December 2016- End Of Year Forecast

[Heat Miser]

Chilly and wet; at least it will feel more like Christmas around these parts. Throw in a nice nighttime thunderstorm and all will be well.

[MontgomeryCoWx]

Chilly and wet; at least it will feel more like Christmas around these parts. Throw in a nice nighttime thunderstorm and all will be well.

That's the spirit! Much better than last christmas for sure!

[srainhoutx]

The afternoon updated Climate Prediction Center Day 6 to 10 Outlook that takes us into the Christmas Holiday period suggests below normal temperatures and above normal precipitation. The Day 8+ Analogs continue to advertise a Western Ridge/SE/Eastern Ridge pattern with toughing across the Great Basin into the Great Plains.

[Katdaddy]

Waiting in line for the TX temperature roller coaster ride this evening. The next few days will warm to near record highs Saturday across SE TX followed an AstroWorld Texas Cyclone drop into the 40s late Saturday and early Sunday morning.

[DoctorMu]

I'm up in Dallas and the TV mets are saying a 50-degree drop from sat pm to sun am...

50°F drop in CLL expected from Saturday afternoon to Sunday night, just a little over 24 hours. 44° drop in about 12 hrs.

[unome]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
602 AM CST Thu Dec 15 2016

.AVIATION.../12Z TAF/
Surface analysis shows high pressure over the plains allowing for NE winds across much of SE Texas this morning. Satellite imagery shows some low cloud cover across the area but observations indicate some clearing to the E and NE of KUTS/KCXO/KIAH. The expectation is for drier air to filter into the area from the east and gradually erode cloud cover. Ceilings are VFR at most terminals with KGLS the lone exception with MVFR. Model guidance and forecast soundings are in good agreement with some clearing this afternoon but there will be a return of lower CIGS. Warm front should push north tomorrow morning which means ceilings will begin to lower after midnight with showers possible in the morning. The 30 hr TAF for IAH does indicate possible IFR as the warm front moves through the area. Think there will be a mix of low ceilings, fog and light rain/drizzle for the late morning hours on Friday.

Overpeck


&&

.PREV DISCUSSION... /ISSUED 414 AM CST Thu Dec 15 2016/

DISCUSSION...
Important items of note for this forecast include:
- Possible fog/sea fog formation Friday night and Saturday
- Thunderstorm chances late Saturday and Saturday night
- Southern extent of freezing temperatures Sunday night/Monday morning

High pressure over the northern and central Plains will extend into SE Texas today. The zonal flow aloft will help to quickly move the high pressure ridge eastward and will result in an onshore flow returning across the forecast area by tonight. A strong cold front will move through SE Texas late on Saturday with a slow modification of the cold airmass occurring beginning on Monday. Another cold front may arrive as early as the middle of next week.

As the surface high pressure ridge pushes eastward, southwesterly winds will help set up a fairly large capping inversion. Both the NAMBufr and GFSBufr show the cap persisting through Saturday afternoon. The inversion breaks down Saturday evening as the front moves toward the area. Southwesterly winds at 850 mb were 45 to 50 knots on the GFS midday on Friday. Even with a cloud cover, the southwesterly flow should result in very warm surface temperatures on Friday and Saturday.

Although not mentioned in the forecast at this time, sea fog formation may begin by late Friday. The onset, extent, and duration of the event will depend upon the trajectory of the surface winds over the cooler continental shelf waters. If fog does form, it could persist into Saturday.

Following the front, freezing temperatures are looking likely over the northern half of the forecast area Sunday night and early Monday morning. Current model blends show the potential for freezing temperatures to reach as far south as Interstate 10 early Monday morning. Northerly winds could aid in lowering wind chills into the teens Sunday night and Monday morning as well. Monday is looking to be another chilly day. A slow warmup will then occur ahead of a second cold front that may move into the area during the latter half of next week.

40

MARINE...
Latest surface analysis at 09z shows high pressure building over the Plains allowing for moderate to strong northeast winds. Small craft should exercise caution this morning with stronger winds and moderate seas. Winds and seas should decrease later today.

