Special Weather Statement, NWS Amarillo, TX

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
650 PM CDT Fri Sep 17 2021

.AVIATION...
For the 00Z TAFs, VFR conditions are expected at KGUY, KDHT, and
KAMA through late Saturday afternoon.

02

&&

.PREV DISCUSSION... /Issued 231 PM CDT Fri Sep 17 2021/

SHORT TERM (Today through tomorrow night)...

Overview:
The main story continues to be the cold front in the short term.
This has brought quite the gradient in temperatures across the
region. As of ~1pm, we have mid 60s in the northwest behind the
front, and low 90s in the southeast ahead of the front. The much
cooler temps in the northwest are partially due to low clouds in
the area. We are still expecting thunderstorms this afternoon
across eastern portions of the combined Panhandles as the front
advances farther south and east. Main concern will be damaging
wind gusts with any storms that happen to develop in the area.

Further Details:
This morning, 3 hour pressure changes were about 3-6 mb across our
northwest. This caused the front to easily push through most of
the Panhandles this morning/early afternoon. These pressure rises
have also resulted in a strong pressure gradient. Wind speeds
continue to be windy in the northwest where the wind advisory is
still in effect until 3pm. As the front continues to slide east
and south through the area, we will see our thunderstorm chances
increase later today/tonight across the warm/semi-buoyant sector
to the east. Mid level lapse rates (700mb - 500mb) this afternoon
may be around 7-8 C/km in the east, and this will result in MLCAPE
around 500-1500 J/kg with the absence of a cap across the east.
Thanks in part to large inverted-v forecast soundings, DCAPE
values may end up around 2000 J/kg. The weak effective shear
expected this afternoon and tonight will make hail a lesser
threat. We are expecting our main hazard to be damaging wind gusts
around 70 mph with any thunderstorms that happen to impact the
area today/tonight. While some hail will be possible, it will
likely be under an inch in diameter. There is some uncertainty
with thunderstorms this afternoon, and we may only get a few
isolated thunderstorms in the east. This has been the trend with
some of the HiRes models and convective allowing models. In other
words, widespread rainfall is not expected.

For tomorrow, temperatures will rebound back up above normal with
highs in the upper 80s to low 90s. There will also be plenty of
sunshines tomorrow as well.

Guerrero

LONG TERM...Sunday through Friday night...

By Sunday another upper level longwave trough will sit over
western Canada and the Pacific Northwest. The NAM and GFS suggest
that some showers and thunderstorms will be possible Sunday night
as the trough axis moves over the Inner Mountain West. The
perturbations in flow ahead of the trough that may possibly trigger
these showers and thunderstorms will most likely be isolated to
the Oklahoma Panhandle. With model disagreement and no real sign
of good moisture, as the best H7 theta-e is to the west and north
of the FA, have lowered the PoPs from the previous forecast. Will
leave a very slight chance in, but more around 5 to 10 PoP range.
There are too many GEFS members not showing any precip at this
time as well. The next best chance for showers will be on Monday
night with the help of frontogenesis. Have slight chance PoPs for
the Oklahoma Panhandle along and behind the next cold front.

Temperatures on Sunday will be well above normal in the 90s once
again, with the help of south to southwesterly winds and clear
skies. With this next upper level trough being more robust, better
CAA will take place across the northwest CONUS Monday and should
make it through the FA by Tuesday. This will leave a large
gradient in temperatures from the northwest combined Panhandles to
the southeast Texas Panhandle on Monday afternoon. Wellington
could see a high of 100 while Kenton, OK only gets to 85. Then on
Tuesday, daytime highs are only looking to be in the 70s with
maybe low 80s for areas off the Caprock to the south-southeast.
Temperatures will bounce back to the upper 80s to lower 90s by
Thursday before a slight cooling again there after. There are no
other real good signs at any beneficial rainfall in the extended
outside of the PoPs mentioned above.

36

&&

.AMA Watches/Warnings/Advisories...
TX...None.
OK...None.

