Severe Thunderstorm Warning 46, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
102 PM MST Fri Aug 15 2025

.SYNOPSIS....Isolated to scattered thunderstorms will initially
develop across Cochise county this afternoon, becoming scattered
to numerous as they expand northwest toward the Tucson Metro Area.
These storms will then build toward the west and southwest late
this afternoon into this evening as deeper moisture in the lower
deserts fuels additional storm development. Given the ample
atmospheric moisture available for these storms, the main impact
with the storms today will be the potential for heavy rainfall,
especially from Tucson southward. Otherwise, daily isolated to
scattered showers and thunderstorms will persist into next week
with day to day variability in intensity and chances.

&&

.DISCUSSION... Showers from this morning continue to move out of
the area now pushing into northern Graham and Greenlee counties.
Storms and showers this afternoon are still on the docket with
showers already starting to form south of Tucson. Isolated to
scattered storms will develop initially south of Tucson becoming
more widespread into central Pima county and western Cochise
county. The main concern associated with these storms and showers
is locally heavy precipitation leading to flash flooding and
occasionally gusty winds with stronger storms. Due to significant
forecast PWATs around 1.4 to 1.6 inches and continual showers and
storms, the Weather Prediction Center (WPC) has placed eastern
Pima, western Cochise, and Santa Cruz counties in a slight risk
for excessive rainfall this afternoon. These storms and showers
will continue into the evening hours lessening to be just
isolated to scattered showers overnight. Accumulated rainfall
ranges from 0.75 to 1 inches with locally higher amounts.

Over the next several days, there should be enough moisture for
isolated coverage/low-grade Monsoon pattern Sunday into early next
week. After that, we begin to see the upper high center move back
toward our neck of the woods, eventually making its way to the
Four Corners region by the middle of next week. If we can import
some deeper moisture from the east-southeast into Southeast
Arizona, we may see an increase in activity. However at this
point, the deeper atmospheric moisture may end up being a plume of
higher precipitable water values (1.50+ inches) moving up the
Gulf of California begining Tuesday, filling into the lower
deserts once again. Unfortunately, the main impact of the upper
high moving back into Arizona the second half of next week may be
the increase in afternoon high temperatures leading to Major
HeatRisk by Wednesday/ Thursday.

&&

.AVIATION...Valid through 17/00Z.
FEW to SCT clouds AOA 8k to 12k ft AGL KTUS southeastward. Clouds
become SCT to BKN northeast of KTUS including KSAD AOA 7k to 11k
ft AGL. Clouds will continue to develop KTUS southward into the
afternoon becoming more SCT as cumulus clouds develop AOA 7k to
10k ft AGL. ISOLD-SCT -SHRA/-TSRA will initially develop across
Cochise and Santa Cruz (including KOLS and KDUG) between
15/20Z-12Z, becoming SCT-NUM -SHRA/-TSRA toward KTUS with
occasional VSBY 3-5SM SHRA/TSRA with cigs BKN 5-8k ft AGL as they
expand northwest toward KTUS aft 15/21Z. These storms will then
build toward the W/SW late this afternoon into this evening.
Although gusty and erratic winds 35-40 kts will be possible near
any TS, surface winds should remain below 15 knots with the
occasional afternoon gusts up to 20 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Southeast Arizona will be in an active Monsoon
pattern today and Saturday, with the best chances for wetting
rain showers and thunderstorms occuring today. After Saturday,
there will be daily chances for thunderstorms and wetting rain
showers into next week. Min RHs will generally be around 25
percent in the lower elevations and 45+ percent in the mountains
today and Saturday. Sunday, min RHs will start to drop back down
to the 15-20 percent in the lower locations and 20-30 in the
mountains into the new week. Winds will generally be less than 15
mph with typical afternoon gusts up to 20 mph into next week.
Monsoon moisture is projected to return late next week to provide
higher chances for thunderstorms and rain showers. Temperatures
will be around normal through this weekend, trending above normal
the second half of next week.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&

Malarkey

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