Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/12/22
Area Forecast Discussion
National Weather Service Flagstaff AZ
815 PM MST Sat Jun 11 2022
.SYNOPSIS...High pressure will continue to deliver the hottest
temperatures so far this year through Sunday. Nn approaching dry
weather disturbance will result in gusty southwest winds on Sunday
with increased fire danger. On Monday, winds become even stronger
with dangerous fire weather conditions developing across all of
northern Arizona. High pressure will build back later in the week
with the potential for another push of monsoon moisture by Friday.
&&
.UPDATE...The widely scattered showers have diminished across
northern Arizona this evening, with clearing skies expected over
much of northern Arizona overnight. Low temperatures will be well
above normal once again. Expect hot temperatures again tomorrow, a
couple of degrees lower than today`s highs.
A trough passing north of Arizona will bring gusty winds on
Sunday, and even stronger winds on Monday. The strong winds,
combined with very low RH will lead to dangerous fire weather
conditions Sunday and Monday. Lighter winds will relieve the fire
threat somewhat on Tue and Wed, but rising temps will increase the
heat impacts by Thursday.
Models are continuing to be consistent with digging a strong
trough off the West Coast late in the week, which will help to
promote a surge of moisture from the south by Friday. An increase
in shower and thunderstorm activity is expected Friday and
Saturday.
The current forecast is in good shape, and no updates are planned
at this time.
&&
.PREV DISCUSSION /237 PM MST/...High pressure in the mid to upper
levels was centered over the southwestern states Saturday
afternoon. Over the coming days this high will be pushed south
and eastward as a dry trough swings across the southwest United
States.
Tonight...Thunderstorms ending after sunset as drier air spreads
across the area. Otherwise, a few clouds, light winds and
seasonable overnight lows.
For Sunday...The dry trough approaches with high pressure
beginning to push to the southeast. Look for a near shutdown for
the threat of thunderstorms as drier air moves in. In addition,
surface pressure gradients will strengthen with gusty southwest
winds at 10 to 25 mph developing. The result will be increasing
fire danger, especially across the northwest corner of Arizona
where a Red Flag Warning is in effect. The shift in the high will
result in 3 to 5 degrees of cooling compared to Saturday`s highs.
Phantom Ranch will remain in an Excessive Heat Warning through
Sunday with all other locations dropping below criteria.
On Monday...The trough digs into Arizona with dry and windy
conditions. The threat for rapid fire growth and spread will be
high with a Fire Weather Watch in effect. It will be cooler still
by about 5 degrees. Look for widespread southwest winds at 20 to
30 mph with gusts over 40 mph, especially along and north of the
Mogollon Rim with patches of blowing dust from Interstate-40
northward.
From Tuesday onward...The trough moves eastward with high
pressure gradually building back over Arizona from the east. Late
in the week moisture will begin to move northward under this
pattern, enhanced by the approach of a slow moving trough off the
west coast. The result will be the development of a moist
southeasterly flow from over the Gulf of California and northwest
Mexico. Models are fairly determined to develop a good chance of
thunderstorms by Thursday or Friday and looking at the pattern, we
can`t argue.
&&
.AVIATION...For the 06Z TAF package...VFR conditions persist for the
next 24 hours with clearing sky cover expected. Gusty southwest
winds return for Sunday afternoon from 16Z-03Z. Anticipate sustained
winds of 15-20 kts with widespread gusts of 25-35 kts at all
regional terminals during this time. Minor turbulence for general
aviation aircraft is likely. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Hot and dry conditions will continue on Sunday.
Gusty southwest winds return for Sunday afternoon with peak gusts of
30-45 mph expected. A Red Flag Warning remains in effect for
portions of northern Arizona on Sunday due to the stronger winds and
low humidity. Even stronger winds are forecast for Monday with a
Fire Weather Watch in place.
Tuesday through Thursday...Winds will decrease some on Tuesday, but
minimum RH values remaining below 15 percent. Lighter winds are
expected on Wednesday and Thursday with little to no precipitation
likely.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Monday morning through Monday evening
FOR AZZ104>118-137>140.
Excessive Heat Warning until 8 PM MST this evening FOR AZZ018-
037-038.
Red Flag Warning from 11 AM to 8 PM MST Sunday FOR AZZ104>109-
112-139-140.
Excessive Heat Warning until 8 PM MST Sunday FOR AZZ005-006.
&&
$$
PUBLIC...BAK/McCollum
AVIATION...LaGuardia
FIRE WEATHER...LaGuardia
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
450 PM MST Sat Jun 11 2022
.UPDATE...Updated 00Z Aviation Discussion.
&&
.SYNOPSIS...
Extreme and deadly heat will continue through this weekend as lower
desert high temperatures reach 110 to 115 for most places each
afternoon with minimal overnight recovery. Mainly dry conditions
will prevail, although isolated showers and thunderstorms producing
little rainfall will be possible across the eastern Arizona high
terrain through at least Sunday. A few isolated convective showers
cannot be ruled out in parts of Southwest Arizona and Southeast
California as well today. The heat should briefly lessen early next
week, as temperatures fall back closer to normal but climb again
during the later half of next week. An increase in moisture very
late in the week favors at least a slight chance of precipitation.
&&
.DISCUSSION...
