December and January Pattern Discussion

[jaxjagman]

Interesting that the Euro and CMC show some blocking in the Atlantic vs the GFS....... which appears to split the vortex and send a piece of it northeast instead of sending the trough fully down into the east.  Maybe the Euro has the right idea for next week?

Hopefully the GFS is wrong like you said,i'd hate for that piece to get sucked back into the PV again,but the strat is warming so likely hood of that is slim i'd think.

[tnweathernut]

anyone else holding their breath that the Euro is onto something?  Or just me?  If it's not going to happen, I'd like to see the Euro go ahead and jump the train off the tracks.  As consistent as it has been in showing a storm over the last few days with a very cold airmass coming into it, the GFS has been equally steady in showing light overrunning and the big HIGH a day+ later in trying to come in....

[jaxjagman]

EXTENDED FORECAST DISCUSSION

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1058 AM EST TUE DEC 31 2013

VALID 12Z FRI JAN 03 2014 - 12Z TUE JAN 07 2014

A VERY WINTRY SCENARIO IN THE EAST STARTS OFF THE MEDIUM RANGE

FORECAST WITH A QUICK WARM UP IN THE CENTER OF THE COUNTRY. THE

WARM UP IS SHORT LIVED AS A NEW AND SIGNIFICANT OUTBREAK OF COLDER

AIR BEGINS TO ENTER THE NORTHERN ROCKIES AND PLAINS BY DAY

4/SATURDAY AND PROGRESSES EASTWARD BY SUNDAY DAY 5. WITH LARGE

UNCERTAIN IT STILL APPEARS THAT SOME FORM OF PRECIPITATION EVENT

WILL FORM IN ASSOCIATION WITH THIS NEXT OUTBREAK OF COLD AIR ON

DAY 5 INTO DAY 6/MONDAY...WITH A HUGE RANGE OF SOLUTIONS FROM A

FRONTAL PASSAGE TO A MAJOR CYCLONE. BY DAY 7/TUESDAY...MUCH OF

THE CENTRAL AND EASTERN US IS UNDER THE INFLUENCE OF BELOW TO MUCH

BELOW NORMAL TEMPERATURES.

A CUTOFF UPPER RIDGE OVER GREENLAND/NORTHEAST CANADA WILL HELP

RETAIN AN UPPER LOW OVER SOUTHEASTERN CANADA THAT CONTINUES TO

FORCE A TROUGH MOVING TOWARD THE EASTERN US TO REMAIN ON A PATH

CONDUCIVE TO SNOW OVER PORTIONS OF THE NORTHEAST US ON DAY 3.

WHILE THE DETAILS OF THE TROUGH EVOLUTION SEEM FAIRLY

STRAIGHTFORWARD DURING THE BEGINNING OF THE MEDIUM RANGE PERIOD

FOR THE ENSEMBLE MEANS AND THE EVOLUTION OF A COLD CANADIAN HIGH

BUILDING EASTWARD ACROSS SOUTHEASTERN CANADA ARE ALSO

STRAIGHTFORWARD...THE DETAILS OF THE ACTUAL TROUGH EVOLUTION AND

RESULTING SURFACE BAROCLINIC STRUCTURE REMAINS COMPLEX.

SIGNIFICANT MODEL SPREAD DUE TO THE LIKELIHOOD OF SEVERAL CENTERS

OF LOW PRESSURE OF VARYING STRENGTH COMING TOGETHER TO EVENTUALLY

FORM A CYCLONE OVER THE WESTERN ATLANTIC CONTINUES TO MAKE THIS A

CHALLENGING FORECAST EVEN AT THE START OF THE MEDIUM RANGE. IN

GENERAL...CONTINUITY FROM THE OVERNIGHT FORECAST IS MAINTAINED

BASED ON THE CONSISTENCY OF THE ECMWF ENSEMBLE MEANS WITH INPUT

FROM THE 00Z ECMWF AND 06Z GFS...BOTH OF WHICH MAINTAIN A SIMILAR

SPEED AND AMPLITUDE OF THE TROUGH NEARING THE EAST COAST. WITH THE

MAIN TROUGH NEARING THE EAST COAST BY FRIDAY MORNING...A MULTIPLE

CENTER SURFACE SYSTEM IS STILL EXPECTED WITH THE REMAINING

QUESTION BEING HOW INTENSE THE WESTERNMOST SURFACE LOW RESPONDS TO

THE UPPER LEVEL TROUGH WHILE OTHER SURFACE CENTER OR CENTERS SCOOT

FARTHER EASTWARD. IN ANY EVENT...WHATEVER SNOW IS FALLING ON

FRIDAY MORNING SHOULD BE MOVING EASTWARD OUT TO SEA DURING THE DAY

AS THE SYSTEM CONTINUES EASTWARD.

