FXUS65 KTWC 081935
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1235 PM MST Wed Jul 8 2026

.SYNOPSIS...Isolated to scattered showers and thunderstorms are
expected each day this week, with the potential for an increase
in storm coverage over the weekend. Hot temperatures for much 
of the week before cooling off this weekend.

&&

.DISCUSSION...Very little change in the forecast versus 24 hours 
ago. High pressure aloft extends from west of the northern Baja 
Peninsula northeast into western New Mexico. By Thursday and Friday 
the upper high will shift westward when it will be centered over the 
eastern Pacific through the northern Baja and into western Arizona. 
Over the weekend, the monsoon high shifts northeastward to north of 
the Four Corners into the central/high plains. 

With the upper high nearly overhead or very close by, Heat will be a 
concern through Thursday. High temperatures will top out 4-7 degrees 
above normal and an Extreme Heat Warning is in now effect through 8 
pm MST Thursday. The Extreme Heat Warning is in effect for the much 
of Pima County, south-central and southeast Pinal County and the 
Gila River Valley of Graham County. Moderate HeatRisk covers much of 
southeast Arizona through Thursday, with pockets of Major HeatRisk 
in the warning area. For more information on this product, please 
refer to PHXNPWTWC. 

Precipitable Water values currently range from 0.80" along the New 
Mexico state line to around 1.35" over central/western Pima County. 
The higher PW values are forecasted to get shunted east/southeast of 
Tucson Thursday into Friday as the upper high lifts northeast across 
the state. By Saturday and Sunday, PW values increase from near 1" 
in the White Mountains to between 1.3"-1.5" from Tucson southward 
along the International Border. Isolated to scattered thunderstorm 
chances today/tonight will be roughly east of a line from Oracle to 
Sells. The steering flow remains northeast to southwest at 10-15 
mph. The main threats will be gusty outflow winds to 40-45 mph, 
blowing dust along Interstate 10 in both Pinal and Cochise counties 
and localized heavy rainfall with the strongest storms. On Thursday 
and Friday, the thunderstorm coverage will shift slightly eastward, 
roughly east of a line from Safford to Tucson to Nogales.  

By this weekend, the steering flow shifts to an east to west 
direction, as the upper high becomes centered north/northeast of the 
Four Corners. Given the forecasted increase in PW's, Flash Flooding 
will become a concern. WPC has already issued an Excessive Rainfall 
Outlook for Saturday (Day 4), which highlights much of southeast 
Arizona in a Marginal Risk. Thunderstorm chances and coverage 
increase over the weekend to include all of southeast Arizona, 
including central and western Pima County. In addition, mid-level 
steering flow looks favorable for the potential for some clustering 
of storms and/or organized convection which could lead to an 
enhanced severe threat. This active pattern then continues into the 
early part of next week. High temperatures over the weekend will 
lower to right around normal, which is the lower 100s in the lower 
deserts from Tucson westward and in the Gila River Valley, with mid 
to upper 90s in the lower elevation locations of Santa Cruz and 
Cochise counties. By early next week, forecasted high temperatures 
will lower to 1-3 degrees below normal. 

&&

.AVIATION...Valid through 10/00Z.
FEW-SCT (locally BKN) clouds at 8k-11k ft AGL and ISOLD-SCT -SHRA/
-TSRA. There is the potential for outflow winds up to 45 kts thru 
09/04Z. Clouds and storms diminishing between 09/04Z and 09/17Z. Aft 
09/19Z through the end of the forecast period, SCT-BKN clouds at 8k-
11k ft AGL and ISOLD-SCT -SHRA/-TSRA mainly east of KTUS. Outside of 
any thunderstorm outflows, SFC wind less than 12 kts, favoring a 
WLY/NWLY direction during the afternoon/early evening hours and 
variable in direction at other times. Aviation discussion not 
updated for TAF amendments.

&&

.FIRE WEATHER...Above normal high temperatures (4-7 degrees) through 
Thursday, with highs lowering to around normal over the upcoming 
weekend. Min RH values in the lower elevations in the 13-20 percent 
range through Friday, increasing 5-10 percent by late in the weekend 
into early next week. Outside of any thunderstorm outflow winds, 20-
foot winds will generally be less than 15 mph into early next week. 
There will be a daily chance of showers and thunderstorms mainly 
during the afternoon/evening hours through Friday. There is the 
potential for increasing thunderstorm chances and coverage this 
weekend into early next week.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Extreme Heat Warning until 8 PM MST Thursday for AZZ501-502-
  504>506-509.

&&

$$

Zell

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