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000
FXUS64 KLUB 202317
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
617 PM CDT Tue Apr 20 2021

.AVIATION...
Winds will continue to weaken this evening while veering easterly.
The wind will become southeasterly on Wednesday and increase
modestly during the afternoon. VFR will prevail, though a thin
cloud deck between 4,000 and 8,000 feet could affect the terminals
on Wednesday.

&&

.PREV DISCUSSION... /issued 306 PM CDT Tue Apr 20 2021/

SHORT TERM...

The surface pressure gradient has begun to ease behind the cold
front that pushed south across the region last night. Winds will
continue to gradually ease and veer more E/SE through the remainder
of this afternoon and evening. A Freeze Warning has been issued for
overnight, through 9am tomorrow morning due to light winds and
mostly clear skies aiding radiational cooling dropping temperatures
just below freezing for many locations across the South Plains,
Texas Panhandle and Rolling Plains. Short term model guidance has
continued to hint at the potential for increased midlevel
moisture/clouds across the South Plains and Rolling Plains that
might help some locations hold above freezing. West to northwest
flow aloft along with transient surface ridging from the Texas
Panhandle into western Oklahoma will keep temperatures in the 50s
tomorrow across much of the region.

LONG TERM...

A fairly progressive pattern will exist up across southern Canada
for the next few days.  This is not the case across the SWRN CONUS
where a split flow regime around a developing system across the
Great Basin will send a batch of energy eastward into the central
plains while a closed low attempts to develop across SRN CA. A low
over Nunavut will drop southward and attempt to phase with the
southwestern low Thursday night helping to kick it eastward and
traverse our part of the country on Friday. Behind Friday`s
system, mid-level flow will quickly return to a quasi-zonal regime
for the weekend becoming southwesterly Sunday night as another
trough digs into the west coast. Early next week, there is some
disagreement on the finer details between the GFS/ECM as to the
evolution/morphology of a passing shortwave with the GFS more
aggressively creating a negatively tilted trough as it passes
overhead. Will assume a blend until additional clarity is gained
over the next few days.

Return flow is expected to be in full swing Thursday evening as lee
troughing increases ahead of the California low/trough.  Given the
dry air in place down low to our east/southeast, it will take a bit
longer to get some workable moisture into the area for much more
than clouds.  Some stratus is expected Thursday morning but with
limited vertical extent and weak lift, not seeing much opportunity
for any meaningful precipitation though a few sprinkles may occur
east of the I27 corridor.  Despite increasing upper level support,
moisture levels look to keep most of the region dry as a strong
capping inversion keeps a lid on convection.  Friday will see strong
vertical mixing and perhaps a shot at a few virga showers east
during the afternoon though even that is questionable given the lack
of effective moisture where unstable conditions may lie.  Would
therefore expect to see storms form east of the CWFA where a more
favorable environment should exist.  Do want to assert that there is
still some opportunity for storms to fire in our far eastern zones
on Friday but the signal is just not sufficient to keep a real
mention at this time.  Drier air does work into the west on Friday
and the latest indications are we may be dealing with some fire
weather concerns across this part of the area.  A dry cold front is
expected Saturday morning.  Thanks to the nearly zonal flow, the
return flow will set up quite rapidly leading to warm advection once
again on Sunday.  Depending on how the next big trough ejects,
Monday or Tuesday could see another round of windy conditions with
perhaps our greatest fire weather concerns of this forecast
period.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from 1 AM to 9 AM CDT Wednesday for TXZ023>026-
028>044.

&&

$$

55/30/23