Imperial, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

686
FXUS65 KPSR 160758
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1258 AM MST Mon Mar 16 2026

.KEY MESSAGES...

- Persistent high pressure will help keep temperatures running
  above normal through the start of the workweek.

- Further strengthening of the high will result in an
  unprecedented heat wave for March with widespread triple digits
  expected by Wednesday, and widespread readings near 105 degrees
  by Thursday, shattering daily records by as much as 10 degrees.

- An Extreme Heat Watch is in effect for the middle portion of the
  week into the weekend for much of Southeast California and
  Southern Arizona


&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
Early morning analysis reveals the high that has been meandering off
the Pacific Coast starting to nudge closer inland while the
transient trough that passed by this weekend moving east of the
Central Plains. With that trough now out of the regional picture,
much of the western CONUS will experience generally quiet conditions
during the upcoming workweek as that Eastern Pacific high becomes
the dominant feature, deflecting any significant storm systems
off to our north. It will take a bit of time for the ridge to
rebuild enough to produce any significant temperatures changes
over our forecast area, so highs this afternoon will be basically
the same as Sunday with readings for the lower deserts in the
lower to middle 90s. Tuesday is when a more notable bump in temps
takes place as the high finally makes its way on shore, pushing
the warmest air further eastward. Highs then will range generally
in the middle to upper 90s, with a few spots, mainly around the
Colorado River Valley and westward, potentially hitting triple
digits.

Due to the intensity of the previously mentioned ridge and Central
Plains trough, the regional pressure gradient will still be tight
enough to produce some lingering breezy conditions today. The
strongest gusts (25-35 mph) will once again be focused around the
Lower Colorado River Valley, with locally higher gusts possible
over higher ridge top areas. Other higher terrain spots, such as
Joshua Tree NP and areas of South-Central Arizona, may should also
anticipate some marginal breezes, but peak gusts for these
locations should hover closer to 25 mph.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
By Wednesday, the Desert Southwest will find itself directly under
the center of the high, with heights aloft reaching upwards of 592-
594dm. To put things into perspective, sounding climatology data
for Las Vegas, Flagstaff, and Tucson show record H5 heights for
March are around 590dm and April 591dm, 593dm, and 592dm
respectively. That would put this ridge as one of the strongest
ever seen in recorded history for the region, not only for March,
but for April as well. With this setup, the thermal profile will
also approach record levels, with all-time readings for March
looking likely at the H7 and H5 levels. 850mb temps will be close
to all-time March records by this point, helping to push
temperatures at the surface into the triple digits for most of the
lower deserts. The forecasted high for Phoenix on Wednesday is
102 degrees, which if achieved, would become the early instance
of triple digits for the station, besting the previous earliest,
which is March 26th, by 8 days. March 26th, 1988 is actually the
only March date on record where 100 degrees was achieved is
Phoenix, but appears very likely that more days will be added to
that list.

Model guidance has the ridge strengthening even further by Thursday
with heights approaching 594-596dm, easily making this feature one
of the strongest ever seen during this time of year. This will push
temperatures into uncharted territory (at least by late winter and
early spring standards), both at the surface and throughout the
atmospheric column. Highs Thursday through at least Saturday will
range between 103-109 degrees, with even a low end chance for a
few locations to reach 110F during this window. This would put
daily MaxTs 25-30 degrees above normal and daily records may be
broken by 5-10 degrees. On the topic of records, this heat wave
also puts monthly all-time temperatures in jeopardy, as the
values currently stand at 100, 102, and 101 for Phoenix, Yuma, and
El Centro respectively. All of those values could be tied or
eclipsed as early as Wednesday, but if not by then, they almost
certainly will fall sometime between the end of the week and into
the weekend.

Moderate HeatRisk will develop in response to the upcoming abnormal
heat, with even some localized areas of major HeatRisk not out of
the question. Therefore, an Extreme Heat Watch has been issued for
the Lower Colorado River Valley and westward for Wednesday, which
will expand to include much of Southern Arizona by Thursday. If
this watch were to be upgraded to a Extreme Heat Warning, which
almost certain at this point, it would become the earliest heat
warning to go into effect, with the current earliest instance
occurring between April 26th and 30th of 2020.

&&

.AVIATION...Updated at 0500Z.

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

No significant weather issues will exist through Monday night under
thin, high cirrus decks. Confidence is good that wind trends will be
similar to the past 24 hours across the Phoenix metro, though there
may be some variability and odd directions around sunrise.
Otherwise, winds should be weaker in magnitude and shorter in
duration Monday afternoon/evening before reverting to an easterly
component. North winds will be favored over SE California with light
nocturnal westerlies at KIPL and afternoon gusts 20-30kt common at
KBLH.

&&

.FIRE WEATHER...
High pressure will result in temperatures 10-15 degrees above normal
today before increasing to 25-30 degrees above normal by the
middle portion of the week. Abnormally hot and very dry
conditions will translate to MinRH near 10% the next few
afternoons before readings drop closer to 5-10% by Wednesday.
Overnight recoveries will follow a similar downtrend with values
20-40% through Wednesday morning, dropping to 15-35% through the
remainder of the week. Breezy to locally windy conditions will
once again be observed today, mainly over the Arizona high terrain
and the Lower Colorado River Valley, with the strongest gusts
(25-35 mph) focused over the latter area. The breezy conditions,
combined with low RH values will result in elevated to isolated
areas of critical fire weather conditions. However, with the
limited scope of enhanced winds, no fire weather products are
needed at this time.

&&

CLIMATE...

Daily record highs through next weekend:

Date      Phoenix         Yuma         El Centro
----      -------         ----         ---------
3/16     99 in 2007     99 in 2007    100 in 2007
3/17     99 in 2007    101 in 2007    101 in 2007
3/18     95 in 2017     96 in 2017     95 in 2007
3/19     96 in 2017     98 in 2017     96 in 2017
3/20     96 in 2017     99 in 2004     98 in 2004
3/21     97 in 2004    102 in 2004    100 in 2004
3/22     94 in 1990     98 in 2004     96 in 2004

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Watch from Wednesday morning through Sunday evening
     for AZZ530.

     Extreme Heat Watch from Thursday morning through Sunday evening
     for AZZ531>544-546-548>551-553>555-559.

CA...Extreme Heat Watch from Wednesday morning through Sunday evening
     for CAZ561>570.

&&

$$

SHORT TERM...RW
LONG TERM...RW
AVIATION...18
FIRE WEATHER...RW
CLIMATE...18/Kuhlman