Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/16/22
Area Forecast Discussion
National Weather Service Phoenix AZ
458 PM MST Sun May 15 2022
.UPDATE...Updated Aviation Discussion.
&&
.SYNOPSIS...
High pressure overhead will result high temperatures reaching ten
plus degrees above normal today and capable of tying or breaking
a few daily records. High temperatures will then slowly cool for
the next few days. The afternoon temperatures will result in a
moderate heat risk for those sensitive to heat and the necessary
precautions should be taken. Seasonably dry conditions will
persist through the period with mostly clear skies.
&&
.DISCUSSION...
A strong upper level high remains in place with 500 hPa heights
near the 95th percentile for this time of year. Meanwhile, an
upper level trough is approaching from the west, which is
allowing for slightly improved mixing compared to yesterday. The
result is a slightly warmer lower atmosphere. ACARS soundings show
a 1-2 F increase compared to yesterday below 700 hPa. This upper
level low may allow for a few high clouds but these will not have
much if any impact on high temperatures. Overall, high
temperatures will increase slightly compared to yesterday with
most locations 1-3F warmer and approaching record territory. NBM
shows a 20% chance of setting a new record today in Phoenix. For
more details, see the CLIMATE section.
The aforementioned shortwave will also bring an increase in
breezes, especially in the evening hours in Southeast CA, as it
passes over the region through Monday. Sundowner winds in Imperial
county may exceed 30 mph the next couple of evenings, which could
kick up some light dust/sand. In the wake of the shortwave, the
flow pattern is shown to enter a quasi-zonal or weak troughing
setup through midweek. With lower heights over the region,
afternoon temperatures are expected to slowly come down a few
degrees, but NBM still has highs nearing 100 each afternoon in the
lower deserts, with Monday the hottest day of the work week.
Meanwhile lows also remain seasonably warm in the upper-60s to
low-70s, aided partially by nightly shallow moisture fluxes from
the Gulf of California.
Global ensembles continue to strongly support a deeper trough
moving across the western CONUS towards the end of the week,
however, ensemble clusters still have considerable variance in
the depth and timing of this trough. The majority of ensembles
keep the central mid-level cyclonic circulation near the US-Canada
border. So, can at least confidently say the Desert Southwest
will remain seasonably dry and mostly cloud-free with this wave,
but the depth of the trough will influence the magnitude of
cooling at the end of the week and how breezy winds get. The
majority of NBM members dip high temperature back below 100 by
Friday, which is also currently expected to be the breeziest day
across the region. Any elevated breezy days at this point of the
year will result in elevated fire weather conditions as well. By
the end of next week around 80% of all ensemble members support
ridging building back into the region which will most likely lead
to temperatures climbing above 100 degrees once again. The other
ensemble members show another dry trough and temperatures
remaining in the mid to upper 90s.
&&
.AVIATION...Updated at 2350Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation concerns expected through the period with winds
generally favoring a normal diurnal pattern. Light to moderate
winds, AOB 10 kt, with occasional gusts into the mid-upper teens
early this evening will be followed by an E switch by 07-09Z.
Occasionally breezy W-SW winds will be seen by early Sun afternoon
with periodic gusts near 16-22 kts through early Mon evening.
Skies will be clear to mostly clear with FEW high clouds this
evening.
Southeast California/Southwest Arizona including KIPL and KBLH:
The potential for some gusty sundowner winds this evening and
again on Mon evening will be the main weather concern through the
period. For KIPL gusts approaching 25 kts are likely this evening
subsiding by around 08z. At KBLH some breezy SW winds this evening
with gusts in the upper teens will subside by 06Z, followed by a
prolonged period of light and variable conditions. By midday Mon,
S winds AOB 10 kt will prevail at KBLH. FEW-SCT high cloud decks
this evening will be followed by clear to mostly clear skies.
&&
.FIRE WEATHER...
High pressure over the area will result in afternoon temperatures
10+ degrees above normal today, with most lower deserts reaching
the 104-108 range. Temperatures then cool a few degrees for Monday
before hanging near 100 the remainder of the week. Very dry
conditions are expected today with afternoon Min RHs around 2-4%.
Daytime minimums remain depressed at 5-15% for the rest of the
forecast period. Overnight RH recovery will be poor tonight,
around 15-25%, before a slight improvement during the workweek
with overnight shallow moisture fluxes from the Gulf of
California. Areas near the Lower CO River Valley will see the
greatest Max RH improvement, to around 40-50% by midweek, with
elsewhere only to 20-30%. A slight increase in wind is expected
today and Monday, especially in SE California where evening gusts
could exceed 25-30 mph. Otherwise, seasonal winds will prevail,
with afternoon gusts commonly between 15-20 mph. Another wind
increase, and potentially more significant, is expected near the
end of the week, which may elevate the fire danger potential.
&&
.CLIMATE...
Record highs later this week:
Date Phoenix Yuma El Centro
---- ------- ---- ---------
5/15 107 in 1937 109 in 1937 107 in 1934
5/16 106 in 1997 109 in 1956 108 in 2014
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
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DISCUSSION...Hodges/Benedict
AVIATION...Sawtelle
FIRE WEATHER...Hodges/Benedict
CLIMATE...18