December 2014: New Year's Eve Wintry Mix Possible

[BlueJay]

Those pictures look cold, srain-Brrrrr!

Our temperature has dropped from 71F to 49F currently. The rain gauge claims we got 1.19 inches today. That's good. We needed the rain, but I 'm not sure we "needed" the temperature drop. Oh well. It is winter.

[Kludge]

I am by-no-means a meteorologist, or even a well-trained weather intern. I've just been fascinated by weather and physics throughout my life. The Internet has opened a whole new set of doors to my fascination.

I say this as a preamble to my discussion about the upcoming week's weather.

Growing up in Waco, it always seemed to be almost Christmas before we got our first freeze; nowadays it seems strange if they haven't had a freeze by Thanksgiving.

A "white Christmas" was just a fantasy. But New Year's Eve/Day winter weather was not rare. It seemed that if we had winter precip on those days, it was a sign that we were in for a more icy-than-usual winter.

I came to Houston to attend college in '77. So I've been studying and experiencing central and southeast Texas weather for 55 years now... and my uneducated "gut feel" for this week is: ice storm for the areas between I-10 and I-20, and mainly east of I-35.

We're into a wet southwesterly overrunning pattern, and with the shallow arctic air on the way... well, let's just say all the players will be on the field. I would so much prefer snow... but I'm afraid the subfreezing air will be way too shallow.

I will use the balance of my weekend to (root for Case and the Texans!!!...and) make sure the backup power is ready, since I'm afraid the rural power lines won't be able to bear the weight of a half-inch of freezing rain.

I really hope I'm wrong.

[As stated above, I am NOT a trained meteorologist, so tune to the NWS for expert forecasts]

[Paul Robison]

Written in stone?



hope not.

[srainhoutx]

I am by-no-means a meteorologist, or even a well-trained weather intern. I've just been fascinated by weather and physics throughout my life. The Internet has opened a whole new set of doors to my fascination.

I say this as a preamble to my discussion about the upcoming week's weather.

Growing up in Waco, it always seemed to be almost Christmas before we got our first freeze; nowadays it seems strange if they haven't had a freeze by Thanksgiving.

A "white Christmas" was just a fantasy. But New Year's Eve/Day winter weather was not rare. It seemed that if we had winter precip on those days, it was a sign that we were in for a more icy-than-usual winter.

I came to Houston to attend college in '77. So I've been studying and experiencing central and southeast Texas weather for 55 years now... and my uneducated "gut feel" for this week is: ice storm for the areas between I-10 and I-20, and mainly east of I-35.

We're into a wet southwesterly overrunning pattern, and with the shallow arctic air on the way... well, let's just say all the players will be on the field. I would so much prefer snow... but I'm afraid the subfreezing air will be way too shallow.

I will use the balance of my weekend to (root for Case and the Texans!!!...and) make sure the backup power is ready, since I'm afraid the rural power lines won't be able to bear the weight of a half-inch of freezing rain.

I really hope I'm wrong.

[As stated above, I am NOT a trained meteorologist, so tune to the NWS for expert forecasts]

Thanks Kludge. One of the neat things about our Board is the Decades of experience across our Region. Your analysis is appreciated. We have Jeff that interned at KHOU in his early days and wxman57 as well as ALL of our "Team". It's what makes the venue a great learning tool.

[Snowman]

So do the models have a handle on the situation this week or might it still be colder than expected? especially for the austin area

[Portastorm]

So do the models have a handle on the situation this week or might it still be colder than expected? especially for the austin area

IMO, no. Last night's 0z Canadian model came in colder than the previous GFS runs or the Euro. Another model one cycle later (Parallel GFS) also looked colder. But I don't think they're still grasping the magnitude of the cold coming with a 1050+ me high coming down into the Plains.

It sleeted this morning in scattered areas of the AUS metro area. That wasn't in yesterday's forecast. If the models are struggling with the current cold airmass (not as strong as what's coming), how can we buy into them 72 hours out?

