Winter 2015-16

[Carvers Gap]

18z GFS suppresses the track of the 1.11 system.  Then the PV.  Wow.  Haven't looked past ten days yet.

[tnweathernut]

18z GFS suppresses the track of the 1.11 system.  Then the PV.  Wow.  Haven't looked past ten days yet.

You will like it when you do look beyond 10.  We finally have a modeled snowstorm for the TN Valley...........lol.  About two days ahead of when I thought we'd see one.

[Carvers Gap]

You will like it when you do look beyond 10. We finally have a modeled snowstorm for the TN Valley...........lol. About two days ahead of when I thought we'd see one.

We are gonna name it after you if it verifies. I know it is the 18z, but it looked primed at d10. Anyway, it is a long ways out. But I think it shows where the pattern "could" go...

[nrgjeff]

Euro operational has a messy double barrel for weekend system; lots of energy north no good. GFS is confused; 12Z a little north, 18Z buried south. Euro probably has it right with two pieces of energy in parallel streams. Even if the GFS is right 12Z is mostly cold chasing rain lower elevations; 18Z is too weak - boundary layer issues and/or downslope Valley. Euro would still get Kentucky and West Tenn. Plateau and Mountains would be it east. NWS offices are excited we have something to talk about in the discussion, but note their meh public forecasts.

 

Later on the extreme cold in the 18Z is probably an outlier. The 18Z Ensemble gets seasonable to slightly mild at the end of the run.

 

Euro weeklies just in break down the PNA pattern faster; in fact, they kill it first before the AO. American models had the PNA outlasting the AO/NAO a bit. Looks to me like an active 7-10 days and then milder in late January, no change in my thinking. This is my last post today. College Basketball time! February also offers hope for the late score...

[Carvers Gap]

You will like it when you do look beyond 10.  We finally have a modeled snowstorm for the TN Valley...........lol.  About two days ahead of when I thought we'd see one.

Frame the whole run...and cash in is my thinking.  Having energy rotate under that big Arctic air mass and into the SE.  Bout as perfect as a set-up as one could ask.  Also, and yes it is the 18z we are referencing so TIFWIW, it continues the cold through the end of its run. 

[Stovepipe]

I'm going to show my weenie off a bit in this post but hear me out.  I'm getting a little bit excited about the next few weeks and here's why.  As a busy person who can't be bothered to be all over every model run, not unlike many around here I'd imagine, it's nice to check in with Donald Sutherland and read his daily thoughts.  Since Hunger Games wrapped up he now has time to focus on weather and as Carvers said, he's money.  Fortunately he's optimistic, that's good.

 

But, the other lazy (weenie-ish) thing I like to do is check the Euro EPS snow meteograms daily.  Don't shoot me just yet heh.  Now I don't take any of those members as truth, hell when they show "snow" half the time it doesn't even mean snow p-type here.  BUT, if the EPS members start perking up, I start paying attention.  Then I'll get off my butt and start looking at the GEFS.  When I start seeing additional snow potential there I check the GGEM ensembles as well.  When these ensembles are in even somewhat decent agreement I start to dig into the real science, as best I can, of what the heck is going on.  A backward approach for sure, but I'm not a meteorologist, I'm just a busy guy that wants some snow in the Tennessee Valley and can't be bothered hang on every OP run.  This approach worked quite well the past 2 or 3 years (and weatherbell makes it easy to do).

 

Here's why I'm getting a little bit excited.  Somewhere around half of the EPS members are showing measurable frozen precip as I look at various locations around our region from west to east across the great valley.  There are some big dogs mixed in there in the later part of the period.  GEFS and GGEM members are also showing some of this potential.  Not the cotton candy barf we saw last year yet mind you but perking up for sure.  Then you look at teleconnections, climo, and trusted posters elaborating on the science of WTF is going on and BLAM, I'm a little bit pumped.  This is the south so I'd be a fool to get TOO excited, but clearly there is potential over the next couple or three weeks, if not well into February.

 

I'm going to keep watching these weenie snow meteograms and if they keep honking, I'm gonna keep honking and hopefully we can get something legit to track within a few more days.  SREF, HIRES NAM, RGEM TERRITORY OR BUST YO!

 

Sorry about showing my weenie off but I had to get that off my chest.  And no that is not a euphemism. 

