Eric Berger

In brief: In today’s post we discuss the state of Houston’s winter to date, which is more or less in line with seasonal predictions. We then look at relatively mild weather for the rest of this week, followed by sharply colder conditions on Sunday and the first half of next week.

Winter update

Don’t look know, but if we define winter as December, January, and February—which is as good a time period for winter in Houston as any—we are now just about halfway through. So far, we have had generally warmer than normal temperatures, with the city’s average temperature in December nearly 6 degrees above normal. Last week was significantly colder, but on average we’re still a few degrees above normal so far this winter.

What is “normal?” Generally, in January, we see highs in the low 60s, and overnight lows in the lower 40s. We will be in the vicinity of that for most of this week, although the mercury goes up toward the end of the work week. We might even hit 70 degrees on Friday or possibly Saturday ahead of a strong front.

If you cast your mind back two months ago, when we published our winter outlook, we predicted a warmer than normal winter. But there was a caveat:

Because of the way this pattern sets up, it will block much of the colder Arctic and Canadian air from the lower United States for most of the winter. But that does not exclude the pattern breaking one or two times. If that happens, and it probably will at least once this winter, there will be a large pool of much colder air available to dip down into the southern United States, including Texas.

We had the first of those outbreaks of colder Arctic air during the first 10 days of January. Now, we’re about to get a second one during the last 10 days of the month. At this point, the upcoming period of colder weather looks like it could be sharper than the first one in early January, with a hard freeze possible for much of the Houston metro area. More on this below.

Tuesday

Winds have shifted to come from the northeast overnight, and they’ll shift further to the east today. This will bring with it an increase in atmospheric moisture and the development of more clouds. This will help to limit high temperatures to the mid- to upper-50s today with milder conditions tonight. Lows will drop into the upper 40s.

Wednesday

This will be a fairly grim day. In addition to mostly cloudy skies, a coastal low will help produce a decent chance of rain showers across the southern half of the metro area, with a lower possibility of rain further inland. Expect highs in the lower 50s, so along with leaden skies and the potential for some light showers this will be dreary affair. Lows on Wednesday night drop into the low- to mid-40s.

Thursday

This day should bring some sunnier skies, with highs of around 60 degrees and overnight lows in the mid-40s.

Friday

This will be a warmer day, with highs near 70 degrees and partly sunny skies. However, there will be chance of showers later in the day, and possibly a few thunderstorms out ahead of a cold front that’s due to push through on Saturday. Lows on Friday night will only drop into the upper 50s, which will be our warmest night for quite a while.

Saturday

The cold front is on schedule to arrive on Saturday, perhaps sometime around the middle of the day. We’ll be reasonably warm ahead of the front, and it looks like colder air will lag a bit behind the frontal passage. So with partly to mostly sunny skies, we could see some highs in the upper 60s. However as evening rolls around the northerly winds will start to really ramp up, ushering in colder and drier air. Look for overnight lows to fall to around 40 degrees in Houston, or a bit lower.

Sunday

If you’re going to be on the start line of the Houston Marathon on Sunday morning like me, you’re going to want to prepare for colder temperatures. The good news is that I don’t expect any precipitation, and skies most likely will be partly to mostly sunny. The bad news is that winds will bring an additional chill into the air. I expect sunrise temperatures to be in the upper 30s in downtown Houston, with the likelihood of wind gusts of 20 to 30 mph. So it will feel really cold, especially in downtown with the tunneling effect between buildings. Even for people who like to run in cold weather, like me, this is pretty chilly. Highs will reach about 50 degrees later on Sunday before temperatures plunge on Sunday night.

Next week

So how cold will things get next week? We just cannot say for certain yet. I think we are probably looking at lows in metro Houston anywhere from the low-20s at the low end, to low-30s at the higher end of the forecast. So that’s the possible range. The coldest days look to be Monday, Tuesday, and Wednesday before temperatures moderate toward the end of the week.

As for precipitation, there’s a non-zero chance of snow or sleet on Monday, Monday night, or Tuesday. I do think snow is at least a possibility, because the atmosphere looks to be freezing all the way down to the ground. But it will depend on whether we get any precipitation, and how much, and at what hours of the day or night. I think the bottom line is that we might expect the possibility of some travel disruptions on Monday or Tuesday of next week, but that does not mean serious issues are likely. We’re just going to have to see how the forecast plays out over the next couple of days. Matt and I will be watching things closely for you.

