Sierra Vista, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

702
FXUS65 KTWC 261700
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1000 AM MST Thu Jun 26 2025

.SYNOPSIS...Afternoon and evening chances for showers and
thunderstorms are possible daily through Friday in eastern
locations, mainly closer to the New Mexico border. Temperatures
become hotter this weekend as conditions dry out. Moisture is
expected to increase next week and likely bring the start to the
monsoon season.

&&

.UPDATE...The sky was sunny to partly cloudy across southeast
Arizona this morning. GOES-19 PW imagery showed values between
0.80" and 1" along the AZ/NM border. This area will have a 10-30%
chance of storms this afternoon. Otherwise high temperatures will
be near normal. See discussion below for further details in the
7-day forecast.

&&

.DISCUSSION...Water vapor and satellite derived moisture
products this morning show an eastward expansion of dry air into
western Graham and Cochise counties. This has dropped forecast
thunderstorm coverage today to an area generally near and east of
a line from the White Mountains through Safford, Willcox, and
Sierra Vista. With satellite derived precipitable water values
generally near or below one inch and forecast CAPE values on the
weak side in this area, storm coverage and strength should be low.

Friday should see a marginally better environment in eastern
locations than today, but otherwise a similar storm strength
outlook will be in store. 00Z guidance does try to bring in weak
moisture into southern Pima and Santa Cruz counties Friday,
however this doesn`t look like a strong enough push at this moment
to add notable thunderstorm chances.

From this weekend into early next week an upper ridge is expected
to become centered over the Four Corners. By Monday this ridge
will likely have become amplified through the Pacific Northwest
and northern Rockies. NAEFS guidance shows 700mb temperatures over
Arizona around the 90th climatological percentile for this time
of year, highlighting the heat potential. Current forecast highs
for southeastern Arizona desert locations on Monday run from 108
to 112.

This ridge orientation next week will additionally favor the
increase in moisture needed to start the monsoon season. As
previously discussed the Climate Prediction Center has highlighted
southern Arizona for a high risk of heavy rainfall and flash
flooding during the second half of the week, which is when
ensemble models have heavily favored rich moisture to set in. In
the initial moisture push however there will still be
opportunities for thunderstorm impacts including strong wind
gusts, blowing dust, and lightning as early as Monday as the
incoming moisture interacts with the hot and initially dry
antecedent atmosphere.

&&

.AVIATION...Valid through 27/12Z.
FEW clouds at 10k feet, otherwise SKC through 26/18Z. FEW-SCT
cumulus at 10k feet with isolated to scattered showers and
thunderstorms mainly near and east of a KSAD- KFHU line after
26/18Z, diminishing after 27/03Z. Isolated gusts up to 40 kts with
stronger cells. Otherwise winds light and under 12 kts with an
occasional afternoon gust up to 20 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Chances for isolated to scattered showers and
thunderstorms today and tomorrow east of Tucson. Minimum relative
humidities from 10 to 20 percent today and tomorrow, with a drying
and warming trend this weekend. Winds generally light and under
15 mph with isolated gusts up to 45 mph under any thunderstorm
through Friday. Moisture should begin to arrive next week and
bring a start to the monsoon season across southeastern Arizona.

&&

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

&&

$$

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson