Blowing Dust Advisory 9, NWS Tucson, AZ

595 
WWUS75 KTWC 212305
NPWTWC

URGENT - WEATHER MESSAGE
National Weather Service Tucson AZ
405 PM MST Wed Jul 21 2021

AZZ501-502-220015-
/O.CAN.KTWC.DU.Y.0009.000000T0000Z-210722T0300Z/
Western Pima County-Tohono O'odham Nation-
405 PM MST Wed Jul 21 2021

...BLOWING DUST ADVISORY IS CANCELLED...

Little additional storm and blowing dust activity is expected west
of Tucson.

$$

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Area Forecast Discussion
National Weather Service Tucson AZ
259 AM MST Wed Jul 21 2021

.SYNOPSIS...An approaching weather system from the east will bring
widespread showers and thunderstorms to the area, especially from
Thursday evening through late Saturday. Locally heavy rainfall
combined with a saturated ground from recent rains may result in
flash flooding and flooding by Saturday night. Thereafter, a
decrease in daily shower and thunderstorm activity can be
anticipated Sunday afternoon into early next week. Otherwise, high
temperatures will be near normal with the exception of Friday into
the weekend when below average readings can be expected.

&&

.DISCUSSION...An interesting weather pattern will evolve Thursday
into the weekend as an upper low approaches from the east and
becomes quasi-stationary over east-central AZ/west-central NM late
Friday through late Saturday. This scenario resembles an historic
flooding and debris flow event in SE AZ which played out nearly 15
years ago during the last few days of July into August 1st of the
2006 monsoon season. That said, have posted a flash flood watch for
Thursday evening through Saturday evening for all of SE AZ.
Ensembles favored this feature tracking farther west and lifting
northward on Sunday with subsidence in the wake of it over SE AZ.
Thus, expect improving weather Sunday with limited shower and
thunderstorm coverage early next week. High temperatures will remain
near normal except on Friday through Sunday when below normal
readings will occur due to the anticipated rain and cloudiness.

&&

.AVIATION...Valid through 22/12Z.
SCT-BKN clouds at 8k-12k ft MSL much of the period. Widespread
SHRA/TSRA developing this afternoon and evening. Expect brief MVFR
CIGS/VSBYS and mountain obscurations around TSRA along with gusty
outflow winds, potentially in excess of 45 kts with the strongest
storms. Otherwise, SFC wind generally less than 12 kts following
diurnal trends. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Monsoon continues to be active into this weekend
with scattered to widespread showers and thunderstorms. In
particular, Thursday through Saturday look extremely active with
heavy rainfall and flooding issues anticipated. While in this
pattern, showers and storms will be possible at all hours of the day
and overnight. Storms will also be capable of producing very gusty
winds in excess of 35 mph and numerous lightning strikes. Daytime
temperatures will remain below normal. 20-foot winds will generally
be less than 15 mph when not influenced by thunderstorms. Daytime RH
mainly above 25 percent into next Monday, with very good overnight
recoveries.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
   Flash Flood Watch from Thursday evening through Saturday evening
   for AZZ501>515.
&&

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