Winter 2011-2012 Kickoff Thread | December 2011

[bluewave]

This was the difference between the -EPO ridge last week and -EPO ridge Jan 1994. I understood DT was trying to make a point that you didn't need a +NAO to sustain cold air. But it was a shame he posted a map that didn't show what the AO region was like too. It looks like there was already block near the north pole, when the -EPO/+PNA set in:

That's how January 2004 worked out so cold with a block in a similar location.

[TheTrials]

That's how January 2004 worked out so cold with a block in a similar location.

the block over the davis strait is imperitive as well.

That looks like classic high latitude blocking with higher heights all over the place.

Great winter. Loved every second of it.

[bluewave]

the block over the davis strait is imperitive as well.

That looks like classic high latitude blocking with higher heights all over the place.

Great winter. Loved every second of it.

Plenty of ice on the back bays that January here.

[TheTrials]

Plenty of ice on the back bays that January here.

The worm will turn, we will still be above average this year.

[eduggs]

9/11 of the GEFS members from 12z show some kind of wintry threat between 12/16 and 12/18. All different types of threats (Miller A/B, clipper, anafrontal etc...) and all different timing. This could be a time frame during which a threat sneaks up on people because most of the operational models (esp the GFS) are delaying any potential threats to later in the month.

The 12z ECMWF has room for a threat Days 4-5. It looks a little like a few of the GEFS members that move a weak low off Hatteras with some light precip over the mid-Atlantic. If a little more of the SW Cutoff low slipped east or a separate shortwave caused a little digging of the midwestern trof, it's possible there could be some kind of east coast low. Anything that develops looks to ride along the strong temperature gradient. Hopefully we are on the cold side.

[BxEngine]

got down to 22º last night.

[TheTrials]

got down to 22º last night.

its what gives me hope. In the worst winters we struggled to see real cold or have temps dip down into the teens and low 20's.

There is a lot of cold air to the north, we just need to get it down here either with a poleward oriented -epo or real stratospheric warming that breaks up the ao from ice hell.

[Weathergun]

The setup on Euro ensembles for the threat around the 20th, favors the storm running up into the Ohio Valley or Central Apps, before turning right into New England:

[bluewave]

The setup on Euro ensembles for the threat around the 20th, favors the storm running up into the Ohio Valley or Central Apps, before turning right into New England:

The lack of blocking really hurts us in these patterns. There is no ridging to the north to help anchor

a Canadian hgh and cold air in place. Instead we get cutters with a strong return flow around

the Bermuda high.

[TheTrials]

status quo through xmas I am afraid. The globe is in a very stable pattern right now ,its not going to just snap out of it.

[Alpha5]

status quo through xmas I am afraid. The globe is in a very stable pattern right now ,its not going to just snap out of it.

the stratosphere simply is not warming enough to significantly alter the pattern.

I think we see less of a torch and more of a typical nina pattern though....cold->warm/rain->cold

[ag3]

12z gfs and 12z ggem both suggest some flakes around the day 5 period, from a clipper type system.

While not much, many would welcome it.

[TheTrials]

12z gfs and 12z ggem both suggest some flakes around the day 5 period, from a clipper type system.

While not much, many would welcome it.

Tough tough setup. I do think we may start to see a few balls bounce our way, even if its just that climo helps us come end of December into January. Any temporary blocking or even a split flow that kicks down the SE ridge for a little would be helpful.

[ag3]

Tough tough setup. I do think we may start to see a few balls bounce our way, even if its just that climo helps us come end of December into January. Any temporary blocking or even a split flow that kicks down the SE ridge for a little would be helpful.

Its from a dying clipper like system. Its possible in this pattern. But we're talking about a coating at best. Maybe more, if things line up better in upcoming runs.

