Texas Winter 2017-2018

[Portastorm]

Whew! Just got back from an early-morning bike ride (sleeveless jersey/shorts). Wanted to get back to the house before it got too hot (above 40). Looking at all the data, here's what I'm thinking about Tuesday's event. I think that the DFW area will see SOME snow. Accumulations most likely between a trace and 1/2 inch. Wouldn't rule out up to an inch, but moisture still looks limited that far north.

For Portastorm & others in the Austin area, the front moves through early Tuesday morning. Temperature drops below freezing at the surface before sunrise. However, there will likely be an above-freezing layer aloft between 4000-7000 ft. With most of the precip column in above-freezing air, this points to precip starting out as light rain then changing to freezing rain and sleet. By 9am, temps at the surface will be well below freezing with moderate precip falling. The above-freezing layer will be around 5000-7000 ft but the precip column is deeper, meaning more sleet than freezing rain. By noon, most of that warm tongue aloft is gone but the moisture and precip are trailing off. I think the precip will finish up as snow there, but if models are correct, that warm layer aloft won't allow for much in the way of accumulations. More moisture than in the DFW area, but warmer aloft. Less than an inch of snow in Austin.

Here in Houston, cold rain is most likely. Quite a warm tongue aloft, much more so than Austin. This is NOT a snow setup for Houston. Freezing rain, if anything.

Thanks for the analysis, wxman57. While many of you are hoping for snow ... I think most folks in my part of the state are just hoping to avoid a major ice storm. No one here really expects an accumulating snowfall. But we do expect a nasty wintry mix which should coat the bridges and overpasses and some surface roads ... and, as srainhoutx wrote earlier, a "travel nightmare."

[dhweather]

12Z GFS holds out a little hope for the Meteoplex, south of I20 looks better.

[katheria]

Correct me if i am wrong..but didnt the famous snowmegadon also show limited moisture on the models?
Trying to find all the posts from the event...

[cheezyWXguy]

I am curious what kind of snow ratio we would be dealing with in the metroplex. Temps will probably be between 23 and 26 degrees during majority of time when snow is falling, which seems like it would carry a higher ratio than the typical 1:10 we see with fat, wet flakes around 32 degrees.

[JayDT]

Just saw a pic on twitter of the 6z GFS Ensembles & each member showed some kind of wintry precip here in DFW

[katheria]

I am curious what kind of snow ratio we would be dealing with in the metroplex. Temps will probably be between 23 and 26 degrees during majority of time when snow is falling, which seems like it would carry a higher ratio than the typical 1:10 we see with fat, wet flakes around 32 degrees.

I would guess 15:1

[downsouthman1]

Whew! Just got back from an early-morning bike ride (sleeveless jersey/shorts). Wanted to get back to the house before it got too hot (above 40). Looking at all the data, here's what I'm thinking about Tuesday's event. I think that the DFW area will see SOME snow. Accumulations most likely between a trace and 1/2 inch. Wouldn't rule out up to an inch, but moisture still looks limited that far north.

For Portastorm & others in the Austin area, the front moves through early Tuesday morning. Temperature drops below freezing at the surface before sunrise. However, there will likely be an above-freezing layer aloft between 4000-7000 ft. With most of the precip column in above-freezing air, this points to precip starting out as light rain then changing to freezing rain and sleet. By 9am, temps at the surface will be well below freezing with moderate precip falling. The above-freezing layer will be around 5000-7000 ft but the precip column is deeper, meaning more sleet than freezing rain. By noon, most of that warm tongue aloft is gone but the moisture and precip are trailing off. I think the precip will finish up as snow there, but if models are correct, that warm layer aloft won't allow for much in the way of accumulations. More moisture than in the DFW area, but warmer aloft. Less than an inch of snow in Austin.

Here in Houston, cold rain is most likely. Quite a warm tongue aloft, much more so than Austin. This is NOT a snow setup for Houston. Freezing rain, if anything.

