440
FXUS65 KTWC 100912
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
212 AM MST Tue Mar 10 2026
.SYNOPSIS...A weather system tracking across the region will bring
scattered showers and thunderstorms along with high elevation
mountain snow through this afternoon across Southeast Arizona.
Afternoon high temperatures are expected to be below normal today
but will quickly rise to 10 to 15 degrees above normal by the end
of the week.
&&
.DISCUSSION...The upper pattern this morning is mainly defined by
a strong closed upper-low centered near the Baja Spur this
morning. Although this feature has been rather stagnant the past
6 to 12 hours, satellite imagery indicates that the stronger flow
has rounded the base early this morning, and should assist in
ejecting this system across northern Sonora Mexico thru 10/18Z
late this morning, and into New Mexico by 11/00Z this afternoon.
Given the slow motion of the upper-low this morning, we continue
to see bands of scattered showers with embedded thunderstorms move
north across the eastern half of our forecast area (mainly from
Tucson east). Although the best dynamics/lift with this system
will generally be across Sonora Mexico, we will see portions of
Cochise/Graham and Greenlee counties clipped as the feature ejects
NE thru the morning. I anticipate the coverage and intensity of
showers will increase across the aforementioned areas between
daybreak and 10 am MST, with between 0.33-0.50 inches of rainfall
in the valleys, and 0.66-0.75 inches of water equivalent
precipitation in the higher terrain. Snow levels remain between
7500-8000 feet this morning, so snowfall amounts between 2-4
inches of snowfall are possible in the highest elevations,
generally above 8000 feet.
In the wake of the departing upper-low, we will see a strong
amplified upper ridge of high pressure develop over the Eastern
Pacific/West Coast this week. The eastward progression of the
ridge axis will result in a significant warmup both Wednesday and
Thursday, with approximately 10 degrees of warming each day. This
will bring afternoon temperatures across Southeast Arizona from 5
to 10 degrees below normal today, to 10 to 15 degrees above normal
by the end of the week. The 10/05Z NBM probability for the Tucson
International Airport (KTUS) to meet or exceed 90 degrees this
Friday/Saturday and Sunday is 45-55 percent each day...bumping up
to 82 percent on Monday of next week. At this time, there is
strong agreement amongst the GEFS and ECMWF ensemble members on
developing a very strong ridge across Arizona the middle of next
week. This translates to the possibility for very hot temperatures
for the month of March (nudging up to the monthly record high
temperatures). The way too early 10/05Z NBM probability for
meeting or exceeding 100 degrees at KTUS next Wednesday/Thursday
and Friday is 50-65 percent. To put things into proper
perspective, the earliest 100 degree day at KTUS is April 11th,
set last year in 2025. Zoiks.
&&
.AVIATION...Valid through 11/12Z. SCT-BKN clouds 5-9k ft AGL with
scattered -SHRA and isolated -TSRA with storm coverage gradually
diminishing from west to east between 10/18Z and 11/00Z this
afternoon. Skies clearing this evening through the end of the
valid period. SFC winds less than 10 kts thru 10/18Z, then WLY/NWLY
10-15 kts with some higher gusts...especially near KSAD this
afternoon. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A weather system tracking across the region will
bring scattered showers and thunderstorms, along with high
elevation mountain snow through this afternoon across Southeast
Arizona. Although afternoon high temperatures are expected to be
below normal today, they will quickly rise to 10 to 15 degrees
above normal by the end of the week. Heads up: There is a potential
for hot temperatures near the century mark by the middle to end
of next week across the lower deserts of Southeast Arizona.
West to northwest winds 10 to 15 mph today with some higher gusts
across Graham and Greenlee counties. Otherwise, normal diurnally
driven winds less than 15 mph will return to the area Wednesday
through this weekend.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
NWS Tucson (TWC) Office
Tucson, AZ 
