308
FXUS65 KPSR 270941
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
241 AM MST Sat Apr 27 2024


.SYNOPSIS...
A departing weather system will result in residual breeziness and
some showers across the higher terrain areas of eastern AZ today.
Thereafter, as high pressure settles over the region, a benign
weather pattern with a warming trend will ensue with temperatures
warming into the nineties across the lower deserts next week.

&&

.DISCUSSION...
Latest water vapor satellite imagery early this morning shows a
large upper-level low spinning near the Four Corners Region. This
low pressure system will continue to gradually lift east-
northeastward into the central Rockies throughout the day. Enough
of a pressure gradient will still be in place for some residual
breeziness to materialize this afternoon through early this
evening across the region, with peak gusts ranging between 20-30
mph. In addition, energy rotating on the back side of the low
will spark some convective shower activity this afternoon across
the AZ High Country, with some of the activity making its way into
southern Gila County. These showers for the most part are
expected to rather unimpactful with very light accumulations
expected, if any. Otherwise, with the negative height anomalies
persisting across the region, temperatures once again will remain
below normal with highs topping out in the low to mid 80s across
the lower deserts.

Once the troughing feature quickly lifts northward into the central
and northern Plains on Sunday, high pressure will begin to settle
across the region with upper-level height fields on the rise. As a
result, temperatures will be on a warming trend with highs expected
to rise back up to near normal levels with readings in the upper 80s
across most of the lower desert communities.

Heading into next week, a more quasi-zonal flow will be in place
across the region as a series of shortwave troughs moving through
the northwest CONUS will limit any sort of ridge amplification
across the Desert Southwest. With 500 mb height fields rising into
the 576-578dm range early next week, temperatures will continue to
warm even further into the low 90s on Monday and then into the mid
90s on Tuesday across the lower deserts. With not much change in the
height fields through the rest of next week due to the quasi-zonal
flow in place, little change in temperatures is expected during
the mid to late week time frame. With the majority of the
shortwave energy remaining well north of the region, a mostly
benign weather pattern will be in place through all of next week
with dry conditions and winds remaining on the lighter side with
just the typical afternoon breeziness.

&&

.AVIATION...Updated at 0525Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Winds will be the primary weather issue through Saturday night as
isold SHRA/TSRA and associated 080-100 AGL cigs currently skirting
the far northern parts of the Phoenix metro quickly exit the region
around midnight. Low forecast confidence exists regarding exact
evolution of winds overnight given the effects of the SHRA creating
oscillations between a NW and SW component, but model evidence
continues to support a lack of the traditional easterly switch
overnight. Renewed gusts around 20kt should be common across the
area Saturday afternoon with more usual directional/speed behavior
resuming Saturday evening.

Southeast California/Southwest Arizona including KIPL and KBLH:
Gusty winds will continue to be the primary weather concern through
Saturday evening under mostly clear skies. W/SW winds should
continue to gust above 25kt at KIPL into the overnight hours with
less gustiness at KBLH. Through the mid/late morning, trends among
forecasts suggest a veering to a NW direction during daylight hours
Saturday. Periodic gusts may resume Saturday afternoon and evening
though forecast confidence regarding the duration of stronger gusts
is low.

&&

.FIRE WEATHER...
Residual breeziness from a departing weather system can be
expected for today with afternoon and early evening gusts ranging
between 20-30 mph. Some showers may affect the far eastern
districts later today. MinRHs will range between 15-20% across the
lower deserts to 30-40% across the far eastern districts. A
significant warming trend takes place Sunday through early next
week with little change in temperatures expected by the middle to
latter of next week. With the warming temperatures, RH values will
trend downward through next week with MinRHs generally ranging
between 10-15%. Winds beginning Sunday and continuing through most
of next week will generally be on the lighter side with the
typical afternoon upslope breeziness expected.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory until 5 AM PDT early this morning for CAZ562.

&&

$$

DISCUSSION...Lojero
AVIATION...18
FIRE WEATHER...Lojero