104
AWUS01 KWNH 272017
FFGMPD
COZ000-NMZ000-AZZ000-UTZ000-280215-

Mesoscale Precipitation Discussion 0506
NWS Weather Prediction Center College Park MD
416 PM EDT Thu Jun 27 2024

Areas affected...Portions of Western Colorado & Northwest New
Mexico

Concerning...Heavy rainfall...Flash flooding likely

Valid 272015Z - 280215Z

SUMMARY...Flash flooding likely as strong forcing coupled with
record atmospheric moisture fuels storms capable of heavy rain
rates to 2 inches per hour.

DISCUSSION...Numerous showers and thunderstorms have developed
across Utah, Arizona, and far western New Mexico this afternoon. A
strong shortwave trough moving east over the northern Rockies is
invigorating the atmosphere over the Four Corners. Storms capable
of rainfall rates as high as 2 inches per hour have developed, and
will continue to redevelop and form over western Colorado and
Northwest New Mexico into the afternoon. A major contributing
factor to the unusual nature of convection in this region are
record to near record precipitable water values from the 12Z
soundings this morning based on SPC Sounding Climatology in
Albuquerque, Grand Junction, and Salt Lake City. Thus, the storms
have unusually high amounts of moisture to work with, and the
shortwave trough will help those storms to organize as they
interact with the high terrain. Further, SBCAPE values of 1,000 to
2,000 J/kg already in place will continue to support strong
thunderstorm development through the afternoon and early evening.

The entire Four Corners region has above to well above normal soil
moisture from recent days of rain, so the organized and stronger
nature of the storms developing will combine with already higher
than normal river levels to result in scattered instances of flash
flooding. The storms that develop over local burn scars will cause
locally considerable and significant flash flooding over and
immediately downstream of the burn scars.

CAMs guidance shows portions of western Colorado will be targeted
by the convection currently over Utah as they move into Colorado
through this afternoon. The storms may be a bit faster moving this
afternoon as compared with previous days, but favorable dynamics
for training/backbuilding and the aforementioned wet soil
conditions as well as interaction with terrain will all support
flash flooding development.

Storms capable of causing flash flooding are likely to be ongoing
beyond the time of this MPD, so an updated MPD is expected around
02Z/8pm MDT.

Wegman

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

ATTN...WFO...ABQ...FGZ...GJT...PUB...SLC...

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

LAT...LON   40170736 39890669 39520649 38500623 37750574
            36500559 35490588 35160755 36090805 36860913
            37210943 38010869 38520904 38790961 39360996
            39571033 39690969 39930856