In brief: Houston will see a warming trend this week, with high temperatures eventually pushing near 70 degrees by Friday or so. We’ll also see plenty of clouds later this week, along with some modest rain chances from Wednesday onward. A strong front arrives on Saturday, and this will usher in a period of significantly colder weather next week.

Early post

Surprise! As I write this it is 5:15 am ET in the Orlando airport, and I am awaiting an early morning flight back to Houston. I’ve been up all night so this post will be fairly brief, but I wanted to dash it off before I pass out. It was an eventful night, with the debut launch of Blue Origin’s New Glenn rocket scrubbed during the final hour of a three-hour launch window. Alas.

Monday

After a chilly start this morning, we should see clearing skies and high temperatures in the mid- to upper-50s. Winds will be brisk, from the north, for much of the day adding an extra bit of chill. Lows tonight will fall to around 40 degrees in Houston. This is likely to be our coldest weather until next Sunday morning.

Tuesday

As winds shift to come from the northeast, we’ll see some more clouds in the sky, and this should limit high temperatures to the mid-50s. Lows on Tuesday night will only drop into the mid-40s as increased cloud cover provides a bit of insulation.

Wednesday and Thursday

As high pressure moves east we’ll see the southern portion of the Houston region become susceptible to a bit of rain. Don’t expect anything serious, but some areas south of Interstate 10 could pick up perhaps half an inch of rain, or a little more, during this period. Chances for inland areas are lower, perhaps just 10 or 20 percent each day. With partly to mostly cloudy skies, expect highs in the mid- to upper-50s. Lows will be milder, in the upper 40s mostly.

Friday

This will be a warmer day, with partly sunny skies and highs of about 70 degrees. Break out the shorts! However there will also be a decent chance of rain (again, mostly light) so this may not be a spectacular day all around. Lows on Friday night will only drop into the upper 50s.

Saturday

This will be another mild day, with highs near 70 degrees and partly sunny skies. At some point on Saturday, perhaps around noon, afternoon, or the evening, a cold front will push into the Houston area. This may bring an additional shot of rain, followed by stronger northerly winds that will really dry us out.

Sunday

The forecast for Sunday, and the Houston Marathon, is continuing to come into better focus. Low temperatures on Sunday morning are likely to be in the upper 30s or lower 40s, but it will feel colder with what is expected to be a fairly stiff northerly breeze. While there’s still the potential for some change, my advice is to prepare to bundle up. Skies should be clearing so I don’t anticipate precipitation being an issue. High temperatures may reach the upper 40s or 50 degrees before another cold night.

Next week

There are no bones about it, next week looks pretty cold. I do think we’re likely to see freezing conditions in the Houston metro area on at least one or two nights, but it remains to be seen whether we see a hard freeze (defined as 28 degrees F or below by the National Weather Service) in Houston. Several people have asked about the potential for snow, or a wintry mix next week. I do think it’s possible on Monday or Tuesday nights, but we just have to see how cold temperatures get, and whether we see any precipitation during these colder times. It’s something we’ll continue to keep an eye on, but it will be a few days at least before we have any definitive answers.

In brief: We’re posting on Sunday to provide a forecast for the Houston Marathon next weekend, as the outlook is coming into better focus. It looks decidedly colder in the wake of a front. Also, we wanted to let you know that Monday’s post will be later than normal.

Programming note

This is a special Sunday update due to the fact that we finally have increasing clarity about the forecast for a week from today, when tens of thousands of people will participate in the Houston Marathon, and more than a quarter of a million people will show up to volunteer and spectate. I’m so appreciative of everyone who is involved.

Also, I want you to know that Monday’s post could be a couple of hours late. Why? Because I’m presently in Florida for the launch of Blue Origin’s New Glenn rocket, and Matt is attending the American Meteorological Society annual meeting. Finally, we are sending a shout-out to the Houston Texans for the dominating playoff win on Saturday. The team showed up when it mattered most.

