Wildfire in Oklahoma, December 15 to 22, 2021

Area Forecast Discussion
National Weather Service Amarillo TX
535 AM CST Wed Dec 15 2021

.AVIATION...12z TAF Cycle...

Increasing low level moisture has produced stratus just south of
KAMA this morning. These could clip KAMA in the next hour or two
resulting in a brief stint of MVFR or even IFR conditions. Some
MVFR fog/drizzle is also possible, but more favored southeast of
KAMA. Confidence in any MVFR/IFR is too low to include in TAF at
this time. Will amend TAF as needed. Otherwise, strong low level
wind shear will be present for most of the morning at all
terminals. Southwest winds will start gusting around 15z, and
become very strong between 15z and 18z with gusts in the 50 to 60
knot range possible through about 22z. Winds will come down
sharply late afternoon such that gusts should be concluding by 00z
or so. Winds will shift to a northerly direction between 04z and
10z tonight behind a weak front.

Ward

&&

.PREV DISCUSSION... /Issued 402 AM CST Wed Dec 15 2021/

SHORT TERM...Today and Tonight...

Key Points:

--A highly anomalous, potentially damaging wind event is likely today,
  especially in the northern half of the combined Panhandles where
  wind gusts may approach historic levels for the month of
  December.

--Even a conservative forecast would include winds gusting over 60 mph
  today, with values over 70mph or even 80mph not outside the
  realm of possibility, especially near KGUY and KDHT.

--Based on the current timing of the system, the strongest winds
  should occur between 10 AM and about 3 PM before gradually
  decreasing into early evening.

--These winds will result in blowing dust, with visibility
  dropping to near zero at times. Motorists should exercise
  extreme caution.

--Extremely critical fire weather is expected today, with the
  northeastern CWA being most favored. Fire ignitions may occur due
  to downed power lines and spread rapidly. Folks should have an
  evacuation plan.

Details: A potent 500mb trough is speeding across portions of NV,
AZ, and UT. As of 0300z, WV imagery shows a very strong mid level
jet max moving into western NM. The most recent 00z RAOBs from
NKX, VEF, and FGZ indicated ~100kt winds at 500mb, and around 60
to 70 knot winds at 700mb. The latest model guidance suggest this
compact system will strengthen further as it moves over the
southern Rocky Mountains, possibly closing off over eastern CO
around 18z today. At that point, most raw models indicate a 115 to
130 knot jet max at 500mb extending across portions of northeast
NM, the northern Panhandles, and southwestern KS. The height
gradient becomes very steep from 850mb through 500mb, and the
progged wind profiles at KGUY, KDHT and KPYX are very impressive
from about 16z through 20z, with PBL top winds as high as 70 to 85
knots in the more agressive model sounding profiles (over 60 knot
average PBL layer winds). This suggests wind gusts could approach
65 to 75 mph or even higher. NBM 50th percentile 24 hour max
winds still support this idea, and statistical guidance is also on
board. All EC ensemble members produce 60+ knot winds. Thus,
forecast confidence is high.

Strong lee surface cyclogenesis will also occur over the Front
Range of Colorado, with a 982 mb low progged to move into NE by
18z. The Panhandles will be on the southern fringes of the
stronger isallobaric pressure falls, but still enough for
sustained wind enhancement. Mixing processes allowing momentum
transfer from the very strong winds aloft will be the main driver
for potentially damaging winds today. Have thus upgraded the High
Wind Watch over to a High Wind Warning for all of the watch area
except for Wheeler County, which was upgraded to a Wind Advisory
as it will be a bit too far removed from the stronger jet streak
at 700mb and 500mb. Donley and Collingsworth County were also
added to the Wind Advisory.

Winds will start coming down after 21z as the upper level low very
quickly shifts to the northeast. Most guidance has the H5 low over
northeast NE by 00z Thursday, with jets also moving out of the
Panhandle region by that time as the height gradients relax. A
weak cold front will moves through the Panhandles between roughly
03z and 09z, switching winds to the north northeast at 10 to 15
mph.

Ward

FIRE WEATHER...Today...

Today is shaping up to be particularly concerning with a SGPWO
composite situation unfolding. A highly anomalous speed max aloft
will intersect the western edge of a LLTR by late this morning as
very dry air mixes east. The primary intersection for our area
will occur in the northeastern combined Panhandles, and this is
where RFTI values of 7 to 8 are likely with the best overlap of 40
mph sustained twenty foot winds (gusts up to 65 mph) and min RH
values of around 8 to 10 percent. Fine fuels remain cured with ERC
values near the 95th percentile which suggests volatile ignition
potential. With 30 foot winds gusting as high as 65 to 75 mph
between 16z and 20z, there is a high probability that power lines
will be blow over and create sparks. Winds should decrease
considerably by 00z this evening, and a cold front will switch
winds to the north northeast between 03z and 09z overnight.

