Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS64 KLUB 172339
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
539 PM CST Tue Jan 17 2017

.AVIATION...
Showers continue to increase and spread north toward terminals so
included them in prevailing conditions at onset. Initially kept
VFR conditions, though any heavier showers directly affecting
terminals will likely carry MVFR ceilings for a while. Main
degradation comes late this evening as stratus deck develops
during period of enhanced low level lift as shortwave passes to
the west. In the wake of the disturbance, sufficient subsidence is
noted with calm winds allowing favorable cooling for surface-
based fog to form. With reasonable confidence and agreement among
short range guidance have included IFR/LIFR cigs at KLBB around
sunrise with IFR at PVW and KCDS. Increasing southwesterly
component to wind should scour moisture by late morning.

&&

.PREV DISCUSSION... /issued 330 PM CST Tue Jan 17 2017/

SHORT TERM...

Low clouds across parts of the area cleared fairly fast this morning
only to be replaced by mid-level clouds increasing from the south,
mainly along and east of the Caprock.  Radar has been showing
reflectivity values increasing mainly just to the south of our area
of responsibility and West Texas Mesonet sites also show that the
only places seeing rain reaching the ground are in the areas of 45+
dBZ reflectivity.  Fairly dry boundary layer is preventing much of
the precipitation from reaching the ground outside of the heavier
areas of rainfall.  This current precip will help to moisten the
atmosphere up ahead of the next storm system which was located over
southern AZ/NM and was slowly moving east.  A shortwave will kick
out overnight tonight across the area which will help to further
increase coverage of precipitation across the area, roughly from
around sunset through the mid early-morning hours/before sunrise
Wednesday.  Models are starting to shift the area of greatest
coverage/intensity into the Rolling Plains but the NAM and GFS still
hint at another area of locally heavier precip near the TX/NM state
line.  Where the greatest amounts will fall will depend on how
strong the shortwave will be and where the best lift will move as
well.  Forecast soundings across the area show that there will also
be a narrow window where meager elevated instability will develop as
the shortwave helps cool the middle of the column. This combined
with the increasing lift may be enough to generate a few
thunderstorms mainly between sunset and roughly midnight to 1 am
before the shortwave is north of the area.  Lastly, surface
temperatures look to remain well above freezing during the
precipitation event so precip should remain liquid.

Once precipitation has shifted northward by sunrise Wednesday, there
could be enough clearing mainly across the southern South Plains to
allow temperatures to drop into the low to mid 30s but do not
anticipate any problems if temps fall below freezing in a few spots
due to short amount of time. The rest of the area will remain in the
upper 30s to lower 40s.  The main low will continue to slowly move
northeast with the center pushing into southeast Colorado by
Wednesday morning with a trailing, positively tilted trough
extending southwest into Mexico. This will result in southwesterly
flow aloft and at the surface which should help clear out any cloud
cover and precipitation by sunrise.  Only uncertainty is how much
high cloud cover may be pulled ahead of the trough axis and that
could impact high temperatures Wednesday afternoon a bit.

 Jordan

LONG TERM...

The first of several troughs to impact our region over the next week
will be lifting to the northwest into Oklahoma and Kansas on
Thursday. Dry air will rapidly work its way in thanks to strong
west/southwesterly winds, which will also help to boost highs that
afternoon. Winds that day will seem but a mild breeze compared to
the upcoming days, though. As shortwave ridging sweeps overhead
Thursday night, winds die down, but by Friday morning, the impacts
of the next upper level trough will be felt in the form of
increasing wind. This particular trough will swing by to our north,
pushing a tight pressure gradient across the region and bringing us
a Friday afternoon that could come close to wind advisory criteria.
As the progressive pattern continues, we`ll see our next trough the
very next day. This one may have the chance of bringing us
precipitation...along with more wind. The mid to upper levels look
fairly well saturated for Saturday afternoon and night, however,
with a dry surface and decent westerly winds, precipitation may be
fighting to make it to the ground. As this low deepens and moves
eastward, it will drag a cold front through on Sunday...with more
wind. Looking ahead to next week at the very end of the period, yet
one more low begins to swipe the region...and yes, with wind.

&&

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

$$

14/74/24


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.