South West Weather

403
FXUS65 KPSR 301137
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
437 AM MST Thu Apr 30 2026

.UPDATE...Updated 12z Aviation Discussion...

&&

.KEY MESSAGES...

- Near normal temperatures through mid week will turn hotter going
  into the weekend with lower desert highs into the nineties as
  early as Friday.

- A trough approaching the West Coast will tighten the pressure
  gradient across the Desert Southwest. Expect widespread breezy
  to windy conditions Saturday and Sunday.

- The combination of low afternoon relative humidities and gusty
  winds will likely lead to elevated fire weather concerns this
  weekend.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
Current objective analysis show the center of the closed low now to
the region`s SW, off the western coast of Baja Peninsula. This
system continues to track more to our south, across northern Mexico,
resulting in rainfall chances to be mostly confined to southeastern
Arizona. Mid to upper level moisture will increase with the passing
of this system, however, any activity in our CWA will be limited to
mostly virga with slightly higher probabilities (5-10%) over the
higher terrain of Gila County. Even though most of the activity is
expected to be to the region`s SE, the HRRR and NAM models show
strong outflows reaching south-central Arizona by this evening, and
could last up to midnight tonight. This can lead to wind gusts up to
35 mph and areas of patchy blowing dust.

Otherwise temperatures today will be in the low 90s across the lower
deserts, and in the mid 80s in the higher terrain areas. By Friday
the close low will be exiting to the region`s east, and ridging will
begin to build over the west coast. With ridging to the region`s
west, temperatures will begin to warm into the lower to mid 90s
across the lower deserts with the western portions leaning more
towards the mid 90s range.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Another closed low is projected to form from a shortwave trough
originating in the Gulf of Alaska, before developing into a closed
low off the coast of northern California. This will help amplify the
ridge over the Desert SW driving temperatures into the mid to upper
90s throughout the weekend. This next closed low is expected to move
inland into northern California by Sunday evening, which will most
likely return breezy to windy conditions, cooler temperatures, and
possibly some higher terrain rain chances. Continued monitoring of
this system will be needed over the next several days.

&&

.AVIATION...Updated at 1130Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The main aviation weather concern throughout the TAF period will
be the potential for gusty winds and areas of blowing dust this
evening from an outflow boundary moving through. In the meantime,
through this afternoon, generally tranquil conditions will prevail
with winds exhibiting the typical diurnal tendencies with speeds
generally aob 10 kts, with a period of southerly winds late
morning into early afternoon. Thereafter, a complex of showers and
isolated thunderstorms is likely to materialize across southeast
AZ, with the latest guidance indicating an outflow boundary
pushing northward through the terminals generally between the
02-04z timeframe this evening with winds gusts as high as 25-30
kts and areas of blowing dust potentially reducing visibilities to
MVFR conditions. Conditions should improve after 06-07z, with
light easterly winds returning during the overnight period. Mostly
clear skies can be expected through this morning before FEW-SCT
cloud bases between 10-15 kft develop by this afternoon.


Southeast California/Southwest Arizona including KIPL and KBLH:
Gusty westerly winds this evening at KIPL will be the main
aviation weather concern throughout the TAF period. Outside of
this, speeds will generally be light aob 10 kts with a west to
northwest direction prevailing at KIPL and fluctuating between a
northwest to northeast direction at KBLH. Generally clear skies
will prevail early this morning before FEW mid-level cloud bases
at around 12 kft develop during the late morning/early afternoon
hours.

&&

.FIRE WEATHER...
Dry conditions and warming temperatures will be observed through
the weekend. MinRH values will be around 10-15% today before
increasing slightly to 15-20% over the weekend. MaxRH values
tonight will generally range between 30-60% before decreasing
slightly to 20-50% over the weekend. Gusty winds are expected to
increase this evening and over the weekend into early next week,
which could lead to elevated fire weather conditions in some
areas.

&&

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

$$

SHORT TERM...Ryan
LONG TERM...Ryan
AVIATION...Lojero
FIRE WEATHER...95/Ryan