049
FXUS65 KPSR 202331
AFDPSR
Area Forecast Discussion
National Weather Service Phoenix AZ
431 PM MST Fri Jun 20 2025
.UPDATE...Updated 00z Aviation Discussion...
&&
.KEY MESSAGES...
- Extreme Heat Warnings remain in effect across south-central Arizona
through this evening as lower desert high temperatures range
from 103 to 111 degrees.
- A Red Flag Warning is in effect from through Saturday evening
across the higher terrain to the north and east of Phoenix as
very dry and windy conditions lead to elevated to critical fire
weather conditions.
- A cooling trend into early next week will lead to near to below
normal temperatures persisting through much of next week.
&&
.DISCUSSION...
Water vapor imagery showing a dry southwest flow feeding into AZ
ahead of an advancing trough moving through the Pacific Northwest.
This advancing trough is of interest for the region as lowering
heights displace the extreme heat, but continued dry conditions
and increasing winds will result in an increase in fire weather
concerns.
Into Saturday evening, breezy to locally windy conditions will be
observed with winds gusting 20-30 mph with locally higher gusts
expected in the higher terrain to the north and east of Phoenix
and across portions of western Imperial County. Some wind gusts
will continue to gust just above 40 mph in the far SW corner of
Imperial County this evening and tomorrow evening, so have issued
a Wind Advisory for that area. Otherwise, these strong winds in
combination with very dry conditions (minRHs of 4-10% today and 8-
15% tomorrow) will lead to elevated to critical fire weather
conditions. The highest fire weather risk exists across the higher
terrain to the north and east of Phoenix. Therefore, the Red Flag
Warning continues for southern Gila County and the higher terrain
in eastern Maricopa and northeast Pinal Counties into Saturday
evening.
The aforementioned trough will continue to push into our area
through the weekend, which will continue to lower heights aloft and
allow for further cooling. Temperatures will fall to near normal on
Saturday and fall slightly below normal on Sunday. Sunday is
forecasted to be the coolest day of the next week, with current
forecasted high temperatures of 96-104 degrees. The trough will
linger overhead through the middle of next week keeping temperatures
slightly below normal. By the latter-half of next week the
aforementioned trough will weaken enough allowing heights to rise,
which in turn will allow for temperatures to return to near to
slightly above normal readings.
As for Monsoon moisture? Global ensemble members continue to show a
battle between dry air and more moist monsoon conditions over our
CWA beginning around Tuesday. The aforementioned Pacific trough will
work to keep dry air and southwesterly flow in place, at least over
SE CA and western AZ. But, some deep moisture over northern Mexico
looks to make its way into SE AZ. This moisture, in combination with
upper level support, could lead to some isolated to scattered
thunderstorms beginning around Tuesday. This supports some low end
chances for showers and storms as far north as the White Mountains
and into Gila County. Global ensemble members show this moisture
hanging around through the week, which the current NBM is showing as
daily low-end thunderstorm chances for this area.
&&
.AVIATION...Updated at 2325Z.
South Central Arizona including KPHX, KIWA, KSDL, KDVT:
Some gusty southwesterly winds during the afternoon/early evening
hours will be the main aviation weather issue through Saturday
under clear skies. West to southwest winds will continue to gust
in the 20-25 kt range through early this evening before speeds
diminish after 03-04z aob 10 kts. Easterly winds will then take
hold during the overnight through early morning hours before
gradually switching out of a southerly component during the mid-
morning hours and then out of the southwest during the early
afternoon hours with afternoon gusts once again reaching 20-25 kts
at times. Some slight haziness due to lofted smoke from a
wildfire in Mexico will be possible, but should not have any
significant impacts on operations.
Southeast California/Southwest Arizona including KIPL and KBLH:
Gusty westerly winds will be the main aviation weather issue
through Saturday under clear skies. Westerly wind gusts upwards of
25-30 kts can be expected through this evening and once again for
Saturday afternoon and evening at both sites with gusts
potentially exceeding 30 kts at times at KIPL. Some reduced
visibilities, but likely remaining P6SM, due to haze from lofted
smoke from a wildfire in Mexico will possible at KIPL at times.
&&
.FIRE WEATHER...
A Red Flag Warning is in effect through Saturday across the higher
terrain to the north and east of Phoenix where critical conditions
will exist. Expect a combination of low humidities from 5 to 15
percent and late day gusty winds that will range from 30 to 40
mph. All other districts, elevated fire weather conditions will be
noted with slightly lower wind gusts from 20 to 30 mph. Humidity
recoveries overnight will also be poor, only recovering into the
20 to 30 percent range. Temperatures will lower through the
weekend into early next week with near to even slightly below
normal.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning until 8 PM MST this evening for AZZ534-
537>544-546>556-559>562.
Red Flag Warning until 8 PM MST Saturday for AZZ133.
CA...Wind Advisory until 11 PM PDT Saturday for CAZ562.
&&
$$
DISCUSSION...Berislavich/Frieders
AVIATION...Lojero
FIRE WEATHER...Berislavich/Frieders