December 2019 Discussion

[MJO812]

Mjo is going to stall out in phase 2

[weatherwiz]

47 minutes ago, SophieG said:

southern Vermont? 

farther north I think...like central/northern VT. Not completely confident on it but I think there are some signals. 

[Henry's Weather]

December 14-16 has looked nice on ensembles for several runs, as PNA ridge acts in conjunction with polar shortwaves diving south to create a miller b threat.

[Hazey]

Don't mind a lull/warm up if we can get a re load before Christmas. Now that most everyone has seen measurable snow, the focus is on the holidays. Of course if we can get lucky between now and then, that will help pad the pack. 

[mreaves]

5 minutes ago, weatherwiz said:

farther north I think...like central/northern VT. Not completely confident on it but I think there are some signals. 

Just remember for all the SNE giddiness over the current storm (rightful giddiness, I may add) PF always gets his in the end.

[40/70 Benchmark]

33 minutes ago, ORH_wxman said:

I'd watch early next on the colder trend....I'm kind of with Tip on this one.

The PNA is actually spiking during this time with an EPO block already in place....this is going to want to negate the rising heights out ahead of the storm system. We even have a weak greenland ridge too. As Tip would say, the "correction vector" is colder.

 

Now that doesn't guarantee we don't cut...the individual shortwaves can overcome the background teleconnection....but it could turn into one of those flatter triple point deals where we maybe barely warm sector.

Watch for EPO to work in tendem with PNA to continue to deliver...potentially culminating in another biggie mid month with an NAO dip. We likely trend milder late month

[40/70 Benchmark]

10 minutes ago, Henry's Weather said:

December 14-16 has looked nice on ensembles for several runs, as PNA ridge acts in conjunction with polar shortwaves diving south to create a miller b threat.

I think that is next major threat...have liked that period bettwr than the current one

[mahk_webstah]

43 minutes ago, ORH_wxman said:

I'd watch early next on the colder trend....I'm kind of with Tip on this one.

The PNA is actually spiking during this time with an EPO block already in place....this is going to want to negate the rising heights out ahead of the storm system. We even have a weak greenland ridge too. As Tip would say, the "correction vector" is colder.

 

Now that doesn't guarantee we don't cut...the individual shortwaves can overcome the background teleconnection....but it could turn into one of those flatter triple point deals where we maybe barely warm sector.

Swfe 

[ORH_wxman]

5 minutes ago, mahk_webstah said:

Swfe 

Needs a lot of work to get to that point.....but still 6 days out.

[weathafella]

Friday seems to have lost some oomph in latest guidance 

[Typhoon Tip]

Just now, weathafella said:

Friday seems to have lost some oomph in latest guidance 

mm... it's a clipper with short wave-length governing mechanics moving through a fast hemisphere.   I.e., small and 'miss able'...so it may not be sampled - - as of 12z 00 hour it was situated 500+ miles out over the open east Pac in a horrendously fast flow.  Good luck

[Typhoon Tip]

12z GFS certainly likes the ides of the month... 

I mentioned this yesterday, our old saying up in my UML days ... "First it gets warm, then it gets cold, boom"  ... Seems that series of synoptic charts post D10 sets the table -

[powderfreak]

That 12z GFS was pretty fugly for Sun-Tue....two different rainers to Mainers.

Luckily it’s a long way out.  

[RUNNAWAYICEBERG]

11 minutes ago, weathafella said:

Friday seems to have lost some oomph in latest guidance 

Lost legs?

[CoastalWx]

1 hour ago, ORH_wxman said:

I'd watch early next on the colder trend....I'm kind of with Tip on this one.

The PNA is actually spiking during this time with an EPO block already in place....this is going to want to negate the rising heights out ahead of the storm system. We even have a weak greenland ridge too. As Tip would say, the "correction vector" is colder.

 

Now that doesn't guarantee we don't cut...the individual shortwaves can overcome the background teleconnection....but it could turn into one of those flatter triple point deals where we maybe barely warm sector.

I was thinking first one cuts and then cold oozes in for anything else. Maybe something  to follow up? Not a three day Rainer like some guidance has. But who knows, it’s early.

[weathafella]

4 minutes ago, RUNNAWAYICEBERG said:

Lost legs?

On crutches 

[Damage In Tolland]

Monday deal could turn into one of those ice deals in SNE

[weathafella]

Euro says toss the crutches and run!

[JC-CT]

1 minute ago, weathafella said:

Euro says toss the crutches and run!

I mean, it's 1-3 verbatim

[Sn0waddict]

1 hour ago, powderfreak said:

That 12z GFS was pretty fugly for Sun-Tue....two different rainers to Mainers.

Luckily it’s a long way out.  

Well at least it gives us a full fledged snowicane to make up for that at hr 300 lol

[weathafella]

7 minutes ago, JC-CT said:

I mean, it's 1-3 verbatim

Well it was prior run.  I still take 1-3...not jaded yet...wait till next month.

