Eagle Mountain, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

038
FXUS65 KPSR 111701
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1001 AM MST Fri Apr 11 2025

.UPDATE...Updated 18z Aviation Discussion.

&&

.SYNOPSIS...
Abnormally warm conditions will continue over the next few days as
high pressure continues to dominate over the region. A series of
weak systems will traverse through the western United States
starting Saturday, helping to provide a bit of cooling and periods
of locally breezy conditions. Enhanced winds, combined with very dry
conditions, will result in elevated fire weather concerns,
especially for higher terrain areas east of the Phoenix metro, this
weekend.

&&

.DISCUSSION...
Morning atmospheric analysis reveals the CONUS split between strong
ridging across the western half, and transient troughing
encompassing much of the eastern half. With anomalously high
geopotential heights (2 standard deviation above climatology),
abnormally warm conditions (at least for this time of year) will
be the norm through the end of the work week and into the start of
the weekend, with many lower desert locations likely seeing
triple digit high temperatures. 100 degrees was achieved at Sky
Harbor Airport, as well as many other locations across our
forecast area, yesterday, which is atypical as, on average,
Phoenix does not see its first triple digit readings until May
2nd. In fact, with the century mark now being reached in 2025,
yesterday is now tied for the 4th earliest occurrence of triple
digit readings on record for PHX. As alluded to above, yesterdays
heat will not an isolated case, as temperatures this afternoon
will potentially even be a few degrees warmer with lower desert
highs ranging from 99 to 104 degrees. There is a high likelihood
(80-90%) that daily temperature records at our three climate sites
(Phoenix, Yuma, and El Centro) are tied are even broken this
afternoon.

Global models continue to show a quick moving trough exiting off the
eastern Pacific toward the Pacific Northwest and Northern Rockies by
Saturday. This system will pass far off to our north but its
influence will still be felt across portions of the Desert
Southwest. This disturbance will help to push the persistent
ridge`s axis further to the east and push down heights aloft,
indicating some cooler air working its way south across the Great
Basin. However, there will be a bit of some lag time before we see
temperatures cool down more noticeably as the NBM is still
calling for highs in the upper 90s and few spots reaching triple
digits once again Saturday afternoon. The main impact observed
will be an increase in winds, especially for higher terrain areas
east of Phoenix, thanks to a tightening of the pressure gradient.
Max gusts over these higher elevation areas will reach near 25 to
30 mph, and when combined with very dry conditions already in
place, will result in locally elevated fire weather conditions
Saturday afternoon. The aforementioned trough will exit toward the
Northern Plains by Sunday, but residual breeziness will keep fire
weather concerns elevated through this timeframe as similar gusts
are anticipated for the same areas.

The relatively cooler air mentioned above will eventually push
temperatures down by Sunday, but readings are still expected to
remain above-normal for this time of year in the lower to middle
90s. Even with models projecting a few more weak disturbances moving
onshore off the eastern Pacific over the course of next week,
temperatures are not expected to fluctuate much, so values in the
90s will be common. There is a bit of uncertainty during the
latter half of next week regarding the approach of one of these
disturbances. The NBM reflects this uncertainty through the
current temperature spread from next Thursday through Saturday
with MaxT 25th-75th percentile differences ranging near 8-12
degrees. Looking at model ensembles is where we uncover why this
spread exists as some favor a weaker and more progressive system,
while others favor a slower moving and slightly stronger system.
The strength will determine the magnitude of cooling that may
occur, while the timing of this potential system will determine
when the greatest cooling may happen. Nonetheless, these systems
will be undercutting a broad ridge over the western CONUS so
above-normal temperatures are likely to continue. Depending on the
eventual strength of these troughs, relatively enhanced winds may
return at times during the upcoming week, and with very dry
conditions expected to remain in place, locally elevated fire
weather danger will have to continue to be monitored over the
coming days.

&&

.AVIATION...Updated at 1700Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather concerns under some passing high clouds can be
expected throughout the TAF period. The overall wind pattern will
continue to exhibit the typical diurnal tendencies with speeds
generally under 10 kts. There will likely be periods of very light
and variable winds to even calm conditions.

&&

.FIRE WEATHER...
Abnormally hot conditions with temperatures across many of the
lower desert locations reaching into the triple digits can be
expected over the next few days. A cooling trend is expected by
the end of the weekend through next week, however, temperatures
will still remain above normal. MinRHs through the next several
days for most of the area will remain in the single digits with
poor overnight recoveries. Winds through Friday will remain light
and follow the typical diurnal trends, with some occasional
afternoon upslope breeziness. By the weekend, as a weather system
passes to the north, winds are expected to increase across the
region with widespread afternoon/early evening peak gusts between
20-30 mph, with locally higher gusts in excess of 30 mph across
the eastern districts. The combination of the gusty winds and very
dry conditions will result in elevated to locally critical fire
conditions. A couple of additional weather systems will likely
affect the region next week resulting in enhanced breeziness and
thus more elevated fire weather concerns.

&&

.CLIMATE...

Record high temperatures this week:

Date       Phoenix        Yuma        El Centro
----       -------        ----        ---------

Apr 11   99 in 2023    101 in 1936   100 in 2018
Apr 12   99 in 1936    102 in 1962   103 in 1940

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Red Flag Warning from 11 AM to 8 PM MST Saturday for AZZ133.

     Fire Weather Watch from Sunday morning through Sunday evening
     for AZZ133.

CA...None.
&&

$$

DISCUSSION...RW
AVIATION...Lojero
FIRE WEATHER...Lojero/RW
CLIMATE...Kuhlman