746
ACUS11 KWNS 140035
SWOMCD
SPC MCD 140034
AZZ000-140230-

Mesoscale Discussion 1666
NWS Storm Prediction Center Norman OK
0734 PM CDT Sun Jul 13 2025

Areas affected...parts of southeastern Arizona

Concerning...Severe potential...Watch unlikely

Valid 140034Z - 140230Z

Probability of Watch Issuance...5 percent

SUMMARY...Thunderstorm activity accompanied by a few strong to
locally severe surface gusts may impact the Greater Tucson area by
7-8 PM MST.

DISCUSSION...Although convective inhibition is strong across the
strongly heated and deeply mixed boundary layer across the lower
deserts, latest objective analysis indicates that inhibition across
elevations around Tucson is much more modest in the peak afternoon
heating.  A corridor of modest CAPE appears to linger from from
northeast of the Greater Tucson area into areas just to the
southwest, generally aligned with the 10-20 kt east-northeasterly
mid-level steering flow for convection.

A small cluster of storms which initiated across the mountains of
northeastern Cochise Country, perhaps aided by outflow from a
dissipating cluster across the higher terrain of southwestern New
Mexico, appears to be in the process of gradually propagating off
(west/southwest of) the higher terrain.  It appears possible that
forcing for ascent along the associated outflow could support
thunderstorm development into and across the Greater Tucson area by
around 02-03Z, before inhibition with the loss of daytime heating
becomes increasingly suppressive of thunderstorm development.

As this occurs, with the sub-cloud layer to the surface still
characterized by large temperature-dew point spreads (including
30-40+ F at the surface), even with some cooling off of current
temperatures in excess of 100F, the potential for a few strong to
severe outflow gusts seems likely to continue.

..Kerr/Thompson.. 07/14/2025

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   32151123 32251047 32121017 31880969 31630966 31381042
            31411101 31891146 32151123

MOST PROBABLE PEAK WIND GUST...55-70 MPH