Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/13/22
Area Forecast Discussion
National Weather Service Phoenix AZ
515 PM MST Sun Jun 12 2022
.UPDATE...
Updated Aviation section.
&&
.SYNOPSIS...
Another day of extreme and deadly heat is expected as high
temperatures across the lower deserts climb to between 110-115
degrees this afternoon. Mainly dry conditions should prevail,
however, isolated high-based thunderstorms containing minimal
rainfall is possible this afternoon mostly across portions of
southeast and east Arizona. A weather disturbance will move across
the western states through early next week, bringing with it a
temporary relief to the extreme heat as well as increase in winds.
Another episode of extreme heat is likely by next Thursday as
another episode of high pressure builds across the western CONUS. An
increase in moisture by end of next week and next weekend favors the
potential for an increase in convective activity.
&&
.DISCUSSION...
The area`s first excessive heat event is now in its fifth (and
final) day as the Excessive Heat Warning remains in effect
through this evening. High to very high HeatRisk will remain the
primary wx impact today with another day of possible record
breaking temperatures. High temperatures are expected to reach up
to 110-114 degrees for most urban and desert locations today with
lows only cooling to the mid-upper 80s, including additional record
breaking warm lows for Phoenix. As of early afternoon Phoenix had
already tied the daily record high of 112 degrees after tieing a
record high of 114 degrees yesterday.
In addition, slight (<10%) chances for mostly isolated afternoon
high based showers and dry lightning thunderstorms will be seen
for SE AZ and the E AZ high country/Mogollon Rim this afternoon.
Early afternoon radar depicted very isolated and weaker convection
well SE and E of Phoenix. The weak upper level disturbance and UL
high has shifted E of the area as depicted on the latest UA plots
and GOES WV imagery as a Pacific trough pushes into the W Coast.
ACARS sounding and SPC mesoanalysis confirm drier air aloft and in
the BL with PW running only slightly elevated at ~0.7-0.8", and
lingering elevated MUCAPE and DCAPE of ~1200-1500 j/kg. Any high
based showers and thunderstorms will likely produce very little or
no precip with their main threat being dry lightning, localized
very strong and gusty winds and patchy blowing dust. HREF shows
the best dust potential in N Pinal Cty near Casa Grande with a 30%
chance of outflow winds of 35 mph.
The Pacific trough continues to advance into the W Coast this
evening, and the Great Basin and north portions of our region
early in the week. Noticeable cooling will result and provide some
relief to our region starting tomorrow and will likely last
through Wed, as highs decrease to around 106-109 degrees, or
Moderate HeatRisk. The trough will is also increasing winds as
afternoon gusts of 25-35 mph look likely for Sun and Mon, with the
stronger winds favoring the western deserts and typical high
terrain areas. As a result, new Wind Advisories have been issued
for W Imperial Cty including the Salton Sea and the Imperial
Valley for Mon afternoon and into Mon night.
For the latter half of the week the Clusters favor the next
strong high pressure system rebounding across the W CONUS.
Currently the Grand Ensemble mean H5 height is still forecast at
~592 dam for Thu. This would result in high HeatRisk and a 1-day
Excessive Heat Event.
By Fri-Sun Clusters favor a very amplified H5 height pattern
featuring a deep W Coast trough juxtaposed with a pronounced
W-Cent CONUS ridge which could put the region of pronounced S flow
and in the path of N MX deep subtropical moisture advection and
disturbance tracks. Moreover by Sat, the top 3 clusters favor at
least some 24 hr QPF across several parts of AZ. Then for Sun all
4 of the clusters favor QPF for AZ. The current preferred NBM
solution favoring 20-30% POPs for Fri, 40% POPs for Sat and 20%
for Sun. The Grand Ensemble storm total QPF for Phoenix is
becoming slightly less bullish at ~0.23". In addition, much cooler
(below normal) highs are favored for next weekend.
