I'm a little more interested in the shorter range forecast regarding our sensible weather. Looks like we may have a shot at some rain Saturday night into Sunday with some over running rain continuing into early next week. That noisy sub tropical jet that has brought all the mid/high level cloudiness this week will continue streaming across Texas. A cold front will pass today with a Coastal low/trough developing in the NW Gulf on Saturday. A warm front may attempt to push back inland and some locations may see an elevated thunderstorm or two over night Saturday into early Sunday. The front pushes back offshore and another front arrives 20th and yet another on the 22nd.
Just think back a week ago this morning when we all were anticipating a snow event. Christmas Eve is still 10 days out and hanging on every swing of the model runs will drive you crazy... By next week we should see if this modeled blistering cold is a reality. Watch those temperatures in the Canadian Prairies. If they fall to -20 to -30, then we'll have an idea if the models have been correct.
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A weak cold front will cross the region this evening with rain chances increasing Saturday and Saturday night.
Low confidence forecast next week and beyond
A weak cold front will move across the region today and tonight with high clouds streaming across the area. Rain and thunderstorms will develop offshore on Friday and some of this activity may graze the coastal locations, but the bulk of the activity will remain offshore. Appears the surface front will remain over the area going into Saturday as a strong upper level storm system approaches from northern Mexico. Lift will spread across the region on Saturday along with rapid moisture advection. Expect rain chances to increase from SW to NE across the area on Saturday afternoon into the overnight hours. A few strong or even severe thunderstorms may form off the coast south of a warm front Saturday night with most of the area seeing widespread showers and isolated thunderstorms inland. Rainfall totals up to an inch will be possible especially near the coast with lesser amounts inland. Storm system will be fast moving and exit the area early Sunday with rain ending. No real air mass change behind this departing storm on Sunday and temperatures will begin to warm next week as southerly flow returns to the region.
May see some rain chances again toward the middle of next week as another front moves toward the area, but moisture return and quality may be in question.
Warm temperatures will remain in the forecast for much of next week with highs in the 70’s most days.
Extended:
As is common with model guidance the GFS has backed away with the intensity of the cold air mass around Christmas and beyond more in favor of the ECMWF solution. GFS still has a strong cold front arrives around the 24th across the area, but is not as cold as previous runs. Models tend to underestimate the intensities of these cold arctic air masses that can surge down the plains and extended range guidance usually struggle greatly with such events. There is really no confidence at this time as to what may transpire around Christmas or the week after with respect to the incoming cold air mass and how cold it may be and what if any precipitation may fall in that air mass. Use caution when viewing the extended range guidance and making an assumptions. This portion of the forecast will continue to be of interest over the next several days.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
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Just stay tuned as Srain would say...anything and everything can and will change. Still too far out.
000
FXUS64 KHGX 140936
AFDHGX
Area Forecast Discussion
National Weather Service Houston/Galveston TX
336 AM CST Thu Dec 14 2017
DISCUSSION...
One more day of quiet weather today across Southeast Texas before the
pattern becomes increasingly active as we head on into the weekend.
Lots of high clouds continue streaming across the area from the southwest,
and it is possible that these clouds could keep today`s temperatures
below expected highs. A cold front will move through during the day
today, and we will continue to carry increasing rain chances behind
the front for tonight with the lower values near the coast and the
higher values offshore. Some drier air moving into the area from the
north will help to lower rain chances on Friday and Friday night.
A northern Mexico storm system ejecting northeastward across the
state over the weekend will help to bring rain and maybe some isolated
thunderstorms to our area with the best chance currently looking like
Saturday night through early Sunday morning. Best dynamics look like
they will remain offshore, but any westward shift of this system could
edge the risk of any strong/severe storms inland. After most of the
area dries out during the day on Sunday with the exit of the system,
some rain could redevelop into Monday and Tuesday as weak and hard
to time mid/upper level disturbances move across the area under a
persistent southwest flow aloft. Currently anticipating drier/warmer
weather as we head on into the middle to end of next week.
It is still too early to correctly predict what kind of weather the
area will see over the Christmas holiday weekend. 42
&&
.MARINE...
