In brief: In today’s post we discuss the return of fog, and some humidity. A sharp front arrives Sunday that will bring a chance of a light freeze into Houston. After that we’re going to warm up. Will some cooler air arrive in time for Christmas? Find out in our way-too-early Christmas Day forecast.

Christmas Day forecast

Don’t worry, Christmas shoppers. You still have 13 days before the holiday. Which means it is ridiculously early to try and forecast the weather (realistically, about 10 days is the limit). Nevertheless, readers have been asking, and we aim to deliver. Just understand that you’ve been warned, and there may more coal stocked in this forecast than candy.

As we’ve been saying for a couple of days now, the run-up to Christmas Day looks rather warm. Record highs in Houston are generally in the 81 to 83 range for the last 10 days of December, and beginning next weekend (Dec. 20 or Dec. 21) we are likely going to be flirting with this range of temperatures. We are reasonably confident in this forecast because high pressure patterns are fairly straightforward to predict.

At some point the pattern will break, and we will see a more winter-like pattern emerge. In late December it is more difficult for these highs to persist in this manner. However, we just can’t say whether a front will come on Christmas Eve, Christmas Day, or even later in the holiday week. For that reason I’m going to go with a forecast high of 80 degrees on Christmas, with fairly humid conditions and mostly cloudy skies. I would dearly love to be wrong about that, mind you.

Friday

Temperatures and dewpoints are basically the same this morning, in the low- to mid-50s, with calm winds. That’s a great recipe for dense fog, which is just what we’ve got. It should gradually diminish after sunrise, but it will be nuisance until then. We can expect more of this on Saturday and possibly Sunday mornings. Highs today will climb into the mid- to upper-70s today, with partly to mostly cloudy skies. With dewpoints rising into the 60s, it will feel modestly humid as well. Low temperatures tonight will only drop into the 60s.

Saturday

The first half of the weekend will be similarly warm and humid, with highs in the upper 70s. Skies will also be partly cloudy, although some clearing is possible during the afternoon hours. There is also a chance of some light showers during the daytime, perhaps 20 or 30 percent, so keep that in mind if you have outdoor plans. Saturday night also looks fairly warm and muggy.

Sunday

Temperatures will start out in the low- to mid-60s on Sunday morning, and that is where they will peak ahead of a fairly strong cold front. It will likely arrive around sunrise in Houston, a little before north of Interstate 10, and a little later closer to the coast. We could see some light showers with the front, although I’m not expecting anything at all serious in the way of accumulations. We’ll see clearing skies during the afternoon, along with winds gusting to perhaps 25 mph. These gusts should back off a bit during the evening hours.

Temperatures will drop throughout the day, accelerating during the late afternoon and evening hours. I expect lows for most of the city, except for the immediate coast, to reach the 30s by Monday morning. As for a freeze, it’s a good question. If you live in Montgomery or Chambers County, I think there’s probably at least a 50 percent chance of a freeze on Sunday night, whereas in the city of Houston and points south and west of Houston, the odds are quite a bit lower. We’ll do a short post this weekend updating you on the expected freeze line.

Next week

Monday will be cold, in the 50s, and mostly clear. We should see another chilly night, albeit in the low 40s, as the onshore flow resumes. By Wednesday our daytime temperatures will be solidly in the 70s. There is a slight hint in some of the models of a front in the Friday time frame of next week, but it’s not something I would count on. After that we’re into the warm run-up to Christmas I spoke about above.

Have a wonderful weekend, everyone!

In brief: A lovely day today in Houston will give way to a warm up tomorrow and fog and shower chances on Saturday. Our next front Sunday morning may knock temps back close to freezing in spots on Monday morning before we begin what could be a prolonged, serious warm up leading into Christmas.

Today

It’s a crisp start to Thursday with temperatures in the 40s and some pockets of 30s in northern fringes of the region. It will be a lovely day today with highs in the 60s to perhaps near 70 in spots south and west of Houston. Lots of sunshine.

Friday and Saturday

Tomorrow looks like our transition back into warmer temperatures. With clouds and sun, we should manage to warm from the 40s and 50s in the morning to the 60s and 70s in the afternoon. Some areas near Downtown or just southeast of there will push the mid to upper-70s.

Friday night will be milder with lows the 50s to low-60s mostly. Saturday does feature a return of shower chances, though if you have outdoor plans I’m not quite sure it’s anything you need to plan around just yet. The day will start gloomy with areas of perhaps dense fog and some drizzle. Gradually, skies should brighten, and with that will come the shower or isolated thunderstorm chance.

