El Mirage, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

239
FXUS65 KPSR 271733
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1033 AM MST Tue May 27 2025

.UPDATE...Updated 18z Aviation Discussion...

&&

.KEY MESSAGES...

-Seasonably hot and dry through the middle of the workweek, with
 highs in the upper 90s to lower 100s.

-A pattern shift late this week will result in a slight boost in
 temperatures, with highs peaking around 103-108 across the lower
 deserts on Friday and areas of Moderate HeatRisk developing.

-An influx of tropical moisture over the weekend may cool
 temperatures to near normal by Sunday and lead to slight chances
 for showers (20-40%) and isolated thunderstorms for portions of
 Southwest and South Central Arizona.

&&

.DISCUSSION...
The upper level pattern continues to show a defined troughing
feature in the Gulf of Alaska, with ridging over Western
Canada/North West US. A couple of shortwaves can be seen over the
western US in the lower latitudes, this will lead to some localized
breezy conditions this evening. This will primarily affect our more
wind prone areas such as Western Imperial county. Another
consequence of this disturbance remaining in the vicinity through
the middle of the week will be relatively stable temperatures, with
only 1-3 degrees of day-to-day warming expected through Thursday.
Besides shortwaves the region will predominately be under an upper
level ridge resulting to the gradual increase in the temperatures
throughout the work week as mentioned previously. This will cause
highs to be in the upper 90`s to low-mid 100`s.

By Friday the ridge centers over the Great Basin with 500mb heights
around 588-590dm over the region, which is around the 90th-95th
percentile of climatology for this time of year. This will lead to
high temperatures across the lower desert to be between 102-108
degrees Friday and Saturday (5-15% chance of 110 degrees) with
widespread Moderate Heatrisk on Friday. Meanwhile, the trough over
the E Pacific will be forced over the ridge causing the southern
portion of the trough to split off and form yet another cutoff low
which will position off the coast of the Baja Del Norte, resembling
a rex block pattern. Current models show this cut off low remaining
relatively stationary through Saturday as its trapped under the
ridge during this time.

By Sunday evening as the ridge weakens and moves eastward towards
the plains cluster analysis start to vary in the movement of the low
to our SW. This fosters a decrease in confidence for the 5-7 day
forecast. Currently a tropical depression, has a very good chance of
developing (90% chance according to the latest NHC forecast) west of
Mexico is shown decaying as it arrives at the southern tip of the
Baja Peninsula this weekend. As this depression moves north closer
to the cut-off low off the coast of the Baja Del Norte moisture will
be introduce into the Desert SW. Though a few members show this not
coming to fruition, 80-90% of GEFS and EPS solutions show PWATS
increasing upwards of 1-1.25" over the forecast area, well above
200% of normal PWAT values for this time of year. While these values
look hopeful it will depend on the track of the cut off low and we
will have to wait and see how the models come into agreement. For
now, the deterministic NBM shows temperatures moderating near normal
Sunday, and PoPs around 20-35% across Southwest and South-Central
AZ, with best chances focused on Sunday PM into Monday AM. Model
QPF totals have a 10-30% chance of reaching 0.5", but most areas
can more reasonably expect 0.1" or less.

&&

.AVIATION...Updated at 1735Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
No aviation weather concerns will exist during the TAF period
under SCT-BKN high clouds through the afternoon. The overall wind
pattern will exhibit diurnal tendencies with a period of
southerly variability before shifting decidedly SW/W early this
afternoon. Occasional gusts into the mid to upper teens will be
possible this afternoon/early evening, but otherwise, wind speeds
will remain AOB 10 kts.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation concerns are expected through Wednesday morning under
occasional FEW-SCT high clouds and otherwise clear skies. Winds
will favor SE at KIPL and SSE at KBLH through the afternoon and
shift SW for a period this evening into the early overnight hours
at both terminals. Sustained wind speeds will generally remain AOB
10 kts.

&&

.FIRE WEATHER...
Very dry conditions coupled with afternoon gusts in the 10-15 mph
range will result in elevated fire weather conditions, mainly
across SE California, the Lower Colorado River Valley, and S Gila
County this afternoon and evening. Winds will continue this
pattern over the next several days. Afternoon minRHs will fall
below 15% each day, with many locations bottoming out in the
single digits, followed by poor overnight recoveries of 20-40%.
Temperatures will remain near to slightly above normal through
much of the upcoming workweek. A pattern change heading into the
weekend and early next week looks to cool things down slightly and
bring an increase in moisture with at least a slight chance
(20-40%) for rain. However, forecast confidence late this
weekend/early next week is still low at this time.

&&

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

$$

DISCUSSION...Whittock/Ryan
AVIATION...Whittock
FIRE WEATHER...Whittock/Ryan