 

[ShawnEastTN]

I'm going to show my weenie off a bit in this post but hear me out.  I'm getting a little bit excited about the next few weeks and here's why.  As a busy person who can't be bothered to be all over every model run, not unlike many around here I'd imagine, it's nice to check in with Donald Sutherland and read his daily thoughts.  Since Hunger Games wrapped up he now has time to focus on weather and as Carvers said, he's money.  Fortunately he's optimistic, that's good.

 

But, the other lazy (weenie-ish) thing I like to do is check the Euro EPS snow meteograms daily.  Don't shoot me just yet heh.  Now I don't take any of those members as truth, hell when they show "snow" half the time it doesn't even mean snow p-type here.  BUT, if the EPS members start perking up, I start paying attention.  Then I'll get off my butt and start looking at the GEFS.  When I start seeing additional snow potential there I check the GGEM ensembles as well.  When these ensembles are in even somewhat decent agreement I start to dig into the real science, as best I can, of what the heck is going on.  A backward approach for sure, but I'm not a meteorologist, I'm just a busy guy that wants some snow in the Tennessee Valley and can't be bothered hang on every OP run.  This approach worked quite well the past 2 or 3 years (and weatherbell makes it easy to do).

 

Here's why I'm getting a little bit excited.  Somewhere around half of the EPS members are showing measurable frozen precip as I look at various locations around our region from west to east across the great valley.  There are some big dogs mixed in there in the later part of the period.  GEFS and GGEM members are also showing some of this potential.  Not the cotton candy barf we saw last year yet mind you but perking up for sure.  Then you look at teleconnections, climo, and trusted posters elaborating on the science of WTF is going on and BLAM, I'm a little bit pumped.  This is the south so I'd be a fool to get TOO excited, but clearly there is potential over the next couple or three weeks, if not well into February.

 

I'm going to keep watching these weenie snow meteograms and if they keep honking, I'm gonna keep honking and hopefully we can get something legit to track within a few more days.  SREF, HIRES NAM, RGEM TERRITORY OR BUST YO!

 

Sorry about showing my weenie off but I had to get that off my chest.  And no that is not a euphemism. 

 

 

Hear Hear!!!

[1234snow]

I just peeked at the 18z GFS. Holy moly. If we don't score with that look then we never will. To me it looks as good as it gets. Keeps the ridge out west propped up the entire run. Like Carvers said the PV( or at least the tropospheric part of it) wants to park right over the middle of the country with southern waves rotating around it. It's like a snowy gyre!

[John1122]

Euro operational has a messy double barrel for weekend system; lots of energy north no good. GFS is confused; 12Z a little north, 18Z buried south. Euro probably has it right with two pieces of energy in parallel streams. Even if the GFS is right 12Z is mostly cold chasing rain lower elevations; 18Z is too weak - boundary layer issues and/or downslope Valley. Euro would still get Kentucky and West Tenn. Plateau and Mountains would be it east. NWS offices are excited we have something to talk about in the discussion, but note their meh public forecasts.

 

Later on the extreme cold in the 18Z is probably an outlier. The 18Z Ensemble gets seasonable to slightly mild at the end of the run.

 

Euro weeklies just in break down the PNA pattern faster; in fact, they kill it first before the AO. American models had the PNA outlasting the AO/NAO a bit. Looks to me like an active 7-10 days and then milder in late January, no change in my thinking. This is my last post today. College Basketball time! February also offers hope for the late score...

 

 

While this may very well happen, the past few years it seems like models either way are much faster to break down patterns than what actually comes to pass. We've seen it with warmth and we've seen it with cold. Models seem to try and be progressive and revert towards climo more quickly than the actual weather happens. 

[Daniel Boone]

Good point John on models adjusting to climo and pattern breakdown. Also, nino climo is programmed into some of these models as well. So , what would u expect really.?  BTW, picked up an inch of snow here today from a couple heavy snow showers in 20 minutes! No model forecasted the amounts observed. The Name/hires was just awful for this area per usual.

[Stovepipe]

MRX mentioning light snow area wide Sunday on the backside of the weekend rain system.  GGEM seems to support that, GFS and Euro not so much.

[tnweathernut]

MRX mentioning light snow area wide Sunday on the backside of the weekend rain system.  GGEM seems to support that, GFS and Euro not so much.

