688
FXUS65 KPSR 151953
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1253 PM MST Wed May 15 2024

.SYNOPSIS...
Above normal temperatures will continue through at least the
weekend with lower desert highs warming from the mid to upper 90s
Thursday to just over 100 degrees on Saturday. Typical
late afternoon and early evening breeziness along with mainly dry
conditions will persist. Isolated afternoon shower and
thunderstorm activity will occur over the high country through
Thursday, which could cause some erratic, gusty winds that could
make their way into portions of the lower deserts each evening.

&&

.DISCUSSION...
The main concern through the forecast period will be the continued
elevated fire weather concerns due to the hot temperatures, low
humidity, and late afternoon/early evening breezy conditions.

Ensembles in overall agreement with lowering heights through
Thursday as a weak upper low moves across the region. This system
will enduce isolated showers and thunderstorms across the high
country to the north. Not seeing any rainfall across the Phoenix
valley, but some virga and a few sprinkles are possible overnight
tonight and in eastern areas late Thursday. With steering flow
from the north, a bit higher outflow winds from the north could
penetrate south this evening and again late Thursday. The best
chance for this would be for La Paz and northern Maricopa Counties
this evening and then eastern Maricopa County and over Gila
County late on Thursday. There could be some local gusts upwards
of 30 mph, especially in eastern areas on Thursday. This system
will keep temperatures in check, but still hot, mainly into the
middle to upper 90s for Thursday.

For Friday and through the weekend, heights again build across
the area ahead of troughiness developing along the west coast into
early next week. This will push temperatures up several degrees.
Lower deserts will see more widespread 100 to 105 degree readings.
The minor HeatRisk will increase into the moderate category
beginning Friday and into Saturday. This higher heat will be short
lived with temperatures coming down a few degrees and closer to
normal levels by next week.

For next week, a southwesterly flow will dominate with the trough
across the western CONUS. This will keep the daily risk for
afternoon breezy to windy conditions with temperatures closer to
normal levels in the mid 90s. This along with relative humidities
in the single digits, will maintain an elevated fire weather risk.

&&

.AVIATION...Updated at 1740Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The primary aviation weather concern continues to be the potential
for gusty northerly outflows reaching the terminals by 03Z-04Z
this evening due to decaying convection over the higher terrain.
KDVT and KSDL still have the greatest chance (40-50%) of seeing
gusty winds of around 25-30 kt between 03Z-05Z this evening.
Confidence has also risen to around 30-40% at KPHX and KIWA,
however gusts are not expected to be as strong. The outflow
boundary will likely weaken after 06Z, however isolated sprinkles
and/or virga showers will be possible through sunrise. Apart from
gusty winds later this evening, wind directions will follow their
typical diurnal tendencies, with some afternoon breeziness. High
clouds will increase in coverage through tonight, becoming
scattered around 12 kft to possibly BKN at 20 kft.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns are expected through the forecast
period. Winds will favor a westerly component at KIPL, with
speeds generally aob 7 kt through the early evening. Gusts will
increase to around 20 kts at KIPL after sunset and continue for
most of the night. At KBLH, winds will maintain a S-SW component
through most of the period, with occasional gusts around 15-20 kts
late this evening. Mostly clear skies with a few passing mid to
high level clouds can be anticipated.

&&

.FIRE WEATHER...
Elevated fire weather conditions will remain across the area
through the forecast period as dry fine fuels combine with
localized gusty winds, hot temperatures and low relative
humidity. Late day gusty winds of 20 to 25 mph will be common each
day. Although, into Thursday, the higher terrain will also see
isolated high based shower and thunderstorm activity which could
result a few higher gusts and erratic winds dropping south into
the valley. These stronger winds will be most likely across
northern portions of Maricopa and La Paz counties this evening and
over Maricopa and Gila counties Thursday afternoon/early evening.
Minimum humidity values will mainly be in the 10 to 15 percent
range into Friday, before dropping back into the single digits for
Saturday and beyond. Temperatures will top out about 5 to 10
degrees normal through the weekend before coming down closer to
normal for next week.

&&

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

$$

DISCUSSION...Frieders
AVIATION...Salerno/Berislavich
FIRE WEATHER...Frieders