Thanks for the analysis, wxman57. While many of you are hoping for snow ... I think most folks in my part of the state are just hoping to avoid a major ice storm. No one here really expects an accumulating snowfall. But we do expect a nasty wintry mix which should coat the bridges and overpasses and some surface roads ... and, as srainhoutx wrote earlier, a "travel nightmare."

Unfortunately, said "travel nightmare" seems to be trending more as we get closer to the event.

[stormlover2013]

What’s bad models still struggling!!!

[orangeblood]

12Z GFS holds out a little hope for the Meteoplex, south of I20 looks better.

Trends are pointing towards a trace to 1/2 inch across DFW (even the most aggressive model is maybe an inch now), 1-2 " from Waco to Texarkana.

[Ralph's Weather]

I am curious what kind of snow ratio we would be dealing with in the metroplex. Temps will probably be between 23 and 26 degrees during majority of time when snow is falling, which seems like it would carry a higher ratio than the typical 1:10 we see with fat, wet flakes around 32 degrees.

I would guess 15:1

And could push even above that Tuesday morning as precip winds down. Which is why significant snow is on the table though moisture is limited. This is more of something typically seen up north on the Plains. With sustained winds over 20 mph and dry snow it will likely blow around pretty good as well as create drifts.

[wxman22]

12z GFS is more aggressive it looks similar to the icon model. It shows 18 hours of frozen precip in the Austin area, and 12 hours of frozen precip in the Houston area.

[EnnisTx]

12z German ICON model is much wetter and snowier across a large part of TX. Snowiest run yet. I've been pretty impressed with this model so far. Curious to see how it performs with this event.

Deutschland Uber Alles!!!!

Ich liebe das.

Gut Scheiße, lass es hoffen, es bestätigt !!

[bubba hotep]

00z Euro and EPS both agree on about 1" of snow at DFW using 10:1 ratio with totals increasing as you head NE towards the ArkLaTx. The American models are genearlly drier and shifted south with the precipitation. I'm going with the Euro in this setup and higher ratios, so I will go with a call of 1.5 - 2" at DFW with totals increasing as you head NE.

[orangeblood]

12z GFS is more aggressive. It shows 18 hours of frozen precip in the Austin area, and 12 hours of frozen precip in the Houston area.

Actually, this run has less precip across the state...not as much moisture and Dry Arctic front really doing its dirty work on drying out the atmosphere. It does have more frozen precip towards the coast though

[bubba hotep]

I don't have UK data but the CMC and ICON both agree more with the Euro than the American models as far as QPF placement.

[Ntxw]

I don't have UK data but the CMC and ICON both agree more with the Euro than the American models as far as QPF placement.

Yeah generally its the american models vs international guidance. UK yesterday looked dry but its data is limited so hard to tell

Will be interesting if the Euro holds ground with the CMC. We're still talking light qpf overall but so cold, small shifts matter. 0.1 liquid vs 0.2 or 0.3

[stormlover2013]

Cmc is dry for south east tx, German model isn’t, Gfs isnt, models models

[bubba hotep]

I am curious what kind of snow ratio we would be dealing with in the metroplex. Temps will probably be between 23 and 26 degrees during majority of time when snow is falling, which seems like it would carry a higher ratio than the typical 1:10 we see with fat, wet flakes around 32 degrees.

I would guess 15:1

Ratios well be higher than typical at some point but DFW will lose some QPF to rain and lower ratios as the column cools. The timing of that makes all the difference. The Euro QPF is about 0.20" at DFW, so there is not a lot of room for cooling errors. In a perfect setup that starts as all higher ratio snow we could see 3"+ but that won't happen so working backwards is how I see 1.5-2" for DFW.

[Ntxw]

Here is the cmc accounting for ratios. I think its overdone some since its usually a few degrees too cold with amounts but coverage is similar to prior runs and Euro

[Lagreeneyes03]

This looks like a big bummer for north of DFW Seems like we have had a lot of cold this winter up this way, but can’t get any precipitation

Another one of those "too cold to snow" situations. This winter has turned out to be a big ol Winter Cancel in my book. It's not winter unless we get a good sleet or snow storm for me.