It wouldn't surprise me, especially for the elevated areas.  I could see the mountains rack up next week and even if they don't..........the snow guns will be at full capacity!

[Carvers Gap]

MRX mentioning light snow area wide Sunday on the backside of the weekend rain system.  GGEM seems to support that, GFS and Euro not so much.

0z UKMET would be a nice solution for late this weekend. 988 mb low sitting over the mid-Atlantic states.

[nrgjeff]

Time to punt the weekend system unless one is on the Plateau or in the Mountains. 5-7 days out the GFS and Euro perform better than the GEM and UK. Oh, but I like next work week. Yes, you read that right. Snow Skeptic Jeff is optimistic!

 

Pattern on all operational and ensemble models is beautiful! Upstairs the north and south branches of jet streams appear to work well; no major warm-ups for 5-7 days, and not suffocating super cold dry air. Proxy is the gorgeous thickness lines, mostly west to east. Don't get greedy for epic Miller A; just go nice and easy with west-east flow through the Deep South. GFS buries systems on the Gulf Coast, shocking I know; but one should come out farther north to our benefit, or at least weak WAA over a cold boundary layer. Euro is shaky but their parallel is farther south to our benefit. Delaying the chance until next week fits the history of cold taking a few weeks to fully establish. For the first time this winter I feel good about next week.

 

I still feel a little (snow weenie) pressure to get snow next week though, because I favor a return to milder the back third of January. Repeating: although the general rule is for blocking to outlast models, the Nino specific rule is for blocking to under achieve. Though El Nino is programmed into the models, those manual adjustments rarely fully correct the algorithm enough no matter what the adjustment for any pattern. Regardless of next work week I would still look for more opportunity in February.

 

I have to remind myself next week is not triple over-time in Lawrence, KS. I really want the win, but we also have February.

[Stovepipe]

The parallel Euro EPS (which apparently has been verifying more accurately than the regular Euro lately) has 42 out of 51 members snowing on Knoxville, mostly around the 13th and the 17th.  13 of those are over 2 inches and 3 are over 6 inches.  Memphis, Nashville, TRI all show similar potential around those dates.  It'll be interesting to see if the ensembles continue to be bullish for that time period.

[Carvers Gap]

12z GFS similar to the 18z from last night sends repeating shots of cold air down the back side ot the eastern trough for the duration of its run. Nice elongated trough. It would be nice to see the 10-20th time frame verify since many of us having been looking at it for some time. FWIW, I think this month is going to come out right around average give or take a few tenths of a degree. That is pretty good by January standards. I still think we see a trough in the East through February. Each winter we always see a "thaw." December was a torch, not a thaw. So, definitely a relaxation of the new pattern would be expected. Does it flip back to December? That was such a stable pattern...I doubt it. Just the fact that spring is approaching will make it tough for any pattern to lock in, cold or warm. But variablility is not a bad thing if you like winter storms. The teleconnections are still favorable through at least the first 2/3 of the month. If the pattern does relax, look for a potential storm there. As long as that polar vortex(es) remains at the higher latitudes, there is winter left to be had. Some years it just seems to drain down to the point that you know spring has arrived, meaning too long for winter to reload. I think this winter, we have plenty of opportunities through at least the end of Feb. March is always a crap shoot...so, who knows.

You know, it is January 5th. It is cold. It snowed off and on for much of the day yesterday. Many of us, including me, did not see winter arriving until mid-Jan at the earliest. Seems Mother Nature had different plans. However, there is one who did see its arrival coming earlier and that is John1122. He had some good ideas and backed them up with strong analog years. I have to admit, I am growing more convinced this not 97-98 all over again. Yes, December was an easy call for warmth. No model or index on the planet saw cold for Decemner in the SE. However, very few folks saw the early pattern flip that we are experiencing now until it was upon us.

As for the weekend storm, fewer options admittedly remain for the system to become the snow producer that some of us thought it might be. That said, many of us have spoken ad nauseum about the promise of that ten day period from the 10-20th. But....I will probably wait until Thursday evening to move on from that system. Models struggle when Arctic air makes a visit to the lower 48. We have seen some wild flips in the SE during recent years very close to the actual event(both good and bad flips). But the models IMO have not been solid since the teleconnections have switched. So, anything outside of three days deserves to be watched, especially systems suppressed our strung out to our south. The 0z UKMET can be a solid model, but it is on an island. Still, many of us predicted that by early Jan, we would have storms to track, though a flip of this sort was probably not envisioned by most. That is indeed now the case. Now time to see what the rest of the 12z suite can produce.

