Matt Lanza

Summary: A hard freeze is likely north of Houston tonight, while much of the area sees 20s for lows. A light freeze is possible tomorrow night before we warm up. Next week’s rain chances are coming into better focus, with Monday and perhaps Wednesday seeing the most rain, but chances persisting all week long. Localized flooding is something we’ll be watching for, but we’re hopeful the rain is spread out over a long enough period to avoid anything too serious. We’ll have another update on this by Sunday.

Today & Saturday

We’re back at it today, with gusty winds and chilly temperatures, as a second plunge of cold air descends on Texas. This one is much more moderate than the one we saw earlier this week, but still after yesterday’s mid-60s, today’s blustery 40s will feel cold. But, we have the sun, so that counts for something. Winds will be 15 to 25 mph, with gusts to 30 mph, stronger over the water.

In terms of tonight’s freeze, as winds settle and skies remain clear, temps should drop efficiently into the 20s virtually everywhere away from the coast. For the city of Houston and most areas south or east, this will be a light freeze. Northern and western outlying areas are at risk for a brief hard freeze tonight, with lows expected in the mid-20s for The Woodlands, Conroe*, and Brenham. (*Conroe is always an interesting case given that they consistently record the coldest temps in the region, likely due to the location of the airport. So it’s possible they dip into the upper teens tonight)

This will still be about 6 to 10 degrees milder than the hard freeze earlier this week but certainly still capable of hazards to exposed plants (and pets).

Saturday will be breezy and chilly but a little less harsh than Friday. We should see highs in the mid to upper-40s with breezes of 10 to 15 mph or a bit gustier at times. Expect sunshine as well.

Sunday

Expect one more risk of a freeze Sunday morning, mainly north and northeast of Houston. A hard freeze is unlikely anywhere in our area. We will see increasing clouds with a chance of a few showers as early as Sunday afternoon, as high temperatures slow-climb into the low-50s (40s again north).

Next week

The rain we expect next week continues to show up in the forecast rather substantially. We’re starting to hone in on when the worst of it may be now. It looks like we have one pretty strong disturbance that moves through the area on Monday, which should mean numerous to widespread showers and thunderstorms.

This could deliver us anywhere from 1 to 4 inches of rain, and locally higher amounts can’t be ruled out. I would probably say the highest totals may fall to the south and east of Houston, but that is a very low confidence forecast call right now.

Tuesday should see isolated to scattered showers and storms. Rainfall should be a bit more erratic here, with some places seeing a quarter-inch or less and others another 1 to 2 inches perhaps. Then Wednesday may see another strong disturbance with the potential for at least another 1 to 2 inches over a broad area, with higher amounts.

Additional shower chances will follow Thursday and Friday, but it’s tough to say what those look like right now. When all is said and done, the rainfall amounts will tally 3 to 8 inches by Thursday, with higher amounts possible.

Does this mean flooding? It may. With the ground rather firm after this week’s freeze and the subsequent one this weekend, a lot of this water will be quick to run off, which means ponding and street flooding are a good bet in the usual trouble spots. The hope is that the total rainfall will be spread out over a long enough period with enough breaks in between that we avoid any more serious flooding, but it’s something we’ll continue to monitor this weekend. We’re going to especially watch to see how watersheds like Cypress Creek, Spring Creek, the San Jacinto River, and other slower responding basins handle this. This will also impact the Beaumont and Lake Charles areas to some extent. Which location wins the rainfall derby is still TBD.

What about temperatures, you ask? We should see high temperatures well into the 60s most of next week with lows generally in the 50s to low-60s. This may also lead to periods of sea fog on Galveston Island, Bolivar, and along the bays. Maybe some cooler weather resumes by next weekend.

We will have another update for you by Sunday regarding Monday and next week’s rainfall, and I expect we will be implementing our flood scale then as well.

