Dust Storm and High Wind in Texas, December 17, 2016

Area Forecast Discussion
National Weather Service Lubbock TX
1109 AM CST Sat Dec 17 2016

.AVIATION...
Low end MVFR cigs continue at CDS while PVW and LBB are
experiencing low end IFR cigs as a result of the frontal passage.
Cigs should rise to low end MVFR at PVW and LBB by the early to
mid afternoon, and cigs should turn VFR at all terminals by the
late evening. There is a possibility of frozen precipitation at
PVW and CDS during the afternoon and early evening. Any precip
that does fall will be light with no significant accumulations
expected.

&&

.PREV DISCUSSION... /issued 402 AM CST Sat Dec 17 2016/

SHORT TERM...
Plenty to consider again this morning with strong winds, frigid air
and even the threat of light wintry precipitation all in the
forecast through the day today. Additionally, elevated fire weather
and blowing dust will also occur in advance of the colder air across
at least the southwest South Plains.

Looking at the big picture, a vigorous storm system was making its
way through the Great Basin and toward the Four Corners early this
morning. The base of this trough will make quick headway through New
Mexico before swinging across the Panhandles this afternoon.
Impressive dynamics will result a brief period of strong
tropospheric lift spreading from west to east across the area from
late this morning through late this afternoon. This will occur as a
strong cold front moving through the Texas Panhandle moves into and
through the South Plains. As of 09Z the front was located roughly
from Boys Ranch, to Dozier, to Hobart. When the front went
through Dalhart in the past hour temperatures plunged from 55 to
25 degrees. Temperatures in the 20s and teens were common behind
the front while out ahead of it readings in the 50s and even lower
60s were common over much of the CWA. This cold air, with origins
from land that does not see sun this time of the year, will
continue to advance southward into and through the FA, in a
backdoor fashion, during the day today. The HRRR seemed to have a
pretty good handle on the front's location and speed and was used
heavily for the forecast through the day today. It does look the
front may slow a bit early this afternoon as it encounters the
strong and deep southwesterly flow. Latest best guess is that the
front will be located roughly from a Muleshoe to Lubbock to Lake
Alan Henry line midday before accelerating through the remainder
of the South Plains by around mid-afternoon.

Strong and deep southwesterly flow in advance of the front will
quickly be tapped as heating/mixing commences, and the southwest
South Plains will likely see winds increase to 35 to 45 mph with
gusts to 60 mph possible. Thus, a high wind warning has been issued
for Cochran, Yoakum, Hockley and Terry Counties from 16Z to 00Z.
Elsewhere, post-frontal northerly winds will increase into the 25 to
35 mph range, with higher gusts. Hence, a wind advisory will be
issued for the remainder of the CWA, also from 16Z to 00Z.

In addition to the magnitude of the wind, the northerly winds will
carry in the frigid air with temperatures quickly plunging below
freezing behind the front. In fact, temperatures by 00Z are expected
to range from around 10 degrees across the southwest Texas Panhandle
to the middle 20s across the southern zones. Temperatures will
continue to fall overnight with lows expected to range from near 0
around Friona and Tulia to 10-12 degrees over the southern South
Plains into the Rolling Plains. Here in Lubbock we may make it down
into the single digits for the first time since early in 2014. The
bitter cold combined with the winds will create wind chills in
the -5 to -15 degree range for much of the area. Given this, we
will also issue a wind chill advisory for all but our southern row
of counties where they may stay just a couple of degrees above the
-5 degree threshold for an advisory. Regardless, it will be COLD!

Lastly, the strong lift moving across the region later today will
bring the risk for a quick shot of precipitation, though limited
moisture will mean only light amounts are expected. The best chance
will initially develop over the southwest Texas Panhandle late
this morning, before spreading quickly eastward across the
southern Texas Panhandle and northern South/Rolling Plains through
the afternoon. It appears whatever precipitation that falls will
come out of the lowest half or so of the troposphere, as very dry
air will be present at and above 500 mb. A warm nose near 700 mb
(at or above 0C) could also support a little wintry mix before the
entire column cools below freezing and snow would be the dominate
mode. However, shortly after the mid-lower atmosphere saturates
and cools sufficiently to support snow the lift will be waning.
Thus, any amounts of rain/sleet/snow should be on the light side,
with NWP QPF generally under a tenth of an inch of liquid. A
dusting to a half inch of sleet/snow seem most probable with maybe
isolated totals near an inch. We don't expect to expect this light
frozen precip. in itself to be a big deal, but it could initially
melt on the roadways and then quickly refreeze as temperatures
plummet, so there definitely could be some slick spots out there.
We plan to handle the light wintry precipitation within the wind
chill advisory product.

