378
FXUS65 KPSR 141742
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1042 AM MST Sat Jun 14 2025

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- Temperatures will heat up this weekend, with highs peaking near
  daily records on Sunday, resulting in areas of Major HeatRisk.

- An Extreme Heat Warning is in effect through Monday evening for
  high temperatures ranging from 106 to 114 degrees across the
  lower deserts.

- A dry weather disturbance will pass north of the area early next
  week, resulting in breezy afternoon winds and a slight dip in
  temperatures into the middle part of next week.

&&

.DISCUSSION...
Hot and seasonably dry conditions are forecast to prevail through
next week as a blocking weather pattern keeps a sub-tropical ridge
largely in control across the southern U.S. This blocking pattern
will keep cut-off lows positioned over the northern Pacific and
over northeastern Canada, allowing ridging to stay across the
southern U.S. and at times over the central U.S. This pattern will
keep dry west-southwesterly flow over the Desert Southwest through
next week keeping any monsoon moisture well to our southeast.

As we have stated over the past several days, the main concern for
our region through next week will be the potential for hot
temperatures running beyond 110 degrees and areas of Major
HeatRisk. The sub-tropical ridge is currently centered just to
our south southeast and is expected set up over southern New
Mexico and northern Chihuahua later today and remain there through
early Monday. H5 heights over our region have risen since
yesterday and are likely to peak on Sunday at 592-594dm. The
higher heights will push our daytime highs a couple of degrees
warmer today to around 110 degrees across the lower deserts and
another 3-4 degrees warmer on Sunday as highs reach to between
110-114 degrees. This will mark our hottest temperatures so far
this year and push some areas into the Major HeatRisk category on
Sunday. The Extreme Heat Warning goes into effect later this
morning and lasts through early Monday evening.

Models continue to show a weak and dry shortwave trough passing
through our region later Monday into Tuesday, but trends over the
past day or two show it will be even weaker and a bit farther
north. As a result, NBM guidance has raised forecast temperatures
for the middle part of next week. We should see highs dip below
110 degrees for most locations on Tuesday, but just barely and the
ridge is likely to quickly push back into our region by next
Thursday. Guidance is also showing a bit higher heights once it
moves back into our region, very similar to what we are expecting
on Sunday. Although the latest NBM guidance shows highs mostly
topping out between 109-112 degrees next Thursday, this is only a
couple degrees away from tipping into the Major HeatRisk category
again. At least guidance then shows another trough moving into the
Northwestern U.S. by next Friday/Saturday and if this holds true
it should keep temperatures from getting any hotter and may lower
highs back to just below 110 degrees by next weekend. Beyond next
weekend, long-range guidance is still trying to bring in some
marginal moisture from the southeast, but overall the pattern
still doesn`t look favorable for any meaningful monsoon
conditions.

&&

.AVIATION...Updated at 1740Z.

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

No aviation concerns are anticipated through the forecast period,
with wind speeds mostly remaining at or below 8 kts and following
typical diurnal directional trends. Periods of variability
between transition periods will be common. FEW high cirrus will
overspread the region through this evening.

Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation concerns are expected through the TAF period. Winds
at KIPL will favor a E/SE component, with a period of light S/SW
winds this evening, while KBLH will see a predominant S
component. Wind speeds will remain light aob 8 kts at KIPL through
most of the period, while KBLH will see 10 kt winds during the
daytime hours, with lighter winds during the overnight hours. FEW
passing high cirrus will progress over the area through this
evening.

&&

.FIRE WEATHER...
Strong high pressure will continue to bring hot and seasonably
dry conditions this weekend, with high temperatures as hot as 110
to 114 degrees across the lower deserts on Sunday. Winds will
continue to follow typical diurnal (upslope and downvalley)
tendencies with periods of modest afternoon upslope breeziness
(gusts upwards of 20 mph at times.) Overnight recoveries will
continue to be poor areawide, generally between 20-30%, while
afternoon minRHs dip to between 5-10%. A dry weather system will
pass north of the region late Monday into Tuesday, resulting in a
slight uptick in winds across much of the area Monday
afternoon/evening. These gusty winds combined with dry fuels and
very low humidity could result in elevated fire weather concerns.
Little will change through the rest of next week as day to day
conditions remain hot and dry, but with only some periodic
afternoon breezes.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning until 8 PM MST Monday for AZZ530>544-
     546>556-559>562.

CA...Extreme Heat Warning until 8 PM PDT Monday for CAZ562>567-569-
     570.

&&

$$

DISCUSSION...Kuhlman
AVIATION...Smith/Benedict
FIRE WEATHER...Whittock/Kuhlman