Good morning. Temperatures are bottoming out at 10 to 15 degrees across much of the metro area in what will be the region’s coldest night in more than three decades. The city’s official low temperature, measured at Bush Intercontinental Airport, looks to be 12 degrees.

Making matters worse today, power outages persist across the state, with more than 4.1 million customers without power. Many of these power outages are concentrated in and around the Houston area. Weather conditions will begin to slowly improve today, but there are no reliable estimates for when widespread power will be restored. We discussed why in a post on Monday.

Tuesday

Clearing skies and winds shifting to come from the east later today will help warm temperatures somewhat. Most areas south of Interstate 10 should reach above freezing later today, but road conditions are iffy this morning. Some streets dried out with Monday’s sunshine, but roads and bridges that remained wet iced over again on Monday night. Sunshine later this morning should help with most roadways later today.

However, precipitation will return this evening and overnight as moisture moves in from the Gulf of Mexico. Most likely the precipitation will begin around midnight, but we can’t rule out it starting earlier. For Houston, it should begin as rain, but could transition to freezing rain over night. North of a line from Matagorda to Houston to Winnie, we can probably expect temperatures to freeze tonight. Galveston and Brazoria counties, for the most part, are unlikely to rain transition to freezing rain as they will remain above 32 degrees.

Bottom line: Travel Tuesday evening and overnight in Houston and could be very problematic due to icy roads. For Montgomery County and points north accumulating freezing could be exceedingly dangerous, and pose problems for power lines.

Wednesday

By mid-morning Wednesday, or shortly thereafter, temperatures should rise above freezing across nearly all of the metro area, and this should melt ice. Highs in Houston will reach about 40 degrees, if not a touch warmer. Some additional sleet or light snow is possible Wednesday night, but this seems unlikely to be too problematic. Areas south of Interstate 10 are unlikely to freeze.

Thursday

The precipitation should end by late Wednesday night, setting the stage for a dry and cold Thursday, with highs near 40 degrees. Expect one more very cold night on Thursday night, with lows in the 20s. Fortunately, it will be dry,

Friday, Saturday, and Sunday

As high pressure comes to dominate our weather, expect sunny skies on Friday, with highs in the 40s, with temperatures reaching the 60s by the weekend. At last, our winter blast will be at an end. Not soon enough.

We again want to express our best wishes and thoughts for so many of our readers, Houstonians, and Texans who are outright suffering tonight because of the combination of a true “tail event” and who knows what else happened with the power grid (which I sincerely hope is transparently communicated to Texans in the days and weeks ahead). Please, if you’re one of the fortunate ones tonight, check on anyone you know that may not be so fortunate.

That said, we are a weather blog first and foremost and we want to let you know about a couple things: How tonight’s forecast is tracking and an update on Wednesday’s storm.

How cold tonight?

We’ve been asking this question for days when it was apparent that tonight would be the main event for cold. So, we have a lot of models and data and whatnot, but let’s actually compare to data from the most recent comparable event: December 1989. On December 23 and December 24, 1989, Houston (Bush Airport) hit 7° and 11° respectively, close analogs to what we believe tonight’s low temperature will be. One way to check on how things are going is to track the temperature at Bush Airport hour by hour and compare to the hourly observations in those events, as well as the NWS point forecast from just before 8 PM this evening.

Through 9 PM at least, we are coming up short of both nights from 1989 as well as the current forecast. All that said, it’s very early still, relatively speaking, and temperatures on nights like this can easily drop like a rock under the right conditions. So don’t read too much into what you see here just yet, but I felt this would be an interesting way of looking at things.

If you are unable to sleep or have too much time on your hands tonight (like me, probably) and you want to track our progress through the night, you can check out real-time IAH observations at this link.

(Editor’s note: Replace “IAH” in that link’s URL with whatever airport code you desire, if you’d like to track conditions at that location. Some local ideas? GLS for Galveston, HOU for Hobby, EFD for Ellington Field, LVJ for Pearland, SGR for Sugar Land, TME for the west side of Katy, DWH for Tomball, and CXO for Conroe. You must keep the “K” before those three letters though!)

