12Z Model Thread 12/22

[dtk]

dtk et al, any idea why the PVA on the GGEM is so difuse?

First, I don't want to expand too much, but my citing of PVA wasn't meant to imply that this is what to always look for and/or is causing the surface reflection to be where it is. I was just saying at first (quick) glance things seem to be consistent given what the mid/upper levels looked like.

I honestly haven't looked much at the GGEM (other than the few plots posted on this forum)....so I'll defer to others if they want to attempt to explain the difference in the evolution (and why the trough doesn't seem to really want to go negatively tilted).

[SteveB]

Where's SteveB now? *cue DT*

As others have said, northern stream energy was much more pronounced and dug out the trough instead of it washing out as was the case (and ridiculous) on the 0z/6z GFS. Pretty encouraging run.

BIG change, plenty of time. Right where we want it (I think). I cant help but recall the 12/19/10 storm that we all thought would pull closer to the coast when progged just barely out of range for a hit hit though. Hopefully we can buck the La Nina climatology and this beast develops it's own!

Looking good for now guys!

[A-L-E-X]

Haven't seen the NAO forecast, but many of the big ones over the years have occurred when the NAO was increasing (which includes decreasing negativity).

Yes, and this was definitely the case with PD2. We want a changeable NAO not a strong signal either way-- as you'll note some of our best winters (like 1960-61) featured an avg nao signal near 0, which indicates volatility. 2002-03 featured a slightly positive nao and 1993-94 was actually quite positive.

[SteveB]

at 108n hrs look at the 500 mb map

then the surface

IMO the Low is still waaaaaaaaay too far east given that the 500 Low closed and negative SHOULD be capturing it and pulling it back

I agree with this and is why I'm more optimistic for THIS event than the last. Synoptic pattern says it all.

[rainstorm]

It also says 1064 H right next to it too

that would be a very impressive pressure gradient.

[Clinch Leatherwood]

I have to ask myself, what is more likely to happen, a model locking on to a correct solution 120 hours out and showing that same solution for the next 10 cycles? Or a model in the ballpark at 120 hours, then waffling and trending toward a solution in the next 10 cycles as it gets more information and into it's wheelhouse time-wise? It's not anything about either of the models (or even strictly scientific actually) but I am more comfortable with how the GFS is evolving. I'd rather see waffling this far out, then a trend being established, then what we want as the final solution evolving inside 60 hours, than the what we want as a final solution looking us in the face at 120 hours out.

I'd agree with that across the board. The outliers are falling towards the consensus in both directions (aside of the NOGAPS).

Sadly being in the bullseye at 120 hours up here essentially tells me it's going to end badly one way or the other when we have agreement. I'm glad for one there's still model uncertainty.

[Ian]

it appears to me the gfs shows a nice pattern change at 168 to warmer.

http://moe.met.fsu.e...sure&hour=168hr

when a pattern is in flux isnt that a possible window for a big storm to develop?

ask heather archambault

[vinylfreak89]

First, I don't want to expand too much, but my citing of PVA wasn't meant to imply that this is what to always look for and/or is causing the surface reflection to be where it is. I was just saying at first (quick) glance things seem to be consistent given what the mid/upper levels looked like.

I honestly haven't looked much at the GGEM (other than the few plots posted on this forum)....so I'll defer to others if they want to attempt to explain the difference in the evolution (and why the trough doesn't seem to really want to go negatively tilted).

no i know that... just directed the question at you because you seemed to be discussing some of the finer aspects... just wondering in general why the PVA was more strung out.

[showmethesnow]

Haven't seen the NAO forecast, but many of the big ones over the years have occurred when the NAO was increasing (which includes decreasing negativity).

Was checking this earlier in the day on some of the previous runs. They all have been showing a pretty good drop.

[kpantz]

Was checking this earlier in the day on some of the previous runs. They all have been showing a pretty good drop.

Sweet. In a Nina, we can use all the statistical support we can get!

[showmethesnow]

Was checking this earlier in the day on some of the previous runs. They all have been showing a pretty good drop.

