296
FXUS65 KPSR 182321
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
421 PM MST Tue Mar 18 2025

.UPDATE...Updated 00z Aviation Discussion...

&&

.SYNOPSIS...
Breezy to locally windy conditions will subside this evening, with
attention turning to the warming trend that will extend into next
week. Above normal temperatures expected to develop by late this
week, with well above normal to near record hot temperatures by
early to middle of next week.

&&

.DISCUSSION...
The cold front that moved across the region early this morning has
now exited east of Arizona this afternoon. Behind this front has
brought breezy to locally windy conditions across the majority of
the region, most notable in the higher terrain areas of south-
central Arizona, where gusts of 30-40 mph may be common. Here
locally in the Valley, 25-30 mph gusts, and locally higher, have
also occurred and will continue through the rest of the afternoon.
Heading into tonight, temperatures will continue to remain below
normal as winds subside and clear skies combine with the cooler
northwesterly flow aloft as the cold core of the troughing feature
remains overhead. The outlook for the rest of the week is
continued dry conditions under mostly clear skies with
temperatures warming more towards normal Thursday and above normal
by Friday.

Current satellite shows the low circulation associated with the
troughing extending into Arizona situated across the NM and CO
border as it slowly migrates eastward. This troughing feature will
eject east of the region by tomorrow, with some weak ridging
building across western CONUS through tomorrow. Warming
temperatures will result during this period, although the
magnitude of warming will remain modest due to a couple of
shortwaves moving across the Pacific Northwest and Intermountain
West on Wednesday and Friday. This will keep mid-level heights at
bay around 570-579 dam across Arizona under generally zonal flow
going through the end of the week.

Looking ahead through the weekend, the developing weather story is
strong ridging building across western CONUS behind the second
trough exits east of the Rockies by the early weekend. Ensembles
are in excellent agreement in this pattern evolution, even
extending through the middle of next week. This building ridge
will bring much hotter conditions, with prolonged and widespread
Minor HeatRisk Friday through the extended period. Minor HeatRisk
means people extremely sensitive to the heat should take the
proper precautions to protect themselves from the heat. The
magnitude of hotter temperatures is looking likely to reach the
middle-90s for lower desert locales, where probabilities of at
least highs above 90 degrees (95 degrees) are 80-100% (50-70%)
according to the latest probabilistic NBM output. Thus, out-of-
towners, snowbirds, and anyone expecting to spend long durations
outdoors should be cognizant of this prolonged heat coming next
week.

&&

.AVIATION...Updated at 2315Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation weather concerns are expected through the TAF
period. Winds through the evening hours will generally be out of
the west to northwest with some periodic gusts between 20-25 kts
persisting through sunset before sustained speeds diminish to
less than 10 kts through the rest of the TAF period. Wind
directions during the overnight period will become highly variable
before a more defined east to northeast directional component
materializes Wednesday morning. Wind directions by Wednesday
afternoon will switch out of the west to northwest. Mostly clear
skies will prevail throughout the period.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation weather concerns are expected through the TAF
period. At KIPL, west to northwest winds will prevail through
early Wednesday morning with speeds aob 5 kts before becoming very
light and variable the rest of the day. At KBLH, northwest to
north winds will prevail throughout the period with some elevated
gusts in the mid to upper teens persisting through the early
evening hours before sustained speeds diminish to aob 10 kts
afterwards. Clear skies will prevail throughout the period.

&&

.FIRE WEATHER...
A dry weather system will lead to widespread breezy to locally
windy conditions today. The strongest westerly to northwesterly
winds (gusts >35 mph) will be this morning in parts of Southeast
CA and Southwest AZ and this afternoon in Southern Gila County. In
both areas, RH magnitudes look to remain above the critical level
(15%) during the period of strongest winds. Still, there may be
some locally elevated fire weather conditions in Southern Gila
County this afternoon with some of the lower elevation spots
dipping below 20% RH. Lingering breeziness is anticipated
Wednesday morning through midday, with more of a northerly wind,
and there may be a slight uptick in winds Thursday, but after that
winds will be light and follow typical diurnal trends through the
rest of the week and weekend. Dry conditions will prevail through
the extended forecast, with daily MinRH values around 10-15%
after today. Temperatures will be coolest today, warm back to
seasonal levels by Thursday, and continue warming into the
weekend. Temperatures then shoot up further, into the 90s, next
week as strong high pressure develops.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

DISCUSSION...Young
AVIATION...Lojero
FIRE WEATHER...Benedict