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Winter Speculation 17/18 -December Thread


AMZ8990

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52 minutes ago, stadiumwave said:

 

No post :)

Will try to swing by later.   Nice set of teleconnections.  Weeks 3-7 are BN to sometimes seasonal.  The Control was snowy w 1' amounts over the mid state and east.  The mean, much more accurate as it compiles multiple runs and mutes extremes, had roughly 8-10" for NE TN and the northern Plateau.  Knoxville was 4+".  Sourthwest TN had 2"+.  Nashville was 4".  Jeff alluded to a thaw around Christmas.  For this run, the means just getting up to normal from BN.  I try not to hype, but that was a nice run which supports the runs before it.  I am wary after the January head fake last winter.  The GEFS is very cold in the medium range.  The EPS is as well, though to a lesser extent as it is always less extreme.  Lots of blocking up top.  I would suggest some cross polar flow.  Western ridge, eastern trough.  The pattern is modeled to flip during wk2 w a temp lag of about one week as cold fills the trough.

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18 hours ago, Carvers Gap said:

What is up, stranger?  Been missing your input.  Pattern looks good.  EPS still on board.  

Tennessee's current football woes have seen me spending a lot of free time on VolNation. But the pattern is looking better and better for the entire forum to be more active. At least for December.

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2 hours ago, John1122 said:

Tennessee's current football woes have seen me spending a lot of free time on VolNation. But the pattern is looking better and better for the entire forum to be more active. At least for December.

You u and me both!  I am on Rivals.   Man....... with this coaching search and upcoming weather pattern, I might not get anything done.

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Hey guys...about that time of year for winter hijinks! Let's hope we have more to follow this winter.

I did see Robert's post on FB last night where he talked about a big cool down coming right before Christmas...hope that works out! See the link below...

By the way, I know this isn't the banter thread, but I'm with you on this coach search...wearing me out!

WX South

 

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The cold continues to move forward in time on the models.  Will be by later to update.  Time for you all to come out of hibernation.  ETA is now up to day 6-7.  This would be a pretty big success for the models who potentially "saw" this week's in advance.  The 6z GFS/GEFS and 0z Euro/EPS (mean, and a crazy control run for cold) have cold, sometimes severe cold.  Fantasy storms on the GFS run for MS and Alabama at LR.

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Middle of next week, around Dec. 6, the mother of all (recent) cold fronts is due. Timing had been closer to Dec. 8 until yesterday. One Euro run sped up, then the next backed off. Yesterday ensembles were still closer to Dec. 8. Today, all operational and ensembles point to the faster Dec. 6.

A wave coming out of the Plains could still slow down the front. However faster and stronger themes add confidence, regardless of exact timing. Models keep a blocked up look to Day 15. Expect a couple milder or less cold days between fronts within the cold 8-15 day period. Mild 1-2 days between fronts is normal during a cold regime.

Switching to weeklies, BN may give way to a seasonable average Christmas week. CFS punted the SER that week in favor of BN temps. Euro weeklies has been near normal temps Christmas week for a couple runs. I still don't trust the weeklies past week 3, but they are cold.

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Looking like things are still on track for a major frontal passage on the 7th or so, gfs advertising enough moisture behind the front to bring the first widespread lower elevation snow showers to the region. Sometimes it over does that aspect of things though. The front spins up a low on the coast on the 12z run and actually gives steady snow to the far eastern mountains and western NC. That looks to be followed up by several clippers as the northern stream dominates. The GFS keeps advertising some form of large late storm, but that's another of it's biases. It usually spins up monsters in the day 14-16 time frame that basically stay there. The cold is coming though and I'll be surprised if we make it out without snow falling across the valley during December.

 

 

 

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How long has it been?  Fo-Eva................

It appears as if the cold is almost a lock.  Only questions are the depth and duration.   We usually see cold in waves in situations like are projected with a day or two warmup (maybe almost back to normal) before heading back below normal.  There does appear to be some energy flying around so as always it will be a delicate balance to see if we have any precip to play with and then figure out if it's going to be cold enough for that precip to provide something other than rain.

All in all, the pattern depicted is one we haven't seen in a while, and even longer for the month of December.  I think we are about to have to fire up the tracking bus.  Who is going to drive this thing?

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5 hours ago, tnweathernut said:

How long has it been?  Fo-Eva................

It appears as if the cold is almost a lock.  Only questions are the depth and duration.   We usually see cold in waves in situations like are projected with a day or two warmup (maybe almost back to normal) before heading back below normal.  There does appear to be some energy flying around so as always it will be a delicate balance to see if we have any precip to play with and then figure out if it's going to be cold enough for that precip to provide something other than rain.

All in all, the pattern depicted is one we haven't seen in a while, and even longer for the month of December.  I think we are about to have to fire up the tracking bus.  Who is going to drive this thing?

2qvw55s.gif

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3 hours ago, John1122 said:

00z kept hope alive and brings a snowy clipper through and begins building a blockbuster for the south by day 10/11.

 

sn10_acc.us_ov.png

 

It looks like it could get interesting from the 11th to about the 16th.  There are some major fantasy storms poppin up from run to run.  I'm definitely starting to get excited!!!

