Texas Winter 2020-2021

[Ralph's Weather]

Nothing like heading into one of these events with a good, old fashioned low bust...https://uploads.tapatalk-cdn.com/20210109/13694e2fd6a120bae19229eebb4f41a8.jpg


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24 here. That is great the day before a snow event.

[SouthernMet]

12z HRRR stays consistent with the 6z run. 6” for Dallas 8” for Fort Worth. HRRR is sniffing out potential back-building + training bands over the metroplex even as far north as Denton & Wise counties. It lingers light snow around until around 5am Monday morning. This is a good sign for higher totals if this verifies. Let’s see if this trend continues into tonight before radar lights up in realtime.

[gboudx]

I see no changes in the FWD NWS graphics except time stamps when they were generated. Still saying most of metroplex has a low chance of seeing accumulating snow. I haven’t read the AFD because I don’t have time this morning. Maybe they’re seeing what txtwister was posting.

[Ntxw]

12z HRRR stays consistent with the 6z run. 6” for Dallas 8” for Fort Worth. HRRR is sniffing out potential back-building + training bands over the metroplex even as far north as Denton & Wise counties. It lingers light snow around until around 5am Monday morning. This is a good sign for higher totals if this verifies. Let’s see if this trend continues into tonight before radar lights up in realtime.

This has 2010 busted forecast potential written all over it. Will they stick with an inch and you look out the window and inch falls in the first 10 mins? Do you go with the globals and ignore the hi res? The RAP back in the day nailed that. This is where you earn your money!

[Ntxw]

12z HRRR stays consistent with the 6z run. 6” for Dallas 8” for Fort Worth. HRRR is sniffing out potential back-building + training bands over the metroplex even as far north as Denton & Wise counties. It lingers light snow around until around 5am Monday morning. This is a good sign for higher totals if this verifies. Let’s see if this trend continues into tonight before radar lights up in realtime.

This has 2010 busted forecast potential written all over it. Will they stick with an inch and you look out the window and inch falls in the first 10 mins? Do you go with the globals and ignore the hi res? The RAP back in the day nailed that. This is where you earn your money!

Regardless of what happens after, even taking the OPs into consideration the initial band to me looks very intense just about on every guidance. It alone in my opinion will easily drop 2-3 inches of snow in a hurry very early.

I'll make the call and say DFW snow drought ends 24 hours from now 3+

[orangeblood]

12z HRRR stays consistent with the 6z run. 6” for Dallas 8” for Fort Worth. HRRR is sniffing out potential back-building + training bands over the metroplex even as far north as Denton & Wise counties. It lingers light snow around until around 5am Monday morning. This is a good sign for higher totals if this verifies. Let’s see if this trend continues into tonight before radar lights up in realtime.

This has 2010 busted forecast potential written all over it. Will they stick with an inch and you look out the window and inch falls in the first 10 mins? Do you go with the globals and ignore the hi res? The RAP back in the day nailed that. This is where you earn your money!

Yep, 100% agreed...we’ve seen this song and dance before with a similar sypnotic setup. The Hi Res tools are extremely useful, still perplexed they’re hugging Globals. Maybe the Mets at FW NWS office weren’t around during 2010 event ?

[SouthernMet]

12z HRRR stays consistent with the 6z run. 6” for Dallas 8” for Fort Worth. HRRR is sniffing out potential back-building + training bands over the metroplex even as far north as Denton & Wise counties. It lingers light snow around until around 5am Monday morning. This is a good sign for higher totals if this verifies. Let’s see if this trend continues into tonight before radar lights up in realtime.

This has 2010 busted forecast potential written all over it. Will they stick with an inch and you look out the window and inch falls in the first 10 mins? Do you go with the globals and ignore the hi res? The RAP back in the day nailed that. This is where you earn your money!

Regardless of what happens after, even taking the OPs into consideration the initial band to me looks very intense just about on every guidance. It alone in my opinion will easily drop 2-3 inches of snow in a hurry very early.

I'll make the call and say DFW snow drought ends 24 hours from now 3+

12z NAM nearly identical to the HRRR, but with an even earlier onset of precip. 7”-10” for metro on this run.

[Ntxwx]

I’m just glad we have the S2K Winter big 3 gurus in agreement on this one it’s been too long!!! Let’s hope the models don’t back off from what they are showing now

[EnnisTx]

Looks like maybe they're starting to come around a bit.