[Ginx snewx]

14 minutes ago, weathafella said:

Well it was prior run.  I still take 1-3...not jaded yet...wait till next month.

We clip

[RUNNAWAYICEBERG]

Boring times until mid month I suppose. Maybe an inch friday night to keep the weenie from drying out by then.

[MJO812]

3 minutes ago, RUNNAWAYICEBERG said:

Boring times until mid month I suppose. Maybe an inch friday night to keep the weenie from drying out by then.

Every model has the mid month threat. 

 

Let's do this

[mahk_webstah]

DC thread medium range is a good read

[Typhoon Tip]

Pretty cool image of the Missouri river cutting through the recent NP snow lay-down

https://weather.cod.edu/satrad/?parms=subregional-N_Plains-02-24-1-100-1&checked=map&colorbar=undefined

[40/70 Benchmark]

40 minutes ago, Snow88 said:

Every model has the mid month threat. 

 

Let's do this

Check this excerpt out from my 11/24 blog post....stratospheric assist mid Dec via NAO pulse imo

https://easternmassweather.blogspot.com/2019/11/wet-holiday-travel-week-leads-to-onset.html

The potential ramifications of this stratospheric warming on on the polar domain during the month of December may not be as many anticipate, and will instead act to ensure that blocking is not in fact sustained. While sustained episodes of blocking have been intermittently evident on extended range guidance, this is likely in error. Any such occurrence will likely be reserved for later in the season because conditions should be hostile for the development of sustained blocking during the first half of boreal winter 2019-2020 due to the considerable initial intensity of the PV, in conjunction with the delayed descent of the easterly QBO phase. As outlined in the winter outlook, this does not preclude intervals of negative NAO and bouts of wintery early season weather, owed to the elongation of the PV that is conducive to periodic and transient cold intrusions, as well expected volatility of the NAO modality. It is also important to note that while conditions appear favorable for at least minor disruptions to the PV,  as specified, its recovery from any such occurrence is expected to be both proficient and timely. This is due in part to climatology favoring only minor assaults early in the season, as well as the anticipated resiliency of a potent PV denoted by +AO conditions presently observed within the polar stratosphere.  Furthermore, while the period immediately preceding SSW events is usually hostile too blocking, it also can serve to amplify the MJO, which is currently projected to be in phase 8 at the height of the SSW, around December 15. 
 

 

-NAO Pulse Favored During Excited MJO Phase 8 in associated with Potential SSW Mid December

Thus it is reasonable to expect a major negative NAO pulse at mid month, which would coincide with a major coastal event prior to the abatement of said negative NAO, thereafter. This amplification of the MJO should constructively interfere with the apex of modest warm ENSO forcing to induce a prolonged period of +PNA and -EPO throughout the month of December, which will act to at least initially countermand the increasingly hostile polar domain in advance of any propagation of stratospheric warming near the pole. Thus the "thaw" period should be reserved for later in December and into January, as the warm ENSO forcing decays and Pacific realigns in advance of any impact of the SSW on the polar domain. The excited MJO will also be entering into milder phases at this time. The potential for more sustained high latitude blocking should then being to increase during the second half of January, approximately three weeks after the peak of any polar vortex disruption on or about December 15th.

 

Anticipated Sensible Impacts throughout New England During December

 

 

 

The month of December should be both active and variable. A robust PNA should ultimately be the primary driver of the pattern, thus central and northern New England should see the most robust snowfall anomalies. While the PV is likely to encounter some disruptions, it should recover, which may ultimately prove more inimical to the development of early season blocking, which is not climatologically favored, regardless. The erosion of the negative NAO/AO period should be offset by the development of +PNA and -EPO. The NAO should have some increased moduality, and a transient negative phase could link with the PNA to create a major early season storm. Favored period being from 12-5 to 12-19, however the later half of the period is more at greater risk due to Achambault potential in association with SSW induced negative NAO flex.

-1 to -2 departures north of Concord, NH, around normal down to 40N, and up to +1 points southward.

 

 

 

 

 

 

 

 

 

 

 

 

 

The deterioration of the +PNA/-EPO Pacific regime in conjunction with limited blocking may forebode any sustained thaw during the latter potion of the month and into the month of January, prior to any sensible impacts of downward propagation of mid December stratospheric warming later in January by way of increased blocking potential.

[mahk_webstah]

Ray the gefs and eps seem to support you.  Did you read mid Atlantic thread today?  Sounds like your blog.  

[RUNNAWAYICEBERG]

47 minutes ago, Snow88 said:

Every model has the mid month threat. 

 

Let's do this

Yea. Ray has been big on that timeframe since like October. 

[Torch Tiger]

the pattern looks cuttery through nearly x-mas