979
FXUS65 KTWC 150917
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
217 AM MST Wed May 15 2024

.SYNOPSIS...Warm, mostly dry and locally breezy conditions will
persist into the weekend, with just a slight chance of showers and
thunderstorms in the White Mountains during the afternoon and early
evening hours today and Thursday. High temperatures will be right
around normal through Thursday, with highs warming to several
degrees above normal Friday through the weekend.

&&

.DISCUSSION...Very little change in the weather pattern or thinking
versus 24 hours ago. A weak upper level low currently moving into
the southern California coast will move east-northeast across
Arizona through Thursday, before shifting east of the region Friday.
This system will interact with mid level moisture in place over the
White Mountains and result in a slight chance of showers and
thunderstorms today and a chance of showers and thunderstorms on
Thursday. The thunderstorms will be mainly dry, with gusty/erratic
winds and lightning potentially causing new fire starts, but little
to no rainfall. This system will also result in elevated wind speeds
and near critical fire weather conditions today and Thursday to the
east of Tucson. Winds will be southwest-west today as the system
approaches from the west and then west-northwest on Thursday as the
system lifts northeast of the area. Wind speeds will be 15-20 mph
and gusts to near 30 mph over portions of Cochise, Graham and
Greenlee counties.

Shortwave ridging will then build in across the desert southwest
over the upcoming weekend. This will lead to dry conditions areawide
and warmer temperatures. High temperatures will top out 3-5 degrees
above normal on Friday, warming to 6-9 degrees above normal Saturday
and Sunday. The current/official forecast has 100 degrees for Tucson
on Saturday and 98 degrees on Sunday.

The ensembles/deterministic models show another weak system moving
across the area at the start of next week. This will result in
breezy to locally windy conditions and high temperatures lowering
back to near or slightly above normal readings.

&&

.AVIATION...Valid through 16/12Z.
FEW-SCT clouds at 8k-11k ft AGL, with some high level cirrus clouds
at times AOA 20k ft AGL thru the forecast period. A slight chance of
-SHRA/-TSRA northeast of KSAD in the White Mountains between 15/19Z
and 16/03Z. SFC wind less than 12 kts and variable in direction thru
15/18Z and again aft 16/04Z. SFC wind between 15/18Z and 16/04Z,
SWLY/WLY at 11-17 kts and gusts to 20-27 kts, with the strongest SFC
wind east of KTUS in the vicinity of KALK, KDUG and KSAD. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...High temperatures will be right around normal
through Thursday. Highs then warm to 3-5 degrees above normal Friday
and 6-9 degrees above normal Saturday and Sunday. Min RH values in
the valleys will be in the single digits to lower teens the next 7
days, with values in the mountains generally between 10-20 percent
(except on Thursday when they will be in the 15-30 percent range).
20-foot winds will follow typical diurnal wind trends through the
weekend, with afternoon and early evening gustiness due to strong
surface heating. The strongest 20-foot winds will be today and
Thursday, especially to the east of Tucson, with wind speeds of 15-
20 mph and gusts to near 30 mph. Southwest-west winds are expected
today and west-northwest winds on Thursday. There will be just
enough mid level moisture in place in the White Mountains for a
slight chance of afternoon/evening showers and thunderstorms today
and a chance of showers and thunderstorms on Thursday. Any storms
that do develop will be dry, with gusty/erratic winds and lightning,
but little to no measurable rainfall.

&&

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

&&

$$

Zell

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