In collaboration with neighboring offices, no changes or upgrades were made to the current Winter Storm Watch with this forecast package. It is most likely areas along and west of U.S. Highway 281 will require a Winter Storm Warning. However, there is still uncertainty on where heavier bands of snow will set up elsewhere within the Watch area, which makes it difficult to say which counties would require a Warning vs. an Advisory at this time. Regardless, residents should complete any preparations by this evening as measurable snowfall and hazardous travel conditions seem likely on Sunday across portions of North and Central Texas. By Sunday morning, ongoing precipitation across West Texas will spread east toward North and Central Texas. Although temperatures may be just above freezing near the surface during the morning hours, falling precipitation should aid in cooling the lower levels of the atmosphere to support a transition to snow. As a result, high temperatures on Sunday have been lowered slightly from guidance. A transition from a cold rain or rain/snow mix to full snow will occur initially across the Big Country during the early morning hours, by mid to late morning along the I-35 corridor, and closer to early afternoon across East Texas. The main challenges with the forecast are the potential for heavier bands of snow setting up across portions of North and Central Texas and total snowfall accumulations. As we are able to analyze high resolution data, there is increasing confidence on bands of heavier snow setting up somewhere across the Big Country and Central Texas (areas within the Watch). Some guidance extends this potential further north (as far north as a Bowie to Dallas- Fort Worth to Athens line), which is possible given where high resolution data depicts pockets of frontogenetical forcing and steepening lapse rates. Based on what we know, we expect accumulations upwards of 2" across the Big Country and Central Texas, with amounts closer to 4-6" (and localized higher amounts) west of U.S. Highway 281. Forecast snow accumulations along and north of a Bowie to Dallas-Fort Worth to Canton line are around or less than 1.5" and decrease further north, but these values may change as we determine where bands of heavier snow set up closer to the event. HREF members highlight the potential for a large swath of at least 2-4" snow accumulation across most of the region, which will be something to keep an eye on as new model data arrives through the day. The system will exit the region late Sunday night, leaving North and Central Texas beneath overcast skies. Cloud cover will decrease from west to east through Monday afternoon. Monday night will be the coldest night of the week with lows in the 20s region wide due to excellent radiational cooling. Dry weather is expected through the work week with highs gradually warming into the upper 50s and lower 60s by the end of the week. Garcia &&

[Brent]

Looks like maybe they're starting to come around a bit.


In collaboration with neighboring offices, no changes or upgrades were made to the current Winter Storm Watch with this forecast package. It is most likely areas along and west of U.S. Highway 281 will require a Winter Storm Warning. However, there is still uncertainty on where heavier bands of snow will set up elsewhere within the Watch area, which makes it difficult to say which counties would require a Warning vs. an Advisory at this time. Regardless, residents should complete any preparations by this evening as measurable snowfall and hazardous travel conditions seem likely on Sunday across portions of North and Central Texas. By Sunday morning, ongoing precipitation across West Texas will spread east toward North and Central Texas. Although temperatures may be just above freezing near the surface during the morning hours, falling precipitation should aid in cooling the lower levels of the atmosphere to support a transition to snow. As a result, high temperatures on Sunday have been lowered slightly from guidance. A transition from a cold rain or rain/snow mix to full snow will occur initially across the Big Country during the early morning hours, by mid to late morning along the I-35 corridor, and closer to early afternoon across East Texas. The main challenges with the forecast are the potential for heavier bands of snow setting up across portions of North and Central Texas and total snowfall accumulations. As we are able to analyze high resolution data, there is increasing confidence on bands of heavier snow setting up somewhere across the Big Country and Central Texas (areas within the Watch). Some guidance extends this potential further north (as far north as a Bowie to Dallas- Fort Worth to Athens line), which is possible given where high resolution data depicts pockets of frontogenetical forcing and steepening lapse rates. Based on what we know, we expect accumulations upwards of 2" across the Big Country and Central Texas, with amounts closer to 4-6" (and localized higher amounts) west of U.S. Highway 281. Forecast snow accumulations along and north of a Bowie to Dallas-Fort Worth to Canton line are around or less than 1.5" and decrease further north, but these values may change as we determine where bands of heavier snow set up closer to the event. HREF members highlight the potential for a large swath of at least 2-4" snow accumulation across most of the region, which will be something to keep an eye on as new model data arrives through the day. The system will exit the region late Sunday night, leaving North and Central Texas beneath overcast skies. Cloud cover will decrease from west to east through Monday afternoon. Monday night will be the coldest night of the week with lows in the 20s region wide due to excellent radiational cooling. Dry weather is expected through the work week with highs gradually warming into the upper 50s and lower 60s by the end of the week. Garcia &&

Well they looked at a model besides the GFS progress

[txtwister78]

12z Blended model guidance snowfall totals. I also think it's important to recognize when looking at snowfall totals (I believe someone mentioned this yesterday) that the maps assume a 10:1 ratio and that isn't the case always so what you see "predicted" on the model doesn't always occur in real time. EWX also mentioned this in the early morning discussion stating "caution should be used when viewing total snowfall accumulation of individual models runs
online, as they can show a 10:1 snow to liquid ratio, not expected for this event, and also not capture the microphysics well"

[EnnisTx]

Looks like it doesn't quite make it to San Antonio.

[txtwister78]

:uarrow: Looks like it doesn't quite make it to San Antonio.

