CAPE

I still think the 26-28th window should present a chance for a coastal storm with cold established. 12z EPS strongly hinting, as have previous runs of the GEFS.

As long as we don't go dry. A bit of a split flow will help in a Nina.

Latest GEFSX continues the cold pattern into Jan.

Looking beyond next week there would appear to be another storm chance around the 27th on the GEFS. The cold should be entrenched at this point with increased chances for a more favorable track. Might be a bit too offshore if anything. Pretty nice h5 look.

Even if the EPS is more correct we can still get a good outcome. Would be a more convoluted setup, but the cold coming in looks legit. Worst case is we ridge and warm some out in front, get an inland track with rain, then cold and dry behind. That is always a default fail mode for us lol.

5 day mean ending on the 27th. Pretty decent given we have something trackable in that window.

The way things look we may get a good test next winter with a possible moderate CP based Nino, which typically has a favorable HL pattern and storm track with active STJ, but not very cold. Historically our bread and butter for above avg snow.

The biggest difference I see between the Euro and GFS ens in the upper level pattern evolution into next week is wrt the TPV that gets pinched off/displaced southward under the anticyclonic wave break as the EPO ridge amplifies and bridges with the upper ridge in the NAO space. GEFS involves that energy in 2 pieces(troughs) while the EPS dumps most of it in the 'trailing' trough that then digs further westward. For late next week, the GEFS ends up with this look, which implies coastal low development in a more favorable location- right along the coast or slightly offshore and further south. The EPS ends up with this look, which is more conducive for inland/north low pressure development.

There are always a range of possible outcomes for every pattern- some will be "good" even in those patterns that are less than ideal. This was the h5 pattern leading up to the big snowstorm for the lowlands of the MA early Jan last winter. Typical Nina Aleutian ridge, but displaced somewhat poleward, not the greatest trough position, with some SE ridge, and a transient/bootleg -NAO.

We have talked about that one a few times here. I was Living south of Westminster at that time. Only legit thundersnow I have experienced. Total whiteout, flash freeze with the heavy snow and sudden drop in temp. Rare event for sure. Only thing that came close for me was the Feb 2015 deal.

Are we still closing the blinds?

Love me some avocado. On/with anything, anytime.

Cold and dry behind it. Maybe a clipper incoming for NC. Hope someone doesn't engage in a meltdown.

Might not drop a lot of snow, but this would be fun AF.

That is one hellacious Arctic cold front on HH GFS.

Ji bought it.

If one particular poster didn't post, that other poster would not have had the chance to reply. Doesn't take much to get an avalanche started.

Hi!

The strongest indication for an event across guidance within our upcoming 'favorable window' is currently late next week into the weekend. As @Cobaltmentioned in his post, there is a pretty nice signal on the EPS. CMC ens holds the main trough and core of the cold back a bit, with some ridging out in front, and indicates a more messy looking scenario with initial low tracking NW. The timing is somewhat different. Weaker signal on the GEFS, but it is there, and it looks more like the EPS with a broader trough and initial colder air mass in place.

Having a -NAO does not always equal a block. A true sustained block in the atmosphere at h5 features a persistent dipole(upper low and high, ideally cutoff from the main flow). My more practical gauge is to see how lows(upper level vortices) behave as they progress eastward into the 50-50 region. If they essentially zoom through there and up into the NA, that's not a block imo. Not to say that situation isn't useful, but it is more indicative of a progressive flow and timing is critical.

The first chance of something trackable is early/mid next week as the trough digs underneath the sprawling Upper ridging across Canada. A wave off the Pacific takes the southern route underneath the PNA ridge. A lot of ways this could play out depending on the timing/location of the main features, but there is a path for a modest event. Here is the wave on the GEFS- The location/timing/orientation of the trough allows the wave to stay more intact on the GEFS depiction with a chance it can gain some latitude as the trough initially digs a bit more westward. Euro/EPS shears it out under the NS vortex. Beyond that it still looks something more significant may transpire around Christmas.

I was referring to ''stealing your thunder' lol. These snow maps are pretty useless at this range imo, thus the eye roll for ME posting it. That said, I like seeing the moisture focused more along the coast plus the advertised negative temp anomalies. It gives confidence that this will indeed be a colder period with the baroclinic boundary predominately to our SE, and waves taking a more favorable track. This idea has been pretty consistent on the ens means over recent runs.

^Snow mean for the period sort of matches. Like seeing more to the SE at this juncture. Yeah I know. Sorry WW!

Certainly doesn't give the indication of cutters during this period. Maybe not a big storm but it looks cold and there is some moisture.

Latest edition of the Euro Weeklies for the first week of Jan. Very similar to the GEFSX for the same period.