Texas Winter 2020-2021

[SouthernMet]

I feel like it’s a dangerous game hoping the extended HRRR is showing a new trend.

The storm should be sampled now and especially by the 00z runs tonight. So it will be interesting to see what the 18z and 00z runs look like.

I would not say HRRR is a trend. It's pretty on par with the initial band of snow that moves through early in the game from all the models, Sunday morning period is going to snow in DFW. The question is after does it continue to snow or the qpf shift southward for bigger totals.

100% agree. I don’t believe you could ever call one model run a trend. Also, I feel the HRRR looks nice but hr 48 of the HRRR is probably unreliable.

One model run? The HRRR (just now in range) is in agreement with the RGEM, SREF, UKMET & 12km NAM.

[Portastorm]

This from this afternoon's discussion from NWS Austin/San Antonio ... the more you know:

One thing to note is to be careful when looking at model snow
accumulation forecast graphics online. The algorithms that calculate
this field fail to look at microphysics related to snow production in
the dendritic growth zone of -10c to -20c. Snow depth graphics can be
better to look at in this case as they do account for microphysics.
For example the ECMWF shows 3-4 inches for our northern counties of
snow fall but only about an inch of snow depth.

[orangeblood]

NAM is going towards what the SREF members have been saying for several runs now...this is very reminiscent of Feb 2010 with almost every Global doing their exact same shenanigans. There's a lot of moving parts that these globals are having a difficult time with.

18Z NAM

[rwfromkansas]

I will pay $100 bucks for the NAM (low-res) to verify. Heck, many happy folks with that. Lol. I literally put my hand on the computer monitor and compared it to the previous run and definitely shows a northward AND critically an eastward expansion of QPF. Maybe showing a weaker gulf low. The orientation of the highest QPF is slightly more east than previously. Overall, it hasn't really moved north, just expanded a bit. Will see. I think we will know more tonight since the 0Z run will get more solid data ingested. Then what will be will be. Let's just say, I have gotten very little work done today. I forgot to add that there is a bit of a north expansion on the high-res NAM, too.

[Brent]

I love how the winter storm watch is between DFW and Austin

[rwfromkansas]

That's intriguing. I have always wondered why snow depth graphics are always much less than the other maps even right after falling.

This from this afternoon's discussion from NWS Austin/San Antonio ... the more you know:

One thing to note is to be careful when looking at model snow
accumulation forecast graphics online. The algorithms that calculate
this field fail to look at microphysics related to snow production in
the dendritic growth zone of -10c to -20c. Snow depth graphics can be
better to look at in this case as they do account for microphysics.
For example the ECMWF shows 3-4 inches for our northern counties of
snow fall but only about an inch of snow depth.

[Ntxw]

I love how the winter storm watch is between DFW and Austin

I've seen them issue winter watches for much less .

[EnnisTx]

I love how the winter storm watch is between DFW and Austin

I've seen them issue winter watches for much less .

I like what you did there.

[Captmorg70]

I would not say HRRR is a trend. It's pretty on par with the initial band of snow that moves through early in the game from all the models, Sunday morning period is going to snow in DFW. The question is after does it continue to snow or the qpf shift southward for bigger totals.

100% agree. I don’t believe you could ever call one model run a trend. Also, I feel the HRRR looks nice but hr 48 of the HRRR is probably unreliable.

One model run? The HRRR (just now in range) is in agreement with the RGEM, SREF, UKMET & 12km NAM.

Just my opinion,

But I felt like how the 18z HRRR handled the coastal low and the banding out front of the storm was different then what the 6z and 12z models had shown.

I was initially replying to someone about how that one run isn’t a trend.

[losf1981]

NAM is going towards what the SREF members have been saying for several runs now...this is very reminiscent of Feb 2010 with almost every Global doing their exact same shenanigans. There's a lot of moving parts that these globals are having a difficult time with.

18Z NAM
https://images.weatherbell.com/model/nam-218-all/tx/total_snow_10to1/1610128800/1610409600-wmbtv98DVh4.png

I want to throw up.

[orangeblood]

Wow, that DGZ looks primed on the latest 18Z Hi Res NAM forecast sounding throughout the Metroplex....

[Ntxw]

Wow, that DGZ looks primed on the latest 18Z Hi Res NAM forecast sounding throughout the Metroplex....

https://www.tropicaltidbits.com/analysis/models/sounding/images/nam3km_2021010818_fh51_sounding_32.77N_97.14W.png

This is quite an unusual system. It's so cold aloft you typically see that sounding in a much colder air mass. It is deep polar air mass for sure but not arctic in nature so to have it like that is strange.

[orangeblood]

Wow, that DGZ looks primed on the latest 18Z Hi Res NAM forecast sounding throughout the Metroplex....

https://www.tropicaltidbits.com/analysis/models/sounding/images/nam3km_2021010818_fh51_sounding_32.77N_97.14W.png

This is quite an unusual system. It's so cold aloft you typically see that sounding in a much colder air mass. It is deep polar air mass for sure but not arctic in nature so to have it like that is strange.

Yep, just look at the cross-sectional view of this airmass from 12pm Sunday to 12pm Monday....not a lot of rain falling in an airmass like that!! If the moisture is there, watch out below!!

[txtwister78]

18z ICON really drops snowfall totals and increases the intensity of the low in the gulf robbing many across North Texas of much in the way of snow at all. This is similar to what the GFS has been hinting at. Definitely something to keep an eye on. Not ready to buy into that yet. I do think Porta posted an important statement from EWX regarding accumulations.

I think the NAM and RGEM are a bit overdone for example.

[Haris]

Holy moly

[BTAYLOR5021]

No WSW for DFW. Does this mean ince again little to no snow? Someone please advise.

[SnowintheFalls]

FWIW, I feel like DFW will get some substantial snow out of this system. Up here on the Red River seems to be a little more on a razor thin edge. I have a feeling we will have to wait until Sunday to see if we get anything the way the models have been.

[Ntxw]

FWIW, I feel like DFW will get some substantial snow out of this system. Up here on the Red River seems to be a little more on a razor thin edge. I have a feeling we will have to wait until Sunday to see if we get anything the way the models have been.

I think even folks in the Falls have a shot at snow and it never takes much to put some snow in WF. Don't get lost in the back and forth with amounts, since that discussion is who gets the most. The Red River's best shot is with the actual ULL itself.

[gpsnowman]

No WSW for DFW. Does this mean ince again little to no snow? Someone please advise.

This has happened numerous times. Watches and warnings get hoisted to the north and west of DFW only to see the Metroplex finally included later on. Will it happen again? At least a watch is a good bet for tomorrow.

[Captmorg70]

No WSW for DFW. Does this mean ince again little to no snow? Someone please advise.

I think you’d have to be a wizard to accurately give an answer.

Not having a winter storm watch at this moment doesn’t mean no snow will occur.

If I’m being honest, I feel like I’ve seen more snow when watches weren’t posted than when they were.