558
FXUS65 KTWC 150927
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
227 AM MST Wed Jan 15 2025

.SYNOPSIS...A brief warm up is expected over the next couple of
days, peaking Thursday with daytime highs at about 3-7 degrees
above normal. Then a couple weather system move through bring a
slight chance of showers mainly northeast of Tucson Thursday Night
into Friday and again Sunday into early next week. Cooler
temperatures return starting Friday with more significant cooling
early next week.

&&

.DISCUSSION...Current temperatures are generally 2-6 degrees
warmer than this time last night. The threat for widespread
sub-freezing temperatures in the lower deserts is gone for the
the time being, although sub-freezing lows will still occur east
of Tucson. In the upper levels water vapor shows a couple weak
disturbances over northern Arizona and the southern Plains with a
closed low off the coast of Baja underneath a ridge. The
disturbance over Arizona will drift west becoming absorbed by the
closed low. By Thursday the closed low starts to move inland and
begins to open up. In between now and then heights will increase
over Arizona leading to a brief warm up today and Thursday. Highs
today will be around normal and 3-7 degrees above normal Thursday.
An easterly pressure gradient also sets up today leading to some
breeziness in locations prone to easterly winds such as the Gila
River Valley.

Moisture will be in short supply as the aforementioned low moves
inland. This will result in just 15-30 percent PoPs mainly north
of Tucson Thursday afternoon into the overnight hours. Any precip
that does fall will be very light with no impacts expected.
Friday looks to be dry as northwest flow dominates in the wake of
the trough. Winds will also be breezy Friday mainly from Tucson
eastward and temperatures cool to a few degrees below normal.

This weekend into early next week a longwave trough sets up over
most of the CONUS. Ensembles show a couple disturbances moving
around its southwest periphery this weekend into early next week.
The first passes through the Four Corners Saturday with the main
effects being keeping winds slightly elevated and reinforcing the
cooler air. The second disturbance looks to be a bit stronger than
the first and moves through sometime early next week. Ensemble
500mb height spreads show uncertainty with its westward extend and
the speed it moves through. This trough will be fairly dry with
current NBM PoPs 15-25 percent east of Tucson Monday. However
models are more confident in this second disturbance bringing
colder air in. Lower deserts including the Tucson could see low
temperatures in the mid to upper 20s Tuesday or Wednesday morning
next week.

&&

.AVIATION...Valid through 16/12Z.
Clear skies/SKC conditions thru 15/15Z, then SCT-BKN clouds AOA
20k ft thru the end of the forecast period. SFC wind NELY to SELY
thru the forecast period, generally less than 10 kts at most
locations. Stronger SELY wind at KTUS and KSAD between 15/15Z and
15/21Z, with wind speeds of 10-15 kts and gusts to 25 kts.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Dry conditions will prevail across much of southeast
Arizona the next 7 days, with a slight chance (15-30%) of light
precipitation to the east of Tucson Thursday night and early next
week (mainly in the mountains). East/southeast winds today and
Thursday with some gusts to around 25 mph during the morning hours
in locations exposed to easterly winds. Elevated west/northwest
winds are then expected on Friday, especially in Cochise and
Graham counties, with wind speeds of 15-20 mph and gusts to around
30 mph. 20-foot winds will be 15 mph or less Saturday and Sunday,
with increasing winds again to start next week. Min RH values
will be 12-20 percent in the valleys and 20-30 percent in the
mountains through early next week.

&&

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

$$

Hardin

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