467  
FOUS30 KWBC 281952  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
352 PM EDT TUE JUL 28 2026  
 
DAY 1  
VALID 16Z TUE JUL 28 2026 - 12Z WED JUL 29 2026  
 
...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
THE NORTHEAST...  
 
18Z UPDATE: AN UPDATE TO THE DAY 1 ERO HAS BEEN SENT TO EXTEND THE  
MODERATE RISK AREA ACROSS WESTERN MA INTO FAR SOUTHERN VT. MOST  
RECENT GUIDANCE IS POINTING TOWARD A SIGNIFICANT FLASH FLOOD SETUP  
ACROSS THAT AREA BEGINNING THIS EVENING AND CONTINUING THROUGH  
WEDNESDAY MORNING, WHERE TRAINING AND REPEATING ROUNDS OF INTENSE  
RAINFALL IS MOST LIKELY. THE REST OF THE DISCUSSION BELOW REMAINS  
VALID.  
 
TAYLOR  
   
..MID ATLANTIC AND NORTHEAST
 
 
A SIGNIFICANT FLASH FLOODING DAY IS EXPECTED ACROSS PORTIONS OF THE  
MID ATLANTIC AND NORTHEAST. CONVECTION IS RAPIDLY INITIATING  
ALREADY BETWEEN 15-16Z ACROSS MUCH OF THE REGION, AND SHOULD BECOME  
MORE WIDESPREAD BY EARLY-MID AFTERNOON. GROWING INSTABILITY IN  
AREAS OF CLEARING TO THE SOUTHEAST OF ONGOING RAIN, AND INCREASING  
PWS (LIKELY TO APPROACH 2 INCHES IN THE MODERATE RISK AREA BY 21Z)  
SHOULD SUPPORT INCREASINGLY INTENSE RAIN RATES BY THIS AFTERNOON.  
AS CONVECTION BECOMES MORE WIDESPREAD, THERE SHOULD ALSO BE LARGER  
CLUSTERS THAT DEVELOP. THE COMBINATION OF THESE FACTORS SHOULD  
YIELD CORRIDORS WHERE INTENSE RAIN RATES CAN PERSIST IN CERTAIN  
AREAS FOR 2-3 HOURS, AND MAY YIELD LOCALLY EXTREME RAINFALL. ALMOST  
EVERY AVAILABLE HI-RES MODEL SHOWS AT LEAST ONE LOCALIZED MAX OF 5  
OR MORE INCHES OF RAINFALL IN 6 HOURS OR LESS. HOURLY RAIN RATES  
APPEAR LIKELY TO EXCEED 2 INCHES IN THE MOST ORGANIZED CONVECTIVE  
CLUSTERS, AND COULD EVEN REACH 3 INCHES. THEREFORE, THE EXPECTATION  
IS FOR NUMEROUS CASES OF FLASH FLOODING ASSOCIATED WITH THE HIGH  
RAIN RATES FROM THIS AFTERNOON INTO THE EARLY EVENING, WITH THE  
POTENTIAL FOR LOCALLY SIGNIFICANT FLASH FLOODING. GIVEN THE EARLY  
INITIATION OF CONVECTION, THERE IS CONSIDERABLE CONCERN FOR IMPACTS  
DURING THE EVENING COMMUTE IN THE POPULOUS URBAN CENTERS OF THE  
NORTHEAST CORRIDOR.  
 
