Matt Lanza

In brief: A major winter storm continues to look likely for the Houston area Monday night and Tuesday, with the potential for heavy snow and sleet in parts of the region. Minor ice may occur near the coast, along with windy conditions. Travel will become difficult to impossible Tuesday morning and remain that way through at least Wednesday morning across most of the area. A significant, damaging freeze is likely Wednesday morning as well. We do warm up Thursday.

Current cold

If you’ve stepped outside, or like Eric, started running the Chevron Houston Marathon, you know it’s, um, cold.

Speaking of which, let’s check on Eric as of 8:40 am! Good luck to Eric the rest of the way!

Temperatures will recover some today, getting up into the low or mid-40s. Another cold night is expected tonight, with lows in the 20s across most of the area away from the coast. Expect a hard freeze for many outlying areas and some areas in the city too.

Remember the basic preparations you should be taking.

• PLANTS. Protect tropical vegetation. Please note, with temperatures dropping this low, some vegetation will probably die regardless.
• PIPES. Protect any exposed outdoor pipes. Pipes in attics and along exterior walls of structures could freeze at these levels.
• SPRINKLERS. Sprinkler systems should be shut off and properly drained.
• ANIMALS. Prepare proper shelter and warmth for animals and livestock and make sure water sources are not frozen.

And also remember to check on people that may not have adequate insulation or access to heating.

Monday

Most of tomorrow should be fine. We will see increasing clouds that may hold temperatures back a bit. Highs should be in the upper-30s. Precipitation begins sometime either Monday afternoon or evening. With temperatures comfortably above freezing, whatever falls initially may be a light rain. Resist the urge to call bust.

Sidebar: The air mass over us will be quite dry. This is important. As the rain begins falling on Monday afternoon and evening, it may fall as virga (rain that does not reach the ground). But as it evaporates on the way down, it will cool the entirety of the atmosphere from a few thousand feet up to the ground. This is essentially priming us for snow and sleet. So initially, it may fall as rain, but that will change Monday night.

The best advice we initially can offer: Be where you need to be by early Monday evening and prepare to be stuck there through at least Wednesday morning.

Monday night and Tuesday morning winter storm

As the precip increases in coverage and intensity and temperatures drop, we will see a changeover from rain to a mix of sleet and snow. I have to be honest: Much of the model data seems to be favoring a gradual change from sleet to mostly snow, especially along and north of I-10. South of there, it should still be a mix of sleet and snow, with potentially a little freezing rain near the coast or Matagorda Bay area.

A couple notes about how things will unfold.

• This storm has been strongly signaling what we call mesoscale banding or the potential for a deformation zone. In plain language? There will be widespread snow and sleet, but embedded within that will be a couple corridors of heavy snow. Those bands can see quick, heavy accumulation and snow rates of 1 to 2 inches per hour, along with the potential for thundersnow.
• That banding will also lead to a disparity in snow totals. You could, in theory, have an area that sees 2 to 3 inches and literally down the road an area that gets 6 or 7 inches.
• Sleet is the biggest risk to all this. If we end up with significant sleet and less snow, accumulations will be much lower — but travel will be just as bad. Models are trending toward more snow over sleet for much of the region, but admittedly, this is not an area where models handle things super wonderfully.
• Wind will howl on Tuesday morning, especially on Galveston Island, where gusts could exceed 40 to 45 mph. Inland gusts will be to 20 to 30 mph. Coupled with areas of heavy snow, this will create extremely poor visibility and potentially some blowing and drifting of snow. Yes, that’s an actual sentence I just typed for Southeast Texas.

When all is said and done, how much snow will you get in your backyard? The official NWS forecast is shown below.

I will say that the risk is probably asymmetrically skewed to the higher side here. In other words, there is a chance of more snow than shown, but again it will depend on sleet and exactly where those “mesoscale bands” setup. Max totals could be, could be as high as 6 to 8 inches. But those will likely be the exception, not the rule.

How about ice? Well, the official NWS forecast is one that isn’t overly bullish on ice, which is good news. Ice is where you can start to have more meaningful issues with infrastructure issues (trees, power lines, etc.). Ice of this amount would make conditions a little extra slippery but be unlikely to cause damage.

The highest ice totals are likely to be south of I-10 and in the Victoria Crossroads back toward south of San Antonio.

Travel concerns

There’s no real good way to get around this: We are inherently unprepared for a major snowstorm because, well, it rarely ever happens. Thus, you can expect that travel will be difficult to perhaps impossible on Tuesday, probably Wednesday morning, and maybe even Wednesday afternoon. We really cannot underscore this enough: Barring a dramatic forecast change, tou will probably not be able to get very far in a vehicle Tuesday or Wednesday morning. Your flight will probably be cancelled. Prepare to be stuck where you are after Monday evening.

Wednesday morning hard freeze

With ideal conditions for cold weather, including fresh snow on the ground, you can expect Wednesday morning to be very, very cold. While it won’t be super cold across the rest of Texas, locally here in Southeast Texas, we may rival one of our coldest mornings of the last few years.

