Rio Rico, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

720
FXUS65 KTWC 121710
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1010 AM MST Tue Aug 12 2025

.SYNOPSIS...Isolated to scattered thunderstorms generally east
and south of Tucson today will be capable of strong thunderstorm
outflow winds with the potential for blowing dust along the
Arizona and New Mexico border. Storms will increase in strength
and coverage Wednesday across the majority of Southeast Arizona.
Otherwise, expect daily shower and thunderstorm chances into next
week with day to day variability in chances. High temperatures
will generally remain above normal this week, cooling Friday into
this weekend.

&&

.UPDATE...We are on track for a mid-grade monsoon day today
primarily east and south of Tucson. Main concerns will be isolated
to scattered showers and thunderstorms with the potential for
strong gusty outflow winds, blowing dust, and brief moderate to
heavy rainfall.

Upper pattern aloft favors storms generally moving from north to
south. Convective allowing models are hinting at storm initiation
around noon across the higher terrain of Santa Cruz and Cochise
counties with additional storms firing in the White Mountains in
northern Greenlee county. Precipitable water is leaning on the
lower end (0.8 to 1.2 inches from Tucson eastward) per latest GOES
imagery estimates over these areas. Consequently, I expect storms
to favor gusty winds rather than heavier rainfall. Higher
precipitable water values were located out over T.O. Nation and
western Pima county upwards of 1.5 inches.

Later this afternoon into the evening the initial storms focused
to the east of Tucson could result in more of an organized outflow
propagating west allowing for a few additional storms to
potentially develop. However, confidence in storms in the Tucson
Metro remains low at this time and will gain more insight from our
mid-morning rawinsonde.

&&

.PREV DISCUSSION... /issued 208 AM MST Tue Aug 12 2025/

The upper pattern this morning is defined by an upper (500-300
mb) ridge of high pressure positioned along the NRN CA/NV border,
with the 500 mb ridge axis extending SE into central Arizona. This
feature will move SE today into NW AZ by 00Z this afternoon. As
this happens, expect to see an area of deformation develop to the
east of Tucson which should help assist thunderstorm development.
The dry sub-cloud airmass represented by the PWAT values between
0.80 and 1.00 inches across Graham, Greenlee and Cochise counties
today will increase the potential for strong downdrafts/outflows
due to evaporative processes. The 12/00Z model soundings generally
indicate DCAPE values 1800-2000 J/kg along the Arizona/New Mexico
border, which would be strong enough for damaging thunderstorm
outflows/blowing dust concerns. The 12/00Z HREF indicates a
neighborhood (40 km) probability of wind gusts in excess of 30+
kts AOA 70 percent along the AZ/NM border and the International
border east of Nogales between 23Z and 04Z this evening. However,
although it is worth noting that the HREF has backed off on the
10% neighborhood probability of wind gusts in excess of 50 kts on
its previous (11/12Z) run, the current thinking is that given the
better upper-level support for thunderstorms, I would expect
localized damaging thunderstorm outflows of 50+ kts across Cochise
county.

Things start to really get interesting for Southeast Arizona
Wednesday as the 300 mb upper high center moves from NW AZ into
northern New Mexico by 00Z Wednesday afternoon with the 500 mb
high center staying put across northern AZ. This results in a
stronger NE mid-level flow across the majority of Southeast
Arizona which should help morph our pulse-type storms into
multi-cellular storm clusters. In addition, we will experience an
enhancement to the deformation field at 300 mb due to stretching
aloft. These two factors should be enough to result in an mid-to-
high grade Monsoon day across our CWA Wednesday, with the
potential for Tucson to get into the mix. The main impact from
storms Wednesday will be strong and gusty outflow winds/blowing
dust from Tucson east (due to the drier airmass), and heavy
rainfall from Tucson west due to the deeper PWAT values 1.20+
across the lower deserts.

The high center moves farther east Thursday and Friday, opening up
Southeast Arizona to the influence of the upper trough along the
West Coast. This should help shift the deeper moisture residing in
the lower deserts eastward, increasing the potential for heavy
rainfall across the central and eastern portions of the CWA. At
this juncture, it is hard to distinguish which day will be more
favorable for rainfall at this time. Thereafter, the upper high
moves back into the area from the east this weekend, with a Four
Corners high developing early next week. This should open up
Southeast Arizona to a more active pattern with impulses moving
along the southern periphery of this high into our neck of the
woods.

&&

.AVIATION...Valid through 13/12Z. SCT-BKN clouds at or around
10-14K ft AGL through 12/19Z, then SCT-BKN 8-12k ft AGL with
ISOLD-SCT -SHRA/-TSRA mainly E-NE of KSAD and S-SE of KTUS
through 13/05Z. Lingering -SHRA will be possible in the overnight
through 13/10Z. Gusty erratic winds up to 45 kts near any TS,
especially along the AZ/NM border and the International border in
Cochise county (near KDUG). Otherwise, surface winds should
remain below 15 knots. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...High temperatures will remain several degrees
above normal for the first half of the week and then near normal
this weekend. Daily chances for thunderstorms and wetting rains
through the week with daily variability in coverage and intensity.
Min RHs will generally be around 15-25 percent in the lower
elevations and 20-35+ percent in the mountains through Thursday,
increasing Friday and Saturday as deeper moisture tracks across
the area. Winds will generally be less than 15 mph with typical
afternoon gusts up to 20 mph into next week.

&&

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

&&

$$

Update...DVS

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