276
FXUS65 KTWC 230953
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
253 AM MST Fri May 23 2025
.SYNOPSIS...Hot, dry and breezy across Southeast Arizona today,
with a slight cooling trend into this weekend. Afternoon high
temperatures will be near to slightly above normal through next
week.
&&
.DISCUSSION...Warm, dry and occasionally breezy conditions will be
the mainstay across Southeast Arizona over the next week. This
weather makes me think of an old, lazy dog lying on the porch,
resistant to activity except lifting its head from time-to-time
to acknowledge a bird flying-by. The overall pattern this morning
is defined by a broad ridge of high pressure extending from the
Desert Southwest into Texas, with a dry trough of low pressure
moving into the West Coast. The southern portion of the trough
will close off across central California today, then slowly drift
east across the Great Basin through Sunday. This approaching
feature will tighten pressure gradients across Southeast Arizona
the next few days, resulting in some afternoon breeziness. Winds
will generally be southwest 15-20 mph with occasional gusts to
30-35 mph due to strong surface heating. Although wind speeds
should stay below critical fire weather thresholds today, brief
near critical thresholds will be possible during the afternoon...
especially those areas exposed to a southwest wind.
Split-flow in the Eastern Pacific the first half of next week
will allow for another dry upper-low to develop off the coast of
Southern California and Northern Baja by Wednesday, with little
movement into next weekend. This feature will allow for a
shortwave ridge axis to develop across the Southern Rockies/New
Mexico the second half of next week. A ridge in this location will
result in a south to southeast mid-level flow tapping into
moisture across SW Texas and NE Mexico. The numerical models have
backed off from their previous runs on the western extent of this
mid-level moisture nudging into the eastern portions of the CWA.
However, depending on the location of the upper low near SRN CA,
it may draw the moisture into the far eastern portions of our
neck of the woods late next week. The combination of this moisture
and the dry sub-cloud layer may result in dry elevated thunderstorms
with the potential for gusty and erratic outflows near the evaporating
downdrafts, especially Friday.
Otherwise, models have been consistent over the past few days with
regards to a weak tropical system developing along the southern
coast of Mexico and moving NW near the the tip of the Baja next
weekend. I am not concerned with this feature, but there may be
an increase in moisture up the Gulf of California/Sonora Mexico
which could potentially get wrapped up into the upper-low near SRN
California and impact Southeast Arizona with a chance of storms
around the first few days of June. At this point, a lot of things
would have to work out. So, I guess we are just like that old,
lazy dog...lifting its head in curiosity to look at that strange
looking bird hopping around in the yard.
&&
.AVIATION...Valid through 24/12Z. SCT-BKN high clouds AOA 20k ft
AGL thru the valid period. SFC winds terrain driven less than 10 kts
through 23/17Z, then SWLY/WLY 12-18 kts with gusts up to 30 kts
during the afternoon and early evening hours...becoming light and
terrain driven less than 10 kts overnight. Aviation discussion
not updated for TAF amendments.
&&
.FIRE WEATHER...Hot, dry and breezy today across Southeast
Arizona. Expect gusty southwest winds 15-20 mph with gusts to
30-35 mph this afternoon with minimum RH values around 5 percent.
Although wind speeds should stay below critical fire weather
thresholds, brief near critical thresholds will be possible
during the afternoon in those areas exposed to a southwest wind.
Breezy conditions will persist into the weekend. Single digit min
RH values at all elevations will persist over the next week, with
poor overnight recoveries.
Although confidence is low at this time, there is the potential
for some mid-level moisture to move into far eastern areas (along
the Arizona and New mexico state line) by the end of next week.
This may lead to some afternoon buildups and/or isolated dry
lightning strikes Thursday and Friday next week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
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