Wednesday’s Storm

The National Weather Service has issued a Winter Storm Warning for Wednesday’s storm now.

Here’s what I can tell you confidently tonight:

• The precipitation will fall as either plain rain or freezing rain. Sleet or snow are unlikely in our area.
• Precipitation should break out around Midnight, give or take a few hours Tuesday night/Wednesday morning.

Exactly who sees freezing rain vs. plain rain? That’s the forecast challenge right now, as shallow, dense cold air is not always easy to dislodge. If we look at the HRRR model forecast for tomorrow evening at midnight, you can see roughly where it predicts the freezing line to be located.

This is essentially just north of US-59 to Houston and east along or just south of I-10 to Port Arthur. The European model and NAM model are slightly warmer than this, and the GFS model is very similar to the HRRR. All models show temperatures getting above freezing by mid-morning or so Wednesday across the entire region. Expect at least a few hours of freezing rain in Houston, with a longer duration as you go north. Total icing may be as much as a glaze to a tenth of an inch across Harris County, with higher amounts possible as you go north into northern Liberty and Montgomery Counties and even more from Walker County northward. For most of us this shouldn’t be a “power outage” issue, but rather a travel one. Expect travel to become difficult to impossible north of I-10 or US-59 after midnight Tuesday night, but we will likely see improvement from south to north after sunrise.

Things could change, but that’s what it looks like right now. We want you to be aware and be smart about this next storm, so that’s why we have this here. Eric will have more for you in the morning. But right now, just focus on getting through tonight. Our thoughts are with you. Please stay safe.

Millions of customers in the greater Houston region continue to experience some of our coldest weather in decades without the benefit of electricity to heat their homes. (Full disclosure, I am one of them, and have been since 2 am CT. I am typing this from my office, wearing a winter jacket).

To understand what is going on, and when the power might return, I spoke this afternoon with Kenny Mercado, CenterPoint Energy’s Executive Vice President for Electric Utility.

First, it is important to understand how power generation works in Texas. Power plants across the state generate electricity from natural gas, coal, wind, solar, and other sources. This is all put onto the grid, which is managed by the Electric Reliability Council of Texas. Then it is up to companies like CenterPoint to deliver electricity to your home through its network of lines and poles. (Reliant, the sponsor of Space City Weather, markets and sells electricity to the customer. They are not directly responsible for generation or delivery).

What happened

As of 2 pm on Monday, about 1.1 million of CenterPoint’s 2.6 million customers are without power in the greater Houston area. Mercado said customers without power are unlikely to get electricity back today, and quite possibly not tonight—when temperatures are forecast to reach near all-time record lows.

Two things happened last night to contribute to these outages. First, demand was extraordinarily high across the state, Mercado said. And then, beginning at about 1 am, generating units started to shut down. This is almost certainly due to extremely cold conditions. Eventually about one-third of the anticipated capacity went offline. This included a handful of freezing wind turbines, but the majority of the volume losses were due to coal and natural gas plants going offline.

CenterPoint had been planning to manage increased demand overnight and today through rolling outages, which would last about 30 to 45 minutes. However, when power plants began going offline, CenterPoint had to prioritize circuits that fed power to emergency units, such as hospitals and police stations. After this, there just was not enough capacity to implement rolling outages so if your power went out, it mostly stayed out. (Note: If you have power, do your part by conserving energy. If you use fewer watts, access to the grid can be expanded to others).

Although some small generating units are beginning to come back online, Mercado said demand for electricity will increase tonight as temperatures bottom out. Thus, he said, for those currently without power, “It’s pretty risky to assume the power will come back on tonight.” I realize that’s a pretty sobering statement.

Mercado said he is hopeful that decreased demand on Tuesday (statewide temperatures should be 10 to 15 degrees warmer) as well as more generating units returning will allow for power to be restored to more locations, if not all of the state.

