January 2026

[BAY29]

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

[tsb2107]

32 at IAH - not sure if we make my prediction.

[jasons2k]

ABC 13

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.

[jasons2k]

It’s 32 in Beeville. It’s diving south, to the west of here.

[BAY29]

Are the temps gonna start to budge soon?

[Rip76]

Looking at radar, there’s a lot of precip out there.

[Stratton20]

HRRR suggests thunder sleet in houston, that would be crazy!

[Cpv17]

HRRR suggests thunder sleet in houston, that would be crazy!

Not sure I’m gonna get much sleep tonight

[MontgomeryCoWx]

29 here and frz fog

[Stratton20]

Cpv17 oh im not at all , i rarely pull all nighters, winter storms are definitely the exception lol

[DoctorMu]

ABC 13

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.

[Cpv17]

37° here now.

[Cromagnum]

Sleeting pretty good off and on over here now and looks to go on for a long while.

[DoctorMu]

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.

[Cpv17]

29 here and frz fog

Crazy that you only live 45 min from me now and you’re 8° colder lol

[DoctorMu]

Sleeting pretty good off and on over here now and looks to go on for a long while.

Hope we see sleet instead of freezing rain!

[MontgomeryCoWx]

29 here and frz fog

Crazy that you only live 45 min from me now and you’re 8° colder lol

Mother Nature has no rules, eh?

[DoctorMu]

31°F and ice fog in CLL.

[NWHouston]

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

[Stratton20]

I have to disagree respectfully , im 30 minutes west of houston in katy and we just dropped another 1-2 degrees this hour, down to 35, south of houston also isnt in the clear either