Eric Berger

In brief: In this Christmas Eve update we discuss all of the fog recorded by Houston recently. Why has there been so much? When is it going away? Will Rudolph find his way tonight? Also, next week’s cooldown looks fairly stout, sending nighttime temperatures into the 30s.

All about fog, because it’s not going away

Ugh. That’s the typical reaction you’ll get from a meteorologist when it comes to fog. It’s no fun to forecast, and it’s no fun to drive through. About the only thing fog is good for, in my opinion, is establishing a really atmospheric scene in the movies, like the opening battle in the original Gladiator. But aside from that? Ugh. If you’ve got reasons to love fog, I’d like to hear them.

Anyway, the main engine of fog in the greater Houston region during the late fall, winter, and early spring months is the Gulf. By this time of year we have had enough cool fronts come down that the near-shore waters of the Gulf, and Galveston Bay, have generally cooled down to 60 to 65 degrees. (You can check the data for yourself, here).

The important thing is that at night, and in the morning hours, air temperatures remain a little bit warmer than water temperatures, even without the Sun shining. So when we’re in a steamy pattern like we’ve been in, you’ve got this warm and humid air moving over the colder water. This cools the air to the point of saturation, which means the air is saturated with water vapor. This occurs when the air temperature equals the dewpoint temperature. So presto, we’ve got a big fog machine that gets turned on every night. This is known as marine fog.

Houston is susceptible to another kind of fog over inland areas, that forms at night when the air temperature starts to cool. Because the air is already fairly humid, the temperature does not have to drop that far to reach saturation. This process generally needs light winds, so that the lower and more humid air at the surface does not mix with slightly drier air above. This is known as “radiation fog,” and it goes away as the air temperature rises along with the Sun in the morning. This is the origin of phrases like the Sun is “burning off” the fog. In reality, the air temperature is rising above the dewpoint temperature, causing the fog to evaporate.

This foggy pattern is going to be with us until we get a wind shift (from the north rather than southeast), which is likely to happen on Sunday.

Christmas Eve and Christmas Day

The next two days are going to be more or less the same as we’ve experienced so far this week. They’re going to start out with patchy fog, followed by temperatures rising into the upper 70s to lower 80s, and partly cloudy skies. Nights will be warm, generally in the mid-60s. Rain chances are low to non-existent. If you’re wondering how my long-range Christmas forecast (issued 12 days ago!) did, here you go:

I’m sorry I was not wrong.

Friday and Saturday

The end of the week should continue to see warm and fairly humid weather. If anything, we should see a little more sunshine, and this will push air temperatures to 80 degrees, or the low 80s, for many records. We have already tied several high records this week, and we are apparently gunning for more. Nights remain with, with a chance of patchy fog.

Sunday and beyond

Sunday should be fairly warm as well, with highs pushing into the upper 70s, to possibly 80 degrees. A strong front is coming, but it’s now unlikely to reach our region before Sunday evening or the overnight hours. After this we’ll have a few cold days next week, with highs likely in the 50s, and lows in the 30s and 40s. I don’t think the majority of the metro area will see a freeze on Tuesday morning, but it’s a possibility we’ll be watching for as the mercury bottoms out. Temperatures should rebound a little by New Year’s Eve into the 60s, but at this point I suspect temperatures that night, heading into New Year’s Day will be chilly and in the 40s. So it will be fairly cold if you’re planning to be outside for revelries. The end of next week looks a little warmer.

From all of us at Space City Weather, we would like to wish you a very Merry Christmas and Happy Holidays. See you on Friday morning.

In brief: We have a shorter post today, because there are only so many ways one can slice and dice our repetitive weather this week. A strong front arrives Sunday or Sunday night to return us to winterlike conditions.

Holiday plans

Given the Christmas Day holiday, our plan is to take Thursday off this week. (And really, our forecast is not going to change much between now and then). Some of our daily posts during the holiday week will also be a little shorter because really, there is just not that much to say. However that does not mean we will be bereft of gifts. To mark the Festivus holiday, we are publishing a special Q&A this morning at 10 am CT. So be sure and check back for feats of strength and airing of grievances from readers.

Tuesday through Saturday

Yes, we can confidently forecast the weather for the next six days beneath a single heading. The days really will be that repetitive due to a persistent ridge of high pressure. Each day will start out with a healthy chance of fog, especially closer to the coast. We will then see partly sunny skies. The only difference this week is that the next couple of days may see a few more clouds, and Friday and Saturday a little more sunshine. Either way we will see high temperatures in the vicinity of 80 degrees, with plenty of humidity. Lows will drop into the mid-60s in Houston, with slightly warmer conditions near the coast, and slightly cooler inland. Morning winds will be light, with some moderate gusts building during the afternoon. And that’s it, rinse and repeat through Saturday.

Sunday

Change finally arrives on Sunday or Sunday night. Accordingly I think Sunday will start out as another warm day before a shot of colder and drier air arrives. Our lows on Sunday night will depend on how much time there is for the cooler air to push in, but 50 degrees seems about right. Rain chances with the front, and yes I know we could use some, are pretty low—something on the order of 20 percent perhaps.

Next week

Monday Tuesday and Wednesday look chilly, with daytime highs perhaps in the 50s or 60s, and lows in the 30s or 40s. We may see a bit of a warming trend by New Year’s Eve and New Year’s Day, but I’m not particularly confident in that. I’ll take a closer look at conditions surrounding New Year’s in tomorrow’s post.

In brief: In this morning’s post we provide an update on our toasty weather for this week. However, if the unseasonable heat has you hot and bothered, we now have a pretty firm expiration date for our warm conditions.

