442
AWUS01 KWNH 151939
FFGMPD
NMZ000-AZZ000-160137-

Mesoscale Precipitation Discussion 1016
NWS Weather Prediction Center College Park MD
339 PM EDT Sun Sep 15 2024

Areas affected...southeastern Arizona through central New Mexico

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

Valid 151937Z - 160137Z

Summary...Thunderstorms continue to produce 1-2 inch rainfall
amounts across portions of the Upper Mississippi Valley.  Isolated
flash flood potential continues with this activity.

Discussion...Recent radar mosaic imagery depicts a mature,
forward-propagating convective complex extending from near Eau
Claire to Mason City.  A few cell mergers have been noted with the
complex over the past couple hours, and local rain rates continue
to approach 2 inches/hr in spots despite appreciable forward
movement.  The immediate downstream airmass remains sufficiently
moist/unstable for strong convection (2000+ J/kg MLCAPE and 1.5
inch PW values), and current trends suggest that spots of 1+
inch/hr rain rates should continue to materialize for at least
another 2-4 hours or so as the complex migrates eastward.

The greatest concern for isolated flash flood potential exists as
storms traverse central and eastern Wisconsin (generally from Eau
Claire eastward to Green Bay).  Although some uncertainty exists
with respect to eastward extent of the complex, these areas
currently have the lowest FFG thresholds (around 1-1.5 inch/hr)
and the greatest chance for those thresholds being exceeded on an
isolated basis.  Destabilization is slow to occur across
northeastern Wisconsin, and it appears that the northern portions
of the complex may undergo weakening (and lessening flash flood
potential) especially north of Wisconsin State Highway 29.  Higher
FFGs (~2-3 inch/hr) across southwestern Wisconsin suggests an even
more isolated/spotty flash flood threat in these areas through 06Z.

Cook

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

ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC...

ATTN...RFC...ABRFC...CBRFC...WGRFC...NWC...

LAT...LON   36620685 36310517 35330474 34370485 33480572
            32930692 31950803 31360853 31441153 33371128
            36100945