Area Forecast Discussion
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FXUS64 KLUB 231518 AAA
AFDLUB

Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1018 AM CDT TUE AUG 23 2016

.UPDATE...
There is still some lingering uncertainty regarding the extent of
thunderstorm activity across the forecast area this afternoon. Per
the 12 UTC AMA and MAF soundings, our area resides in-between a
very tropical-looking airmass to our south and a more continental
airmass...with stronger deep-layer shear but also a more
formidable looking cap...in the Panhandles. Deep southwest flow
downstream of the vigorous upper wave in nrn Arizona should
continue to advect moisture into the area today, with 700 MB
analysis and water vapor imagery showing the western edge of the
moist plume cutting across our northwest counties, just to the
east of the surface trough over eastern NM. NWP QPF signals remain
somewhat divided over the coverage and intensity of precip this
afternoon, perhaps sensitive to the degree of capping and
instability development. The overall pattern suggests a good
potential for t-storms today and we have gone ahead and raised
PoPs for most of the forecast area, although not quite to the
likely range. Precipitable water values are running pretty high,
which could lead to some localized heavy rainfall if projected
CAPE values of 1000 to 2000 J/kg can be realized. However, with
the strong forcing expected to remain off to our northwest it
remains to be seen robust updrafts will be able to develop. the
stronger shear will be present across the far southwest Panhandle
into the northwest South Plains so that will be one area to watch
for some severe potential if we can get some discrete cells in
that area.

&&

.PREV DISCUSSION... /issued 545 AM CDT TUE AUG 23 2016/

AVIATION...
As the airmass is approaching saturation, we may see some fog
develop INVOF KLBB/KPVW around sunrise which may drop us into low
MVFR to possibly IFR category for an hour or two. There after VFR
is expected outside of convection. Scattered thunderstorm
activity is expected to form just west of KPVW/KLBB this
afternoon.

PREV DISCUSSION... /issued 438 AM CDT TUE AUG 23 2016/

SHORT TERM...

A low pressure system is located across southern
Saskatchewan this morning with a couple of waves rotating about
it. The first, of little consequence to us, is approaching the
Great Lakes with the next extending from srn WY into wrn Sonora.
The trough to our west is attempting to establish a closed
circulation. The trough axis will remain to our west today leaving
us southwesterly flow aloft. A jet axis will be placed from KTCS
to KDHT to KSLN this afternoon leaving us in the right entrance
region and thus providing a favorable lift regime.

Unfortunately southwesterly surface winds will bring in somewhat
drier air and help to limit coverage to some extent for much of the
day.  Into the evening hours, however, there are some hints that
winds will start to back just a little as the trough axis nudges a
bit closer.  Overall, the setup is far from a slam dunk for rainfall
so will highlight the corridor near the area of max theta-e this
afternoon and tonight for the best shot of rain.  With little shear
yet good instability, we may see a few storms pulse to become strong.

LONG TERM...

The cold front that models had been showing to move through and even
stall across the South Plains on Thursday now appears to be backing
off. The high pressure across the southeastern U.S. may be building
in slightly too strong, keeping the front from being able to make
its way very far south. Models now want to keep the front in the
northern to central TX Panhandle, though they do hint at a pre-
frontal trough of precipitation...much like we saw this past
weekend...moving through early Thursday morning. This would give the
entire FA a shot at showers/thunderstorms, but the cooler
temperatures and soaking rains do not look likely. We do at least
look to stay at or just below normal for highs through the extended.

We do keep slight chance PoPs in through the weekend as moisture
should continue to rotate around the southeastern high. By the
beginning of next week, though, we see a flattening of the ridge
with the start of the transition to a ridge over the south central
and southwestern U.S., effectively cutting off the monsoonal
moisture from our area.

&&

.LUB Watches/Warnings/Advisories...
None.
&&

$$

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