Sunday

On Saturday night, a cold front will push through with another chance at showers or a thunderstorm. The front is currently timed to hit around sunrise on Sunday. Temperatures may actually drop through the morning on Sunday back into the 50s across the area for most of the afternoon. Our high temperature on Sunday may be around or just after Midnight. It will turn blustery too with 10 to 20 mph winds across the area, higher on the coast.

Could parts of the area freeze Monday morning?

As Eric noted yesterday, temperatures falling into the 30s was possible on Sunday night. Recent model trends have gotten more aggressive with bringing colder air into the area. To be clear, this won’t be a hard or particularly dangerous freeze. However, inland, rural, sheltered locations could nudge back close to 30 degrees. In Houston proper, I doubt we get much below 34 degrees right now, but it will be quite chilly on Monday morning.

Stay tuned!

Next week

Monday itself will be cold with highs only in the 50s. Tuesday should warm into the 60s with milder morning lows (40s mostly). By Wednesday we are in the 70s. Beyond Wednesday, the question will become how warm it gets. As Eric alluded to on Wednesday, the run up to Christmas looks quite warm. In fact, over 50 percent of model ensemble members are calling for a high temperature above 80 degrees by next weekend. It appears that it will not feel like Christmas this year in the days leading up to the holiday. More to come.

In brief: In today’s post we discuss a warmup in our weather through Saturday, followed by a short but sharp cold front on Sunday. We also spend some time talking about how the week before Christmas is likely to bring warmer-than-normal weather.

A very early look at the weather preceding Christmas

I’m not ready to break out into “Mele Kalikimaka” yet—the Hawaiian-themed Christmas song popularized by Bing Crosby, and appearing in Christmas Vacation, among other movies—but the middle of December is starting to look somewhat warm. To be clear, we’re not there yet. We have some chilly mornings today and Thursday, and a cold front arriving on Sunday could pack a fairly sharp punch. Parts of Houston are likely to flirt with a freeze early next week.

But this morning I want to talk about what comes after this, during the week preceding Christmas beginning around December 18. That is within the edge of what is possible to forecast, and the data were seeing point to above average temperatures across Texas. It appears that high pressure will build over the western United States in a fairly stable pattern. I don’t think we’re looking at anything too crazy, but for the most part we can probably expect highs in the 70s, with lows in the 50s and 60s. A front or two could still sneak in, but overall we should be warmer than average. As for what happens by Christmas Day, it remains a little far out to say anything with confidence. Which means, of course, I’ll make a stupidly early Christmas forecast in the next day or two.

Wednesday

Temperatures this morning are generally in the mid- to upper-40s across Houston, with clear skies (it’s a beautiful sunrise, I must say). We are going to warm nicely this afternoon, into the low 70s for the most part. We would be well on our way to a significant warming trend, but for the fact that a reinforcing front will arrive today, with light winds shifting to come from the north this afternoon. This cooler air will allow temperatures to drop into the 40s tonight, with a few outlying areas possibly returning to the upper 30s. I don’t expect any rain, or possibly even any clouds, to accompany the front.

Thursday

This will be a sunny day, with highs in the 60s. As winds shift to come from the south we are going to see a warmer night, in the 50s.

Friday and Saturday

This period will be warmer, with a southerly flow off the Gulf. Look for daytime highs in the mid- to upper-70s, and nights with lows around 60 degrees. Skies will be partly sunny, with only very slight rain chances.

Sunday

Sunday is likely to start out moderately warm as well, but our confidence is now fairly high in a cold front dropping down from the north during the daytime. This will bring with it a decent shot of rain, but overall accumulations for most should be on the lower side, almost certainly less than half an inch (and probably less than this). In the wake of the front I expect a cold night. Temperatures probably will drop into the 40s in Houston, but there is a chance of falling all the way into the 30s. I’m not entirely ruling out a freeze for some inland locations, as we’ll just have to see how much cold Arctic air makes it into Texas, rather than being shunted off to the east before dropping this far south.

Next week

Monday and Tuesday of next week looks rather chilly before—as I wrote at the outset of this post—we see a warming trend that could stick around awhile.

In brief: In today’s post we discuss this morning’s chilly start, and our warming trend through Saturday. We also provide some clarity on the weekend forecast. And finally, our Dwight Silverman explains what the heck happened to the cities in the Space City Weather App.

Encyclopedia Brown and the Case of the Missing Cities

We love a mystery, except when it involves weird problems with the Space City Weather app. We do, however, love a mystery when it’s solved.

Users of the app noticed that, over the past couple of weeks, the list of cities available to choose in the left-hand tray would be decimated to just a few, but by the end of the day the full list would be restored.

Initially, we thought this had to do with a new version of the National Weather Service’s Application Programming Interface, or API, which is how we get the data that populates the current conditions and forecasts on the app’s home page.

