December 17th Clipper Discussion

[CoastalWx]

I'd rather one or the other s/w get out of the way.

[Tropopause_Fold]

I'd rather one of the other s/w get out of the way.

was thinking the same. 

[dendrite]

I'd rather one of the other s/w get out of the way.

But think of the prolonged wintry appeal.

[SnowMan]

I wouldn't throw that out yet..lol.

No I was asking cause I saw some mention that...lol

[CoastalWx]

But think of the prolonged wintry appeal.

 

NB.

[Tropopause_Fold]

the GFS at 5h is a mess with the energy coming down. in the end, SLP set-up is fine, but to really take advantage of the set-up, we'll want something a bit less messy.

[CT Rain]

But think of the prolonged wintry appeal.

 

So... we're looking at snow starting before dawn on Tuesday and not wrapping up until midday Wednesday?

 

A solid 24-36 hours of snow. Deep, deep winter!

[Tropopause_Fold]

Nam is Not really a worthless model lol.

Wouldnt be surprised if it handles this well.

i think elevations in CT and RI prob do well and im not sure of BL temps for bos metro tues pm, . I dont want to rely on "rates" to accumulate

it's not worthless. but honestly...it's really really bad on a run-to-run basis. 

[CT Rain]

the GFS at 5h is a mess with the energy coming down. in the end, SLP set-up is fine, but to really take advantage of the set-up, we'll want something a bit less messy.

 

GFS sort of worries me a bit with the second s/w so close behind. 

[Tropopause_Fold]

So... we're looking at snow starting before dawn on Tuesday and not wrapping up until midday Wednesday?

 

A solid 24-36 hours of snow. Deep, deep winter!

of course. probably 5-10. 

[SnowMan]

Surprised Blizz isnt all over this...unless he is hurt some ppl pointed out the dry slot last night...

[danstorm]

of course. probably 5-10. 

 

Let's be conservative, guys... 5-9 w/lollis to 12+

 

La la lock it up

[RUNNAWAYICEBERG]

still dont understand what the sw is doing and why its there, wouldnt all the energy try to dive in the backside of the clipper instead?

[weathafella]

GFS solution is meh. Kill one of the waves please.

[OceanStWx]

Regarding the NAM, I feel like such a tight s/w as modeled by the GFS almost warrants a NAM type model.

 

Just because it's run to run consistency is bad, doesn't mean I won't make some fancy graphics with it. In this case it's showing a very similar solution to the 18z GFS.

 

I left out frontogenesis and RH from these because it got too "busy", but I can say the fgen was all in the lower part of the mid levels (like 850 mb). And saturation was not an issue either.

 

So you have the omega in yellow (strong upward VVs above the strongest fgen). This intersects the DGZ nicely, and is located below a large region of low stability (shading is -EPV). In fact isentropes become very sloped for a time around 18z Tue.

 

18z GFS first, then 12z NAM

 

 

[ROOSTA]

This could be the storm that every member receives more snowfall than NE CT.

[Damage In Tolland]

Signal is there for some nice mesoscale bands Tuesday into tuesday night. This looks like it could be fun

[CoastalWx]

Yeah Chris, I was looking at the NAM BUFKIT and saw that -EPV layer or what is equivalent to this...folded back theta-e lines as well. This is the classic throw QPF out the window because it's instant fluff when the Atlantic moisture gets injected into this. Hopefully this comes in stronger.

[ROOSTA]

The QPF modeled for the Clipper is impressive. Nice little quick hitter for Eastern locales.

[moneypitmike]

Even NCEP puts a caveat emptor on using the NAM save for some specifics, and I agree as well.  I would also add convective initiation during the warm season (completely irrelevant now).

 

I think it was the ETA still back in 2005?   Not sure if that makes any difference, as I am less up in the know as to what changes have gone into the model over the last 7 years, but it nailed both the January event, then the one later in the year during December.  I don't recall it "nailing" substantially a better performance than the other guidance's since those two back when - but maybe I'm wrong.  

 

Bottom line, over the long haul it has a history of throwing errant solutions at one just when they are least prepared, gauging determinism with a helluva of a melon-baller.  I think though, it gets a passing grade for last night's gig.  Might have been dumb luck that it's NW bias played into a progressive situation with no blocking -- hell, maybe this is one of those particular patterns where it can find its way.