Actually gave the 6Z. Here's the 12Z. Shows an even bigger drop.

[earthlight]

[usedtobe]

20 percent of the gefs members now give dc .50, that's up from one giving the area 0.1" inch on the 06Z gefs run.

[WBRE Wx]

Good (better?) 12z GFS Ensemble support. Quick look shows 3 major (ala Euro) hits, and the rest at least graze coast and come very close. A good trend...

[showmethesnow]

Over the last several runs more and more members have been picking up on a Euro solution thou with more of a south east track. I was wondering if the south east bias also works with its members and not just the operational.

[LakeEffectKing]

Anyone here going to do Euro play by play....or do I have to go hunt down tombo in the regional thread??

[yoda]

12z EURO re Tombo

hr 18 has a h5 closed low over las vegas

through hr 24 everything is pretty much the same so far to 0z, except 12z has a little more confluence over ne

through hr 30, everything still pretty much the same..s/w might be a hair weaker...looks like a little stronger riging in the front

hr 36 same as 0z pretty much

[pazzo83]

hr 30 is basically the same too, although he says the s/w might be a tad weaker.

[Midlo Snow Maker]

Anyone here going to do Euro play by play....or do I have to go hunt down tombo in the regional thread??

S/W still closed at 24hr. same spot so far atl low hair east

[pazzo83]

hr 36 and 42 everything basically the same

[jconsor]

The gradient on the 12z GFS is similar to the blizzard of '78, just shifted east so the highest winds are just offshore. Verbatim, the 12z GFS has ~50 kt winds for 6 hours at Chatham, MA: http://wxweb.meteost...shtml?text=kcqx

It also has a 65 to 70 kt jet at 850 mb impacting much of SE New England including SE MA, RI, SE CT and the Twin Forks of LI.

I can't find any recent nor'easter that produced 50 kt or greater sustained winds. Here are the highest winds in some recent ones:

March 1962 "Ash Wednesday" Nor'easter -

BID gust 73 kt

Feb 1978 Blizzard -

BOS sustained 44 kt, gust 69 kt

CQX gust 81 kt

FMH and ACK sustained 35 kt, gust 55 kt

ISP sustained 40 kt, gust 52 kt

Halloween 1991 "Perfect Storm"-

CQX gust 68 kt

ACK sustained 40 kt, gust 55 kt

Dec 1992 Nor'easter -

LGA sustained 45 kt, gust 67 kt

Mar 1993 Blizzard -

LGA sustained 45 kt, gust 60 kt

BOS sustained 47 kt; gust 70 kt

PVC sustained 41 kt; gust 70 kt

Fire Island, NY gust 79 kt

Mar 2010 Nor'easter -

JFK sustained 45 kt, gust 64 kt

ACY sustained 35 kt, gust 58 kt

Bridgehampton, NY gust 60 kt

[Midlo Snow Maker]

hr 42 S/w Dead on with 0z bit more ridging, atl low further ne

[Clinch Leatherwood]

48hr EC v GFS both from 12z at 500mb

[dtk]

oh silly me.. I thought I was in a model thread for some reason.

I think people are entitled to post where they want....it's not hard to follow along if you open a second window.

[stormtracker]

Any reason he's not posting here?

I don't understand why he won't either, after the staff has asked him to several times. We've given up at this point and we're not going to beg. If there is any member here that has it early and would be more accommodating to our requests, it would be greatly appreciated.

[forkyfork]

the big player is the energy in the northern plains... focus on that

[yoda]

hr 54 closed h5 low just northeeast of whichita falls, tx...mod precip in tx and ok....lgt precip northern plains to tx

[Midlo Snow Maker]

hr. 54 closed low same spot heights are a tad higher on the east coast

[Radders]

Very minor differences between 0Z and 12Z at 60.. S/W basically in the same spot, maybe slightly higher heights over the east.

[Midlo Snow Maker]

60 hr S/W still closed a little north, atl low scooting out heights are higher still on the east coast