Texas Winter 2020-2021

[Ntxw]

GFS definitely not playing along for those who want snow in Dallas area. ICON also continues a track further south. Still outliers but with the NAM coming back down to earth with totals definitely not a good trend. Interested to see what GEM, UKMET and EURO show.

GFS really develops that low off the gulf while other models are not as bullish. If the GFS is right that would really limit snowfall totals. Perhaps that's why FWD was not as bullish on totals?

For sure, the FWD tends to err on the side of the GFS even when the GFS is an obvious outlier. It really just comes down to surface temperatures. GFS isn’t showing those colder temperatures as a result of that low but really I don’t see how that low could influence temperatures in the way the GFS is suggesting, even if it does develop. In addition, both the GFS and ICON have struggled with snow systems 3 days out. When I was in Norman and we had the snow storm in December, the GFS was showing mostly rain beforehand...and there wasn’t hardly any rain. It missed surface temperatures by about 3 degrees and the ICON was relatively similar, even if it is a little more accurate sniffing some of these trends out. I would put much more stock into the NAM/Euro than the GFS at this point, just based on how well they’ve handled the systems this year.

Not so much temps with the low off the gulf. It would be the more dominant (stronger system) and phase in the "northern branch" energy coming out of NM and the Lubbock area. That's why the graphic FWD put out had the heaviest snowfall potential further west and not as much confidence further east toward Dallas. At least that's my read on it. The other models are counting on that not being as strong and with the heavier precip means more snow totals dropping temps a few more degrees than what the GFS shows. The 850 temps are just fine. All about QPF at this point.

There are instances where a big gulf surface low can cutoff our moisture source very true. But there are also instances where it isn't detrimental. A lot of the upper level dynamics are at play also. Airforcemet taught us once you follow the vorticity. Lift is equally as important and in the cold sector it doesn't take much moisture to get some inches of snow. In the infamous 2010 a surface low did form and a ton of rain fell along the coast and SE Texas and that storm took an even further south trajectory. Quality of lift matters too up north.

If we were talking just a positive tilt trough then yes automatic the gulf low would instantly shut off the faucet, luckily at the moment that is not the case yet. It was a few days ago when we were looking at suppression.

Unfortunately I couldn't get the archives for hourly or sub-hourly but the surface low did ride up the Texas coast in 2010 before heading out in the gulf. Below is the archived maps I generated from the WPC Product archives for the period. FWIW also a fun tool to use! https://www.wpc.ncep.noaa.gov/archives/web_pages/wpc_arch/get_wpc_archives.php

[EnnisTx]

For sure, the FWD tends to err on the side of the GFS even when the GFS is an obvious outlier. It really just comes down to surface temperatures. GFS isn’t showing those colder temperatures as a result of that low but really I don’t see how that low could influence temperatures in the way the GFS is suggesting, even if it does develop. In addition, both the GFS and ICON have struggled with snow systems 3 days out. When I was in Norman and we had the snow storm in December, the GFS was showing mostly rain beforehand...and there wasn’t hardly any rain. It missed surface temperatures by about 3 degrees and the ICON was relatively similar, even if it is a little more accurate sniffing some of these trends out. I would put much more stock into the NAM/Euro than the GFS at this point, just based on how well they’ve handled the systems this year.

Not so much temps with the low off the gulf. It would be the more dominant (stronger system) and phase in the "northern branch" energy coming out of NM and the Lubbock area. That's why the graphic FWD put out had the heaviest snowfall potential further west and not as much confidence further east toward Dallas. At least that's my read on it. The other models are counting on that not being as strong and with the heavier precip means more snow totals dropping temps a few more degrees than what the GFS shows. The 850 temps are just fine. All about QPF at this point.

Perhaps and time will tell. Also consider that is higher terrain and historically colder along the storm track out west and thus less rain to snow transition and more plain snow in that swath and this easier to make higher predictions. We are inside 72 hours so something is going to cave.

