Area Forecast Discussion
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FXUS64 KLUB 141735
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
1135 AM CST Tue Feb 14 2017

.AVIATION...
IFR ceilings expected to continue at KPVW/KCDS through much of the
afternoon as storm-relative flow maintains light precipitation
and clouds in the wake of the exiting storm system. A band of
heavier showers with sleet will pass through KLBB after valid time with
gradually improving ceilings thereafter as drier air works in from
the southwest. Expect in-cloud icing to continue across northern
routes where deep, saturated profiles will be slower to dry.
Gusty north winds will taper off with time this afternoon.

&&

PREV DISCUSSION... /issued 410 AM CST Tue Feb 14 2017/

SHORT TERM...
The bulk of  precipitation with this winter storm system has pushed
east of the area as the center of the upper level low pushing
eastward just southeast of El Paso as of 2AM.  A dry slot is noted
immediately east of the center on WV imagery which is promoting the
dry conditions across our CWFA.  Some light echoes are evident
closer to the low, most notably near Carlsbad thus confirming the
enhanced lift under the mid level low.  A concern over the past few
nights was the temperatures behind an expected frontal boundary due
in from Colorado.  As suspected, the high temps yesterday across
that area failed to reach deterministic model forecasts and a 3-5
degree difference in initialized surface temps is noted on the NAM
amd GFS which more closely matches expectations over the past few
nights.  Given the interaction of the front, data suggest this will
initially keep temperatures a few degrees cooler longer this
morning.

With respect to the upper level features, virtually all solutions
appear to have poorly initialized on the closed circulation of the
low (clearly evident in WV in WTX) being a good 100NM too far north.
Granted, the overall structure is likely elongated N/S which is
hinted upon by the deformation region in NERN NM and SE CO. The
aforementioned dry slot appears to be already adversely affecting
that region.  A jet max is wrapping around the southern periphery of
the low and while another minor jet max is noted upstream, the
general tendency will be for the low to lift NEWD.  All this suggest
that the low`s cohesiveness and strength will be significantly
impacted as it tracks across our CWFA.  As such, any precipitation
will be very light.

Light precip is expected across the NW corner of our FA later this
morning and a few hours of very light accumulation will be possible
with the core drifting ESE into the NE South Plains.

In terms of precip phase, it looks like it is most likely to be
light snow in the NW with perhaps a dusting to an inch.  Ground
temps should keep any accumulations to a minimum.  As the system
pushes eastward, to around 100W, will probably see a -RA/-SN mix
across the NERN South Plains. While initially a few degrees too warm
for snow, wet bulbing should at least allow for some snow to reach
the ground though no significant accumulation is expected.

By mid afternoon, the system will be moving out with subsidence
helping to rapidly clear things out save perhaps a few high
clouds.

LONG TERM...
Northerly flow with upper level troughing will help keep Wednesday
on the cooler side (mid 50s). Surface winds will turn back to the
southwest by Thursday morning in response to surface troughing
extending from central Canada and will help to warm temps back into
the mid and upper 60s. The upper level trough that remains from the
early week storm system will begin to push eastward by Friday as it
gets kicked from a pow pushing inland from the Pacific. Friday has
the potential to be windy as a surface low develops across
southeastern CO on the back side of the upper trough. The GFS pulls
the surface low across the FA by the early evening while deepening
the low. The ECMWF is less bullish and slower with the surface low.
Wind speeds for Friday provided by the ECMWF, even for the slower
progressing surface low, appear to be too low (10-15 mph) given that
the surface low will be deepening through the day. The forecast will
reflect winds leaning more to MOS guidance.

Upper level ridging will dominate Saturday as the approaching trough
off the Pacific coast amplifies. This next trough appears to be our
next rain producer as it taps Gulf moisture at the surface and
Pacific moisture aloft. Thunderstorms would result ahead of a
dryline late Sunday into early Monday.

&&

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

$$

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