Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
505
FXUS65 KTWC 052146
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
246 PM MST Tue Aug 5 2025
.SYNOPSIS...Very hot weather will continue this week with high
temperatures near monthly August records for some locales Wednesday
and Thursday. A low grade monsoon pattern returns today with slight
chances of precipitation each afternoon and evening through Thursday
mainly along the International border south of Tucson and in the
White Mountains. Precipitation chances then begin to increase across
the rest of southeast Arizona Friday into the weekend.
&&
.KEY MESSAGES...
-Dangerously hot temperatures continue across southeast Arizona in
a multiday anomalous heatwave. Extreme Heat Warning in effect
through 8 PM Friday evening. Potential for record to near-record
high temperatures exists for multiple locations.
-Isolated shower and thunderstorm activity possible today mainly south
and west of Tucson. Storms that do develop may produce gusty
outflow winds, blowing dust, and brief moderate to heavy
rainfall.
-Low grade Monsoon pattern will continue to support extreme heat
with limited chances for and coverage of shower and thunderstorm
activity. Moisture returns by the weekend with increasing chances
for precipitation and decreasing temperatures.
&&
.DISCUSSION...Showers have started forming over high terrain areas
in Santa Cruz County as well as on the eastern side of the Galiuro
Mountains in southwest Graham County. As strong daytime heating
continues, expect shower and thunderstorm development to continue
growing upscale starting with cloud buildups over the higher
terrain. Isolated showers and thunderstorms may then push north into
eastern Pima County and west into T.O. Nation during peak heating.
Any stronger storms that are sustained may be capable of strong
gusty winds resulting in blowing dust. However, we are in the
vicinity of a strong upper level high which could limit shower and
thunderstorm development, especially along the Arizona and New
Mexico state line.
The threat for extreme heat continues with near-record to record
high temperatures likely through the end of the work week across
southeast Arizona, especially tomorrow and Thursday. Even all time
August monthly temperature records are in jeopardy for many locales.
See climate section below for additional information. Extreme Heat
Warning remains in effect through Friday evening. Use extreme
caution when spending time outdoors. Wear light colored and loose
fitting clothing. Take plenty of breaks. Stay hydrated and remain
indoors in an air conditioned space, especially during the hours of
peak daytime heating.
Low grade monsoonal storm activity continues Wednesday and Thursday
with a continued focus closer to the International Border and in the
White Mountains. On Friday, the worst of the heat will begin to
subside with highs 3 to 5 degrees lower than Thursday. Despite the
cooling trend, major HeatRisk will continue well into Friday
afternoon and early evening. Thus, the Extreme Heat Warning remains
in effect until 8 pm Friday. Expect an uptick in moisture heading
into the weekend from Sonora and the Gulf of California resulting in
increasing precipitation chances and decreasing temperatures.
&&
.AVIATION...Valid through 07/00Z
SCT to locally BKN clouds 10-15k ft AGL mainly to the south and
southwest of KTUS this afternoon gradually diminishing after 06/03Z
this evening. Isolated -SHRA/-TSRA possible mainly to the south and
southwest of KTUS through 06/03Z. Gusty winds expected in and near
-SHRA/-TSRA. Otherwise, SFC winds WLY/NWLY at 8-12 kts with
occasional gusts up to 20 kts becoming light and variable after
06/05Z. Tomorrow, -SHRA possible in the vicinity of KOLS between
06/20Z and 07/02Z with SCT to locally BKN clouds 10-15k ft AGL. SFC
winds tomorrow mainly WLY/NWLY at 8-12 kts with gusts around 20 kts.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Very hot temperatures all this week, as highs peak
at 8-14 degrees above normal Wednesday and Thursday. A return to a
low grade monsoon pattern today through Thursday, focused along the
International border south to southwest of Tucson and in the White
Mountains, then expands to the rest of southeast Arizona by Friday
and the weekend as more typical monsoon precipitation chances
return. Min RH values areawide will continue around 8-15 percent
through Thursday, then 14-23 percent starting Friday. Mountain
readings climb into the 20-30 percent range Saturday into early next
week.
&&
.CLIMATE...All-time August record highs including date and
forecast highs for Wednesday and Thursday.
WED FCST THU FCST
Ajo 118 on August 28, 2023 114 113
Organ Pipe Cactus 116 on August 5, 1995 114 111
Picacho Peak 114 on August 28, 1998 110 110
Tucson Intl airport 112 on August 1, 1993 112 112
Safford (town) 110 on August 16, 2024 110 109
Willcox 108 on August 1, 2020 106 105
Nogales (town) 107 on August 5, 2023 106 104
Douglas airport 106 on August 5, 2023 104 103
Sierra Vista 105 on August 6, 2023 102 101
DAILY RECORD HIGH TEMPERATURES FOR SELECT CITIES THIS WEEK.
DATE Aug 05 Aug 06
FCST RCD/YR FCST RCD/YR
TUCSON INTL AIRPORT 109 110/2023 112 109/2018
AJO 110 114/1969 114 113/2019
ORGAN PIPE CACTUS 109 116/1995 114 113/1995
PICACHO PEAK 111 113/1995 110 113/1995
SAFFORD AG STATION 108 110/2023 110 108/1995
SIERRA VISTA FD 101 103/2023 102 105/2023
TOMBSTONE 102 103/1995 102 104/2023
WILLCOX 104 105/2018 106 107/2023
DATE Aug 07 Aug 08
FCST RCD/YR FCST RCD/YR
TUCSON INTL AIRPORT 112 108/1995 107 108/2012
AJO 113 114/2018 108 112/2001
ORGAN PIPE CACTUS 111 113/1995 106 113/1995
PICACHO PEAK 110 113/1995 109 110/1995
SAFFORD AG STATION 109 106/2018 107 106/1995
SIERRA VISTA FD 101 101/2018 98 99/2012
TOMBSTONE 101 103/2018 100 102/1995
WILLCOX 105 106/2018 102 106/2012
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM MST Friday for AZZ501>509-515
&&
$$
DVS
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