December 2017: End Of The Year Weather

[tireman4]

Front making its way through the Houston area...

[BlueJay]

Indeed. The temperature drop from 70F at 9'ish this morning to 60F now is big.

[tireman4]

From HGX...Twitter.....

[tireman4]

It is making its way folks...just hold on...

[tireman4]

000
FXUS64 KHGX 051625
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1025 AM CST Tue Dec 5 2017

.DISCUSSION...
A cold front continues to move through SE TX and temperatures will
drop about 15 degrees behind the front. Convection along the
boundary is weakening as an outflow boundary from earlier
convection is weakening the low level convergence along the front.
A weak upper level disturbance is producing a burst of convection
near the coast and this still warrants the likely PoPs for the
coastal counties through 18z. Will be tweaking sky grids, temp and
dew pts grids through the day to reflect current timing of the
front but the previous forecast is on the mark and do not plan on
any significant changes. 43

[tireman4]

000
FXUS64 KHGX 051756
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1156 AM CST Tue Dec 5 2017

.AVIATION...
The surface cold frontal position at noon was somewhere across
the coastal and second inland tier counties. Scattered precipitation
has mainly been rain but there have been some relatively stronger
eastern-moving cells moving across the coastal counties that have
gusted to 25 knots. Near term periods of IFR decks within bouts
of rain...precipitation to clear off coast by 3 PM. Upglide of
warmer more moist air atop this cooler near surface dome...along
with the vicinity middle level front...will provide the focus or
lift to re-generate more steady light stratiform rain this evening.
Gusty north winds to 20-25 mph in gust...near 35 mph along the
immediate coast. Wednesday`s raw conditions will primarily be of
low MVFR decks and -RA...with occasional lowering ceilings to IFR
near more moderate rain. 31

[tireman4]

Cold front has cleared the coast...now the temperatures will fall steadily throughout the afternoon into the evening.

[Montgomery]

Cold front has cleared the coast...now the temperatures will fall steadily throughout the afternoon into the evening.

How about that 32 in Huntsville or better yet the 20 in College Station!!

[MontgomeryCoWx]

Man, not only does Jimbo bring better Football to the Aggies, he brings winter weather!

[stormlover]

I am a big Seminoles fan, Yall better get read for a boring offense!! if he doesn't bring a qb like winston his scheme struggles!!!

[tireman4]

Cold front has cleared the coast...now the temperatures will fall steadily throughout the afternoon into the evening.

How about that 32 in Huntsville or better yet the 20 in College Station!!

Those are dewpoint temperatures...sorry about that, I should have switched the view

[tireman4]

Take this map with a grain of salt. Wxman 57 shared it on another channel...purty to look at....

[tireman4]

000
FXUS64 KHGX 052108
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
308 PM CST Tue Dec 5 2017

.DISCUSSION...
A cold front has pushed through SE TX and is entering the Gulf of
Mexico. A tight pressure gradient behind the front will bring a
strong NNE wind behind the front. It might be overkill but think
sustained winds along the immediate coast will reach 20-25 mph
with higher gusts and decided to go ahead and issue a Wind
Advisory. The strongest winds/greatest impact will likely remain
close to the coast. A series of weak upper level disturbances will
traverse the state over the next 36-42 hours and coupled with
weak isentropic upglide will yield periods of light rain. Rain is
expected to redevelop between 03-06z and expand in coverage by
09z. Would not be surprised if a few ice pellets mixed in with the
rain north of a Caldwell to Trinity line at the onset due to some
evaporative cooling and a low wet bulb temperature. Periods of
rain will continue on Wednesday as another disturbance crosses the
region. Temperatures will be cold with thick cloud cover, weak
cold air advection and precipitation. Doubt there will be of a
diurnal range in temperatures. Forecast soundings show a nearly
saturated profile on Wednesday so some moderate rainfall totals
are likely.

The GFS and ECMWF differ a bit with how long the precipitation
hangs around SE TX. The ECMWF is a bit more amplified in the upper
keeping more of a SW wind aloft Wed night into Thursday while the
GFS is more zonal. The GFS allows for a bit more low level drying
as well. The GFS has been trending toward the more aggressive
ECMWF so feel it`s best to increase rain chances through Wednesday
night and maintain a chance for precip into Thursday. A messy
forecast gets even messier as we move into Wednesday night.
Forecast soundings show a saturated profile above 8000 feet, The
thermal profile falls below 0 C so there could be some mixture of
rain and snow Wednesday night over the extreme north. First guess,
some mixed precip could occur north of a Caldwell to Trinity line.
1000-850 and 850-700 thickness values are marginally supportive of
a rain-snow mix but the forecast soundings for KCLL and
Madisonville look more favorable for snow. Surface temperatures
will remain relatively warm through Thursday, well above freezing
and there is a large chunk of dry air that the precip will have to
fall through, likely evaporating before reaching the ground. There
is a lot of uncertainty this far out so would prefer to keep the
precip type in the grids as rain for now and see if models come
into better agreement.

Drier air will gradually filter into the region from the north on
Thursday but light rain will probably linger near the coast and
toward the southern edge of the CWA. Clouds will limit heating on
Thursday and high temperatures will struggle to warm into the
middle 50`s. The upper level trough axis finally shifts east of
SE TX on Friday and any residual precipitation should end early
Friday as dry air continues to filter into the area. Sunshine is
expected to return by Friday afternoon.

