Dust Devil in Texas, April 29, 2022

Area Forecast Discussion
National Weather Service Lubbock TX
237 PM CDT Fri Apr 29 2022

.SHORT TERM...
Hot, dry, and low-end windy conditions this afternoon will continue
into the early evening before winds relent with lower atmospheric
decoupling. This should begin around 7 pm, but may take until 9 pm
for decoupling with a zone of stronger flow from the northern South
Plains into the extreme southern Texas Panhandle. So, until then we
expect westerly wind mostly around 15 to 25 mph with strongest flow
again favoring the northern South Plains into the extreme southern
Panhandle. A surface low pressure center will move southeast later
today across the northern Texas Panhandle into the Red River area of
north Texas and a cold front will sweep across the area with winds
turning northerly mostly around 10 to maybe 20 mph. So a cooler late
night will follow with temperatures settling into the 40s on the
Caprock and mostly 50s across the Rolling Plains.

Saturday will see the atmosphere unwind behind the potent storm
moving into the northern plains. A low amplitude upper ridge will
approach from the west, and a cool surface high pressure ridge will
pass east through the Texas Panhandle. Northeast breezes will trend
southeast late in the day and high temperatures will range from
upper 70s to mid 80s, 10 to 15 degrees cooler than today. RMcqueen

.LONG TERM...
A closed mid/upper-level cyclone is forecast to rotate over the
Great Basin on Sunday morning, with a leading shortwave trough
ejecting east-northeastward over the west-central High Plains
region. While the mean flow aloft/above the boundary-layer will
become broadly cyclonic with the closed cyclone lagging behind
during the morning hours, mid- and high-level flow will begin to
increase as the aforementioned cyclone begins to transition into an
open wave and eject over the Four Corners by Sunday night. At the
surface, the mass fields will respond accordingly to the approaching
mid/upper-level cyclone and ejecting shortwave trough, with the
quasi-stationary front previously draped across the Permian Basin
and Edwards Plateau transitioning into a warm front and surging
northward across West Texas. As large-scale forcing for ascent
increases, the dryline will sharpen across east-central New Mexico
while remaining positioned west of the edge of the Mescalero
Escarpment on Sunday morning as lee cyclogenesis occurs in vicinity
of the Raton Mesa with backed, southeasterly surface winds retarding
eastward propagation. The arrival of a 700 mb trough on Sunday
morning in conjunction with the right-exit region of an approaching
mid-level jet streak and the onset of gradual geopotential height
falls will result in steepening lapse rates above the boundary-
layer, and therefore advecting an elevated mixed layer characterized
by MUCAPE values between 1,000-2,000 J/kg into the western zones by
sunrise. Inflow-layer parcel trajectories will be rooted above the
PBL top during the morning hours, with non-surface-based/elevated
convection possible as warm frontogenesis and the 700 mb trough
enhance moist, isentropic ascent particularly across the Caprock.
Shear vectors are forecast to already be oriented orthogonal to the
dryline during this time, with long hodographs above the PBL (where
shallow concavity will exist owing to the backed/southeasterly
surface winds), resulting in effective bulk wind differences (EBWDs)
and 0-6-km bulk shear magnitudes near 50 kt and 40 kt, respectively.
Large hail will be the primary hazard associated with the initial
wave of non-surface-based thunderstorms in the morning as the warm
front moves into the TX/OK PH region by the early afternoon hours
across the southern South and Rolling Plains.

Upon the onset of strong, diabatic heating, convective inhibition
(CINH) will decrease as the PBL depth deepens and mid-level lapse
rates steepen to near 7.5-8.0 deg C/km surmounted by backed surface
flow increasing to around 15-20 kt across the CWA as the lee cyclone
across northeastern New Mexico and southeastern Colorado deepens.
This will contribute to MLCAPE values increasing to 2,000-3,000 J/kg
by the early afternoon hours across areas west of the I-27 corridor
as T/Tds rise into the lower 80s and middle 50s, respectively; with
lower 30 mb mean dewpoints in the middle 50s as well, yielding mean
mixing ratios between 11-13 g/kg. Open moist sector initiation of
widely-scattered to scattered thunderstorms is forecast to occur by
the early afternoon hours across the Caprock and Rolling Plains with
the potential for destructive storm interference during the early
part of the convective stage as hodograph orientation remains
generally linear between 01/18Z through 02/00Z area-wide, resulting
in a multi-cellular storm character initially with splitting-cells.
The initial convective hazards as open moist sector initiation
occurs during the early afternoon hours will be large hail up to two
inches in diameter due to large, upward-directed accelerations
within the best-organized updrafts and as wet-bulb zero heights
descend to near or below 10,000 ft AGL. Damaging downdrafts up to 70
mph will be possible as well as the morning parcel trajectories
transition from being rooted above the PBL top to surface-based
(albeit high-based), with a fairly-mixed sub-cloud layer beneath
LCLs near 4,000-5,000 ft AGL. Convection is forecast to move
eastward throughout the afternoon hours with near-westerly mean wind
vectors near 30 kt, becoming more organized as supercell wind
profiles evolve towards the evening hours, especially across the
Rolling Plains.

