2016-2017 Great Tennessee Valley Winter Discussion

[Carvers Gap]

Look at that 1044 hp in the Plains.  That is a nasty set-up if that verifies on the para GFS.  The 0z GFS is rolling out slow tonight.  Looks like it is slower with precip onset and stronger compared to 18z with a feature in the Plains at 150.  The more it digs the more warm air gets pumped into the SE eliminating overrunning chances.  Now, the 0z GFS does look colder in the SE at LR that it's 18z run...looking well past the icing threat time frame.

[jaxjagman]

Think anything is on the table.The CMC kicks the SER out into the Atlantic.The GEFS,EURO,GFS not so much.But looking at the EPS it seems to be hinting at what the CMC is doing.I'd have to say the CMC is an outlier tho ugh at this point.

[John1122]

I've only been able to see the GFS out to 60. Any run with moisture coming, a frigid upper Midwest and a 1035 or higher HP around Iowa means winter weather for parts of the Valley.

[Carvers Gap]

Just now, John1122 said:

I've only been able to see the GFS out to 60. Any run with moisture coming, a frigid upper Midwest and a 1035 or higher HP around Iowa means winter weather for parts of the Valley.

It is updated on the NCEP site.  Not sure why it is so slow tonight.   Will be interested to hear your take.  Some close calls even on it with fronts stalling over the SE only to see cold rain ride the boundary where the CMC has frozen.  You catch the 0z UKMET?

[Carvers Gap]

Can only see through d9 on the 0z GFS but the SER(d5-10 timeframe...edit)is short lived compared to the 18z run through d10....looking at 2m temps.  It seems to be feeling that cold hp now.

[jaxjagman]

2 minutes ago, Carvers Gap said:

Can only see through d9 on the 0z GFS but the SER is short lived compared to the 18z run through d10....looking at 2m temps.  It seems to be feeling that cold hp now.

It's ran through tidbits now

[jaxjagman]

Well not all the plots but some

[Carvers Gap]

12 minutes ago, jaxjagman said:

Well not all the plots but some

Yeah, see it now.  I am out to d10 w WxBell that has the more specific GFS details.  The d5-10 timeframe appears colder at 2m w temps warming over TX at d10.(edit...TX cools by d10)  I guess my thoughts tonight would be that this cold air is creating issues with model solutions....lots of moving parts as well with weak waves riding frontal boundaries.  

[jaxjagman]

2 minutes ago, Carvers Gap said:

Yeah, see it now.  I am out to d10 w WxBell that has the more specific GFS details.  The d5-10 timeframe appears colder at 2m w temps warming over TX at d10.  I guess my thoughts tonight would be that this cold air is creating issues with model solutions....lots of moving parts as well with weak waves riding frontal boundaries.  

Agree,the Euro this afternoon was slightly colder also

[jaxjagman]

You want a white Christmas in the Valley,#fuggetaboutit

 

[John1122]

The Euro at day 10 is interesting with a weak LP in a good spot. Not sure on temps yet though.

[jaxjagman]

Nice line moving into Mid Tn mid day Sat by the euro.It looks cooler though than it

has been showing,dont see the VGP it's been showing.Still some -2 to -3 showalter for thunderstorms

[John1122]

I will also contend that once again, the GFS is way way way too warm at the surface for the features it's showing. 

Right now there's a 1032 high centered about 100 miles north of International Falls with another over Eastern Virginia. The temps are in the 10s and 20s everywhere in the upper Midwest except along the Canadian border areas and the Dakotas. My current temp is 21 degrees. 

 

At hour 216 the GFS has a 1043 high over Southern Wisconsin that drops into Central Illinois during the day still at 1040+. Temps are in the -15 to -20 range underneath it in Wisconsin that morning. 700/850/surface winds are N or NW here feeding down from that HP area. At 7am it's barely below freezing in a good portion of the area. The GFS depicts rain over the Southern half of East Tennessee with that 1041 HP sitting over central Illinois. I just find it hard to believe it wouldn't be colder here under those conditions.

