519
AWUS01 KWNH 041911
FFGMPD
MNZ000-SDZ000-NDZ000-050110-
MESOSCALE PRECIPITATION DISCUSSION 0588
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
310 PM EDT FRI JUL 04 2025
AREAS AFFECTED...EASTERN DAKOTAS & NORTHERN MINNESOTA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 041910Z - 050110Z
SUMMARY...BLOSSOMING CLUSTERS OF THUNDERSTORMS TO PRODUCE >2"/HR
RAINFALL RATES POSES A THREAT FOR POTENTIAL FLASH FLOODING THIS
AFTERNOON.
DISCUSSION...A POTENT 500MB TROUGH APPROACHING FROM THE NORTHERN
HIGH PLAINS IS WORKING IN TANDEM WITH THE DIFFLUENT RIGHT-ENTRANCE
REGION OF A STRENGTHENING 250MB JET STREAK OVER THE RED RIVER OF
THE NORTH TO PROVIDE A FAVORABLE SYNOPTIC-SCALE ENVIRONMENT FOR
UPSCALE-GROWTH OF THUNDERSTORMS. A WARM FRONT HAS BEEN LIFTING
NORTH THROUGH NORTHERN MINNESOTA TODAY AND HAS ALREADY TRIGGERED
SEVERAL INTENSE THUNDERSTORMS CLOSE TO THE INTERNATIONAL BORDER.
MEANWHILE, THUNDERSTORMS HAVE FORMED ALONG A SURFACE TROUGH IN THE
HEART OF THE DAKOTAS THAT ARE TRACKING NORTHEASTWARD INTO A MORE
UNSTABLE ENVIRONMENT. DEW POINTS ARE IN THE LOW 70S WITHIN THE
HIGHLIGHTED REGION WITH MLCAPE FORECAST BY THE RAP TO SURPASS
3,000 J/KG AND PWATS ABOVE 2.0". THE PWATS ARE LIKELY TO BE ABOVE
THE 99.5 CLIMATOLOGICAL PERCENTILE PER ECMWF ENS GUIDANCE, AND
WARM CLOUD LAYERS ARE EXCEPTIONALLY DEEP FOR THE REGION. THE ECMWF
ENS GUIDANCE ALSO SHOWS A >750 KG/M/S IVT OVER EASTERN SOUTH
DAKOTA THAT IS AIMED AT NORTHERN MINNESOTA THIS EVENING, FAVORING
THAT AREA FOR THE STRONGEST MOISTURE ADVECTION. BY 00Z THIS
EVENING, RAP SOUNDINGS FOR INTERNATIONAL FALLS, MN SHOW A MELTING
LEVEL NEAR 15,000FT, WHICH IS NEARLY 6,000FT DEEPER THAN THE 90TH
PERCENTILE (~9,000FT) IN THE SPC SOUNDING CLIMATOLOGY. LASTLY,
THESE STORMS WILL HAVE MODEST VERTICAL WIND SHEAR TO KEEP THESE
STORMS ORGANIZED, WITH HIGHER STORM RELATIVE HELICITY VALUES
CLOSER TO THE WARM FRONT OVER NORTHERN MINNESOTA.
THESE FACTORS ALL SUPPORT THE POTENTIAL FOR ORGANIZED CLUSTERS OF
STORMS THAT CAN PRODUCE EXCEPTIONAL RAINFALL RATES THAT GIVE
CREDENCE TO A FLASH FLOOD THREAT THROUGH THIS EVENING. AS THE
STORMS FROM THE DAKOTAS APPROACH INTO THE MORE UNSTABLE AND
SHEARED ENVIRONMENT, STORMS OVER THE DAKOTAS COULD MERGE WITH
DEVELOPING STORMS ALONG THE SURFACE TROUGH. THIS SHOULD EVENTUALLY
SPAWN A LARGER COLD POOL AND BECOME A MORE ORGANIZED MCS THIS
EVENING. RAINFALL TOTALS RANGING BETWEEN 2-4" ARE ANTICIPATED FROM
EASTERN NORTH DAKOTA AND NORTHERN SOUTH DAKOTA ON EAST TO NORTHERN
MINNESOTA THIS AFTERNOON. AREAS LONG THE RED RIVER ON EAST INTO
NORTHERN MINNESOTA HAVE THE BETTER ODDS FOR LOCALIZED AMOUNTS
TOPPING 5" WHERE THEY ARE MORE IDEALLY PLACED CLOSER TO THE WARM
FRONT AND WHERE THE MORE PERSISTENT AREA OF 850MB THETA-E
ADVECTION IS PRESENT. 1-HR FFGS ARE LOWEST ALONG THE RED RIVER AND
ALONG THE MINNESOTA'S INTERNATIONAL BORDER WITH FFGS AS LOW AS
1.5" IN SOME CASES, ALTHOUGH MOST AREAS ALONG THE RED RIVER ARE AS
LOW AS 1.5" FOR 3-HR FFGS AS WELL. GIVEN THESE FACTORS, FLASH
FLOODING IS POSSIBLE IN IMPACTED AREAS. GIVEN IT IS THE FOURTH OF
JULY, THOSE ENJOYING OUTDOOR FESTIVITIES SHOULD BE SURE TO HAVE A
MEANS OF RECEIVING ANY WARNINGS ISSUED THIS AFTERNOON AND EVENING.
MULLINAX
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...ABR...BIS...DLH...FGF...
ATTN...RFC...KRF...MSR...NWC...
LAT...LON 49099548 48989467 48739403 48759326 48469242
47949270 47289413 46499574 45729688 45289728
44869797 44599893 44519977 44650032 44910055
45420052 46000022 47149905 47789833 48209769
48719696 48949645
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