811
AWUS01 KWNH 130511
FFGMPD
MNZ000-IAZ000-NEZ000-SDZ000-131100-
MESOSCALE PRECIPITATION DISCUSSION 1030
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
111 AM EDT THU AUG 13 2026
AREAS AFFECTED...CENTRAL TO SOUTHEAST SD...NORTHEAST NE...WESTERN
IA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 130511Z - 131100Z
SUMMARY...HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE TO ADVANCE
OFF TO THE EAST-SOUTHEAST OVERNIGHT AND MAY TEND TO LOCALLY TRAIN
OVER THE SAME AREA. SOME AREAS OF FLASH FLOODING WILL BE POSSIBLE
GOING THROUGH THE EARLY MORNING HOURS.
DISCUSSION...THE LATEST GOES-E IR SATELLITE IMAGERY SHOWS A STRONG
COLD-TOPPED MCS ADVANCING ACROSS PORTIONS OF WESTERN AND NORTHERN
NE, WITH ADDITIONAL BROKEN CONVECTION NOTED ACROSS CENTRAL AND
SOUTHERN SD. THE ACTIVITY IS ASSOCIATED WITH AN EJECTING SHORTWAVE
TROUGH ACROSS THE NORTHERN PLAINS THAT IS INTERACTING WITH THE
NOSE OF A 30 TO 40+ KTS SOUTHWEST LOW-LEVEL JET AND THE POOLING OF
A MOIST/UNSTABLE AIRMASS POLEWARD OF A STATIONARY FRONT SITUATED
FARTHER SOUTH.
MUCAPE VALUES OF 3000 TO 4000 J/KG ARE STILL IN PLACE WITH PWS AS
HIGH AS 1.75 TO 2.0 INCHES. SUBSTANTIAL SHEAR IS NOTED AS WELL
ACROSS THE NORTH-CENTRAL PLAINS AND ADJACENT AREAS OF THE MIDWEST
WITH EFFECTIVE BULK SHEAR AS HIGH AS 40 TO 50+ KTS. THIS COUPLED
WITH THE CORRIDOR OF STRONG ELEVATED INSTABILITY WILL FAVOR
CONVECTIVE SUSTENANCE THROUGH THE REMAINDER OF THE NIGHT ALONG
WITH CONVECTION CAPABLE OF PRODUCING RAINFALL RATES AS HIGH AS 2
INCHES/HOUR.
THE LATEST 00Z HREF GUIDANCE SUPPORTS RAINFALL AMOUNTS GOING
THROUGH THE PRE-DAWN HOURS AS HIGH AS 3 TO 5 INCHES LOCALLY, WITH
PROBABILITIES OF SEEING THE 3-HOUR FFG EXCEEDED AS HIGH AS 30 TO
50 PERCENT. THIS WILL INCLUDE PRIMARILY AREAS OF CENTRAL TO
SOUTHEAST SD, NORTHEAST NE, AND WESTERN IA.
SOME AREAS OF FLASH FLOODING WILL BE POSSIBLE OVER THE NEXT
SEVERAL HOURS AS A RESULT. THE MORE SENSITIVE URBAN AREAS WILL BE
AT GREATEST RISK FOR SEEING POTENTIAL IMPACTS.
ORRISON
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...ABR...DMX...FSD...GID...LBF...MPX...OAX...UNR...
ATTN...RFC...KRF...MSR...NWC...
LAT...LON 45050013 44599733 43689484 42589384 41589397
41049511 40969628 41149741 42049865 42620006
43640176 44670161
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