276
FXUS65 KTWC 112055
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
155 PM MST Sat May 11 2024

.SYNOPSIS...Warm, dry, and breezy conditions continue through the weekend. Daily
high temperatures will be near normal through the weekend, then
several degrees above normal next week.

&&

.DISCUSSION...Satellite imagery shows an upper level low over
northern Arizona that has brought in the continuous westerly flow
across Southeast Arizona over the last several days. Luckily, the
low will be moving out of our hair very soon. But first, it will
bring gusty to breezy conditions rest of this afternoon and
keeping temperatures around the 80s to lower 90s. Near similar
conditions expected tomorrow as the low moves to our east, but
the winds will be more on the gusty side with pockets of locally
breezy.

Temperatures for the start of the week will be a near to slightly
above seasonal normal. The typical afternoon gusty winds returns
due to the differential heating of the May sun. By Wednesday, a
small upper level low, along with a larger trough draped along
the Great Basin, will be moving through the region to keep
temperatures in check and bringing low chances (~20%) for showers
and thunderstorms for the White Mountains.

Looking ahead in the last half of the week, ensemble model
consensus is not there yet on the type of pattern; ridge building
or troughiness. Let`s start with the troughiness camp solution,
~53% of the ensemble members lean on a troughy pattern along our
western edge which can be resulted from the upper level low
moving across the region in the middle this week. The low would
amplified the trough along the Great Basin and thus make it stick
around longer to bring some breeziness and temperatures in the
lower 90s. There is still variations in type of solution on how
breezy or even with the temperatures. In the other camp, ~47% of
members show a ridge building with different model interpretations
on how much building and where the ridge will be place. That
ridge will boost temperatures to the upper 90s and possibly in the
100 degree territory. (For reference, last year Tucson hit 100F
on April 30th and 30-year normal is May 18th). 21% of members
within the ridge building camp lean on the stronger ridge which
could result more for chances to hit the 100 degree mark. The
GEFs is the main hitter in that camp, but the chances for Tucson
hitting and exceeding 100 degrees on Saturday is 10% and Sunday
25%. Still, looking at both camps, the 25th-75th percentiles is
91F-98F for Saturday and 93F-100F for Sunday. That is a some
spread in the temperature solutions from all of the ensembles!
Therefore, there is lower confidence on the ridge building
solution and a lean of more confidence towards on some variation
of a troughiness pattern.

&&

.AVIATION...Valid through 13/00Z.
Skies SKC through the valid forecast period. SFC winds generally
westerly to northwesterly at 12-18 kts with gusts 25-30 kts
through 12/03Z and again after 12/18Z through the end of the
period. During the nighttime hours, SFC winds less than 10 kts
and following typical diurnal trends.Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Afternoon temperatures near to slightly above
normal will persist into next week. Min RH values will remain in
the single digits in the valleys, with values generally in the
teens for the mountains. Expect breezy west to northwest winds
15-20 mph this afternoon with gusts to 25-30 mph. These winds
combined with already low relative humidity in place may result in
brief near critical fire weather conditions. Otherwise, typical
afternoon breeziness will persist into next week each afternoon
due to daytime heating with winds becoming light and variable
overnight.

&&

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

$$

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