933
FXUS65 KTWC 160930
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
230 AM MST Sun Jun 16 2024

.SYNOPSIS...Hot today with an Excessive Heat warning in effect
for portions of southeast Arizona. Temperatures decrease a bit
early in the week before likely heating up again by Thursday.
Moisture may begin to increase late next week which would bring
the potential for high-based thunderstorms.

&&

.DISCUSSION...The sky was clear this morning across the desert
southwest. Hot day with highs similar or slightly hotter than
Saturday. Excessive Heat Warning remains in effect today for
parts of Pima, Pinal and Graham counties.

Monday: Slightly cooler with afternoon breezes as a trough moves
thru WA/OR into ID/NV. Elevated fire weather concerns in the
afternoon, mainly east of Tucson which is addressed in the Fire
Weather section below.

Tuesday: Coolest day of the week with highs at or up to 5 degrees
cooler than mid-June normals with wrn Pima county seeing the
biggest difference from climo.

Wednesday: Hotter as upper high builds in from the east.

Thursday and Friday: Hottest days of the upcoming week with
increasing heat risk. However, latest NBM guidance is not as hot
as previous runs and thats due to increasing moisture from the
east which initially moves into the eastern zones Thursday, with
surface dewpoints into the lower 50s thanks to thunderstorm
outflows in New Mexico pushing low-level moisture west. Another
low-level push of moisture again on Friday, possibly as far west
as Tucson. What is not certain is how far west the potential for
high-based thunderstorms will be on Friday. NBM may be a bit
aggressive in the western extent of thunderstorms chances Friday
especially when looking at the individual GEFS/EPS members.

Saturday: At this time NBM has the chance of showers and
thunderstorms ranging from a 10% chance western areas to 50%
chance eastern areas. What happens Thu/Fri will determine Sat.
Confidence low.

&&

.AVIATION...Valid through 17/12Z.
SKC. SFC winds less than 10 kts and vrbl in direction until 16/18z
and then again after 17/04z. Btwn 16/18z and 17/04z, SFC winds
SWLY/WLY at 11-16 kts with gusts of 18-25 kts. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Hot and dry conditions will today with a few
degrees of cooling early Monday and Tuesday. High temperatures
will then heat back up late in the week, with the hottest
temperatures of 2024 possible on 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. Sustained
20-foot wind speeds today will be 15 mph or less. Winds then
increase on Monday, with southwest winds of 15-20 mph and gusts to
30-35 mph. A few areas will be near critical fire weather
thresholds Monday, especially to the east/southeast of Tucson, but
at this time we not expecting it to be widespread enough for a
watch or warning. Elevated afternoon/early evening winds of 15-20
mph then continue for much of this week. 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 later this week. Below is the forecast daily
averages for Tucson from Tuesday through Saturday.

Tuesday: 34F
Wednesday: 38F
Thursday: 43F
Friday: 52F
Saturday: 53F

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Excessive Heat Warning until 8 PM MST this evening for
  AZZ504>506-509.

&&

#2709

$$

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