Special Weather Statement, NWS Amarillo, TX

Area Forecast Discussion
National Weather Service Amarillo TX
621 PM CDT Wed Aug 21 2019

.AVIATION...
VFR with predominately VCTS weather conditions will be predominant
throughout the 00Z TAF period. Scattered thunderstorms have
impacted some TAF sites already this afternoon and may impact all
TAF sites through the overnight hours. A small break in
thunderstorm activity between 12Z and 18Z Thursday before VCTS
conditions return through to the end of the TAF period. With the
exception of chaotic winds within a thunderstorms, winds overall
will be out the south to southwest at 5-15 kts.

Meccariello

&&

.PREV DISCUSSION... /Issued 403 PM CDT Wed Aug 21 2019/

SHORT TERM...This Afternoon through Thursday Morning.
Several factors will influence the Panhandles weather over the next
24 hours or so. The main story is the increased chance for thunderstorms
especially for the Oklahoma Panhandle. On the synoptic scale, general
ridging continues over the southern Rocky Mountains with a downstream
trough over the Ohio Valley into Ontario and an upstream trough
over the Pacific Ocean just of the northwest coast. Several minor
shortwaves are showing up in the water vapor imagery near the ridge
axis, suggesting weaknesses in the over ridge pattern. The shortwave
over western CO/NM is promoting rapid convective initiation over
the Mountains as of 19z. Short and medium term raw models suggest
this feature will shift eastward through the evening helping to
increase mid/upper lift, especially for the northern half of the
FA between 00z and 12z. The main lift with the wave should then
start shifting east of the Panhandles after 12z Thursday.

A convectively augmented cold front is now stalling just north of
the Oklahoma Panhandle with upslope flow over most of western KS and
eastern CO. A lee surface low over far southwest KS with southwest
extending trough is noted in the surface observations with enhanced
Cu field from near Guymon to Clovis. A few thunderstorms are already
going in northwest OK along an outflow boundary ahead of the cold
front. This boundary extends into Beaver/Lipscomb Co. where
additional convective initiation is likely within the next hour.
These storms may help push outflow further south resulting in
additional convection, so have expanded pops south to include most
of the Texas Panhandle this afternoon. Storm coverage is also
expected to increase along the surface trough from near Guymon to
Clovis and near the weak surface low in southwest KS. Surface dew
points are generally in the mid to upper 50s, increasing near the
cold front along the KS/OK state line. This is where SBCAPE is in
the 1500 to 2000 J/kg range. South of the front, including most of
the Panhandles, SBCAPE of 500 to 1500 is expected (highest north
half and along the surface trough). DCAPE ranges from 1100 to 1500
J/kg with very high thunderstorm bases expected. Effective shear
will be low given weak kinematic environment. Moreover, scattered
thunderstorm activity this afternoon will mainly pose a wind threat,
with some rogue damaging wind gusts possible. The strongest storms
could produce some hail (low end severe can't be ruled out), mainly
in the higher CAPE region near the Oklahoma Panhandle.

Storm coverage is expected to continue to increase into the evening
and overnight hours as mid/upper level lift increases in response to
the approaching shortwave. Storms may take on a quasi-linear mode if
broad lift interacts with existing boundaries during the evening.
These storms will continue to pose a wind threat during the evening
but may lessen as storms become more elevated overnight. Hail will
be possible with the strongest storms given maintained elevated CAPE
with some cooling in the mid levels. Heavy rain will also be
possible given PWATs near 1.0 to 1.3 inches. Storm motion should be
10 to 20 knots, so flooding not a huge concern but can't be ruled
out with training storms. Activity should be on the decrease after
09z to 12z as lift with the shortwave begins shifting out of the
area.

Ward

LONG TERM...Thursday Afternoon through Wednesday.
The upper level ridge of high pressure will continue to broaden
with its axis south and west of the region through Friday night.
This will allow for minor upper level shortwave trofs embedded in
the overall flow pattern to track across the area Thursday through
Friday night. Also, the location of the upper level ridge axis
will cause the steering flow to be more favorable for bringing
showers and tstms into the forecast area from eastern New Mexico
and southeast Colorado in addition to development over the forecast
area. Utilized the model consensus blend approach for temps and
pops from Thursday afternoon through next Wednesday across the OK
and TX Panhandles. Most medium range models, including the consensus
blend, suggest a return to drier weather for this weekend into
Monday as the upper level ridge of high pressure moves closer to
the southern high plains once again. Pops then return to the
forecast area Monday night through Wednesday as the upper level
ridge axis retrogrades to the southwest states, placing the area
in northwest flow aloft. Also, most medium range models depict
some sort of cold frontal passage early to middle of next week.

