2016-2017 Great Tennessee Valley Winter Discussion

[bigdog660]

Whatever it does temperature wise, I just hope and pray we have an average to above average precip from now all the way through summer. Droughts of even little intensity are worse to me than even a snow-less winter.

[John1122]

After Thursday, the 00z run of the GFS was below normal all but one day of the next 12. Over those 12 days we get maybe .10 of precip. Super dry. 

At the very end of the run the ENS have a storm in the works, probably snowy on some members, not on others. 500 is good for cold still with over the top blocking growing stronger.

Canadian Ens builds a nice -NAO/-AO but we stay extremely warm while the cold sits in the west for what ever reason. The -NAO is even west based with rising heights over Maine up across all of Eastern Canada and Greenland. 

[Daniel Boone]

4 hours ago, Carvers Gap said:

We often use the word "torch" too liberally in the weather hobby community.  But w a +10.5 departure so far for Jan @ TRI....that is a torch.  And yet, 3+" of snow recorded at the airport.  Snow and overall temps for a given winter month do not always correlate.  We often gripe during cold patterns that we often don't score.  We had one chance at TRI this month and hit it.  And before folks climb out of the woodwork saying this was not seen...go back and look at everyone's posts.  It was well documented that it would be bad. 

It appears the dreaded 73-74 analog is working out well,unfortunately. Some difference of course as what snow there was  at this juncture then fell in December as opposed to January.

   February did feature somewhat colder weather then with minor snowfall amounts.

  Unfortunately ,for most of the area 73-74 was one of the top least snowiest on record. However, a slight shift in a couple storms tracks in February and it would have been decent. So, if a similar analog follow continues, there's still some hope for at least a little snow.

  On a sidenote , in case some dont know about it. Snowfall as well as Temperature averages have been "adjusted" to accommodate global warming. I personally disagree with it as it masks the climate changes.                                     Ktri average seasonal snowfall used to be 16" in the 80's, now it is 12" I believe. Pennington gap here in Lee county used to be 21". Now 16". 

 

 

[John1122]

06z GFS trends back towards a clipper effecting us next Monday. It had the clipper beyond 240 a while back and lost it, now it's showing up around Sunday night, with another stronger clipper 2 days later that verbatim misses us to the NE. Then another shows up a day and a half later and gets down to the KY/TN/VA border area. It's usually a 24 hour and in forecast with the exact timing/strength/track of these clippers. I'm just glad they're showing up again. I know our whole forum doesn't do well with them but the one that hits the area manages this, which is at least flakes flying for most of us.

[John1122]

GFS tops the run off with a long range fantasy event. Weird look at the surface and 500mb. Can't imagine it verifies but the GEFS had a system in the same time frame vs the bone dry OP run before this one. 

This run at the end featured a super vortex in the eastern GOA. A Rocky mountain ridge, a system from the north diving down to our west by a bit, spreading rain to snow north of I-40. It spits out 30 degrees and snow here with temps in the mid 50s near Chattanooga. 12 hours later it's snowing in North Carolina and light snow in most of East Tennessee and we're all in the 20s.

That Rocky Mountain ridge spits out this look by the end of the run. Way out in who knows land of course. But one of the positives about it is that after day 6 or 7 the west loses it's cold anomalies and is generally AN throughout the rest of the run.

[weathertree4u]

14 minutes ago, John1122 said:

GFS tops the run off with a long range fantasy event. Weird look at the surface and 500mb. Can't imagine it verifies but the GEFS had a system in the same time frame vs the bone dry OP run before this one. 

This run at the end featured a super vortex in the eastern GOA. A Rocky mountain ridge, a system from the north diving down to our west by a bit, spreading rain to snow north of I-40. It spits out 30 degrees and snow here with temps in the mid 50s near Chattanooga. 12 hours later it's snowing in North Carolina and light snow in most of East Tennessee and we're all in the 20s.

That Rocky Mountain ridge spits out this look by the end of the run. Way out in who knows land of course. But one of the positives about it is that after day 6 or 7 the west loses it's cold anomalies and is generally AN throughout the rest of the run.

I am just pleased that it should not be insanely warm for the foreseeable future. I can deal with no snow (not really but maybe if I say it enough it will make a difference) what I cant stand is stuff budding out in first part of February, which is where we were headed in the Middle TN area if we had had another week or two of 60's for highs and 40's for lows

[Carvers Gap]

4 hours ago, Daniel Boone said:

It appears the dreaded 73-74 analog is working out well,unfortunately. Some difference of course as what snow there was  at this juncture then fell in December as opposed to January.

