Ogilby, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

459
FXUS65 KPSR 061700
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1000 AM MST Sun Oct 6 2024

.UPDATE...Updated Aviation Discussion.

&&

.SYNOPSIS...
Lower desert high temperatures near 110 degrees are expected for
at least two more days before finally trending slowly downward.
Unfortunately high temperatures will still be near daily records
through most of the week for many locations with minimal relief
from a midweek disturbance. Temperatures are forecast to cool
more, but still remain above normal, as another disturbance moves
in heading into next weekend.

&&

.DISCUSSION...
Only two more days of lower desert high temperatures near the
110F mark are expected before temperatures finally begin a slow
downward turn across the region. Despite the downward turn,
afternoon high temperatures are still forecast to be near or
breaking daily records - which are in the lower 100s - through the
coming workweek as highs reach around 10 degrees above normal
(see CLIMATE section below). Normal highs this time of year are in
the lower 90s. Abnormally strong high pressure and fairly
stagnant dry air continues to drive the 110 degree heat. The H5
height field and 850mb temperatures lower slightly by the middle
of the week as a very weak trough pushes in from the west and
draws a little bit of moisture and clouds into the Desert
Southwest. The NBM adds very low PoPs (<10%) to the region Tuesday
and Wednesday, but any rain shower will be most favorable over
higher terrain areas and likely low impact. The clouds could help
block the sun at times and temporarily alleviate afternoon heat.
However, the clouds and slight uptick in moisture do not look like
they will be enough to keep some areas, like Phoenix, from
reaching Major HeatRisk again on Tuesday. For this reason the
Excessive Heat Warning has been extended through Tuesday now just
for the Phoenix area.

By the end of the week and into the weekend global models remain
consistent in showing a trough moving into the Western CONUS from
the Eastern Pacific, but uncertainty increases considerably in
what this trough will do once pushing inland. The majority of
ensemble members at least have this trough influence the weather
conditions in the Desert Southwest, but they also keep the trough
pretty weak. Looking at the latest ensemble clustering the biggest
variance in the large-scale synoptic pattern for the Western CONUS
appears tied to the uncertainty in amplification of upstream
PacNW ridging and Eastern Pacific troffing behind the trough
moving inland at this week. Ridging in the Northwest would open
the door for the trough late this week to close off somewhere in
the Desert Southwest, which is being hinted at by individual
global models, including both the latest GFS and ECMWF
deterministic runs. While this sounds like a nice change and may
bring rain and cooler temperatures to the region this is still a
week away and reality may still be temperatures well above normal
and little to no rainfall for much of the region. Time will tell.

&&

.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 are anticipated through the TAF period
under mostly clear skies. Overall wind pattern will continue to
exhibit the typical diurnal tendencies with light speeds mostly aob
7 kts. There will likely be extended periods of very light/calm and
variable winds, especially during the periods of diurnal
transitions. Otherwise, a few gusts into the teens may mix down
mid to late morning Monday across the Phoenix area.

&&

.FIRE WEATHER...
Very dry and extreme heat conditions will continue for many areas
through Tuesday, with lower desert highs ranging between 104-112
each afternoon. MinRH values in the afternoons in the 5-10% range
will be common through at least Tuesday, while MaxRH readings are
expected to be between 20-30%, with locally higher values in Yuma
and Imperial Counties. The driest conditions are expected today
through Monday afternoon, with RH values under 25% in most areas
for the next 36-48 hrs. An increase in winds above the surface
during the overnight hours, this morning and again tonight/Monday
morning, may lead to very localized elevated fire weather
conditions in South-Central AZ. Easterly winds during the
overnight hours on and near ridgetops will be capable of reaching
25-35 mph at times, mostly in the mountains east of Phoenix.

There will be a very slight increase in moisture beginning midweek
that may keep MinRH values from falling into the single digits,
but most areas will still see 10-20% readings in the afternoon
through the end of this week. There will also be potential for
some regional rain showers with the moisture increase, but at this
time the chances are very low (5% or less) across the lower
deserts and CWR is near zero. Winds, beyond Monday, will follow
familiar diurnal trends, with occasional afternoon gusts near
15-25 mph.

&&

.CLIMATE...

Record highs through Friday:

Date        Phoenix         Yuma         El Centro
----        -------         ----         ---------
Oct 6     105 in 1917    108 in 1980    106 in 1964
Oct 7     104 in 1991    108 in 1987    105 in 1991
Oct 8     104 in 1987    107 in 1996    106 in 1996
Oct 9     103 in 1996    106 in 1996    104 in 1996
Oct 10    105 in 1991    107 in 1991    105 in 1996
Oct 11    102 in 1991    107 in 1950    106 in 1995

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Monday for AZZ530>536-538-
     539-553>555-559.

     Excessive Heat Warning until 8 PM MST Tuesday for AZZ537-540>544-
     546-548>551.

CA...Excessive Heat Warning until 8 PM PDT Monday for CAZ562-566-567-
     569-570.

&&

$$

DISCUSSION...Benedict
AVIATION...Smith/Whittock
FIRE WEATHER...Benedict
CLIMATE...18