393
FXUS65 KTWC 182114
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
214 PM MST Sat May 18 2024

.SYNOPSIS...Dry with higher temperatures this weekend. A weak
trough will bring temperatures down to near-normal early next
week with breezy afternoon winds.

&&

.DISCUSSION...All eyes are on the thermometer today, with the
potential for Tucson to possibly reach 100 degrees today. As of
2 pm MST, the highest temperature has been 97 degrees. This is
due to the shortwave ridge that is keeping the area 5-8 degrees
above normal.

An upper level trough then begins to move down the west coast
into the region tomorrow, tightening the gradient Monday as the
system comes in. With this gradient, the winds increase more than
our typical afternoon breeziness to 10-20 mph with gusts 30-35 mph
during this time, with the strongest winds with this system
remain to areas east of Tucson. This elevated wind led to the
issuance for a Fire Weather Watch for Monday afternoon, see more
in the fire weather discussion below. This system continues to be
mainly dry with some chances for some high based storms that would
have an uphill battle having any precipitation making its way to
the valley floor with the very dry low and mid levels.

After this system passes, the pattern becomes more zonal with a
few shortwave troughs picking up the afternoon winds slightly.
This pattern will keep the temperatures at or near normal for the
rest of the forecast period.

&&

.AVIATION...Valid through 20/00Z.
FEW-SCT clouds AOA 20k ft AGL primarily between thorough 18/21Z.
From KTUS east, FEW Cumulus around 8-10k ft AGL between 18/20Z and
19/03Z. SFC Wly/SWly winds at 10-17kts though 19/06Z then again
19/20Z through the end of the period. Otherwise SFC winds remain
under 10kts and follow diurnal trends.

&&

.FIRE WEATHER...Dry conditions continue this weekend with
min RHs in the single digits for the lower valleys and the teens for
the higher terrain. Temperatures this weekend approach the high 90s
for much of the valleys, with today being the hottest day, before
dropping to near normal by Tuesday. Westerly 20-foot winds will
generally follow diurnal trends through the beginning of next week
with gusty afternoon winds (less than 30 mph). However, Monday
and Tuesday will have the strongest 20-foot winds due to a passing
system to our north (wind gusts up to 35 mph). In addition, there
is potential for isolated dry thunderstorms Monday. With the low
RHs, higher winds, and the dry fuels a Fire Weather Watch has been
issued for Monday morning through Monday evening.


&&

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

$$

Tetrault

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