Benign wx conditions expected today. A cold front will push off the
coast this evening with some post frontal rain developing in its
wake overnight. Winds will increase to around 25kt after midnight
and into Friday so will need SCA`s. Winds veer to the east and
expect a coastal trof/low to set up off the lower & mid Tx coast on
Sat...eventually tracking northeast up the coast and bringing some
unsettled wx across the area Sat night (winds, elevated seas,
storms and sea fog). Improving conditions on Sunday as this
disturbance pushes east of the area. However, wouldn`t be surprised
to eventually see a return of the fog sometime Sun-Mon ahead of the
next front penciled in for Tue morning. 47
&&
.AVIATION...
VFR conditions with continued mid/high level streaming overhead.
Weak frontal boundary should push north-to-south thru se TX between
18-02z. Possibly some post frontal rain developing closer to the
coast after 6z, but majority of precip should be offshore. 47
MontgomeryCoWx wrote:12z makes it 19 in a row showing an arctic front late next week.
Comes in much faster too. Arrives Friday morning with a storm arriving at the same time.
However, the 12Z GFS doesn't drop temps below freezing in Houston with the front. Upper 30s to low 50s for temps next weekend through Christmas, along with heavy rain. It's like pulling the arm of a slot machine with each GFS run. What will we get next pull? I wouldn't begin to trust it until maybe NEXT Thursday.
MontgomeryCoWx wrote:12z makes it 19 in a row showing an arctic front late next week.
Comes in much faster too. Arrives Friday morning with a storm arriving at the same time.
However, the 12Z GFS doesn't drop temps below freezing in Houston with the front. Upper 30s to low 50s for temps next weekend through Christmas, along with heavy rain. It's like pulling the arm of a slot machine with each GFS run. What will we get next pull? I wouldn't begin to trust it until maybe NEXT Thursday.
Arctic fronts don’t retreat either like the GFS shows. By the way, while I don’t trust the temp maps, the upper air still holds true for delivery of cold air. My location (Western Montgomery County) does get to freezing and goes well below the day after Christmas.
I think Wxman57 put it the best by saying the GFS is like pulling the handle on a slot machine. Last evening, the GFS has Louisiana getting in on the winter weather and in less than 24 hours, we now look to stay warm again. It's impossible to tell with these major swings in the runs.
when the cold source happens real time up north then there is a possiblity the model forecast will verify. Like wxman said - next week this time - we should know more.
The afternoon Updated Climate Prediction Center Day 8 to 14 Outlook suggests colder and wetter weather may be possible over the long Christmas Holiday period. Also I see the 12Z GEFS 700mb charts suggest a rather deep SW to NE trough across our part of the World. Still a highly uncertain forecast, so continue to expect changes in the days ahead.
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Some larger changes are possible in the day 8-10 time period when
models have persistently shown deep troughing engulfing much of
the Central US. This pattern would be favorable for delivering
multiple shots of arctic air to the Central US and Southern
Plains, the first of which could arrive in Texas at the end of
next week. By now, we`ve all seen far too many model graphics
irresponsibly floating on social media depicting winter weather
potential due to this pattern shift. While it`s important we
acknowledge some winter weather is a possibility in the Dec 22-27
time frame, it`s much too early to suggest this is a guarantee. It
is something we`ll certainly be monitoring in the next several
days and will introduce if/when appropriate.
Bring on winter! Though I think we could do without the ice. Thankfully we are not travelling this year. MIL is coming here the Friday before Christmas. I hope the ice, if we do get some, holds off until she gets here. Most of our outside pipes are already wrapped, will wrap the remainder this weekend just to be on the safe side. I think it was the winter of 1988, or was it 1987, when we had all the brown outs and major freezes? We had a pipe burst in our attic, dh tried to crimp it, than we sprung another leak. Could not find a plumber, so we were without water for Christmas Eve and Christmas Day. I call it our Little House on the Prairie Christmas. Our neighbor had water so we were bringing buckets to her house and filling them. I even heated water on the stove to take a bath!
I will be watching the forecast here as I always do now. Thank you Pro Mets for all you do to keep everyone informed!
big weather story is the forecast leading up to Christmas.