02

&&

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

&&

29/15

Hazardous Weather Outlook
National Weather Service Amarillo TX
346 PM CDT Wed Aug 21 2019

OKZ001>003-TXZ001>020-317-221115-
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-
346 PM CDT Wed Aug 21 2019

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

.DAY ONE...This Afternoon and Tonight.

Thunderstorms are expected this afternoon and tonight across the
Oklahoma and Texas Panhandles. A few storms will have the potential
to become strong to severe with damaging winds the primary hazard.

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

Thunderstorms will be possible across the Oklahoma and Texas
Panhandles Thursday through Friday night, and then again Monday
night and Tuesday night. A few storms may become strong to severe
during these time periods, with damaging winds the primary hazard.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated at this time.

02

Special Weather Statement
National Weather Service Amarillo TX
602 PM CDT Wed Aug 21 2019

OKZ002-212330-
Texas OK-
602 PM CDT Wed Aug 21 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN TEXAS COUNTY UNTIL
630 PM CDT...

At 602 PM CDT, Doppler radar was tracking a strong thunderstorm over
Hough, or 13 miles north of Guymon, moving northeast at 20 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Hooker and Hough.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take shelter in a sturdy building if threatening weather approaches.

&&

LAT...LON 3681 10113 3673 10154 3692 10168 3700 10154
      3700 10106
TIME...MOT...LOC 2302Z 244DEG 17KT 3687 10155

LG

Special Weather Statement
National Weather Service Amarillo TX
623 PM CDT Wed Aug 21 2019

OKZ002-220000-
Texas OK-
623 PM CDT Wed Aug 21 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN TEXAS COUNTY UNTIL
700 PM CDT...

At 623 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Eva, or 14 miles southeast of Elkhart, moving northeast
at 15 mph.

Nickel size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Eva and Hough.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take shelter in a sturdy building if threatening weather approaches.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3684 10122 3661 10194 3694 10200 3699 10186
      3700 10127
TIME...MOT...LOC 2323Z 223DEG 13KT 3681 10177

LG

Special Weather Statement
National Weather Service Amarillo TX
626 PM CDT Wed Aug 21 2019

OKZ003-220000-
Beaver OK-
626 PM CDT Wed Aug 21 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN BEAVER COUNTY UNTIL
700 PM CDT...

At 626 PM CDT, Doppler radar was tracking a strong thunderstorm 5
miles northeast of Turpin, or 9 miles southeast of Liberal, moving
east at 15 mph.

Penny size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Beaver, Forgan, Mocane, Turpin and Floris.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take shelter in a sturdy building if threatening weather approaches.

&&

LAT...LON 3669 10039 3682 10093 3688 10095 3700 10094
      3700 10038
TIME...MOT...LOC 2326Z 286DEG 11KT 3693 10083

LG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
728 PM CDT WED AUG 21 2019

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

0714 PM     TSTM WND GST     2 W GUYMON              36.69N 101.51W
08/21/2019  M60 MPH          TEXAS              OK   ASOS

&&

EVENT NUMBER AMA1901102

LFM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
733 PM CDT WED AUG 21 2019

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

0720 PM     TSTM WND GST     2 E GOODWELL            36.60N 101.60W
08/21/2019  M59 MPH          TEXAS              OK   MESONET

&&

EVENT NUMBER AMA1901103

LFM

Special Weather Statement
National Weather Service Amarillo TX
821 PM CDT Wed Aug 21 2019

TXZ011-016-220215-
Deaf Smith TX-Oldham TX-
821 PM CDT Wed Aug 21 2019

...SIGNIFICANT WEATHER ADVISORY FOR OLDHAM AND NORTHERN DEAF SMITH
COUNTIES UNTIL 915 PM CDT...

At 821 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 10 miles northwest of Adrian to 10 miles
northwest of Bootleg. Movement was east at 20 mph.

Wind gusts of 50 to 55 mph will be possible with these storms.

Locations impacted include...
Vega, Adrian and Simms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take shelter in a sturdy building if threatening weather approaches.

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3558 10229 3491 10230 3487 10296 3540 10289
TIME...MOT...LOC 0121Z 250DEG 18KT 3535 10283 3496 10289

LG