851
FXUS65 KPSR 030601
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1101 PM MST Thu May 2 2024

.UPDATE...Updated 06z Aviation Discussion.

&&

.SYNOPSIS...
Slightly above normal temperatures are anticipated through
Saturday with lower desert highs reaching the lower 90s each
afternoon. A dry weather system will pass through the
Intermountain West this weekend resulting in widespread breezy to
windy conditions and cooler temperatures on Sunday and Monday. Dry
weather will continue with steadily rebounding temperatures
through early next week.

&&

.DISCUSSION...
Early afternoon visible satellite imagery showed mostly clear skies
across much of the Southwest with some CU development occurring
over some terrain/orographic features across Arizona. Temperatures
so far this afternoon have climbed into the upper 80s to lower
90s across the lower deserts and low to mid 80s across higher
elevation areas such as Globe and San Carlos. Temperatures going
through the remainder of the afternoon will top out near to
slightly above normal in the low 90s across lower elevation
locales while light winds persist.

The warm, tranquil weather conditions is owed to persistent quasi-
zonal flow across the Desert Southwest while broad scale troughing
continues north of our area over the northwest CONUS. Heights will
remain steady through the end of the week as 500 mb heights across
our area remain around 573-575 dm. Thus, temperatures will remain
consistent over the next couple of days as highs remain in the lower
90s with continued widespread Minor Heat Risk. Light winds will
persist through tomorrow before ramping up Saturday in response to
our next approaching weather system.

Confidence continues to increase in a closed low diving southward
along the West Coast for the end of the week before progressing
inland across the Great Basin Sunday. Ensemble cluster analysis
shows consistency amongst global ensembles continues to increase
related to how this weather system will evolve with some minor
discrepancies surrounding its magnitude. While the greatest negative
height anomalies will reside to the north of our area, we will see
an increase in strong winds along with cooler temperatures this
weekend. ECMWF EFI indicates anomalous winds for parts of our
area, particularly southeast California, this weekend while the
greatest anomalies remain displaced further to the north of our
area across places such as the northern Arizona high terrain. The
latest NBM shows probabilities for 40+ mph winds increasing
upwards of 80-90% across portions of southeast California,
primarily Imperial County, Saturday afternoon/evening. Thus, have
issued Wind Advisories for portions of Imperial County beginning
Saturday afternoon, though these may need to be expanded and
extended into Sunday as we get closer. Dust channels may develop
across dust prone areas as a result of these strong winds, which
can reduce visibilities and make travel hazardous. Sunday, a cold
front associated with this system will sweep through the area,
dropping temperatures well below normal across southeast
California and southwest Arizona where NBM highs are in the upper
70s to low 80s across the lower deserts. Strong winds spread east
across Arizona Sunday with gusts to 30-40 mph possible (>60%)
across portions of south-central Arizona. While we will see a
brief spike in moisture, with PWATs increasing to around 0.7-0.9"
along/ahead of the front, rain is not expected with NBM PoPs near
zero for the entire area.

Longwave troughing will continue to be reinforced over the
Intermountain West through Monday which will also feature near to
slightly below normal temperatures and continued breeziness across
the region. Heading into the middle of next week, temperatures look
to slowly rebound to slightly above normal, however the overall
longwave troughing pattern across the Western CONUS looks to
persist.

&&

.AVIATION...Updated at 1720Z.

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

No aviation weather concerns under clear skies are expected
through the TAF period. Wind pattern will continue to exhibit
diurnal tendencies, with easterly winds overnight transitioning to
a period of southerly winds through the early afternoon hours
tomorrow before a full transition out of the west. Wind speeds
will generally remain aob 10 kts.

Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather concerns under clear skies are expected
through the TAF period. Winds will generally be southerly through
the period at BLH aob 12 kts, while southerly winds at IPL
expected to become westerly during the evening hours tomorrow.

&&

.FIRE WEATHER...
Warm and dry weather with light and diurnal winds will continue
through the remainder of this week. Afternoon highs will top out
around 2-4 degrees above normal through Saturday. A dry weather
system will pass north of the region on Sunday, resulting in
widespread breezy to windy conditions and slightly cooler
temperatures. Winds could gust in excess of 40 mph across parts of
SE California Saturday afternoon and evening and again Sunday
morning/afternoon, while gusts climb to 30-40 mph across
southcentral AZ on Sunday. Afternoon min RHs will bottom out
around 8-20% over the next few days, while overnight recoveries
remain in the poor to fair category between 30-60% for most areas.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 3 PM Saturday to 5 PM PDT Sunday for CAZ562.

     Wind Advisory from 3 PM to 11 PM PDT Saturday for CAZ563-566-567.

&&

$$

DISCUSSION...Smith
AVIATION...Young
FIRE WEATHER...Smith/Salerno