High Wind in Texas, November 30, 2018

Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1219 PM CST Fri Nov 30 2018

.UPDATE...
Clearing skies ahead of the incoming storm system across New
Mexico has started to ramp wind speeds up across the western South
Plains. Stronger wind speeds will continue to spread east across
the Caprock through the afternoon with sustained speeds 30 to 39
mph and gusts approaching 50 to 55 mph. Already seeing West Texas
Mesonet sites with sustained speeds around 35 mph along the TX/NM
state line. GOES-East Dust RGB is already showing a bit of blowing
dust near the state line with heavier amounts back in NM. Will
continue to see stronger wind speeds spread east as mixing
increases in the clear skies east of the departing clouds. Based
on the obs and how things are unfolding, have issued a Wind
Advisory until 8 pm for the Caprock. May take a bit of time for
wind speeds to decrease as strong jet remains over the forecast
area into tonight so the ending time may need to be extended as we
head through the afternoon. All products have been updated and
sent out.

Jordan

&&

.PREV DISCUSSION... /issued 1125 AM CST Fri Nov 30 2018/

AVIATION...
VFR conditions in place at all three TAF sites. Skies are clearing
from the west for all three sites and this will result in wind
speeds increasing through the afternoon. Expect southwest to west
wind 20 to 30 kts with higher gusts that could result in periods
of blowing dust. Do not expect visibilities to fall to MVFR but
there could be brief periods of MFVR visibilities at times. Wind
speeds will come down a bit after sunset to around 15 knots but
expect them to remain gusty at times, and then ramp back up to 20
to 30 knots Saturday afternoon again.

Jordan

PREV DISCUSSION... /issued 326 AM CST Fri Nov 30 2018/

DISCUSSION...
A dynamic pattern is setting up for the southern tier of the
continental U.S. as the southern branch of a split flow pattern
becomes dominant and active. A sharp upper level trough moving
across Nevada, southern California, and western Arizona this
morning is spreading precipitation across Utah and Arizona early
this morning. This trough will continue to move steadily eastward
today, deepening and closing off over the central High Plains
after it crosses the Rockies. This will leave the forecast area
south of both the surface low and mid/upper level closed system
favoring wind this far south. Models continue to suggest sub-
advisory winds this afternoon in part due to the main upper
feature staying back over New Mexico and Colorado until late in
the day and abundant thick mid and high cloud cover downstream of
the trough. In addition, models now take the initial mid level
wind max further south across the Permian Basin this afternoon.
Still, once initial thick cirrus begins to clear there should be a
surge in wind speeds solidly into the 20 to 30 mph range. There
are still some indications that modest lift combined with mid
level moisture and instability this afternoon could result in some
showers, the bulk of any precipitation likely not reaching the
ground. Moving into tonight, as the main mid level circulation
moves across the northern Texas Panhandle and southwestern Kansas
the strongest mid level speed max will rotate eastward across the
South Plains. Nighttime timing favor works in our favor, and
although wind speeds will stay in at least a 15 to 25 mph range,
we will miss out on maximizing the potential that this system
would have had had the speed max moved across during the
afternoon. The closed low will move quickly northeastward toward
the Great Lakes on Sunday with another upper low forming over the
Great Basin. This low will dampen as it moves across the Rockies,
but it will be associated with an exiting upper level jet streak.
The right rear quadrant of this jet streak combined with the low-
amplitude trough should support some precipitation from
northeastern New Mexico across the Panhandle and southward into
the northern half or so of the forecast area from late Sunday
through Sunday night. Some question still whether this precip
reaches the ground as rain or snow. Much will depend on the
strength of cold advection behind a cold front that will move
through the forecast area Sunday as well as how quickly low to mid
level cloud cover moves in, a later arrival would favor quicker
cooling during the evening and would support snow. Either way any
snowfall accumulations look minor at this time from this quick-
hitting system.

Beyond Sunday, the upper pattern returns to one from a couple
weeks ago with a broad trough over much of the CONUS supporting a
return to colder, if not much colder, than normal temperatures.
This might only be disrupted by short wave riding Thursday which
would support a brief warming trend before the arrival of the next
upper low or trough (and possibly the first decent chance at more
widespread precipitation in a number of weeks).

FIRE WEATHER...
Wind speeds this morning should remain pretty light, but
cyclogenesis in southeastern Colorado will tighten the pressure
gradient with increasing wind speeds this afternoon. How high
those winds get will depend greatly on how abundant mid and high
cloud cover is, but 20-foot winds in excess of 20 mph seems
certain on the Caprock. Biggest question is relative humidity with
current forecast keeping minimum values between 25 and 30 percent.
That is a little too high to support headlines of either an RFD or
RFW. Will hold off on the issuance of either product at this time.
Day shift may have to reevaluate later today. Saturday may hold a
little more promise as winds should remain gusty and relative
humidity holds a better chance of dropping toward 20 percent.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 8 PM CST this evening for TXZ021>023-027>029-
033>035-039>041.

&&

01/14

Hazardous Weather Outlook...UPDATED
National Weather Service Lubbock TX
1210 PM CST Fri Nov 30 2018

TXZ021>044-010615-
Parmer-Castro-Swisher-Briscoe-Hall-Childress-Bailey-Lamb-Hale-
Floyd-Motley-Cottle-Cochran-Hockley-Lubbock-Crosby-Dickens-King-
Yoakum-Terry-Lynn-Garza-Kent-Stonewall-
1210 PM CST Fri Nov 30 2018

This Hazardous Weather Outlook is for the South Plains, Rolling
Plains and the far Southern Texas Panhandle.

.DAY ONE...This Afternoon and Tonight

An approaching storm system will result in increasing wind speeds
through the afternoon across the Caprock. A wind advisory is in
effect until 8 pm for areas west of a Happy, Plainview, Lubbock,
to Tahoka line.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Elevated fire weather may develop Saturday afternoon on the
Caprock. Very light snow accumulation is possible Sunday night
across the extreme southern Panhandle and the northern South
Plains.