517
FXUS65 KTWC 130815
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
115 AM MST Fri Mar 13 2026
.SYNOPSIS...High pressure along the West Coast will result in warm
afternoon temperatures 10 to 15 degrees above normal through this
weekend. More significant heat (20 to 25+ degrees above normal)
is expected the second half of next week as high pressure across
the Desert Southwest is forecast to strengthen.
&&
.DISCUSSION...The succinct forecast for Southeast Arizona over
the next week is; warm then hot. This is due to the influence of a
mean upper-level ridge of high pressure in the Eastern Pacific and
West Coast. In the near term, our warm temperatures into this
weekend are the result of an anomalously strong ridge of high
pressure positioned along the California and Baja coastline. A
low-amplitude trough north of the Pacific Northwest will dive SSE
along the eastern periphery of the mean upper ridge the next few
days, temporarily flattening the ridge across the Desert
Southwest. This dry trough won`t be strong enough to lower
afternoon high temperatures by anything more than a few degrees.
It will, however, result in some breezes to the east and
northeast of Tucson Saturday and especially Sunday. The
combination of these sustained 20-foot winds 15-20 mph with gusts
to 25-30 mph and minimum RHs in the single digits to teens this
weekend will result in some very brief near critical fire weather
conditions both Saturday and Sunday, but are not expected to be
widespread or long-lived enough to be impactful.
Otherwise, a secondary high center building off the California coast
near 33N/130W Sunday is forecast to strengthen next week as the upper
flow amplifies and moves east into the LA basin next Tuesday...then
into SW Arizona next Friday. This high center is expected to be
very strong for this time of year, resulting in the potential for
moderate/major HeatRisk across Southeast Arizona the end of next
week into next weekend. The 13/05Z NBM 4.3 probability for the
Tucson International Airport (KTUS) to hit 100 degrees is 42% next
Thursday then up to 80-85% next Friday and Saturday. Given the
persistence in this solution over the past several days amongst the
majority of ensemble members, confidence is strong this heat will
eventually impact us next week and will eventually necessitate
heat-related headlines.
Reiterating the previous forecast discussion...we are on track
for afternoon temperatures 20 to 25 degrees above normal in spots
by late next week. This will result in widespread daily and March
monthly temperatures records. While this level of heat is more
typical of June, we have many visitors, seasonal residents and
outdoor events in our region this time of year which typically
aren`t exposed to are acclimated to such hot temperatures. The
time to prepare for the heat is now with heat safety precautions
kept top of mind as we head into this heat wave.
&&
.AVIATION...Valid through 14/12Z. SKC through 14/00Z this afternoon,
then SCT-BKN cirrus clouds AOA 20k ft AGL spreading from west to
east across Southeast Arizona. SFC winds SELY less than 10 kts thru
14/20Z, WLY/NWLY winds 10-14 kts with occasional gusts to 20 kts
through 14/03Z Friday evening, then relaxing to light and variable
less than 10 kts overnight. Aviation discussion not updated for
TAF amendments.
&&
.FIRE WEATHER...High pressure along the West Coast will result in
warm afternoon temperatures 10 to 15 degrees above normal through
this weekend. More significant heat (20 to 25+ degrees above
normal) is expected the second half of next week as high pressure
across the Desert Southwest is forecast to strengthen. West to
northwest 20-foot winds around 10 mph with occasional gusts to 20
mph this afternoon. Winds will become slightly stronger this
weekend with west to northwest 20-foot winds 15 to 20 mph with
gusts to 25-30 mph across Graham, Greenlee and Cochise counties.
Minimum RHs 8-18 percent areawide Friday through the middle of
next week, then lowering into the single digits late next week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
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