYNAMICS SUGGESTS MORE WIDESPREAD CONVECTIVE  
ACTIVITY IS LIKELY ON WEDNESDAY. WHILE A MORE SUBSTANTIAL RISK FOR  
GREATER COVERAGE AND INTENSITY EXISTS JUST BEYOND D3, A LARGE MRGL  
RISK FOR EXCESSIVE RAINFALL APPEARS SUPPORTED FROM THE DESERTS OF  
ARIZONA NORTHEAST INTO THE CENTRAL HIGH PLAINS OF CO/KS. WITH  
RAINFALL RATES OF 0.5-1"/HR LIKELY AT TIMES, AND MEAN STORM MOTIONS  
OF JUST 5-10 KTS, (HIGHER IN CO BUT WITH STRONGER BULK SHEAR FOR  
ORGANIZATION) THIS WILL SUPPORT AT LEAST ISOLATED INSTANCES OF  
FLASH FLOODING, ESPECIALLY OVER VULNERABLE TERRAIN, URBAN AREAS, OR  
RECENTLY SATURATED SOILS.  
 
WEISS  
 
 
DAY 4 AND DAY 5  
 
VALID 12Z THU AUG 20 2026 - 12Z SAT AUG 22 2026  
 
...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS  
OF THE SOUTHWEST, OHIO VALLEY, AND MID-ATLANTIC...  
 
2030Z UPDATE...  
EXCEPT FOR A BIT OF A SOUTHWARD EXPANSION IN THE EASTERN US ON  
EACH DAY DUE TO SPAGHETTI PLOTS OF QPF...MAINLY DRIVEN BY EC  
ENSEMBLES...THERE WERE FEW CHANGES NEEDED TO THE PREVIOUS DAY 4/DAY  
5 ERO GRAPHICS.  
 
BANN  
 
PREVIOUS DISCUSSION...  
   
..OHIO VALLEY INTO MID-ATLANTIC
 
 
LARGE SCALE MID TO UPPER LEVEL TROUGHING MOVING INTO THE EASTERN  
U.S. WILL DRIVE AN ACTIVE WEATHER PATTERN ACROSS PORTIONS OF THE  
OH VALLEY AND MID-ATLANTIC THURSDAY INTO FRIDAY. ON THURSDAY (DAY  
4), AN EMBEDDED SHORTWAVE SHOULD TRACK ACROSS THE OH VALLEY INTO  
THE MID-ATLANTIC, INITIATING CONVECTION FROM PORTIONS OF AR AND MO  
NORTHEASTWARD INTO WV. WHILE SOME RECOVERY IS EXPECTED BY THIS  
TIME, RECENT HEAVY RAINFALL HAS LEFT SOILS SATURATED OVER PORTIONS  
OF THIS CORRIDOR, AND THUS HYDROLOGIC SENSITIVITY WILL REMAIN  
HEIGHTENED AND AN ISOLATED FLASH FLOOD THREAT SHOULD EXIST.  
 
FURTHER EAST, A STRONGER MODEL QPF SIGNAL EXISTS ACROSS THE  
EASTERN MID-ATLANTIC, SPANNING FROM VA INTO NJ. IN ADDITION TO A  
SURFACE FRONTAL BOUNDARY ACTING AS A LOW LEVEL FOCUS, UPPER LEVEL  
JET DYNAMICS WITHIN THE FAVORABLE RIGHT ENTRANCE REGION WILL  
ENHANCE LARGE SCALE LIFT. PW VALUES EXCEEDING 2" OVERLAPPING  
STRONG INSTABILITY WILL SUPPORT HEAVY RAINFALL RATES THU INTO THU  
NIGHT. AN EMBEDDED SLIGHT RISK MAY EVENTUALLY BE REQUIRED SOMEWHERE  
FROM EASTERN VA INTO SOUTHEAST NJ...HOWEVER LINGERING UNCERTAINTY  
REGARDING MESOSCALE POSITIONING AND THE CLIMATOLOGICALLY HIGHER FFG  
ACROSS THE COASTAL PLAIN FAVOR KEEPING THE RISK AT MARGINAL FOR  
NOW.  
 
BY FRIDAY (DAY 5), THE MID/UPPER TROUGH WILL DEEPEN OVER THE EAST,  
RESULTING IN A STALLING SURFACE FRONT. WITH ANOMALOUSLY HIGH PWS  
AND MODERATE TO STRONG INSTABILITY REMAINING IN PLACE, THE  
ENVIRONMENTAL SETUP WILL REMAIN CONDUCIVE FOR ADDITIONAL HEAVY  
RAINFALL AND POSSIBLE FLASH FLOODING. MODEL SPREAD INCREASES  
REGARDING THE TIMING AND STRENGTH OF INDIVIDUAL SHORTWAVES  
TRAVERSING THE DEEPENING TROUGH WHICH WILL IMPACT WHERE THE BETTER  
INGREDIENT OVERLAP WILL BE. THE GFS AND ECMWF ARE IN RELATIVELY  
GOOD AGREEMENT BRINGING A HEAVY RAINFALL THREAT FROM THE CAROLINAS  
INTO MD, WHEREAS THE AIFS AND AIGFS SHUNT MORE OF THE DEEPER  
MOISTURE OFFSHORE, KEEPING THE HEAVIEST RAIN EITHER OFFSHORE OR  
ALONG COASTAL AREAS. WHILE A SLIGHT RISK COULD EVENTUALLY BE  
NEEDED, WILL HOLD AT MARGINAL UNTIL MODEL GUIDANCE BETTER CONVERGES  
ON THE EXACT SPATIAL OVERLAP OF FORCING AND MOISTURE.  
   
..SOUTHWEST
 
 
A MARGINAL RISK REMAINS IN PLACE ACROSS PORTIONS OF THE SOUTHWEST  
FOR BOTH THURSDAY AND FRIDAY, WITH THE RISK EXPANDING SLIGHTLY  
NORTHWESTWARD ON FRIDAY RELATIVE TO THURSDAY. A STRONG UPPER LEVEL  
RIDGE WILL REMAIN ANCHORED OVER THE REGION, TRAPPING EMBEDDED  
SHORTWAVE ENERGY WITHIN THE LIGHT FLOW. PLENTIFUL MONSOONAL  
MOISTURE AND INSTABILITY WILL REMAIN IN PLAY, MAKING LOCALIZED  
FLASH FLOODING LIKELY BOTH DAYS. BECAUSE CONVECTIVE FORCING WILL BE  
PRIMARILY TERRAIN INDUCED, OVERALL STORM COVERAGE SHOULD STAY  
BELOW SLIGHT RISK THRESHOLDS. HOWEVER TRENDS WILL CONTINUE TO BE  
MONITORED, AS ANY INCREASE IN CONVECTIVE COVERAGE/ORGANIZATION  
WITHIN THE FAVORABLE CAPE/PW FOOTPRINT COULD SUPPORT A MORE  
CONCENTRATED FLASH FLOOD RISK.  
 
CHENARD  
 
 
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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