My wishcast if you will is the GFS just went north so it will be the one to cave but it think tomorrow will be the day to tell which set of the models cave towards the others. I did have a gulf low screw up our snow in 7th or 8th grade so I know it can happen

Elevation can be a big player as it's about 1,300' higher than we are here in the Metroplex.

[orangeblood]

0Z GEFS beginning to shift north, following much more in line with others

[EnnisTx]

For sure, the FWD tends to err on the side of the GFS even when the GFS is an obvious outlier. It really just comes down to surface temperatures. GFS isn’t showing those colder temperatures as a result of that low but really I don’t see how that low could influence temperatures in the way the GFS is suggesting, even if it does develop. In addition, both the GFS and ICON have struggled with snow systems 3 days out. When I was in Norman and we had the snow storm in December, the GFS was showing mostly rain beforehand...and there wasn’t hardly any rain. It missed surface temperatures by about 3 degrees and the ICON was relatively similar, even if it is a little more accurate sniffing some of these trends out. I would put much more stock into the NAM/Euro than the GFS at this point, just based on how well they’ve handled the systems this year.

Not so much temps with the low off the gulf. It would be the more dominant (stronger system) and phase in the "northern branch" energy coming out of NM and the Lubbock area. That's why the graphic FWD put out had the heaviest snowfall potential further west and not as much confidence further east toward Dallas. At least that's my read on it. The other models are counting on that not being as strong and with the heavier precip means more snow totals dropping temps a few more degrees than what the GFS shows. The 850 temps are just fine. All about QPF at this point.

There are instances where a big gulf surface low can cutoff our moisture source very true. But there are also instances where it isn't detrimental. A lot of the upper level dynamics are at play also. Airforcemet taught us once you follow the vorticity. Lift is equally as important and in the cold sector it doesn't take much moisture to get some inches of snow. In the infamous 2010 a surface low did form and a ton of rain fell along the coast and SE Texas and that storm took an even further south trajectory. Quality of lift matters too up north.

If we were talking just a positive tilt trough then yes automatic the gulf low would instantly shut off the faucet, luckily at the moment that is not the case yet. It was a few days ago when we were looking at suppression.

Unfortunately I couldn't get the archives for hourly or sub-hourly but the surface low did ride up the Texas coast in 2010 before heading out in the gulf. Below is the archived maps I generated from the WPC Product archives for the period. FWIW also a fun tool to use! https://www.wpc.ncep.noaa.gov/archives/web_pages/wpc_arch/get_wpc_archives.php

https://i.imgur.com/NWlPrKD.gif

https://i.imgur.com/arnPh58.gif

Smart man right there

[Cerlin]

GFS definitely not playing along for those who want snow in Dallas area. ICON also continues a track further south. Still outliers but with the NAM coming back down to earth with totals definitely not a good trend. Interested to see what GEM, UKMET and EURO show.

GFS really develops that low off the gulf while other models are not as bullish. If the GFS is right that would really limit snowfall totals. Perhaps that's why FWD was not as bullish on totals?

For sure, the FWD tends to err on the side of the GFS even when the GFS is an obvious outlier. It really just comes down to surface temperatures. GFS isn’t showing those colder temperatures as a result of that low but really I don’t see how that low could influence temperatures in the way the GFS is suggesting, even if it does develop. In addition, both the GFS and ICON have struggled with snow systems 3 days out. When I was in Norman and we had the snow storm in December, the GFS was showing mostly rain beforehand...and there wasn’t hardly any rain. It missed surface temperatures by about 3 degrees and the ICON was relatively similar, even if it is a little more accurate sniffing some of these trends out. I would put much more stock into the NAM/Euro than the GFS at this point, just based on how well they’ve handled the systems this year.

