In brief: In today’s post we dive into the latest data about the impending winter storm and share our thoughts about freezing rain, hard freezes, and more in Houston. There is also a new wrinkle, with the potential for thunderstorms on Saturday morning. Because, why not?

Winter Storm overview

We continue to monitor the impacts from an Arctic front that will arrive this weekend in the Houston region. Friday and Saturday should be fine for getting around, although in a new wrinkle we now anticipate the potential for some thunderstorms on Saturday morning. Fortunately this will fall just as rain. We are still watching closely for when temperatures reach the freezing mark in the metro area, as that will make all the difference as to whether we see freezing rain and icy roads on Sunday morning. See below for a full discussion of all this.

Friday

We are seeing plenty of fog across the area this morning, with light winds, and temperatures and dewpoints both settling at about 60 degrees. Highs today will push into the upper 60s, with mostly cloudy skies. We could see a few light showers, but these should be nothing to write home about. Lows tonight should drop into the 50s, area-wide, as the initial push of colder air arrives from the cold front.

Saturday

There’s a new threat to talk about on Saturday. There will be an interesting setup with very moist, and warm air offshore and much colder air over inland parts of Texas. This could well lead to the development of some thunderstorms during the mid-morning hours on Saturday, as essentially a line of storms pushes through. This is likely to drop 0.5 to 1.0 inch of rain pretty quickly, and I hope the city’s efforts to treat bridges and overpasses for ice (which may come later) takes this rainfall into account. With temperatures likely around 50 degrees in Houston on Saturday, this will indeed just fall as rain.

After these showers and storms move through, we could see an end to precipitation for awhile on Saturday afternoon, although our skies will remain mostly cloudy. Temperatures likely will hover in the 40s during the afternoon hours, with modest northerly winds. At some point on Saturday evening to Saturday night, freezing temperatures will start to get closer to the area. They could arrive in Montgomery County by around 9 pm to midnight, and likely not moving into Harris and counties closer to the coast until after midnight or later. I expect area roadways to remain passable, at the very least, through Saturday evening.

Sunday

Ahh, Sunday. This day remains the bane of a forecaster’s existence. We really need to know precise temperatures throughout the day, literally to within a degree, and as of yet we still don’t have that kind of certainty.

With that said, I expect to see additional light showers overnight on Saturday into Sunday, followed by what may be a second line of showers and thunderstorms around sunrise on Sunday, or shortly thereafter. And then the rain should exit to our east, for good.

Question no. 1 is: How cold with temperatures be across the metro area at sunrise on Sunday? If they’re below freezing at your location, there’s a decent chance of some minor ice accumulation. If they’re above freezing at your location, it’s just very cold rain. I think there’s about a 50 percent chance of freezing temperatures in a location such as The Woodlands at this time, and perhaps less than 50 percent along the I-10 corridor in Houston, and less still south of there. So when you wake up on Sunday and consider going out and about, you’re going to need to be weather aware. Check local temperatures. See if the precipitation has moved on. Read what we’re saying here. Roads on Sunday morning may be fine. They may be mostly OK with some issues on elevated surfaces. Or it may be pretty icy out there and you should stay inside.

For now our best guess (emphasis on guess) is this: There could be up to 0.2 inch of ice accumulation in Montgomery County, especially along and north of Highway 105. Ares of northwest Harris County, as well as Waller and Austin counties, may see some minor ice accumulations. Areas closer to the coast probably will not.

Question no. 2 is: How warm will temperatures get on Sunday afternoon? As precipitation exits to the east, we should see some partially clearing skies on Sunday. With gusty northwesterly winds (perhaps up to 25 mph from the north) we are going to see a lot of very cold air advecting in. If temperatures are above freezing in your location for a couple of hours, with a little sunshine and these winds, we are going to see good conditions to dry out roads. However, if temperatures remain at or below freezing at your location, any ice is going to stick around. My general guess is that we are going to see roads dry out, at least in non-shadowed areas. But an alternative possibility is that we don’t get enough heat or sunlight before frigid temperatures descend Sunday evening. Again this is going to have to be a game time decision.