Then we found the problem, and it was ours, not the NWS’, fault (sorry, y’all!).

It turns out the strange case of the vanishing cities was caused by a bug in the app that was triggered when the temperature values coming from NWS drop below a certain point—something we couldn’t easily test for when it the new version of the app was under development because the weather was warm (which it seems to be in Houston until at least November).

The app calculates Heat Index and Wind Chill differently (they show up in the same box in the conditions portion of the home screen). When temperatures dropped and the app switched over from the Heat Index to Wind Chill, it generated a value that the app didn’t understand. It then quit showing the cities where it was cold.

But as the day warmed up and the current temps rose to the Heat Index threshold, the correct values were generated and the cities reappeared. Which is why, during the day, we’d have more and more cities return to the picker.

Our developer Hussain Abbasi has fixed the bug and a new version is now available in the Android and Apple app stores.

Thanks to everyone who sent reports via the Feedback selection in the app’s Settings page. Also, we’ve been tracking the progress of the issue in the App Feedback category in our Discourse forum. If you’re having an app issue, always check there for possible enlightenment.

Tuesday

Much of our region outside the urban core of Houston, and away from the coast, has fallen into the 30s this morning. It is quite chilly, although for virtually everyone it remains above freezing. Already light winds have already shifted to come from the east, and will soon shift from the south. Thus we will begin a warming trend that will persist into the weekend before another front arrives.

With sunny skies, temperatures today will rise into the mid-60s for much of Houston. Humidity levels will remain relatively low, and temperatures tonight will drop to around 50 degrees in the city, with slightly cooler conditions for outlying areas.

Wednesday and Thursday

A weak front on Wednesday will slow down a full-on warming trend. Accordingly, Wednesday and Thursday should be pleasant days with mostly sunny skies and highs in the low- to mid-70s. Humidity will be reasonably low, and nights should be in the 50s. With partly to mostly sunny skies, these should be mild, very pleasant days.

Friday and Saturday

With a more robust onshore flow setting up later in the week, these should be partly sunny and warmer days, with highs generally in the upper 70s. As dewpoints push upward to about 60 degrees, it will feel modestly humid. Nighttime lows will probably only fall to around 60 degrees. Rain chances, as they are all week, will remain near zero. By later on Saturday or Saturday night we’ll be on the lookout for the arrival of a stronger front.

Sunday and next week

In the big picture, a large slug of very cold Arctic air is going to surge into the midwestern United States by Friday and Saturday this week. We are talking about lows in the vicinity of -15 to -20 degrees in places like Illinois and Iowa by Sunday morning. The thing we have been watching down here in Texas is how far this very cold air will reach, or whether it will largely be shunted away from us to the east.

I don’t have 100 percent confidence, but at this point I think we are at least going to see a glancing blow. This won’t be a full-on Arctic front therefore, but even a glancing blow with this airmass should cool us down. Some of the more aggressive AI modeling brings us all the way down into the 30s by Monday morning, whereas some of our more conventional models are warmer.

Anyway, at this point I think the front will probably move in some time on Sunday, roughly. This will introduce some rain chances, but I’d bet Sunday is still at least partly sunny. Let’s go with highs in the 60s and then lows (roughly speaking) in the 40s on Sunday night. The early part of next week looks chilly, and we also might see some additional, mostly light rain showers as moisture overruns the lower levels of the atmosphere. Conditions likely warm up during the second half of the week.

A message from Reliant

Reliant is helping Houston light up the holidays and give to those in need.

Through the concourse and onto the field, to Daikin Park we go! Have an Orbit-obsessed family member? Reliant has teamed up with the Houston Astros to create a picture-perfect moment with everyone’s favorite alien mascot at Houston’s newest holiday celebration, Astros Light Up the Park. Use your photo for your holiday card or give it to the biggest Astros fan in your life! Orbit brings his signature silliness and Astros pride to Monday nights only, so don’t miss your chance for a festive photo-op. Date-specific tickets through January 4 can be purchased at https://www.mlb.com/astros/tickets/light-up-the-park.

If you want to get into the giving spirit, join Reliant in supporting the KHOU 11 Secret Santa Toy Drive. KHOU 11 is leading the charge with The Salvation Army, Reliant and others to give the gift of holiday memories and bring joy to those who need it most this time of year. You can donate by visiting The Salvation Army website or drop off new, unwrapped toys at a variety of locations throughout Houston no later than Saturday, December 13.

Reliant is committed to giving back and making a positive impact in communities across Houston. We’re thankful to celebrate with you and help light up Houston during this festive season. May your holidays be bright, jolly, and full of cheer! #ReliantLightsYourHolidays