February 2021: Arctic Outbreak/Warmup Begins

[MontgomeryCoWx]

The HRRR has a very sharp gradient. It all depends on where the freeze line sets up. My dew point is still 19 - I think that will be a factor as precip starts to fall, the temp should drop.

You and I are going to get it. 59 may not be too bad.

[srainhoutx]

Tuesday evening weather briefing from Jeff:

Winter Storm Warning in effect along and north of US 59 through tonight

Cold temperatures especially at night will continue to result in infrastructure and human hardships

Hard freeze likely Friday morning

Discussion:

Coastal low is forming south of Matagorda Bay and will progress NE across our coastal waters tonight into Wednesday. This will result in a quick return of moisture into the slowly modifying arctic cold dome over the region. Current dewpoints remain very low across the region and with surface temperatures in the low to mid 30’s, as light drizzle and rainfall begins to fall, temperatures will fall and dewpoints will rise. This will result in the freezing line along and north of a line from roughly Matagorda Bay to Wharton to Pearland to Winnie. During the night this freezing line will begin to move northward slowly as warmer air from the Gulf of Mexico attempts to move inland. How far north this freezing line progresses is important as to what areas receive freezing rain and ice accumulation and what areas see plain rain.

Current thinking is that the freezing line will slowly progress northward through the morning hours on Wednesday with freezing rain and ice transitioning to rain. Expect the greatest ice accumulations to be found along and north of US 59/I-10 where temperatures will remain colder for the longest period of time.

Minor ice accumulations will be possible generally south of US 59 with accumulations of .10 to .25 of an inch generally north of US 59. Isolated amounts of .25-.50 will be possible mainly far to the north of Houston where a devastating ice storm is looking likely.

These ice accumulations will likely result in some tree damage and power line damage over the region and hamper efforts to restore power generation.

Temperatures on Wednesday after mid to late morning will rise above freezing and any ice should begin to melt. Temperatures will fall below freezing again Wednesday night and Thursday morning and any water left on roadways will likely freeze again.

One final disturbance will cross the area early Thursday and there may be some light precipitation and will need to keep an eye on this feature on the next 24 hours. As this disturbance passes, another shot of cold arctic air will spread into the region resulting in another night of very cold temperatures on Friday morning where temperatures will likely fall into the upper 10’s to mid-20’s yet again over the area.

[srainhoutx]

Boil Water Notice issued for Pasadena due to pressure issues with the City of Houston Water Purification Plant on Genoa Redbluff.

[jasons2k]

The HRRR has a very sharp gradient. It all depends on where the freeze line sets up. My dew point is still 19 - I think that will be a factor as precip starts to fall, the temp should drop.

You and I are going to get it. 59 may not be too bad.

Several runs had trended a tad north, with a sharper gradient. The latest run had the sharp gradient, but it has nudged back south again. Lots of ice coming.

[don]

Most of the system is expected to move out by late morning,so this is mainly an overnight event,by the time we reach our high tomorrow the system will be out of here. And any ice accumulations should melt.The problem is more about how long does it take for the freezing line to move north overnight as warm air advection kicks in from the low.For northern counties the freezing line may never reach them unfortunately before the rainfall ends.While at this time for the central counties models show the temperatures getting above freezing once the heaviest rain starts,hopefully that happens or there will be significant accumulations of ice even for the central counties.

[jasons2k]

It's gonna be close. One of those situations where one-degree of difference will be huge, and within a matter of miles it will go from relatively normal to a total mess. The trend in the dewpoint is the key. That dewpoint temp tonight will be critical.

[MontgomeryCoWx]

It's gonna be close. One of those situations where one-degree of difference will be huge, and within a matter of miles it will go from relatively normal to a total mess. The trend in the dewpoint is the key. That dewpoint temp tonight will be critical.

Yep, that gradient I think will set up around Katy to Jersey Village to Humble.

[jasons2k]

It's gonna be close. One of those situations where one-degree of difference will be huge, and within a matter of miles it will go from relatively normal to a total mess. The trend in the dewpoint is the key. That dewpoint temp tonight will be critical.

Yep, that gradient I think will set up around Katy to Jersey Village to Humble.

I think that's a good call...and the difference on either side will be night and day.

[jerryh421]

What do we think of the last disturbance coming through? Would that be more of sleet/snow?

[jasons2k]

What do we think of the last disturbance coming through? Would that be more of sleet/snow?

Yes, but not much, a parting shot to end the winter.

[don]

Im not sure if its reaching the ground yet,but freezing drizzle looks to be already developing on radar.

[jasons2k]

Im not sure if its reaching the ground yet,but freezing drizzle looks to be already developing on radar.

Yeah, I see it. Don't think it is yet. mPing reports are still blank, just one report in Corpus of drizzle.

[Scott747]

Well the warm air advection better start kicking in. Temp was 5 degrees below the projection today and I'm already at 32.

[MontgomeryCoWx]

0z HRRR brings heavy ice to MoCo and NW Harris.

THEN. .... snow Thursday morning thru lunch including Harris proper

Temps won’t warm much at all if that precip verifies

[TXWeatherMan]

0z HRRR brings heavy ice to MoCo and NW Harris.

THEN. .... snow Thursday morning thru lunch including Harris proper

Temps won’t warm much at all if that precip verifies

Yep, it looks more aggressive with moisture Thursday morning

[tsb2107]

0z HRRR brings heavy ice to MoCo and NW Harris.

THEN. .... snow Thursday morning thru lunch including Harris proper

Temps won’t warm much at all if that precip verifies

Can you post model?

[don]

Yep Ive noticed also models are coming in more potent with Thursdays system,maybe another decent round of snow?Good news is since this system is coming with the upper level trough the setup looks like it could be maybe an all snow event,as the 540 line is much further to the south.

[jasons2k]

Wouldn't it be funny, if, after all this, it was the Thursday system that finally gave us the convective banding of snow we all hoped for on Sunday night?

[don]

Wouldn't it be funny, if, after all this, it was the Thursday system that finally gave us the convective banding of snow we all hoped for on Sunday night?

LOL i was thinking the same thing.That it would be funny if the Thursday system gave us more snow than the storm on Sunday/Monday.

[megsy]

Wouldn't it be funny, if, after all this, it was the Thursday system that finally gave us the convective banding of snow we all hoped for on Sunday night?

LOL i was thinking the same thing.That it would be funny if the Thursday system gave us more snow than the storm on Sunday/Monday.

It would be totally bonkers.