Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Sat Aug 16 2025 02:48:30

AWUS01 KWNH 160245
FFGMPD
AZZ000-160730-

Mesoscale Precipitation Discussion 0941
NWS Weather Prediction Center College Park MD
1044 PM EDT Fri Aug 15 2025

Areas affected...South-central to Southeast Arizona...

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

Valid 160245Z - 160730Z

SUMMARY...Slow moving thunderstorms to track slowly southwest
perhaps with short-term training/repeating resulting in localized
2"+ totals and possible localized flash flooding conditions.

DISCUSSION...Fading GOES-W Visible imagery loop shows two NW to SE
outflow boundary arcs across AZ, one up on the San Francisco
Plateau, the other through the Sonoran Desert into southeast AZ
and northeast Sonora, Mexico.  GOES WV suite continues to depict a
deep long wave trof with slight negative tilt orientation across
Southern California with broadening diffluent region of
southwesterly flow across much of the Colorado River Basin into AZ
providing deep layer divergence across the region.=20

As sunset was approaching, increasing southerly flow off the Sea
of Cortez surged moisture through the surface to 850mb layer
across Mexico into south-central AZ.  This increased moisture flux
convergence along the boundary providing solid isentropic ascent
to break out clusters of thunderstorms. The dominant reaching -70C
across southern Pima county.  RADAR and EIR continues to show
expansion/intensification within the cluster.   RAP analysis
denotes that MUCAPE values remain around 2000-2500 J/kg,
especially further west to fuel these cells.  LLJ of 25kts slowly
reduces along the eastern edge of the jet and propagation vectors
suggest slow southeastward evolution along the stalling outflow
boundary (though the boundary will likely kick southward with time
given cold pool generation).  Surface Tds in the low to mid 60s
and total PWats through the lower cloud support PWat values near
1.5-1.75" and should support rates of 1.75"/hr, occasionally
ticking up to 2" where cores can merge for short duration.=20=20
Duration is likely to be 1-2 hours with similar rates, so
localized 1.5-2.5" totals are possible across south-central
Arizona and toward the Santa Cruz county border with Mexico.  As
such, localized incidents of flash flooding will remain possible
through the early overnight period.

Gallina

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!7S_MaR-y33KOHbIuy4c0dLYta8rZ8c4IVyIuO3A1_RE6ZyVrwS4ykbm1t46q908Jp_-J=
EB9quBP7Ee5rPttqbs-aWGw$  for graphic product...

ATTN...WFO...TWC...

ATTN...RFC...STR...NWC...

LAT...LON   32511194 32261127 31751065 31441001 31261001=20
            31251064 31301126 31451163 31671225 31931252=20
            32351247=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email
Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

.