FXUS65 KTWC 071944
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1244 PM MST Tue Jul 7 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...High pressure aloft extends from west of the Baja 
Peninsula northeastward into the eastern Colorado. By Thursday and 
Friday the upper 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 northward to 
north of the Four Corners into the central 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 effect through 8 pm 
MST Wednesday. 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. The Extreme Heat Warning may need to be pushed 
out through Thursday and subsequent shifts will take a closer look 
at that. For more information on this product, please refer to 
PHXNPWTWC. 

Precipitable Water values hold nearly steady through Wednesday, with 
values ranging from 0.80" in the White Mountains to 1.25" along the 
International Border. PW values are then forecasted to drop around 
0.25" 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 around 1.5" along the International 
Border. Isolated to scattered thunderstorm chances will exist 
through Wednesday, roughly east of a line from Hannagan Meadow to 
Tucson to Nogales. The steering flow remains northeast to southwest 
over this period. The main threats will be gusty outflow winds to 40-
45 mph, blowing dust along Interstate 10 and localized heavy 
rainfall with the strongest storms. Thursday and Friday thunderstorm 
coverage should decrease a little and shift slightly eastward with 
lowering PW values and the upper high nearly overhead. 

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 more of a concern. In addition, thunderstorm coverage 
increases to include all of southeast Arizona, including central and 
western Pima County. 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.  

&&

.AVIATION...Valid through 09/00Z.
FEW-SCT (locally BKN) clouds at 7k-10k and ISOLD-SCT -SHRA/-TSRA and 
the potential for outflow winds up to 45 kts thru 08/04Z. Clouds and 
storms diminishing between 08/04Z and 08/17Z. 08/17Z through the end 
of the forecast period, SCT-BKN clouds at 7k-10k and ISOLD-SCT 
-SHRA/-TSRA. Outside of 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 13-17 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 this work week. There is the 
potential for increasing thunderstorm chances and coverage this 
weekend. 

&&

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

&&

$$

Zell

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