[NYCSuburbs]

The current pattern's still pretty much terrible with no snow chances through the 10 day range, if not beyond, but at least the positive is that the pattern has slightly changed since November. The biggest positive is that we lost the raging positive EPO and the off-the-charts negative PNA, and the SE ridge isn't as strong/persistent as it was before with more frequent cool spells, unlike November where almost every ridge moving into the western US became a persistent large SE ridge. The stratosphere is still cold and the NAO/AO are still positive with blocking nowhere to be found, but there's still a few minor improvements. We're taking very slow steps, there's still a lot that needs to change and I wouldn't look for more than a few snow opportunities, if even that, through the end of the month, but eventually I think we'll get more cold and snow, possibly sometime into January, although nothing like the last 2 winters.

[dbc]

that would be pretty good, for nov 15th, lol.

I imagine you are joking but regardless those lows are actually spot on with the averages this time of year.

[TheTrials]

I imagine you are joking but those lows are actually spot on with the averages this time of year.

yes, I was.

[Alpha5]

GFS gets very close to a storm at 180....but its pushed OTS. I think we are finally seeing the evolution of this cutter-transitent cold-cutter pattern into a possibly favorable gradient pattern.

The mean trough axis by 150 is positioned further to the east than before so there is little room for storms to cut, especially with the PV bearing down on Quebec. Should make for an interesting scenario if we can time it right.

[ag3]

12z gefs mean still likes the idea of a coastal around the day 8 period.

The global models with higher resolution, drive this low in the lakes area.

The lower resolution of the gefs members, are probably skewing everything and keeping the shortwave weak and unable to amplify.

[eduggs]

Looks like we are headed to a regime featuring a parade of clippers. Maybe we can get some snow showers/squalls to whiten the ground. The GEFs include several members that redevelop the clipper around day 4 off the mid-Atlantic coast and move it offshore. Some have a few tenths QPF with that.

[eduggs]

Continued minor clipper threat for Sunday, with long shot at redevelopment or norlun scenario. Unfortunately the baroclinicity is very weak along the coast, so whatever weak vorticity that approaches cannot significantly amplify the trof. And the mid-level lows are weak or non-existent so there is minimal overrunning potential. But some of this could change so it's something to watch until a viable mid-range threat emerges.

[eduggs]

For the day 6/7 threat, we really need a s/w in the polar jet in Canada to phase or partially phase with the detached cutoff to pull down some colder air into the Plains around day 5/6. Otherwise, as soon as the jet shifts eastward and allows the cutoff to progress northeastward, mild mid-level air will flood the coastal plain.

[eduggs]

The cold air is locked up north of the polar jet while relatively milder Pacific air floods the US on the NW side of the cutoff.

[ag3]

Nam is on board with the gfs for a period of -sn on Sunday.

SIM returns have a decent period of flurries and -SN right on the NYC area.

[Guest Pamela]

Nam is on board with the gfs for a period of -sn on Sunday.

SIM returns have a decent period of flurries and -SN right on the NYC area.

.03 @ LGA and .04 @ KNYC (through hour 84)...so keep your eyes peeled or you might miss it,,,,

[ag3]

.03 @ LGA and .04 @ KNYC (through hour 84)...so keep your eyes peeled or you might miss it,,,,

Haha. I know.

SIMS though do show a decent area of precip over us at hour 84. Would probably be close to .10".

[Hailstorm]

We need to accumulate 3" of snow via the upcoming potential December 24-26 event or before January 1 hits; otherwise, we will enter the dreaded worst analog years for snowfall based on paltry December snowfall.

[CooL]

we should talk about potential events in this thread.

Dec 2010 snowcover

Dec 2011:

[TheTrials]

While generally I think these types of posts are better kept to a banter thread because they are so far out, its good to keep the serious threads a foot. I really like what I have seen the past few days being modeled in the long range on the other side of the globe as we are seeing heights rising which is helping push the PV south and east which is helping us cool down over the east Also, looks like we see some real ridging out west, not off the coast. I am excited about the 25-28th time frame. Here it is on the euro ensembles

Also notE the ridging over the top of greenland, its by no means a -NAO, but it may help to keep the cold air anchored in and slow down the pattern just a little

[H2Otown_WX]

18z GFS with nothing of note verbatim for most of the run..until it tries to go 12/30/2000 on us.