[Carvers Gap]

Also...I did get a weathebell sub. So, I do have access to better ensemble data and also the Euro weeklies. I am not sold on the fourth week of the weeklies. They are often a bit warm. Weeks 1-3 look about right. So, we will see. The GFS caught the current cold before the Euro did. Then it lost its way. Now, the Euro has taken back over as the pattern has become a bit more stable with the Eastern trough. But to me, the Euro has a warm bias in the extended and sometimes misses cold reloading. Who knows if that will be the case this time? A relaxation after cold is pretty normal. But is the GFS on to something with the trend since 18z last night of a colder long term?

[Carvers Gap]

Just a quick glance at the 12z gem and euro...noreaster possible Monday. How that impacts us? May be a bit late getting itself together(might not be bad either)...but nice storm to follow. Oddly, it appears the UKMET from this AM has company...from the Euro and GEM.

[Stovepipe]

The 12z GEFS members sure were fun to look at.  All but about 5 (out of 21) had 2+ inches of snow over large swaths of the valley through the 16 day period.  Lots of patches of 4+ inches in there too.  The mean was around 2 inches state wide.  Some members also found creative ways to squeeze out some snow from the upcoming weekend system.

[tnweathernut]

Nice disco in here today guys.  There appears to be plenty of potential next week, especially for Tennessee and the mountains.  I am looking forward to picking out a threat and tracking with you guys.  It wouldn't surprise me in the least to see a quick overrunning event sneak onto the models within 3 days.  

 

It took a while, but we finally have Jeff on board too.  

 

Buckle up, should be a fun 10 days.  If not..............we still have February, right? lol

[jaxjagman]

We'll be in Knox next weekend,son has a gymnastics meet at the Convention center.But we'll be staying in Maryville,wife is working that weekend as well.Euro was a tad colder this afternoon for Sunday.Believe mostly everyone will see snow.No big dog,just snow,better than nothing

[ShawnEastTN]

I feel pretty optimistic as well.  I'm just happy that the pattern seems to be getting in line for the opportunity for winter weather.  In and of itself for me is nice to see considering strong El Nino year.  I would love to get slammed with a major storm 93' style but I'm happy with anything to track even just an inch.

[Stovepipe]

We'll be in Knox next weekend,son has a gymnastics meet at the Convention center.But we'll be staying in Maryville,wife is working that weekend as well.Euro was a tad colder this afternoon for Sunday.Believe mostly everyone will see snow.No big dog,just snow,better than nothing

 

Let's try to meet up for a beer! 

[Carvers Gap]

Indeed, great discussion today both here and in banter. Jeff and the gang...great discussion. Great to have mets like Jeff and Bob that are willing to post on a board along with folks who do it as an interest/hobby.

[jaxjagman]

Let's try to meet up for a beer! 

Might be able to do that.

[jaxjagman]

Still looks like a rumble of thunder or two in some parts Sat.,Showalter is best down towards the S parts.Seems like the Nashville disco is going off the Euro this morning with post rain/sn showers that transition to flurries and ends late morning/early Sunday afternoon here in the Mid Valley.850's are drying out by that time.Best chance for accum should be towards the east like Jeff mentioned i believe yesterday.

 

DAY 4-8 CONVECTIVE OUTLOOK 
   NWS STORM PREDICTION CENTER NORMAN OK
   0233 AM CST WED JAN 06 2016

   VALID 091200Z - 141200Z

   ...DISCUSSION...
   SEVERE POTENTIAL SHOULD BE CONFINED TO PARTS OF THE SOUTHEAST IN
   ASSOCIATION WITH DEEPENING CYCLOGENESIS OCCURRING SOMEWHERE BETWEEN
   THE SOUTHEAST TO GREAT LAKES STATES ON SAT INTO EARLY SUN. THE POOR
   RUN-TO-RUN CONTINUITY REGARDING THIS AMPLIFICATION AND ASSOCIATED
   SPATIAL EXTENT OF MARITIME TROPICAL AIR INLAND RENDERS LOW
   PREDICTABILITY FOR ASSESSING A SEVERE THREAT. AS A COLD FRONT PUSHES
   OFF THE ATLANTIC COAST EARLY D5...SEVERE POTENTIAL SHOULD BECOME
   NEGLIGIBLE THROUGH THE REST OF THE PERIOD.