The weekend and first half of next week look quiet with
seasonable temperatures and no precipitation expected. 43

&&

.MARINE...
The passage of an afternoon cold front will strengthen northerly
winds and allow seas to build through early Wednesday. The delay of
colder air over much warmer waters late Wednesday into early
Thursday...as it relates to tonight into early Wednesday`s
tight offshore pressure gradient...will likely just maintain
Advisory level winds. Tomorrow`s Gulf winds may occasionally gust to
gale thus had left the Gale Watch up...now in effect for the 20 to
60 nm waters from sunrise tomorrow morning through tomorrow
afternoon. Generally 20 to 25 knot bay winds with 20 to 30 knots
sustained winds over the Gulf from tonight through late Thursday.
Agitated seas will likely reach average 5 to 7 feet nearshore
heights...7 to 10 feet offshore. Winds and seas will begin to come
down Friday. Periods of long duration light rain on both Wednesday
and Thursday. Winds and seas will begin to fall on Friday. High
pressure settling in over the waters this weekend will produce a
significantly weakened light offshore flow pattern and average 2 to
3 foot sea heights. 31

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 41 46 39 53 33 / 80 100 60 30 10
Houston (IAH) 44 45 42 52 36 / 80 100 80 40 20
Galveston (GLS) 48 51 46 53 43 / 80 100 70 70 40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory from 6 PM this evening to 9 AM CST Wednesday for
the following zones: Brazoria...Chambers...Galveston...
Matagorda.

GM...Small Craft Advisory until 6 AM CST Thursday for the following
zones: Coastal waters from Freeport to the Matagorda Ship
Channel out 20 NM...Coastal waters from High Island to
Freeport out 20 NM...Galveston Bay...Matagorda Bay.

Gale Watch from Wednesday morning through late Wednesday night
for the following zones: Waters from Freeport to the
Matagorda Ship Channel from 20 to 60 NM...Waters from High
Island to Freeport from 20 to 60 NM.

Small Craft Advisory until 6 AM CST Wednesday for the following
zones: Waters from Freeport to the Matagorda Ship Channel
from 20 to 60 NM...Waters from High Island to Freeport from
20 to 60 NM.

&&

$$

Discussion...43

[CrashTestDummy]

Take this map with a grain of salt. Wxman 57 shared it on another channel...purty to look at....

Um, no.

[DoctorMu]

Take this map with a grain of salt. Wxman 57 shared it on another channel...purty to look at....

Um, no.

lol Texas snow still on the GFS and Canadian:

[DoctorMu]

Cold front has cleared the coast...now the temperatures will fall steadily throughout the afternoon into the evening.

How about that 32 in Huntsville or better yet the 20 in College Station!!

Those are dewpoint temperatures...sorry about that, I should have switched the view

Nice dew points...that means...






Nice and cold at 850 on the Euro:




Consistency across models.

[Katdaddy]

Its a cold wet December morning across SE TX with temps in the mid to upper 40s which will continue through the day. Stay warm and drive safe this morning.

[MontgomeryCoWx]

Winter has arrived! Love it!

[srainhoutx]

I noticed some changes overnight via the guidance suggesting the column is much more saturated than previously predicted into Thursday night/early Friday morning. I would not be surprised to hear a few reports of sleet pings coming in across our Region. Also, the temperature forecast is going to be very tricky with trends toward freezing temperatures along and N of I-10 early Saturday morning. The freeze longevity potential has increased somewhat with the potential of some locations dropping to near or below freezing for 4 to 6 hours. Gardeners be advised.

[srainhoutx]

Wednesday morning briefing from Jeff:

Winter Storm will move across TX today into Thursday

What the difference 24 hours makes…as strong cold air advection has resulted in temperatures falling into the lower to mid 40’s area wide compared to the lower 70’s at this time yesterday morning. Radar shows two bands of light to moderate rainfall over the region this morning with one favoring the coastal counties and the other generally NW of US 59. Strong jet stream aloft will continue to pump warm and moist air over the top of the cold surface dome allowing gradual lifting of the air mass and periods of rain. Biggest change overnight with respect to any winter type precipitation over the area has been the fact that the low level are more moist then forecasted and this will help to prevent evaporative cooling of the air column to support any mixed precipitation phases. A surge of drier air does begin to move into the region from the NNE early Thursday and this may offer a brief window Thursday morning where some sleet could mix with the rain, but think most areas will see a cold rain. Profiles south of HWY 105 are just too warm for anything other than liquid tonight into Thursday morning.

Rain will slowly end from N to S on Thursday into Thursday night, but the core of a cold upper level trough will move across SC TX Thursday night into Friday morning. Models continue to show the potential for the air column to cool across SC TX into the coastal bend region Thursday night/Friday morning suggesting a better potential for a mix of rain and sleet/snow. NAM is the most aggressive cooling the above freezing layer to nearly 500 ft above the ground which would likely allow snow/sleet to reach the ground, while much of the rest of the guidance has a much thicker (2000 ft) above freezing layer which would result in much of the sleet/snow changing back to rain or possibly a mix. Appears the Matagorda Bay region will lie on the northern edge of the precipitation shield with much drier air filtering in across much of SE TX by Thursday evening. Cannot rule out some sleet mixed with any lingering rainfall south of I-10 Thursday evening.

Other item of interest this morning is the potential for freezing temperatures Friday morning. Upper trough will be moving east of the area early Friday allowing clearing skies and with temperatures already in the mid to upper 30’s it will not take much to lower them toward freezing or below. Additionally, much drier air mass with dewpoints well into the 20’s will be arriving Thursday afternoon and evening which will help with the temperature fall. Think areas north of HWY 105 will fall below freezing for 3-4 hours Friday morning and may touch freezing as far south as I-10 away from the urban influences.