Severe Thunderstorm Warning 201, NWS Lubbock, TX

Area Forecast Discussion
National Weather Service Lubbock TX
630 PM CDT Thu May 23 2019

.AVIATION...
Thunderstorms are expected to impact KLBB for the next couple of
hours or so. They will bring strong and variable winds and
possibly reduce visbys with heavy rain. These same storms could
impact KPVW but chances are more uncertain due to the isolated
coverage of the storms. Chances of storms are even less at KCDS
but could impact KCDS around 06-10Z. Low CIGS may come back in to
all TAF sites after midnight and may persist until early
Friday afternoon.

&&

.PREV DISCUSSION... /issued 235 PM CDT Thu May 23 2019/

DISCUSSION...
Analysis of this afternoon's data continues to suggest the current
forecast is on track. We continue to see a risk of a few
thunderstorms developing across the far northern South Plains and
southwestern Texas Panhandle near a dryline bulge/triple point.

The upper low sub-core across northern AZ is still noted on WV
imagery and should arrive near the four corners later this
afternoon. This is a common position for late spring severe
weather in West Texas.

The cold front has dipped into Parmer and Castro county and become
stationary; it is set up near the US HWY 60 corridor. A cap
of 1-3C remains in place south of this boundary as evidenced by
AMDAR soundings out of KLBB. Convergence across the dryline is
quite weak at this time but the continued effects of diurnal
heating should get us close to convective temperatures out near
the TX/NM state line which is where the dryline has become better
established. The cumulus field continues to yield some instances
of towering Cu though the updrafts appear to be succumbing to the
cap. The longer that convection holds off, the more primed the
loaded gun will get with SBCape already in the 3-4kJ/kg. Winds
have started to back up in our northern zones in response to
pressure falls near the triple point INVOF Parmer county. This
portion of the CWFA is where our greatest tornado risk will likely
be with more of a hail/wind threat further down the dryline
though tornadoes will certainly be possible in locally enhanced
helicity near rotating cells. With little eastward movement of the
line, cell training may pose a flooding threat yet the signals
are mixed as to the sustainment and coverage of storms into the
evening and overnight hours. The synoptic and mesoscale patterns
and PWAT values do suggest a flooding potential if things can grow
upscale. Our flood watch is in effect until 11Z and we will
continue to reevaluate the evolution through the evening and
overnight hours as we may see a continuation of heavy rain into
Friday. For severe threats, baseball hail and 70 mph winds seem to
be fitting given the CAPE/shear balance and antecedent
environmental factors.

For the period Friday through Wednesday: Southwesterly flow
will persist over the region and much of the severe risk will
depend on the longevity of what activity precedes a given forecast
period. The current outlook suggest that areas west of I-27 will
see the most recurring risk of thunderstorm activity with ares
toward Aspermont perhaps receiving scant to no rainfall. A push of
the surface boundary now looks to occur on Monday though data
indicates a capped environment. The overall synoptic pattern
suggests that heavy rain could be a more pronounced threat than
severe though we will likely have windows of severe activity each
day. With such a dependence on previous-day's convection, we will
highlight the general mention of storms at this time and hit the
severe threat on a day by day basis.

Monday is a bit of a change from yesterday as the dryline surge was
previously progged to occur on Tuesday. However, this makes sense
if the models are correct in ejecting the southwestern UL low.
Things appear to be dry (consistently) on Tuesday with storm
chances on the increase later in the week once again.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 6 AM CDT Friday for TXZ022>026-028>031-033>036-
039>041.

&&

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