The area`s first excessive heat event is now in its fourth day as
the main Excessive Heat Warning remains in effect through Sunday
evening. High to very high HeatRisk will remain the primary wx
impact this weekend with record breaking temperatures forecast
through Sun. High temperatures are expected to reach 111-116 degrees
for most urban and desert locations through Sun with lows only
cooling to the mid-upper 80s to 90, including continued record
breaking warm lows for Phoenix. As of early afternoon Phoenix had
already tied the daily record high of 114 degrees after setting a
record high of 113 degrees yesterday.
In addition, slight chances for mostly isolated afternoon high based
showers and dry lightning thunderstorms will be seen this
afternoon/early evening for near I-10 between W Maricopa Cty and
Desert Center, CA, and continue for the high terrain areas of the
Mogollon Rim, E and SE AZ this afternoon as well as Sun afternoon.
Early afternoon radar already showed convection popping in the W-SW
deserts and eastern high terrain. This is due to a weak but sizable
upper level disturbance as depicted on the latest GOES WV imagery as
a swath of elevated upper and some mid level moisture extending from
SE to N AZ. The disturbance has managed to integrate itself in the
midst of the UL ridge. Models show that the strength of the ridge
will now slowly weaken. The relatively weak flow aloft will allow
the disturbance to linger with the UL high through this weekend. The
disturbance is also associated with anomalously elevated PW of just
under an inch, or ~90-97.5% of climatology, across parts of the
region and support the aforementioned weekend convection through
Sun. ACARS and SPC mesoanalysis shows more elevated MU CAPE above H7
ranging from 500-1800 j/kg, forecast DCAPE >2100 j/kg and slightly
increased BL moisture at 925-850mb. HREF members and the UAWRF GFS
remain in good agreement on the weekend`s convective prospects
including the strong and gusty outflows. The 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.
The excessive heat is likely to break by early next week as models
depict a Pacific trough advancing into the W Coast on Sun, 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 Mon and will likely last through Wed, as highs decrease to
around 106-109 degrees, or Moderate HeatRisk. The approaching trough
will also increase 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.
For the later half of the week the Clusters favor the next strong
high pressure system moving and building across the W CONUS.
Currently the Grand Ensemble mean H5 height is now forecast at ~592
dam for Thu. This would result in high HeatRisk and a 1-day
Excessive Heat Event.
By Fri Clusters favor a very amplified H5 heights 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 every cluster features at least some 24 hr
QPF across several parts of AZ. The current preferred NBM solution
favoring 10-20% POPs for late Thu/Fri and 20-30% POPs for Sat. The
Grand Ensemble QPF is becoming slightly more bullish ranging from
upwards of 0.2" to ~0.33".
&&
.AVIATION...Updated at 2350Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Current gusty west winds will continue thru the mid-evening hours,
with gusts climbing upwards of 25-30 kts before subsiding after
sunset. Outflows moving into the Phoenix area from dissipating
thunderstorms could increase speeds a bit more over the next couple
of hours as well. There is a chance that blowing dust from these
outflows could make its way to KDVT and even KPHX, but any
visibility restrictions are expected to be very minimal, with KVDT
seeing the best chance of a reduction down to 5-6 SM. Winds switch
back to the east overnight with speeds remaining below 8 kts. Gusty
westerly winds to return on Sunday with lighter westerly winds
persisting well into Sunday night. Skies will remain mostly clear
with some mid and high clouds at times.
Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns expected through the period. Current
southeasterly winds at both KIPL and KBLH to become southwesterly by
early/mid-evening. Winds gust in the 20-25 kt range to subside
during the evening/overnight hours. Gusty southwesterly winds to
return Sunday afternoon/early evening with only modestly lighter
winds Sunday night. Mostly clear skies are favored to continue thru
the TAF period.
&&
.FIRE WEATHER...
Very hot temperatures and slight chances for dry thunderstorms
will be the main concern through at least Sun. Chances for storms
will mostly be in S Gila County through Sun, however isolated
convective showers and dry lightning thunderstorms are just as
likely in parts of SE CA and SW AZ today. Dry storms will be
capable of producing new fire starts and outflow winds could
create sudden strong wind shifts. Lower desert highs will be
around 110-115 today through Sun before cooling back to near
normal by Tue and storm chances diminish after Sun. The "cooldown"
will be brief as highs climb back to around 110 by Thu. Afternoon
Min RHs will mostly be between 5-15% each day, while overnight
recoveries vary between 20-40%, with the driest period during the
middle of next week. The passing wave to the north bringing the
"cooldown" will also produce very breezy conditions, likely on Sun
and Mon, with widespread 25-32 mph gusts. Stronger gusts, up to
37 mph will be possible in SE CA and high terrain areas in
general. The strong winds and already very high fire danger will
likely result in elevated to locally critical fire weather
conditions. A Fire Weather Watch has been issued for Mon for areas
east of Phoenix. Winds otherwise will be fairly light and follow
typical diurnal trends with afternoon breezes.
&&
.CLIMATE...
Daily Record Temperatures:
Phoenix Yuma El Centro
Saturday: 114 (1918) 115 (1956) 113 (1939)
Sunday: 112 (2019) 117 (1956) 115 (2019)
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Sunday for AZZ530>556-
559>562.
Fire Weather Watch from Monday morning through Monday evening
for AZZ133.
Heat Advisory until 8 PM MST this evening for AZZ557-558.
CA...Excessive Heat Warning until 8 PM PDT Sunday for CAZ561>570.
&&
$$
Visit us on Facebook, Twitter, and at weather.gov/phoenix
DISCUSSION...Sawtelle
AVIATION...Percha/Smith
FIRE WEATHER...Sawtelle/Benedict
CLIMATE...Kuhlman