December 19th-20 Storm Thread III

[Damage In Tolland]

Snow

White Christmas 100% for all of SNE

[Mr Torchey]

Snow

Congrats Phil, new baby boy, and a nice little snowstorm to boot, you deserve it out there, ENJOY!

[Baroclinic Zone]

Snow

One can hope for a Christmas miracle.

[CoastalWx]

exactly.....now let's see if this is a 9'th inning trend.

the once bitten twice shy group is emotionally burned from the model flip flop IMO and is traumatized from getting their hopes up again. (and before you labe this pure weeniesm as i'm sure your mentally inclined given the above.

a very good met i read on the board "barcolonic instability" said

there is a chance that the models don't get this right to the last minute (due to the set up) coupled with the following

scott do you remember (as i have been searching all morning to no avial) the process the HPC was alluding to on tues of this week....when they were tossing the euro....and mentioning the SST anomalies and rapid deepening of surface lows and barcolinic instability resulting from said SST anomalies would play a part in the track and strength of the system but is not modeled well?

I think they were trying to refer to "static stability" as a process to help kick off cyclogenesis. The only other thing I could think of was that the colder air moving into the southeast would help sharper the baroclinic zone that exists near the Gulf stream wall.

I would not expect a huge last minute jump with the low right now, but the H5 pattern normally would have me thinking a little further west. I think part of the problem is that the baroclinic zone is already pretty far offshore, so the low would have to perform a herculean effort to come back nw. I just don't see areas like ORH and HFD getting it right now. Besides, we don't know if the NAM is up to some old tricks. Wait until 12z comes in fully.

[ski MRG]

Female singer who had a few hits late 60's -early 70's. One of her biggies was Wishin and Hopin ! It's fair to say that she has more than a few fans here, myself included.

Ah, vaguely remember that now. I'm not wishin' and opin' as much as I'm relying on stats for my area. Even a below average snowfall year here provides plenty of snow. Of course there have been true duds but they are few and far between. If this Winter were to turn out tha way there is nothing that can be done abouit it. To grouse about in an irratible funk seems silly to me. More than anything I hate seeing my fellow New Englander's act like MA cry babies.lol

[Boston-winter08]

not sure if this has been brought up, but the 09z SREFS trended west, as well...not to mention, the 6hr frame from the 12Z and the 12hr frame from the 6Z NAM have marked differences

[ski MRG]

I think they were trying to refer to "static stability" as a process to help kick off cyclogenesis. The only other thing I could think of was that the colder air moving into the southeast would help sharper the baroclinic zone that exists near the Gulf stream wall.

I would not expect a huge last minute jump with the low right now, but the H5 pattern normally would have me thinking a little further west. I think part of the problem is that the baroclinic zone is already pretty far offshore, so the low would have to perform a herculean effort to come back nw. I just don't see areas like ORH and HFD getting it right now. Besides, we don't know if the NAM is up to some old tricks. Wait until 12z comes in fully.

So, in other words you're bucking the model trends of the last 36 hrs and are saying we can all lock in for a massive snowstorm. Cool, thanks Scott, I really respect your opinion and I'm going to tell everyone what you've forecst. I'm pumped now. Nice.

[Randylee]

Look on the bright side, we only need some minor changes in the upper levels for some action this upcoming week.

The players are on the field.

I am not going to get too nervous about the amount of snow until after Xmas. That's when things normally get going anyway.

At least I have snow on the ground, be it only about an inch or less.

[Ginx snewx]

I'm going to take a page out of Ray's play book. I don't care if Boston never sees snow again. As long as it snows at the ski areas here on North. I'm not sure any of the Mets here were duped. I remember Scott offering up some healthy doubt. One model run does not a KU make. I for one didn't get overly jazzed. I'll wait for a threat that doesn't have as many moving parts and has a well modeled, consistent track. It's White here now and will likely get Whiter as we go on in time.

It was actually two straight runs for the Euro and it's ensembles as well as seven out of nine GFS runs as well as Nam, GGEM, Nogaps, JPA , all together. And yea many mets were cautious but they certainly were very very surprised when the whole thing sh it the bed.

[Clinch Leatherwood]

Looks like this is all generated by the northern stream vortmax as it rounds the base of the trough.

I had a nice sleep, enjoyed time with the kids and laughed as the NAM 0h came out.. This is our only shot and I still think there' s a major issue with feedback which is preventing a much more forbidable comma head from showing.

It's not over yet but I've come to another realization.

Model performance has been so bad for a year it is STILL too far out to really care. Tonight maybe, first thing Sunday sure. This could be a fun run, but it is still too far out.

This is two main runs in a row that have ticked back 100+ miles.

[Baroclinic Zone]

I think they were trying to refer to "static stability" as a process to help kick off cyclogenesis. The only other thing I could think of was that the colder air moving into the southeast would help sharper the baroclinic zone that exists near the Gulf stream wall.

I would not expect a huge last minute jump with the low right now, but the H5 pattern normally would have me thinking a little further west. I think part of the problem is that the baroclinic zone is already pretty far offshore, so the low would have to perform a herculean effort to come back nw. I just don't see areas like ORH and HFD getting it right now. Besides, we don't know if the NAM is up to some old tricks. Wait until 12z comes in fully.