We remain highly confident in temperatures plunging on Sunday night, probably down to the 20-25 degree range in urban Houston, with conditions a little warmer closer to the coast, and a little cooler in places like Katy and The Woodlands (15 to 25 degrees). Note there still is some uncertainty about how cold it will get.

Monday

What roads look like on Monday morning will depend on what they looked like Sunday evening. We are not going to see any additional precipitation, so if they’re dry on Sunday night, they’ll be dry on Monday morning. We should see temperatures climb to highs between 35 and 40 degrees on Monday, and with clear skies and light winds, we can expect another very cold night. Temperatures likely only be 1 to 3 degrees above conditions on Sunday night.

Tuesday and beyond

We’ll warm up a little next week, likely with highs in the 50s and lows in the 30s until Thursday or Friday. After that time there’s the potential for a secondary Arctic blast, although I don’t think the overall airmass is going to be quite as cold this time. However there is also a non-zero chance of some snow with this system. But it’s all pretty fuzzy, and the models are hopping around a lot from run-to-run. So we’re not going to speculate too much here.

Our next update will be posted by or before 3 pm CT today.

A message from Reliant

If you’re new to our website, welcome. We recently celebrated the tenth anniversary of Space City Weather, and have always been—and always will be—free and freely available with no paywalls. We do not track our readers or collect their personal information. This is possible because of our readers who contribute to our annual fundraiser, and our long-time sponsor, Reliant. They have been our valued partner since 2017, and have helped us grow over that time. Today they want to offer a few tips to help you stay warm and manage electricity usage during upcoming freeze.

Try space heaters in high-traffic rooms. Lower your thermostat and use an energy-efficient space heater in rooms where you spend the most time.

Check your thermostat. If you have an electric heater, set the thermostat to 68 degrees while you’re awake. Lower it and add an extra blanket while you sleep to save energy.

Use your drapes. Thermal drapes can help block drafts and retain heat, especially on older windows. Open south-facing curtains during the day to let in sunlight and close them at night to trap warmth.

Invest in smart plugs and smart power strips. These allow you to control the power supply to devices remotely via a smartphone app. This way, you can easily shut off power to devices not in use, even when you’re not at home.

Layer up. Reach for a sweater or blanket before reaching for the thermostat. Weather-appropriate clothes help reduce the demand for heat. Plug in your electric blanket and stay warm for around 25 cents a day.

Install insulation. While more of a long-term project, you can regulate your home’s temperature and reduce heating costs by adding insulation.

Weatherstrip exterior doors and windows. With a couple of hours’ work, you can seal out the cold and save up to 10 percent on total energy costs.

In brief: In this afternoon’s post we discuss what we think will happen in Houston and surrounding counties with the forthcoming winter weather, and when it will happen. We also have some advice for people making closure decisions, and an opportunity for you to ask questions later today.

Ask me anything today

We’ve gotten a ton of questions, as you might imagine, about impacts from the freeze, and what it means for getting around Houston and traveling beyond the city this weekend. I’m going to set aside some time, beginning at 4 pm CT today, to answer your questions on Facebook. I’ll create a post and take your questions there. If you don’t use Facebook, don’t worry. We’ll collect some of the best and most-asked questions and repost them here on Space City Weather.

Wait to make closure decisions, if you can

We’ve also heard from business and other entities making decisions about closing on Monday. I fully recognize that everyone has their own timeline, and prefers to give people as much time to make accommodations. All I would really like to say here is that if you can wait to make a decision, it is probably in your best interest to do so. There are scenarios in which the “winter storm” this weekend has relatively modest impacts on the region and our roads. There are also scenarios in which the ice accumulation is enough to shut things down on Sunday and Monday morning. What we’re struggling with as meteorologists is just how crippling the impacts will be. Right now Matt and I are leaning slightly toward “modest” rather than “crippling” impacts, but it us just too early to say for sure. Anyway, if you need to make a decision today, you should err on the side of caution. If you can wait another day or two, you may benefit from better weather information.

Winter storm forecast

The forecast, as we’ve outlined for the last 24 hours, remains more or less on track. So for this afternoon’s post I thought I would do a post about what to expect, and when.