THERE WILL BE A TRANSITION IN THE CONVECTIVE PATTERN AS WE REACH  
THE OVERNIGHT HOURS. A STRONG MID-LEVEL VORT MAX, VERY EVIDENT IN  
GOES EAST SATELLITE CHANNELS ACROSS NORTH-CENTRAL PENNSYLVANIA, IS  
LIKELY TO INDUCE THE DEVELOPMENT OF A SURFACE LOW SOMEWHERE OVER  
THE REGION. THE POSITION OF THIS SURFACE LOW WILL BE CRITICAL TO  
WHERE THE THREAT OF FLASH FLOODING MAXIMIZES DURING THE OVERNIGHT  
PERIOD AND AS WE APPROACH 12Z (AND THE MORNING COMMUTE). OUR BEST  
ESTIMATE IS THAT THIS WOULD BE FAVORED JUST SOUTHEAST OF THE  
CURRENT TRAJECTORY OF THE SURFACE LOW, AND NEAR THE LARGEST  
CONCENTRATION OF AFTERNOON CONVECTION. FOR NOW THAT LOOKS LIKE IT  
WILL BE SOMEWHERE FROM SE PA TO C NJ BY THE 00-06Z TIME FRAME, AND  
LIFTING NORTHEAST TOWARD S NY AND CT BY 06-12Z. THIS IS WHERE THE  
LATEST 14Z HRRR PLACES IT, AND IS CONSISTENT WITH THE ECMWF  
ENSEMBLE AND AIFS/AIFS ENSEMBLE. HOWEVER, THERE IS STILL  
CONSIDERABLE UNCERTAINTY. THE REASON THE POSITION OF THE LOW IS  
IMPORTANT IS THAT INSTABILITY SHOULD DECREASE WHILE PWS STAY QUITE  
HIGH, FAVORING LOW-TOPPED AND VERY EFFICIENT CONVECTIVE RAIN BANDS,  
AND THESE WOULD TEND TO CONCENTRATE NEAR AND JUST NORTH/EAST OF THE  
SURFACE LOW IN AN AREA OF MAXIMUM MESOSCALE FORCING AND LOW-LEVEL  
CONVERGENCE. THERE ARE ALSO SIGNS THAT RAIN BANDS WILL EXTEND NORTH  
ALONG AN INVERTED TROUGH, PERHAPS WELL UP THE HUDSON VALLEY AND  
INTO VERMONT. WHILE THE MAXIMUM RAIN RATES MAY SLIGHTLY DECREASE  
DURING THE OVERNIGHT PERIOD, MORE INTO THE 1-2 INCH PER HOUR RANGE  
IN THE STRONGEST CONVECTIVE BANDS, THERE WOULD BE GREATER POTENTIAL  
FOR PERSISTENCE, AND THUS LOCALLY EXTREME RAINFALL WILL STILL BE  
POSSIBLE -- THE THREAT WILL JUST SHIFT MORE INTO FAR SOUTHERN AND  
EASTERN NEW YORK, LONG ISLAND, CONNECTICUT, WESTERN MASSACHUSETTS,  
AND SOUTHERN VERMONT. IT'S POSSIBLE THERE WILL BE AN ONGOING RAIN  
BAND WITH ACTIVE FLASH FLOODING AROUND THE END OF THE PERIOD AND IN  
THE TRANSITION TO DAY 2, AROUND THE TIME OF THE WEDNESDAY MORNING  
COMMUTE, PARTICULARLY FROM LONG ISLAND NORTH INTO CONNECTICUT AND  
WESTERN MASSACHUSETTS.  
   
..CENTRAL AND SOUTHERN APPALACHIANS AND VIRGINIA
 
 
A BROADER MARGINAL RISK AREA WAS MAINTAINED FROM SOUTHERN AND  
WESTERN MARYLAND SOUTH INTO VIRGINIA, NORTHERN NORTH CAROLINA, AND  
THE CENTRAL AND SOUTHERN APPALACHIANS. A MORE CONDITIONAL THREAT OF  
LOCALIZED HEAVY RAINFALL AND FLASH FLOODING EXISTS IN THESE AREAS,  
LARGELY DUE TO STRONGER DEEP LAYER MEAN WINDS (OVER 30 KNOTS),  
WHICH SHOULD KEEP STORM MOTIONS RELATIVELY FAST. PRECIPITABLE WATER  
VALUES REMAINING IN THE 1.6 INCH (AT HIGHER ELEVATIONS) TO 2.0 INCH  
(AT LOWER ELEVATIONS) RANGE SHOULD SUPPORT HIGH INSTANTANEOUS RAIN  
RATES, WHICH COULD YIELD LOCALIZED HEAVY RAIN WHERE ANY TRAINING  
COULD OCCUR. HOWEVER, THE OVERALL PATTERN DOES NOT FAVOR WIDESPREAD  
TRAINING, AND THUS THE THREAT IS MORE CONDITIONAL.  
   
