January 2026

[Cpv17]

DP is only 35° here. Got a ways to go till we get to freezing.

[jabcwb2]

My phone just alerted me to expect wintery mix at 11:15. I'm by Willowbrook.

[NWHouston]

My phone just allerted me to expect wintery mix at 11:15. I'm by Willowbrook.

Mine too but willowbrook still at 38 and not budging. I doubt we see a 6 degree drop in next two hours

[davidiowx]

I’m in Richmond and went from 38 to 39 in the last hour

[sevensix2]

Here's a windmap as arctic air splits around the Ozarks and Ouachitas and Piney Woods. The more rapid movement down the Mississippi Delta where there are far fewer trees and more farms was a revelation.

Just like large trees reduce wind in a yard or locally, trees as part of a forest or large expanse of mostly forested land alter the weather. It's a pretty cool lesson for sure.

Path of least resistance on a grand scale. Thank you for the lesson.

[tireman4]

If only the temps would drop!!! 38 for 6 hours!

We cant call it a bust since the forcast never really called for much south of conroe which is why I did not understand why they cancelled all the schools for monday but earlier today it did look like the freeze line was going to push through early enough for some wintery precipitation in the srping area. I think its pretty clear at this point we may not even freeze tonight

Good evening. The action will start late tonight into the early morning hours. As was stated before, what may or may not happen on your neck of the woods might happen in other areas. If you look at the radar out west, you will see a rain shield moving our way. That precipitation will arrive tomorrow morning, early. The freezing line is slowly making its way into our area. Those two items will interact with each other and cause a wintry mix through at leat layer Sunday morning. If I were the ISDs and college/universities, I would have called it on Friday as well. The roads, especially overpasses and flyovers, will be treacherous on Monday.

[Cpv17]

I’m in Richmond and went from 38 to 39 in the last hour

And Stratton, just a few miles N of you near Cinco Ranch is 4° colder at 35° lol

[NWHouston]

I’m in Richmond and went from 38 to 39 in the last hour

And Stratton, just a few miles N of you near Cinco Ranch is 4° colder at 35° lol

Okay what app or link is everyone getting there current temps at because weather. Com has katy and cinco ranch at 38

[tireman4]

35 in Humble

[djmike]

Is moisture going to increase along the coastal counties? I see the freezing rain blob that will miss Houston and the coast west of Houston. I don’t see much of anything heading towards Houston from the south atm. Just curious where that moisture is coming from.

[Ptarmigan]

Is moisture going to increase along the coastal counties? I see the freezing rain blob that will miss Houston and the coast west of Houston. I don’t see much of anything heading towards Houston from the south atm. Just curious where that moisture is coming from.

Upper level low pressure system and Pacific moisture.

[tireman4]

Is moisture going to increase along the coastal counties? I see the freezing rain blob that will miss Houston and the coast west of Houston. I don’t see much of anything heading towards Houston from the south atm. Just curious where that moisture is coming from.

Look to the west, near De Rio. That is what you need to focus on

[Rip76]

Tireman is correct.

[sevensix2]

My phone just allerted me to expect wintery mix at 11:15. I'm by Willowbrook.

Mine too but willowbrook still at 38 and not budging. I doubt we see a 6 degree drop in next two hours

It's on the way, temperature has dropped by 5 degrees or so out Fayetteville/La Grange direction in the past hour, go 40 miles west of there and it's below freezing. The freeze line is oriented more N/S and moving W to E. The distance from my location in Cypress (38 currently) due west to the freeze line is gradually shrinking. 34 currently in Brenham, 30 in Giddings.

I use MyRadar for quick reference, RadarScope for more in depth info.

[jasons2k]

That freeze line arrival is off. We are below or at freezing in our area and it came at 6 pm, not 9 pm.

They have the bend wrong. It's a much sharper N/S orientation west of Houston. The times for Houston metro should be pretty close, though.

Yep - it's more of a N/S than E/W line now. Some of it is warm nose mixdown. Some is divergence of cold advection.

So, I looked at some wind maps and the polar/arctic air is coming from the Midwest and moving down the plains or the Mississippi River delta. The Ozarks in MO, AR and to some extend the Ouachitas. The shadow has been bugging me a bit, because the Ozark plateau and Ouachitas are 1500 - 2500 feet high at best. The land west of OKC has this level of altitude. Not the rugged obstruction of the Rockies and the Appalachians.

Then, I found a wind energy and terrain map that provide the (now) obvious clue!

So, moving air from a physics standpoint is a fluid and this obeys those rules and even equations. Increased fluid drag would slow advection and could reduce temp drops in the "shadow," at least temporarily.

So the fluid drag of an object or terrain would look like this:

Fd = 1/2 Cd x Ap x rho[density] x v[sqr]

Sorry about the math!

Here, Cd is the coefficient of drag - how rough a surface is. The higher Cd the greater the turbulence and air drag, slowing down the movement.

Ap = the area blocking air movement of the "ruggedness."

The Ozarks are smooth, not rugged, and are a consequence of erosion of part of a plateau

I've attached the map which leads IMO to a surprising answer to this riddle -

As you can see, the Appalachians are riddled with a high Ruggeness Index or obstructions by chains of mountains rising 6500 ft tall. The Rockies have huge obstructions and cause massive turbulence (High Cd and Ap).

Note where high levels of Roughness are (high Cd) which would slow the air. Notice where the roughness of the terrain is low. As an avid map reader and traveloer I know the terrain of everything east of the Rockies pretty well. Note more limited areas of Ruggedness in the Boston Mountains and some of the Ouachitas in AR vs. the Appalacians and Rockies

Where you see high levels of Roughness (which would drag surface air and also contribute to turbulence) are areas of high forestation. The Ozarks and Ouachitas are densely populated with trees as are the Piney Woods. So, the trees are putting a draf on cold advection from the north, especially if the original source of the wind is NNE. The trees make it rough, increasing turbulence and reduction wind speed and advection on the surface.

I should point out that the trees naturally are in areas with greater rainfall and access to gulf moisture. The plains, Mississippi Delta and parts of the Midwest have far fewer trees and forestation.

The windspeed is not surprisingly high in the plains

The cold air after dark should swallow more of east Texas and catch up with areas west, moving the freeze line from west to east.

Thank you for this - this is fantastic! This explains very well what's going on.

I am going to save this to do some additional research and math after this storm is over.

[davidiowx]

I’m in Richmond and went from 38 to 39 in the last hour

And Stratton, just a few miles N of you near Cinco Ranch is 4° colder at 35° lol

Haha yea it’s pretty wild. I am back to 38.8 IMBY but I anticipate to be down close, or at freezing, after midnight. DP has been steady at 38 for the past 4-5 hours or so.

[davidiowx]

I’m in Richmond and went from 38 to 39 in the last hour

And Stratton, just a few miles N of you near Cinco Ranch is 4° colder at 35° lol

Okay what app or link is everyone getting there current temps at because weather. Com has katy and cinco ranch at 38

I have my own weather station so that is what I’m using.

[tireman4]

Jeff Lindner from Facebook

1-24-26 850pm

Freezing line advancing southeast along line from near Huntsville to Hempstead to NW of Victoria. Running about an hour or slower than expected earlier today.

Travel issues start to occur about 60 miles NW of the freeze line as it is taking a few hours for the bridges to cool to the point where ice is forming.

[BAY29]

down to 35 in tomball so it looks good

[jasons2k]

The secondary surge is pushing through. In the last hour, temps are dropping again and the wind has picked-up. Starting to gust pretty good from the NNW now.