930
FXUS65 KTWC 170945
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
245 AM MST Mon Jun 17 2024

.SYNOPSIS...Temperatures decrease a bit today and Tuesday before
heating up again by Thursday. Moisture may begin to increase late
next week which would bring the potential for high-based
thunderstorms late in the week into this weekend.

&&

.DISCUSSION...The sky was clear this morning across southern
Arizona per latest satellite imagery. Water vapor imagery this
morning showed an upper level trof moving through the PacNW which
will continue east today. This feature will bring afternoon
breezes this afternoon and elevated fire weather concerns which
is addresses in the fire weather section below. Highs today will
be cooler than this weekend, around 2 to 6 degrees with biggest
change being across western Pima county.

Tuesday: Upper level trofiness continues across the western CONUS
with highs at or slightly cooler than today or around mid-June
normals.

Wednesday: Upper level heights/low-level thickness values increase
for warmer highs temperatures, around 2 to 4 degrees warmer than
Tuesday. To our east a rather impressive tropical wave moves
inland across Texas and eastern Mexico.

Wednesday night/Thursday morning: Westward push of moisture into
New Mexico with above mentioned tropical wave will help fuel
thunderstorm activity across New Mexico with thunderstorm outflows
sending shallow surface moisture, with dewpoints into the 50s
across Graham/Greenlee/Cochise counties Thursday morning.

Thursday: With the increase in moisture, although at the surface
they will mix out, there is a slight chance, less than 20% for
high-based thunderstorms mainly near the AZ/NM border. Another
shallow moisture push west from thunderstorm outflows with surface
dewpoints in the 50s making as far west as Picacho to Sasabe line
Friday morning.

Friday: Westward push of moisture will bring a 10% chance from
western Pima county to a 50% chance near AZ/NM border of
showers/thunderstorms with a mix of wet/dry storms. Had to make
some slight adjustments down with respect to PoPs as the
initialized guidance from NBM was a bit too high, likely driven
by the wetter ensemble members from GEPS.

Thursday and Friday will also be hot with heat risk for areas
from Tucson west up in the major risk category. Per coordination
with WFO Phoenix held off on issuing any heat related products.
Something for later shifts consider.

This upcoming weekend: Chance of thunderstorms each day as
elevated moisture for June remains over the area. At this time,
high temperatures will be not as hot as Thu/Fri.

&&

.AVIATION...Valid through 18/12Z.
SKC. SFC wind less than 10 kts and variable in direction until
17/16Z and then again 18/04z. Btwn 17/16z and 18/04z, SFC wind
SWLY at 12-18 kts with gusts to 22-30 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...A few degrees of cooling early today and Tuesday.
High temperatures will then heat back up Thursday and Friday.
Through the middle of this week, expect min RH values of 4-9
percent in the lower elevations and 8-15 percent in the mountains,
along with overnight recoveries between 25-40 percent in most
locations. RH values then increase 5-10 percent the latter half of
the week. Surface winds increase today, with southwest winds of
15-20 mph and gusts to 30-35 mph. A few areas will be near
critical fire weather thresholds this afternoon, but at this time
we not expecting it to be widespread enough for a warning.
Elevated afternoon/early evening winds of 15-20 mph then continue
for much of this week with an uptick in speeds for the eastern
zones (Safford area) on Thursday and Friday. By the end of this
week, models show an increase in mid-level moisture, resulting in
a slight chance mainly dry thunderstorms to the east of Tucson
Thursday and and as far west as Tucson Friday and Saturday.

&&

.CLIMATE...The average daily dewpoints will be increasing across
southeast Arizona as the week progresses. Below is the forecast
average daily dewpoint values for Tucson over the next 7 days.

Today: 34F
Tuesday: 35F
Wednesday: 39F
Thursday: 44F
Friday: 55F
Saturday: 57F
Sunday: 58F

Confidence moderate in these values.

&&

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

&&

$$

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