883
FXUS65 KPSR 310957
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
257 AM MST Fri Jul 31 2026

.KEY MESSAGES...

- Extreme heat will persist over the region through at least the
  weekend with record to near record temperatures and highs
  topping 115 degrees over much of the lower deserts.

- In response to the very hot conditions, Extreme Heat Warnings
  are in effect regionwide through Monday.

- Drier air over the region will confine any chances for showers
  and thunderstorms over far eastern Arizona high terrain areas
  through at least Monday.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...
A dangerous heat dome continues to strengthen across the
Southwestern U.S. with H5 heights slated to reach climatological
records later today and last through Saturday. The center of the
ridge will settle directly over Arizona today as H5 heights climb
to 598-600dm by late afternoon. The boundary layer has also dried
out enough to limit convective chances over the next 2-3 days,
especially with subsidence increasing due to the strengthening
ridge. Enough residual moisture should still allow for some
isolated showers and weak thunderstorms during the afternoon hours
from the White Mountains into portions of the Mogollon Rim.
Temperatures are forecast to reach near or even possibly break
daily records today through Sunday with the south-central Arizona
lower deserts topping out between 113-117 degrees to as high as
116-120 degrees across southeast California. Overnight lows will
also become even more uncomfortable with most locations only
dipping into the upper 80s to the lower 90s from Friday night
through Sunday night. The Extreme Heat Warning remains in effect
through Monday evening.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The ridge is forecast to weaken Sunday into Monday with H5
heights dropping to 594-596dm or right around the 90th percentile
of climatology. Despite the ridge weakening, the residual heat
dome will take some time to cool as forecast highs Monday only
drop a couple degrees from Sunday`s readings, keeping the HeatRisk
at Major to Extreme for much of the area. As the ridge weakens
and also shifts its orientation some, moisture should begin to
increase again across southeast Arizona on Sunday and then
eventually over all of southern and central Arizona Monday into
Tuesday. As a result, convective potential will tick upwards early
next week, first over the Arizona higher terrain and eventually
into the lower deserts during the middle part of next week. The
expected increase in convection is likely to help to cool things
off Tuesday into Wednesday, dropping the HeatRisk into a high-end
Moderate to low-end Major. There is still a good amount of
uncertainty as far as the storm chances during the first half of
next week, so any delay in the moisture may result in having to
extend the Extreme Heat Warning another day or so for portions of
the area.

&&

.AVIATION...Updated at 0900Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:

No significant weather concerns will exist through Saturday morning
under periods of mid/high cloud decks. Uncertainty continues
regarding wind forecasts this morning. Confidence is low whether
wind directions will be able to maintain a light easterly component
following an early morning boundary or just go be variable for a few
hours. Confidence is very good that west winds will return by late
morning with some modest gusts in the afternoon. Odds of winds
shifting easterly tonight are better. A few high-based showers may
infringe on the eastern edges of the Phoenix area early Saturday
morning, but confidence in timing and location is too low to include
in TAFs.

Southeast California/Southwest Arizona including KIPL and KBLH:

No significant weather issues will exist through Friday night under
mostly clear skies. Trends in winds should be similar to the past 24
hours featuring a preference towards a southerly direction at KBLH
and SE at KIPL. Variability may become common during the morning
hours while some modest afternoon gusts will be possible at KBLH.

&&

.FIRE WEATHER...
Strong high pressure will persist over the region through the
weekend while relatively dry air confines any rain chances to
over far eastern Arizona. Expect daily MinRHs mostly between
10-15%, while falling overnight RHs offer only little to modest
relief. Record to near record temperatures are also forecast today
and through the weekend. Winds will mostly follow diurnal
patterns, but west southwesterly winds will be dominant much of
the time with afternoon gusts of 15-20 mph at times.

&&

.CLIMATE...
Record high temperatures:

Date       Phoenix         Yuma         El Centro
----       -------         ----         ---------
Jul 31   116 in 2020    119 in 1957    119 in 2020
Aug 1    116 in 1972    117 in 1993    118 in 1993
Aug 2    114 in 2025    117 in 1918    117 in 1969
Aug 3    116 in 2024    116 in 1998    117 in 2021

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning until 8 PM MST Monday for AZZ530>563.

CA...Extreme Heat Warning until 8 PM PDT Monday for CAZ560>570.

&&

$$

SHORT TERM...Kuhlman
LONG TERM...Kuhlman
AVIATION...18/Benedict
FIRE WEATHER...Kuhlman
CLIMATE...18

NWS Phoenix (PSR) Office