Friday, Friday night, and Saturday

This period should be moderately warm, with increasing rain chances on Friday evening and for much of Saturday. Although the cold front will arrive on Friday, it is going to take a secondary push before the Arctic air really pushes in. So on Friday we can generally expect temperatures in the 60s, with overnight lows in the 50s, and then temperatures in the 50s (perhaps 60s closer to the coast) on Saturday. This means that, when the majority of precipitation falls on Saturday, it’s going to just fall harmlessly as rain. That’s great.

Saturday night and Sunday

That secondary push of colder air will arrive sometime on Saturday night. We think it will arrive late enough such that getting around Harris County should pose no problems through at least 9 pm CT on Saturday. (This deadline may come a little earlier in Montgomery County, where temperatures will be quicker to reach freezing level). After this point we’re not quite sure how cold it will get, and how quickly. Let’s quickly go over two scenarios:

Slower Freeze: There is a world in which air temperatures on Sunday remain in the 33 to 40 degree range in Harris County and other parts of suburban Houston (outside of Montgomery County). At the same time we would see the end of showers on Sunday, and some sunshine during the afternoon to help dry out roads. In this scenario mobility issues on Sunday and Monday morning are mostly ok, although we would definitely have some concerns about bridges and overpasses.

Faster Freeze: In this scenario daytime temperatures drop to freezing during the daytime Sunday in Houston and surrounding areas, and we continue to see precipitation that falls as freezing rain. This accumulates on Sunday afternoon and there is no time for it to melt or evaporate before a hard freeze Sunday night. In this case driving around Houston on Sunday, Sunday night, and Monday is rather hazardous.

So which will happen? We just cannot predict with any confidence right now. Sorry. The European model and some of our emerging high-resolution guidance support the “slower freeze” scenario, but there is plenty of data to support a “faster freeze” scenario as well. Hopefully things will clarify in the next day or so, but no promises there.

Sunday night into Monday

It’s gonna get really cold on Sunday night, with temperatures likely falling to the 20 to 24 degree range in urban Houston, with colder conditions for outlying areas. This meets the criteria for a hard freeze, so all steps should be taken to protect pipes, plants, and pets. We continue to be hopeful that Monday will be sunny and see temperatures in the upper 30s to 40 degrees, which should solve ice issues on roads in Houston. What I’m not sure about is how far north these “above-freezing” temperatures will extend. For example, will ice melt from roads in Conroe or Huntsville on Monday afternoon? I’m not sure.

What about another ‘winter storm’ next week?

Yes, there is some possibility of another Arctic outbreak during the Friday, Saturday, and Sunday period of next week. Everything from snow on down is on the table. At this point it doesn’t look like absolute air temperatures will get as cold as this weekend, but we’ll just have to wait and see. One disaster at a time, y’all!

We’ll have an update this evening with the best questions and answers from our “Ask me Anything” this afternoon.

In brief: In today’s post we discuss the likelihood of Saturday being fine to get out and about in Houston, and whether that is likely to change on Sunday. We also have some thoughts for people driving north on I-45 and west on I-10 this weekend.

Big picture on the winter storm

Not much has changed overnight with the forecast for this weekend. A strong Arctic front will arrive in the region on Friday or Friday night, but it still appears that coldest air behind this front will only gradually spill into the Houston region. Therefore, if you’re planning to remain in the Houston metro area (i.e. from The Woodlands to Galveston, and Katy to Baytown) you should be able to go about your activities as normal throughout the daytime Saturday. I think roadway conditions will also be fine on Saturday evening, prior to 9 pm at least, but we’ll have to see.

Sunday is now the greater concern as this is when the colder air will arrive in Houston. The question, as we’ve been talking about for a few days now, is the timing of the colder air’s arrival and the end of widespread, light showers. I think there’s a decent chance that showers and freezing temperatures overlap on Sunday morning, in which case roads become icy and dangerous to drive on. Whether this occurs on bridges and overpasses only, or a majority of roads remains to be seen. But you should be prepared for disruptions, especially along and north of Interstate 10.