Blame to go around

This obviously is a monumental screw-up by the state of Texas, ERCOT, and the companies responsible for power generation in Texas. Why was demand not better anticipated? How are generating plants rated for cold weather production? The list of questions goes on and on. There is plenty of blame to go around, as it seems likely that people will lose their lives due to cold, or medical needs for electricity.

Be wary of those quick to scapegoat wind turbines or any single government official or political sides for this failure. This is a failure of the whole government and a lack of sensible regulation of electricity generators. We need to learn from this mistake so that it is not repeated. After our teeth stop chattering, of course.

First off, our sympathies are with what we assume are large numbers of our readership without power today. We hope you get it restored soon, but the news has not exactly been great today.

But here is some relatively good news to get you started. As of this writing, both Bush and Hobby Airports are up to 22 degrees. With the sun out, we might be able to squeeze another couple degrees out of things today. That sun is also helping to melt some of the snow and ice on area roadways.

Crews are working on clearing roadways but these extreme temperatures will continue so slick conditions will continue as well. pic.twitter.com/BRSnHibUZK

— TxDOT- HOU District (@TxDOTHouston) February 15, 2021

While those roads are still difficult to impossible to traverse, we may restore a little road functionality today. However, after sunset and with temps plunging again tonight, any slush that is leftover on area roads (particularly on side streets in Houston and various area subdivisions) will refreeze into solid ice, making travel tonight virtually impossible, possibly even worse than this morning.

One other safety reminder: If area retention ponds or lakes in subdivisions begin to freeze over, while it will look neat, it will be exceptionally dangerous to attempt to walk on. Simply put: Admire from afar, and please make sure children stay away from them.

Our morning low at both Bush and Hobby was 17 degrees, which is the coldest we’ve registered since the December 1989 cold blast. And we may (probably) dip below that before midnight.

We’re also seeing a true rarity in Southeast Texas: Lake effect flurries and clouds.

Two distinct plumes are coming off Lake Livingston and Lake Sam Rayburn this afternoon and even Lake Conroe if you squint. You can also see a plume of “bay effect” clouds coming out of Galveston Bay and into the Gulf. This is why even with the sun out, it may have felt like you were living in a snow globe this morning.

Tonight

So how cold will it get tonight? Clear skies, diminishing winds, and a fresh layer of snow is a recipe for what we call “ideal radiational cooling.” Reliable model guidance tonight ranges from 10 to 17 degrees at IAH/Bush, and in an ideal radiational cooling situation like this, typically you’d subtract a couple more off that.

Add in that the models have generally been underdoing the intensity of the cold, and you have a forecast map like the one above from the National Weather Service. There may be some chance that we fall short of these numbers, but I would not be betting on that, and most of the area should expect lows of 5 to 15 degrees, coldest northwest, warmest southeast. Houston’s all-time record of 5° from 1930 is probably safe, but not by much and with little room for error. Either way, tonight promises to be a once in a generation type cold that will unfortunately cause a lot of damage to infrastructure, pipes, etc. We wish our readers the best.

Tuesday and beyond

Not much has changed in terms of what to expect the next couple days. More sunshine tomorrow should help further melt snow and ice on roads and most areas south of I-10 should get above freezing. North of I-10 is another matter, which plays into Wednesday’s outcome. We will continue to be honest that there is still a lot of uncertainty as to how much cold air will remain locked in over the area. Gulf air and onshore flow doesn’t typically have to compete with a snowpack here, so it creates a difficult forecast. What I think we can say for Houston: Most of the metro area should eventually see plain rain on Wednesday, with temperatures above freezing. Based on modeling, we are growing concerned about a very serious ice storm north of about Conroe up to just south of Dallas, but details will likely still be elusive until tomorrow.

With Eric still powerless, I’ll have one final brief update for you once more this around 8:30 or 9 PM. Stay safe, and try to stay warm everyone.