Weather this week

Houston faces a rather calm week of weather, with chilly but not exceptionally cold weather. Look for highs most days to be in the 50s or lower 60s, with lows around 40 degrees give or take. Skies will be partly sunny with low rain chances after today. Friday and Saturday look warmer, with highs perhaps around 70 degrees.

Previously we’ve written that the outlook for this year’s marathon on January 19 is uncertain due to the timing of a fairly strong cold front this coming weekend. Well, we now have less uncertainty in the timing and strength of this front.

Houston marathon forecast

Since we are still almost a week out from Sunday morning, there is still some wiggle room in the forecast. However over the last 24 hours most of our modeling guidance has come into good agreement. Most likely, a front will push through Houston some time during the day on Saturday, with the potential for some rainfall (nothing too crazy, probably). Then we’ll see colder air follow overnight with gusty winds in place on Sunday morning.

Assuming this timing is correct, and again take nothing for granted this far out, expect temperatures on Sunday morning to be in the upper 30s to lower 40s in downtown Houston. However, it will feel colder if winds are, as expected, out of the north and gusty. The apparent temperature may be down closer to freezing level. Conditions will probably not warm up a whole lot during the morning with additional cold air advection from the north, even if skies are clearing. The good news is that any rain will very likely have exited the area.

The rest of the week following the marathon looks rather cold, although just how very cold we cannot yet say. A freeze is definitely possible. See you tomorrow, albeit later than normal.

In brief: A coastal low pressure system will bring (mostly) moderate rain showers into the Houston area today and tonight. Although we don’t expect any significant flooding, this will be a wet, windy, and dreary day and night. Friday is colder and windy, followed by sunnier conditions this weekend. Sunday looks rather nice with highs of about 60 degrees.

Thursday

After cold, northerly winds since Sunday evening, Houston’s pattern will now change somewhat today as winds shift to become more easterly. This is due to the presence of a coastal low pressure system that will bring increased rain chances today and tonight. Pretty much everyone will see rainfall, but how much, and when?

I think we’ll see an initial pulse of light to moderate showers this morning, with perhaps a slight reprieve during the middle of the day. The best chance of moderate or heavier showers will come later this afternoon, and especially during the evening as a slug of moisture moves up the coast from the southwest to northeast. We should then see the potential for moderate showers through the night, and possibly into the morning hours on Friday. The system should exit to the east between sunrise and noon on Friday.

Most of Houston is likely to pick up 1 to 3 inches of rainfall, and we could see some heavier bullseyes for coastal areas. I do not think these rains will cause any significant flooding issues, and therefore I am not putting a Stage 1 flood alert into place. Additionally, in the Houston metro area none of this will fall as freezing precipitation (the story could be different north of Huntsville or College Station). But do plan to take a little extra time out there because it will be fairly wet later today and tonight.

Temperatures will be in the lower 50s closer to the coast, and in the 40s further inland. The cold weather will be compounded by a strong easterly wind which may, at times, gust as high as 30 mph. So all in all, not a fun day or evening to be outside.

Friday

After the coastal low departs, we’ll see increasing northwesterly winds, and this will usher in another push of colder and drier air. So Friday will be a cold day, with highs in the lower 40s, and breezy conditions adding some wind chill on top. As skies clear out we’ll see ideal conditions for cold weather on Friday night, and much of the Houston area should see one more freeze. It will be light in Houston, but some areas in Montgomery County and to the northwest of Houston may see a hard freeze.

Saturday and Sunday

After the chilly start, the rest of the weekend looks sunny and warmer. Highs on Saturday should reach about 50 degrees, with nighttime temperatures a few degrees above freezing in the metro area. Sunday will be mostly sunny and warmer, with highs of around 60 degrees. Time to get back in the pool?

Next week

Most of next week looks to be slightly warmer, with highs in the 50s to lower 60s, and low temperatures in the vicinity of 40 degrees. This is fairly typical weather for mid-January. We’ll see a mixture of clouds and sunshine. As we head toward next weekend highs may climb toward about 70 degrees. There’s still a fair bit of uncertainty about weather for the Houston Marathon on Sunday January 19, as it looks like a front will be trying to come through next weekend. Temperatures, and any rainfall, will depend on the timing and strength of that front. Right now I’d ballpark start line temperatures at about 50 degrees, but there remains a wide variance in possibilities.