Special Weather Statement, NWS Lubbock, TX

Area Forecast Discussion
National Weather Service Lubbock TX
710 PM CDT Fri May 28 2021

.AVIATION...
Watching a cluster of thunderstorms in eastern New Mexico slowly
move to the east. Confidence still remains low as to whether or
not this activity will reach KLBB or KPVW tonight. If it does hold
together than this activity would impact those terminals around
04z. Low ceilings will most likely return once again late tonight
into early Saturday morning with indications that these will hover
right around the MVFR/IFR height. Ceilings will gradually improve
late tomorrow morning with VFR conditions expected thereafter.

&&

.PREV DISCUSSION... /issued 225 PM CDT Fri May 28 2021/

SHORT TERM...
The big wrench thrown into the forecast today will be any remnant
outflow boundaries and front or fronts. The main quasi-stationary
front is well south of the region early this afternoon. This front
is expected to be the focus for the most intense convection of the
day in the Permian Basin and Big Country. Another weaker
boundary/front moved through earlier this morning and even another
boundary was currently moving southward through the southern South
Plains and southern Rolling Plains. Therefore, most convection has
been and will likely continue to be elevated through the evening.

A weak short wave seen on water vapor imagery, and to some extent in
models, was approaching the area across New Mexico this afternoon.
Combined with the upslope low level low, convection has already
begun in the Sacramento mountains of New Mexico. Nearly straight
line winds at 250mb will bring some broad and weak upper level
divergence overhead today. An area of higher theta-e air was
concentrated south of the main front in the Permian Basin. However,
a ridge of higher theta-e air extended northward into eastern New
Mexico. This will result in a very unstable air mass in this region
with MU CAPE values on the order of 2500-3000 J/kg near the
Texas/New Mexico state line. These instability values will decease
the farther east you travel into the South Plains. These instability
values along with fairly strong deep layer shear around 40-45kt will
support severe storms if updrafts can be sustained this far off of
the higher terrain of eastern New Mexico. Timing on these storms is
expected to be around mid-evening to reach the western and
southwestern South Plains. They will primarily have the potential to
produce large hail early on but likely transition to more of a wind
threat by late evening.

For Saturday, short wave ridging and rising heights will most likely
shut down convection for the South Plains. Additional development
off the mountains of New Mexico is likely but chances of these
storms making the South Plains is low.

LONG TERM...
Saturday night into Sunday, the shortwave ridge axis which provided
a brief reduction in precipitation chances during the day on
Saturday will shift east of the area. Mid to upper southwesterly
flow will quickly re-establish over West Texas as a digging 500mb
trough sweeps over southern Arizona on Sunday afternoon. Guidance
continues to indicate that this southern trough will phase with
another shortwave over south-central Canada, which should allow the
southern trough axis to retain a positive tilt as it slides
eastward. Ahead of this trough, low level flow will remain
southeasterly as broad surface ridging remains parked over the Ohio
Valley. Consequently, moisture will continue to stream into the area
on Sunday, with PWATs possibly approaching 1.3" (near the 90th
percentile of climatological values) and surface dewpoints reaching
the mid 60s across the CWA.

As the upper trough axis moves eastward on Sunday, a surface trough
will begin to deepen in the lee of the Rockies, and is progged to be
centered somewhere in the vicinity of the southern CO/KS border,
possibly further south into the OK Panhandle by Sunday evening. As
this occurs, a surface boundary will take shape and provide the
necessary convergence for convection to initiate. With ample upper
level support from 500mb height falls as well as an approaching
upper jet streak, a robust area of convection should develop in the
TX/OK Panhandles Sunday night and shift southward along the boundary
overnight into Monday morning. Given the magnitude of the moisture
present along with the amplifying effects of a strengthening low
level jet overnight, heavy rain and flooding will certainly be a
concern with this activity. Flooding concerns may also be elevated
due to slow storm motion and saturated ground from prior convection.
WPC has placed much of our area in a Slight Risk for excessive
rainfall Sunday into Monday, echoing these concerns.