Unseasonable seasons greetings

Well, here we are, a mere three days before Christmas Day. And instead of “ho, ho, ho” any visiting Santa Clauses are more likely to say, “hot, hot, hot!” And who could blame them? High temperatures this week will likely reach 80 degrees every day through Saturday, or get very close to it, with nights in the mid-60s.

In terms of what is normal for this time of year, we are generally running about 15 degrees above where the December mercury usually resides. As we have been saying for awhile now, a potent high pressure system has set up over the central United States, and nearly the entire Lower 48 is going to see abnormally high temperatures during Christmas week.

Along with the daytime warmth we are going to experience dewpoints in the upper 60s to start the week, which is really, really sticky for this time of year. These should drop slightly throughout the week, but for real relief we are going to have to wait until Sunday, at least. Because of generally light winds and warm nights, we also are going to have a healthy chance of fog each morning, through Saturday. This is, unfortunately, an extremely high confidence forecast.

Monday through Friday

There’s no real sense in breaking out day-to-day forecasts, because not much is going to change in our sensible weather this week. Each day will bring highs in the upper 70s to 80 degrees. Daily record highs for this time of year range from 81 to 84 degrees, so we’ll be keeping a close eye on those. Nighttime lows will generally fall into the mid-60s in Houston, with conditions a little cooler inland, and a little warmer along the coast. Days will be partly to mostly sunny, with more clouds at night. Dense fog will be possible each morning. Winds will be calm during the morning hours, with a southerly breeze during the afternoon.

Saturday

At this point Saturday probably will be more or less a continuation of this week’s weather. A potent front is coming this weekend, but at this point I think it will hold off until Sunday. If the front accelerates we might see some showers later on Saturday, but right now I’m doubtful.

Sunday

Some relief should finally arrive on Sunday, although the time is to be determined. We may see some light showers with the front’s passage, but overall chances look to be fairly low. Temperatures on Sunday will depend on the timing of the front, but for now let’s go with highs in the 70s.

Next week

Temperatures should drop back for several days next week. It’s too early to have much precision, but beginning Monday we should see a few days with highs in the 60s and lows in the 40s, although it’s possible we could get colder than that for a night or two. As for New Year’s Eve, we probably will be on a slight warming trend, but my confidence is starting to wane in the forecast by then.

In brief: It is chilly across Houston this morning, with some outlying areas falling all the way into the upper 30s. Most of us are in the lower 40s. This is as cold we are going to get for awhile, and in fact a rather swift warm-up will begin 24 hours from now. We’ll then be unseasonably warm through the Christmas holiday.

A brief reminder that it’s winter

It is fairly chilly out there this morning. Some locations in Montgomery County, including the usual spots like Conroe, have fallen into the 30s and may be experiencing some frost. Most of the rest of the Houston metro area is in the 40s. Our weather is clear, and cool, and just about normal for this time of year when our days are the shortest.

If you like winter (and I know many of you do not), make sure to spend a little time outside today. Because when you look at a forecast for the days ahead it is kind of wild. We are briefly cold, and then it’s at least a solid week of rather balmy weather, with highs near record maximum temperatures. I’d love to tell you it won’t be humid, but with dewpoints solidly in the mid-60s, it will be. And we are going to be prone to early morning fog, which I don’t think anyone likes. (If you do, explain yourself in the comments!)

On the upside, beyond the fog, there is very little to be concerned about. We aren’t going to have snow or icy roads, and there is no signal for any kind of severe weather. So while it won’t feel exactly festive out there, family gatherings should not be impacted by the weather. As a forecaster, selfishly, it also makes our job a bit easier during the holiday week when there are lots of activities with families and friends!

Friday

Today is really going to be a lovely winter day. Overnight winds have calmed down, and we’re going to have a sunny day with highs in the mid-60s. There is literally going to be nothing to complain about, although I know some readers will take that as a challenge. We are going to have one more passably chilly night, with lows in the upper 40s for most of the region. But with the onshore flow resuming on Friday night, we are going to warm up quickly on Saturday morning.

Saturday through Tuesday

After Saturday morning we’re going to see steady-eddie weather, with highs in the upper 70s to 80 degrees, a mix of sunshine and clouds, warm nights in the mid-60s, and a chance of morning fog. Rain chances will be close to zero each day. Really, I don’t expect much change from day to day, which is how it goes with potent high pressure systems like this.

Christmas Eve, Christmas Day, and Boxing Day

For those who don’t know, Boxing Day is December 26th, and celebrated in Canada and elsewhere in the Commonwealth nations. No one is quite sure why it’s called “Boxing” day, but it has nothing to do with fighting. And I thought I would call it out this year because there is a Canadian astronaut, Jeremy Hansen, flying on the Artemis II mission around the Moon early next year. He and his family have spent a lot of time in Houston, while he trains at NASA, and Jeremy is a swell fellow.

Anyway, I don’t expect much change in daytime temperatures during the second half of next week, but we could see a slight diminution in humidity, and this would allow for nighttime temperatures to drop by a couple of degrees. My prediction for Christmas Day remains the same as it’s been for more than a week now: Highs in the upper 70s, a decent amount of humidity, and partly sunny skies. Rain chances are very low. You can trade ugly sweaters for ugly sweating, if you like.

Is it ever going to feel like winter again?

Yes. Most of our trusted models show a significant pattern change around Sunday, Dec. 28, or Monday, Jan. 29. Since that is at the edge of predictability, we should take it with a grain of salt. But I remain hopeful that winter will eventually start to feel like winter again.

Since the forecast is pretty well locked in we’re going to take a full weekend off here. See you on Monday!