East Tennessee Weather II

[BigOrangeMojo]

Last time we had no risk, we had an EF2 with no warning hit the Cedar Bluff area.

You had a risk that day...

 

[Burhead]

Euro is king as always however all models are now showing a Miller A with totals rising each run. MRX discussion will be interesting this afternoon.

What is a miller a for us weather idiots?

 

[hUTch2002]

Ok, the GFs has officially gotten out of control for East TN. No way this is correct.

 

[davethevol]

You had a risk that day...

View attachment 609548

I guess I misremembered. We didn’t get any tornado warning before it hit though.

 

[BigOrangeMojo]

I guess I misremembered. We didn’t get any tornado warning before it hit though.

They completely blew no TorWarn on the EF2. That, especially on an Enhanced/Moderate risk day, is a huge miss...

 

[volsarelife1]

Ok, the GFs has officially gotten out of control for East TN. No way this is correct. View attachment 609575

Going to be very interesting. Got the two separate systems occurring with the Monday/Tuesday system and the Friday system next week.

 

[hUTch2002]

Going to be very interesting. Got the two separate systems occurring with the Monday/Tuesday system and the Friday system next week.

I hope it’s right, I just find it really hard to believe we’re going to see a foot of snow on the ground.

 

[BigOrangeMojo]

Please don’t say that ugh. What changed?

For Memphis


The Euro model has been the driest model with most of its precip in North-Central MS.

The 00Z GFS flip flopped and had its driest run with most of the heaviest precip in Northern MS. The 06 and 12Z are wetter and with heaviest bands a little further north in MS (As a result, this is more for Shelby Co)

Most recent Euro is a little further north with heaviest precip and a little wetter than prior couple of runs.

Looking like Northern MS may get a good snowfall out of this....

 

[Burhead]

For Memphis


The Euro model has been the driest model with most of its precip in North-Central MS.

The 00Z GFS flip flopped and had its driest run with most of the heaviest precip in Northern MS. The 06 and 12Z are wetter and with heaviest bands a little further north in MS (As a result, this is more for Shelby Co)

Most recent Euro is a little further north with heaviest precip and a little wetter than prior couple of runs.

Looking like Northern MS may get a good snowfall out of this....

Thanks for answering my stupid questions so it looks like the models are back to saying a good snow for us west TN folks again?

 

[hUTch2002]

Thanks for answering my stupid questions so it looks like the models are back to saying a good snow for us west TN folks again?

Forget West. We want snow East! If you’re nice we might share though.

 

[rocktopper16]

Ok, the GFs has officially gotten out of control for East TN. No way this is correct. View attachment 609575

Not exactly, some model ensembles have shown 10inches or greater. Trends are still happening but with those so is our accumulation. I’m trying to remain level headed but it’s got me pretty excited.

 

[rocktopper16]

Thanks for answering my stupid questions so it looks like the models are back to saying a good snow for us west TN folks again?

Yes. It looks to be that way as of now. Hopefully the models have came to a solution. Euro trended with GFS and ICON on its latest run besides QPF amounts. NWS is increasing odds for snowfall amount quietly too.

 

[MetVol]

Not exactly, some model ensembles have shown 10inches or greater. Trends are still happening but with those so is our accumulation. I’m trying to remain level headed but it’s got me pretty excited.

It's hard not to get excited when the ensembles have jumped on board today like they have, too. We're looking at a potential winter storm with significant snow amounts and brutal cold.



(These ensemble outputs are 10:1 ratios which are probably too low based on the current setup.)

Still, we're 72 hours out and much can change. A stronger system and TROWAL could even get us some sleet or fzra mixing in. That's not necessarily likely, but I've seen a lot changes happen, for better and worse, in that last 48 hours prior to an event.

 

[BigOrangeMojo]

Forget West. We want snow East! If you’re nice we might share though.

Thanks for answering my stupid questions so it looks like the models are back to saying a good snow for us west TN folks again?

NWS just hoisted up Winter Storm Watch for entire Mid South (Memphis area)

3-8 inches expected in Watch Area.

 

[hUTch2002]

Not exactly, some model ensembles have shown 10inches or greater. Trends are still happening but with those so is our accumulation. I’m trying to remain level headed but it’s got me pretty excited.

Oh yeah, I’m trying to keep the excitement down but it’s getting difficult now.

 

[hUTch2002]

It's hard not to get excited when the ensembles have jumped on board today like they have, too. We're looking at a potential winter storm with significant snow amounts and brutal cold.

