724 
FXUS64 KLUB 250533
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
1233 AM CDT Tue May 25 2021

.AVIATION...
Thunderstorms were ongoing at all TAF sites early this Tuesday
morning and will persist for another hour or so at KLBB and KPVW
before finally moving east. Some rogue lightning may come close to
KCDS within the next few hours as well. Later in the morning, low
CIGS in MVFR category may return to all TAF sites but it is
unclear on whether this will occur or not. Isolated thunderstorms
will be possible Tuesday afternoon and evening at all TAF sites
again. However, coverage is expected to be much lower than what
was seen the previous day so no mention of thunder was made in the
TAF for Tuesday afternoon.

&&

PREV DISCUSSION... /issued 241 PM CDT Mon May 24 2021/ 

SHORT TERM...
An active weather period is expected this evening and tonight as 
thunderstorms, some severe, are projected to impact much of the CWA. 
Synoptically, the area remains situated between an upper low 
centered over Saskatchewan and an upper ridge over the Tennessee 
Valley. Consequently, southwesterly flow is present above 700 mb, 
with southeasterly low level flow courtesy of a weak lee cyclone to 
our west and broad surface high pressure to our east over the Deep 
South. The dryline is currently positioned over eastern NM, with 
southwesterly surface winds behind it. An impressive reservoir of 
moisture has built up in the low levels east of the dryline thanks 
to several days of southeasterly surface flow and persistent 
moisture advection. West Texas Mesonet observations place surface 
dewpoints in the low to mid 60s across much of the region this 
afternoon. 12z PWATs of 1.03" and 0.87" were sampled at MAF and AMA, 
respectively, this morning, and are expected to increase this 
afternoon. FWD sampled a PWAT of 1.80" at 12z, indicating the deep 
moisture present in our vicinity. Analysis of water vapor imagery 
depicts respectable moisture wrapping around the western edge of the 
upper ridge, with a shortwave and associated lift visible rotating 
through the higher terrain of northern Mexico.

Skies have cleared along and west of I-27/US-87, and temperatures 
have already warmed into the low 80s. Forecast soundings for this 
afternoon depict a very unstable atmosphere, with upwards of 2000 
J/kg of CAPE nearly universal in our region. SPC mesoanalysis even 
shows an area of >3000 J/kg CAPE edging into our southern counties 
where heating and moisture have been most robust thus far. Another 
notable feature about this setup is that there is very little 
convective inhibition present. However, upper level flow remains 
weak in magnitude overall, with 0-6 km shear barely reaching 25 kt. 
Nevertheless, given the deep moisture in place combined with the 
approaching upper level energy, the environment is still highly 
supportive of severe thunderstorms over the CWA this evening and 
tonight.

Late this afternoon, convection is expected to fire in eastern NM in 
the vicinity of the dryline where surface convergence magnitudes are 
largest. These storms may initially be discrete in nature, and given 
the ample instability, severe hail is possible across the western 
South Plains and southwest Panhandle late this afternoon. With time, 
this activity is expected to merge into a more coherent line and 
propagate eastward, becoming more cold-pool driven as it progresses 
through the central South Plains late this evening and into the 
Rolling Plains tonight. The threat for significant damaging wind 
gusts near 70 mph will exist with these storms, along with heavy 
rainfall and the potential for flooding given the current moisture 
levels. Storms will exit the area to the east early Tuesday morning.

West Texas will remain under southwesterly flow aloft on Tuesday, 
with weak embedded impulses transiting overhead. At the surface, the 
dryline is expected to mix further east, with southeasterly winds 
and dewpoints in the upper 50s to low 60s persisting east of the 
dryline. This sets the stage for another day of possible convection 
and severe weather in the vicinity of the dryline, though the 
details will be highly dependent on the evolution of the overnight 
convection. /DWK

LONG TERM...
Overall things continue to look active through the next week with 
convective chances possible most days. Convection should be pushing 
to the east of the FA by early tomorrow evening as upper riding 
moves overhead. This will be followed by southwesterly flow aloft 
Wednesday. Some convection is possible Wednesday afternoon and 
evening as the upper flow remains divergent, but the main limiting 
factor will be an overall lack of surface forcing as the dryline 
remains mostly to our west. Despite this some convection will still 
be possible especially if there are any remnant surface boundaries 
across the FA. By Thursday a weak front associated with an upper 
level shortwave moving across the northern CONUS will approach the 
region by likely not make it (mostly) through. The front will likely 
aid in developing convection across the region by Thursday evening. 
Another spot for convective development Thursday will be a dryline 
across the western half of the FA. Models begin to diverge with the 
upper pattern by Friday with the GFS keeping things mostly quiet 
under an upper ridge and with the ECMWF keeping mostly zonal flow 
with some embedded shortwaves producing convection. By Saturday both 
models have an upper ridge over the region with dryline convection 
pushing through Saturday evening/night.

&&

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

$$

01