[redneckweather]

No, models are not grasping the cold that is coming down next week. This latest front which wasn't supposed to be that big of a deal (per models) dumped good accumulating snow fall amounts from Lubbock to Wichita Falls and points in between. Also lots of snow flurry reports west of the Dallas metromess. Just this morning a buddy of mine hunting outside of Junction couldn't get in his tree stand because of freezing rain. Lots of reports of a mixed bag of frozen precip out that way extending into the Austin area.

So what does next week bring? I think a colder and deeper arctic airmass than what is currently being forecasted with snow breaking out across central and north Texas maybe reaching into the northern sections of southeast Texas. Other areas will experience a mixed bag of wintry weather. Interesting times ahead. Just my 2 cents.

[unome]

just for the record, if you look online at current local weather forecasts 7 days out from:

HGX http://www.srh.noaa.gov/hgx/?mystation=KIAH

KPRC http://houston.justweather.com/

KHOU http://www.khou.com/weather/

KTRK http://abc13.com/weather/

KRIV http://www.myfoxhouston.com/weather

KIAH http://cw39.com/weather/

there is not one that is forecasting temps for Houston below freezing on their official website forecast at the moment

I realize forecasts can and do change, but at the moment, that's what they are putting out for the public view

[srainhoutx]

The Medium Range guidance continues to advertise a very strong Arctic air mass dropping S from the Canadian Prairies into much of the West and Plains. An anomalous 1060mb+ Arctic High with its origin from Northern Siberia continues to settled S across the North Pole and will drop into the Inter Mountain West and Central Plains early tomorrow and push further S spreading a very dense and shallow Arctic air mass deep into the Lower Colorado River Valley as well as the lee side of the Rockies into the Southern Plains into the NW Gulf Coast. This Arctic High is near or slightly below 3 standard deviations below normal for this time of year. The pattern coincides with a +PDO/-EPO Regime.

A very cold positive tilted upper trough will extend from Southern California/Southern Arizona where a cold core 5H low will wrap up into a closed core upper low after the Arctic air arrives into Brownsville and Houston on the 30th into early New Year’s Eve. As the cold core 5H low and trough begin to meander E, embedded short waves will ride NE from the Eastern Pacific setting the stage for warm air to overrun the shallow dense very cold air at the surface. This sort of pattern is a typical Winter Storm setup for extended periods of light freezing drizzle/freezing rain very far S along and N of the I-10 Corridor of Texas and heavy higher elevation snow across the Southern Rockies. This is a classic case of the operational numerical guidance under estimating the dense, shallow very cold air at the surface. We are witnessing all sort of issues from the current storm and much weaker forecasted cold air where sleet and freezing rain is falling this morning where nothing but a cold rain was forecast. The 700mb flow is expected to be easterly creating cold air damming and upslope snow across the Front Range of the Central and Southern Rockies that may extend into Kansas, Western Oklahoma, West Texas, and the Panhandle.

Depending of the eventual evolution of the close core upper low as it track E later next week, the potential is present for a major Ice Storm across the Southern half of Texas extending NE into the Tennessee Valley and possibly the Mid Atlantic. The wild card will be for any potential Coastal low/trough development near Brownsville New Year’s Day and moving NE. It will be interesting to see exactly how this potential Winter Storm develops as we end 2014 and ring in the New Year.

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[redneckweather]

Good post Srain. I'm thinking guidance will start showing more of a closed core low traversing the state after the the arctic front blows off the coast.

[srainhoutx]

After a nasty cold rainy Sunday where temperatures remained stuck near 39F to the low 40’s which busted big time from the highs near 50F expected, today will be a transitional day as the Arctic front currently located near the Nebraska/Kansas border begins to drop S. Fog has developed across area E of a Brenham/Sealy line and may take some time to scour out before partly cloudy skies arrive this afternoon…if then.

