355
AWUS01 KWNH 240820
FFGMPD
NDZ000-241218-

Mesoscale Precipitation Discussion 1119
NWS Weather Prediction Center College Park MD
419 AM EDT Mon Aug 24 2026

Areas affected...portions of northern/northeastern North Dakota

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

Valid 240818Z - 241218Z

Summary...Spotty/isolated flash flood risk will continue across
the discussion area for the next 3-4 hours (through 12Z/7a central.

Discussion...A band of deep convection was moving very slowly
eastward at around 10-15 knots per radar mosaic imagery.  The band
was collocated with strong low-level convergence on the nose of a
~30 kt low-level jet across central ND, with convection rooted in
the mid-levels where ~6.5 C/km lapse rates exist.  The airmass is
also characterized by 1.5+ inch PW values that were combining with
slow storm motions to foster areas of 2 inch/hr rain rates (near
Rugby and near the international border at the intersection of ND
14 and ND 5).  While these rates were impressive (and approaching
2.5 inch FFG thresholds in spots), antecedent dry conditions and
low soil moistures (per NASA Sport) were likely limiting the
extent of flash flood potential across the region.

These trends are expected to continue for the next 3-4 hours or
so.  SPC Mesoanalysis depict that the low-level convergence
supporting ongoing convection will slacken gradually this morning
as flow weakens to around 15 knots or so.  Downstream instability
values are weaker too (~6 C/km lapse rates, negligible
surface-based instability), also supporting eventual weakening.
The ongoing flash flood threat should remain isolated through
12Z/7a central.

Cook

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

ATTN...WFO...BIS...FGF...

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

LAT...LON   49050049 48949934 48909822 48219786 47479802
            47729990 48240082