The greatest potential for supercells will be east of the edge of
the Caprock escarpment as the low-level jet intensifies to 30-40 kt
in response to the opening mid/upper-level cyclone positioning over
the Four Corners on Sunday evening, with mid- and high-level flow
gradually veering as difluence increases aloft. The magnitude of the
backed surface-to-low-level flow will augment the influx of boundary-
layer moisture, with a plume of surface and lower 30 mb mean
dewpoints in the lower 60s advecting into the east and southeastern
Rolling Plains while also enlarging low-level hodograph concavity
near sunset. The magnitude of WAA combined with orthogonal shear
vectors will increase storm-relative helicity values between 100-300
J/kg across the Rolling Plains, with the potential for semi-discrete
supercells with the possibility of strong low- and mid-level
mesocyclones, and this development will be contingent upon the
convective morphology earlier in the day. Regardless, supercells
that materialize will be capable of producing potentially
significant-severe hazards with extremely large hail up to three
inches in diameter and localized convective wind gusts up to 80 mph
as precipitation-loading increases within the widest updrafts.
Tornadoes will be possible as well across the Rolling Plains,
especially within any supercell that becomes rightward propagating
and is able to ingest high theta-e inflow-layer air, and as LCLs
lowering considerably after dark. Convection should move east of the
CWA late Sunday night while also gradually weakening as CINH begins
to increase and surface flow veers.

The opening shortwave trough will eject over the central Great
Plains on Monday while becoming negatively-tilted, with the dryline
mixing east of the CWA. Vertical mixing heights are forecast to
ascend into the mid-levels behind the dryline, with temperatures
rising into the upper 80s and lower 90s from west-to-east. While
mixing heights will ascend into the mid-levels, the height gradient
will not be particularly tight as the core of the jet streaks remain
displaced far north of the CWA, with breezy, westerly winds expected
which will contribute to very low relative humidity. Critical fire
weather conditions will be possible on Monday area-wide. A cold
front will move through the region late Monday night into early
Tuesday as the shortwave trough de-amplifies and rotates towards the
Upper Midwest. By mid-week, global NWP guidance remains in agreement
with a closed low moving over the Great Basin and into the central
Rocky Mountains. The once-weakened cold front is forecast to move
transition into a warm front while moving north towards the KS/OK
border. Chances for thunderstorms, some severe, exist on Wednesday
into Thursday as the majority of the CWA will be within the moist
sector as the dryline anchors near the TX/NM state line. Potential
magnitude of severe-caliber hazards is not yet known, though details
will become better defined over the weekend into early next week.
PoP chances wane entirely by Friday into the weekend as the core of
the mid/upper-level cyclone moves eastward, with a weak cold front
intruding on Friday with benign weather to follow into the weekend
as low-amplitude ridging builds into the region.

Sincavage

&&

.FIRE WEATHER...
Critical fire weather conditions will continue late this afternoon
into the early evening before winds relax most areas near or a
little before dark. Strongest wind speeds late today should remain
from the northern South Plains into the southern Texas Panhandle.
Locally extreme fire danger should be expected where winds will be
sustained near 30 mph with humidities near 5 percent. The Red Flag
Warning thus will remain in effect until 9 pm. A cold front will
move southward into the area near or just after midnight, with
northerly winds briefly near 20 mph, but mostly settling around 10
to 15 mph. Cooler air will cover the area Saturday with light
easterly component breezes and lower fire danger. RMcQueen

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT this evening for TXZ021>044.

&&

05/09/05

Hazardous Weather Outlook...UPDATED
National Weather Service Lubbock TX
231 PM CDT Fri Apr 29 2022

TXZ021>044-301945-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-Floyd-
Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-Yoakum-
Terry-Lynn-Garza-Kent-Stonewall-
231 PM CDT Fri Apr 29 2022

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

.DAY ONE...This afternoon and tonight.

Critical fire weather conditions will occur across the region today
due to hot, breezy, and very dry conditions. Stronger westerly winds
could also result in reduced visibility due to blowing dust on the
Caprock. A Red Flag Warning is in effect for the extreme southern
Texas Panhandle, South Plains, and Rolling Plains until 9 PM CDT
this evening.

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

Elevated to critical fire weather conditions will be possible once
again on Saturday and Monday.

Thunderstorms will be possible on Sunday afternoon through Monday
morning as well as Wednesday afternoon across the entire region,
which will have the potential to become severe. Storms on Sunday will
be capable of producing very large hail, damaging winds, and locally
heavy rain, especially across the Rolling Plains.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.