Winterhaven, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

627
FXUS65 KPSR 171011
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
311 AM MST Sun May 17 2026

.KEY MESSAGES...

- Widespread breezy to locally windy conditions are expected this
  afternoon through this evening, and will continue tonight
  through early Monday morning across Southeast California
  following a cold front.

- Elevated to locally critical fire weather conditions are
  anticipated for a few hours this afternoon and evening for the
  Eastern Arizona higher terrain, where a Red Flag Warning will be
  in effect.

- Afternoon high temperatures will be near normal today and then
  drop to 4 to 6 degrees below normal for Monday and Tuesday
  before slowly warming back up again.

&&

.SHORT TERM /TODAY THROUGH MONDAY/...
A broad longwave trough remains across the Western CONUS with a
weak shortwave trough seen moving across northern AZ early this
morning. This weak trough contributed to stronger breezes Saturday
afternoon and evening. The pressure gradient across the region
should relax a touch this morning through midday as the shortwave
departs, but another, more potent, shortwave trough will drop
south through NV this afternoon and evening before progressing
eastward across UT and CO Monday morning. This will lead to a re-
strengthening of the pressure gradient and another increase in
winds across the region, especially during the late-afternoon and
evening hours across southern AZ and southeast CA. Widespread
gusts up to 25-35 mph are expected this afternoon through this
evening, with some areas seeing 40+ mph.

Another round of strong westerly downsloping winds is expected in
Imperial County this evening. Downsloping winds Saturday evening
reached 40-50 mph and similar speeds can be expected again this
evening, if not a touch stronger given mountaintop winds are
forecast to be stronger than last evening. A Wind Advisory has
been issued to include the Imperial Valley again this evening. In
addition to the gusty westerly winds, a dry cold front is expected
to drop south through southeast CA and southwest AZ tonight with
rather strong N-NW post-frontal winds, especially across eastern
Riverside County where gusts up to 40-50 mph are possible. Another
Wind Advisory has been issued for eastern Riverside and northeast
Imperial County for the post-frontal winds tonight through early
Monday morning. Of particular concern are strong crosswinds along
I-10, especially between Desert Center and the Indio Valley, where
HREF probabilities of peak wind gusts >50 mph are maximized
(60%). The strong winds will be capable of generating localized
dust channels that could significantly reduce surface visibility.

The gusty winds this afternoon and evening will also once again
lead to elevated and marginally critical fire weather conditions.
A Red Flag Warning remains in effect for southern Gila County and
the Tonto National Forest where afternoon and evening winds are
forecast to be strongest in combination with minimum RHs of 10-15%
and dry fuels.

Aside from the winds, the passing of the shortwave troughs, even
with them staying to the north, and the cold front passage will
cool temperatures down. High temperatures this afternoon are
forecast to be right around seasonal levels in the low to mid 90s
across the lower deserts. Temperatures drop further for Monday
with lower deserts likely failing to reach 90F (NBM probability of
>90F is 10-20%). Skies will be mostly clear to at times partly
cloudy with high clouds today through Monday. There will also be a
narrow band of PBL moisture and forcing along and just ahead of
the cold front Monday morning. Enough to at least lead to some
lower clouds in south-central AZ near sunrise. There are a couple
HREF members producing a few sprinkle showers out of these clouds,
but overall PoP is under 10%.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As the potent weekend shortwave trough departs the Mountain West,
to drive severe weather in the Plains, a measure of broad
cyclonic flow over the Western U.S. will remain and likely
persist through the remainder of the upcoming work week. Heights
aloft will rebound though, closer to seasonal averages, and so
temperatures are expected to warm through the middle of the week,
with seasonally dry conditions continuing. Meanwhile, a strong
midlevel ridge will remain nearly stationary off the Pacific
Northwest Coast through much of next week, with most global
guidance showing a subtropical jet forming under the ridge and
developing a few weak disturbances. A few of which may be sent
downstream and near/over the Southwest U.S.. Regardless of the
details and how weak troughing over the West- Central CONUS
eventually resolves, essentially all solutions currently show the
region remaining completely dry, with periods of mid-high level
clouds and slowly warming temperatures through the work week.

