027
FXUS65 KPSR 032353
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
453 PM MST Fri May 3 2024

.UPDATE...Updated Aviation Discussion.

&&

.SYNOPSIS...
Slightly above normal temperatures are expected through tomorrow,
with afternoon highs peaking in the low to mid 90s across the
lower deserts. A dry weather system will traverse the
Intermountain West this weekend leading to widespread breezy to
windy conditions Saturday evening and Sunday, as well as cooler
temperatures on Sunday and Monday. Dry weather will persist
through next week, and temperatures are expected to rebound into
the low 90s by early next week.

&&

.DISCUSSION...
Dry, warm weather continues across the region today as quasi-zonal
flow persists across the southwestern CONUS. Afternoon visible
satellite imagery showed mostly clear skies persisting across the
CWA as dry southwesterly flow aloft continues. Through tomorrow, 500
mb heights will remain consistent around 572-575 dm for our area and
thus high temperatures tomorrow will be similar to today`s in the
low to mid 90s across the lower deserts. Light winds today will give
way to increasingly stronger winds starting tomorrow in response to
an approaching weather system that will impact the region this
weekend.

The aforementioned weather system is currently seen on satellite WV
imagery off the Pacific Northwest coast. Guidance show this closed
low diving southward along the West Coast through the start of the
weekend before progressing inland across the Great Basin Sunday.
Though the greatest negative height anomalies will remain north of
our area, decreasing heights and increasing gradients will promote
strong winds and cooler temperatures as we head through the weekend.
Strong winds will pick up across southeast California starting
tomorrow afternoon/evening, particularly across Imperial County and
Joshua Tree National Park where gusts are likely (>80%) to exceed 40
mph at times. Wind Advisories are in effect for these areas and the
Wind Advisory for much of Imperial County is now in effect through
Sunday evening. Sunday, strong winds will spread across Arizona as
the closed low moves inland across the Great Basin while the
associated dry cold front moves through the region. Wind gusts are
likely (>70%) to climb upwards of 30-40 mph across much of the
forecast area, while some areas may see gusts in excess of 40 mph at
times, particularly areas across Imperial County and southern Gila
County. Additional Wind Advisories may be needed for some areas as
we get closer. The strong winds this weekend may lead to the
development of dust channels across dust prone areas, which could
reduce visibilities and make travel hazardous.

Outside of the strong winds, temperatures will fall below normal
Sunday, especially across southeast California and southwest Arizona
where well below normal highs are only forecast to top out in the
upper 70s to low 80s with the passage of the cold front. Across
south-central Arizona, temperatures won`t see as significant of a
drop with lower desert highs Sunday in the mid to upper 80s.

The closed low will eject to the northeast for the start of the new
workweek with lighter winds prevailing across the region. Global
ensembles then favor longwave troughing persisting across the
western CONUS through much of next week. Temperatures will gradually
warm back up near to slightly above normal with daily afternoon
highs across lower elevation areas climbing into the low to mid
90s.

&&

.AVIATION...Updated at 2353Z.

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

Southerly winds with variability at times and fluctuating speeds
are expected through about 00-01Z before W to SW becomes more
consistent. Sustained speeds will remain mostly aob 8 kts with
a few gusts this evening up to 15-20 kts. Easterly winds should
return by 09-10Z tonight. Very similar conditions are forecast for
Saturday with southerly variability midday/early-afternoon with
late afternoon gusts to around 20 kts. FEW to SCT high clouds will
pass over the area at times.

Southeast California/Southwest Arizona including KIPL and KBLH:

Winds will generally be southerly through the period at BLH aob
10 kts, while southeasterly winds at IPL are expected to become
westerly during the evening hours. Similar conditions are expected
through Saturday morning before winds increase in the afternoon
and evening. Southerly winds at KBLH will increase up to 15-20 kts
in the afternoon with peak gusts up to 25-30 kts. Winds will be
stronger at KIPL in the late-afternoon and evening with westerly
winds up to 20-25 kts and peak gusts in excess of 30 kts. Skies
will remain mostly clear through the TAF period.

&&

.FIRE WEATHER...
Warm and dry weather will persist into this weekend, with light and
diurnal winds and typical afternoon breeziness today. Afternoon
highs will remain slightly above normal through tomorrow in the
low to mid 90s across the lower deserts. Gusty winds will begin to
increase across the region in response to an approaching weather
system starting Saturday afternoon/evening, particularly across
parts of southeast California where gusts are expected to exceed
40 mph at times. Strong winds increase across Arizona heading into
Sunday afternoon with gusts across south-central and southwest
Arizona climbing upwards of 30-40 mph and some gusts potentially
exceeding 40 mph, particularly across southern Gila County. The
strong winds and dry conditions will lead to elevated to locally
critical fire weather conditions this weekend. Min RHs through the
weekend will be around 10-20%, while overnight Max RHs will be
around 30-60% for most areas.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 3 PM Saturday to 9 AM PDT Sunday for CAZ560.

     Wind Advisory from 3 PM Saturday to 8 PM PDT Sunday for
     CAZ563>567.

     Wind Advisory from 3 PM Saturday to 11 PM PDT Sunday for CAZ562.

&&

$$

DISCUSSION...Smith
AVIATION...Benedict
FIRE WEATHER...Smith