Area Forecast Discussion
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FXUS64 KLUB 100541

Area Forecast Discussion
National Weather Service Lubbock TX
1141 PM CST Fri Dec 9 2016

Shallow near saturated layer still raises the concern for low
cloud and/or fog development through the remainder of the
overnight. However, to this point no low clouds or visibility
restrictions have been observed or detected on satellite.
Short-range NWP continues to back off on overall cloud/fog
development/coverage, though still can`t rule out a period of MVFR
or even IFR conditions, particularly at KLBB or KPVW. Given the
uncertainty and lack of confidence, decided to split the middle
and have included tempo groups with MVFR conditions from 10-14Z
for KLBB and KPVW. Sub-VFR conditions look even less likely at
KCDS and have been excluded from the TAF. Light
southerly/southwesterly winds overnight will become breezy Saturday


.PREV DISCUSSION... /issued 322 PM CST Fri Dec 9 2016/

Stratocu deck continues to lift and thin this afternoon on the
back side of a cold surface ridge crossing the Mississippi
River valley. Lee side trough development from southeast Colorado
into northeast New Mexico has resulted in gusty southwest winds. This
feature will remain present through Saturday as fast zonal flow aloft
develops. Temperatures at 850 mb increase some 10C over today which
should equate to around 20F warming in highs temperatures on
Saturday. Only real question in the short term is if we will see
a redevelopment of low clouds overnight as moisture advection and
isentropic ascent occur on southwest winds above the surface.
Traditionally this is not a favorable trajectory for low clouds and
especially surface-based stratus however with clearing skies this
evening, sufficient diurnal cooling should take place for low cloud
development toward daybreak. Anticipate the cloud deck to be much
more shallow than today so no real impact on daytime temps expected.
As mentioned, winds will be breezy again Saturday in the 15-20 mph

If there exists a theme for the synoptic pattern in the extended, it
can be grouped as largely zonal.  There will be a couple of
disturbances that pass to our north as they rotate around a low in
north-central Canada.  One of the more significant bursts of energy
will occur on Monday followed by another on Wednesday.  Thereafter,
guidance becomes much less coherent to our west thus sharply
reducing confidence in the large scale evolution.

In terms of sensible weather:  Breezy conditions will persist
Saturday night as pressure gradient tightens with Sunday becoming a
bit on the windy side with respectable westerlies during the day.
Then, toward the latter afternoon, a cold front will make its way
into the area with classic fashion.  Return flow will quickly become
re-established on Monday thanks to the zonal flow. Then,
Wednesday morning will see the strongest of the frontal surges for
the upcoming week with breezy to possibly windy post-frontal
conditions. It will also usher in another round of cold air for us
which are, in many ways, similar to what we saw earlier this week.
In terms of precipitation, there doesn`t look to be any though we
should always keep an eye for isentropic upglide in the post-
frontal environment.

In terms of deviating from the blends, have upped wind speeds for
Sunday and more significantly on Wednesday behind the front.  Blends
tend to undercut speeds with these features...which are generally
better handled via MOS. Some concern exists with the potential for
post-frontal cloudiness on Wednesday which would keep things on
the cold side for Thursday. Models did not handle post-frontal
cloudiness well on the last system.




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