Severe Thunderstorm Warning 144, NWS Lubbock, TX

Area Forecast Discussion
National Weather Service Lubbock TX
627 PM CDT Wed Jun 14 2017

.AVIATION...
Thunderstorms are likely to remain south and east of TAF sites
this evening, but can't completely rule out a few storms forming
along northward moving outflows mid to late evening. Should an
outflow develop, as we've seen the past two evenings, will update
to indicate the resulting winds, possible visibility reduction
from dust, and maybe an indication of nearby cumulonimbus. Until
then, however, modest low level southerly flow will dominate.
RMcQueen

&&

.PREV DISCUSSION... /issued 217 PM CDT Wed Jun 14 2017/

DISCUSSION...
Powered by a closed upper low moving northeastward into the
Prairie Provinces, a weak cold front has made its way through much
of the Texas Panhandle. It appears to have lost its impetus
entering mid-afternoon, and more important factors will come into
play for the forecast this evening. A surface trough or dryline
extends south of the front from near Memphis southwestward to near
Denver City. To the south and east of this trough lies a moisture
axis with a MLCAPE values of 2500-4000 J/kg and a weakening cap.
Short-term hi-res models have been consistently breaking out
thunderstorms on the western gradient of this moisture axis then
moving to the east-southeast with convective initiation by 5 pm.
Will nudge precip chances for the southeastern zones just into
chance category for the evening. Shear is weaker than yesterday
but remains adequate when combined with the amount of energy
available. Isolated supercells with the potential for large hail
remain possible.

The focus for storms shifts northward Thursday as the subtropical
upper ridge to our south begins to expand to the north. The
surface trough/dryline is expected to be the focus again with good
moisture remaining in place to its east. However, this appears to
be the last decent chance for precipitation in the forecast period
as the upper ridge expands further to north. The bulk of its
expansion will be to our west as the center of the ridge moves to
a position over AZ/NM this weekend, although there will be a
significant extension of the ridge eastward across Texas. Will
continue with temperatures well above normal and above the bulk of
numerical guidance, although of note is the move warmer in the 12Z
MOS values today. Sunday presents the possibility of
precipitation as a decently strong cold front undercuts the upper
ridge as a strong short wave trough moves across the northern
Plains. Current thinking suggests the ridge will hold firm enough
to suppress convection, but now with the models progging a
stronger front, the actual low level focus could shift to the
south of the forecast area late Sunday. Winds back to the
southeast on Monday which might provide another opportunity for
storms with a moist upslope flow, but the ridge still comes into
play. Will keep both days dry. Of more certainty is a cool down
for those days with forecast temps near seasonal norms. However,
with the ridge not showing signs of weakening or repositioning and
low level flow returning to south and southwest the heat will
likely return Tuesday.

&&

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

99/99/05

Hazardous Weather Outlook
National Weather Service Lubbock TX
1106 AM CDT Wed Jun 14 2017

TXZ021>044-151615-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-
Floyd-Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-
Yoakum-Terry-Lynn-Garza-Kent-Stonewall-
1106 AM CDT Wed Jun 14 2017

This Hazardous Weather Outlook is for the South Plains...Rolling
Plains and the far Southern Texas Panhandle.

.DAY ONE...This Afternoon and Tonight
A few thunderstorms may develop late this afternoon and early
evening mainly along and east of a line from Childress to Matador
and down to Tahoka. While the far majority of the region will
remain dry, there is potential for these few storms to produce
hail up to the size of golfballs and damaging wind gusts as high
as 70 mph.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday
Isolated to scattered thunderstorms will be possible again late
Thursday afternoon and evening along with additional risks of
large hail and damaging wind. Rain chances will then decrease
toward the weekend.

.SPOTTER INFORMATION STATEMENT...
Spotter activation may be needed mainly off the Caprock this
afternoon and evening.