Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/08/21

Area Forecast Discussion

National Weather Service Phoenix AZ

 431 PM MST Wed Apr 7 2021

.UPDATE...
Updated Aviation section.

.SYNOPSIS...
Above normal temperatures will persist as the Desert Southwest
remains under the influence of high pressure. Thursday is expected
to be the breeziest day for the remainder of the week with gusts
upwards of 20-30 mph possible. Warm temperatures will continue
through the week with highs across the lower deserts expected to
remain in the low to mid 90s. Dry, tranquil conditions are
expected to persist with no chances for rain in the forecast.

&&

.DISCUSSION...
Dry, tranquil conditions will continue to persist across the Desert
Southwest as the region remains under the influence of an upper
level ridge. Phoenix ACARS soundings show a very dry atmospheric
column as PWAT values are around 0.25". At the surface, dew
points across the Valley are in the single digits while higher
values exist across the Yuma area and Imperial County. We`ll see
these moisture values improve some going through the remainder of
the day but dry conditions and mostly clear skies will persist.
Temperatures will rise into the low 90s across the Valley this
afternoon and mid 90s across southwest Arizona and southeast
California.

After rebounding into the 578-582 dm range today, 500 mb heights
will drop slightly tomorrow as a shortwave trough moves through
the Pacific Northwest and into the central Rockies. Although this
system will remain well removed from the region, pressure
gradients will increase and promote breezy conditions going into
tomorrow. Strong winds in excess of 40 mph are expected in far
southwest Imperial County starting tonight. Thus, a Wind Advisory
has been issued for this area for the overnight hours. Breezy
afternoon winds with gusts in the 20-30 mph range will be
possible across much of the forecast area Thursday afternoon. An
additional round of strong, gusty winds will be possible by late
Thursday for southwest Imperial County, with strong gusts
potentially extending further east into the county. Temperatures
will remain fairly consistent through the remainder of the week as
highs finish in the low to mid 90s each day. Overall confidence
in the weather pattern and these temperatures remains high with
very little spread indicated by the NBM. HeatRisk values will
remain in the low category across virtually the entire CWA for the
duration of the forecast.

WPC cluster analysis indicates that the status quo may finally show
signs of breaking about a week away. A couple of scenarios are
presented by ensemble cluster analysis for early next week. One
solution would be a continuation of our current pattern while
another solution shows the west coast ridge migrating northwards and
merging with another area of high pressure near British Columbia.
This second scenario would allow for negative height anomalies to
build over the western CONUS. If this scenario unfolds, lower
temperatures and breezier conditions would be possible. At this
time, precipitation remains unlikely with most ensemble members
staying dry through the forecast period.

&&

.AVIATION...Updated at 2331Z.

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

West winds will predominate through the evening hours, and a few
gusts to 15 kts are possible at any site. Expect surface winds to
weaken later this evening then transition to familiar nighttime
drainage patterns (favoring easterly directions) around mid/late
evening at KIWA/KSDL and around/shortly after midnight at KPHX/KDVT.
As for sky cover, expect only scant amounts of cirrus from time to
time. Somewhat stronger west winds are expected on Thursday with
gusts up into the 20-25kt range likely at times.

Southeast California/Southwest Arizona including KIPL and KBLH:

Winds will favor the west at KIPL and south at KBLH through this
evening. Gusts of 20-25 kts will be common followed by slow
weakening after midnight, especially at KBLH. Wind speeds will
remain elevated overnight out of the west at KIPL, with sustained
speeds near 15 kts potentially stronger at times. Stronger westerly
winds to return Thu afternoon as another weather disturbance passes
to the north. As for sky cover, expect only scant amounts of cirrus
from time to time.

&&

.FIRE WEATHER...
Saturday through Wednesday: A stagnant pattern will allow for
mostly consistent weather conditions through the forecast period.
Temperatures will remain well above normal with highs in the low
to middle 90s at lower elevation locations. There will be day to
day fluctuations in wind speeds with afternoon gusts locally
reaching 20 to 30 mph. Minimum humidities will also be somewhat
lower than normal with values of 5-10% most places. Max RH values
will be on the low side as well with values of 20-35% before
improving this weekend and into early next week with values of
25-50%.

&&

.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 8 PM this evening to 9 AM PDT Thursday for
     CAZ562.

&&

$$

DISCUSSION...Hodges/Smith
AVIATION...Percha/Rogers
FIRE WEATHER...Hodges/Smith