Biola, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

589
FXUS65 KPSR 062311
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
411 PM MST Sun Apr 6 2025

.UPDATE...Updated 00z Aviation Discussion.

&&

.SYNOPSIS...
Ridging aloft entering the area will drive temperatures up well
above normal this week starting Monday. The ridge will continue to
build, and expand throughout the week reaching peak strength
Thursday and Friday. Expect highs in the upper 90s with potential
of reaching 100 degrees across the majority of the region by the
end of the week. High pressure aloft will keep skies mostly clear,
and dry conditions will persist.

&&

.DISCUSSION...
The main forecast concern for the coming week will be the building
heat and the likely areas of Moderate HeatRisk developing by
Thursday and lingering through Friday. The upper level trough
is finally ejecting eastward out of our region with increasing
subsidence and ridging filling in behind the system. As H5 heights
increase to between 577-579dm by later on Monday, our region will
undergo modest warming pushing highs to a few degrees above
normal on Monday.

The large scale weather pattern will also become somewhat blocked
with the ridge staying put over the Intermountain West into
central Canada. By Wednesday, stronger ridging situated to our
southwest will shift northeastward into the Southwestern U.S.
Heights aloft will get another boost during this time with H5
heights rising to 584-586dm before eventually peaking on Thursday
at around 588dm. Temperatures will continue to trend upward
through the middle part of the week with highs back into the 90s
starting Tuesday and likely just above 95 degrees on Wednesday.
As the ridging peaks over our region late week, temperatures will
climb further with some lower desert locales likely reaching or
even topping 100 degrees on Thursday and Friday. Local daily
record highs are likely to be in jeopardy for at least Thursday
and Friday (see CLIMATE section below), as a large portion of the
Phoenix Metro has a 70-90% chance of reaching 100 degrees. We
also expect areas of Moderate HeatRisk to develop by Thursday
which will have impacts on those who are sensitive to the heat,
and/or those who have prolonged exposure to the heat without
adequate hydration. Boundary layer conditions will remain
seasonably dry during this time which will at least allow for
efficient nocturnal cooling and overnight lows mostly in the low
to mid 60s outside of the urban core areas.

By next weekend, ensemble guidance favors a large scale trough
moving into at least the Pacific Northwest and likely farther
south toward our region. There is still some model uncertainty
with the strength and the depth of the trough, but there is at
least some evidence it will lead to a brief cooling trend. For
now, the NBM is showing highs falling back to mid 90 degrees by
next Sunday. If any weather system does end up passing through our
region, it is quite unlikely it will contain enough moisture for
any realistic precipitation chances. We have higher chances of
just seeing an increase in winds which could lead to elevated fire
weather concerns.

&&

.AVIATION...Updated at 2310Z.

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

No aviation concerns will exist through Monday afternoon under
mostly clear skies. Winds are expected to follow typical diurnal
tendencies with speeds generally AOB 8 kts. There will also be
extended periods of variable to nearly calm winds at the SE
California terminals.

&&

.FIRE WEATHER...
High pressure will spread into the region over the next couple of
days leading to quieter and drier conditions. Expect generally
clear skies with MinRHs falling to less than 10% area-wide each
afternoon. Overnight recovery will generally be poor with MaxRH
values around 20-25%. Temperatures will also quickly warm over
the next several days with readings reaching above normal starting
Monday before peaking later in the week at around 10-15 degrees
above normal. Overall light winds are also forecast with
directions mostly following diurnal patterns.

&&

.CLIMATE...

Record high temperatures this week:

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

Apr  9   102 in 1989   102 in 1989   104 in 1989
Apr 10   100 in 2018   100 in 1960    98 in 2018
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...None.
CA...None.
&&

$$

DISCUSSION...Kuhlman/Ryan
AVIATION...Whittock/Salerno
FIRE WEATHER...Kuhlman/Ryan
CLIMATE...Kuhlman