The much talked about Arctic front arrives tomorrow with its near 1060mb High pressure cell over Montana/Wyoming and the very cold upper trough out West continues to drop toward Southern California before closing off and forming a cold core upper Low near Las Vegas Tuesday morning. Very chilly temperatures across the West are expected and snow is likely in Las Vegas, just N of Phoenix into Tucson and very far S in Western New Mexico as the Arctic front spills E over the Eastern Mountain gaps of the New Mexico into the Rio Grande River High Plains. The Arctic high will settled into Western Kansas and modify to around 1045mb which gives us an idea of just how dense this Arctic air mass is. The front will clear the Texas Coast Tuesday afternoon/ evening with increasing cold air advection Tuesday night into New Year’s Eve.
The challenging part of the forecast for much of Texas begins in earnest New Year’s Eve afternoon as up glide and over running moisture from the Eastern Pacific begins to saturate the upper/mid levels. The worrisome forecasting challenge is what the short term meso guidance indicates Wednesday afternoon. Light precipitation breaks out along the Rio Grande as the closed upper low begins to slowly move E over Arizona. The GFS and ECMWF are a bit drier with the surface boundary versus the aggressive NAM/WRF/SREF meso guidance that suggest a couple of 100th of an inch of light drizzle or light rain breaks out across S Central Texas spreading ENE New Year’s Eve night. Those shorter range models also suggest that surface temperatures are just below freezing along and N of the I-35 Corridor from just N of San Antonio and Austin and just W of the Dallas/Ft Worth area. The 2 meter temperature profiles for SE Texas as near 34 to 36 degrees along and N of I-10. These temperature profiles at the surface may…big emphasis on may…might be too warm 72 plus hours out via the computer guidance. The NAM and SREF are suggesting an upper air disturbance arrives ahead of the main closed core upper low generating just enough lift to saturate the surface boundary during our New Year’s Eve festivities as we ring in the New Year. This continues into New Year’s Day. The next fly in the ointment is a Coastal wave developing Thursday night and just how close to the Coast a warm front actually makes it. The current thinking is the Coastal wave and warm from may remain just offshore, but warming temperatures are depicted by the guidance as the Arctic high weakens and retreats E. It is noteworthy that the computer models often are too quick to erode the cold air at the surface once it becomes entrenched, so we will need to monitor the trends the next couple of days. The most worrisome period in New Year’s Eve and early New Year’s Day at the moment. With so many forecasting challenges to a busy Holiday period, it is prudent to keep tabs on the weather closely later today and tomorrow into Wednesday before venturing out for a night of New Year’s Eve activities.

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12292014 03Z SREF Enesembles Mean PTYPE SREF_LIKELY__f072.gif

[tx_kingwood32]

Thank you steve! Glad to be apart of the board finally! Been reading since Dan Meador was still with us! Just never had the guys to sign up cuz I didn't wanna sound stupid hah

[snowman65]

I noticed that TWC has changed Austins (actually Spicewood where I will be) new years weather from straight rain to an ice/rain event and have lowered the high temps to 35ish....

[tx_kingwood32]

I wouldn't trust TWC a they have been known to bust BIG TIME

[srainhoutx]

Thank you steve! Glad to be apart of the board finally! Been reading since Dan Meador was still with us! Just never had the guys to sign up cuz I didn't wanna sound stupid hah

Welcome aboard. No need to worry. Many folks have learned a great deal about all things weather over the years from our weather community. Dan taught many to enjoy weather and we have carried on that tradition since Dan passed away. We still miss him terribly, but have continued the vision he had for the KHOU Board and have grown so much over the years. I know he is looking down and is very pleased we continued to grow and expand to a much more Gulf Coast Regional Board he dreamed of.

[tx_kingwood32]

Thank you steve! Glad to be apart of the board finally! Been reading since Dan Meador was still with us! Just never had the guys to sign up cuz I didn't wanna sound stupid hah

Welcome aboard. No need to worry. Many folks have learned a great deal about all things weather over the years from our weather community. Dan taught many to enjoy weather and we have carried on that tradition since Dan passed away. We still miss him terribly, but have continued the vision he had for the KHOU Board and have grown so much over the years. I know he is looking down and is very pleased we continued to grow and expand to a much more Gulf Coast Regional Board he dreamed of.

Well said my friend,well said!