 

In the same range the GFS has lost the idea of the -EPO HP. No Pacific cooperation, no Arctic cooperation and no Atlantic cooperation appear to be coming, at least on that run.

Of course 24 hours ago the GFS was living in a different world, massive HP in control in the GoA last night. Now a massive LP resides there at the exact same time. Not sure how a model can change so dramatically in 24 hours inside it's high resolution range for both runs. 

 

[jaxjagman]

Maybe it will change,but the SER seems like it's going to stick around

[Carvers Gap]

5 hours ago, jaxjagman said:

Maybe it will change,but the SER seems like it's going to stick around

The GEFS,GEM,and EPS basically lock a western trough/eastern ridge after d10...two straight runs, but have hinted at it before that.  All of that said, that -epo was locked into place for several runs prior to that.  What is shown on those three models is a pattern change, not just a passing warm 2-3 days.  Seems a bit early to flip, but maybe not.  Also seems when those ensembles lock into a warm pattern, they don't flip flop.  We have some things to track up to d10...so maybe we can strike before the iron gets hot.

[JayCee]

Just an observation, but in the winter of 84-85, we had a cold shot with accumulating snow in early December (in southeast KY), then the pattern did flip to crazy warm through Christmas with heavy rain and thunderstorms.  We even had some flooding around New Year's.  Temps were in the 50's-60's through much of the second half of December.  However, anyone living here in the 80's should remember how the rest of that winter turned out.  Not saying that's going to happen, but sometimes patterns switch back and forth before one locks in for awhile. It seems the models are having a terrible time trying to figure out the current pattern with massive flip-flops and changes from cold to warm. 

[Carvers Gap]

This does look like a pattern change in about 7-10 days.  What is the general rule for duration?  Seems like patterns hold for like 30-45 days.  But are the ensembles right?  The weeklies OTH had a warm spell centered on Christmas and then went back to winter.  As for analog years, 84-85 was an awesome year.  95-96 was a great snow winter, but didn't get going till after mid-Jan up here.  89 is the one that will always remind me of how winter can flip.  It was my first winter at UTK.  December was bone rattling cold.  January 1990 is a pivot point where I saw much of the 90s in Knoxville see little snow for long durations.  The following winters were pretty lousy until the spring of 93.  Jan/Feb 1990 were very warm to my recollection as I rarely wore a coat to class.  So, we will see what the ensembles do over the next few days after doing a different flavor every run for much of early last week.

[Daniel Boone]

30 minutes ago, Carvers Gap said:

This does look like a pattern change in about 7-10 days.  What is the general rule for duration?  Seems like patterns hold for like 30-45 days.  But are the ensembles right?  The weeklies OTH had a warm spell centered on Christmas and then went back to winter.  As for analog years, 84-85 was an awesome year.  95-96 was a great snow winter, but didn't get going till after mid-Jan up here.  89 is the one that will always remind me of how winter can flip.  It was my first winter at UTK.  December was bone rattling cold.  January 1990 is a pivot point where I saw much of the 90s in Knoxville see little snow for long durations.  The following winters were pretty lousy until the spring of 93.  Jan/Feb 1990 were very warm to my recollection as I rarely wore a coat to class.  So, we will see what the ensembles do over the next few days after doing a different flavor every run for much of early last week.

Carvers, You sure about 95-96 not getting going there till mid January ?? Here in Lee county our first widespread major measurable snow was December 10th with 7 " officially in Pennington gap at only 1377' elevation. The system traversed mississippi, ala., georgia and on to hatteras and ots. Roanoke got 10" from it. We picked up an inch christmas eve. January , we got the big one the 6th and 7th with 13 to 18" valleys and more than 2 feet above 2500 ft. Several minor to moderate events rest of month.  Feb., started out with a major storm with 10 " on the 4th and a record low of -21 the following day. rest of month no more major storms occurred mostly minor events. March had an 8 incher first day of spring.

