How does the forthcoming freeze compare to the Valentine’s Day Arctic blast of 2021?

Good morning. We are now a little more than two days out from an Arctic blast that will bring the Houston region its coldest weather since a deep freeze in February 2021. If you’ll recall, that freeze prompted widespread power outages across the metro area as power plants were taken offline due to improper winterization. For a lot of people, this was miserable. For a more than a few people, it was deadly.

This loss of power magnified a cold weather event that was already tremendously destructive to pipes and plants. State officials say they have addressed these winterization concerns at power plants, and lacking sufficient expertise we are taking them at their word. What we can say is that the magnitude of this Arctic air likely to be similar to February 2021, although not quite as deep or prolonged. It will provide a meaningful test of whether the state’s electric grid has, in fact, been hardened. We also do not anticipate in any snow, sleet, or freezing rain to complicate travels on area roadways.

The image below compares the hour-by-hour temperatures observed during the February 2021 freeze (blue line) with the current forecast for temperatures (white line) at Bush Intercontinental Airport from the National Weather Service.

Hour-by-hour temperature forecast for Dec. 22 to Dec. 25, overlaid over the February 2021 freeze. (Space City Weather)

Tuesday

There has not been much change to our overall thinking when it comes to the forecast. We will see mostly cloudy skies today, with highs in the mid-50s and modest northerly winds. Low temperatures on Tuesday night will drop into the mid-40s.

Wednesday

Conditions will be a lot like Tuesday, with similar highs. The only meaningful change is that winds will shift to come from the southeast by Wednesday night, with lows dropping into the upper 40s.

Thursday

The first half of Thursday will see a decent warmup, as the onshore flow starts to bring a southerly flow. Areas south of Interstate 10 may even briefly reach 70 degrees before the front barrels through during the afternoon and early evening hours. While we can’t rule out a few light showers, we don’t expect any impactful precipitation. We’re still looking at sharp temperature drops in the immediate aftermath of the front’s passage, and gusty winds to 35 or 40 mph. Conditions overnight into Friday morning will be extremely unpleasant.

This is probably a reasonable worst-case scenario for low temperatures on Friday morning in Houston. (Weather Bell)

Friday

Low temperatures will bottom out on Friday morning. How cold? There’s still some wiggle room on the details, but lows will likely reach 15 to 20 degrees inland of Interstate 10, with slightly warmer conditions in the metro area of 17 to 22 degrees, and lows in the low- to mid-20s closer to the coast. Although skies will be mostly sunny on Friday, highs will only warm to near freezing briefly, with blustery winds throughout the day. Overnight lows should be 2 to 5 degrees warmer on Friday night.

Saturday

Highs will climb to around 40 degrees on Christmas Eve, with mostly sunny skies. Travel for the holidays should be fine, with dry roadways. Lows on Saturday night will probably still drop into the mid-20s in Houston, with even colder conditions further inland.

Christmas Day

Look for mostly sunny skies, with highs in the low 40s on Christmas Day. Lows may drop to freezing, or just above, in Houston that night.

Next week

Expect a steady warming trend next week, with temperatures in the low 70s by Wednesday. After that? The crystal ball for New Years celebrations remains a bit hazy. Rain chances do appear low until late next week, at the earliest.

51 thoughts on “How does the forthcoming freeze compare to the Valentine’s Day Arctic blast of 2021?”

  1. Thanks for the always detailed forecast. Note to the citizens. Please keep in mind, power supply issues and interruption due to infrastructure damage are NOT the same thing. Just keep that in mind if something goes south. Lots of wind coming.

    • Exactly. I’m not really worried about grid-level issues like generation undersupply or rolling blackouts. I am concerned about a limb taking out a feeder or supply line near my house.

    • I expect there’ll be almost as many power issues due to wind, rather than grid, and that widespread water issues will probably still occur again too (due to low pressure since everyone will either be dripping pipes, or have some that burst, pretty much, causing low pressure cascades). Will it be as bad as Feb. 2021? Probably not. Is Christmas probably canceled for infrastructure reasons? Eh, I feel like it’s hard to rule that out. Why it happens doesn’t change much.

