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700
FXUS65 KTWC 020942
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
242 AM MST Thu May 2 2024

.SYNOPSIS...
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Sunny, warm, and dry this week with breezy afternoons on
most days. A dry weather system will bring stronger breezes on
Sunday.
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&&

.DISCUSSION...
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In the short term, the pattern will be mostly
westerly flow to keep temperatures in the upper 80s to lower 90s
with typical afternoon breezes from surface heating and terrain
interaction. These conditions will continue through Saturday.

The change of weather will be from weather system moving through
region later in the weekend. The ensemble models have been
consistent on the timing of the trough coming from the Northwest
Pacific coast which is projected to pass over Southeast Arizona on
Sunday. The ensembles have been getting a better agreement on the
placement of the trough. The 500mb low pressure center will
generally over Nevada by Sunday morning and this will create a
tighter pressure gradient over Southeast Arizona. Even, the GFS
700mb wind field will have 30 to 40 knots and likely giving a
little more lean in the NBM guidance. The latest NBM has a 45
percent of exceeding 35 mph or higher for majority of the region
with stronger gusts in the exposed areas and in higher
elevations. Temperatures will stay up in the upper 80s to lower
90s with the minimum relative humidity in the single digits for
the valleys and in the upper teens to lower twenties in the
mountains. With that, the warm temperatures and the low
humidities are more of a slam dunk in confidence levels, whereas
the wind confidence has started to grow a little more since the
last forecast package. The trifecta of the warm temperatures, low
humidities, and the wind can lead to near critical to critical
fire weather concerns on Sunday afternoon. Stay tune for the
updates on the wind speeds and gusts as we get closer to Sunday.

After Sunday, high temperatures will drop 3 to 5 degrees on
Monday and then return to the same tune as before, the upper 80s
to lower 90s with the typical afternoon breezes for the most of
the new week. A few ensembles hint at another similar pattern
change later in the week.
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&&

.AVIATION...
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Valid through 03/12Z.
SKC throughout the forecast period. SFC winds this morning are
light and variable through 02/20Z and returning again after
03/02Z. During daylight hours, winds will generally be
southwesterly to westerly at 10 to 15 knots with the occasional
gust of 20 knots in the late afternoon. Wind speeds less than 15
kts. Aviation discussion not updated for TAF amendments.
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&&

.FIRE WEATHER...
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High temperatures remain above normal throughout the
rest of the week. 20-ft winds will generally be less than 15 mph
through Saturday. Min RHs in the valleys continue to be in the
single digits to the low teens for the lower valleys with values
in the teens to the lower twenties for the mountains. A dry weather
system will be passing on Sunday to bring dry and breezy to
locally windy conditions in the afternoon. The dry, windy, and
warm conditions will put areas Sells eastward near critical to
critical fire weather concerns on Sunday afternoon. After Sunday
and through the new week, winds will return to the typical
afternoon breezes of 10 to 15 mph.
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&&

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

$$

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