&&

.AVIATION...Updated at 0535Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The main aviation concerns will continue to be a period of
elevated cross-runway winds at KPHX late tomorrow morning along
with gusty W-SW winds tomorrow afternoon. W-SW winds will remain
elevated (8-13kt) into the overnight hours before going back E-SE
around 08-10Z and decrease to below 10 kt. A period of southerly
crosswinds expected again during the late morning hours with wind
speeds increasing to 10-15kt. Winds will then go W-SW during the
afternoon with gusts up around 20kt. Winds will then increase to
around 25kt around 01-02Z and continue through 06Z. Confidence is
low that winds will go E-SE tomorrow night at KPHX and may just
stay S-SW, so VRB has been entered in the TAF for now. Skies will
remain mostly clear through tomorrow morning with FEW high clouds
moving in tomorrow afternoon and evening.

Southeast California/Southwest Arizona including KIPL and KBLH:
Periods of gusty winds will be the main aviation weather issue
throughout the TAF period. At KIPL, winds will maintain a westerly
component while at KBLH winds will fluctuate from the south to
southwest. At KIPL, wind gusts reaching 25-30 kts at times will
continue into the overnight hours. Winds will then decrease to
around 10 kt early tomorrow morning and continue into the
afternoon. Wind speeds will pick up again early tomorrow afternoon
with gusts of 20-25kt expected. A period of stronger winds
(30-35kt) is again possible tomorrow evening (01-05Z). At KBLH,
winds will remain elevated (10-15kt) over the next couple hours
before decreasing to around 5 kt for the overnight and morning
hours. Wind speeds will then pick up with gusts around 20 kt
beginning during the afternoon hours, a period of higher wind
gusts (around 25kt) is possible during the evening hours (01-05Z).
Skies will remain mostly clear through tomorrow morning with FEW
high clouds moving in tomorrow afternoon and evening.

&&

.FIRE WEATHER...
Elevated and marginally critical fire weather conditions are
expected this afternoon and evening for a few hours as winds
increase across the region. A Red Flag Warning remains in effect
for southern Gila County and the Tonto National Forest for this
afternoon through this evening. The winds will likely steadily
increase through the afternoon, with peak wire weather conditions
(strongest winds and lowest RH) likely between 1500-2000MST. Wind
gusts in the warned area will peak around 25-35 mph and RH values
will minimize around 10-15%. While RH increases above critical
levels after 2000MST the elevated breezes are likely to continue
through midnight, which may make controlling any new/existing
fires challenging. Wind gusts up to 25-35 mph will be common
across all districts this afternoon, but will be strongest across
southeast CA with westerly sundowner winds in Imperial County up
to 40-50 mph and northerly gusts up to 35-50 mph across much of
eastern Riverside County later tonight through early Monday
following a cold front passage around midnight. There will be
very dry air following the front that will create elevated fire
conditions across Riverside County, even during the overnight
hours. Minimum RH values will be closer to 15-20% across the
western districts. Lingering northerly breeziness down the Lower
Colorado River is expected Monday, but this gradient wind should
weaken heading into the afternoon and winds elsewhere Monday
afternoon will be weaker than today with gusts up to 15-25 mph.
Beyond Monday, weather conditions will be seasonally hot and dry
(Min RHs around 5-15%), with winds mostly reaching up to 15-25
mph in the afternoons.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Red Flag Warning from 11 AM this morning to 11 PM MST this
     evening for AZZ133.

CA...Wind Advisory from 11 PM this evening to 7 AM PDT Monday for
     CAZ560-561-564-568>570.

     Wind Advisory until 1 AM PDT Monday for CAZ562.

     Wind Advisory from 4 PM this afternoon to 11 PM PDT this evening
     for CAZ563-566-567.

&&

$$

SHORT TERM...Benedict
LONG TERM...Benedict/Whittock
AVIATION...Berislavich
FIRE WEATHER...Benedict