[Carvers Gap]

26 minutes ago, Daniel Boone said:

Carvers, You sure about 95-96 not getting going there till mid January ?? Here in Lee county our first widespread major measurable snow was December 10th with 7 " officially in Pennington gap at only 1377' elevation. The system traversed mississippi, ala., georgia and on to hatteras and ots. Roanoke got 10" from it. We picked up an inch christmas eve. January , we got the big one the 6th and 7th with 13 to 18" valleys and more than 2 feet above 2500 ft. Several minor to moderate events rest of month.  Feb., started out with a major storm with 10 " on the 4th and a record low of -21 the following day. rest of month no more major storms occurred mostly minor events. March had an 8 incher first day of spring.

I was down in Knoxville at the time.  It was good there.  It was epic here.  I was speaking from the Knoxville perspective.   Could have been just a bit earlier than mid-Jan.  TRI was hit with two huge storms within about three weeks.  

[Daniel Boone]

Ok, thanks buddy. Figured something wasn't right, lol.

[Carvers Gap]

Here it is.  Was a week earlier than I remember.  Was followed in Feb by another big storm.  I "think" Knoxville may have finished AN for temps and snow...I will dig a bit this afternoon.  From the time I lived in Knoxville in 89 to when I moved to KPT in 98...this was second only to 93.  Keep in mind MRX has monkeyed with the snow numbers for that year.  In some cases, the numbers were missing last time I had checked.  Storm reports are the only reliable numbers I can get.  

http://www.weatherworksinc.com/20-year-anniversary-blizzard-of-96-1996

[Carvers Gap]

Here is one more link about the snow that winter.  The mid-Valley consistently got the shaft.  I kept calling home.  

My family told me they had like 20" in one storm.  Not so in Knoxville.

http://wate.com/2016/01/07/20-years-later-how-knoxville-dug-out-from-the-blizzard-of-january-1996/

[John1122]

That's the year of the most severely monkeyed records ever. I've got the KNS still from that storm and I'm 99.9 percent sure it snowed more than 5 inches in Knoxville. I know for sure that on February 2nd it snowed 20+ inches in North Knox. I was working there then. 

[Carvers Gap]

14 minutes ago, John1122 said:

That's the year of the most severely monkeyed records ever. I've got the KNS still from that storm and I'm 99.9 percent sure it snowed more than 5 inches in Knoxville. I know for sure that on February 2nd it snowed 20+ inches in North Knox. I was working there then. 

Edit...storm #1 I got around 6-8" with some ice at Papermill.  Could have been a bit more...(When I confronted MRX about the TRI data being wrong for that winter, they almost acted like it wasn't a big snow year.  I finally provided screenshots of NWS maps of the storm....then they said the records were lost.)Was a sharp cut-off for snow.  When I drove home a week or so later, I was shocked at how much metro missed.  

[JayCee]

What was the reason for MRX messing with the snow records?  And how on earth do records get "lost" in the age of computers?  Sounds screwy on their part. 

[Mrwolf1972]

Gfs-para 12z

[dwagner88]

1 hour ago, JayCee said:

What was the reason for MRX messing with the snow records?  And how on earth do records get "lost" in the age of computers?  Sounds screwy on their part. 

I don't understand this either. I know that I got about 4" of sleet and an inch of snow on top in the January storm. It is totally missing from KCHA records though. Best sledding I've ever done. Took forever to melt too. 

[Mrwolf1972]

[jaxjagman]

ZR and IP storm on the Para.Was in the NW getting hammered now the NE Valley on the 12z

[Carvers Gap]

Thanks for the maps and nice catch, mrwolf.  Jax, would be interesting to see the ZR numbers, but I am not aware of any place that has that output.  Where that situation sets up...I have no idea.  That overrunning situation has been on multiple models and multiple runs....but as rain.  It makes sense that some of it should be frozen.  The location is TBD.  Still a long way out there.  But when a big Arctic boundary sets up at that angle, there is always a chance waves run up and along a stalled frontal boundary draped across the south.