Flash Flooding and Flooding in Texas, May 24, 2019

Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1210 PM CDT Fri May 24 2019

.AVIATION...
MVFR to IFR conditions in place at KLBB/KPVW/KCDS but expect to
see gradual increase in ceiling heights to MVFR then VFR by late
this afternoon. Storms are already developing south of KLBB and
expect convection to spread towards other TAF sites through the
day. Gradually will see ceilings fall back into MVFR to IFR range
overnight tonight into Saturday morning at all three TAF sites
once storms dissipate.

Jordan

&&

.PREV DISCUSSION... /issued 1142 AM CDT Fri May 24 2019/

UPDATE...
Another day of potentially active weather is in store for this
afternoon and evening. Upper level flow does not appear like it
will hinder any convective development today. Although the upper
level jet streak will continue to be well out west of the area
near the four corners region, numerous models agree in depicting
weak upper level divergence spreading over the area early this
afternoon before convective initiation. Furthermore, height
changes will be nearly neutral for the rest of today.

Closer to the surface this morning, ongoing showers and isolated
thunderstorms have already almost completely dissipated near a
frontal boundary. This warm front has already begun to move back
northward although we are skeptical of how far north the models
move this front. Farther south, a dryline will continue to extend
on a north-south orientation around the Texas/New Mexico state
line, south into the Big Bend. Surface dew points remained around
70F off the caprock late this morning with southeasterly winds
already increasing to values on the order of 18-25kt. Higher
theta-e air at low levels will likely continue to surge northward
along the dryline and then northeastward along the frontal
boundary. Low clouds were scattering out late this morning from
south to north from the Permian Basin into the South Plains. This
trend is expected to continue into the Rolling Plains into the
afternoon hours. Otherwise, there should not be much in the way to
hinder any surface heating. Strong instability already exists
over the area evident by the cumulus field above the low cloud
layer. Capping does appear to be weaker today with 700mb
temperatures closer to 9-10C based on AMDAR soundings. Models show
this cap breaking by mid afternoon with mixed layer instability
values peaking around 3000 J/kg again. This will contribute to
another afternoon and evening of large hail potential. However,
the tornado threat is somewhat lesser today with less low level
helicity. The best chances of tornadoes will be closer to the
frontal boundary in the southeastern Texas Panhandle this evening
as the low level jet begins to increase. Furthermore, heavy rain
is likely again. Precipitable water values are extremely high with
upper flow parallel to surface boundaries.

PREV DISCUSSION... /issued 412 AM CDT Fri May 24 2019/

DISCUSSION...
Active pattern will continue to produce numerous rounds of
convection through the weekend into the beginning of next week.
The persistent troughing to the west will begin to sharpen and
deepen between now and Monday, while gulf moisture streams
northwest across our region.

The SPC has most of our forecast area in a Slight Risk for severe
storms this afternoon and evening. Conditional instability in the
form of a capping and confluent upper level flow may limit severe
potential across our forecast area, but certainly not eliminate it
altogether. Although the severe threat may be somewhat limited,
expect strong storms with large hail and wind gusts as the primary
threat.

The SPC keeps our CWA in a Slight Risk on Saturday, which seems
warranted given the current guidance. As the trough to our west
begins to deepen through the day tomorrow another closed low off
the Pacific Northwest will dive south along the West Coast. As the
closed low carves south across the West Coast, southwest H50 flow
between 40-50kts over our region will begin to open up and become
divergent as relatively potent shortwaves further destabilize the
mid and upper levels through the afternoon and evening hours.
While the upper levels gradually destabilize, ample surface
moisture, dryline and a meagher cap should all point toward the
potential for another day of significant severe weather in our
vicinity. Strong winds, large hail, tornadoes and flooding may all
be issues to contend with beginning in the middle of the
afternoon on Saturday. Sunday and Monday continue to show
opportunities for more severe storms as the SPC has highlighted.
All the ingredients will continue to be in place but the
potential and timing of atmospheric recovery may have significant
impacts on location and extent of severe storms. Given the
conditional threat today leading into tomorrows forecast,
confident that the atmosphere will have plenty of time to recover.
That confidence doesn't extend into Sunday and Monday.

&&

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

14/14/14

Hazardous Weather Outlook...UPDATED
National Weather Service Lubbock TX
1143 AM CDT Fri May 24 2019

TXZ021>044-250445-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-
Floyd-Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-
Yoakum-Terry-Lynn-Garza-Kent-Stonewall-
1143 AM CDT Fri May 24 2019

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

.DAY ONE...This Afternoon and Tonight

Strong to severe storms are possible this afternoon and evening
as a dryline positions itself along the US Highway 385 corridor.
Expect hail up to the size of tennis balls, strong wind gusts up
to 70 mph, and locally heavy rainfall that could result in
localized flooding with the strongest thunderstorm activity.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Daily chances for severe storms are expected Saturday through
Monday as an active pattern continues across much of the region.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be requested this afternoon through tonight
for much of the South Plains and Rolling Plains.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LUBBOCK TX
849 AM CDT FRI MAY 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0535 PM     HAIL             DIMMITT                 34.55N 102.32W
05/23/2019  E1.00 INCH       CASTRO             TX   CO-OP OBSERVER

&&

EVENT NUMBER LUB1900442

JDV