Area Forecast Discussion
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FXUS64 KLUB 172349

Area Forecast Discussion
National Weather Service Lubbock TX
649 PM CDT Thu May 17 2018

From 00 UTC to around 03 or 04 UTC, scattered TSRA activity is
expected to impact KCDS, while outflow boundaries may affect KPVW
and KLBB, bringing periods of gusty winds and/or wind shifts. The
winds should gradually organize to the southeast overnight, then
come around to the south-southwest early Friday. VFR conditions
are expected on Friday aside from a small chance of TSRA in the
vicinity of KCDS after 18 UTC.


.PREV DISCUSSION... /issued 332 PM CDT Thu May 17 2018/

Initial convective development is occurring along the state line
within a zone of weak convergence along the surface
trough/dryline. The latest indications are that this activity will
progress pretty much closely previous projections, gradually growing
upscale with greater coverage as it progresses east. MLCAPE
values around 1500 to 2500 and deep-layer shear of 40 kts or so
are more than sufficient for sustained updrafts and a severe
wind/threat. A couple supercells are also possible as well with
the threat of very large hail.

The upper trough out west will move into the southern and central
Rockies Friday, with strengthening and veering mid-level taking
the dryline farther east during the day. The dryline is expected
to be located near the edge of the Caprock by peak heating and
scattered t-storm development will be possible in the Rolling
Plains, with more severe weather potential.

The trough swings northeast into the central plains Saturday while
the next trough digs quickly into the Great Basin. A cold front
will move south behind the first wave with a pretty good push to
it. There are still some timing differences between the guidance
with the front, and t-storm chances across the area will depend
highly on the front`s location by mid-afternoon. A shortwave will
be approaching West Texas late Saturday and could keep storm chances
going on through the night depending on how far south the front

By Sunday, the front should be well to our south, and we expect a
cool day and likely pretty stable, with low thunder chances.
However, in the face of strengthening southwest flow aloft as the
upper low stalls and deepens to the southwest, the front should
start to retreat pretty quickly back to the north and we could
see shower and t-storm activity pick up Sunday night in the
developing isentropic upglide regime. Thunderstorm chances should
continue Monday and Tuesday with the slow-moving upper low to the
west, and plentiful low-level moisture residing across the
region. Through this whole period, some pockets of heavy rainfall
are possible, as we could see several rounds of thunderstorm
activity track across similar areas.

The pattern may become less conducive for t-storm activity by
midweek as the upper low weakens with substantial energy racing
northward while broad troughiness lingers off the coast of
California. This could result in a building ridge over the
southern Rockies and West Texas.

Dry lightning is possible this afternoon across the western South
Plains where isolated to widely scattered thunderstorms are
expected to develop.

Fire weather concerns are expected on Friday to the west of the
dryline, which may be found near the edge of the Caprock by
afternoon. RH values across the western areas will fall to around
5 to 10 percent with wind speeds in the 15 to 25 mph range in the
afternoon. Recent rainfall in the southwest Texas Panhandle and
the possibility of rain this afternoon and evening create some
uncertainty regarding the extent of the threat.

Fire weather concerns are also possible Saturday afternoon across
western and southern portions of the South Plains in dry southwesterly
flow to the south of a cold front inbound from the north.




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