Damaging Wind and Heavy Rain in Texas, July 16, 2017

Area Forecast Discussion
National Weather Service Lubbock TX
1200 PM CDT Sun Jul 16 2017

.AVIATION...
Combination of residual boundaries, rich deeper moisture, and a
weak upper disturbance will produce scattered showers and isolated
thunderstorms this afternoon and evening near all airports. Due
to time restrictions, have left prob30s out of tafs until 03z, but
will likely see some cells near terminals well before that, in
fact as early as 19-20z, with better coverage anticipated near
Lubbock and Plainview. Look for gusty winds to 35 knots and brief
downpours. Confidence in exact location will preclude mention
earlier in forecast. Outside of convective areas, VFR conditions
will prevail with fairly light winds.

&&

.PREV DISCUSSION... /issued 337 AM CDT Sun Jul 16 2017/

DISCUSSION...
A couple factors will result in better chances for showers and
t-storm activity across the forecast area today into tonight.
First, the upper ridging extending over the high plains has been
weakened by small upper-low over eastern Colorado, which coupled
with monsoonal moisture has produced persistent convective
activity in the central high plains the past few days. A weak
disturbance rotating around the upper ridge will carry some of this
moisture swwd out of Oklahoma and across West Texas today and
tonight. Precipitable water values which are already running 1.0
inches west to 1.5 inches east will increase to around 1.25 to
1.75. Secondly, an outflow-augmented front is moving across the
forecast area this morning. Although the temperature gradient and
wind field associated with the front are very weak, any small
upward push will help to get convection going in the weakly-
capped environment today. In fact, most of the convective-allowing
models favor convective development along the weak frontal zone
this afternoon, which is progged to run roughly from Swisher
County to Garza County (perhaps fortuitously located near the
Caprock Escarpment for an extra boost). CAPE values will be only
modestly improved from recent days, peaking around 500-1000 J/kg.
With very weak deep-layer shear, severe weather is not expected,
but some briefly strong updrafts could bring locally heavy
downpours and strong wind gusts. With easterly flow in the upper
trop, and very weak winds below, storms should favor a general
slow west-southwesterly motion, which will be modified at times
by outflow. Coverage of this activity still appears to be
scattered at best, and should gradually decrease after sunset,
although with the deep moisture we expect some activity could
linger on into the night.

The atmosphere will begin to dry out from east to west on Monday,
but this will be a slow process, and we certainly can't rule out
some isolated development Monday afternoon - although we'll keep
the forecast dry for now. Heights will rise across the forecast
area Tuesday into Wednesday as the upper ridge intensifies across
the central plains. An easterly wave present in previous runs of
the ECMWF now appears much more muted and heights are very
similar to the GFS for our area through midweek. The should
result should by very low rain chances and warmer temperatures,
climbing once again to near or slightly above the century mark in
the Rolling Plains after a slight cool down today and Monday.

The upper ridge will continue to build east until it settles over
the lower MS Vly by next weekend. Weak troughing will become
established across the southern Rockies and this should bring the
monsoon back into at least central NM after being shunted to the
southwest for a time. If the moisture plumes bends a little
farther to the east it could perhaps nick our west or northwest
Counties - something to watch for in the extended.

&&

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

06/99/99

Hazardous Weather Outlook
National Weather Service Lubbock TX
1127 AM CDT Sun Jul 16 2017

TXZ021>044-171630-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-
Floyd-Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-
Yoakum-Terry-Lynn-Garza-Kent-Stonewall-
1127 AM CDT Sun Jul 16 2017

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

.DAY ONE...This Afternoon and Tonight
Isolated to scattered thunderstorms are expected across the
outlook area this afternoon and evening. These storms will be
slow-moving and capable of producing locally heavy downpours,
strong downdraft winds, and dangerous lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

.SPOTTER INFORMATION STATEMENT...

The potential for hazardous weather is low.