Overall model guidance remains on track with regards to the wind forecast for the end of the week. Tonight into Friday return flow begins with winds turning southeast by Friday morning. Gulf moisture should increase during the day and there appears to be another favorable set up for sea fog development Friday night into Saturday. Moisture will linger into Saturday evening ahead of the cold front so there may still be a chance for sea fog. There will certainly be increased chances for showers given the warm advection pattern. Strong southerly winds also develop so look for the possibility of seas building to 6 to 8 feet Saturday. Small craft advisory will likely be needed during this time. A strong cold front should push off the coast early Sunday morning which will shift winds to the north. Models are now all about 3 hour faster bringing the front off the coast closer to 06-09Z Sunday. Wind speeds behind the front may reach 30 to 35 knots with gale force wind gusts or higher. This means very rough seas should develop in the range of 9 to 12 feet in offshore waters. Winds should decrease overnight into Monday but small craft advisories may still be needed Monday morning.

Tide levels should run near or about a half foot above normal today and Friday. With winds increasing Friday night into Saturday, tides could push 1 foot above normal and may need to be monitored for coastal flooding impacts. Right now this puts tides just at 3 feet MLLW which would be just below thresholds for impacts.

Overpeck

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 57 47 70 64 77 / 0 10 20 20 20
Houston (IAH) 58 46 74 69 79 / 0 10 20 20 20
Galveston (GLS) 57 55 72 69 76 / 0 10 20 20 20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX... NONE.
GM... SMALL CRAFT SHOULD EXERCISE CAUTION until 9 AM CST this morning 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... 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...40
Aviation/Marine...39

[srainhoutx]

Thursday morning briefing from Jeff:

Strong arctic cold front will blast across TX this weekend.

A great warm up will commence on Friday and continue into Saturday ahead of a strong arctic cold front which will move across the region Saturday night. Record high temperatures near 80 degrees will be possible on Saturday before the bottom falls out overnight. Warm air advection pattern will begin in earnest tonight into Friday with moisture returning to the region. May see a few showers, light rain, and drizzle late tonight into Friday and Saturday under the SE low level flow. High dewpoint air mass will spread across the cool nearshore waters and likely result in a bout of coastal sea fog from late Friday into much of Saturday.

Arctic boundary with a significant drop in temperatures will enter NW TX Saturday morning and blast off the coast overnight Saturday. Am tempted to go with the faster frontal timing as such dense cold air masses tend to move quicker than guidance suggests. Capping inversion will be in place nearly all day on Saturday and then begin to erode with the arrival of a weak short wave and the surface front Saturday evening. Could be enough ingredients to come together to produce a line of thunderstorms with the front, but SE TX will lie on the western edge of deeper convection over LA and experience with these sort of set ups tend to focus the more aggressive convection just east of our area.

Upstream air mass over the northern plains will be bitter cold with surface temperatures running sub zero and this combined with snow cover from a departing storm system will help to prevent as much modification of the air mass compared to the previous one last week. 6-12 hr temperature falls of 35-40 degrees will be common over SE TX from Saturday afternoon to Sunday morning. Temperatures will likely fall a solid 20-25 degrees within minutes of the frontal passage Saturday night or from the upper 60’s into the 40’s. Strong cold air advection on Sunday will continue to drive a very cold N TX air mass southward and temperatures may continue to slide into the 30’s during the day as upstream temperatures will hold in the 20’s over a large part of N TX. Strong winds and generally overcast skies behind the front will result in wind chills on Sunday into the 10’ and 20’s over much of the area.

Freeze potential for Sunday night into Monday morning is greater especially for areas along and N of I-10. Potential does exists for a more damaging advective type freeze where freezing surface temperatures are pushed southward under strong north winds. This type of freeze compared to a radiative freeze eliminates the effectiveness of covering sensitive vegetation and using the “greenhouse effect” of trapping near surface warmth. Wild card will be the amount of cloud cover during this period although given the intensity of the upstream air mass not sure just how much that aspect is going to matter. Raw guidance is showing mid 20’s for the College Station area and upper 20’s in Houston so something to keep an eye on over the next few days. Will need to keep an eye on wind chills Monday AM especially up north as surface temperatures in the mid 20’s combined with 10-15mph winds could drive wind chills into the 1’s.

[redneckweather]

I see latest models runs have trended quite a bit warmer for Christmas. Thoughts?

[davidiowx]

I see latest models runs have trended quite a bit warmer for Christmas. Thoughts?

I think it will trend back cooler as we get closer. Models will continue to flip all over the place. Just a few days ago they lose the arctic from that is going to push through Saturday evening here. We will just have to wait and see.