..FOUR CORNERS STATES
 
 
THE PRIMARY ADJUSTMENT WAS TO EXPAND THE SLIGHT RISK TO INCLUDE  
MUCH OF NORTHERN ARIZONA, WHERE PROBABILITIES OF LOCALIZED HEAVY  
RAINFALL HAVE INCREASED. THE MARGINAL RISK WAS ALSO PUSHED WEST IN  
UTAH TO ACCOUNT FOR SOME SIGNAL FOR SLOW-MOVING THUNDERSTORMS.  
OVERALL, THE PREVIOUS REASONING STILL APPLIES. THE STRONGEST SIGNAL  
FOR HEAVY RAIN IS IN NORTHEAST COLORADO WHERE PRECIPITABLE WATER  
VALUES ARE ABOVE THE 90TH PERCENTILE AND DEEP LAYER MEAN WIND AND  
CORFIDI VECTOR MAGNITUDES ARE LOWER (GENERALLY 10 KNOTS OR LESS).  
THEREFORE, THE GREATEST CONCERN WOULD BE AROUND THE TIME OF  
CONVECTIVE INITIATION OVER HIGHER TERRAIN, AND FOR THE SEVERAL  
HOURS AFTERWARD. WITH BULK SHEAR OF 30-40 KNOTS, HOWEVER, AS THE  
STORMS BECOME MORE NUMEROUS THEY SHOULD BEGIN TO ORGANIZE INTO  
CLUSTERS OR LINES AND BEGIN TO ESTABLISH COLD POOLS AND ACCELERATE  
EASTWARD ONTO THE PLAINS, WHICH WOULD EVENTUALLY REDUCE THE THREAT  
OF FLASH FLOODING. FURTHER TO THE SOUTHWEST (NM, AZ), STORM MOTIONS  
SHOULD REMAIN RELATIVELY SLOW AND SHOULD PROMOTE THE THREAT OF  
ISOLATED FLASH FLOODING.  
   
..WESTERN FLORIDA PENINSULA AND THE KEYS
 
 
NO CHANGES. PREVIOUS DISCUSSION: A SHORTWAVE DIVING ALONG THE  
FLORIDA PENINSULA/WESTERN GULF WILL INTERACT WITH BROAD DIFFLUENCE  
ALOFT TO MAINTAIN DEEP LAYER ASCENT FOR CONVECTION ACROSS THE  
EASTERN GULF AND INTO PARTS OF SOUTH FLORIDA AND THE KEYS. MEAN  
0-6KM WINDS OF JUST 5-10 KTS WILL BE ALIGNED SW TO NW, ANTI-  
PARALLEL TO COLLAPSED CORFIDI VECTORS, AND PARALLEL TO THE KEYS.  
THIS SUGGESTS THAT CONVECTION WILL REPEATEDLY BUILD ACROSS THE GULF  
WHERE PWS WILL BE POOLED AT 2-2.25 INCHES WITHIN IMPRESSIVE  
2000-3000 J/KG MUCAPE LEADING TO 2-4" OF RAINFALL WITH LOCALLY  
HIGHER AMOUNTS.  
   
..MISSOURI VALLEY
 
 
A MARGINAL RISK WAS MAINTAINED BUT THE SLIGHT RISK WAS REMOVED  
ACROSS THIS REGION, GIVEN A REDUCED SIGNAL IN THE HI-RES ENSEMBLE  
GUIDANCE FOR HEAVY RAINFALL.  
 
LAMERS/BANN  
 
 
DAY 2  
VALID 12Z WED JUL 29 2026 - 12Z THU JUL 30 2026  
 
...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
THE NORTHEAST...  
   