&&

Hazardous Weather Outlook
National Weather Service Amarillo TX
322 PM CDT Fri Sep 17 2021

OKZ001>003-TXZ001>020-317-181130-
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-
322 PM CDT Fri Sep 17 2021

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

.DAY ONE...This Afternoon and Tonight.

Thunderstorms will be possible late this afternoon and this
evening across the eastern Texas and Oklahoma Panhandles. Strong
storms are possible, and a severe storm cannot be ruled out.
Damaging wind gusts will be the main concern.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Sporadic and isolated elevated Fire Weather may be possible
mainly over the Oklahoma Panhandle and the northwest Texas
Panhandle Monday through Thursday due to breezy and gusty winds
and low relative humidity.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated at this time.

Special Weather Statement
National Weather Service Amarillo TX
540 PM CDT Fri Sep 17 2021

TXZ015-020-172330-
Wheeler TX-Collingsworth TX-
540 PM CDT Fri Sep 17 2021

...A strong thunderstorm will impact portions of southeastern Wheeler
and northeastern Collingsworth Counties through 630 PM CDT...

At 539 PM CDT, Doppler radar was tracking a strong thunderstorm 6
miles west of Texola, or 8 miles east of Shamrock. This storm was
nearly stationary. Another storm was located 1 mile northwest of
Lutie. This storm was also nearly stationary.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Shamrock, Dozier, Lutie, Lela, Samnorwood and Twitty.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3498 10036 3508 10039 3540 10029 3539 10000
      3498 10000
TIME...MOT...LOC 2239Z 246DEG 2KT 3523 10010

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Ward

Special Weather Statement
National Weather Service Amarillo TX
604 PM CDT Fri Sep 17 2021

TXZ004-005-010-172345-
Hemphill TX-Ochiltree TX-Lipscomb TX-
604 PM CDT Fri Sep 17 2021

...A strong thunderstorm will impact portions of southwestern
Lipscomb, northwestern Hemphill and southeastern Ochiltree Counties
through 645 PM CDT...

At 603 PM CDT, Doppler radar was tracking a strong thunderstorm 11
miles southeast of Wolf Creek Park, or 13 miles southwest of
Lipscomb. This storm was nearly stationary.

HAZARD...Wind gusts of 50 to 55 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of southwestern
Lipscomb, northwestern Hemphill and southeastern Ochiltree Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Heavy rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3601 10050 3618 10059 3629 10041 3604 10027
TIME...MOT...LOC 2303Z 246DEG 1KT 3613 10047

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

Ward

Special Weather Statement
National Weather Service Amarillo TX
632 PM CDT Fri Sep 17 2021

TXZ020-180000-
Collingsworth TX-
632 PM CDT Fri Sep 17 2021

...A strong thunderstorm will impact portions of northern
Collingsworth County through 700 PM CDT...

At 632 PM CDT, Doppler radar was tracking a strong thunderstorm over
Samnorwood, or 11 miles south of Shamrock. This storm was nearly
stationary.

HAZARD...Wind gusts of 50 to 55 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Samnorwood, Dozier and Lutie.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Heavy rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3511 10010 3493 10017 3496 10043 3517 10031
TIME...MOT...LOC 2332Z 110DEG 1KT 3505 10025

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

Ward

Special Weather Statement
National Weather Service Amarillo TX
721 PM CDT Fri Sep 17 2021

TXZ010-015-180045-
Hemphill TX-Wheeler TX-
721 PM CDT Fri Sep 17 2021

...Strong thunderstorms will impact portions of central Wheeler and
southeastern Hemphill Counties through 745 PM CDT...

At 721 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles south of Canadian to 3 miles southeast
of New Mobeetie. Movement was southeast at 10 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Briscoe, Wheeler, New Mobeetie and Mobeetie.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3576 10006 3521 10030 3534 10044 3548 10050
      3589 10035
TIME...MOT...LOC 0021Z 333DEG 10KT 3578 10033 3551 10040

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Ward