[jaxjagman]

The front coming through Monday  on the Euro is also showing more moisture with it in the Valley,not dry like it's been showing.If the Euro is right should at least see some flurries flying around,best accum spots would be towards the east again.We'll see if it keeps getting better.

[JayCee]

I noticed this morning that the AO (Arctic Oscillation) is about to tank.  Guess the PV is coming apart at the seams.  RIP. 

[Stovepipe]

I noticed this morning that the AO (Arctic Oscillation) is about to tank.  Guess the PV is coming apart at the seams.  RIP. 

 

 

Yep, check out Don Sutherland's post this morning.  Here is an excerpt:

 

 

Such extreme blocking would suggest troughing in eastern North America. More importantly, should such extreme blocking develop, it would provide a strong signal of a blocky February. In short, even as the most recent December proved to be an autumn, not winter month, an extreme AO-, should it develop, could offer the strongest signal so far that there will be plenty of opportunity for winter weather from mid-January onward. North America and Europe would both see such opportunities if past extreme January blocking cases are representative.

 

http://www.americanwx.com/bb/index.php/topic/47332-winter-2015-2016-medium-term-discussion/?p=3832891

[Carvers Gap]

Still looks like a rumble of thunder or two in some parts Sat.,Showalter is best down towards the S parts.Seems like the Nashville disco is going off the Euro this morning with post rain/sn showers that transition to flurries and ends late morning/early Sunday afternoon here in the Mid Valley.850's are drying out by that time.Best chance for accum should be towards the east like Jeff mentioned i believe yesterday.

 

DAY 4-8 CONVECTIVE OUTLOOK 

   NWS STORM PREDICTION CENTER NORMAN OK

   0233 AM CST WED JAN 06 2016

   VALID 091200Z - 141200Z

   ...DISCUSSION...

   SEVERE POTENTIAL SHOULD BE CONFINED TO PARTS OF THE SOUTHEAST IN

   ASSOCIATION WITH DEEPENING CYCLOGENESIS OCCURRING SOMEWHERE BETWEEN

   THE SOUTHEAST TO GREAT LAKES STATES ON SAT INTO EARLY SUN. THE POOR

   RUN-TO-RUN CONTINUITY REGARDING THIS AMPLIFICATION AND ASSOCIATED

   SPATIAL EXTENT OF MARITIME TROPICAL AIR INLAND RENDERS LOW

   PREDICTABILITY FOR ASSESSING A SEVERE THREAT. AS A COLD FRONT PUSHES

   OFF THE ATLANTIC COAST EARLY D5...SEVERE POTENTIAL SHOULD BECOME

   NEGLIGIBLE THROUGH THE REST OF THE PERIOD.

Jax.  The models are all over the place.  I won't even claim I have an idea of what is going to happen.  The 12z GFS has now changed the spacing.  One system rolls through the 10th - a double barrel look that many of the other models have hinted at for the past few days.  Then it spins up another storm around the 13th of the SE coast.  Has a 997 mb low off Cape Cod during that time.  The 0z UKMET puts a 996 mb low over sw KY on Jan 10th.  The Euro is pretty benign through d10.  Honestly, I think the bouncing around of the models just makes it about impossible to forecast past d3 if using models alone.  If the UKMET is true, definitely chances of some thunder Friday into Saturday...maybe not a severe threat.  But as you know, if it cuts significantly west, always a chance of a good line of storms to its south and east.  Right now, all of the models do point to some type of northwest flow event around Sunday...Several models over the past few days have tried to put a big storm on the EC next week.  I think any piece of energy beginning with this weekend's need to be watched.  It almost seems the models don't know which piece of energy to key on...Lots of pieces in play, but really fun to try to figure out.  The CPC teleconnections are screaming for a big winter storm in the East.

 

Holy cow...the AO!!!  Flirting w/ -6.