####018003052#### AWUS01 KWNH 041840 FFGMPD PAZ000-WVZ000-OHZ000-KYZ000-050000- Mesoscale Precipitation Discussion 0221 NWS Weather Prediction Center College Park MD 240 PM EDT Sat May 04 2024 Areas affected...Southern OH...Western & Northern WV...Ext Southwest PA... Concerning...Heavy rainfall...Flash flooding possible Valid 041840Z - 050000Z SUMMARY...Anomalous moisture and unstable air to produce 1.25-1.75"/hr rates and spots of 2-3" across hilly areas of the Upper Ohio Valley. Scattered Localized incidents of FF possible. DISCUSSION...GOES-E and surface analysis depicted a shallow cyclone from the surface to the remaining weak inflection at 500mb along the IND/OH border. A broad area of anomalous deep layer moisture of 1.25-1.5" exists across much of eastern OH along/head of a surging warm front that lifting from the surface low near Cincinnati across NE KY into far W VA. Clearing skies though the morning and continued modest moisture advection through the mid-levels without stabilizing the mid-levels shows low 70s Ts over upper 60s Tds supporting 1000-1250 J/kg MLCAPEs along the front to the spine of the Appalachians. Currently, the stronger flow/convergence in proximity to increasing orography has resulted in a clustering fo stronger cooling topped thunderstorms across NE KY moving into SW WV. Given moisture and strength of updraft, rainfall generation is supporting 1.5-1.75"/hr. While cell motions of 15-20kts to the northeast are likely to limit duration, increasingly complex terrain and 1-2 hours may result in 2-3" totals which would exceed both the 1 and 3hr FFG values in the area resulting in localized flash flooding. This activity is likely to expand or develop further upstream through the Upper Ohio Valley through the evening with similar concerns of localized 2-3" totals. Further west in SW Ohio... Cell motions are likely to be much slower given proximity to the surface to 700mb low. Initial development may linger for a bit due to said chaotic steering winds, but eastward propagation should begin with eventual outflow development by late afternoon....similar slow moving/SHaRS may dot the 700-500mb confluence axis that extends more or less up I-75 into West-central Ohio. RAP analysis also suggests an 850-700mb boundary extending eastward the may harness the cyclonic convergence along the western side of the WAA in south-central OH and result in downstream development which may allow for multiple rounds of less intense thunderstorms but may still allow for scattered spotty 2-3" totals over a slightly longer duration than elsewhere but result in low-end flash flooding. Gallina ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...PBZ...RLX... ATTN...RFC...OHRFC...NWC... LAT...LON 40778119 40638070 40258036 39718028 39178044 38208093 37518179 38078254 38798332 38958459 39738480 40658385 40338226 ####018001837#### FOUS62 KALR 041841 FFGSJU COUNTY FLASH FLOOD GUIDANCE...PUERTO RICO NATIONAL WEATHER SERVICE SOUTHEAST RIVER FORECAST CENTER...ATLANTA GA 240 PM EDT SAT MAY 4 2024 INCHES OF RAINFALL FOR SPECIFIED DURATIONS REQUIRED TO PRODUCE FLASH FLOODING IN FORECAST ZONES. LOWER AMOUNTS MAY CAUSE FLASH FLOODING IN URBAN OR MOUNTAINOUS AREAS. .B ALR 20240504 Z DH18/DC202405041840 /DUE/PPHCF/PPTCF/PPQCF :IDENTIFIERS ARE 2-LETTER STATE, Z FOR ZONE, 3-DIGIT ZONE NUMBER : :IDENT 1HR 3HR 6HR ZONE NAME :======= ==== ==== ==== ==================== PRZ001 0.8/ 1.4/ 2.0 PRZ002 0.8/ 1.4/ 2.0 PRZ003 0.8/ 1.4/ 2.0 PRZ004 0.8/ 1.4/ 2.0 PRZ005 1.5/ 2.0/ 2.5 PRZ006 1.4/ 1.9/ 2.4 PRZ007 1.4/ 1.9/ 2.4 PRZ008 1.5/ 2.0/ 2.5 PRZ009 1.4/ 1.9/ 2.4 PRZ010 1.5/ 2.0/ 2.5 PRZ011 1.5/ 2.0/ 2.5 PRZ012 1.9/ 3.0/ 4.1 PRZ013 1.9/ 3.0/ 4.1 VIZ001 1.9/ 3.1/ 4.3 VIZ002 1.8/ 2.9/ 4.0 .END $$ S.E.R.F.C. 770-486-0028 or 770-282-2112 Regular Hours 6am-10pm Eastern Time After Hours Please Follow Callback Instructions ####018000979#### PENA01 KWNH 041200 @UHPISF000CNč MPDSUM@V2.0@0101700060@12040524@@0NMCGPHMPD xP@!' `' ` @ ź¾& źBń7)p&¬PNAM02@@3vMüūūūūśūśüś~ū~ūüüżż’€‚ƒƒ„–……ƒƒƒ………~…|‚}ƒ|‚|||€z|{€o’{žz’{ž|ż}@@vM€@@vM€@@ ¹@ūūūūüśūūüü€ƒ…ƒ–†Œ†…ƒ~…}z€zž|ż|ś|ś}ś@@¹@€@@¹@€@@+k żž€€‚‚‚ƒ‚‚„„†…~ƒ~ƒ|{€{{€lž{’{ž{ż{ž{ü|ż|ü|ż}ü~ü~ūü@@k €@@k €@@a€0219 @@‘`€0220 @@`€0221 @@d&€MESOSCALE DISCUSSION SUMMARY GRAPHIC @@d&ž€ OF ALL VALID MESOSCALE DISCUSSIONS AT @@d&ü€ TIME OF PRODUCT CREATION:@@d&ś€ ISSUED 05/04/2024 1840Z @@ d™€NOAA/NWS/NCEP@@d™ž€ WEATHER PREDICTION CENTER @@d™ü€ FOR COLOR VERSION SEE: @@d™ś€ WWW.WPC.NCEP.NOAA.GOV @