363
FXUS64 KLUB 302318
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
618 PM CDT Tue Apr 30 2024

...New AVIATION...

.SHORT TERM...
(This evening through Wednesday)
Issued at 150 PM CDT Tue Apr 30 2024

The dryline is nearing the I27/US87 corridor as of 130 PM and should
continue pushing eastward through the afternoon. A CU field is
beginning to develop across the Rolling Plains ahead of the dryline
where dewpoints are still in the mid to upper 60s. Models continue
to show isolated to widely scattered thunderstorms along the dryline
by 00Z, but confidence in storms developing within the boundaries of
the FA is dropping. Despite CAPE over 1200 J/kg and fairly steep mid-
level lapse rates, there is little in the way of upper lift
especially while the dryline is over the FA. Timing may line up for
a storm or two to develop over our far southeastern counties, but the
window of opportunity will be limited with storms more likely to
develop once the dryline is east of the FA. If a storm does develop
across our southeast, the main severe hazards will be golfball size
hail and wind gusts up to 70 mph.

Upper flow will become more southwesterly during the overnight hours
as the upper trough over the western CONUS amplifies. Surface flow
will become more southerly as weak surface low pushes from
northeastern New Mexico into the northern Texas Panhandle/Oklahoma
Panhandle and the dryline retreats westward. This will allow for
excellent surface dewpoint recovery with dewpoints rising back into
the upper 40s across our northwest and the upper 60s across our
southeast. This will help setup the potential for convection
tomorrow afternoon/evening. Models continue to develop convection
slightly westward with each run with initiation now being progged
along the dryline when it reaches the I27/US87 corridor to slightly
just west of there by 00Z. This happens as an upper level shortwave
trough moves over the region from northern Mexico.

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 150 PM CDT Tue Apr 30 2024

Convective activity is expected to become more widespread closer to
00Z or just after 00Z tomorrow afternoon. The severe threat will
peak around the same time. The same issues that will plague the
severe potential today will be similar into tomorrow evening.
Continued weak atmospheric flow will keep forcing weak or non-
existent. The atmosphere will have to rely on dryline convergence
and surface heating for convective initiation. Dry line convergence
does not look too impressive with more of a gradual dew point
gradient rather than a sharper gradient. Therefore low level winds
will depict weak veering along the dryline. Convection is expected
to be occurring at 00Z tomorrow afternoon. Surface dew point are
expected to remain in the upper 60s across the Rolling Plains by
late tomorrow afternoon with strong low level advection of moisture.
Strong heating will occur in the Rolling Plains into the upper 80s.
Very steep mid-level lapse rates between 8-9 C/km will promote mixed
layer instability values in excess of 4000 J/kg. Strong elevated
instability will continue to exist after sunset keeping the severe
threat going through much of the evening. Weak shear will likely
promote multicellular structure to convection with low chances of
supercells. Not much training of storms is expected but precipitable
water values around 150-175 percent of normal may promote isolated
heavy rain/flooding chances.

The dryline will race back to New Mexico overnight into early
Thursday morning with a drastic change expected from Thursday
through the weekend. A cold front will move southward through West
Texas during the day on Thursday. This front will bring cloudy and
cool conditions on Thursday. Strong low level moisture advection and
surface heating ahead of the front will lead to convection along the
leading edge of the front and dryline. However, the front may clear
the area by late in the afternoon shoving storm chances out of the
FA. Cooler than seasonal average conditions will persist through the
weekend under easterly low level flow. Although surface conditions
will be relatively cool and stable, warm air advection aloft will
generate instability aloft and continued chances of thunderstorms,
especially on Saturday. A short wave will approach the area on
Saturday bringing more widespread rain chances from Saturday evening
through Sunday morning.

&&

.AVIATION...
(00Z TAFS)
Issued at 608 PM CDT Tue Apr 30 2024

Isolated storms this evening will remain south and east of the
TAF sites. Winds about 800 ft AGL will increase late tonight
leading to LLWS at all sites through around sunrise tomorrow
morning. Also around sunrise tomorrow morning a slug of low-level
moisture will be working northward towards KLBB and KPVW which may
have MFVR to IFR ceilings associated with it. There is currently a
20%-30% chance of low ceilings impacting these sites for a few
hours tomorrow morning. Surface winds will increase by late
morning with sustained southerly winds around 15kts and gusts to
25 kts. The other concern for tomorrow will be the chance for
thunderstorms at the TAF sites towards the end of this TAF period
although confidence in timing and location of the storms remains
too low at this time to include a prevailing mention.

&&

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

$$

SHORT TERM...51
LONG TERM....01
AVIATION...58