401
FXUS64 KLUB 031127
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
627 AM CDT Fri May 3 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 343 AM CDT Fri May 3 2024

Another round of strong to severe thunderstorms are possible this
afternoon and evening along and east of the dryline as the left exit
region of an 80 knot jet streak moves over West Texas (not
particularly strong for jet level winds but is probably aiding in
enhancing large scale lift). Low level moisture will continue to
advect into the forecast area which will maintain surface dewpoints
in the mid-60s in the Rolling Plains and southeast Texas Panhandle
and mainly in the 50s for areas on the Caprock which again will
prime the lower atmosphere for thunderstorms. Strong to severe
thunderstorms are likely to form along the dryline in the afternoon
and evening with forecast MLCAPE exceeding 3000 J/kg and deep layer
shear of about 40 knots in the moist sector supporting supercells
capable of very large hail. Forecast tornado parameters (low
level helicity) are not very impressive but a tornado cannot be
ruled out in a well organized supercell. CAMs suggest initial
discrete supercells which could produce very large hail and
damaging winds. If storms continue to form, they may congeal into
an MCS and begin to move east out of the forecast area.

3 AM satellite imagery shows patchy low level stratus across the
southwest Texas Panhandle and portions of the Rolling Plains. This
low level cloud cover is expected to continue to expand in
coverage this morning with the low level moisture advection.
Latest model guidance indicates these clouds will clear or become
patchy by the afternoon allowing surface temperatures to climb
into the 80s for these areas. However, if stratus hangs around
through the afternoon, thunderstorms may struggle to initiate.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 343 AM CDT Fri May 3 2024

The greatest forecast challenge in the long term remains a
potentially stronger and faster FROPA on Saturday morning which may
ultimately shift the heaviest rainfall farther south and southeast
of our domain by later in the day. Nevertheless, the overall
pattern by Saturday afternoon and evening remains favorable for
widespread measurable rain in the wake of a morning FROPA which
should slow or stall as it reaches the I20 corridor by the
afternoon. Moist E-NE sfc-850 mb flow following FROPA along with
an uptick in southerly moisture advection at 700 mb preceding a
shortwave trough later in the day will all help push PWATs to 0.5"
to 0.75" above normal. Given the abundant post-frontal stratus
and the front stalling to our south, NBM`s high temps were nudged
lower and closer to the more representative MOS. Despite this,
soundings still depict ECAPE around 1000 J/kg on average across
the southern half of the CWA which could spur at least a marginally
severe hail threat, although the greater threat remains heavy
rainfall given anomalously high PWATs and improving ascent from
the afternoon into the evening. Heavy rain probabilities are
almost always trickiest with cellular convective modes such as
this event as opposed to MCSs, so we won`t get too invested in
messaging 1" or greater rainfall probabilities particularly given
considerable spread still evident in the LREF`s QPF.

NBM`s PoPs were scaled 10-20% lower beginning late Saturday night
through the day on Sunday to account for stronger subsidence/height
rises behind the upper trough. This drying should eventually
secure some sunshine by Sunday, although lingering moist upslope
flow will undoubtedly delay this process until later in the day
and curb high temps. Deeper drying and windier conditions unfold
on Monday as a vigorous upper low turns negatively tilted to our
north and sweeps the dryline off the Caprock where some low PoPs
remain. Uneventful weather then sets up from Tuesday and beyond
south of a deamplifying upper trough, yet some re-amplification
to this trough from Wed-Thu looks to send us a healthy dose of
Canadian air with below-normal highs by the end of the week.

&&

.AVIATION...
(12Z TAFS)
Issued at 627 AM CDT Fri May 3 2024

Widespread IFR stratus with occasional LIFR decks should gradually
erode and give way to VFR by early afternoon at LBB and PVW as a
dryline draws closer. CDS meanwhile is unlikely to see any
improvement beyond MVFR in this very moist upslope pattern. Latest
signals for late day TS are now favoring areas SE of LBB, though
ISO TS will be possible along the extent of the dryline through
this evening.

&&

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

$$

SHORT TERM...17
LONG TERM....93
AVIATION...93