December Medium/Long Range Discussion

[Chris78]

11 minutes ago, NorthArlington101 said:

EURO also dials up several shots next week - doesn’t look boring. 
 

clippers on the 8th, 10th, and 11th. 

That clipper next Wednesday/Thursday is energetic.  That would be a solid hit.

[SnowenOutThere]

3 minutes ago, Chris78 said:

That clipper next Wednesday/Thursday is energetic.  That would be a solid hit.

[Eskimo Joe]

2 minutes ago, SnowenOutThere said:

YES

[WxUSAF]

This cool season so far, it seems we permanently have the D13-15 torch instead of our usual D13-15 blizzard.

[JenkinsJinkies]

Just now, WxUSAF said:

This cool season so far, it seems we permanently have the D13-15 torch instead of our usual D13-15 blizzard.

Like last year.

[SnowenOutThere]

Just now, Eskimo Joe said:

YES

Sounding from Cville is juiced with saturation past 400mb and well through the DGZ. Also has strong frontogenesis through the 850-700mb layer before LFC would take over above the inversion. Would be a fun evening!

[Heisy]

Yea as one person our Philly board said, there’s a -NAO there, but nothing is locking the 50/50 in place.

There’s been some OP runs here and there showing ways to score in this pattern. I wouldn’t expect a big dog or anything though.


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12z euro has a few N/S shortwaves that produce or come close to producing.


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[NorthArlington101]

EPS mean for Friday-Saturday is a paltry 0.5" or so across the region but that's better then the 0" it had at 06z. Gotta bring her back slowly

AIFS mean is 1-1.5" but it clearly does a terrible job of factoring out ice/mix, which does still seem to be in the cards for that time period, unfortunately. 

[Eskimo Joe]

Bottom line from the 12z long range is that we aren't losing this pattern for at least the next 7 to 10 days. We shouldn't see huge storms, but we can definitely score some snow before Christmas.

[Ji]

cansips looks decent for January. Has Feb with above normal precip

[SnowenOutThere]

9 minutes ago, NorthArlington101 said:

EPS mean for Friday-Saturday is a paltry 0.5" or so across the region but that's better then the 0" it had at 06z. Gotta bring her back slowly

AIFS mean is 1-1.5" but it clearly does a terrible job of factoring out ice/mix, which does still seem to be in the cards for that time period, unfortunately. 

Adding onto my post from last night but man this window is just a mess of energy out west. The first image taken at hour 60 on the latest Euro seemingly shows a simple setup as we have a nice bowling ball of energy out west and suppressed heights for it to follow east. Great! What could go wrong?

Ironically enough, the storm we are tracking isn't even this initial vorticity out west! As out of this seemingly simple setup we have two things that completely ruin this initial ball of vorticity's chances. 1. The press of vortex over southern central Canada prevents any real chance for it to meaningly amplify. 2. The weird lump of low pressure off the Mexican coast which stretches it out the other way. Additionally looking up to the 200mb wind the whole western US is in the exit region of the jet from the western US which just further suppresses cyclogenesis

So now what? Well by 24 hours later the energy out west has become completely shredded as it attempts to move east. 

Unfortunately, this isn't exactly conducive to a storm forming as we have the energy basically being squashed and pulled apart so piece one of energy fails completely at producing any storm. However, we now have shortwave 3 entering the picture diving into the high plains which interacts with the remaining mess of vorticity to spin up some actual precipitation. So by 24 hours later we arrive at this.

As we can shortwave one really just died out completely, but its leftover energy out west combined with shortwave 3 to create an extremely positively tilted axis (thanks to our friend shortwave 2). However, we manage to snag some precipitation thanks to the now favorable jet position over the southeastern US. Though the reason why it's ice is rooted in the initial problem; that being we have two different shortwaves! By hour 87 we are already under return flow at the low levels (through 850mb) by the first shortwave and we still have another day+ till precipitation even becomes a possibility!

Unfortunately, I don't think this setup really works out for us in its current form. What we can mainly hope for is a better oriented shortwave 3. Additionally, maybe a better positioned (further east?) shortwave 2 could transfer more energy into the system? Luckily, with such a complicated forecast synoptically it is quite possible this solution is far from the actual one which does give me a bit of hope. Either way I can't really say I'm too optimistic on this one. 

TDLR: I don't think its going to snow Friday-Saturday outside maybe an extremely light event, and even then we will probably have thermal problems. However, the forecast is so uncertain with 3 pieces of energy that it can't quite be completely dead as interactions out West could change. 

[bncho]

Just now, GaWx said:

On Nov 29th, the WCS daily PDO rose from ~-0.81 to -0.52, the fastest daily rise since Sept. 2nd:

FWIW PDO is almost positive now

[Ji]

3 minutes ago, bncho said:

FWIW PDO is almost positive now

paging the PDO Nazi @psuhoffman