For several days we've been seeing indications of a long-wave
pattern shift across North America with virtually all of the
guidance showing a flip from an East Coast trough to either a
West Coast or Plains trough. The latter solutions certainly spell
colder temperatures for our region. Model guidance is clustered
around a strong frontal passage in about 1 week (Thursday night).
Upper level ridging across the Canadian Pacific coastline will
induce strong anti-cyclogenesis and tap into a pool of arctic air
and send it southward into the northern Plains. Just how much of
this Arctic air makes it into our region is uncertain and highly
dependent upon the exact configuration of upper level pattern and
how it evolves.
Over the past several days we've seen wild run to run variations
of the upper level pattern so it is much too early to say with
confidence just how cold it will get or whether there is a threat
of wintry precipitation. A stronger and slower evolving trough
like what the ECMWF has been showing for several runs means a more
shallow and modified cold airmass will succeed the front for the
22nd and 23rd. While a solution like the GFS which quickly digs
the upper trough into the Desert SW would bring in a very shallow
but arctic airmass right behind the front. Both the GFS and ECMWF
forecasts raise our concern for wintry precipitation. The GFS
continues to indicate a risk of freezing rain on the 23rd and the
ECMWF is now indicating mixed precip on the 24th and 25th.
Obviously those forecasts are 8-10 days out and we would be
shocked to see a perfect forecast from either model. However the
verifying forecast could be in that ballpark, or it could look
like the Canadian and most of the ensembles means which are much
faster and farther east with the upper level trough. This would
bring a deep and very cold airmass into the region with clear
skies and no chance of precip.
In summary, the key points:
1) Confidence in colder weather arriving in about 1 week is high.
2) There is tremendous uncertainty regarding the post-frontal
precipitation potential.
3) As always, more confidence will come with subsequent
forecast data. The sooner all computer models settle on a
solution the sooner we can provide more difinitive forecast
guidance. At this time, model spread remains MUCH too high to
"sound the alarm" for a winter event.
It took some hunting, but I found the old article about the RGV freezes I was looking for. The original article from Richard Travis (a well-known Texas gardener) is no longer hosted, but fortunately someone on PalmTalk had copied the text:
This freeze may forever be known as the freeze that killed the palm trees in the Valley. Anyone who lived in the Valley before 1983 remembers well the thousands of tall slender Washingtonia robusta lining the local roads for mile after mile. The dead stumps were a sad sight on the Valley skyline for several years afterwards -- some still remain to this day. Citrus also received a good beating, the worst since 1951. The Valley got such a cleaning from 1983 it would almost make the worst freeze of the century seem anticlimactic.
About the same although the EPO goes really extreme on us.
Output shows HOUSTON from 30 to 40 degrees starting on the 22nd thru hour 384. HOUSTON has a sleet/ice storm towards the end of the run. Dallas gets hammered by freezing rain for a couple days.
As has been discussed, the cut off low scenario moderates our temps some versus the scenario where the low moving east with the trough would bring much colder air to us.
Personally, my preference is the cutoff low because it brings a lot of precip to Texas, and the models have a warm bias with these fronts.
The latter scenario would bring very cold and dry conditions.
While I understand the importance of models to indicate possible and or probable overall changes in the weather, by no means this far out should you give them more credit than they're due. In other words, live by the models, die by the models. They are but just one piece of the puzzle pieces. As we've all seen through the years they can be incredibly wrong in their long range forecast. I will say this with 100% certainty, when wxman gets frazzled or excited about snow, I tend to believe him. He's a veteran meteorologist who's seen and experienced too much weather not to listen to.
Model hugging, I absolutely loathe. Any professional worth their weight in salt probably can get a hint of what could come in maybe two to three days, but over a week or two, C'mon. And sometimes the weather surprises us up until the event unfolds or commences. It's not an exact science, but a science with educated guesses assisted by models.
By next week we should see if this modeled blistering cold is a reality. Watch those temperatures in the Canadian Prairies. If they fall to -20 to -30, then we'll have an idea if the models have been correct.
