Drought in Arizona, April 15 to 30, 2025

Area Forecast Discussion
National Weather Service Tucson AZ
306 AM MST Tue Apr 15 2025

.SYNOPSIS...

Unseasonably warm temperatures continue through tomorrow before a
cooling trend ends the week. Breezy to windy conditions are
expected each afternoon through most of the week. The strongest
winds are likely Thursday which will result in critical fire
weather conditions, along with the potential for patchy blowing
dust. Another, more established weather system moving into the
Desert Southwest late in the week into the weekend will provide
cooler afternoon temperatures and even a chance of light
precipitation.

&&

.DISCUSSION...

In the upper levels this morning, an eastern Pacific trough sits
off the California coast, while a southwest-northeast oriented
mid- level jet streak is extending from the base of the trough
through southeastern Arizona. Over the coming several days, this
trough will slowly shift east, putting southeastern Arizona under
increasingly active flow within a tightening pressure gradient.
Breezy to windy conditions will follow this trend, especially
Thursday as the mid-level jet intensifies over the region. With
dry air in place, multiple days of near critical to critical fire
weather conditions are expected. High temperatures will remain
well above average through tomorrow, then trend down starting
Thursday to below average Friday and Saturday.

Today and Wednesday will generally see similarly breezy southwest
winds of 10-20 mph, with gusts to 30 mph. The exception being
southern Cochise county on Wednesday where winds of 20-25 mph and
gusts to 35 mph are forecast. This wind increase will also likely
produce near critical fire weather conditions, if not periods of
critical conditions. Confidence wasn't high enough in duration for
a headline at this time, however this will need to be monitored.

Thursday will see the mid-level jet strengthen over southeastern
Arizona, both tightening a surface pressure gradient and
intensifying mid to lower level winds. Southwest winds will likely
increase into the 20-30 mph range, especially in areas near and
east of Tucson-Nogales. 40-45 mph wind gusts will be likely, with
wind gusts to 50 mph possible in areas of Graham and Cochise
counties. These winds will be capable of producing blowing dust in
normal dust-prone locations...and given the dry air in place,
critical fire weather conditions are also likely. A Fire Weather
Watch remains in effect and a headline for wind will likely be
needed as lead time decreases.

Friday into the weekend, the Pacific low is expected to open and
phase with a northern stream trough dropping in from the Great
Basin. Temperatures Friday drop to below normal with increased
winds and near critical fire weather conditions possible again.
The trough axis is expected to swing through on Saturday with a
chance of showers along the associated cold front. Greatest
coverage and probabilities for measurable rain generally lie
north of Tucson. Good model agreement exists in the cool air push,
with NBM probabilities showing likely chances for below normal
highs in the 70s across most desert locations. Depending on
coverage and duration of cloud cover, highs remaining in the 60s
are a distinct possibility. Low temperatures dropping well into
the 30s are likely Sunday morning in the Sulphur Springs Valley
(the chance of a near to sub- freezing morning low in the Willcox
area can't be ruled out). Temperatures quickly rebound by early
next week after the system exits.

&&

.AVIATION...Valid through 16/12Z.

Generally SKC through the TAF period with FEW-SCT shallow cumulus
at 10k feet this afternoon north and east of KTUS. Surface winds
becoming southwesterly 12-18 kts with gusts to 28 kts (especially
at KOLS-KDUG) after 15/16Z, then diminishing after 16/01Z.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...

Breezy to windy with near critical to critical fire weather
conditions through the work week. High temperatures will be well
above normal today and Wednesday then trend down Thursday through
Saturday. Near critical fire weather conditions expected today and
Wednesday with southwest winds of 15 to 20 mph across much of
southeastern Arizona. Periods of critical fire weather conditions
possible Wednesday afternoon in southern Cochise county where
stronger winds of 20-25 mph and gusts to 35 mph are forecast.
Minimum relative humidities range from 10-15 percent across desert
locations to 20-25 percent in the mountains today. Minimum RH
falls to 5 to 10 percent Wednesday. Stronger winds across the area
are expected Thursday with 20-30 mph winds and gusts up to 50 mph,
especially in eastern zones. With dry air still in place, critical
fire weather conditions are forecast and a Fire Weather Watch
remains in place. Though moisture begins to move in from the west
Friday, at least near critical fire weather conditions are
possible again in Cochise county. Cooler temperatures and a chance
for light precipitation arrives with a crossing system on
Saturday.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Thursday morning through Thursday
evening for AZZ151>154.

&&

Public...Edwards
Aviation...Edwards
Fire Weather....Edwards

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