FXUS65 KTWC 190857
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
157 AM MST Tue May 19 2026

.SYNOPSIS...A storm system to our north will bring southwesterly breezes
today and tomorrow. Temperatures will be slightly below to near
normal for the rest of the week with Minor Heat Risk. 


&&

.DISCUSSION...This morning's water vapor imagery shows a weather
system over Utah where it will linger over the region today and
tomorrow. This system will continue southwesterly breezes this 
afternoon and again tomorrow. The speeds will be less than the 
previous days, but enough to raise elevated to brief near 
critical fire weather conditions for Cochise County. 

Over the next two days, ensemble models show a low pressure
circulation over Baja California, separating itself from the
main trough currently over the intermountain west. This low will
inject upper level moisture into the area, leading to high
clouds starting later today. Temperatures will be near normal
with Minor HeatRisk for the region. By the weekend, the 
moisture will work its way down the atmosphere, sitting around 
700mb for the eastern areas of Tucson. There are some 
uncertainty on the amount of moisture making its way down and 
how far west it would be. The lower levels will remain dry.
Memorial Day weekend is shaping up to cloud build ups, non- 
zero chance for a dry thunderstorm, and gusty erratic winds from
any virga. Otherwise, temperatures will stay near normal with
Minor HeatRisk. 


&&

.AVIATION...valid through 20/12Z. 
Mostly SKC this morning with high cirrus. By 19/18Z, SCT-BKN 
clouds at or around 20K feet AGL and another FEW-SCT layer at 
or around 15K feet AGL through most of the forecast period. SFC
winds this morning, and again after 20/03Z, will be less than 
12 kts and terrain driven. By 19/18Z, southwesterly winds at 
12-20 kts with gusts 25-30 kts. The strongest winds will be 
south and east of KTUS, especially at KDUG terminal. Aviation 
discussion not updated for TAF amendments. 

&&

.FIRE WEATHER...
Dry and breezy conditions today and tomorrow, resulting in 
elevated fire weather conditions for areas east and south of 
Tucson with brief near critical conditions existing in the 
southeastern portion of Cochise County. By the end of the week, 
winds will be generally be less than 15 mph with min relative 
humidities sitting in the teens to the mid-20s. Upper level 
moisture will be moving into the region starting Saturday, 
leading to mainly virga and cloud build ups to a non-zero chance
for a dry thunderstorm in the higher terrain.


&&

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

&&

$$

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