Expect lows in the teens virtually everywhere away from the coast. Areas that see minimal snow accumulation will also likely be milder. This will be a hard, damaging freeze and maximum cold weather precautions need to be taken.

Wednesday afternoon should see sunshine but with snow and a bitter cold start, we will likely only get into the mid-30s or so. Another hard freeze is possible Wednesday night, albeit much less cold than Wednesday morning. And we should bounce back into the 40s on Thursday. Alas, the snow will melt.

Anyway, we’ll update you on any changes later this afternoon. But hopefully this post answers most of your questions in the meantime. Stay warm!

In brief: A complicated winter storm for Houston next week continues to give us fits in weather modeling, with today’s flavor being the potential for more snow and sleet than anything else. However, we expect the forecast to continue changing over the weekend and will keep you posted. Either way, travel across the Houston area may become very difficult Tuesday and Wednesday.

Winter storm update

What has changed since yesterday? Well, a lot. The storm is back. But this time it’s a bit colder overall, which means perhaps more in the way of snow and sleet than ice. That would be good news. That said, there remains a ton of uncertainty. As a native of New Jersey and having cut my teeth forecasting in Upstate New York, I have learned to never take a winter weather forecast from models literally. This is doubly true in the South where snow and ice are generally outside the bounds of climatology, which tends to give models fits and leads to us having to caveat every single thing we say.

Anyway, here’s the NWS National Blend of Models snow forecast for the last several runs. This incorporates a bunch of models and weights them. You can see a lot of fluctuation in outcomes here.

What are we confident in? The timing. Precipitation should begin, lightly on Monday afternoon or evening. The height of the storm would likely be from about 4 AM to Noon Tuesday, with conditions slowly improving Tuesday afternoon. We are also fairly confident that Wednesday morning should be the coldest morning next week. A tropical-plant damaging freeze is likely on at least one or two mornings. An irrigation system damaging freeze is also likely if precautions are not taken.

What are we not confident in? How much of what falls where. While the models have brought the storm back into the forecast since yesterday, they remain a bit split on exactly how it plays out. We can say that in general today, it appears the highest odds of snow are north and east of Houston and the highest odds of ice are south of Houston and near the coast. Beyond that? We can’t say much. Unfortunately, that’s the most important question to answer in terms of travel conditions, school closures, etc. We will get some confidence on this through the weekend. We would think that by the morning of the MLK holiday, decisionmakers will have enough to work with.

What else aren’t we confident in? How cold it gets Wednesday morning. Snow cover is a significant component of what we refer to in meteorology as “ideal radiational cooling,” the premise being clear skies, light winds, and snow cover all contribute toward an ideal scenario for cold weather. Without snow cover next week, we’ll likely see mostly 20s for lows with a few teens north. Cold for sure, but nothing extreme. However, let’s say we get 2″ of snow across Houston. Then we could easily shave an additional 5 degrees off that, nudging us into the teens everywhere except the coast.

So there is a lot to unpack here still, and over the next couple days we should begin to see clarity. Eric and I will keep you posted on all that as it evolves with regular updates through the weekend.

Houston Marathon

I admire anyone that runs a marathon. I especially admire anyone that does so with temperatures in the 30s and a north wind gusting up to 25 mph or so. That’s what we have for you on Sunday. Temps will rise a little through the run, possibly getting to near 40 degrees by the end, but either way, it’s going to be very cold. Good luck to Eric and to all those participating in the run(s) this year!

Rest of the forecast

For those of you with weekend plans, there could be an isolated shower this afternoon or tomorrow afternoon as the front moves in, but otherwise it looks dry. Temperatures will peak in the upper-60s or low-70s today, so bust out the shorts and enjoy! Tomorrow will likely get into the 60s before the front hits in the afternoon. Temperatures will then fall tomorrow evening through the 50s and 40s and into the 30s in most of the area, with some 20s in more rural spots north of I-10 by Sunday morning. Sunday gets up to the low or mid-40s, maybe and looks windy and cold.

Monday will start in the 20s and warm into the upper-30s to low-40s. Depending on how the storm evolves, look for lows in the upper-20s and highs in the low or mid-30s on Tuesday with a breeze as well. Wednesday will probably get up near 40, but as noted above, there is some uncertainty on how cold it gets in the morning. And then a more proper warm up ensues for later next week.

Again, we will keep you posted regularly through the weekend on next week’s cold and potential winter precipitation.

In brief: After a solid 1 to 4 inch rainstorm in the Houston and Galveston areas last night, we aim for calmer conditions today. Saturday should be a lovely winter’s day, followed by a chance of rain on Sunday. Next week looks quiet with a slow warm-up after a chilly start.

One quick housekeeping item: If you missed it yesterday, those of you who use our app on Apple devices should now have a solution to issues that prevented you from receiving notifications when we post. Check that out here from Dwight.