View attachment 609640
View attachment 609642
(These ensemble outputs are 10:1 ratios which are probably too low based on the current setup.)

Still, we're 72 hours out and much can change. A stronger system and TROWAL could even get us some sleet or fzra mixing in. That's not necessarily likely, but I've seen a lot changes happen, for better and worse, in that last 48 hours prior to an event.

Ok, sorry to be the dumb one here, how the hell do you read that thing?

 

[MetVol]

Ok, sorry to be the dumb one here, how the hell do you read that thing?

Sorry about that! The top part is the GFS and ECMWF ensemble members showing accumulated snow for each ensemble member from the current time (left) to a time in the future as you move right. The bottom chart on each image is the ensemble mean compared to the deterministic model solution showing accumulated snow through time.

 

[hUTch2002]

Sorry about that! The top part is the GFS and ECMWF ensemble members showing accumulated snow for each ensemble member from the current time (left) to a time in the future as you move right. The bottom chart on each image is the ensemble mean compared to the deterministic model solution showing accumulated snow through time.

Not sure what that means relative to the bottom chart so let’s stick with the top. I’m taking it that having the pinks and purples at the bottom of the chart is why you’re saying the ensembles are on board now. In other words, that 50 on the top left means that row was the run 50 hours ago, correct?

 

[MetVol]

Not sure what that means relative to the bottom chart so let’s stick with the top. I’m taking it that having the pinks and purples at the bottom of the chart is why you’re saying the ensembles are on board now. In other words, that 50 on the top left means that row was the run 50 hours ago, correct?

The 50 is actually the number of the ensemble member. So there's about 50 total ensemble members and the deterministic control member. It's basically just a way of showing that nearly all of the ensemble members are on board with some decent snow now. It's a probabilistic way of looking at the likelihood of snow. The timeline for both charts is actually at the very bottom of each image with the further right you go on both charts moving further into the future of the model/ensemble run.

 

[hUTch2002]

The 50 is actually the number of the ensemble member. So there's about 50 total ensemble members and the deterministic control member. It's basically just a way of showing that nearly all of the ensemble members are on board with some decent snow now. It's a probabilistic way of looking at the likelihood of snow. The timeline for both charts is actually at the very bottom of each image with the further right you go on both charts moving further into the future of the model/ensemble run.

Ah, I see. So about half of the members have us at 6+ inches. That’s nice.

 

[norrislakevol]

NWS just hoisted up Winter Storm Watch for entire Mid South (Memphis area)

3-8 inches expected in Watch Area.

I'm gonna take a wild guess and say that all of east Tennessee, except for the far southern counties bordering other states will fall under a winter storm watch as well come Saturday night, or at latest, Sunday Morning. I'm going to go with 3 to 6 inches possible snowfall accumulations if the models stay steady....some places will see a little more.

 

[norrislakevol]

The 50 is actually the number of the ensemble member. So there's about 50 total ensemble members and the deterministic control member. It's basically just a way of showing that nearly all of the ensemble members are on board with some decent snow now. It's a probabilistic way of looking at the likelihood of snow. The timeline for both charts is actually at the very bottom of each image with the further right you go on both charts moving further into the future of the model/ensemble run.

@MetVol

I have already asked one meteorologist this, and didn't get a solid answer. What is the difference on the SREF model between the Snow total Mean, and the Snow total Spread?

 

[MetVol]

@MetVol

I have already asked one meteorologist this, and didn't get a solid answer. What is the difference on the SREF model between the Snow total Mean, and the Snow total Spread?

Good question!

The mean is basically an average solution of the ensemble members. It's a "best guess" average solution based on the "wisdom of the crowd" of ensemble members.

The spread is a measure of certainty. It tells you how far apart the ensemble members are. Forecast certainty is inversely proportional to spread (the higher the spread, the lower the certainty/forecast confidence).

 

[hUTch2002]

Good question!

The mean is basically an average solution of the ensemble members. It's a "best guess" average solution based on the "wisdom of the crowd" of ensemble members.

The spread is a measure of certainty. It tells you how far apart the ensemble members are. Forecast certainty is inversely proportional to spread (the higher the spread, the lower the certainty/forecast confidence).

 

[norrislakevol]

Good question!

The mean is basically an average solution of the ensemble members. It's a "best guess" average solution based on the "wisdom of the crowd" of ensemble members.

The spread is a measure of certainty. It tells you how far apart the ensemble members are. Forecast certainty is inversely proportional to spread (the higher the spread, the lower the certainty/forecast confidence).

Ah ha!! Thank you for that info! Makes perfect sense.