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.

In brief: In this afternoon update we talk about how the Arctic air may be arriving a little later than expected, and what that means for potentially icy roads this weekend.

Setting some expectations

Good afternoon. We are going to continue with twice-daily updates this week due to the interest in, and potential severity of, a winter storm this weekend. Before getting to that, however, I just want to note the nice amount of rainfall that fell over much of the region today. Most locations received 0.5 to 1.0 inch of rain, which was above expectations. Although this won’t spell the end of our region’s drought, a little bit of rainfall goes a long way in January. And as you may have heard, we have more precipitation on the way this weekend.

I also want to take a moment to set expectations. There has been some talk comparing the upcoming Arctic blast to the extremely cold winter storm in February 2021. I just want to say we are not anticipating temperatures nearly that cold (if you recall, low temperatures across the region in 2021 ranged from about 5 to 15 degrees Fahrenheit). Nor is the cold expected to last as long. Although this winter storm has the potential to be impactful, it will be of shorter duration. So yes, we should all be prepared for inconveniences, but I don’t expect total bedlam this time around.

You have questions about electricity and travel. We don’t have all the answers. What I can tell you is that ERCOT expects to have ample power generation during the coldest weather on Sunday and Monday. Locally, in terms of transmission, CenterPoint says it is well prepared to respond to outages, and is testing and hardening equipment. Hopefully that is the case. With regard to travel, we don’t know much more. In terms of flights, I think getting into and out of Houston airports will be fine on Friday and Saturday, but we do have some concerns about Sunday and Monday. We’ll see.

When is this mess getting here?

The one trend we’ve observed over the last day or so is a delay in the arrival of really cold air in Houston. With the caveat that all of this could still change, I now think we will see temperatures well above freezing in Houston (and surrounding counties) for much of Saturday. I would go so far as to say, tentatively, that it should be fine to move around the region through at least 9 pm CT on Saturday, and possibly a little later.

We are probably looking at plenty of rain on Saturday, but with temperatures at least in the 40s (or warmer), it will just be rain. However by later on Saturday night, and into Sunday morning, my expectation is that temperatures will begin to freeze. This will occur initially north of Houston, in Montgomery County, and then spread south into the city and down toward the coast.

Is there going to be freezing rain in Houston?

We still don’t have answers to this question yet. There is a chance that, with the somewhat slower arrival of the coldest air, the precipitation will have exited to the east by the time freezing temperatures arrive in Houston. That is one scenario. Another is that temperatures plunge after midnight, with rain showers persisting into Sunday morning. In this case we would see freezing rain accumulations on area roadways on Sunday. Right now I don’t have high confidence in either scenario. However, I think we need to be wary of the fact that, regardless of when the rain ends, there will be moisture on roads after the rains on Saturday, and this could freeze rapidly. Bottom line: The roads on Sunday morning could be pretty messy. We cannot yet say for sure what will happen. We will probably have a better idea tomorrow.

How cold is it going to get?

Despite the delayed onset of cold air, it unfortunately is still on the way. It now appears that Sunday, Monday, and Tuesday mornings will all bring the potential for a hard freeze. I think the coldest night will be Sunday night into Monday morning, when temperatures could drop into the upper teens in parts of Houston, and lower 20s closer to the coast. This hard freeze will necessitate care for outdoor plants, pipes, and of course pets. Please bring them inside on these extremely cold nights.

Really, Eric, do you think Houston is going to shut down due to ice?

I honestly don’t know. I want to emphasize that. But I will share what I am thinking at this moment.

I spoke above about different scenarios. The European model, of late, has been most aggressive about delaying the onset of colder temperatures. It effectively has the rain out of here by around sunrise on Sunday, and then has high temperatures getting into the upper 30s for most of the region on Sunday afternoon. In this case I’m reasonably confident that roads would be mostly dry for the hard freeze on Sunday night. In such a world it would be extremely cold, but the roads are mostly OK to drive on for most, if not all of the weekend and early next week. (The story, of course, should be vastly different north of Houston, toward Dallas; and west, toward Austin). There is also a world in which the colder air arrives earlier, before the rain departs, and we get a few tenths of an inch of ice on Houston’s roads. Then Sunday’s highs remain near freezing, and we remain ice-bound until the middle of the day on Monday. I really don’t know what will happen, but when we know more, we certainly will share that.

Our next update will be posted by 7 am CT on Thursday.