Imperial, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

952
FXUS65 KPSR 262149
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
249 PM MST Thu Mar 26 2026

.KEY MESSAGES...

- Unseasonably hot conditions will continue to challenge daily
  temperatures records through the rest of the week and into the
  weekend.

- These hot conditions may be dangerous, especially for any
  strenuous outdoor activities without proper hydration and
  frequent breaks in the shade, or air conditioning.

- Temperatures should finally begin to back away from record
  territory by the end of the weekend as the high shifts east and
  cloud cover and shower chances increase.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...
The center of the strong area of high pressure driving our heat
has shifted to over West Texas and an innocuous shortwave passed
around the northwest side of the high. H5 heights are still around
record level for this time of year over southern AZ and southeast
CA at 585- 588dam. Temperatures today and Friday will continue to
push the 100 degree mark in the afternoons in many lower desert
communities under mostly clear skies. Friday will likely be a
degree or two warmer than today, with some slight warming of the
lower thermal profile. In case you forgot, 100 degrees in March is
highly irregular at 20 degrees above normal. The highs across the
lower deserts to end the week will continue to push daily record
as well. Morning lows will also be quite mild for March, in the
60s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Beginning Saturday the weather in AZ and southeast CA will
finally become more lively, breaking out of the week-long dry,
tranquil, and very hot pattern. A very strong surface high
(1037-1040mb) moving through the Plains Friday and Saturday will
push a backdoor cold front (minus the cold) into southern AZ
Friday night into Saturday morning. A strong pressure gradient
will develop and lead to strong easterly winds across southern AZ
Saturday morning, especially across many high terrain areas east
of Phoenix. Latest ECMWF EFI is highlighting parts of southeast AZ
for a highly anomalous wind event. The 12Z HREF is showing high
probabilities (>80%) of sustained wind speeds above 25 mph
beginning around midnight in the mountains east of Phoenix,
including southern Gila County. There is always uncertainty in the
peak wind forecast with these easterly wind events, as models
often overdo the strength of the winds. So, I would not anticipate
winds hitting 60-65 mph like some of the models are suggesting
for some mountain peaks, but this is still expected to be one of
the strongest gradient winds over the past few years and some
mountainous areas may still see peak winds in excess of 50 mph.
Easterly breezes may increase as early as midnight in the lower
deserts as well, including Phoenix, but the strongest breezes -
gusts up to 25-30 mph - will become more common and widespread
after sunrise Saturday and then the gradient should slowly relax
through the afternoon.

In addition to the wind Saturday, there will be an initial push
of moisture into the region from the east and south, leading to
more mid and high level clouds. After what will likely be a warmer
morning due to the easterly breezes Saturday, afternoon high
temperatures will end up a few degrees cooler than Friday,
especially across south-central AZ. Despite the slightly cooler
temperatures, highs are still forecast to break daily records in
Phoenix, Yuma, and El Centro. Heading into Sunday a better push of
moisture into the region is expected as high pressure shifts
further east to the Gulf States and southerly to southwesterly
flow taps into some subtropical moisture from the south. Ensemble
members continue to show PWATs increasing to around 200-250% of
normal across AZ by late Sunday into Monday. The increased cloud
cover in combination with the high shifted further east will
result in further cooling temperatures. The caveat of coming out
of a wave of historical heat is that even a little bit of cooling
will still result in near record temperatures. Afternoon high
temperatures are forecast to be in the mid to upper 90s across the
lower deserts both on Sunday and Monday and may still tie or
break daily record highs.