      Maybe I’ll be wrong, but after more than 40 years in Houston, I don’t see any reason to be optimistic.

  2. I love that you provide such a valuable information service to the Houston area utilizing science with concise and thoughtful journalism. I do think you missed the mark with, “for a few people it was deadly”. The official death count compiled by the state was 246 people (I’m aware that other counts place it higher), and that would put it up there with Hurricane Camille. I think that phrasing could have been worded with more empathy and awareness.

  3. Thank You for the clarity on this. I now live in Corpus Christi, TX thus I can add a few degrees to the HOU area lows. Great Job, as always!

  4. In the comparison graph, the white line starts warmer than the blue line. Could this affect the outcomes for people during the event?

    • I’m hoping the attic will be warmer when the front moves through and blocking the gable vents will retain the heat. Lately the attic has been 7-10 degrees warmer at sunrise than the outside (I have a remote temperature sensor in the attic).

    • With this level of cold, it won’t be a huge impact. It will impact the staying power of the cold (the ground takes quite a bit longer to cool), but it is still going to be bitterly cold in Houston terms. It would have a huge impact if there was any precipitation involved, but we’re lucky this time in that aspect.

  5. Here we go again……….dang!

    A few hours will be spent in the attic today repairing some damage to pipe insulation I noticed Saturday and plugging the gable vents. Then wake up every two hours or so Thursday night to purge the water in the pipes with fresh. But at least it’s not as bad as two years ago when I discovered the squirrels had gotten a third on my pipe insulation.

    I need to live somewhere where the homes and utilities are actually winterized. Where I grew up we didn’t have issues at -20F.

  6. My understanding of the 2021 debacle was the ice accumulation severely affected the ability of generating power from the wind turbines, along with the insufficient insulation at our power plants, caused the grid to fail across the state. It seems to me that this will be a wind and temperature event without the ice issue. Doesn’t that make a huge difference in our expectation that the grid will be able to handle this 3 to 4 day event?

    • The ice accumulation wasn’t as big of a deal as the overall lack of wind. There are MANY wind turbines in the upper plains, and they work fine with the weather up there. But if it is calm behind the blast (as 2021 was), wind turbines won’t spin. The colossal failure of both gas storage/transport and the power plants themselves is the core reason behind the grid’s failure.

      • Am I right in thinking that, compared to a freeze with ice and snow, wind turbines should not have a problem but gas pipelines that have not been winterized would be just as likely to freeze?

      • Yes, this is my understanding too. In 2021, because of calm conditions, ERCOT was planning on very little power from wind. The largest problems were failing to winterize fossil fuel producers, especially natural gas supplies and plants. One unit of the South Texas nuclear station had to be shut down because water intake lines froze. This caused blackouts, which compounded the problem because a lot of these facilities had not filled out a simple form to exempt crucial infrastructure (like pumping stations) from the electricity cuts. Hopefully they’ve got their acts together this time.

        It does not have to be like this. I don’t care what the temperature will be in Houston Friday morning, because I’ll be in Colorado, where it will be colder still. And nobody there will be worrying about whether the grid can hold up.

  7. I am trying not to freak out, but man, that’s hard. The seriousness of the tone here is scary. I understand it, though, and appreciate all your work. We’ll see if the grid fails or not.

  8. Thanks for this update! Would love for a plumber to offer an answer to the million dollar question – should we empty pipes or not? That graph looks too close to comfort for me, and the drip method was devastatingly unsuccessful in ‘21 (perhaps I just answered my own question!).

    • We dripped until the water supply failed us due to a loss of pressure. And then we turned off the water. We ended up having several clogged fixtures afterwards due to sediment in the old metal pipes settling after the water was turned off. That makes me wonder if turning it off is the best option. In 2021 we had only one minor pipe crack, caught early after we turned the water back on.

  9. What in the world happened yesterday with the rain? We were supposed to get an inch or so. I live between Cleveland and Coldspring, and we had over 6″ of rain! That, combined with the 6″ we got a few weeks ago, has filled my ponds to overflowing!

