372
FXUS65 KPSR 201924
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1224 PM MST Sat Jun 20 2026

.KEY MESSAGES...

- Temperatures will remain near seasonal levels through Monday
  under clear to mostly clear skies.

- Strong high pressure will build back into the region by the
  middle of the upcoming work week, pushing daytime highs to
  around or just above 110 degrees across the lower deserts.

- Minor to Moderate Heat Risk through early next week will become
  widespread Moderate to localized Major Heat Risk during the
  latter half of the week.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...
Very dry and seasonably hot conditions will be the main story
through the rest of the weekend. Moisture has effectively been
scoured out of the column over the last couple days thanks to
enhanced, deep southwesterly flow, with the 12Z KPSR sounding this
morning estimating PWAT just under 0.5" and a notable inversion
between 700-500 mb, indicative of synoptic scale subsidence.
Across the forecast area, dewpoint temperatures in the 20s and 30s
F have become commonplace and will persist into early next week.
The upper level pattern is characterized by a somewhat progressive
northern stream, with troughing over the Northwest US. To the
south, midlevel water vapor imagery and 500 mb RAP analysis
indicate a subtropical high/anticyclonic flow, stretching from off
the Northern Baja all the way through Western TX and the TX
Panhandle. Ensembles remain in excellent agreement that the
subtropical high and associated heights aloft will remain
suppressed as the northern stream troughing progresses into the
Northern Plains this weekend. As a result, rather stable H5
heights in a 588-591 dam range will prevail through Sunday,
representing values between the 70th-90th percentile of
climatology. Despite the positive midlevel height anomalies, very
dry conditions and clear to mostly clear skies will provide for
effective radiative cooling overnight, leading to widespread early
morning lows in the 70s (near to slightly below normals).
Afternoon highs are expected to reach a near normal range, around
105F for the typically hotter lower desert locales.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
By Monday, the broad trough situated to our north is forecast to
eject into the Central Plains followed by the subtropical high
over northern Mexico starting to shift northward into our region.
Monday will be somewhat of a transition day with heights rising to
592-594dm as the high center nears southwest New Mexico and our
flow also shifts out of the south. Forecast highs rise more into
a 105-109 degree range Monday while the first Gulf moisture surge
pushes surface dew points out of the 20s.

Guidance then shows the center of the ridge shifting along the
southern border of Arizona/New Mexico Tuesday into Wednesday with
heights rising more into a 594-596dm range by Wednesday. The
position of the high will help to bring additional Gulf moisture
surges into midweek, likely raising surface dew points into the
low 40s to low 50s Tuesday and upper 40s to mid 50s Wednesday.
This is a slight improvement from what models showed 24 hours ago
and now may be enough for an introduction of low-end PoP chances
only within higher terrain areas. The NBM does not really depict
these chances, but if the moisture forecast holds we may introduce
some isolated 10-15% PoPs for higher terrain locations in
southwest and south-central Arizona on Tuesday and/or Wednesday.
The moisture may end up being enough for convection, but with the
ridge basically being right overhead the subsidence will likely
inhibit convection a good amount. As of right now, the moisture
only looks to last through around Wednesday or at the latest
Thursday as drier westerly flow is suggested again late next week.

Temperatures will continue to heat up through the middle part of
next week as the ridge strengthens and shifts into our region. NBM
forecast highs reach near 110 degrees Tuesday leading to a
widespread Moderate HeatRisk before likely peaking closer to 115
degrees on Thursday. Localized areas of Major HeatRisk begin to
show up on Wednesday as highs reach 110-113 degrees, but more so
on Thursday with forecast highs between 112-115 degrees.
Fortunately, guidance shows another trough moving into the
Northwestern U.S. Wednesday into Thursday before shifting more
into California and the Great Basin Friday into next weekend. As a
result, temperatures are expected to begin to lower starting
Friday, but the 110 degree days may still hold on into Saturday.

&&

.AVIATION...Updated at 1740Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation weather concerns under clear skies can be
expected throughout the TAF period. The overall wind pattern will
favor the typical diurnal tendencies with occasional afternoon/early
evening gusts in the mid to upper teens, otherwise wind speeds
will be aob 7 kt.

Southeast California/Southwest Arizona including KIPL and KBLH:
Gusty winds, especially at KIPL, will continue to be the main
weather issue under clear skies throughout the TAF period. A
westerly wind component will prevail at KIPL while winds will
fluctuate between the south to southwest at KBLH. At KIPL, wind
gusts of 20-25 kts are expected this evening, with some occasional
gusts of 25-30 kts possible. Gusts will taper off during the
overnight hours becoming light and variable. At KBLH, some
occasional gusts into the mid to upper teens are possible during
this afternoon and early Saturday evening hours.

&&

.FIRE WEATHER...
Near normal temperatures and very dry conditions will continue
through Monday with fairly light winds. MinRHs will be in the
single digits each day, while overnight recoveries will be poor,
ranging between 15-35%. Some afternoon and early evening upslope
breeziness will be common, but gusts will mostly stay below 20
mph. The very low RHs and light breezes should lead to elevated
fire weather conditions during the latter half of the
afternoon/early evening hours. Going into the middle part of next
week, moisture will improve raising MinRHs to between 10-15% by
Wednesday, but temperatures will also warm to above normal.
Daytime breeziness should also increase with more gusts reaching
the 20-25 mph range.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

SHORT TERM...Whittock
LONG TERM...Kuhlman
AVIATION...95/Berislavich
FIRE WEATHER...Kuhlman

NWS Phoenix (PSR) Office