..NORTHEAST
 
 
INTENSE RAINFALL, SOME OF WHICH WILL BE TRAINING AND REPEATING, IS  
EXPECTED TO BE ONGOING AT THE START OF THE DAY 2 PERIOD WEDNESDAY  
MORNING, PARTICULARLY ACROSS WESTERN MA, FAR SOUTHERN VT, AND  
BROADLY ACROSS SOUTHERN NEW ENGLAND. RAINFALL RATES BETWEEN 1-2"/HR  
AT TIMES WILL BE POSSIBLE THROUGH LATE MORNING/EARLY AFTERNOON AND  
TOTALS OF 2-4" (WITH LOCALIZED HIGHER AMOUNTS POSSIBLE) ARE  
EXPECTED. HREF NEIGHBORHOOD PROBABILITIES REMAIN HIGH (GREATER  
THAN 80 PERCENT) FOR 3" TOTALS ACROSS WESTERN/CENTRAL MA INTO FAR  
SOUTHERN VT. PROBABILITIES ARE MODERATE (30-50 PERCENT) FOR 5"  
TOTALS.  
 
GIVEN THE SETUP AND RISK OF SIGNIFICANT FLASH FLOODING CONTINUING  
FROM THE DAY 1 PERIOD, A MODERATE RISK HAS BEEN INTRODUCED FOR THE  
DAY 2 PERIOD, MAINLY TO ACCOUNT FOR WHAT IS EXPECTED TO BE ONGOING  
IN THE EARLY PART OF THE PERIOD. THE SECOND HALF OF THE PERIOD  
(AFTER 00Z THU), THE INTENSITY OF RAINFALL SHOULD SUBSIDE WHILE  
ALSO SHIFTING EASTWARD.  
   
..FOUR CORNERS STATES INTO THE CENTRAL/NORTHERN PLAINS
 
 
MONSOONAL FLOW PERSISTS WITH ISOLATED TO WIDELY SCATTERED  
CONVECTION EXTENDING FROM THE FOUR CORNERS REGION NORTH AND  
EASTWARD...PERHAPS EXTENDING AS FAR EAST AS THE PLAINS OF COLORADO.  
SOME OF THIS RAIN COULD FALL ATOP SOILS SATURATED FROM HEAVY RAIN  
ON TUESDAY AND TUESDAY NIGHT. OVERALL, THE RISK AREA REMAINS IN  
GOOD SHAPE WITH THE SLIGHT RISK FOCUSED ON EASTERN COLORADO.  
   
..CENTRAL GULF COAST REGION INTO PARTS OF THE SOUTHEAST
 
 
A COLD FRONT STALLING ALONG THE GULF COAST WILL BE A FOCUS FOR SLOW  
MOVING AND TRAINING THUNDERSTORMS ON WEDNESDAY. GUIDANCE CONTINUES  
TO INDICATE A LOW-PROBABILITY THREAT FOR AT LEAST 3" OF RAIN DUE TO  
TRAINING OF 1-2"/HR RAIN RATES WITHIN FAVORABLE THERMODYNAMICS.  
THIS REGION CAN GENERALLY TOLERATE SIGNIFICANT RAIN RATES AND THIS  
AMOUNT OF RAINFALL, BUT ANY MORE PRONOUNCED TRAINING COULD RESULT  
IN ISOLATED FLASH FLOOD RELATED IMPACTS.  
 
TAYLOR/BANN/WEISS  
 
 
DAY 3  
VALID 12Z THU JUL 30 2026 - 12Z FRI JUL 31 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF  
THE LOWER MISSOURI AND MID TO UPPER MISSISSIPPI VALLEY...  
   
