AWUS01 KWNH 031455
FFGMPD
NEZ000-SDZ000-032053-

Mesoscale Precipitation Discussion 0575
NWS Weather Prediction Center College Park MD
1053 AM EDT Fri Jul 03 2026

Areas affected...western/central South Dakota

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

Valid 031453Z - 032053Z

Summary...Convection persists across the discussion area, with
locally heavy rainfall noted along and just north of an expansive
outflow boundary across the region. Flash flooding remains
possible on an isolated basis.

Discussion...Scattered convection has persisted across the
discussion area along and north of an outflow boundary
subjectively analyzed to extend from near the MT/WY/SD border
southeastward through Rapid City and eastward toward the SD/NE
border near Valentine. Convection is currently outperforming much
of the model guidance in this region, and remains tied to several
factors, including 1) a broad cold pool that continues to be
reinforced by deep convection/rainfall across the discussion area,
2) weak mid/upper waves from the northern Rockies (including one
centered over southeastern MT) providing ascent aloft to support
updrafts, and 3) very unstable air aloft (8-8.5C mid-level lapse
rates) that continue to move over the region via advection processes.

While the persistence of convection across the discussion area is
a bit uncertain, ongoing trends (including towering cumulus and
lightning in southeastern MT) suggest that at least isolated
convection will extend potentially into the early afternoon hours
even amid weakening low-level flow in areas along the periphery of
the cold pool. Furthermore, with locally heavy rainfall occurring
over areas of low FFG (between 0-1 inch/hr in many areas), it
appears that flash flooding will remain a possibility through the
afternoon on an isolated basis as well.

Cook

ATTN...WFO...ABR...FSD...LBF...UNR...

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

LAT...LON 45630255 44970029 44089936 43209949 42890048=20
43210263 43920378 45520392=20

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