WITH A MEAN UPPER RIDGE TRENDING TO BUILD OVER THE EASTERN PACIFIC

FROM THE SHORT RANGE INTO THE MEDIUM RANGE...SEVERAL SHORTWAVE

SYSTEMS WILL BEGIN TO PROGRESS SOUTH AND EASTWARD OVER WESTERN

CANADA WHILE ANOTHER LARGE UPPER LOW OVER NW CANADA ALSO BEGINS TO

MOVE SOUTH AND EASTWARD AS WELL. BY DAY 5...ANOTHER LARGE VORTEX

WILL BE FOUND ACROSS SOUTH CENTRAL CANADA WITH A HUGE MASS OF

ARCTIC AIR POISED TO MOVE SOUTH AND EASTWARD ACROSS MUCH OF THE

CENTRAL AND EASTERN US. SIGNIFICANT DIFFERENCES ALSO CHARACTERIZE

THIS DEVELOPMENT WITH THE ECMWF ENSEMBLE MEANS SHOWING THE LARGEST

AMPLITUDE AND GREATER SOUTHWARD PUSH OF THE ARCTIC AIR WITH

GFS/NAEFS ENSEMBLE MEANS SHOWING A SLIGHTLY FLATTER

SCENARIO...ESPECIALLY BY DAY 6. WHILE THE 00Z ECMWF CREATES A

POTENTIALLY HISTORIC SCENARIO BY DAY 6...IT REMAINS A VERY LOW

PROBABILITY SOLUTION AS IT REMAINS MUCH MORE AMPLIFIED THAN THE

CORRESPONDING ECMWF ENSEMBLE MEAN SOLUTION. THE 06Z GFS ACTUALLY

LOOKS MORE LIKE THE 00Z ECMWF ENSEMBLE MEAN SOLUTION AND IS

SOMEWHAT FOLLOWED WHILE STILL SHOWING A VERY LARGE COLD OUTBREAK

MOVING INTO THE CENTRAL AND EASTERN US ON DAYS 6 INTO 7...WITH THE

DETAILS OF HOW LOW PRESSURE AT THE SURFACE ULTIMATELY DEVELOPING

ALONG THE LEADING EDGE OF THE COLD AIR STILL VERY MUCH UNCERTAIN

AT THIS POINT WITH A VERY MODEST SYSTEM SHOWN AT THE PRESENT TIME

BUT WILL LIKELY CHANGE SIGNIFICANTLY AS THE DAYS GET CLOSER.

CHANCES ARE THAT THIS NEXT SYSTEM WILL LIKELY ALSO BE A

SIGNIFICANT WINTER WEATHER EVENT SOMEWHERE FROM THE TENNESSEE AND

OHIO VALLEYS EASTWARD INTO THE NORTHEAST.

KOCIN

[lugnuts]

anyone else holding their breath that the Euro is onto something?  Or just me?  If it's not going to happen, I'd like to see the Euro go ahead and jump the train off the tracks.  As consistent as it has been in showing a storm over the last few days with a very cold airmass coming into it, the GFS has been equally steady in showing light overrunning and the big HIGH a day+ later in trying to come in....

To be honest i want look at the models right now...I know i will jink's the Euro..Lol...Just hoping in a few day's when reading the forum I see a Thread that start's with "The Great Blizzard of 2014"..

[Carvers Gap]

Jaxjagman, great read that you posted. I am assuming THE Paul Kocin wrote that. That article really sums up the scenarios and difficulties with the arctic boundary.

[codgator]

If the Euro hits it hard again I'm all in for a Tenn special!

[Carvers Gap]

12zGFS appears to develop the slp on the initial frontal passage where JB mentioned(earlier today via Twitter) that it may very well develop along the arctic boundary. I know just enough to be dangerous there. What do you all say?

[jmundie]

UKIE has a pretty good track, but doesn't bomb out quite like the euro

 

 

[1234snow]

12z CMC is all aboard and is even colder than last nights run and brings the PV a little further south as well.

Hour 162:

Hour 174:

Sent from my iPhone using Tapatalk

[tnweathernut]

Not feeling good about the UKMET or Canadian (for snow). For cold, all systems appear set at GO.

Sent from my iPhone using Tapatalk

[John1122]

Canadian at 192.

 

[John1122]

Canadian with the weak reflection in the GoM and a powerful storm cyclone in the Lakes.

 

[John1122]

Without the deep snowcover of the Euro, the Canadian is "warmer" with it's -5 to -10 temps. A 1050mb high is massive this far south. It's pretty huge in the Northern Plains.

[tnweathernut]

Just looking at 500, out to 96 on the 12z Euro seems to depict a storm that will be a bit further north and west of earlier runs with the storm.  Let's see how I do at extrapolating.

