202
FXUS65 KTWC 042045
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
145 PM MST Sat May 4 2024

.SYNOPSIS...Sunny, warm and dry through the weekend. A dry
weather system will bring windy conditions on Sunday, along with the
possibility of some blowing dust. Cooler Monday, then temperatures
warm up the remainder of next week with continued afternoon breezes.

&&

.DISCUSSION...A Pacific storm system off the southern Oregon coast
will move southeast into the Great Basin on Sunday and then east
into the plains on Monday. This system will bring breezy to windy
conditions across southeast Arizona on Sunday. Expect southwest
winds of 15-30 mph and gusts to 35-45 mph from late Sunday morning
through Sunday evening. Wind speeds will be just below wind advisory
criteria, so no wind headlines for Sunday. However, wind speeds will
exceed critical fire weather thresholds, so have elected to upgrade
the Fire Weather Watch to a Red Flag Warning. The Red Flag Warning
will be in effect from 11 am MST through 7 pm MST Sunday. I could
have gotten a little fancy with the Red Flag Warning and left out
far western Pima County (most likely just below criteria), but this
would split up Fire Weather Zone 150 with 2/3`s of the zone still in
the warning, and therefore, elected against this approach. The same
could have been said for elevations above 7.5k feet, where fuels may
not quite be as available to burn. At the end of the day, with the
wind speeds involved, if a fire start does occur it will spread
rapidly and be difficult to control. Blowing dust will also be
concern on Sunday, especially in the favored areas along I-10
between Willcox and San Simon and from Red Rock northward.

On the back side of the system Monday, high temperatures will lower
5-7 degrees (versus highs Sunday) and top out 2-4 degrees below
normal. Still breezy, but below wind advisory/fire weather
thresholds. Expect west winds of 15-20 mph and gusts to around 30
mph across portions of Cochise, Graham and Greenlee counties and
lower wind speeds further west.

Tuesday and Wednesday, high temperatures warm back up to 1-3 degrees
above normal. Wind speeds pick back up during the afternoon and
early evening hours, especially to the east of Tucson. Cochise,
Graham and Greenlee counties will be near critical fire weather
thresholds. Something to keep an eye on going forward.

Thursday and Friday, highs continue to be 1-3 degrees above normal,
with typical May afternoon breezy conditions due to strong surface
heating.

&&

.AVIATION...Valid through 06/00Z.
Clear skies/SKC conditions thru much of the forecast cycle, with
just a FEW clouds AOA 20k ft AGL at times. SFC wind SWLY/WLY at 10-
16 kts and gusts up to 24 kts thru 05/02Z, with the strongest SFC
wind east of KTUS in the vicinity of KDUG and KALK. SFC wind less
than 12 kts and variable in direction between 05/02Z and 05/15Z.
Increasing SFC wind after 05/15Z, with SWLY SFC wind at 17-25 kts
and gusts up to 40 kts between 05/18Z and 06/00Z. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...High temperatures will be 2-5 degrees above normal
through Sunday and then within a couple of degrees of normal next
week. 20-ft winds will generally be 10-20 mph today. A dry weather
system will move to our north on Sunday, resulting in windy
southwest winds of 15-30 mph and gusts between 35-45 mph across most
of southeast Arizona. Breezy winds during the afternoon and early
evening hours then persist much of next week, especially to the east
of Tucson. Min RHs values in the valleys will be in the single
digits to lower teens, with values generally in the teens for the
mountains.

On Sunday, the combination of strong and gusty southwest winds, low
relative humidity levels and a high fire danger rating will result
in critical fire weather conditions from the late morning through
early evening hours for most of southeast Arizona. A Red Flag
Warning has been issued for all of southeast Arizona from 11 am to 7
pm MST Sunday.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 am to 7 pm MST Sunday for AZZ150>154.

&&

$$

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