124
FXUS65 KTWC 252157
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
257 PM MST Wed Mar 25 2026
.SYNOPSIS...Daily record high temperatures will continue through
Friday, as the historic March heat wave continues. Visitors and
people not typically accustomed to the heat are urged to take
precautions during the hottest hours of the day and to limit outdoor
activities. Moisture increases over the weekend, which will result
in a chance of showers and thunderstorms late Saturday into early
next week.
&&
.DISCUSSION...The heat continues through Friday with daily record
high temperatures in jeopardy before the arrival of a pattern change
for the upcoming weekend. Daytime heating will allow for typical
afternoon breeziness today and tomorrow afternoon. A few gusts to
around 20 mph at times, but overall little to no impacts will result
from wind of this magnitude.
Friday we will see the winds begin to ramp up as a backdoor cold
front squeezes air up and over the continental divide channeling an
easterly wind from New Mexico into our eastern valleys and along the
Interstate 10 corridor. Elevated wind speeds in the 15-25 mph range
(gusts around 30-35 mph) combined with very dry air out ahead of the
front will result in near critical fire weather conditions early
Friday afternoon across Graham, Greenlee, and eastern Cochise
county. The duration of near critical fire weather conditions will
be highly dependent on the timing of the front which will usher
relatively cooler and moist air into southeast Arizona.
A delayed arrival of front would result in a slower more gradual
increase in relative humidity with a few hours of near critical fire
weather conditions Friday afternoon whereas a faster arrival of the
front would result in an abrupt moisture increase with the arrival
of stronger winds. My hunch is that we will trend toward the slower
solution as the front gets held up on the divide in central New
Mexico for an hour or two. However, we could still start seeing
moisture spill over the divide into the San Simon Valley early
Friday afternoon with relative humidity jumping into the mid to
upper teens. Regardless of timing, the upper Gila River Valley near
and northwest of Safford will geographically have the best shot at
remaining drier a bit longer before the arrival of moisture.
By this weekend, additional mid-level moisture will be transported
into southern Arizona as the mean upper flow becomes more southerly.
Ensembles continue to depict precipitable water jumping up on Sunday
to around 225-300% above normal. We continue to advertise a slight
chance (10-20 percent) of showers or thunderstorms Saturday evening
with the uptick in moisture. That being said, with the atmosphere
still moistening up, we will mostly see cloud buildups initially
resulting in virga and perhaps (10-15%) a few thunderstorms
resulting in dry lightning. The better chance for any measurable
rain will come on Sunday (20-40%) lingering into Monday and Tuesday
(10-30%). With moisture, clouds, and perhaps some precipitation,
look for cooler high temperatures this weekend overall, but still
running above normal for late March.
&&
.AVIATION...Valid through 27/00Z.
Mostly SKC conditions with a FEW high level cirrus clouds AOA 20k ft
AGL thru the valid pd. SFC winds WLY/NWLY 8-14 kts with ocnl gusts
to 18-22 kts thru 26/03Z and again after 26/19Z. Between 26/03Z and
26/19Z, SFC winds terrain driven and less than 10 kts. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Strong high pressure aloft will continue to
result in high temperatures of 15-20 degrees above normal through
Friday. High temperatures will then lower over the weekend into
early next week, but will still be around 10 degrees above normal.
Very dry conditions will persist through Friday, with minimum RH
values at all elevations generally in the 5-10 percent range.
Moisture will move into southeast Arizona this weekend,
resulting in a 10-20 percent chance of showers and
thunderstorms Saturday evening mainly from Tucson east. Dry
lightning will be a possibility Saturday evening. Precipitation
chances increase Sunday into the 20- 40 percent range from Sells
eastward, with lingering chances (10-30 percent) for Monday and
Tuesday from Tucson eastward. Minimum RH values increase over
the weekend with values generally in the 15-25 percent range in
the lower elevations and up to 40 percent in the mountains.
20-foot winds will generally be 10-15 mph with some afternoon
gusts to 25 mph through Thursday. Winds then shift around to an
east/southeast direction across eastern areas Friday and all of
southeast Arizona Friday night into early Sunday. Wind speeds
will be around 20 mph (gusts to 35 mph) for eastern areas Friday
and 15-20 mph and gusts to 30-35 mph on Saturday. Near critical
fire weather conditions are expected Friday afternoon across
portions of Cochise, Graham and Greenlee counties.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DVS
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