389 
FXUS64 KLUB 051215 AAA
AFDLUB

Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
615 AM CST Wed Feb 5 2020

.UPDATE...
PoPs were slightly increased across the northwestern South Plains
and the western part of the extreme southern Texas Panhandle to 
account for the isolated light snow showers that will be possible 
over the next couple of hours. Little-to-no additional accumulations
are expected in these areas.

Sincavage

&&

.PREV DISCUSSION... /issued 549 AM CST Wed Feb 5 2020/ 

AVIATION...
Light snow will continue brushing near or over KLBB and KCDS
through much of the morning. Snow will be more difficult to 
impact KPVW. May be flirting at times with MVFR ceilings and 
visibilities for both KLBB and KCDS. Upper level low pressure 
trough will steer east of the area during the afternoon with 
clearing skies into the evening. RMcQueen

PREV DISCUSSION... /issued 341 AM CST Wed Feb 5 2020/ 

DISCUSSION...
Latest upper-level water vapor imagery indicates the base of
trough and associated shortwave digging into the Sonoran and
southwestern Chihuahuan Deserts. A baroclinic leaf was also
analyzed downstream of the vorticity maximum, now moving across
western and central Oklahoma. 

Mesoscale analysis indicates a belt of 650-500mb negative 
equivalent potential vorticity streaming across the southeastern 
and eastern Rolling Plains along the axis of mid-level 
frontogenetical forcing. RAP cross-sectional analyses also 
delineates a narrow theta-e corridor of weak symmetrical 
stability. This is all collocated with a fairly deep and saturated
(therefore supersaturated with respect to ice) planar crystal 
growth zone (PCGZ), favoring snowfall rates approaching 1" per 
hour along the far southeastern and eastern Rolling Plains. While 
this environment is not particularly favorable for slantwise 
instability, a couple of lightning strikes were observed further 
southwest in the Midland CWA. The forecast remains on track for 
the east/southeastern Rolling Plains and winter storm conditions 
are expected to persist through 00Z.

Towards the Lubbock vicinity: Snow accumulations have been fairly
light across the city and surrounding areas, with an increase in 
accumulations the farther east and southeast (as expected). The 
ice crystal growth regime is not favorable for aggregates and 
dendrites, evident by physical observation outside the office of 
tiny, plate-like crystalline structures. These types of ice
crystals are not sufficient for rapid accumulation and with less 
relative humidity within the PCGZ along the I-27 corridor, snow 
rates should remain very light throughout the remainder of the 
event. An additional 1-2 inches of snow will be possible for the 
Lubbock area and gradually trending lower the further west and 
northwest through late morning. Furthermore, the Winter Storm 
Warning has been cancelled for Bailey, Castro, and Parmer Counties
given the downward trend of precipitation.

Temperatures will remain quite cold today, with daytime highs
approaching the lower 30s across the CWA. A few scattered, light
snow showers will be possible in the afternoon given the residual
moisture layer aloft across the CWA before clearing out by 
tonight. Roads will remain very slick and icy long after the snow
ends with overnight lows dropping into the lower teens and wind 
chills near zero degrees. Expect impacts to regular travel once
again tonight due to the re-freezing of any meltwater. 

Relief from the brutal cold is forthcoming by the end of the week,
with a gradual warm-up expected as temperatures moderate into the
upper 40s and lower 50s across the CWA on Thursday. The work week
ends with welcoming in the 60s for high temperatures on Friday and 
remaining mild for the weekend.

Zonal flow returns for the extended period, with another longwave
trough forecast to pivot into the Desert Southwest bringing along
another chance for precipitation by the middle of next week across
the region.

Sincavage

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 PM CST this evening for TXZ023>026-
028>044.

&&

$$

09/05/09