666
AWUS01 KWNH 161955
FFGMPD
COZ000-NMZ000-UTZ000-170053-

Mesoscale Precipitation Discussion 1024
NWS Weather Prediction Center College Park MD
354 PM EDT Mon Sep 16 2024

Areas affected...in and near southwest CO

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

Valid 161953Z - 170053Z

Summary...Thunderstorms with heavy rainfall are expected to move
into the area over the next several hours.  Hourly rain totals up
to 1.5" are possible, which would be problematic in steep terrain,
arroyos/dry washes, burn scars, and slot canyons.

Discussion...A deep upper-level trough across the West has led to
the formation of a boundary moving through eastern AZ and along
the UT/CO border at its leading edge which is spurring some shower
and thunderstorm development.  Clouds are eroding and those that
exist are becoming more convective in appearance in recent GOES
Veggie Band imagery.  Precipitable water values are ~0.75",
sufficiently moist considering the elevation, with ML CAPE values
of 500-1500 J/kg, highest near the Four Corners.  Effective bulk
shear across the region is impressive, in the 40-50 kt range.  CIN
appears negligible.

Guidance has a signal for heavy rainfall in the topography of
southwest CO through 00z before fading thereafter, which could be
due to the movement of the aforementioned boundary and related
erosion of the instability pool near the Four Corners.  In the
meantime, convection with possible mesocyclones could lead to
hourly rain totals to 1.5" where rain is most persistent due to
either training, backbuilding, or cell mergers.  This would be
problematic is any steep terrain, arroyos/dry washes, burn scars,
and slot canyons.

Roth

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

ATTN...WFO...ABQ...GJT...PUB...

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

LAT...LON   38480817 37940652 36860591 36560608 36480666
            36860872 37290937 37970923