Area Forecast Discussion
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FXUS64 KLUB 151642 AAA
AFDLUB

Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
1042 AM CST Mon Jan 15 2018

.UPDATE...
The cold front is currently racing through the forecast area, and
about on top of Lubbock at this time. West Texas Mesonet obs show
winds speeds are the strongest across the far southwest Texas
Panhandle with Friona, Dimmitt and Hart in the 25 to 35 mph range
with gusts up to about 45 mph. Low stratus is filling in behind
the front about as expected as well. Temperatures won`t rise much
if at all for the remainder of the day except for the far southern
Rolling Plains. We`ve made small adjustments to the sky cover,
wind and high temperature grids. It still appears that the lack of
deep moisture or lift will keep any precip limited to a few
flurries and/or spritzes of drizzle/freezing drizzle. No
significant impacts are expected at this time.

&&

.PREV DISCUSSION... /issued 526 AM CST Mon Jan 15 2018/

AVIATION...
VFR conditions will start off the TAF but a strong cold front will
push across the terminals through the morning dropping ceilings
into low MVFR/high IFR range. Uncertainty still exists on how low
ceilings will become as current observations behind the front are
all IFR/LIFR. Wind speeds will gradually increase through the
morning gradually reaching the 20-30 knot range. Ceilings will
also slowly increase in height through the day likely becoming a
high MVFR to VFR ceiling around sunset local time. Wind speeds
will then decrease after sunset with some uncertainty on whether
MVFR ceilings will continue or if we will increase out of the MVFR
range into VFR range. Drier air filtering in tonight into Tuesday
morning will then erode clouds resulting in a very cold start to
Tuesday morning.

Jordan

PREV DISCUSSION... /issued 315 AM CST Mon Jan 15 2018/

DISCUSSION...
Models thus far have a good handle on a cold front currently
touring far southwest KS and adjacent CO. Surface obs reveal the
most robust cold air advection is lagging 150+ miles behind this
initial front and pressure jump, so in general we are not accelerating
FROPA ahead of model guidance much at all. Upshot of this is that
max temps were raised a few degrees in our southern row of
counties with few changes elsewhere. Moist northerly winds behind
the front should garner a thin shield of stratus spreading south
through the day and remaining largely intact overnight. However,
the arrival of markedly drier air overnight with the second surge
of cold advection will likely shove the stratus layer higher. This
should keep the door shut to any light wintry precip particularly
as the base of an upper trough in NW flow arrives Tuesday
morning. Models depict this low level drying well (something they
often lag with behind strong fronts) and depict cloud bases rising
to 6000 feet or higher through the night. Although model soundings
depict the top of clouds reaching -14C and colder toward daybreak
on Tuesday, a few flurries would be the most this setup appears
to hold for us, but even this is too conditional for any mention
in the forecast at this time. Deeper subsidence and drying behind
the trough axis on Tuesday will erode clouds from N-S, and this
theme is portrayed well by the latest MOS with highs a couple
degrees warmer than earlier iterations indicated.

Exodus of the chilly surface high on Wednesday will precede milder
thicknesses, although this warming looks to be stunted a bit by
neutral heights aloft courtesy of another weak trough in NW flow.
Winds aloft are still shown to turn more zonal by late week ahead
of a deepening trough upstream of the region. Raw models and
ensembles show good clustering of this trough reaching our CWA
Saturday night as the main vort max passes to our north. Very
similar to the wind and dust from last Wednesday, we would
escape the strongest wind potential on Saturday provided this
vigorous trough arrives overnight. Superblend`s dewpoints and
winds are not yet representative of this pattern, so we have
trended much breezier and drier on Saturday (mainly on the
Caprock) which would definitely enhance wildfire growth potential.
Also similar to last Wednesday, dynamic cooling aloft from height
falls could spur some light rain showers, although this signal is
too weak for any confidence in introducing measurable precip
chances at this time.

&&

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

$$

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