Given all of this, there are some limiting factors to consider as
well. First is the fact that we are quickly approaching the
winter solstice which is the shortest day of the year, so we are
not dealing with temperatures in the mid 80s like we do sometimes
with similar systems in March. Second is the fact that some areas
in the eastern Panhandles should see decent RH recovery this
morning. Some fog is even possible in the southeastern TX
Panhandle. This may help slow the receptiveness of the fuels for
ignition. Finally, thick blowing dust has helped limit max wind
gusts through reducing mixing potential, so while BD may create
it's own set of hazards, it can reduce wind speeds.

In any case, fire officials should be ready for a volatile and
very dangerous fire weather day today. A Red Flag Warning is in
effect from 9 AM to 6 PM across the Panhandles.

Ward

LONG TERM...Tomorrow through Tuesday...

Relatively uneventful extended forecast starting tomorrow through
early next week. Following the system today, a longwave trough
will swing across the intermountain west with the forecast area
under southwesterly flow aloft. Weak north winds and cooler air
will follow behind today's system with highs tomorrow expected to
be about 15 to 20 degrees cooler than today. However, these highs
tomorrow in the 50s will still be above normal for this time of
year. Winds will quickly recover to the south southwest tomorrow
as another weaker surface low forms in southeast Colorado. A weak
front will pass south across the Panhandles Thursday night into
Friday morning with little to no change in temperatures for
Friday.

By Saturday, the upper wave will will swing across the Upper
Plains with a cutoff low ejecting over Baja Cali. The passing of
the wave to the north of the area will drive cooler air into the
Panhandles with highs dropping into the upper 40s. The cutoff low
will then push northeast West Texas and north central Texas by
early next week with any chance for moisture associated with this
low remaining south of the area into central and eastern Texas.
Temperatures will continue to trend back into the 60s by early
next week, along with a continued dry pattern for the Panhandles.

Rutt

&&

.AMA Watches/Warnings/Advisories...
TX...High Wind Warning from 9 AM this morning to 6 PM CST this
     evening for the following zones: Armstrong...Carson...
     Dallam...Deaf Smith...Gray...Hansford...Hartley...
     Hemphill...Hutchinson...Lipscomb...Moore...Ochiltree...
     Oldham...Palo Duro Canyon...Potter...Randall...Roberts...
     Sherman.

     Red Flag Warning from 9 AM this morning to 6 PM CST this evening
     for the following zones: Armstrong...Carson...
     Collingsworth...Dallam...Deaf Smith...Donley...Gray...
     Hansford...Hartley...Hemphill...Hutchinson...Lipscomb...
     Moore...Ochiltree...Oldham...Palo Duro Canyon...Potter...
     Randall...Roberts...Sherman...Wheeler.

     Wind Advisory from 9 AM this morning to 6 PM CST this evening
     for the following zones: Collingsworth...Donley...Wheeler.

OK...High Wind Warning from 9 AM this morning to 6 PM CST this
     evening for the following zones: Beaver...Cimarron...Texas.

     Red Flag Warning from 9 AM this morning to 6 PM CST this evening
     for the following zones: Beaver...Cimarron...Texas.

&&

7/23

Hazardous Weather Outlook
National Weather Service Amarillo TX
409 AM CST Wed Dec 15 2021

OKZ001>003-TXZ001>020-317-152215-
Cimarron-Texas-Beaver-Dallam-Sherman-Hansford-Ochiltree-Lipscomb-
Hartley-Moore-Hutchinson-Roberts-Hemphill-Oldham-Potter-Carson-
Gray-Wheeler-Deaf Smith-Randall-Armstrong-Donley-Collingsworth-
Palo Duro Canyon-
409 AM CST Wed Dec 15 2021

This Hazardous Weather Outlook is for the Texas and Oklahoma
Panhandles.

.DAY ONE...Today and Tonight.

Critical to extremely critical fire weather conditions are likely
late this morning through the late afternoon across the
Panhandles.

Damaging winds are likely by late morning through the mid
afternoon hours across the Oklahoma Panhandle and a majority of
the Texas Panhandle. A High Warning is in effect for the northern
combined Panhandles and portions of the southern Texas Panhandle.
A Wind Advisory is in effect for the southeastern Texas Panhandle.

Blowing dust may create dangerous travel conditions due to low
visibility today.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated at this time.

Area fire managers and emergency officials should be alert for
critical to extremely critical fire weather conditions today.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
1032 AM CST WED DEC 15 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1020 AM     NON-TSTM WND DMG DALHART                 36.06N 102.52W
12/15/2021                   DALLAM             TX   TRAINED SPOTTER

            DAMAGE TO ROOFS AND TREES REPORTED IN
            DALHART. ASOS MEASURED 74 MPH GUST AROUND
            THAT TIME.

&&

MJG