003
FXUS64 KLUB 222331
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
631 PM CDT Thu May 22 2025

...New AVIATION...

.KEY MESSAGES...

 - Scattered-to-numerous thunderstorms, some severe, are expected
   along and east of the I-27 corridor this afternoon and
   evening.

 - Warming trend continues with daily chances for afternoon
   thunderstorms Friday through early next week.

&&

.SHORT TERM...
(This evening through Friday)
Issued at 1249 PM CDT Thu May 22 2025

17Z upper air analysis reveals a low-amplitude, shortwave ridge
shifting over the Rocky Mountains, with its slow, eastward
progression modulated by a cyclonic gyre over the northeastern U.S.
and Great Lakes region. Geopotential height tendencies were slightly
positive on the 12Z objectively analyzed upper air charts, with a
jet streak between 50-55 kt observed at 250 mb observed over W TX
and upstream of the CWA. Mid-level flow remained dampened due to the
amplitude of the shortwave ridge and phased, quasi-zonal state of
the synoptic-scale flow spread across the Lower 48, with about 25 kt
winds observed in the mid-levels over the Desert Southwest this past
morning. A corridor of high-level, moist, isentropic ascent was
detected on recent water-vapor imagery, and was beginning to emerge
over the southern Rocky Mountains as it translates through the
ridge. The 12Z RAOB from WFO MAF also observed a 40 kt low-level jet
that was nearly poleward, with recent LIDAR data from LBB observing
the now-dispersed low-level jet which remains veered slightly west
of due south, demarcating the western edge of the dryline.

At the surface, a quasi-stationary front was anchored between the
HWY-86 and HWY-70/62 corridors, with a weak surface cyclone located
near Northfield, and another ill-defined cyclone near Muleshoe,
resulting in double dryline structure across the CWA, albeit
diffuse. The eastern dryline extended southwestward from the low
towards LBB and into HOB, while the western dryline branched
southward along the HWY-214 corridor, and bending towards the
southwest and phasing with the eastern dryline circulation on recent
METAR and WTM data. Across the moist sector, a plume of middle-upper
60 degree dewpoints was evident on WTM data, with the 65 degree
isodrosotherm advecting northward along HWY-87 where surface winds
remain southerly. The baroclinity of the quasi-stationary front has
increased substantially compared to this morning, with a near-30 K
difference in theta-e on either side of the front. Sharpening of
this baroclinic gradient is a direct result of full insolation, and
the related differential vertical mixing, with diabatic heating
being offset by the cooler, northerly advection to its north while
the airmass continues to become weakly capped across the warm
sector. WTM data has also recently observed weak pressure falls from
the surface cyclone near Northfield, at around 1 mb/hr, but the
isallobaric response is expected to remain weak throughout the rest
of the afternoon due to the shortwave ridging aloft.

The airmass is expected to become uncapped entirely in the next 1-2
hours, with minimal LCL-LFC separation as convective temperatures
are reached. Scattered, multi-cellular thunderstorm development is
expected by 20-21Z, with straight hodographs governing several
episodes of splitting early on in the convective stage. The best
potential for a supercell or two will be along the quasi-stationary
front and eastern surface low near Northfield where the baroclinic
gradient is sharpest and juxtaposed to the plume of high dewpoints
despite the slightly veered component to the winds. Discrete to
perhaps semi-discrete propagation is expected along and to the
southeast of this quasi-stationary front, and will pose the highest
potential for very large hail up to golf ball size, in addition to
damaging downdraft gusts near 70 mph. A localized tornado threat may
materialize should the supercell(s) have enough longevity before
merging with the greater coverage of storms, and although LCL/LFCs
are high-based, storm-relative inflow near 20 kt may further enhance
the ingestion of low-level vertical vorticity, especially near the
triple point. Farther southwest along the dryline, counteracting
effects from outflow generated by too many storms will result in the
development of a loosely-organized line of multi-cellular clusters,
with embedded, mid-level mesocyclones posing a risk for large hail
and localized wind-damage. The amalgamation of cold pools will
continue throughout the afternoon and into the early evening hours,
with storms clearing the CWA near or shortly after dusk.

Heading into tonight, moistening of the low-levels will occur across
the Rolling Plains and onto portions of the Caprock, and will be
reinforced by residual, convective outflow from the complex of
storms. Winds were raised a few kt, with east-southeasterly winds
between 15-25 mph forecast to develop, which will result in the
development and advection of a low-level stratus deck across most of
the CWA tonight. Benign weather is expected otherwise tonight, with
the dryline retreating westward into NM. The quasi-stationary front
is forecast to remain anchored across the CWA tomorrow while the
dryline sloshes towards the TX/NM state line. Remnant outflow(s)
from convection today may still be intact by tomorrow afternoon, but
where exactly these boundaries stall is nebulous. Little change to
the airmass beneath the low-amplitude ridging will yield a similar
convective mode tomorrow, with intense heating expected as high
temperatures rise to near 100 degrees across the southern half of
the CWA. The orientation and magnitude of the deep-layer flow will
once again be favorable for mid-level rotation, with isolated to
perhaps widely-scattered storms developing by the early afternoon
across portions of the Caprock and Rolling Plains.

Sincavage

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 1249 PM CDT Thu May 22 2025

The weather through the weekend will continue to remain fairly
active under very hot temperatures. Large scale forcing for ascent
will be weak until late in the weekend when an upper level trough
approaches the area. Upper level flow will back more to the
southwest on Saturday as short wave ridging moves overhead and
amplifies which will also result in rising heights overhead.
Thickness values will continue to increase on Saturday boosting
temperatures into the very hot upper 90s to lower 100s. Hot
temperatures will lead to very deep boundary layer mixing up to
600mb or so. This will be enough to erode any cap that will be in
place bringing high based convection by late in the afternoon. Cloud
bases may easily be over 10kft under an unstable mid-level
atmosphere. Sunday will see increased uncertainty in the forecast as
a cold front encroaches on the area. At the same time, an upper
level trough axis will be crossing the four-corners region bringing
increased lift to the area from Sunday afternoon through Monday
morning. There is higher confidence in cooler temperatures returning
early next week as the front passes through the area by early
Monday. Upper ridging over the Intermountain West and low level
upslope flow may favor northwest flow convection during the second
half of next week.

&&

.AVIATION...
(00Z TAFS)
Issued at 624 PM CDT Thu May 22 2025

Winds will gradually shift from east to south overnight, before
becoming breezy out of the SSW at all sites by Friday afternoon.
VFR will continue through the early morning, before falling to
MVFR at all sites around sunrise. CIGs are expected to lift by
afternoon.

&&

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

$$

SHORT TERM...09
LONG TERM....01
AVIATION...19