Forecast Discussion

Forecast Discussion for TWC NWS Office
147
FXUS65 KTWC 090851
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
151 AM MST Fri May 9 2025

.SYNOPSIS...High temperatures will be 6-10 degrees above normal
today through Monday with Tucson possibly hitting 100 degrees
Sunday and Monday. Winds will be breezy out of the east Saturday,
then breezy out of the west Monday through Wednesday. Temperatures
cool to a few degrees below normal by mid next week.

&&

.DISCUSSION...High pressure continues to build over the region and
is expected to continue into the weekend. This ridge will lead to
temperatures 8 to 10 degrees above normal and a chance for areas
mainly Tucson westward to reach 100 degrees Sunday and Monday.
For Tucson, current probability of reaching 100 degrees on Sunday
is 62 percent and 25 percent on Monday.

At the same time an east to west pressure gradient sets up
tomorrow into Sunday thanks to a fairly strong surface high
pressure in the Great Plains. This will lead to easterly winds
each day with the strongest winds in the Gila River Valley. The
gradient will be strongest on Saturday, which is when the
strongest winds are expected. This will lead to elevated fire
weather conditions with some brief localized areas of Red Flag
conditions. Not expecting more widespread Red Flag conditions
because the timing of the strongest winds is in the morning when
RH values will be above 15 percent. By the time RH values drop in
the afternoon, winds will begin to weaken.

Towards the beginning of next week the ridge begins to flatten and
is followed by a fairly strong Pacific low that moves into the
Pacific Northwest then pushes southward into the Great Basin. This
system, though dry in our area, will bring strong gusty west
winds Monday through Wednesday with the strongest winds expected
on Tuesday. These strong winds, along with low RH, and dry fuels
could lead to more widespread Red Flag conditions Tuesday
afternoon from Tucson eastward. Temperatures will drop to normal
or a few degrees below normal Tuesday through the end of the work
week.

&&

.AVIATION...Valid through 10/12Z.
SKC until 09/17Z when FEW to SCT mid to low level clouds AOA
10-15k ft AGL develop across the area. These clouds will dissipate
becoming SKC by 10/08Z and for the remainder of the forecast
period. SFC winds early this morning will be fairly light 5-10 kts
and variable. SFC wind will increase to 10-15 kts from the east by
09/18Z then gradually weaken into the afternoon and evening hours
becoming light and variable overnight. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Temperature continues to warm and humidity
continues to drop into the weekend as high pressure builds. A
backdoor front will result in breezy southeast winds east of
Tucson as early as Friday, but especially Saturday. Widespread
critical fire weather conditions are not anticipated with this
feature, although localized/brief near critical conditions will be
possible Saturday across portions of southeast Arizona.

Otherwise, the warm conditions we will experience today into this
weekend will back off the first half of next week as a dry trough
moves into the region. This will result in strong and gusty winds
returning to the area Monday through Wednesday, with the
strongest winds/potential for more widespread critical fire
weather conditions impacting the region Tuesday.

&&

&&

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

$$

Public...Malarkey
Aviation...Aviation Forecaster
Fire Weather....Fire Weather Forecaster

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NWS TWC Office Area Forecast Discussion