One of the challenges we face as forecasters during Arctic air events is that often times the models are too slow to push in the cold. This type of cold air is shallow and dense (go ahead and insert your jokes here). If you look at a vertical profile of temperatures from Dallas this morning, you can see just how shallow it is. The red line indicates temperature from the surface (bottom of the chart) to the top of the atmosphere. The temperature scale is tilted (skewed) on these atmospheric soundings (called Skew-T plots). But you can see that in Dallas, it was in the teens this morning at the surface. The line that corresponds to “850” on the left says that temperatures were about 34 or 35 degrees at that height, which is about 5,000 feet up. The line skews warmer about halfway there, so the coldest air is only about 2,500 to 3,000 feet deep.

Since the air mass is so shallow, it’s hard sometimes for modeling, particularly the global models we use 3 to 7 days in advance to pick up on how quickly that dense cold air is going to arrive. So based on our experience, we try to account for this by speeding up the arrival time of cold in our forecasts. Every now and then, however, you get a day like today. Temperatures dropped in Houston to about 37 degrees this morning. Meanwhile, as I write this at 3:45 PM, it’s 50 degrees outside. Weren’t we supposed to be cold today? Yes, we had the front stalling at the coast. Instead, it was as warm as 57 in Galveston, 53 at Hobby, 49 at Bush, but only 40 in Conroe and 29 in College Station.

So, the obvious question most of you have is: Does this mean we aren’t getting as cold? No, it does not mean that at all. In fact, very little has changed, forecast-wise today. Once the sun sets, the cold air will resume its southward push, and by tomorrow morning, you can expect temperatures in the 30s in and around Houston and 20s north.

The problem tomorrow is that temperatures will go nowhere. We will stay in the low 30s with some light showers around, and yes that continues to suggest that light icing will be possible. That could begin as early as overnight north and west of Houston, continuing or expanding south and east during the day tomorrow. So, for the Monday holiday, watch for patchy ice north and west in the morning, across the entire area away from the coast during the afternoon and evening. This will not be a widespread major ice storm by any means, but bridges and overpasses will likely have patchy ice across the area tomorrow and tomorrow night, so please exercise extreme caution on the freeways.

I do not want to speculate much at all on Tuesday morning’s commute and school issues right now. That’s above our pay grade, and I would just sort of plan at this point on Tuesday going normally for most folks but have a backup plan in case it does not.

Forecast temperatures are virtually unchanged tonight, tomorrow, and Tuesday into Tuesday night across the area. So we aren’t looking any worse which is good, and this continues to look like a very cold but very manageable event. And if you want warmer thoughts, look no further than the National Blend of Models forecast over the next 10 days. Yes, another freeze is possible this coming weekend, but by all accounts it looks less significant than this first one. But several days in the 60s appear to be in our future. So take solace if you’re too cold.

We’ll have another update for you in the morning!

One front is through the region, and now we wait for the big dog front later in the weekend. First, we do have some wind to get through today.

Today

With the front to our east now, changes will be afoot today. We barely dropped below 70 (!) overnight, but we just crept into the 60s as I write this, and by the time you read it, it may be in the 50s. It will be a chilly one by mid to late morning. We’ll hold near or just above 50 for the majority of the afternoon. But it will be the wind that’s the real story today. Wind Advisories are posted, and we can expect wind gusts of 30 to 35 mph in Houston, and into the 40s over the bays and along the coast.

Winds will subside toward sunset, with a quieter night ahead. Look for lows tonight in the 30s in much of the area away from the coast. A light freeze will be possible north of the city and in some of the more sheltered areas south, west, or east as well. Temps should not be any colder than we’ve already seen this winter.

Saturday

A fine day. Highs should be around 60 or in the lower-60s. A great day to finish your winterization preparations. And go Texans!

User’s guide to the Arctic cold

With our two posts per day now, we are aiming to update with each main cycle of model data that we are able to see. So there should be fewer big changes with each post. I’m going to change up this post a bit to sort of hit on the key points rather than give a chronological forecast. Here’s what we know.