The daytime hours on Monday also have the potential to be quite wet,
with additional rounds of heavy rain and convection possible as
residual boundaries linger around the CWA and the upper trough
remains to our west. Severe weather is also possible, as CAPE looks
to exceed 2000 J/kg and bulk shear looks to be around 40 kt. The
evolution of convection/heavy rain/severe weather will depend
heavily on the placement of boundaries and mesoscale features.
While these influences cannot be precisely resolved this far in
advance, confidence remains high that Sunday night into Monday
will be an extended period with impactful weather. Stay tuned as
the forecast is refined during the coming days.

Monday night into Tuesday, the axis heaviest rain will likely shift
to the southeast, although residual thunderstorms are possible
across the entire CWA on Tuesday and Wednesday as the upper trough
axis moves overhead. Temperatures will remain seasonally cool
through the middle of the week as well. By Thursday, the main trough
axis will be east of the area. However, broad cyclonic upper flow
will still be present over the southwestern CONUS and northern
Mexico. This combined with continued low level southerly to
southeasterly flow and subsequent moisture advection will result in
thunderstorm chances each afternoon through the end of the long term
period. /DWK

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&

58/01/30

Hazardous Weather Outlook
National Weather Service Lubbock TX
751 PM CDT Fri May 28 2021

TXZ021>044-300100-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-Floyd-
Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-Yoakum-
Terry-Lynn-Garza-Kent-Stonewall-
751 PM CDT Fri May 28 2021

This Hazardous Weather Outlook is for the South Plains, Rolling
Plains and the far Southern Texas Panhandle.

.DAY ONE...Tonight.

Scattered thunderstorms, some severe, will be possible this evening
across the western and central South Plains. Storms that do form will
have the potential to produce large hail up to two inches in
diameter and wind gusts to 75 mph. Also, heavy rain may lead to
localized flooding.

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

Thunderstorm chances Saturday afternoon and evening will be small
and confined to areas near the New Mexico state line. There is a
marginal risk that these storms could become severe. More widespread
showers and thunderstorms are expected Sunday and Monday and will
bring the potential for heavy rain and severe weather. Thunderstorm
chances will persist Tuesday and Wednesday and may again bring a
risk
for severe weather.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LUBBOCK TX
931 PM CDT FRI MAY 28 2021

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

0920 PM     TSTM WND GST     3 N PLAINS              33.23N 102.84W
05/28/2021  M58 MPH          YOAKUM             TX   MESONET

&&

EVENT NUMBER LUB2100376

WCI

Special Weather Statement
National Weather Service Lubbock TX
953 PM CDT Fri May 28 2021

TXZ028-029-034-035-039>041-290330-
Terry TX-Hockley TX-Lamb TX-Lynn TX-Lubbock TX-Hale TX-Yoakum TX-
953 PM CDT Fri May 28 2021

...SIGNIFICANT WEATHER ADVISORY FOR LUBBOCK...WESTERN LYNN...TERRY...
EASTERN HOCKLEY...SOUTHERN HALE...SOUTHEASTERN YOAKUM AND
SOUTHEASTERN LAMB COUNTIES UNTIL 1030 PM CDT...

At 952 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from Spade to 4 miles west of Reese Center to 6
miles southwest of Seagraves. Movement was east at 30 mph.

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

Locations impacted include...
Lubbock, Brownfield, Slaton, Abernathy, Tahoka, Wolfforth,
Shallowater, Idalou, Anton, Ransom Canyon, Cotton Center, New Moore,
Spade, Lubbock South Plains Mall, Locketville, Slide, Woodrow, Reese
Center, Lubbock International Airport and Texas Tech University.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
northwestern Texas.

LAT...LON 3296 10267 3362 10220 3402 10223 3401 10163
      3345 10159 3296 10197
TIME...MOT...LOC 0252Z 284DEG 28KT 3394 10213 3361 10211 3286 10264

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