971
FXUS65 KTWC 110853
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
153 AM MST Tue Jun 11 2024

.SYNOPSIS...Excessive heat today through Thursday as high
pressure results in very hot temperatures. Slight cooling Friday but
temperatures still a few degrees above normal. Temperatures then
nudge upward again this weekend into early next week. Generally dry
conditions through the forecast period with a slight chance of
thunderstorms in the eastern mountains late in the week.

&&

.DISCUSSION...The main weather impact this week will be hot
temperatures as an Excessive Heat Warning is in effect for lower
elevations of southeast Arizona today through Thursday. The large
scale pattern features a strong upper ridge that will be centered
near the AZ/NM border through Thursday with a mid/upper low to our
west off the northern Baja/southern California coast. Not much
change to the forecast for temperatures with highs in Tucson around
108 today, then 109 Wednesday and Thursday. Latest NBM shows a 22%
chance of 110 or greater Wednesday and 17% Thursday for Tucson.
Given the hot temperatures and strong deep layer mixing, expect some
afternoon gustiness each day.

Ensembles show the aforementioned mid/upper low ejecting eastward
into AZ on Friday. The combination of an uptick in mid level
moisture and lift ahead of the shortwave trough will result in some
cloud build-ups and the slight chance of mainly dry thunderstorm
primarily across the higher terrain of Graham/Greenlee Counties
late Thursday into Friday.

As the trough will drop heights/thickness values a bit on Friday
that will result in a few degrees of cooling. An increase in
afternoon breeziness is also expected especially east of Tucson.

For the weekend broad ridging builds back in with temperatures
nudging upward again. Some locales will be flirting with major heat
risk again so will need to keep an eye on temperature trends over
the next few days in the case for additional heat headlines.

&&

.AVIATION...Valid through 12/12Z.
SKC-SCT clouds AOA 20k ft AGL thru 11/18Z and clear skies aft 11/18Z
thru the remainder of the forecast period. SFC wind generally less
than 12 kts thru this forecast cycle, favoring a WLY/NWLY direction
during the afternoon/early evening hours and variable in direction
at other times. Some afternoon gusts to around 20 kts. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Hot temperatures this week, with high
temperatures 7-10 degrees above normal through Thursday and then 3-6
degrees above normal Friday through the weekend. Limited mid level
moisture will result in a slight chance of mainly dry thunderstorms
mainly in the higher terrain northeast of Tucson late Thursday and
Friday. These storms may produce gusty and erratic winds, along with
lightning. Expect min RH values of 3-9 percent in the lower
elevations and 7-15 percent in the mountains through this weekend,
along with poor overnight recoveries between 20-35 percent in most
locations. Outside of any thunderstorm outflows, 20-foot winds will
follow typical diurnal patterns, with afternoon/early evening
gustiness due to strong surface heating. Sustained 20-foot wind
speeds will generally be 15 mph or less through Wednesday, with
elevated winds at 15-20 mph and gusts to around 30 mph to the
east/southeast of Tucson Thursday through the weekend. The strongest
20-foot winds continue to be on Friday, with wind speeds near or at
critical levels to the east of Tucson.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning from 11 AM Tuesday to 8 PM MST Thursday
for AZZ501>509.

&&

$$



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