755
AWUS01 KWNH 252053
FFGMPD
AZZ000-UTZ000-NVZ000-260245-

Mesoscale Precipitation Discussion 0495
NWS Weather Prediction Center College Park MD
448 PM EDT Tue Jun 25 2024

Areas affected...Northern Arizona and Southern Utah

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

Valid 252047Z - 260245Z

SUMMARY...

Slow-moving thunderstorms have developed along the Mogollon Rim
into southern Utah associated with the thermal low. Flash flooding
will be likely as these storms move over flood-sensitive areas.

DISCUSSION...

Slow-moving thunderstorms across the Mogollon Rim region are
tapping into well above normal atmospheric moisture to produce
storms capable of rainfall rates to 1.5 inches per hour. PWATs of
1 to 1.5 inches per hour are 3-4 sigma above normal for this time
of year. Thus, the storms have plenty of moisture to work with as
they form along the upslope areas of the Mogollon Rim in weak
south to southwesterly flow. Due to the weak steering flow, the
storms are very slow-moving, giving them ample time to cause
locally considerable flash flooding.

Flood sensitive areas such as any slot-canyons, arroyos, urban
areas, will be particularly vulnerable to rapid-onset flash
flooding. Note that areas downstream of the storms are likely to
see flash flooding, even if it`s not raining in that area directly
overhead, as canyons rout a lot of the rainwater into small
spaces, resulting in rapid rises.

Note: While still recovering from the recent data outage, the
accompanying graphic is missing current weather data.

Wegman

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

ATTN...WFO...FGZ...PSR...SLC...TWC...VEF...

ATTN...RFC...CBRFC...CNRFC...NWC...

LAT...LON   38221340 38191115 37811090 37221101 34781073
            34140971 33680907 32990918 32990996 33511106
            34181211 34691322 35521506 36631561