Key messages

• Front hits Sunday morning ushering in cold (most areas well above freezing)
• Temps in the 30s to near 40 with an east or northeast 10 to 15 mph wind for the Houston Marathon.
• Light precipitation likely Monday and light icing on area roads is possible, especially north and west of Houston. Tuesday AM commute may be impacted in spots.
• Temperatures may stay at or below freezing much of the time Monday morning through Wednesday morning.
• Hard freeze temperatures (less than 25 degrees) would likely last 8 to 10 hours at a time in Houston on Monday night and Tuesday night.
• Wind chills will be as cold as 10 degrees or lower on Tuesday and in the teens much of Tuesday and Wednesday morning.
• We warm well above freezing on Wednesday, with highs near 60 by Thursday.

When does it start?

We need to think of this in two ways: When does it get generically cold and when do we see freezing temperatures? The answer to “when does it get generically cold” is coming into focus. The front looks to hit probably Sunday right around sunrise now. Temperatures in the 40s will probably drop back into the 30s as the front hits, with a light freeze possible north of about The Woodlands on Sunday morning.

The rest of Sunday would be cold but dry with temps in the 30s. A widespread light to moderate freeze is possible Sunday night into Monday morning. A more consequential freeze is possible Monday night into Tuesday morning, with temperatures in the 20s probably everywhere but at the coast, struggling to get above freezing on Tuesday afternoon. And then the coldest on Tuesday night into Wednesday morning. Thankfully, we should bounce back well into the 40s on Wednesday afternoon.

This obviously brings up a couple additional questions.

How bad is the Houston Marathon going to be?

The answer to that question depends on your preference I suppose. I would expect temperatures perhaps dropping as runners are in motion. We may start in the 40s and drop into the 30s or start in the 30s and hold steady throughout. The wind? It doesn’t look horrific, but it doesn’t look great either. We expect northeast to east winds of 10 to 15 mph or so. There will certainly be some gusts near 20 mph at times in there as well. The more meaningful wind should thankfully hold off until Monday or Tuesday.

How cold will it get and for how long?

You can see the chart above for IAH. Let’s answer a few different questions. In Houston, the absolute worst case scenario right now would be temperatures dropping below freezing on Monday morning and staying there through Wednesday morning. Bear in mind that these would be temperatures more in the low-30s Monday (instead of the low to mid-20s like we saw during the February 2021 freeze). A more reasonable scenario is that we poke above freezing for a bit on Monday, then drop back Monday night and stay there into Wednesday morning. The coldest stretches (temperatures of 25 degrees or colder) will probably be limited to 8 to 10 hours at a time Tuesday and Wednesday mornings.

With gusty winds likely on Monday and especially Tuesday, look for wind chill values to drop into the teens much of the time, and at least for a time perhaps in the single digits. This is dangerous cold for pets and people outside, so please make sure to bring in the pets and check on anyone vulnerable to cold exposure.

Will there be wintry precipitation?

A disturbance passing over top of the cold air looks likely on Monday now. This will likely produce 12 to 24 hours of light precipitation across the area. With temperatures hovering near freezing, yes, that means we could see some freezing drizzle or light freezing rain as that precipitation moves through. There’s good news and bad news here. The good news is that amounts look light. So this isn’t going to be an all-out ice storm with lots of power outages due to ice buildup.

The bad news is that any amount of ice can make travel difficult. Monday is a holiday so there will be fewer people on the road already. That’s good news, but if for whatever reason you have to go out on Monday, please check on area roads before you leave. DriveTexas.org is a good resource to have. The Houston TranStar website will show you areas of ice. While there is still uncertainty on exactly how cold it will be Monday, it will be close enough to freezing to think that at least patchy ice will be possible on area roads, especially north and west of Houston and on freeway flyovers.

We don’t want to get into the prediction of traffic or school closures, but yes, you will want to pay attention to how things evolve this weekend for going to back to school or work on Tuesday, as Monday’s conditions could directly impact Tuesday’s commute too.

Will my flight be impacted?

We don’t predict airline behavior here, but yes, probably at some point Bush and Hobby will have some issues, but hopefully nothing major.

When does it end?

As you can see from the temperature forecast above, once we get above freezing on Wednesday morning, we are probably going to stay there into Thursday, with temperatures even near 60 degrees possible! Colder weather should come back next weekend, but it will likely be milder than we will see early next week. We will have more, including a broader look at Texas during this freeze event later today.