[srainhoutx]

The Arctic boundary is pushing S rather quickly across Kansas at this hour.

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[srainhoutx]

Morning briefing from Jeff:

Arctic air mass heading for TX with another wet storm system Wed-Sat.

Big changes on the way this morning with arctic boundary surging through KS into northern OK. Upstream temperatures over NW KS are in the 1’s with the arctic boundary being driven by a massive 1055mb high pressure cell dropping out of NW Canada. Boundary will plow southward today especially across west TX as is common with such air masses and likely push into NE MX before reaching Houston as the cold dense air dams against the Rocky Mountains. Model guidance does not have a good handle on the incoming cold as is usually the case with shallow and very cold arctic fronts. Almost all the guidance is too warm and once again will need to significantly undercut the guidance output to match what in reality will likely occur.

Arctic boundary will move across SE TX on Tuesday and off the coast and temperatures will begin their fall from the 50’s into the 40’s. Cold air advection will continue into Wednesday and expect temperature to not warm much if at all from the 30’s on Wednesday under increasing clouds. WSW flow aloft from the downstream effect of a large upper level trough over the west coast will produce overrunning of warm and moist air on top of the dense and cold arctic surface pool. Short range models have a slightly better handle on the incoming air mass and will follow that guidance for Wednesday with highs mainly in the 30’s for most inland locations and the lower 40’s near the coast.

NYE Night:
Problems begin on Wednesday evening as lead short wave moves out of the SW US and across the arctic cold pool. Models have increased the chances for precipitation on Wednesday evening which is running about 12-18 hours faster than previous guidance was suggesting. Bigger concern is what will surface temperatures be at this time. Highs on Wednesday in the 35-38 range would only need to cool a few degrees to potentially lead to freezing drizzle or freezing rain. This seems at least possible NW of a line from Columbus to Brenham to Huntsville on Wednesday night where dewpoints in the upper 20’s would allow a few degrees of evaporational cooling to lower the surface temperature to near or below freezing. Main question is just how much precipitation actually develops and how well are the models handling the surface cold air as only a few degrees will make a big difference over portions of the area. For now will keep everything liquid SE of the above mentioned line which falls in close with WPC freezing rain probability guidance showing the highest threat along the I-35 corridor from San Antonio to Dallas. A lot of uncertainty in this part of the forecast and changes are likely over the next 48 hours.

New Year’s Day:
Increasing overrunning pattern with widespread light to moderate rainfall developing over the region with cold surface arctic high entrenched at the surface. Temperatures will show almost no recovery likely in the mid 30’s most of the day. Some locations north and west could be very near freezing during the morning hours and even into the afternoon hours and will have to continue to watch for freezing rain mainly NW of a line from Columbus to Huntsville. Will see temperatures attempt to warm slightly by evening as warm air advection attempt to gain ground, but think the models are too quick in eroding the cold air.

Friday:
Powerful upper level system approaches the region from the west with significant lift and moisture advection into the region. Expect widespread rain and thunderstorms. Surface temperatures should start to warm into the 40’s during the day on Friday effectively ending any threat of freezing precipitation. Thinking is that the warm sector will not push inland keeping any severe threat offshore, but will need to watch for this potential in the coming days. Potential for heavy rainfall will increase and given the wet grounds in place from the 3-8 inches of rainfall over the last 2 weeks rises on area rivers and watersheds will be possible.

Storm system exits on Saturday, but clouds and rainfall will likely linger into Saturday afternoon along with cold temperatures. May finally see the sun again by next Sunday with a warming trend.

[Portastorm]

I noticed that TWC has changed Austins (actually Spicewood where I will be) new years weather from straight rain to an ice/rain event and have lowered the high temps to 35ish....

And I believe you're going to see more of that trend ... to a point where the entire I-35 corridor north of I-10 is at threat for wintry precip Wed-Thurs. Temps will continue to be ramped down. We don't get 1050mb+ highs coming down the lee side of the Rockies into Texas and mid 30s for temps. Guidance is still too warm IMO.

[snowman65]

Right, I've already noticed a few degrees lower even this morning again.....