Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/04/23

Area Forecast Discussion

National Weather Service Phoenix AZ

 422 PM MST Fri Mar 3 2023

.Update...Updated Aviation

&&

.SYNOPSIS...
A mostly dry and tranquil weather pattern is expected through at
least the next 7 days. A warming trend is expected through the
weekend with highs climbing into the lower 70s by Sunday with
little change in temperatures through the middle of next week.

&&

.DISCUSSION...
Drier, quieter weather now prevails across the southwestern CONUS
as quasi-zonal flow dominates our current weather pattern.
Meanwhile, the strong winter storm that brought rain, snow, and
strong winds to our region is now seen pushing through the
Midwest where it is sparking severe weather. The latest ACARS
soundings show some remaining low level residual moisture around
850 mb, which combined with daytime heating has allowed for some
cumulus development across central Arizona. Abundant insolation
will help pushes afternoon highs into the upper 50s to low 60s
across the Valley today, while areas along and west of the Lower
Colorado River Valley will top out in the upper 60s to around 70
degrees.

Heading through the weekend, a trough is set to move into the
Pacific Northwest with a ~150 kt jet max over the Great Basin.
Impacts across our forecast area look to be minimal given that
this system will be removed to the north of us. However, we may at
least see some increased breeziness from this system, primarily
across southeast California where gusts upwards of 20-30 mph are
possible this weekend. We`ll also see an increase in cloud cover
this weekend as this system feeds in high clouds over the Desert
Southwest. Otherwise, dry, tranquil weather conditions will
continue through at least the first part of next week as our area
stays under a quasi-zonal/broad cyclonic regime. Global ensembles
keep 500 mb heights consistently around 565 dm through the
weekend before pushing closer toward 570 dm early next week.
Temperatures through the weekend and into the first part of next
week will warm up to near normal readings as lower desert highs
push into the lower 70s for most places.

Uncertainty increases heading into the latter part of next week as
GFS, ECMWF, and CMC ensemble members show a great deal of
disagreement in regards to timing and position of troughing over
our area. Ensemble cluster analysis shows that the most favored
solution (~35% of ensemble members) as of now would be for any
troughing to remain to the north before amplified upper level
ridging builds in for the end of next week. However, other
ensemble members favor a deeper trough over us during this time.
The main implications that can be drawn from this will be the
outcome of our temperatures, along with any potential breezy
conditions and precip chances. The deeper trough solution would be
more in favor of cooler temperatures, increased gusty wind
potential and perhaps some rain chances, while solutions favoring
amplified upper level ridging building in would allow for above
normal temperatures potentially reaching 80 degrees. The latest
NBM indicates about a 30-40% chance for reaching 80+ degrees
across the lower deserts late next week. The average first 80+
degree temperature for Phoenix is February 3rd, so we are now
sitting a month behind the normal first date of occurrence. As of
now, NBM shows a large spread (~15 degree difference in
interquartile range) in possible high temperatures for the end of
next week indicating the high uncertainty. More to come as we get
closer.

&&

.AVIATION...Updated at 2320Z.

South-central Arizona including KPHX, KIWA, KSDL, and KDVT and
Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation concerns during the TAF period. Light and diurnal
winds expected across the Phoenix area with periods of
variability, while SE California can expect light and variable
winds through the evening. FEW high cirrus clouds will will be
present at all terminals.

&&

.FIRE WEATHER...
A gradual warming trend is expected through the weekend.
Temperatures, however, will still remain slightly below normal.
Winds for the most part will remain light to moderate through next
week, with the exception this weekend across portions of
southeast California where some enhanced breezes with gusts over
20 mph can be expected. MinRH values through the weekend will
range between 20-30%, falling below 20% by early next week with
good overnight recovery.

&&

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

$$

DISCUSSION...Smith
AVIATION...Worley
FIRE WEATHER...Lojero