&&
.AVIATION...Updated at 0015Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Moderate to strong southwesterly/westerly flow (relative to this
time of year) is in place throughout the troposphere due to an
upper trough centered over the PacNW and SW Canada. This will aid
in late afternoon and early evening gusts of 20-25 kts. Ongoing
thunderstorms over southern Pinal County are not expected to
reach the metro area nor is the outflow from them is not expected
to impact the TAF sites. Winds will slowly weaken tonight and
eventually transition to downvalley drainage patterns after 07Z
(~11Z for KPHX). The downvalley patterns will transition to
upvalley/southwesterly winds fairly early (between 16Z-18Z
Monday). The upper trough will deepen over the western CONUS
tonight and Monday leading to strengthening southwesterly flow. In
turn, surface wind speeds will increase through the afternoon
Monday with gusts of 25-30kts becoming common after 21Z Monday. As
for sky cover, little to no cloudiness.
Southeast California/Southwest Arizona including KIPL and KBLH:
Moderate to strong southwesterly/westerly flow (relative to this
time of year) is in place throughout the troposphere due to an
upper trough centered over the PacNW and SW Canada. This will aid
in late afternoon and early evening gusts of 25-30 kts (possibly
up to 35 kts briefly). Winds will slowly weaken tonight (sooner at
KBLH than KIPL) and trend toward southerly at KBLH (remaining
westerly at KIPL). The upper trough will deepen over the western CONUS
tonight and Monday leading to strengthening winds through the
column during the day Monday. Breeziness redevelops in the 16Z-18Z
time frame with gusts of 25kts common followed by additional
strengthening in the afternoon with gusts of 30-35kts after 21Z.
Anticipate localized dust plumes developing over western Imperial
County leading to areas of lofted dust and reduced slantwise
visibilities in the late afternoon over a fairly large area. Some
additional strengthening is anticipated at KIPL after 00Z with
gusts of 35-40 kts and potential for decreased surface
visibilities in blowing dust. As for sky cover, little to no
cloudiness.
&&
.FIRE WEATHER...
Very hot temperatures are expected once again today across the
lower deserts with highs peaking between 110-115 degrees. There is
a slight chance (less than 10%) of an isolated dry thunderstorm
developing this afternoon across Southern Gila County. A cool down
in temperatures is likely through the first half of the week
(Mon-Wed) with highs falling back below 110 degrees. Another
warmup to temperatures surpassing 110 degrees is likely on
Thursday. Afternoon MinRHs will range between 7-15% through next
Thursday with overnight recoveries between 25-40%. A passing
weather disturbance, responsible for the relief in the excessive
heat conditions, will deliver breezy to locally windy conditions
today and Monday. Wind gusts this afternoon will be between 20-25
mph across most areas with the potential for gust greater than 30
mph late this afternoon into this evening across portions of
Southeast California, especially the Imperial Valley. Stronger
winds are likely on Monday with widespread 25-35 mph gusts,
elevating the fire danger threat with near critical threat across
the higher terrain of south-central Arizona, where a Red Flag
Warning is in effect. Lighter winds are expected the rest of the
week with typical afternoon diurnal breezes.
&&
.CLIMATE...
Daily Record Temperatures:
Phoenix Yuma El Centro
Today: 112 (2019) 117 (1956) 115 (2019)
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST this evening for
AZZ530>556-559>562.
Red Flag Warning from 11 AM to 8 PM MST Monday for AZZ133.
CA...Excessive Heat Warning until 8 PM PDT this evening for
CAZ561>570.
Wind Advisory from 6 PM to 11 PM PDT Monday for CAZ563-566-567.
Wind Advisory from 2 PM Monday to 3 AM PDT Tuesday for CAZ562.
&&
$$
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DISCUSSION...Sawtelle
AVIATION...AJ
FIRE WEATHER...Lojero/Sawtelle
CLIMATE...Kuhlman