348
FXUS65 KTWC 092123
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
223 PM MST Sun Mar 9 2025

.SYNOPSIS...A warming trend is expected today through Monday,
before active weather returns with systems crossing southern
Arizona Tuesday into Wednesday, and again Thursday into Friday.
Breezy conditions with a chance of desert rain and mountain snow
will arrive with the system on Tuesday and then greater chances
for precipitation come with the following system on Thursday.

&&

.DISCUSSION...High pressure has moved into the desert Southwest
and will remain through tomorrow. Over the Pacific a trough is
centered around 130W and will be making its way east over the next
couple of days. This will be the first of a couple troughs that
will impact the region this week. Temperatures today will be right
around normal warming to 4-8 degrees above normal Monday. Tucson
will likely see highs reaching 80 degrees.

The Pacific low moves onshore into southern California Tuesday,
begins to open up, then moves through northern Sonora/southern
Arizona overnight Tuesday. This is a little further south than
model runs from 24 hours ago. Initially this system will bring
strong gusty winds Tuesday afternoon especially along the
international border before rain chances start later in the day.
Isolated critical fire weather conditions will be possible south
and east of Tucson until moisture moves in by late afternoon.
Precip chances begin west of Tucson Tuesday afternoon, expanding
east over night Tuesday, then decreasing from west to east
Wednesday morning. Rain totals will generally be under 0.2" with
the bulk of the rain falling during the overnight hours. Thanks to
its more southerly trajectory over the Pacific this will be a
warm system with snow levels generally above 7000 feet. Snow
totals are expected to be 1"-3".

In the wake of the low Wednesday brief shortwave ridging will be
in place as a stronger low moves south out of the Gulf of Alaska.
Thursday models place it in southern California where it will help
bring another round of strong gusty winds to southeast Arizona.
Winds look to be stronger than Tuesday with wind advisory
headlines possibly needed as Thursday gets closer. Moisture will
still be in place so no fire weather concerns. Precip chances
begin Thursday afternoon and continue into Friday mainly east of
Tucson. Ensembles are fairly consistent with the trajectory of the
low, which takes the core through south-central Arizona overnight
Thursday. Because of its trajectory and strength this system is
expected to be wetter than the Tuesday system. QPF is generally
0.25"-0.75" with the bulk of that falling late Thursday afternoon
into the late evening. The low also brings a colder air mass with
snow levels around 5000 feet, possibly dropping to eastern valley
floors Friday morning. Current snow totals above 6000 feet are
generally 5"-10". High temperatures Thursday cool to 4-8 degrees
below normal and drop further Friday to 14-18 degree below normal.
Winds also remain breezy east of Tucson Friday.

&&

.AVIATION...11/00Z.
SKC expected through the TAF period. Winds become easterly late
this morning and increase to 10-15 kts with gusts to 20 kts this
afternoon. Winds decrease somewhat after 10/00Z but remain
easterly 5-10 kts into Monday morning.

&&

.FIRE WEATHER...A brief warming trend with drying conditions can
be expected today and Monday. Temperatures will be near normal
today and rise to 5-8 degrees above normal on Monday. Minimum
relative humidities falling below 10 percent across desert
locations and to 10-15 percent in mountain areas on Monday with
this warming trend. The first of two weather systems to move
across southern Arizona this week will arrive Tuesday. 15-25 mph
southwest winds with gusts up to 35 mph are likely ahead of the
first system on Tuesday, then valley rain and mountain snow will
begin to cross the region Tuesday afternoon and evening before
exiting Wednesday morning. Localized critical fire weather
conditions are possible with the windy conditions Tuesday
afternoon in areas south and east of Tucson until moisture moves
in from the west. The second system is expected to arrive
Thursday, bringing another round of increased wind and then
widespread chances for rain and mountain snow.

&&

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

$$

Hardin

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