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000
FXUS65 KTWC 092050
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
150 PM MST Tue Apr 9 2024

.SYNOPSIS...A weak weather system aloft will result in a slight
chance of very-light showers for portions Southeast Arizona
today. This will allow temperatures to remain below normal for
one more day before a strong warming trend is expected for the
second half of this week. This warming trend will likely result in
Tucson seeing its first 90 degree temperature of the year.

&&

.DISCUSSION...A low pressure system is moving easterly out of the
Southwest region which is currently bringing very light showers to
mainly virga in the White Mountains. There were a few rumbles here
and there due to low unstable conditions. The showers and/or virga
will slowly move southerly towards the I-10 corridor near Willcox
area and clearing out by the evening.

Wednesday through Friday, the 500mb ridge will build over the
region to bring warmer temperatures. Thursday will be one of the
warmest days for the period with Tucson west having over 75%
chance of 90 degrees or higher. It is indeed a switch from cooler
temperatures over last weekend to jumping up into the 90s. This is
a good time to review heat mitigation tips and general outdoor
safety.

The next pattern change will occur this weekend to bring breezy
conditions and mainly dry. A trough will be developing along the
California coast by Friday which will start to dig southwesterly
through the rest of the weekend. The breezy southerly conditions
on Friday ahead of the system. And, this system will be mainly dry
as the upper level moisture values are fairly low with PWAT values
of 0.1-0.3 inches. Temperatures will trend back into the mid- to-
lower 80s for the western deserts and mid 70s for the eastern
areas. So, dry, windy, and warm for the weekend.

&&

.AVIATION...Valid through 11/00Z.
SKC across a majority of SE Arizona for this forecast period. FEW-
SCT clouds AOA 15-20k ft will develop across the White Mountains
into KSAD but will begin to dissipate around 10/02Z and become SKC
by 10/04Z. SFC winds will be around 5-10 kts from the northwest with
gusts up to 25 kts in the afternoon hours becoming light and
variable overnight. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...A weather system will bring slight chance of very-
light showers in Graham and Greenlee Counties through the rest of
Tuesday afternoon. Minimum relative humidity values mostly 10-20
percent through rest of the today then drop to under 10 percent
for the lower valleys Wednesday into Friday. High temperatures
remain below normal today before warming up to above normal
readings Wednesday through Friday, with Thursday the warmest of
the three days. Gusty to breezy winds return Friday into the
weekend as another system moves through. Localized areas could see
brief critical to near critical fire weather conditions on
Friday, but fire danger and ERCs are still low for this time of
year.

&&

.CLIMATE...First 90 degree high date information for Tucson
Historical period (1895-2023): April 8th
Climatological normal period (1991-2020): March 30th
2023 1st date: April 10th

&&

&&

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

$$

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