Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Houston/Galveston Texas
619 PM CST Monday Dec 22 2014
see 00z aviation discussion.
VFR conds will prevail at most taf sites through 06z with sky
conds transitioning to MVFR ahead of a cold front. Kgls had a
brief bout with low ceilings earlier in the evening associated with
some sea fog just off the coast. Forecast soundings show a reasonably
deep saturate layer that feel some light rain will be possible
along and behind tuesdays cold front. Ceilings will also lower to
IFR/LIFR in the wake of the front. Winds will become strong in the
wake of the front as well so will carry a gust group again. VFR
conds expected to gradually return after 00z Wednesday. 43
Previous discussion... /issued 535 PM CST Monday Dec 22 2014/
quick update to grids to add mention of patchy fog for coastal
areas this evening where afternoon visible satellite and
Galveston webcams show a low stratus deck/fog bank sitting just
offshore. Guidance depicts winds backing from the southwest to the
southeast during the overnight hours and expanded fog mention to
inland areas as this occurs...with areas of fog likely developing
along the coast courtesy continued low level moisture advection.
Previous discussion... /issued 355 PM CST Monday Dec 22 2014/
quite a lot more sun across southeast Texas today than there has been these
last few days...with temperatures responding accordingly. Not too
many changes with the forecast as models remain in fairly good agree-
ment with the timing of the advertised strong cold front. However
we are seeing hints that a pre-frontal trough during the overnight/
very early Tuesday morning hours will help to shift winds/limit moist-
ure for when the official cold front arrives. Not too comfortable
with lowering probability of precipitation too much at this time...given the strong lift with the
front itself so will keep with the mostly chance probability of precipitation already in the
grids for frontal passage.
Nice cool down prognosticated in the wake of this front by Tuesday night as
the airmass builds down off the northern plains. Cool/dry weather Wednesday with
light/moderate cold air advection will give way to warming temperatures/return of onshore by
Thursday (christmas day) as high pressure moves off to the east. Excessive-
tended models keeping with the steady parade of fast moving upper
level longwave troughs across the U.S. For the rest of the week (on
into next week). This should translate to a series of cold fronts
for southeast Texas during this timeframe (one Friday then another next tues).
All in all a fairly typical El Nino pattern for US. 41
Preliminary point temps/pops...
College Station (cll) 52 57 37 53 35 / 20 40 10 10 0
Houston (iah) 57 61 40 54 36 / 20 40 20 10 0
Galveston (gls) 62 65 45 54 44 / 10 30 10 10 0
GM...Small Craft Advisory from 3 PM Tuesday to 6 am CST Wednesday for
the following zones: Matagorda Bay...waters from Freeport
to the Matagorda Ship Channel 20 nm to 60 nm...waters from
Freeport to the Matagorda Ship Channel out 20 nm.
Small Craft Advisory from 6 PM Tuesday to 6 am CST Wednesday for
the following zones: Galveston Bay...waters from High
Island to Freeport 20 to 60 nm...waters from High Island to
Freeport out 20 nm.