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49 minutes ago, AMZ8990 said:

It looks like it could get interesting from the 11th to about the 16th.  There are some major fantasy storms poppin up from run to run.  I'm definitely starting to get excited!!!

I am right there with you; looks like someone is going to cash in with some of these, just hope we can get some snow on the ground before we get the real cold temps!

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2016    9.34    6.77    3.16    0.64    2.37    3.86    6.25   10.07   10.48   12.83   14.16   15.09
2017   14.92   14.78   14.35   13.88    8.01   -3.18  -10.48  -14.42  -15.28  -16.79 -999.00 -999.00

 

QBO still dropping

 

SOI ROSE TO 30 + THE 28TH,almost a 30 point rise between the 26-28,then a drop of almost -15 points the 29th

 

gfs_T2m_us_50.png

 

 

 

ESRL   PSD   Daily Forecasts of Teleconnection Indices  from ESRL PSD Reforecast2 Project.png

 

gfs_T2m_us_50.png

 

ecmwf_z500a_wpac_9.png

 

 

We shall see,Asia shows a active period ahead of this time.Seems possible the GFS is on to something in the long range

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1 hour ago, John1122 said:

That's bone chilling stuff. I'm sure it will moderate but it's been forever since we've seen that in December. It does occasionally happen though, so it will need to be watched.

Very true.That's more Jan looks.But like you said though it can happen.12z already moderated

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2 hours ago, Carvers Gap said:

QBO has fallen to -17.20

It's allowing the -NAO to come to fruition I believe.  Not sure obviously on what the rest of winter brings, but days 4-16 look as wintry as almost any stretch we had the whole of last winter. Granted, in my area it was the warmest/least snowy winter in the last 70+ years.

 

Pivotal froze on the GFS at 138 but it had spit this out by late Friday night with snow still flying over approximately the Eastern half of the Valley from Northwest Alabama to SW Va. Snow depth through 138 shows that many of us will have white ground if nothing else if the clipper comes as advertised. Good timing as well since it arrives early evening into overnight.

 

 

 

prateptype_cat.us_ov.png

 

 

snku_acc.us_ov.png

 

snod.us_ov.png

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1 hour ago, John1122 said:

It's allowing the -NAO to come to fruition I believe.  Not sure obviously on what the rest of winter brings, but days 4-16 look as wintry as almost any stretch we had the whole of last winter. Granted, in my area it was the warmest/least snowy winter in the last 70+ years.

 

Pivotal froze on the GFS at 138 but it had spit this out by late Friday night with snow still flying over approximately the Eastern half of the Valley from Northwest Alabama to SW Va. Snow depth through 138 shows that many of us will have white ground if nothing else if the clipper comes as advertised. Good timing as well since it arrives early evening into overnight.

 

 

The 12z Euro was certainly interesting.  Looks like it tried to finesse a storm.  But it is trying to hunt.

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18z has an interesting situation setting up aside from the clipper system during the day Friday. This is associated with the coastal runner and presents more snow for NC than the previous 12z run, almost trickling into eastern portions of the TN valley but not quite. 

12z Run

gfs_mslp_pcpn_frzn_us_21.png

18z Run 

gfs_mslp_pcpn_frzn_us_20.png

A lot of time left for change, something to watch though. Could get interesting Friday afternoon though. 

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Looks like the longest stretch in two years of below normal temperatures coming up--starting Wednesday, and perhaps lasting for 2 weeks.  We certainly didn't have that last year, or the year before during the winter months.  And snow chances to go along with it is certainly a Christmas gift.

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Weeklies. BN from weeks 1-6.  Week 7 does depict a potential shift maybe to a full continent trough or at least a trough centered in the middle of the country with the potential to shift it all West...but AN heights over Greenland and eastern Canada during that time frame of week 7 battling a decaying PNA.  Long way out there.  I will place the temp map here without going into the clusters of weeks as Jeff calls them.  There is a bit of moderation.  The trough is centered a bit too far eat and does leave open the chance for AN heights to build in from the West at times.  Do I buy it?  For the short to mid range, I do.  LR is always a crap shoot.  The snow means range from 2.5" in Memphis, to 4" for Nashville, to 5.5" for Knoxville, to 3" for Chatt, and 10-12" for Bristol/Elizabethon/SW VA.  Northern MS and AL are at about 2".  What is even more interesting....that is with below normal precip forum wide.  Remember, if you are new to the forum...the Weeklies go out 46 days. So take with a certain grain of salt.  Just looking for the pattern.  The pattern is a strong +PNA w a weak to varying NAO through week 6ish.  Then, there is a hint that the cold backs westward OR we have a period of zonal flow.  How far? No way to know.  As a final note, the Northeast gets buried.  Watertown, NY, gets 40" as a mean...some of that is lake effect.  Boston is around 22" and Downeast Maine is 2'.  DC is 12".  NYC is around 15" in Central Park.  Just inland is much higher.  Why mention those?  Fairly big signal for storms on the East Coast and upslope snows in the mountains in addition to those storms.

IMG_1139.PNG

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