Thread by @mattlanza

A couple thoughts on this upcoming winter storm for #Houston. We are now entering the timeframe where forecasting specifics gets modestly more comfortable. Models have been almost uncomfortably stable with the general theme of this storm for 2+ days now. 1/11

North of I-10 this looks like it'll be mostly snow and some sleet, but it's obviously tricky until we get super close in. South of I-10 this looks like mostly sleet and snow with a little freezing rain. 2/11

Meteorologically, the soundings, the vertical profile of the atmosphere strongly suggest sleet and snow as the dominant precipitation types. Less so freezing rain. This is good news so let's hope it continues. 3/11

When the storm starts, temperatures will be warm, and there will likely be plain rain. Refrain from screaming "bust!" The atmosphere is expected to cool considerably on Monday night, allowing rain to change to sleet and snow overnight. 4/11

The NWS forecast is a reasonable first call on snow totals. However, I think the risk this time around may be asymmetrically skewed toward *more* snow than shown here. That rarely happens in SE Texas. 5/11

I am especially eyeing the area east of I-45 and north of I-10, where someone could, in theory, receive anywhere from 6 to 8 inches of snow, which is a lot for this region. For Louisiana, this may be a bit of an historic snowstorm (high end risk shown here). 6/11

That said, sleet is very important in all this because that can absolutely destroy a snow forecast. Models may think 6" of snow falls somewhere, but if it's all sleet, it's like 1-2" or so. That's certainly a forecast risk. 7/11

Storms like this tend to have mesoscale banding and potentially a deformation zone, which are areas where very heavy snow can occur. In addition to 1"+ per hour snowfall rates, thunder is possible. 8/11

If this forecast holds, you will want to stay put on Tuesday. Like, for real. Travel would be nearly impossible. And with the coldest night after the storm, travel on Wednesday AM probably won't be much better. 9/11

Yes, there's a good chance your flight will be canceled after 9 PM Monday. No, I don't know when air travel would resume. But suffice to say, if you have anything planned Tues or Wed, have a solidified alternative plan in place. 10/11

The good news in all this is that it's not a TX-wide event, so this is nowhere near a Feb 2021 type event. This is a unique winter storm local to SE Texas and points east. Prepare for significant travel disruption. More to come. 11/11

One last point: Storms like this, particularly because of the banding, can have varying totals. One area could see 1-2" and less than 5 miles away has 6". Consider the forecast at this point to be a general "average," with some places likely to see more and others less. (12/11)