Drought in Texas, May 1 to 31, 2022

Area Forecast Discussion
National Weather Service Lubbock TX
651 PM CDT Sat Apr 30 2022

.AVIATION...
VFR and generally light winds will prevail this evening and tonight.
Winds will increase out of the southeast early Sunday morning with
a broken deck of low clouds expected to approach the region from
the south near sunrise. A period of MVFR ceilings is possible
through late morning at KLBB but confidence in the areal extent of
low cloud cover remains uncertain at this time. Mid-level
cloudiness will increase through the day at all sites with
strengthening southeast surface flow, and a few widely scattered
light showers will be possible through early afternoon as well.

Confidence is fairly high that convection will develop to the
west of the terminals on Sunday afternoon, moving eastward and
likely impacting the terminals Sunday evening. While this is just
beyond the scope of this TAF cycle, aviators should plan for
severe thunderstorms on Sunday evening. Very large hail along with
very strong and erratic winds will be possible at all terminals
late Sunday afternoon through Sunday night, with more specific
details on timing coming in subsequent TAF cycles. /DWK

&&

.PREV DISCUSSION... /issued 221 PM CDT Sat Apr 30 2022/

POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE EXPECTED
TOMORROW...

SHORT TERM...
A low amplitude upper level high pressure ridge axis will transition
slowly east across the area tonight. Surface high pressure credited
for today's cooler temperatures will edge east and low level
southeast flow will develop. A quiet weather night will follow.

Sunday morning will see a warm frontal boundary to our south lifting
fairly quickly northward in response to deepening surface low
pressure along the lee-side of the southern Rockies as vigorous
upper level low pressure rolls through the Great Basin. Dry air will
quickly give way to improving dewpoints and also deepening moisture,
and also could lead to a smattering of light showers Sunday morning,
maybe even a rumble of thunder with the lift over the warm front.
This possible shower activity Sunday morning is unlikely to cause
significant rainfall or stabilizing enough to impact late afternoon
developments. Meanwhile, a surface dryline will develop pretty far
west, probably along the Mescalero ridge just east of the Pecos
River, then mix east during the afternoon. This dryline should
remain near or west of the New Mexico border through the day Sunday,
but also appears capable of serving as a focus for thunderstorm
development by early to mid Sunday afternoon.

Storm generation Sunday afternoon will be most likely near the
dryline, but also could occur as mixing develops in the now warm and
moist low level southeast sector lying across the area. In addition,
solutions indicate a mid and upper level speed maximum crossing the
Texas Panhandle and northern South Plains that should add extra lift
and further weaken the already weak low level capping inversion.
Anyway, solutions are in fair agreement on a risk for severe
thunderstorms, somewhere between isolated and scattered, developing
by mid or late Sunday afternoon mainly across the western South
Plains, then spreading northeast at around 30 knots towards the
central South Plains and southern Texas Panhandle. Instability is
expected to be fairly high, with 2000 to 2500 Joules per Kilogram
along with around 40 knots or more of bulk shear. So we agree with
the Day 2 SPC Severe Weather Outlook indicating a risk for very
large hail, damaging wind, and even a conditional tornado threat
owing to healthy looping hodographs on the Caprock that may spread
into the Rolling Plains as storms trend east and perhaps upscale.
See more below. RMcQueen

LONG TERM...
Severe convection is expected to be ongoing Sunday evening/night
across the Caprock and Rolling Plains with generally an eastward
motion regardless if movement is governed by advection or
propagation. The low-level jet (LLJ) will begin to strengthen by
sunset to near 35-45 kt while remaining backed to the southeast to
south-southeast, enlarging hodograph concavity across the South
Plains and Rolling Plains with 0-1-km and 0-3-km mean storm-relative
helicity values increasing to near ~150 J/kg and ~300 J/kg,
respectively. Locally 300+ J/kg of SRH in the 0-3-km layer will be
possible amidst an influx of high theta-e inflow-layer air as mean
mixing ratios increase to near 14 g/kg owing to the magnitude of
backed surface/low-level storm-relative wind vectors. During this
time, anvil-level storm-relative flow will begin to weaken and veer
as the high-level jet streak moves northeastward into the central
Great Plains, which will have effects against entrainment magnitudes
and enhance precipitation-loading within updrafts as ventilation is
reduced. With anvil-level storm-relative winds decreasing below 40
kt late Sunday, classic to hybrid-HP supercells with strong low- and
mid-level mesocyclones will be possible with a very high threat of
producing extremely large hail up to three inches in diameter (e.g.
baseball size or slightly larger) in addition to damaging downdrafts
between 70-80 mph. If discrete, right-moving propagation is fully
realized then the risk for tornadoes will increase across the
southern Texas Panhandle into the majority of the South and Rolling
Plains after sunset. Exact mesoscale details during this time
will be contingent on how the convective morphology earlier in
the day pans out; however, confidence is high with scattered,
severe convection and related significant-severe hazards
persisting after dark across most of the CWA. Convection should
begin to clear the Rolling Plains near or after midnight, with the
possibility of cold pool mergers and upscale growth into a
Mesoscale Convective System beforehand as the LLJ veers.

The core of the mid/upper-level trough is forecast to eject over the
central Great Plains by Monday morning, with the dryline rapidly
mixing eastward and out of the CWA. Vertical mixing heights will
ascend into the mid-levels; however, downward momentum transport
speeds will be offset as the bulk of the more-amplified mid-level
flow remains displaced far north of the CWA. Therefore, only breezy,
westerly winds between 15-25 mph with locally higher gusts are
expected on Monday with temperatures ranging in the upper 80s to
lower 90s from west-to-east. Critical fire weather conditions will
develop during the afternoon hours due to the combination of breezy
winds, hot temperatures, and very low relative humidity. A cold
front will move in from the north overnight Monday into Tuesday,
with much cooler temperatures to follow on Tuesday as highs peak
generally in the middle-upper 70s to perhaps the lower 80s across
the southwestern South Plains with benign weather as a low-amplitude
ridge moves over the central CONUS. Global NWP guidance remains in
agreement with a potent mid/upper-level cyclone rotating over the
Great Basin and central Rocky Mountains by mid-week, with the
possibility of a triple point developing in the west-central Great
Plains which will ultimately dictate the position of the dryline,
which remains nebulous at this time. Therefore, broad PoPs were
maintained across the CWA with shear vectors supporting supercell
wind profiles on Wednesday. Another weakening cold front is forecast
to move through the region by early Thursday as the mid/upper-level
cyclone moves towards the Upper Midwest, with low-amplitude ridging
building behind with benign weather heading into next weekend.

Sincavage

&&

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

30/05/09

Hazardous Weather Outlook
National Weather Service Lubbock TX
658 PM CDT Sat Apr 30 2022

TXZ021>044-020000-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-Floyd-
Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-Yoakum-
Terry-Lynn-Garza-Kent-Stonewall-
658 PM CDT Sat Apr 30 2022

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

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The risk for severe thunderstorms will increase Sunday afternoon and
evening. A few severe thunderstorms are expected to form across the
western South Plains during the afternoon and then spread through
the eastern South Plains, southern Panhandle, and Rolling Plains by
Sunday evening. These thunderstorms will have the potential to
produce extremely large hail, damaging winds, and even a few
tornadoes. Locally heavy rainfall will also be possible.

Elevated to critical fire weather conditions are possible across the
region on Monday as hot, dry, and breezy weather returns to the
area.

Thunderstorms may return to portions of the area on Wednesday. Some
of these storms may become severe.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed on Sunday.