Weather-wise, it sure rained last night. Often when we look at rainfall estimate maps, they’re fairly erratic. The one for the last 24 hours is not. Everyone saw about 1 to 2 inches, with isolated higher amounts south and east and down close to Victoria. Galveston saw nearly 4 inches of rain and peak wind gusts of 50 to 55 mph.

But this was just a good old fashioned coastal storm that delivered basically as promised. Now, we get some quieter weather.

Today

It will remain dreary and cold today. Look for clouds to stick around most of the day, though there could be a few breaks of sunshine. Temperatures should only warm into the mid-40s today, though if we see more clearing than forecast, we’ll make a run at 50 degrees. Winds will back down a bit, though it’ll still feel like the 30s through the day.

Tonight

Clear skies and calm winds tonight will allow for a pretty cold evening. Look for another generally light freeze with temperatures in the low-30s in the city and upper 20s in the suburbs. We could see some mid-20s in far north and northwest areas (Conroe to College Station).

Some patchy fog could develop Saturday morning as well up north. With temperatures below freezing, this could lead to a few icy patches on roads to the north of the Houston area. We aren’t expecting anything widespread, but this is something to just be aware of up north, mostly well away from the Houston Metro and suburbs.

Rest of the weekend

Saturday looks like a lovely winter’s day after any fog dissipates: Sunshine with highs in the 50s. It will be milder Saturday night with lows in the 30s and 40s as clouds move back in. Sunday is trending a bit wetter now with showers developing, especially south and east of Houston. I’m not ready to call it a washout, but it’s looking damp with perhaps up to a half-inch of rain at the coast and a quarter-inch inland. Highs will be in the mid to upper-50s.

Next week

We get a dose of somewhat cooler weather early in the week behind Sunday’s system, but it should only produce highs in the 50s and lows in the 30s. Just some more winter. A warming trend ensues later next week which should push high temps back into the 60s again. We are not expecting anything other than clouds and sun for most of the week right now. More cold weather may follow after next weekend, but it’s a bit soon to say just how cold that will be.

In brief: The chances of severe weather today in Houston have increased a bit, although it still appears locations to north and east of the city will be at highest risk overall. Still, there will likely be showers and noisy thunderstorms around. A couple storms, primarily north of I-10 will be capable of producing hail, damaging wind, or an isolated tornado.

We’re on the every-other-day plan here in Houston right now. Storms on Tuesday, a mini-tornado outbreak on Thursday, and now the area will have another chance at thunderstorms and severe weather today. The forecast has indeed gotten a little more challenging here today, which I explain a bit more about below.

The Houston area is under a slight risk (level 2/5) and marginal risk (level 1/5) for severe weather today.

A couple things have happened today to cause these subtle but meaningful changes. We saw minimal showers and storms this morning. Now that the atmosphere is destabilizing a bit, we’ll see more development occur. And, as I speculate on “why” below, modeling generally just didn’t get it quite right based on what they show today. Never verify a forecast on a forecast though, so we’ll see what eventually happens here.

Anyway, a few showers are now beginning to pop up across the area, especially west of Katy and northeast of Baytown. Additionally, a line of thunderstorms is developing back west along I-35 that will become a focal point for general storms and isolated severe weather today.

Over the next 3 hours, expect showers to increase in coverage on the west and north sides of the Houston metro. Some of these showers and storms will also increase in intensity with severe risks going up, especially north of I-10 after about 11 AM or Noon.

Early to mid-afternoon should see peak coverage and intensity. If the area sees another tornado, it would probably happen in that timeframe, though the odds favor something like that happening north and east of Lake Livingston. But as we saw on Thursday, when odds of severe weather were also highest north and east, the most “photogenic” tornado actually occurred back in El Campo. So, while we are confident that the highest odds of bad weather are to the north and east, our odds here are certainly not zero. Have a way to receive weather alerts today if you’ll be out and about, just so you’re aware of anything changing.

Storms should begin to “line out” and exit the area west to east after 4 PM or so, with quiet weather expected tonight. Tomorrow still looks delightful, with sunshine and comfortable temperatures around 70 degrees.

Playing catch-up?

Worth noting: One commenter pointed out yesterday that it seems like each event has been generally forecast to happen but has tended to worsen as it got closer to happening. Today obviously fits that trend once more. As for why that is? I can’t really pinpoint it with certainty right now. However, I might speculate that an extremely warm western Gulf of Mexico might have something to do with this.

Warm water can help inject more moisture and instability into the atmosphere, and especially so when you’re dealing with temperatures that are as much as 3.5°C warmer than normal. Why would that impact the forecast; shouldn’t this be baked in? The answer is not necessarily. Sometimes models have trouble catching up to anomalies this significant. So it would not be shocking for there to be an element of underforecasting severe risk in this environment by some extent. But I am speculating a bit here. Whatever the case, the pattern mercifully changes after today, and we will see limited to no rain chances until late next week or weekend.