   February did feature somewhat colder weather then with minor snowfall amounts.

  Unfortunately ,for most of the area 73-74 was one of the top least snowiest on record. However, a slight shift in a couple storms tracks in February and it would have been decent. So, if a similar analog follow continues, there's still some hope for at least a little snow.

  On a sidenote , in case some dont know about it. Snowfall as well as Temperature averages have been "adjusted" to accommodate global warming. I personally disagree with it as it masks the climate changes.                                     Ktri average seasonal snowfall used to be 16" in the 80's, now it is 12" I believe. Pennington gap here in Lee county used to be 21". Now 16". 

 

 

Prob too early to grab an analog for the season.  Was that a transition from weak Nina to neutral year?   If I was forced to choose one, it would 89-90' or 98-99'.  Cold in December followed by unrelenting warmth.  Now, if the upcoming cold holds....those two prob won't work.  I lived through some snowless winters in Knoxville...during the 90s.  Knox has received some snow this winter.  So the 90s analogs might not work.  I like the 90s analogs due to some Nino-like qualities showing during the past few weeks such as the rain in CA.  Coming out of last winter w a forecast strong Nina(did not verify), I felt this would be tough for snow.  I had some hope during the fall once the Nina was forecast to be weak.   I think the dagger is the Super Nino warming the NH so much that the latent heat is not gone.  Jeff and I discussed that in the Fall.  That and the QBO(might be some relationship there) are making it tough.  I wonder what the winters were like the following winters where a super Nino was followed by a weak Nina?  Or all of the winters followed by super NInos blended together?

[weathertree4u]

3 minutes ago, Carvers Gap said:

Prob too early to grab an analog for the season.  Was that a transition from weak Nina to neutral year?   If I was forced to choose one, it would 89-90' or 98-99'.  Cold in December followed by unrelenting warmth.  Now, if the upcoming cold holds....those two prob won't work.  I lived through some snowless winters in Knoxville...during the 90s.  Knox has received some snow this winter.  So the 90s analogs might not work.  I like the 90s analogs due to some Nino-like qualities showing during the past few weeks such as the rain in CA.  Coming out of last winter w a forecast strong Nina(did not verify), I felt this would be tough for snow.  I had some hope during the fall once the Nina was forecast to be weak.   I think the dagger is the Super Nino warming the NH so much that the latent heat is not gone.  Jeff and I discussed that in the Fall.  That and the QBO(might be some relationship there) are making it tough.  I wonder what the winters were like the following winters where a super Nino was followed by a weak Nina?  Or all of the winters followed by super NInos blended together?

That is exactly what I was thinking, what the Winters following similar Winters were like; course, I mean, if no one really saw this coming from the Fall, I think you had eluded to the fact that you might have, what or how can we have any hope of even guessing what next Winter will hold? Just seems like we should get into a better string of Winters here eventually. I mean if you look at the 50's, 60's and 70's and a few in the 80's, there were a few each decade that featured several big events.

[Carvers Gap]

45 minutes ago, weathertree4u said:

That is exactly what I was thinking, what the Winters following similar Winters were like; course, I mean, if no one really saw this coming from the Fall, I think you had eluded to the fact that you might have, what or how can we have any hope of even guessing what next Winter will hold? Just seems like we should get into a better string of Winters here eventually. I mean if you look at the 50's, 60's and 70's and a few in the 80's, there were a few each decade that featured several big events.

Seasonal forecasting,as I have noted many times, is a crapshoot.  My final thoughts for this winter were having a "normal" winter.  December looked good along those lines.  Jan is a torch.  Feb, not sure?  But there are advantages for those who attempt seasonal forecasting.  ESNSO climo will normally rule though there have been a few recent exceptions.  I though last winter that this winter would be bad...but the strong Nina never verified.  Once the weak Nina was forecast I was much more optimistic  as we have had some great winters w those.  Still, winter has five more weeks...one or two big storms and nobody remembers the long stretches without tracking.  So, the story is not written yet.  Next winter is showing some hints at a Nino(fickle to forecast strength this far out) state and the QBO should reverse to a negative state.  Also, we will not be coming off a super Nino the previous year.

Morning ensemble update.  John did a great job reviewing the GEFS and I have nothing to add there.  The EPS and GEPS hold the trough back far enough on this morning's runs to create a forced, weak SER and/or eastern ridge.  The operationals really want to move that ridge off the coast in a more progressive pattern...even the EPS control is more progressive.  If the PV does sneak south, things will perk-up in here.  Still, need to see a consistent driver before buying that.

