JANUARY 2018 - Seasonal WX Week/Pacific Front Saturday

[WWxHopeful]

Has the frontal boundary pushed through already?

[davidiowx]

Has the frontal boundary pushed through already?

No clue where you are, but if you’re in Houston, then no it hasn’t. The front is not here yet, and won’t be here until tomorrow.

[DoctorMu]

Has the frontal boundary pushed through already?

Almost. Cold air is steadily filtering in. The colder stuff is north of Hearne and Round Rock. Killeen is 38°F. Round Rock is 8°F warmer.

[DoctorMu]

Has the frontal boundary pushed through already?

No clue where you are, but if you’re in Houston, then no it hasn’t. The front is not here yet, and won’t be here until tomorrow.

[WWxHopeful]

Has the frontal boundary pushed through already?

No clue where you are, but if you’re in Houston, then no it hasn’t. The front is not here yet, and won’t be here until tomorrow.

I’m at the Harris/Montgomery Co. line north of Tomball. I’m confused by the current surface map https://weather.com/maps/currentusweather

It shows the front already here.

[jasons2k]

It's diffuse but already through. The lowest pressures are along the coast, and pressures at IAH, CXO, and UTS are rising now. It will take awhile for the colder air to filter in though.

[don]

Some of the mesoscale models are starting to look interesting for the system Monday, the Texas tech wrf even shows moisture moving close to the Houston metro fwiw. We'll have to see if they trend wetter over the next couple of days.

[Heat Miser]

Wouldn't surprise me one bit if a fly in the ointment popped up unexpectedly.

[srainhoutx]

Sunday morning briefing from Jeff:

Multiple nights of hard freezes likely over the region

Preparations for very cold conditions should be completed this morning

Damaging advective freeze likely tonight and again on Monday night with radiative freezes likely on Wednesday, Thursday, and Friday mornings

Hard Freeze Warning in effect for areas N of HWY 105 tonight into Monday morning….warning will be needed for nearly all areas Monday night.

Frontal boundary is moving across SE TX currently with arctic air mass lagging behind the boundary a few hours. Cold arctic air mass will start pouring into the region over the next few hours and then surge off the coast by early afternoon. Highs temperatures have already been recorded at most locations and temperatures will fall today and tonight. Winds will increase into the 10-15mph range today and remain elevated tonight driving wind chills into the 10’s tonight with only modest recovery into the upper 10’s or low 20’s during the day on Monday. Temperatures will fall below freezing tonight by 1000pm N of HWY 105 and across areas N of US 59 by 200am. Expect periods of drizzle to end prior to the freezing line moving into the area which should preclude any threat of freezing drizzle tonight. With continued strong north winds…this will be an advection freeze which can be very damaging to tender vegetation. Traditional methods of covering tender vegetation work well on radiative freezes where the skies are clear and the wind calm which allow ground heat to help warm under any coverings. This method is not as effective with strong winds that will rapidly remove the ground heat…so make sure any plant protective coverings are as secure as possible to trap as much ground heat as possible.

A mid level disturbance will move across SC TX on NYD and some of the meso models are suggesting some QPF will be generated by this system SW of Houston toward Matagorda Bay and across SC TX/the coastal bend. Extremely dry air will be moving into the region on Monday as the arctic cold dome deepens (dewpoints into the 1’s), but there may be just enough moisture and forcing to produce a band of precipitation from near San Antonio and Del Rio toward Jackson and Matagorda Counties. Model cross sections suggest the air mass will be cold enough for sleet as likely the primary P-type although surface temperatures will likely warm into the mid 30’s melting any IP on contact. For now will keep chances around 20% for a rain/sleet mixture around Matagorda Bay with better chances SW of that.

Last item will be very cold wind chills both Monday and Tuesday. Will likely need a Wind Chill Advisory for values in the 1’s and low 10’s on those days as wind continue with very cold surface temperatures. Limit outside exposure.

Preparations:

Preparations for a damaging freeze should be completed this morning before the arrival of the arctic front.

1) Cover and protect any outside faucet connectors and any exposed pipes including sprinkler systems and their backflow preventer portion

2) Tender tropical vegetation will need to be covered and protected and ensure proper measures to keep coverings secured in strong winds.

3) Pets and livestock should be prepared for an extended period of sub-freezing temperatures. Some livestock water supply sources may freeze.

4) Ensure quality heating of homes especially those damaged by Hurricane Harvey which may still lack insulation or persons currently residing in temporary housing which may not have standard heating conditions.

Forecast Low Temperatures Monday AM:

N of HWY 105: 24-26 (wind chills: 9-13)

N of I-10: 27-29 (wind chills: 12-17)

N of coast: 33-36 (wind chills: 18-22)

Forecast Low Temperatures Tuesday AM:

N of HWY 105: 18-22

N of US 59: 20-25

N of coast: 24-29

Coast: 30-33

Forecast Low Temperatures Wednesday AM:

N of HWY 105: 17-21

N of US 59: 19-24

N of coast: 24-27

Coast: 30-32

[don]

We'll need to watch the system Tuesday as models hint at a coastal trough trying to develop as the cold core moves over us, some of the models show the moisture hugging the coastline but the 12z Canadian is the most aggressive so far

[harp]

Yes, the CMC just put snow all across south La. Tuesday night into Wed. morning.

[don]

FWIW the UKMET is even more aggressive than the Canadian with precip moving as far north as northeast Texas from the coastal system that develops Tuesday/Wednesday

[Ptarmigan]

The December 7-8 snow event was not handled well by forecast models.

[harp]

The December 7-8 snow event was not handled well by forecast models.

If I recall, they UNDER estimated the snowfall. They always seem to.

[srainhoutx]

Getting a few peeks at the sun late this morning as some drier air and brief breaks in the clouds have pushed in from Arkansas.

[redneckweather]

It was 45 when I got up this morning and temp has actually risen to 48...figured it would be headed the other way.

Looks like we could be on a sleet pellet/flurry watch Monday night into Tuesday.

[MontgomeryCoWx]

It was 45 when I got up this morning and temp has actually risen to 48...figured it would be headed the other way.

Looks like we could be on a sleet pellet/flurry watch Monday night into Tuesday.

Colder Arctic push isn’t here yet..... looks like it just arrived in CS

[harp]

It was 45 when I got up this morning and temp has actually risen to 48...figured it would be headed the other way.

Looks like we could be on a sleet pellet/flurry watch Monday night into Tuesday.

Colder Arctic push isn’t here yet..... looks like it just arrived in CS

We are 39 here just west of New Orleans. This front is moving in weirdly.

[snowman65]

Are they sniffing out changes in the air moisture, etc for the next few days?

[DoctorMu]

The December 7-8 snow event was not handled well by forecast models.

If I recall, they UNDER estimated the snowfall. They always seem to.

College Station prediction was 0 inches. We got 5 in instead.

Wintry mischief could occur near the coast. Unfortunately, it won't be snow...although it could be a mix of snow, sleet, rain and the air will be too dry north of 105.