Our coldest temperatures will descend into the region on Sunday night into Monday morning, when there will be a hard freeze across the region. Whether roads remain icy during this period will depend on the amount of precipitation, afternoon temperatures on Sunday, sunshine later on Sunday, and a host of other factors I just cannot predict. But there is the distinct possibility of ice on roads through Monday morning. We’ll see.

What if I need to drive north on I-45?

There must be a lot of cheer competitions in the Dallas area this weekend because I have received an extraordinary number of questions about participants. I wish you all well, if the competitions proceed. My sense is that travel north all the way to Dallas should be fine on Friday and Friday afternoon. At some point on Friday night, maybe sunset, maybe 9 pm, maybe midnight, rain will start to transition to sleet or freezing rain in the Dallas-Fort Worth metro area. After that temperatures will remain below freezing through at least Monday morning, and perhaps all the way to Tuesday. Roads in the region up there will likely range from hazardous to borderline impassable for the weekend.

What if I need to drive west on I-10?

You have a little more time if you’re headed west. Driving along I-10 should be fine on Saturday, and likely into Saturday evening. But again, at some point Saturday evening or Saturday night there will likely be a transition to freezing rain that will last into Sunday morning. I would imagine that driving back from Austin or San Antonio will be fine on Monday afternoon.

What if I live north of Houston, in the Piney Woods or College Station?

For locations on the northern fringes of the Houston metro area, basically along and north of Highway 105, you can expect freezing temperatures to remain in place from Saturday afternoon through at least Monday, and possibly into Tuesday morning. This means any freezing rain or ice that accumulates on Saturday and Sunday will likely remain in place for awhile. I expect travel around these areas to be very difficult starting on Saturday and you should prepare to hunker down for a couple of days.

Thursday

It won’t feel like winter today. Thanks in part to warm, humid air and yesterday’s rains we are seeing fairly widespread fog this morning. After this clears we will see partly sunny skies this afternoon, and a warm day with temperatures in the lower 70s. Winds will be light, generally from the east. There is a very slight chance of showers near the coast. Lows tonight will only drop to about 60 degrees. It’s a good day for winter storm preparations.

Friday

This will be another fairly warm and humid day, to start. Expect highs to reach the upper 60s. We may see some very light showers during the daytime, ahead of the front, which should arrive on Friday afternoon or evening. As noted above the initial push of cooler and drier air into Houston will not be the main event. Lows on Friday night will likely drop into the upper 40s or lower 50s, with additional light showers.

Saturday

This will be a rainy and cold day. Expect widespread showers. Overall, I expect most areas to pick up about one inch of rain, give or take. The majority of this will fall as cold rain in Houston, rather than freezing precipitation. Highs on Saturday will likely top out in the 50s before a surge of colder air arrives later on Saturday and into Saturday night. We continue to think it should be OK to move around the Houston area on Saturday, with temperatures remaining above freezing. That could begin to change Saturday night, but perhaps not until after midnight for most locations.

Sunday and Monday

This will be the coldest period. I don’t feel particularly comfortable predicting highs on Sunday because they will be influenced by a number of factors, including clearing skies on Sunday afternoon, the influence of ice on the ground north of the Houston metro area (northerly winds chilled by this ice are not well modeled), and other factors. Generally, I think there is a decent chance that Houston’s highs reach above freezing for a couple of hours on Sunday, and if this happens in conjunction with clearing skies we could see most roads dry out. That’s the glass half full scenario. It is also possible that light rains linger into Sunday afternoon, temperatures remain at about the freezing level, and ice persists on roads through Monday morning. It’s going to be a close call in Houston. Anyway, we are highly confident in a cold night on Sunday into Monday (see image above), with lows in the hard freeze range necessitating the protection of pipes, plants, and pets. Temperatures on Monday should push at least into the upper 30s, and in conjunction with clearing skies this should end the threat of ice on roads. Lows on Monday night will be very cold again, although perhaps a couple of degrees warmer than Sunday night.

Next week

We should get into the 50s or perhaps lower 60s for a few days next week, but there is the potential for another front by Friday or so that could return freeze chances into Houston. We’ll see.

Our next update will be posted by around 3 pm CT today.