[weathertree4u]

1 hour ago, Carvers Gap said:

Seasonal forecasting,as I have noted many times, is a crapshoot.  My final thoughts for this winter were having a "normal" winter.  December looked good along those lines.  Jan is a torch.  Feb, not sure?  But there are advantages for those who attempt seasonal forecasting.  ESNSO climo will normally rule though there have been a few recent exceptions.  I though last winter that this winter would be bad...but the strong Nina never verified.  Once the weak Nina was forecast I was much more optimistic  as we have had some great winters w those.  Still, winter has five more weeks...one or two big storms and nobody remembers the long stretches without tracking.  So, the story is not written yet.  Next winter is showing some hints at a Nino(fickle to forecast strength this far out) state and the QBO should reverse to a negative state.  Also, we will not be coming off a super Nino the previous year.

Morning ensemble update.  John did a great job reviewing the GEFS and I have nothing to add there.  The EPS and GEPS hold the trough back far enough on this morning's runs to create a forced, weak SER and/or eastern ridge.  The operationals really want to move that ridge off the coast in a more progressive pattern...even the EPS control is more progressive.  If the PV does sneak south, things will perk-up in here.  Still, need to see a consistent driver before buying that.

You always provide, along with a few others, detailed information in laymen's terms, which is appreciated. So the moral of the story is stay tuned I guess.

[Greyhound]

Didn't know exactly where to put this, but thought it could go here since we are experiencing a lull in weather activity (for now hopefully). 

MRX 2016 End of Year Climate Review:  http://www.weather.gov/mrx/end_of_year_climate_review

[tnweathernut]

I know many are trying to find a clipper that can drop far enough west for a general light snow in our region, but I really wouldn't dismiss the possibility of something bigger in the 6-10.  Pretty good look at an evolving (mostly cold) pattern on the 12z GFS.  Ridging out west looked good and northern stream energy danced around with the southern branch for a bit.  It could have been a much better run with some minor tweaks.

[Daniel Boone]

Carvers, 73-74 was a mod/strong nina but according to "Isotherm" global circulation patterns amongst other indices matched that one closest up to his mid. Jan update. Of course as we all know, there's never going top be a carbon copy.

    As far as from my record keeping that goes back to the early 70's, that analog has shown close similarities. Those 90's definitely were similar as well.

[Carvers Gap]

25 minutes ago, Daniel Boone said:

Carvers, 73-74 was a mod/strong nina but according to "Isotherm" global circulation patterns amongst other indices matched that one closest up to his mid. Jan update. Of course as we all know, there's never going top be a carbon copy.

    As far as from my record keeping that goes back to the early 70's, that analog has shown close similarities. Those 90's definitely were similar as well.

Thanks, DB.  Isotherm has been money w his seasonal forecasts the past few season.  

[tnweathernut]

3 hours ago, flash43 said:

Looking at days 6-10, I'm curious how much cold a super positive PNA can help yield given the neutral NAO/EPO. Looking 10+, if I'm interpreting early February teleconnection guidance correctly, it seems NAO/AO/PNA average around neutral to slightly positive. If the EPO can dig into more negative territory, you'd figure that's not far from a work-around setup.

 

Hey flash, thanks for posting in our forum...   Not much of a signal either way it appears to me after our PNA "burst", but I think we will see a more definitive bounce toward something (either good or bad) in the coming 3-4 days.  Not sure where we go in the future and from the looks of those indices, they don't give much help either.  Could be a lot of back and forth, and with cold air around it wouldn't surprise me to see something pop in the coming days.  Better than the 60's + we have been seeing for several weeks!

[John1122]

Heck, the LR GFS looks outstanding. Tall PNA ridge that's getting taller, low over the Aleutians and the polar vortex splits and a piece heads south of Hudson Bay all the way towards Northern Michigan. After Wednesday we only have one day above normal the rest of the way on the GEFS and cold is flowing straight from Alaska to the Southeast.

[Carvers Gap]

I did not think the 12z EPS looked all that bad.  It "seemed" to take another step towards the GEFS w suppressing the eastern ridge.  The PV is displaced a tick further SE.   The eastern ridge has gotten smaller w each run lately.  The control is again outstanding.  Hopefully these trends will hold.  Sure beats looking at 20+ departures.

[John1122]

GEFS has nice potential over the coming two weeks. A few have big miller A storms that bury us.