The influx of moisture late this weekend will also result in some
low-end shower and thunderstorm chances, with best chances across
the AZ high terrain to the north and east of the Phoenix. NBM
PoPs remain quite low for the lower deserts of central and
southwest AZ, generally under 10%, despite the abundance of
moisture. With the unseasonably hot temperatures, the lower
troposphere and PBL will still be pretty dry. So, showers that do
develop may mostly fall as virga. Additionally, the forcing will
be very limited Sunday through Monday. There is at least some
guidance support for some mid-level confluence and convergence
that could better the chances scattered showers or a band of light
showers. Most global ensemble guidance has the best instability
Monday (few hundred J/kg of CAPE), but with the minimal forcing it
may be difficult to realize any instability to get thunderstorms.
With the dry sub- cloud air, any convective or stronger shower or
storm that develops will be capable of producing gusty outflow
boundaries, but the hope of outflow boundaries generating new
activity is pretty low given LCL heights likely remaining fairly
high for this time of year.

Beyond Monday, ensemble guidance continues to show an East
Pacific trough moving through the region during the middle of next
week. This feature currently looks to drop H5 heights into a
567-575dam range on Tuesday and Wednesday. As a result afternoon
high temperatures are forecast to fall back into the 80s by
Wednesday, which is near to slightly above normal for this time of
year. The last time our region saw afternoon high temperatures in
the 80s was on March 11, which will be 3 weeks past by next
Wednesday. Additionally, this trough will bring additional shower
and storm chances to the region, but as of now primarily favoring
northern AZ. The NBM currently has the best rain chances (20-30%)
across the higher terrain to the north and east of Phoenix. The
latitudinal progression of the trough through the region will
influence whether the rain chances increase across the southern
deserts (a deeper southerly track) for the beginning of April.
Stay tuned for future updates.

&&

.AVIATION...Updated at 1725Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation weather concerns will exist during the TAF period.
Winds will continue to follow diurnal trends with speeds generally
AOB 10 kt. Mostly clear skies will give way to increasing decks
between 15-25 kft AGL later Friday afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation concerns are expected during the next 24 hours under
mostly clear skies. Westerly winds between 5-10 kts will be
favored at each terminal this evening and into the overnight
hours. Occasional gusts into the mid teens cannot be ruled out at
KIPL later this evening. Otherwise, anticipate extended periods of
variability with speeds generally AOB 6 kts.

&&

.FIRE WEATHER...
Unseasonably hot temperatures with very dry conditions will
continue through at least the start of the weekend. MinRH values
will run around 5-15% today through Friday before increasing to
10-20% starting Saturday. MaxRHs will follow a similar uptrend
with readings close to 20-40% the next few mornings before rising
up closer to a 40-60% range. Moisture levels will be highest
Sunday into Monday and Wednesday with some moisture fluxes into
the region. Winds will be light the next couple of days and follow
typical diurnal tendencies. Stronger winds (gusts 25-35 mph)
enter the picture late Friday into Saturday, mainly for areas
east of the Colorado River. There are good chances for higher
gusts upwards of 40+ mph (~80% chance) in the mountainous areas
east of Phoenix. Additionally, winds will be strongest Saturday
morning and then should gradually subside midday through the
afternoon. Although minimum RH values are forecast to stay above
the critical threshold (15%) most of the day, there may still be
a period of elevated, to near critical, fire weather conditions
Saturday due primarily to the widespread breezy easterly winds and
unseasonable temperatures. There will be at least slight chances
for rain (10-20%) Sunday through Wednesday, but the CWR will be
under 10%. Any showers that do develop will be capable of
producing gusty and erratic outflow winds, which could impact any
existing fires.

&&

.CLIMATE...

Daily record highs through this week:

Date      Phoenix         Yuma         El Centro
----      -------         ----         ---------
3/26    100 in 1988     99 in 1988     98 in 1988
3/27     98 in 1986    100 in 1986     99 in 1988
3/28     95 in 2015     98 in 2015     98 in 2015
3/29     97 in 2015    100 in 1897     97 in 1969

&&

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

$$

SHORT TERM...Benedict
LONG TERM...Benedict/Berislavich
AVIATION...Whittock
FIRE WEATHER...Benedict
CLIMATE...RW/18