 

By the way folks, this is entirely a N-stream, dynamically charged system.  It really arrives with weak baroclinicity, which has been escaped seaward by last night's system. But because it has the torsional power of about 10 trillion megatons of tnt in those jet cores, it over-comes and puts out some winter tasties.   I would love to see this thing dig just 2 degrees latitude prior to hitting the longitude of ALB; that would probably be enough to bring a New Jersey model hammer.  Been while since a clipper performed as such.  

 

If that's what would give GC several inches instead of the 1-2 that's more likely, I'd love to see it, too. 

[OceanStWx]

Yeah Chris, I was looking at the NAM BUFKIT and saw that -EPV layer or what is equivalent to this...folded back theta-e lines as well. This is the classic throw QPF out the window because it's instant fluff when the Atlantic moisture gets injected into this. Hopefully this comes in stronger.

 

I think our forecast is on the conservative side for QPF right now (maybe a hair under the SREF). This kind of rapid development could definitely over-perform what we have going right now.

[moneypitmike]

I think our forecast is on the conservative side for QPF right now (maybe a hair under the SREF). This kind of rapid development could definitely over-perform what we have going right now.

 

Portions of your cwa could really do well with this.  Maybe I should move back to Bath.....

[OceanStWx]

Portions of your cwa could really do well with this.  Maybe I should move back to Bath.....

 

I would think Midcoast does all right. Latitude and longitude FTW.

[Damage In Tolland]

These fluff bombs are always fun..Look waht happened last week when we had .15-.20 qpf and places ended up with 3-5 inches,  This is same kind of airmass..maybe even a bit colder..influx some Atlantic moisture and things could really go to town away from the nasty Atlantic

[CoastalWx]

These fluff bombs are always fun..Look waht happened last week when we had .15-.20 qpf and places ended up with 3-5 inches,  This is same kind of airmass..maybe even a bit colder..influx some Atlantic moisture and things could really go to town away from the nasty Atlantic

 

Unless this goes over ORH..even areas further SE are game like the GFS has. This will be very cold aloft and surface inflow is not screaming from the east at 30kts.

[Clinch Leatherwood]

Meh....I think 1-3" here is a safe play what else is new.  Looks like a late night tonight until we get the dual s/w's resolved.  The GFS is doing what I talked about earlier and there's a chance it's right.  IE, maybe two lows.   I think it's about a 70% chance that's not going to happen...but you never know.

[Cold Miser]

Meh....I think 1-3" here is a safe play what else is new.  Looks like a late night tonight until we get the dual s/w's resolved.  The GFS is doing what I talked about earlier and there's a chance it's right.  IE, maybe two lows.   I think it's about a 70% chance that's not going to happen...but you never know.

Maybe, but considering there have been some nice little hits so far this December I'd say that even 1-3 deal out your way is a good thing.

[Max]

Is Kevin seriously trying to compare this upcoming systems airmass with the one that dumped 3 to 6 inches over the Wolcott, Southington, Meriden, CT corridor? Seriously Kevin, there is no comparison unless somehow 32F at the surface is the same as 25F at the surface. And the bigger difference is that we will be coming out low temperatures around 0F or even lower. That event we were low 30s before the event, during the event, and after the event. 

[Damage In Tolland]

Unless this goes over ORH..even areas further SE are game like the GFS has. This will be very cold aloft and surface inflow is not screaming from the east at 30kts.

Yeah just thinking back when there was one met saying he thought his area might be rain showers..

 

But agree this one looks nice to the coast

[Baroclinic Zone]

Meh....I think 1-3" here is a safe play what else is new.  Looks like a late night tonight until we get the dual s/w's resolved.  The GFS is doing what I talked about earlier and there's a chance it's right.  IE, maybe two lows.   I think it's about a 70% chance that's not going to happen...but you never know.

 

I like the subtle differences at 500mb between the 00z and 12z Euro runs.  Lead wave dampened out just a bit.  Also there is slightly better upstream ridging.

I'd still play my cards conservative as well.  1-3" with the caveat that if we can see the low develop just a hair earlier and S of LI we cash in.