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674
FXUS64 KLUB 231742
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
1242 PM CDT Sun Jul 23 2017

.AVIATION...
VFR conditions will prevail, however scattered t-storm activity
across the area this afternoon and evening could impact any of
the terminals and bring the threat of lightning, rain shafts with
low vsby, and strong, erratic wind gusts.

&&

.PREV DISCUSSION... /issued 1048 AM CDT Sun Jul 23 2017/

UPDATE...
Morning showers across the western South Plains have pretty much
come to an end - though some sprinkles are still possible across
Yoakum County. Water vapor imagery shows two MCVs in the region,
one in the Panhandle, and a stronger one to the south in the
Permian Basin. These features are currently nearly stationary so
they may not provide much convergence/lift for our area this
afternoon. The atmosphere remains very moist though and with
heating we should see at least widely scattered activity develop
this afternoon. Broad chance PoPs still appear to be valid area-
wide and we haven`t made any changes at this time.

PREV DISCUSSION... /issued 631 AM CDT Sun Jul 23 2017/

AVIATION...
VFR outside of TS. Slow-moving storms 50SW LBB at 630 AM should
decay in the coming hour or so, before random TS re-emerge this
afternoon. No reason to introduce blanket TEMPOs for thunder at
this time as forcing is too vague.

PREV DISCUSSION... /issued 401 AM CDT Sun Jul 23 2017/

DISCUSSION...
Thunderstorms continue across the forecast area this morning
although coverage and strength is slowly starting to wane. Upper-
air analysis shows good low and mid level moisture remains in
place across the area although water vapor satellite imagery shows
a few pockets of relatively drier air floating around the region.
Coverage of convection this afternoon will be driven by two
things; first is location of outflow boundaries from overnight
convection and second is how much heating will take place with the
remnant cloud cover from storms early this morning. Models all
generate between 500-1000 J/kg CAPE across the area but differ on
how strong cap strength will be. With differential heating
possible and outflow boundaries spread across the area, feel that
the potential for cap strength limiting the coverage will be low
but just enough to keep storms from going up all over the place.
Did increase PoPs a bit but kept them in the high-end chance
range. Temperatures will be a bit tricky as well thanks to the
cloud cover and outflow from overnight storms but we should be a
few degrees cooler than yesterday.

Models continue to flip back and forth with precipitation chances
for Monday and have now gone back to a wetter day than the past
couple of runs. Although the ridge does start to try and redevelop
through the day, heights do not increase as much as previously
modeled which may limit the amount of subsidence and as a result
limit cap strength. Models also keep a decent amount of mid-level
moisture trapped under the ridge which should also help to
provide at least one more day of isolated storms across the
forecast area. Have increased PoPs in the forecast for Monday
afternoon but removed them for Monday night as the loss of daytime
heating should quickly remove instability for storms, and
increasing ridge strength should keep any additional activity
from developing.

The ridge will remain over the area through at least mid-week but
models have now introduced a new wrinkle to the forecast starting
Thursday through the end of the forecast. A strong low will move
across southern Canada helping to dislodge a cold front mid-week.
This front is now forecast by both the GFS and ECMWF to push into
the northern Texas Panhandle by Thursday and then waffles back and
forth across the Panhandle through the upcoming weekend. At the
same time, the ridge will move a bit further west which will bring
northerly flow to the region and slightly lower heights. This is
the first run where all medium range models generate convection
each and every afternoon but keep the bulk of this across New
Mexico and the TX/OK Panhandles. Will have to wait and see if
storms will be able to help push the front further south but it
looks like Friday may be the day the front makes it into the
northern part of the forecast area. Temperature forecast for the
end of the week will be tricky due to the front but a slow
downward trend will bring temps back down to normal after running
above normal for the first part of the week.

Jordan

&&

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

$$

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