LONG TERM...
The expansive cold surface ridge settling in across the central
and southern plains behind the front will begin to slide east on
Sunday. For our area, under mostly sunny skies, temperatures will
likely remain below freezing, with highs in the mid 20s to near
30, a very modest start to a warming trend for the upcoming week.
The upper-air pattern will bring a highly elongated broad trough
across most of the CONUS with mainly W-SW flow aloft over West
Texas. Forecast x-sections do show quite a bit of upper-level
cloud cover across the area Monday but temps will still warm up a
bit into the 30s and low 40s. Warming should be more pronounced
Tuesday as moisture aloft thins out, highs will push well into the
50s with some low 60s possible. A cold front will pass through on
Wednesday as a progressive shortwave translates across the
plains. Moisture and lift will be lacking with this wave but temps
may ease back into the middle 50s behind the front for Wed and
Thu. For the end of the week into Christmas weekend, the latest
GFS and ECMWF are not showing much consistency between each other
or run-to-run. However, both have backed away from any indication
of a closed system approaching from the desert southwest. The
ECMWF now has a weak trough passing to our north, resulting in a
dry and mild Christmas weekend. The latest GFS is suggesting a
deeper trough and strong cold front, which while not looking
very promising for snow, would at least bring in some winter-like
temperatures by Christmas Eve. Right now the main point is the
high uncertainty in the weather for next weekend.

FIRE WEATHER...
Very strong southwesterly winds (30 to 40 mph with gusts to 55 mph
at 20 feet) will combine with marginal humidities (20 to 30 percent)
to create a period of elevated fire weather ahead of a strong cold
front across the southwest South Plains from late this morning
through early this afternoon. Winds will abruptly shift to the north
and temperatures will drop extremely fast while RH values rise
behind the front this afternoon. This will bring an end to any
heighten fire danger.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 6 PM CST this evening for TXZ021>038-041>044.

Wind Chill Advisory until 9 AM CST Sunday for TXZ025>038.

High Wind Warning until 6 PM CST this evening for TXZ039-040.

Wind Chill Advisory until 9 AM CST Sunday for TXZ021>024.

&&

51/99/99

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LUBBOCK TX
1053 AM CST SAT DEC 17 2016

TXZ021>044-181700-
PARMER-CASTRO-SWISHER-BRISCOE-HALL-CHILDRESS-BAILEY-LAMB-HALE-
FLOYD-MOTLEY-COTTLE-COCHRAN-HOCKLEY-LUBBOCK-CROSBY-DICKENS-KING-
YOAKUM-TERRY-LYNN-GARZA-KENT-STONEWALL-
1053 AM CST SAT DEC 17 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTH PLAINS...ROLLING
PLAINS AND THE FAR SOUTHERN TEXAS PANHANDLE.

.DAY ONE...TODAY AND TONIGHT

A HIGH WIND WARNING IS IN EFFECT FOR THE EXTREME SOUTHWESTERN
SOUTH PLAINS. A WIND ADVISORY IS IN EFFECT FOR THE REMAINDER OF
THE OUTLOOK AREA AS WINDS WILL BE GUSTY BEHIND THE FRONT.

WIND CHILLS WILL BELOW ZERO FOR MUCH OF THE OUTLOOK AREA AS
TEMPERATURES CONTINUE TO DROP THROUGH THE DAY INTO THE EVENING.
A WIND CHILL ADVISORY WILL BE IN EFFECT FOR TODAY AND TONIGHT FOR
ALL OF THE OUTLOOK AREA EXCEPT FOR THE EXTREME SOUTHERN SOUTH
PLAINS AND ROLLING PLAINS.

ADDITIONALLY, LIGHT SLEET AND SNOW WILL SPREAD ACROSS ROUGHLY THE
NORTHERN HALF OF THE OUTLOOK AREA THIS AFTERNOON. ALTHOUGH AMOUNTS
ARE EXPECTED TO BE LIGHT...FROM A DUSTING TO HALF INCH. HOWEVER
THE SLEET AND SNOW MAY FREEZE TO THE ROADWAYS AND CREATE SLICK
SPOTS AS TEMPERATURES FALL WELL BELOW FREEZING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE WIND CHILL ADVISORY EXPIRES AT 9 AM SUNDAY MORNING.
THEREAFTER, THE PROBABILITY OF HAZARDOUS WEATHER IS LOW.