Phoenix, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

287
FXUS65 KPSR 231110
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
410 AM MST Mon Jun 23 2025

.UPDATE...Updated Aviation Discussion

&&

.KEY MESSAGES...

- Below normal temperatures through the first half of the week
  followed by a return to above normal as early as Thursday and
  then lower desert highs return to around 110 degrees this
  weekend

- Dry conditions will prevail under mostly clear skies with
  afternoon and evening breeziness (15 to 25 mile per hour gusts)

- Isolated to scattered afternoon thunderstorms in Southeast
  Arizona beginning Tuesday, with slight chances (10 to 20
  percent) in Southern Gila County beginning on Thursday

&&

.DISCUSSION...
A low pressure circulation has broken off from the larger trough
across the west and is seen on WV satellite early this morning
over central CA. According to the latest global models this low,
and another trailing weak shortwave, will not dig too much further
south and will eventually eject northeast through the southern
portions of the Great Basin midweek. The overall trough pattern
will maintain dry southwest flow across SoCal and most of AZ and
maintain sub-seasonal H5 heights over the region. This will lead
to a continuation of cooler than normal temperatures through at
least the first couple of days of the workweek.

Following a rare late-June day where nearly all lower desert
locations failed to reach 100 degrees, today and Tuesday are
forecast to be a few degrees warmer, with most rural locations
reaching the upper-90s and metro and valley locations reaching
around 100-104 degrees. Another couple degrees of cooling is
expected into Wednesday, but with highs still 1-3 degrees short of
daily averages. Mornings through the first half of this workweek
will be pleasant in the upper-60s to middle-70s. Widespread Minor
HeatRisk is expected with these high and low temperatures, which
is not bad for the summer, but a Minor Risk means people
especially susceptible to heat, as well as those with long
exposure, can experience health impacts.

There is great agreement among global ensemble models that the
500mb height field over AZ and SoCal will gradually rise after the
trough in the Southwest breaks down and lifts away during the
middle of the week. H5 heights are expected to go from 586-586dam
today to 591-593dam by the end of this weekend. Surface
temperatures will also rise in sync with the rising pressure. A
return of normal to slightly above normal high temperatures and
Moderate HeatRisk is expected on Thursday. Odds of lower desert
highs >110 then go up this weekend, with around 20-40% chance on
Saturday and 60-90% chance on Sunday, based on the 00Z NBM. Low
temperatures will be a little bit slower to warm up, likely due to
the drier air and clear skies at night, but as they push into the
middle-70s to middle-80s this weekend, the HeatRisk category will
push toward high-end Moderate with localized Major.

Yeah, yeah, enough about the heat, it is the summer after all (but
honestly, please take the heat seriously)! Where are the monsoon
storms? Well, we may not be waiting too much longer to start
seeing some signs of life. There is already some good convergence
of moisture going on in central and northern Mexico that will
funnel up through New Mexico the next few days and even bleed into
southeast AZ by Tuesday. Moisture will not be able to push too
far into AZ initially due to the persistence of the dry southwest
flow aloft. It is going to take some time to get better moisture
(PWATs >1.0") to push further into AZ. Still, some afternoon
isolated to scattered convection is expected to develop beginning
Tuesday, in southeast AZ, mainly east of a line from Tucson to
Globe. There have been some hi-res model runs that bring isolated
convection, and even some morning ACCAS showers, to parts of
southern Gila County, but there has been a trend toward convection
staying southeast and east of Gila County tomorrow and Wednesday.
NBM PoPs are only around 5% both days. PoPs then increase to
around 10-20% Thursday onward, with the latest NBM run.

So, if you are in the Phoenix area you may at least be able to
start seeing some towering cumulus and cumulonimbus way in the
distance starting tomorrow. Once the early-week trough breaks
down, global models show the southwesterly steering flow will
weaken significantly and that eventually, toward the end of this
weekend and start of next week, 500mb winds will start trending
more southerly to southeasterly in southern AZ as a high pressure
circulation tries to set up near the AZ/NM border to Four Corners
area. This would be more ideal to start working better moisture
into the region, from thunderstorm outflows and midlevel gravity
waves and nightly gulf surges from the Gulf of California. A weak
coastal trough toward the beginning of next week may initially
hold back the full breadth of the high pressure and keep some
semblance of a dry southwesterly wind component in parts of the
region, but by around July 4th long-range global models are
favoring the high to strengthen and become more expansive across
the Southwest. So, perhaps we will be talking thunderstorm impacts
in South-Central AZ by the middle to end of next week.

&&

.AVIATION...Updated at 1110Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
No major aviation concerns are expected during the TAF period
under clear skies. Winds will follow familiar diurnal trends, but
the usual shift to the W will occur later than usual resulting in
a longer stretch of S`rly winds this afternoon. Some occasional
gusts in the mid teens to around 20 kts should be anticipated
during the afternoon hours. More consistent breeziness, especially
at KPHX, is being shown in model guidance, warranting the
inclusion of a TEMPO group for some more marginal gusts this
evening at Sky Harbor International.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation weather issues under clear skies are expected
over the next 24 hours. Winds at KIPL will follow familiar diurnal
trends with gusts developing early this evening. At BLH, winds
will favor a S`rly component, with occasional gusts anywhere from
the mid teens to around 20 kts. Much like yesterdays forecast,
wildfire smoke causing VIS reductions will continue to be a low
confidence forecast parameter. However, hazy conditions cannot be
completely ruled out, especially at KIPL, potentially leading to
TAF amendments reflecting lower flight categories in subsequent
updates.


&&

.FIRE WEATHER...
There are no significant fire weather concerns through the next 7
days, aside from perhaps some isolated dry thunderstorm impacts
in parts of southern Gila County (toward the White Mountains)
as early as tomorrow. Seasonal breeziness is expected in the
afternoons and evenings with daily peak gusts up to 15-25 mph.
Conditions overall will remain dry with daily minimum RH values
down to 5-15% and overnight recoveries only to 20-40%. Recoveries
will be worst midweek when many South-Central AZ areas only rise
to 15-20% overnight. Near to below normal temperatures are
expected through Wednesday, but will warm through the end of the
week and lower desert highs will push back to around the 110
degree mark as early as Friday, with continued warming through
the weekend.

&&

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

$$

DISCUSSION...Benedict
AVIATION...RW
FIRE WEATHER...Benedict