..LOWER MISSOURI VALLEY INTO THE MID-UPPER MISSISSIPPI VALLEY
 
 
SHORTWAVE ENERGY WILL BE PROGRESSING EAST SOUTHEAST AS IT TRACKS  
ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS ON THURSDAY INTO  
THURSDAY NIGHT/EARLY FRIDAY MORNING. THE SHORTWAVE ENERGY WILL BE  
ENCOUNTERING AN INCREASINGLY MOIST AND UNSTABLE AIRMASS WITH  
PRECIPITABLE WATER VALUES IN EXCESS OF 2 INCHES BEING DRAWN INTO  
THE REGION AHEAD OF THE SHORTWAVE. GIVEN THE MCS/UPSCALE GROWTH  
POTENTIAL WITH THIS SYSTEM, CONCENTRATED AREAS OF HEAVY RAIN ARE  
EXPECTED, ESPECIALLY ACROSS THE CORN BELT. THE SLIGHT RISK IS IN  
GOOD SHAPE AND COVERS THE ENSEMBLE GUIDANCE AND UNCERTAINTY/SPREAD  
AMONG THE MODELS.  
   
..FOUR CORNERS STATES INTO THE CENTRAL/NORTHERN PLAINS
 
 
MONSOONAL FLOW AND ANOMALOUS DEEP-LAYER MOISTURE WILL MAINTAIN AN  
ISOLATED EXCESSIVE RAINFALL RISK EXTENDING FROM EASTERN ARIZONA  
NORTHEASTWARD ACROSS MUCH OF WESTERN AND NORTHERN NEW MEXICO INTO  
PARTS OF COLORADO. THE EXPANDING MID/UPPER LEVEL RIDGE WILL LIKELY  
LIMIT THE COVERAGE COMPARED TO RECENT DAYS.  
   
..CENTRAL GULF COAST REGION INTO PARTS OF THE SOUTHEAST
 
 
HEAVY RAINFALL IS EXPECTED ALONG A FRONT ASSOCIATED WITH A LOW  
PRESSURE SYSTEM WHICH WILL BE PULLING AWAY FROM NEW ENGLAND.  
HEAVY RAINFALL WITH SOME POTENTIAL OF FLOODING WILL BE FOCUSED  
ALONG AND NEAR THE FRONT...ESPECIALLY OVER PARTS OF FLORIDA AND  
GEORGIA LINE.  
   
..NEW ENGLAND
 
 
THE DEPARTING LOW PRESSURE IS EXPECTED TO BE ACROSS EASTERN MA AT  
THE START OF THE PERIOD AND TRANSITION OFF THE COAST DURING THE  
PERIOD. LOCALLY HEAVY RAINFALL WILL REMAIN POSSIBLE ACROSS THE  
REGION GIVEN ITS PROXIMITY AND AMPLE MOISTURE TO WORK WITH. WHILE  
THE INSTABILITY WILL LIKELY BE LESS COMPARED TO TUESDAY/WEDNESDAY,  
THE STRONGER DYNAMICS AT PLAY AND POTENTIAL FOR TRAINING RAINFALL  
COULD LEAD TO A LOCALIZED THREAT, PARTICULARLY IF OVER AREAS MORE  
SATURATED FROM PREVIOUS RAINFALL. A MARGINAL RISK WAS ADDED.  
 
TAYLOR/BANN  
 
 
DAY 4 AND DAY 5  
 
VALID 12Z FRI JUL 31 2026 - 12Z SUN AUG 02 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FRIDAY ACROSS  
PARTS OF THE MID AND UPPER MISSISSIPPI, AND ON SATURDAY OVER  
PORTIONS OF THE LOWER OHIO VALLEY, TENNESSEE VALLEY, AND DEEP  
SOUTH...  
 
20Z UPDATE: PREVIOUS FORECAST AND SYNOPSIS ON THE UPCOMING PATTERN  
REMAINS PREVALENT AND CONSISTENT WITH REGARDS TO RUN-TO-RUN  
CONTINUITY. BIGGEST ADJUSTMENT FOR THE D4 WAS A MINOR EXPANSION TO  
THE EAST OVER SOUTHERN WI AND NORTHERN IL FOR THE SLGT RISK AS  
ENSEMBLE MEAN QPF >1" SAW A SMALL SHIFT IN THAT DIRECTION IN THE  
12Z NWP SUITE. THIS CORRELATES FAVORABLY WITH THE EC-AIFS QPF  
ALIGNMENT WHICH IS EVEN FURTHER EAST THAN WHAT IS CURRENTLY  
FORECAST AS THE HEAVIEST QPF IS EVEN EAST OF THE MISSISSIPPI AROUND  
IA/IL. DIDN'T WANT TO ENGAGE IN THAT LARGE OF A SHIFT, SO SPLIT THE  
MIDDLE AND CORRELATED THE SLGT RISK WITH THE PQPF >1" PROBABILITY  
THAT WAS GREATER THAN 30%, A THRESHOLD THAT TYPICALLY FAVORS MORE  
OF A SLGT RISK OPPORTUNITY FOR THE D4 PERIOD.  
 
