372
FXUS65 KTWC 111921
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1221 PM MST Mon May 11 2026

.SYNOPSIS...Hot temperatures will continue through Tuesday, with
high temperatures 10 to 15 degrees above normal. High temperatures
will then lower several degrees mid to late week, but still remain
above normal. Otherwise, there will be enough mid-level moisture for
some afternoon and evening cloud build-ups mainly from Tucson south
and eastward through Wednesday, resulting in a slight chance of
virga or dry thunderstorms.

&&

.DISCUSSION...A ridge of high pressure centered over north central
Arizona will result in hot temperatures, with high temperatures
topping out 10-15 degrees above normal. Most lower elevation
locations from Tucson westward and in the Gila River valley will be
in Moderate HeatRisk through Tuesday, with localized Major HeatRisk
in the far western deserts around Ajo and Organ Pipe today. Highs
peak today at 101-103 degrees in the Tucson metro and 105-107
degrees across central/western Pima County.

As the ridge slides off to our east later tonight through Wednesday,
the steering flow turns south/southeasterly which will advect some
mid-level moisture into our eastern areas (mainly south and east of
Tucson). Measurable rainfall chances remain very low. However, there
may be enough moisture for some virga, a few lightning strikes/dry
thunderstorms and/or some gusty outflow winds. Thunder probabilities
are in the 5-15 percent range mainly along the International Border
and Chiricahua Mountains this evening and in the higher terrain
south and east of Tucson Tuesday and Wednesday. High temperatures
will lower 1-4 degrees Tuesday and an additional 2-5 degrees on
Wednesday, but will still be 6-8 degrees above normal on Wednesday.

The mid level moisture then gets shunted off to our east late
Wednesday night and Thursday, as a storm system tracks across the
northern tier of states and an associated trough axis moves across
the Great Basin turning the steering flow southwesterly. This system
will result in elevated southwest to west winds Wednesday afternoon
and Thursday, with wind speeds of 15-20 mph and gusts to around 30
mph. Heights lower behind this system Thursday and Friday, which
will shave another couple of degrees off high temperatures and highs
top out at 4-6 degrees above normal.

High pressure builds back into the region to start the upcoming
weekend, with the models diverging late in the weekend into early
the following week. Overall, the Ensembles and Clusters favor west
coast troughing by late in the weekend, although the strength/depth
of this troughing is still uncertain at this time.

&&

.AVIATION...Valid through 13/00Z.
FEW-SCT clouds at 12k-15k ft AGL from KTUS eastward thru 12/04Z and
then again aft 12/17Z, with clear skies/SKC conditions between
12/04Z and 12/17Z. There is a slight chance for some virga/dry
thunderstorms mainly over the higher terrain south and east of KTUS
thru 12/04Z and then again aft 12/19Z, but these are unlikely to
impact any terminals. SFC wind generally ELY/SELY at 12 kts or less
thru 12/19Z. Aft 12/19Z, SFC wind SWLY/WLY at 8-13 kts and ocnl
gusts to 15-20 kts. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...High temperatures through Tuesday will be 10-15
degrees above normal. High temperatures will then lower several
degrees mid to late this week, but still remain above normal. Min
relative humidity values through the upcoming weekend will generally
be in the 6-14 percent range in the valleys and 10-20 percent in the
mountains. 20-foot winds on Tuesday and Friday through Sunday will
be 15 mph or less, with typical afternoon and early evening gusts to
around 25 mph due to strong surface heating. Elevated southwest-west
winds are expected Wednesday and Thursday, with speeds of 15-20 mph
and gusts to around 30 mph. Enough mid level moisture will be in
place south and east of Tucson this evening through Wednesday for
some cloud build-ups and a slight chance (5-15 percent) of dry
thunderstorms and/or gusty outflow winds.

&&

.CLIMATE...Near record highs Today/Monday May 11

Date                         May 11
                          Fcst Rcd/Year
Tucson Intl Airport       102  105/1996
Ajo                       107  107/1934
Organ Pipe Cactus         107  109/1996
Picacho Peak              102  108/1996

&&

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

&&

$$

Zell

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