FXUS65 KTWC 230902
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
202 AM MST Sun Aug 23 2026

.SYNOPSIS...Isolated to scattered afternoon and early evening 
thunderstorms through Monday, then reduced storm chances through 
much of the remainder of the work week. Strong, gusty winds and 
locally heavy rainfall will be possible with any thunderstorm. High 
temperatures will remain above normal through the week with an 
Extreme Heat Warning in effect for much of southeast Arizona. 

&&

.DISCUSSION...The main weather story for this week will 
continue to be the heat with an extended stretch of near record to 
record high temperatures starting Tuesday. This is all courtesy of 
an anomalously strong area of high pressure aloft. This high is 
currently centered over New Mexico and will briefly weaken on Monday 
for some slight 'cooling', but that will be short lived as the high 
re-strenthens starting Tuesday and shifts west into Arizona 
Wednesday, continuing into the weekend. The high pressure aloft will 
peak in intensity mid to late week with 500mb heights up to around 3 
standard deviations above normal. The Extreme Heat Warning is in 
effect for much of southeast Arizona through Saturday.  

Outside of the heat concerns, we've still got some monsoonal 
moisture across our area. Latest IR satellite imagery shows 
continued southeast flow across our forecast area with clear to 
partly cloudy skies. Our focus for storms today will once again 
mostly be on locales from Tucson south and westward (where the 
greatest instability is) as drier air remains closer to the NM 
border. Main concern with these storms will continue to be wind with 
a secondary isolated threat for heavy rain/flash flooding. Included 
some patchy blowing dust into the forecast later this afternoon into 
the evening from the T.O. Nation north into Pinal County with some 
gusty outflow winds there. A very similar setup for storm activity 
is expected on Monday before a more notable downward trend in 
convection starting Tuesday and continuing through the rest of the 
work week with storm chances mostly hugging right along the Int'l 
border and White Mountains. Generally little if any activity 
elsewhere as subsidence and drier air aloft limits storm chances. 
There are some hints of an uptick in convection next weekend as 
moisture increases and the high might shift just enough for more 
favorable northeast flow. 

&&

.AVIATION...valid through 24/12Z. 
Generally FEW-SCT clouds 9-13k ft AGL through the forecast period 
with locally BKN clouds between 23/21Z and 24/09Z. Expect isolated 
to scattered SHRA/TSRA this afternoon into evening, mainly west of a 
KFHU-KSAD line, diminishing by 24/06Z. Confidence is too low for 
terminal impacts for KTUS/KOLS to include in TAFs at this time. 
Gusts in excess of 40 kts are expected with the stronger storms. 
Otherwise surface winds light and terrain driven. Aviation 
discussion not updated for TAF amendments. 

&&

.FIRE WEATHER...Isolated to scattered thunderstorms expected through 
Monday, with the exception of along the NM border where mainly dry 
conditions are expected. Thereafter, reduced chances for 
thunderstorm activity for most of southeast Arizona for the rest of 
the work week, though some isolated storms will continue along the 
immediate Int'l border and White Mountain region. Temperatures will 
remain well above normal through most of the week with Monday being 
the coolest day of the period. Drier conditions will return in the 
middle of the week with minimum relative humidity values mainly 10-
18 percent in the valleys and 20-30 percent. Winds will generally 
remain less than 15 mph and terrain driven through the week. 

&&

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

$$


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