THE D5 SAW AN ADJUSTMENT OF THE SLGT RISK FURTHER TO THE N/NW OVER  
IL/IN AS THE UPPER LEVEL PROGRESSION FROM OUR SHORTWAVE OVER THE  
UPPER MIDWEST WILL PLAY A SIGNIFICANT ROLE IN WHERE THERE WILL BE  
NOT ONLY SUFFICIENT CONVECTIVE COVERAGE, BUT ALSO FOCUSING AN AREA  
WHERE TRAINING/REPEATING CELL DEVELOPMENT COULD PLAY A GREATER ROLE  
FOR FLASH FLOOD PROSPECTS. THERE'S A GENERAL CONSENSUS ON THE  
PRIMARY CIRCULATION ALOFT CUTTING THROUGH IL AND POTENTIALLY  
CLOSING OFF SOMEWHERE OVER EASTERN IL DOWN TOWARDS THE WESTERN OHIO  
VALLEY. SOME OF THE DETERMINISTIC IS PRETTY AGGRESSIVE IN THEIR QPF  
PRESENTATIONS, MAINLY THE MODELS THAT SHOW THAT EARLIER CLOSED 5H  
SIGNAL. IN THIS CASE, ENOUGH MERIT WITH THE ENSEMBLE QPF INCREASE  
IN THE REGION TO TO MOVE THE SLGT A BIT FURTHER N/NW TO ACCOUNT FOR  
THE TREND.  
 
THERE WERE NO SIGNIFICANT CHANGES TO THE MRGL RISK OUTLINES ACROSS  
THE SOUTHEASTERN U.S. AND THE SOUTHWESTERN U.S. WITH THEIR  
RESPECTIVE PATTERNS AS THE QPF FORECAST REMAINS PRETTY CONSISTENT  
ACROSS THE CENTRAL GULF COAST INTO FL.  
 
KLEEBAUER  
 
..PREVIOUS DISCUSSIONS..  
   
..MISSISSIPPI VALLEY-OHIO VALLEY-TENNESSEE VALLEY-DEEP SOUTH
 
 
ON DAY 4 (FRIDAY-FRIDAY NIGHT), MINOR CHANGES WERE MADE TO  
YESTERDAY'S DAY 5 ERO, INCLUDING REFINEMENTS TO THE SLIGHT RISK  
AREA OVER PARTS OF THE MID-UPPER MS VALLEY, BASED ON THE LATEST  
(00Z) GLOBAL DETERMINISTIC AND PROBABILISTIC QPFS. THE OPERATIONAL  
MODELS CONTINUE TO SHOW MAX 24HR TOTALS IN THE 3-5" RANGE,  
PARTICULARLY OVER IA-SOUTHEAST MN-SOUTHWEST WI, THOUGH AGAIN WITH  
SOME SPATIAL SPREAD IN THE GUIDANCE. 00Z OPERATIONAL ECMWF HAS A  
BIT MORE AREAL COVERAGE OF THE 3+ INCH TOTALS, WHILE THE ECENS QPF  
EXCEEDANCE PROBABILITIES HAVE ONCE AGAIN COME UP FROM THE PREVIOUS  
RUN. BASED ON THE LATEST GUIDANCE, ALONG WITH THE MOST RECENT ECMWF  
EFI OUTPUT (EFI VALUES AOA 0.6), HAVE NUDGED THE SOUTHERN PORTION  
OF THE SLIGHT RISK AREA A LITTLE FARTHER NORTH ACROSS THE MID MS  
VALLEY.  
 
