838
FXUS65 KPSR 192202
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
302 PM MST Sun May 19 2024

.SYNOPSIS...
Temperatures this week will be near normal as a couple weather
systems pass through the region, but mainly to the north of our
area. These systems will lead to breezy to windy conditions during
the afternoon and evening hours, with the highest winds and greatest
impacts expected on Monday. There is a slight chance for some virga
and/or sprinkles in south-central AZ tomorrow afternoon, otherwise
dry conditions continue into next week.

&&

.DISCUSSION...
Analysis of upper-level water vapor imagery this afternoon reveals a
closed low off the coast of southern California along with a trough
digging to the southeast in the Pacific NW. Ahead of these systems,
wind gusts this afternoon and early evening are expected to easily
reach into the mid 20s areawide to 30-35 mph across portions of
southeast California. These winds combined with low humidity will
lead to elevated to critical fire weather conditions today. The
aforementioned closed low will move on shore during the overnight
hours and get swept up in the aforementioned trough as it
continues to dig to the SE. This system will bring a cold front to
the area tomorrow, knocking afternoon temperatures down to near
normal (about 5 degrees cooler than today`s forecasted high
temperatures). Moisture will be limited, but some virga and/or
sprinkles will be possible in south-central Arizona during the
early afternoon as the cold front moves through. Winds will be the
main concern tomorrow afternoon and early evening and will likely
reach 25-35 mph across south-central Arizona and 30-45 mph across
southeast California and the Lower CO River Valley. Winds may
briefly gust up around 40 mph in south-central AZ along the front
as it moves through in the early afternoon. These winds combined
with the low humidity will lead to another day of elevated to
critical fire weather conditions.

Broad troughing over Western CONUS will persist through next weekend
along with a few shortwaves sliding to our north throughout the
week. This will help keep temperatures right around or even slightly
below normal heading into Memorial Day Weekend. Aside from the
slight chance of some virga and/or sprinkles tomorrow afternoon, dry
conditions will continue through next weekend. Global ensemble
models are in fairly good agreement that heights aloft will return
to zonal flow and then start to rise early next week. This will
allow for another warming trend and push temperatures back above
normal.

&&

.AVIATION...Updated at 1720Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Persistence of typical diurnal wind tendencies is expected through
the TAF period at all terminals. Winds currently beginning their
veer to the west/southwest. Typical late afternoon gusty westerly
winds as high as 20 to 25 kts. Winds will subside mid evening with
the typical diurnal tendency back to east southeast overnight
into early Monday. Some high clouds will begin to move into the
area late tonight. Some thickening and lowering cloud bases
expected toward 18z but still remaining above 12k feet.

Southeast California/Southwest Arizona including KIPL and KBLH:
Winds will increase from the south-southwest with afternoon speeds
increasing with gusts up to 20-30 kts. Some lighter winds
overnight, before increasing again and becoming gusty again bu
late Monday morning. SKC will prevail through this evening
followed by FEW-SCT high clouds developing Monday morning.

&&

.FIRE WEATHER...
A cold front will move through the region tomorrow knocking
temperatures down to near or slightly below normal along with
brining strong, gusty winds to the region. While some
virga/sprinkles will be possible in south-central Arizona, there
is no chance for wetting rain with this cold front. Throughout the
week, MinRH will be in the single digits for lower elevations and
in the teens across the higher terrain. Overnight recoveries will
be poor to fair and in the 20-40% range. Wind speeds will be the
highest on Monday with widespread gusts as high as 30-35 mph. This
combined with the low RH and dry fine fuels will lead to near
critical thresholds. Land managers should be cautious for rapid,
uncontrolled spread of any ongoing fires or new starts Monday. For
the remainder of the week, afternoon gusts will be in the 20-25
mph range, which will lead to slightly elevated fire danger.

&&

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

$$

DISCUSSION...Berislavich
AVIATION...Frieders
FIRE WEATHER...Berislavich/Kuhlman