Kerrville to Austin to College Station best shot further south. Still like Central Texas Waco area NW to Abilene and Lubbock as mentioned the past 2 days for higher snow amounts.

[EnnisTx]

:uarrow: Looks like it doesn't quite make it to San Antonio.

Kerrville to Austin to College Station best shot further south. Still like Central Texas Waco area NW to Abilene and Lubbock as mentioned the past 2 days for higher snow amounts.

Yes, I believe that's a given. However, thinking that a round or two of heavy banding will make things interesting for the DFW area especially during the initial band.

Good luck to all.

[Cerlin]

https://images.weatherbell.com/model/nbm-conus/tx/total_snow_10to1/1610193600/1610323200-HTFta7NgTzQ.png

12z Blended model guidance snowfall totals. I also think it's important to recognize when looking at snowfall totals (I believe someone mentioned this yesterday) that the maps assume a 10:1 ratio and that isn't the case always so what you see "predicted" on the model doesn't always occur in real time. EWX also mentioned this in the early morning discussion stating "caution should be used when viewing total snowfall accumulation of individual models runs
online, as they can show a 10:1 snow to liquid ratio, not expected for this event, and also not capture the microphysics well"

I’d like to have a word with this blended model because there’s a little tiny hole in Denton County that doesn’t have any snow and conveniently is where my house is

[bbowman7]

What about us out here in east Texas? It seems when I started following a day or two ago, there was nothing, but it seems to be picking up some.

Can someone give me your prediction on the Longview area? I am in GIlmer, about 20 miles northwest of Longview.

Exciting next day or two!!!

[rwfromkansas]

We have added almost 40 pages since last weekend. Wow.

[TheProfessor]

12z HRRR stays consistent with the 6z run. 6” for Dallas 8” for Fort Worth. HRRR is sniffing out potential back-building + training bands over the metroplex even as far north as Denton & Wise counties. It lingers light snow around until around 5am Monday morning. This is a good sign for higher totals if this verifies. Let’s see if this trend continues into tonight before radar lights up in realtime.

This has 2010 busted forecast potential written all over it. Will they stick with an inch and you look out the window and inch falls in the first 10 mins? Do you go with the globals and ignore the hi res? The RAP back in the day nailed that. This is where you earn your money!

Yep, 100% agreed...we’ve seen this song and dance before with a similar sypnotic setup. The Hi Res tools are extremely useful, still perplexed they’re hugging Globals. Maybe the Mets at FW NWS office weren’t around during 2010 event ?

I believe a few of them were and the ones that weren't probably know about it. We talked about it quite often while I was there. Nonetheless the SOO Ted Ryan is one of the smartest forecasters I've ever met. I've seen him nail night time thunderstorm events in the Summer while other forecasters had pops less than 20 just because he understands the physics so well.

Here's the issue with forecasting a major snow event (or winter weather in general) in DFW. In a way it's almost like forecasting a tornado outbreak in the southeast, there's typically some failure modes that the models sometimes miss. One of them is the heat island effect. Now this is usually minimized when a storm is passing through, but the effect is still there. It could be attributing to the poor low level lapse rates I've seen on some of the skew-ts. The other one is that dry air can be very sneaky and underestimated on the models. If the temperature is colder than expected then you must be wary of that. Some of the CAMs do have problems with this and will sometimes overdue precipitation in these events.

I do think this low is similar to the 2010 storm, this means that the best dynamics will be directly below and near the low. If we want to talk about fairness, Waco missed out by a few miles from the 2010 storm, so if they end up getting crushed this go around that's a nice prize. At this point it does seem like DFW will be putting all their hope into banding and in that case there's going to be some really happy people and some really sad people. There will be some insane cutoffs and it wouldn't surprise me if there were one to two bands of 4"+ in DFW with less than a half inch outside of those bands. That makes the forecast very tricky for FWD and issuing wide spread watches would be a problem. Instead we may see something like the March 2015 snow event where the NWS issues a winter storm warning for a couple of counties like they did with Denton and Collin county after training snow bands had become apparent.

[Ntxw]

Adding in my two cents regarding the GFS. So ready for it to be upgraded yet again. You would think after so many upgrades it would be better than this by now. There is no doubt now the insistent warm bias it has. That warm bias so many implications besides just snow or rain but other features that matter such as pressures as well. The fact it has went full circle is unacceptable in my mind and has been cause of headache for many that is if you know its bias, can be corrected so easily. Kudos to the short range hi res guidance for whipping it back into gear . Looks like the hi res is going to take the win. Thank goodness we have so many other tools in the box to help.

See below for the mental insanity of the GFS!

[orangeblood]

As we’ve discussed prior, globals typically come around 24-48 hrs prior once they begin getting a better feel of the convective environment and temperature profile..latest GFS is starting to do exactly that, would expect the other globals to begin doing same soon