275
FXUS65 KPSR 061928
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1228 PM MST Sat Jul 6 2024

.SYNOPSIS...
Extreme heat will continue to be the main weather story
heading through most, if not all of, next week as strong high
pressure remains entrenched over the region. Daily high
temperatures across the lower deserts will continue to top out at
115+ degrees. Some moisture return will bring increased
thunderstorm chances back to the Arizona high terrain and
southeast Arizona by the middle of next week.

&&

.DISCUSSION...
Extreme heat will continue to be the main weather concern heading
through next week. Strong high pressure currently situated near
northern CA will slowly drift eastward to near the AZ/NV/UT
border through the middle of next week with 500 mb height fields
expected to range between 594-597dm. Northerly flow will continue
to keep moisture levels pretty low, resulting in mostly clear
skies and consequently near zero storm activity. The combination
of the enhanced 500 mb height fields in combination with the
mostly clear skies will result in the continuation of extreme
temperatures into next week with highs across the lower deserts
expected to range between 112-120 degrees, with the highest
readings across the western deserts. Temperatures of these
magnitudes will continue to result in widespread major to locally
extreme HeatRisk. Thus, Excessive Heat Warnings remain in effect
through at least Tuesday. Therefore, if partaking in outdoor
activities it is crucial to protect yourself and others from the
extreme heat by taking all the necessary precautions such as
hydrating frequently, wearing light and loose fit clothing, taking
frequent breaks in the shade, and avoiding strenuous outdoor
activities during the hottest part of the day. Heat of this
magnitude can become deadly!

Once of the center of the high pressure moves to near the AZ/CA/NV
border by the middle of next week, the flow pattern will become
better suited for some moisture intrusion into AZ to the point
that isolated thunderstorm activity will more likely develop
during the afternoon hours across the higher terrain areas of
eastern AZ such as the Mogollon Rim and the White Mountains.
However, the conditions across the lower deserts will still remain
too dry for thunderstorms to pop up and this will likely remain
the case through the end of next week as ensemble mean PWATs don`t
show values approaching 1" until next Friday the earliest. It is
likely that the extreme heat will continue through the latter half
of next week across the lower deserts and thus the current
Excessive Heat Warnings in effect through Tuesday will likely
needed to be extended for another couple of days.

Once the center of the high moves into the Four Corners Region by
next weekend, a more favorable flow pattern for deeper moisture
advection is expected as PWATs are expected to rise north 1"
across the region. Thus, the chances for storms at least for the
south-central AZ lower deserts will be on the increase. With the
increased moisture, temperatures are likely to trend cooler and
below the excessive heat threshold.

&&

.AVIATION...Updated at 1710Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation concerns are expected during the TAF period. Winds
will follow diurnal tendencies with occasional afternoon gusts in
the mid-teens, upwards of 20 kts. Mostly clear skies will prevail
through Sunday morning.

Southeast California/Southwest Arizona including KIPL and KBLH:
SE`rly winds will continued to be favored at IPL, with speeds
generally aob 10 kts. At BLH, S`rly winds will prevail, with brief
periods of gusts (20-25 kts) this evening and perhaps again by the
mid-morning hours Sunday. Clear skies can be expected through the
forecast period.

&&

.FIRE WEATHER...
Hot and dry conditions will prevail across the area through much
of next week as strong high pressure dominates. Excessively hot
temperatures with highs generally between 112-120 degrees are
expected across the lower deserts each day. Daily MinRH values
through next week will fall to or below 15% across the lower
deserts, while higher terrain areas in Arizona will mostly see
10-20%. Overnight recoveries will mostly fall in the 30-50% range.
Winds will be fairly light most days and follow diurnal trends,
occasionally gusting to 20 mph during the afternoon hours. The
breeziest day looks to be Sunday, primarily across eastern
districts, with afternoon wind gusts up to 20-30 mph. The
combination of the very hot and dry conditions will lead to an
increased fire danger threat.

&&

.CLIMATE...

Record Highs

           Phoenix      Yuma      El Centro
          ---------    -------   -----------
July 6    116 (1942)  117 (2018)  118 (1966)
July 7    118 (2017)  118 (2017)  121 (2017)
July 8    115 (1985)  118 (1958)  117 (1942)
July 9    116 (1958)  119 (1958)  117 (1958)
July 10   115 (1958)  118 (1959)  116 (2021)

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Tuesday for AZZ530>555-559.

CA...Excessive Heat Warning until 8 PM PDT Tuesday for CAZ560>570.

&&

$$

DISCUSSION...Lojero
AVIATION...RW
FIRE WEATHER...Benedict
CLIMATE...Kuhlman