[BlunderStorm]

The GFS continues the current trend with slightly less snow in areas along and west of the Cumberland plateau. The lower valleys stay relatively the same with little change in the amount fallen. Finally the sheltered Mountain valleys and blue-ridge mountains have more snow projected at the 240 hour mark as opposed to the last run generally.

[John1122]

24 minutes ago, BlunderStorm said:

The GFS continues the current trend with slightly less snow in areas along and west of the Cumberland plateau. The lower valleys stay relatively the same with little change in the amount fallen. Finally the sheltered Mountain valleys and blue-ridge mountains have more snow projected at the 240 hour mark as opposed to the last run generally.

 

The exact path/amounts will be hard to pin down. I'm just happy that there's a decent chance of cold and snow flying in the region. Gotta take what you can get some years.  

[BlunderStorm]

1 minute ago, John1122 said:

The exact path/amounts will be hard to pin down. I'm just happy that there's a decent chance of cold and snow flying in the region. Gotta take what you can get some years.  

Oh, I understand I am more interested in the general direction the snow seems to hint at hitting. I'm sure just as soon as hopes go up they will tumble as usual haha. I'm not one for the warm weather we have been receiving lately but I certainly welcome the rain. Hopefully progress will steadily continue and the drought will be a distant memory especially for those south of us.

[Carvers Gap]

The Weeklies look pretty awesome.  Will discuss more later.

 

[weathertree4u]

59 minutes ago, Carvers Gap said:

The Weeklies look pretty awesome.  Will discuss more later.

 

Excellent 

[John1122]

Looking at the top 58 major east coast storms, many of which had significant impacts here, 36 of them occurred after today's date in winter. February and March are far more likely to produce major winter storms than November-January, though Knoxville's biggest snow event was in November. 

[AMZ8990]

1 minute ago, John1122 said:

Looking at the top 58 major east coast storms, many of which had significant impacts here, 36 of them occurred after today's date in winter. February and March are far more likely to produce major winter storms than November-January, though Knoxville's biggest snow event was in November. 

It was mid march of 2015 when we got our last 4+ Inch snowstorm here in west tennessee.  So I would agree with you on that.

[Carvers Gap]

Instead of going week by week...here are some general observations about the Euro Weeklies.  Seems to mesh very well w recent model trends. Gets cold late this week.  Ridge rolls through.  Cold returns...Trough returns as broad area o BN heights over NA.  Still some disconnect between 850 and 2m temps.  PNA ridge builds back in and holds throughout.  Great looking set-up.  Precip is AN to normal in E TN. Slightly BN precip western half of forum area. Interestingly, the axis of precip in the East is from northern Louisiana to coastal Maine.  Looks like plenty of qpf for the forum area even if slightly BN...i.e. if cold can hold, there is potential for winter wx.  IF, IF, IF...it is correct, it is a pretty strong signal that winter is not over in the East.  

MJO is iffy today.  American models want to circle back to winter phases.  The Euro wants to take the tour which would not be great for winter.  Several models go COD after phase 3...they hint they may try to sneak back across.  

Again, I am describing the Weeklies (added some MJO as bonus from Dacula Wx) as many don't have access.  Not sure if I am buying or selling at this point....but they look ten times better than looking at 60s for a couple of weeks.  

[John1122]

00z GFS really steps up the snow this run. It had been showing almost exactly these types of amounts from the northern stream between hour 240-384 a week or so ago before losing the waves for a few days. Now it's really finding the look again.  This falls over a 6 day period roughly. Rocking 8" in my area for that time frame. I'd love to see half that come to pass.

[jaxjagman]

Was going to post this in the severe thread but since this is the upcoming pattern possibly, i'll put it here.The Euro is showing the MJO getting into 4,5,6 coming up.Six is a blow torch in Feb.I was looking at the  #RRWT on the Organic forecasting site and they are also showing a big warm around mid month,this would fit in with upcoming MJO the Euro is showing.Also during this time we come into a wetter pattern when the MJO gets into 5,especially 6 & 7.So we should start to see a more active East Asia coming up shortly if all this falls in place.

[Daniel Boone]

The Euro Mjo may be right but, the way the models, including it have performed this winter in predicting Mjo cycle, I wouldn't take any stock in it at this juncture. As far as the wet pattern if it does come to fruition, better build an Ark around here then as it is very wet now. Over 16 inches of rainfall here since the end of November. 7.48" fell in December. 

[John1122]

06z kept a train of clippers/flow snow going again. This occurs over so many days, you'd probably see half of it on the ground at max but still much better than the balance of winter to date.