926
AWUS01 KWNH 301829
FFGMPD
MNZ000-SDZ000-NDZ000-310030-

Mesoscale Precipitation Discussion 0897
NWS Weather Prediction Center College Park MD
228 PM EDT Thu Jul 30 2026

Areas affected...Parts of northern South Dakota, southeast North
Dakota, and northwest Minnesota

Concerning...Heavy rainfall...Flash flooding possible

Valid 301830Z - 310030Z

Summary...Increasing coverage of slow-moving thunderstorms this
afternoon from north-central South Dakota to northwest Minnesota
are expected to contain rainfall rates up to 2-3"/hr at times.
This may produce isolated to scattered instances of flash flooding
through this evening.

Discussion...GOES-E satellite imagery this afternoon shows cooling
cloud-tops across parts of north-central SD into eastern ND. These
developing thunderstorms are exhibiting slow forward propagation
as wind profiles remain rather light (less than 10 kts) out of the
south up until around 500mb. This southerly flow is also ushering
in a very moist airmass with PWs between 1.8-2.2" and aided by a
tightening mid-level circulation/vort max over western SD. These
values are above the 90th climatological percentile in SD per
30-yr CFSR climo for late-July to early August. Instability is
also not lacking with SBCAPE values over 5000 J/kg along the
border of southeast ND and MN (per SPC`s mesoanalysis). A frontal
boundary gradually sinking across northern ND into northwest MN
will provide an additional focus for thunderstorm development,
which may remain separated from ongoing activity across southeast
ND into northern SD.

Latest HRRR and RRFS highlight maximum rainfall amounts through
01Z around 3-5" are possible. These 3"+ amounts are also supported
by the 12Z HREF and REFS neighborhood probabilities ranging from
20-60% in the region. A limiting factor for widespread flash
flooding is the dry antecedent conditions, with NASA SPoRT-LIS
0-40cm soil moisture below the 5th percentile for much of this
area. However, rainfall rates of 2-3" within this highly moist and
unstable environment could overcome this and produce rapid runoff,
as well as urban flash flooding.

Snell

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...ABR...BIS...DLH...FGF...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON   48979561 48929419 48309392 47409533 46359635
            45309696 44799796 44639919 44850043 45600086
            46670000 48119779