ON DAY 5 (SATURDAY-SATURDAY NIGHT), THE GLOBALS CONTINUE TO SHOW A  
FAIRLY VIGOROUS 500 MB TROUGH/EMBEDDED SHORTWAVE ENERGY SLOWLY PIVOTING  
INTO THE MID MS VALLEY. THERE ISN'T AS STRONG OF A SIGNAL IN THE  
QPF GUIDANCE COMPARED TO THE PREVIOUS COUPLE OF DAYS; HOWEVER, THE  
AMPLIFYING UPPER LEVEL TROUGH (FAVORABLE QS FORCING AND INCREASING  
EFFECTIVE BULK SHEAR) WILL COMBINE WITH A FAVORABLE THERMODYNAMIC  
PROFILE (ML CAPES 1000-2000 J/KG ALONG A SWATH OF 1.8-2.1" PWS) TO  
GENERATE ORGANIZED HEAVY RAINFALL THREAT ACROSS WESTERN PORTIONS  
OF THE LOWER OH VALLEY INTO THE TN VALLEY AND PERHAPS AS FAR SOUTH  
AS SOUTHERN AL, DEPENDING ON HOW FAR SOUTH THE UPPER SHORTWAVE AND  
FAVORABLE 0-6KM BULK SHEAR CAN GET. CONCERN WITHIN THIS AREA WILL  
BE HEAVY RAINFALL RATES (2+ IN/HR) GIVEN THE THERMODYNAMIC PROFILE,  
ALONG WITH THE POTENTIAL FOR CELL TRAINING OF CONVECTION AS THE  
UPPER SHORTWAVE BEGINS TO STALL AND THE LOW-LEVEL INFLOW OUT AHEAD  
OF IT INCREASES UP AND ALIGNS MORE PARALLEL TO THE MEAN 850-300 MB  
FLOW. BECAUSE OF THESE FACTORS, WE FELT THAT A SLIGHT RISK WAS  
WARRANTED.  
   
..FOUR CORNERS STATES INTO THE SOUTHERN-CENTRAL HIGH PLAINS
 
 
MONSOONAL FLOW AND ANOMALOUS DEEP-LAYER MOISTURE WILL MAINTAIN A  
MARGINAL (ISOLATED) EXCESSIVE RAINFALL RISK OVER EASTERN AZ AND  
MUCH OF NM INTO MUCH OF CO. THE EXPANDING MID/UPPER LEVEL RIDGE  
(600DM HEIGHTS AT 500 MB) WILL LIKELY LIMIT THE COVERAGE COMPARED  
TO RECENT DAYS, ESPECIALLY ON FRIDAY.  
   
..CENTRAL GULF COAST REGION INTO PARTS OF THE SOUTHEAST
 
 
HEAVY RAINFALL IS EXPECTED ALONG THE NEW ENGLAND CYCLONE'S TRAILING  
FRONT NEAR THE FL/GA BORDER, THE FRONT THAT WILL BECOME MORE  
QUASI-STATIONARY THU-FRI BEFORE LIFTING LIFTING BACK NORTH ON SAT  
AHEAD OF THE APPROACHING UPPER TROUGH. DEEP-LAYER MOISTURE AND  
INSTABILITY SHOULD BE MORE THAN SUFFICIENT AND THE GUIDANCE SHOWS  
SUFFICIENT EFFECTIVE BULK SHEAR (0-6KM MAGNITUDES GENERALLY OVER 20  
KTS) FOR MORE ORGANIZED/PERSISTENT CONVECTIVE ORGANIZATION. AS A  
RESULT, HAVE MAINTAINED THE INHERITED MARGINAL RISK ON DAY 4 (FRI-  
FRI NIGHT), WITH A SIMILAR MARGINAL RISK AREA ON DAY 5 (SAT-SAT  
NIGHT).  
 
HURLEY  
 
 
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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