  10. Just read an article this morning that said Ercot is now saying they expect more power usage than capacity. Got the generator ready!

  11. I am actually looking forward to this – but I am also from Northern Colorado, and hate Houston summers. With that said, I personally expect more power issues, but because of the winds, and infrastructure issues being wind power to the cities.

    Also, remember… this arctic blast will be an absolute genocide to mosquitoes.

    • The skeeters will be back this spring but it will be a bit of a reprieve this winter. Ever go to Minnesota or Alaska in the summer? It’s ridiculous up there!

      • Alaskan mosquitoes don’t play – they can carry off small pets and young children after they suck the adults dry. I know it is only a reprieve, but it will be nice when we get our “false spring” and the early part of spring.

    • Same I hate how gross and hot it is here. And plot twist: I’m a local born and raised. Aside from the obvious negative implications of this type of weather, I’m loving the bitter cold for the sake of the bittle cold, especially after that dismal Swampy Christmas we had last year. This feels great and I welcome it.

  12. What time specifically do you believe the front will hit the Kingwood area? There’s a farmers market happening, and it’s going to be shut down early. Would 5:00 be sufficient for shutdown? Normally closest to 6:00

    • I think 4:43pm would be okay at the corner of North Park and Lake Houston Parkway, but you’re really being reckless if you push it much past 5:07pm at Kingwood Drive and Lake Hills Dr. 5:12pm near Hamblen Road is right out. Is that specific enough? I make no claims as to accuracy, but then again your question was perhaps a bit unreasonable.

  13. A significant difference is the lack of freezing rain & snow in this week’s forecast.

    In February 2021 only 600 megawatts of the 32,000 megawatts of wind generation was generating electricity due to ice buildup on their blades. The wind turbine blades don’t have de-icing heaters in Texas.
    Also most of the commercial solar generation installations were not making electricity because the panels were covered in ice & snow.

  14. I’ve got a vacant home in atascocita. It has heat (as long as the power stays on). Should I cut the water off at the street and open all the taps or is it better to leave water flowing at a trickle? Leaning towards the former since a leak could go for many hours before being detected.

    • I’m in a similar situation with a house on the market and I plan to shut it off. There’s no reason to risk it if you’re not there to need water and if you won’t be there to monitor.

    • If you’re going to visit the property, cut the water off entirel. Takes practically just as long to do and will save you the worry.

  15. I wish the graph had a horizontal line at the 32 degree mark so we could tell when the temps were below freezing.

  16. Can anyone answer how you handle a tank or tankless water heater if you plan to drain pipes? Should you turn those off as well / set to pilot?

    • We are draining ours. With uri our condensate trap (which I don’t think you can drain) froze and had to be replaced. So we are covering that.

  17. Euro, GFS, and NAM all seem to be raising their temp forecasts. What’s going on? Is there a chance of a whispers bust?

    • The CMC (Canadian model) and ICON (German model) actually went colder, and the 12km NAV model (that the NWS uses for local forecasting over 24 hours) still is forecasting upper teens/low 20s.

      Beyond this, many forecasters I’ve talked to know that the depth and speed of these arctic blasts tend to be underestimated by global models – and this blast is also being driven by an epic high pressure system, which adds another layer of uncertainty.

      Either way, its going to be cold (by Houston standards), and a few degrees up or down at this level doesn’t make a significant change in the big scheme of things.

  18. Actually, it makes a very big difference. Two multi hour segments below freezing are far easier to deal with than an unbroken multi day span…

    • 3 hours at 34F vs 3 hours at 32F makes close to zero difference when surfaces are frozen due to 15+ hours as low as 17F. If you think of it from a physics standpoint, things will freeze, there will be damage, and we should all be happy that we aren’t getting precip with this front.

  19. Does anyone have a good idea of what road conditions will be like by mid-day on Friday? Trying to decide if I should leave for south Texas early Thursday or wait for the worst of the cold to pass to make sure my pipes don’t burst

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