858
FXUS64 KLUB 260241
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
941 PM CDT Fri Apr 25 2025

...New UPDATE, AVIATION...

.KEY MESSAGES...

 - Severe thunderstorms are expected across a majority of the
   forecast area through late tonight, with very large to giant
   hail, damaging winds, and tornadoes possible.

 - Multiple rounds of thunderstorms this evening through tonight
   will result in a risk for flash flooding, and a Flood Watch is
   in effect for a majority of the region through Saturday
   morning.

 - Daily chances for storms, some severe, continue through
   Wednesday.

&&

.UPDATE...
Issued at 912 PM CDT Fri Apr 25 2025

The tornado watch has been canceled across the extreme
southeastern Texas Panhandle and the northern Low Rolling Plains
due sufficient decoupling of the boundary layer and associated
decreasing boundary layer instability. Nevertheless, the potential
for elevated severe convection will likely persist for a few more
hours.

Elsewhere across the forecast area, convection, some severe, has
started to develop/expand in coverage as mid/upper level forcing
begins to imping from the west downstream from large scale
synoptic cyclone of the CA coast. Expect widespread showers and
storms across the forecast area through at least mid-day Saturday.

&&

.SHORT TERM...
(This evening through Saturday)
Issued at 207 PM CDT Fri Apr 25 2025

Forecast remains on track for a potentially widespread severe
weather event across our region this afternoon through late tonight.
Early afternoon water vapor channel imagery depicts a progressive
shortwave ridge axis transiting eastward overhead, with flow aloft
already starting to back more southwesterly over eastern New Mexico
downstream of broad mid/upper level troughing over the desert
southwest. At the surface, visible satellite imagery and mesonet
observations highlight a plethora of surface boundaries draped over
the region, with two of the most notable observed along a rough line
from Muleshoe to Plainview to Floydada, and another more diffuse
boundary hugging the edge of the Caprock Escarpment. Enhanced low
level confluence along these boundaries will serve as the initial
driver for convective development over the next couple of hours,
with towering cu already observed over northern portions of the
South Plains at 1830z.

Model soundings depict an essentially uncapped environment across a
majority of our region today, which combined with the already
observed strong surface heating and ample boundary layer moisture
(surface dewpoints as high as the upper 60s off the Caprock) will
result in a relatively early start to thunderstorm activity this
afternoon. These initial storms are expected to be mainly discrete,
with robust development fueled by MLCAPE values of 2000-3000 J/kg.
Hodographs begin relatively straight over a majority of the region,
pointing to splitting supercells capable of very large to giant hail
along with damaging wind gusts through the early evening hours. Of
note, the tornado potential is forecast to steadily increase through
the course of the evening in tandem with an increase in low level
shear as backed ESE surface flow continues to strengthen. At this
point, it appears that any cell that remains discrete will be
capable of producing a tornado, with the risk maximized in the
vicinity of the aforementioned surface boundaries. Of note, most hi-
res guidance is in fairly good agreement depicting a mainly discrete
storm more through early evening.

In general, we expect storm mode to transition to a more
multicellular form as the evening goes on. Large scale forcing for
ascent, while still relatively weak, is expected to increase near
and after sunset as modest midlevel height falls overspread the
region from the west in the wake of the departing shortwave ridge
axis. This should result in an overall expansion of storm coverage
heading into the evening, with multicellular storm mode and perhaps
a loosely organized MCS taking shape by late evening. A surface
front currently in the I-40 vicinity at 18z will shift southward and
looks likely to stall squarely over the South Plains region late
tonight. Combined with more coherent large scale forcing as well as
fairly strong southeasterly low level flow and positive theta-e
advection intersecting the front, this points to a potential of
several clusters of training thunderstorms overnight, with the
general threat tonight transitioning towards flash flooding. Given
the progged elongated instability profiles and PWATs running 200-
300% of climatological normals, flash flooding will be possible this
evening through late tonight with a Flood Watch consequently in
effect for a majority of the region until Saturday morning. Hi-res
ensemble guidance highlights a broad area of 1 to 3 inches of total
rainfall, with some localized areas of 4+ inches possible,
especially off the Caprock.

The expected continuation of thunderstorms through most of the
overnight results in a low confidence forecast for Saturday. The
convectively overturned atmosphere will likely struggle to recover
especially given morning low cloud cover, but with ensemble
consensus still pointing to the potential for additional
thunderstorm activity, will maintain the high blended PoPs through
most of Saturday for the time being.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 207 PM CDT Fri Apr 25 2025

Active weather will continue through next week although details will
be lacking until closer to each afternoon. Precipitation chances are
expected for most of next week with the greatest chances Tuesday
into Wednesday. Upper level pattern shows flow becoming
southwesterly as the ridging over head gets pushed east as a low
pressure tracks over the southern Rockies towards the Central Plains
on Sunday. Precipitation chances continue Sunday although, the
strong southwesterly aloft will lead to strong capping Sunday
afternoon preventing any convection development. By monday, models
show the upper low transitioning to a positively tilted trough with
the base over Baja California. this trough will aid in pushing a
Pacific front through the region overtaking the dryline that has
been lingering all week. Another cold front is progged to track
southward through the region Tuesday. The trough should slowly move
east through mid-week keeping southwesterly flow aloft. By the end
of the week, the trough should track across the Central Plains and
away from the region. ECMWF and GFS are in agreement with a Rex
Block setting up over the western CONUS by Thursday while another
front is progged to move through the region Friday. Temperatures
remain warm in the 80s to 90s for Sunday and Monday but will cool to
near or slightly above seasonal normal Tuesday through the rest of
the week.

&&

.AVIATION...
(00Z TAFS)
Issued at 912 PM CDT Fri Apr 25 2025

Potential for severe convection to specifically impact the KLBB,
KPVW, or KCDS terminals continues to decrease. However, SHRA,
perhaps TSRA, and IFR/low MVFR ceilings at all three terminals
will increase. Visibilities should remain predominately VFR, but
may drop into the MVFR category with the stronger convection.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Saturday morning for TXZ021>026-028>032-
034>038-041>044.

&&

$$

SHORT TERM...02
LONG TERM....10
AVIATION...02