[Carvers Gap]

Euro shows a massive cyclone off the NE coast at 72

[tnweathernut]

As I expected, the Euro is a bit further north and west (center developing in western Arkansas) at 120.  Let's see where it goes.

[Carvers Gap]

As I expected, the Euro is a bit further north and west (center developing in western Arkansas) at 120.  Let's see where it goes.

You know the Canadian showed a similar solution. Wonder if the cold front dragging through the GOM might not trigger a slp. Hinted at a wave on the Canadian.

[tnweathernut]

You know the Canadian showed a similar solution. Wonder if the cold front dragging through the GOM might not trigger a slp. Hinted at a wave on the Canadian.

I'd rather have the initial wave develop further south.  I think if one blows up, that's the most likely candidate.  What is going to stink is the fact I won't have maps to cover the critical time period b/w 120 and 144, though it may not matter as it looks too far north and west initially with the low in western Arkansas

[Carvers Gap]

I'd rather have the initial wave develop further south.  I think if one blows up, that's the most likely candidate.  What is going to stink is the fact I won't have maps to cover the critical time period b/w 120 and 144, though it may not matter as it looks too far north and west initially with the low in western Arkansas

That low looks like it will cut west of the Apps and slide towards the lakes...the trailing frontal boundary is what I am interested in. Definitely a new wrinkle.

[Mr Bob]

This is not the run that snow lovers were looking for though it is certainly not unexpected in this time frame....much more reasonable on the upcoming cold....

[tnweathernut]

Full latitude troughs will usually crush anything in its path.  If that occurs, the next likely opportunity would be right when the pattern relaxes. (late next week maybe) JMO

[tnweathernut]

The biggest differences I can see in this run vs 0z (aside from everything being shifted further west by about 150+ miles) is that it doesn't deepen it as rapidly vs. the prior run.  It still gets to sub 955, but it does it much further north in latitude, which means the bulk of the cold is not as readily pulled down as far as 0z did. 

[Carvers Gap]

It is less extreme, but still looking to discharge some very cold air. I have a hard time believing that active southern stream will stay suppressed very long. Seems to me that a solution is still not at hand. Definitely a more realistic portrayal of the slp with no blocking in place.

[tnweathernut]

Earlier runs seemed to press the arctic air further south and east sooner.  This run looks "GFS like" in the speed of the colder air

[tnweathernut]

By 192 the 850s REALLY begin to relax, I wonder what the ensembles will say. Looks almost as quick an exit as the coming cold for the 2nd/3rd.  Maybe that is right.  It doesn't really have any sustained Atlantic blocking.

[jmundie]

To me - the lynch pin on this whole thing is the Thursday system. The euro was consolidated with the first system, which pushes just enough ridging into Greenland to keep our Sunday storm from cutting too far west of the apps.

 

12z euro moves toward the gfs with the double barrel system thurs/Friday which doesn't give us any help in Greenland, which leads to lakes cutter.

 

Unfortunately, it looks like that's going to be the scenario we're dealing with.

[Carvers Gap]

I will still take below normal temps and a wet pattern any day of the week.  This may be one of those winters where we don't nickel and dime our way to average - may just be one big storm.  May just be a juicy system falls out of sync w/ the current pattern and connects w/ an intrusion of cold air.  Probably going to need the normal shake-up that does occur as temps warm every so slightly towards late January. 

[franklin NCwx]

We need something to in the southern stream. Both storms we are following are northern stream pieces of energy. This is why we do best in Nino years.

[Carvers Gap]

To me - the lynch pin on this whole thing is the Thursday system. The euro was consolidated with the first system, which pushes just enough ridging into Greenland to keep our Sunday storm from cutting too far west of the apps.

 

12z euro moves toward the gfs with the double barrel system thurs/Friday which doesn't give us any help in Greenland, which leads to lakes cutter.

 

Unfortunately, it looks like that's going to be the scenario we're dealing with.

 

Yes. I do think that is good analysis of what is happening.  The strong the system is Thurs/Fri, the more it impacts the Jan 6 system.  If that low is a cutter(and it cuts far enough west), it will be interesting if the cold front drags its feet.  If it does, slp/wave could form in the GOM.  The Canadian hinted at it.  The Euro showed nothing.  While I think that 1985 cold is probably not realistic and probably never has been, I don't think the system next week is being modeled well.  Now, that doesn't mean it is going to snow in the SE.  I think the models are all over the place right now and this solution could just be one of many...as yesterday's were.

[tnweathernut]

We have to keep in mind the system for the 2nd and the changes it has undergone from day 7 till now (and it's still not set in stone).  Changes are the rule of the day on modeling currently