Not so much temps with the low off the gulf. It would be the more dominant (stronger system) and phase in the "northern branch" energy coming out of NM and the Lubbock area. That's why the graphic FWD put out had the heaviest snowfall potential further west and not as much confidence further east toward Dallas. At least that's my read on it. The other models are counting on that not being as strong and with the heavier precip means more snow totals dropping temps a few more degrees than what the GFS shows. The 850 temps are just fine. All about QPF at this point.

BTW definitely not saying Dallas isn't getting anything out of this. What I am saying is the GFS solution is obviously what FWD is weighting more as of now. Obviously that could change.

Yeah, I worded that badly (i meant the low pulling which would lead to warmer temperatures because of a weaker more southern low now allowing for wet bulb cooling), but I see what you’re saying and I definitely agree with the QPF being the biggest factor. I don’t blame the NWS for being conservative either as it’s definitely something that could still bust even 48 hrs out.

[Quixotic]

I’d be more worried about a coastal low if there was an arctic high instead of a polar one.

[Ntxw]

As for FW, I can't speak for them, but I would suspect any WFO would collaborate both dynamical and statistical methods. My hunch is they would probably play it safe based on probability factors, which you can also get at the WPC!

This will expand as the time period approaches closer and I would bet FW follows suit. As a forecaster that's the best thing to do, give the best certainty and note the possibility.

[Ntxw]

0z Ukmet

[Texas Snow]

0z Ukmet

https://i.imgur.com/TtGVGFu.png

That little dig in Southwestern Collin County (the one above Dallas) is persistent across multiple models where QPF is lower in an axis there and continues northeast.

I know this far this far out not to read to much into snow outputs, but since I live so close to that area it is a little concerning as it is consistent model to model and run to run. Very interesting if it actually plays out that way and why.

[Ntxw]

0z Ukmet

https://i.imgur.com/TtGVGFu.png

That little dig in Southwestern Collin County (the one above Dallas) is persistent across multiple models where QPF is lower in an axis there and continues northeast.

I know this far this far out not to read to much into snow outputs, but since I live so close to that area it is a little concerning as it is consistent model to model and run to run. Very interesting if it actually plays out that way and why.

Just take the two and half inches and run .

[txtwister78]

CMC ENS likes Central Texas again. Higher totals further south.

[Texas Snow]

0z Ukmet

https://i.imgur.com/TtGVGFu.png

That little dig in Southwestern Collin County (the one above Dallas) is persistent across multiple models where QPF is lower in an axis there and continues northeast.

I know this far this far out not to read to much into snow outputs, but since I live so close to that area it is a little concerning as it is consistent model to model and run to run. Very interesting if it actually plays out that way and why.

Just take the two and half inches and run .

Well I was more interested in the why but since I’m actually in the 3” zone I should just shut up and lock that in rather than getting greedy.

[txtwister78]

Euro coming in a tad bit south from its previous run. Higher totals south of DFW closer to Waco area (close to 7 inches SW of DFW)

[Brent]

Euro looks like it hits a wall around northeastern DFW

[Ntxw]

Euro looks like it hits a wall around northeastern DFW

https://i.ibb.co/8dbCqhp/sn10-acc-us-sc-24.png

Looks pretty close to 12z . It actually NAM'd a little bit at 72 hours and jogged to the North at 72 hours @ 500mb. QPF is a little bit weaker like the NAM on the n side so everyone loses a little.

[Haris]

Euro shows 1” at Austin. Hey if that happens, I’ll be extremely happy. Please lord

[starsfan65]

That system is still in the Pacific Ocean. We will know more about it tomorrow.

[Cerlin]

Can’t really explain the snow hole for eastern DFW there...

[Brent]

Can’t really explain the snow hole for eastern DFW there...

I'm a little wondering why most of the 0z models seem less enthused overall

It could just be a blip but who knows I'm paranoid lol so many runs left

[Ntxw]

That system is still in the Pacific Ocean. We will know more about it tomorrow.

We have a good footing on where it will snow. The model nitpicking is on how much and where it is highest (we knew this would happen ). We won't have full idea until radar pops Sat night.