[MontgomeryCoWx]

Christmas is colder per latest run....

[redneckweather]

Christmas is colder per latest run....

Just saw that. lol

[srainhoutx]

The morning Updated CPC GFS Super Ensembles Day 11+ Analogs really have not changed regarding the expected Hemispheric Pattern expected around Christmas. Notices the Red shades across the Northern and NE Pacific as well as the SE and Eastern United States. A deep anomalous cold upper trough (indicated by the Blue shades) extends from Eurasia and Western Siberia across the North Pole into Alaska, Western Canada into the Great Basin and into the Great Plains. Also notice the Red (Upper Ridging) over Central Siberia where temperatures are currently running -50+ below zero.

[Heat Miser]

Watched one forecast last night that had us with highs in the mid 40's for Christmas eve and day, cloudy skies. That will be perfect weather for Christmas in my books.

[MontgomeryCoWx]

Watched one forecast last night that had us with highs in the mid 40's for Christmas eve and day, cloudy skies. That will be perfect weather for Christmas in my books.

Agreed. We have a traditional football game on Christmas Day between the families, and 80 degrees last year was disgusting. I like it (at least) below 60, but preferably below 50.

[StormOne]

Nothing will be necessarily reliable this far out regarding how Christmas will feel. It does seem like it won't be as bad as last year, but that is all that can really be said right now. The models are currently in the "what the heck, it went from 10 inches of snow, to a dusting, and back up to 5 inches" phase. This far out, pretty much everything the models say should be taken for a grain of salt.

[Portastorm]

Cool, raw day here in south central Texas. Forecasted highs were mid 50s but we barely hit 50 at 2 p.m. Thick cloud cover holding strong like yesterday. Has that "winter" feel to it.

[brooksgarner]

Watched one forecast last night that had us with highs in the mid 40's for Christmas eve and day, cloudy skies. That will be perfect weather for Christmas in my books.

Hey, Mr. Heat Miser: KHOU doesn't do 10 day forecasts because they're unreliable. Are you cheating on us??

[Katdaddy]

The SE TX weather roller coaster ride begins tomorrow morning as temps begin climbing to near record highs by Saturday in the upper 70s to low 80s followed by a significant drop in temps with the passage of a "Blue Norther" dropping temps by 30-35F from Saturday to Sunday into the 40s. The potential will also exist for some strong to severe storms mainly over E portions of SE TX and into LA.

Portions of NTX from Dallas-Ft Worth and areas N toward the Red River may see a light dusting of snow Saturday night into early Sunday morning.

Some extreme temp gradients for the TX Panhandle this weekend. 75F Friday and 2F Sunday morning at Pampa, TX. A 73F temp change.

Its not often we get to enjoy Summer and Winter in the same weekend. A beautiful Upper TX Coast to start the weather ride.

[unome]

107 degree difference

http://www.wpc.ncep.noaa.gov/discussion ... sc=nathilo

National High and Low Temperature (for the contiguous United States)
NWS Weather Prediction Center, College Park, MD
Issued 7 pm EST Thursday, December 15, 2016

High Temperature for Thursday, December 15, 2016
(as received by 7 pm EST December 15)
84 at Tucson, AZ

Low Temperature for Thursday, December 15, 2016
(as received by 7 pm EST December 15)
-23 at 13 miles northeast of Poplar, MT

[srainhoutx]

Warm front just off the Coast should move inland throughout the day as temperatures rebound into the upper 60's to low 70's with drizzle and fog developing this evening into tomorrow morning. Temperatures look to rise a bit further on Saturday as winds off the Gulf increase ahead of the Arctic front arriving across N Texas early Saturday morning. The sensible weather forecast has not changed with the Arctic front pushing through Central Texas mid day Saturday, passing College Station around 3:00 PM sweeping through Houston around 8:00PM and off the Coast around Midnight. There will be a 35 to 40 degree temperature drop in about 12 hours behind the front with very cold gusty winds. Temperatures may struggle to get out of the 30's for some locations N of I-10 on Sunday for daytime highs. There is still some uncertainty how far S the freeze line extends early Monday morning, but the best guess is somewhere along the HWY 59 corridor with temperatures in the mid to upper 30's to the Coast. Time to take precautions for those people that need attention in keeping warm with possible windchill values in the upper teens to low 20's and of course those outdoor pets and sensitive plants.