257
FXUS64 KLUB 280853
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
353 AM CDT Tue May 28 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Today and tonight)
Issued at 349 AM CDT Tue May 28 2024

As expected most of the morning convection has developed east of our
forecast area. The one exception has been over Childress county were
several convective attempts have been made with the activity
dissipating or shifting northward. Unfortunately, this morning
activity is leading to lower than normal confidence for the
remainder of the forecast today. As of 2:30 am, observations don`t
indicate a well defined cold pool has been generated near the Red
River quite yet. However as this convection continues to mature cold
pool generation is possible which would shift south today and leads
to the first big wildcard for today. This would shunt the warm front
farther south and cause high temperatures to be cooler than
currently forecasted. This warm front will also serve as another
forcing mechanism for thunderstorm development this afternoon so the
thunderstorm chances would have to be modified based on where it
settles. Otherwise, surface moisture continues to increase across
the forecast area with lower 60s being observed across the central
South Plains with lower 70s moving into the southern Rolling Plains
as of 2:30 am. Moisture will continue streaming into the forecast
area with the dryline remaining in eastern New Mexico through the
morning hours. Surface troughing across eastern New Mexico will
strengthen through the day this should allow southwest winds to
creep back into the western South Plains and shift the dryline just
east of the state line. Mixing on the Caprock should drop surface
dewpoints into the 50s by this afternoon and with sunny skies high
temperatures should climb into the mid to upper 90s while farther
east where the better moisture will remain temperatures will top out
in the upper 80s to lower 90s.

Forecast soundings show very little capping remaining by as early as
noon today but with limited upper-level support and the fairly high
bases (at least along the dryline) convective temperatures may need
to be reached before robust thunderstorm development occurs. The
environment will be characterized by MLCAPE values of 2500-3500 J/kg
along with 40 kts of effective bulk shear thanks primarily to
veering winds with height. This would support the potential for
supercellular development however with the nearly uncapped
environment numerous thunderstorms may end up developing leading to
more of a multicell cluster storm mode. If supercells can develop
then very large hail will be possible although the more widespread
hazard at this time appears to be damaging wind gusts. Inverted-V
profiles close to the dryline along with LCLs above the freezing
level indicate the potential for strong downdrafts. Thunderstorms
should eventually congeal into a line of storms as they move into the
better low-level moisture however that may not occur until they move
south/east of our forecast area. The other concern for primarily the
Rolling Plains (where the better moisture will remain) will be the
potential for locally heavy rainfall and the potential for flash
flooding as PWATs approach 2". This round of thunderstorms should
exit our forecast area by midnight however guidance indicates a
potential second round early tomorrow morning as convection from the
higher terrain of northeastern New Mexico eventually moves into the
far southeastern Texas Panhandle. Again based on all the
uncertainties involved with today`s forecast confidence on this
second round of storms remains low at this time. /WI


&&

.LONG TERM...
(Wednesday through Monday)
Issued at 349 AM CDT Tue May 28 2024

Early morning thunderstorms may be ongoing during the start of the
long-term period across portions of the southeastern Rolling Plains
Wednesday morning, before making a quick exit southward around day-
break. A very similar upper level pattern will remain locked in
place with the upper level ridge and a series of shortwaves moving
overhead of the region through the work week.

A disturbance in the flow aloft is expected to enter the region by
Wednesday afternoon which could potentially lead to thunderstorm
development across the FA, with the dryline expected to be
positioned somewhere across the South Plains. Although decent
moisture and a source of lift will be present there will be a few
things that will likely limit any kind of convection from developing
across our area Wednesday afternoon. One being an overworked
environment with not enough time for recovery as the overnight MCS
tracks southward along the theta-e gradient. Second being a very
stubborn low-level stratus deck overhead, limiting any kind of
diurnal destabilization through the afternoon. Therefore, chance
PoPs were lowered to slight chance across the FA. Expect
temperatures on Wednesday to be the coolest of the week in the mid
70s to low end 80s as the stubborn cloud deck remains overhead.

The upper level ridge will begin to shift eastward Thursday morning
with a series of perturbations following in its place. This will lead
to increasing thunderstorm chances once again on Thursday with
strong to severe thunderstorms not out of the question. Decent
moisture return is expected Thursday as low to mid level southerly
flow advects gulf moisture into the region, evident by a 700mb theta-
e ridge axis extending from the Gulf of mexico into the northern
Texas Panhandle. This in addition to the dryline positioned
somewhere across the South Plains will lead to increasing convective
potential on Thursday afternoon. Similar to previous days, the
environment will have to overcome the same caveats as Wednesday. If
low-level stratus decides to linger through the afternoon we may not
see enough diurnal destabilization to erode the CAP; in addition,
any kind of remaining outflow boundaries from previous convection
could throw a wrench in convective development. If thunderstorms are
able to develop an environment conducive of isolated strong to
severe thunderstorms will be possible with MLCAPE values above 4000
J/kg, steep low-level lapse rates, elongated hodographs, and bulk
shear above 40kts. Forecast soundings depicting long-skinny CAPE
profiles in addition to PWATs above the 99th percentile normal
around 1.5" suggests storms may pose a flash flood threat within
stronger storm cores.

Convective potential becomes a bit more messy and tricky into the
weekend with more perturbations in the flow aloft expected to track
in from the west through. Ensemble guidance continues to hint at
these perturbations keeping precipitation chances in the forecast
through the weekend. With all of the rain and cloud cover expected
temperatures through the period will remain slightly cooler in
the 80s to low 90s through Saturday, before a warming trend begins
to start the new week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1242 AM CDT Tue May 28 2024

Lower ceilings are developing around CDS this morning however they
should remain VFR until sunrise. Then there is a 10%-30% chance of
ceilings lowering into the MVFR range however this is highly
dependent on thunderstorm outflow across North Texas and western
Oklahoma. A dryline situated across the South Plains will lead to
thunderstorm development across the area this afternoon and
evening however with uncertainties regarding morning convection
the timing and location of the afternoon convection remains
uncertain. All terminals will have the potential to see
thunderstorm activity today though with gusty and erratic winds,
large hail, and visibility reductions due to heavy rainfall.
Easterly winds may also become gusty this afternoon and evening.

&&

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

$$

SHORT TERM...58
LONG TERM....12
AVIATION...58