Yup, the NAM is usually 2:1 overdone

[CoastalWx]

I had a nice sleep, enjoyed time with the kids and laughed as the NAM 0h came out.. This is our only shot and I still think there' s a major issue with feedback which is preventing a much more forbidable comma head from showing.

It's not over yet but I've come to another realization.

Model performance has been so bad for a year it is STILL too far out to really care. Tonight maybe, first thing Sunday sure. This could be a fun run, but it is still too far out.

This is two main runs in a row that have ticked back 100+ miles.

The comma head gets practically gets to the coastline of pym county.

[cpickett79]

12z has an earlier phase and wraps the storm almost 100 miles closer to the coast than 6z

Looks like this is all generated by the northern stream vortmax as it rounds the base of the trough.

Based on what I am reading things may be trending closer, but what are the chances there is a significant change? Not gonna happen right?

well perhaps this could have something to do with it

This event has to be one of the most sensitive potential cyclogenesis events I have seen in a long time dependent upon so many small scale weather features interacting with one another at the right time. That said, there is a distinct possibility the models don't get this right all the way up until the event. Will be interesting to see if they ever actually catch on to a definitive solution, but there is an outside shot (small, but a chance) they don't catch on until the very last second.

.....and weenies embrace that mentally intoxicating sensation to be pulled back in

[Ginx snewx]

Hey Steve, what do you think, SR skiing on 57 trails today. Not bad.

All eight open too, should be nice in the AM but icy PM fast stuff.. Man they do such a great job up there.

[CCPSUSuperstorm2010]

Scott, how do you forecast the presence of the comma head, like what do you look for, other than the radar reflectivity?

[CoastalWx]

well perhaps this could have something to do with it

.....and weenies embrace that mentally intoxicating sensation to be pulled back in

Don't be pulled back. Count your blessing if you see flurries in Framingham.

[Ginx snewx]

Snow

Heavy heavy diaper duties at 0300 watching the snowfall in the floodlight. Everyone OK?

[Clinch Leatherwood]

The other big change I think we're seeing is the feedback is resolving. Look down well east of the carolinas, h24 at 12z vs h36 at 0z.

Notice those spurious type 500mb vortices that are above the QPF bombs are shifting hard NW. That's HUGE. One more run of that going away and I think we put Bos to PVD SE back in the game.

[cpickett79]

Don't be pulled back. Count your blessing if you see flurries in Framingham.

it was flurrying an hour ago

lol i don't think it will snow in framingham more than an inch.

but i do think there could be a very sharp cut off for significant accumulating snow show up somewhere between SE mass and outer cape and by significant i mean plowable.

[MarkO]

NAM now showing nearly an inch of QPF in downeast Maine. Be interesting to see what the GFS shows in next run. The odds favor it shifting west. Be interesting to see if it does and by how much?

[Baroclinic Zone]

I had a nice sleep, enjoyed time with the kids and laughed as the NAM 0h came out.. This is our only shot and I still think there' s a major issue with feedback which is preventing a much more forbidable comma head from showing.

It's not over yet but I've come to another realization.

Model performance has been so bad for a year it is STILL too far out to really care. Tonight maybe, first thing Sunday sure. This could be a fun run, but it is still too far out.

This is two main runs in a row that have ticked back 100+ miles.

Well, we are dealing with 2 separate pieces of energy imo. The first is the southern s/w that heads offshore and blows up, the second is this piece of vorticity that comes out of the GL. If these two pieces of energy are far enough apart than that would allow the 2nd piece to dig more which I think is what the NAM is trying to show but does it a little to late for anything substantial.

[Clinch Leatherwood]

The comma head gets practically gets to the coastline of pym county.

Scott assuming the NAM is right now in blowing up the feedback (sometimes although it's feedback related we still do see clusters of storms out there that rob QPF..I do think this time it's leading ot spurious low placement and a dilluted low earlier) and that other models will show the same, I think we're good to go. The diseased comma head will fill in as we approach the system.

[CoastalWx]

Scott, how do you forecast the presence of the comma head, like what do you look for, other than the radar reflectivity?

I look for high RH and VV. It's sort of subjective but in general you probably want to see RH >80%. It looks like it would be very near the canal or cstl pym county based on my guess.

[Baroclinic Zone]

All eight open too, should be nice in the AM but icy PM fast stuff.. Man they do such a great job up there.

Nobody, and I mean nobody, can make snow like they do in the East.

[CoastalWx]

Scott assuming the NAM is right now in blowing up the feedback (sometimes although it's feedback related we still do see clusters of storms out there that rob QPF..I do think this time it's leading ot spurious low placement and a dilluted low earlier) and that other models will show the same, I think we're good to go. The diseased comma head will fill in as we approach the system.

Yeah I would def keep an eye out down by your way for sure. Even our local in house models gives you some oes and a couple of inches at that. I could see this as perhaps having one of those comma heads that do have a sharp cutoff. I still want to see the other models.

[Boston-winter08]

Yeah I would def keep an eye out down by your way for sure. Even our local in house models gives you some oes and a couple of inches at that. I could see this as perhaps having one of those comma heads that do have a sharp cutoff. I still want to see the other models.

your chances for an inch or more in boston?

[cpickett79]

http://www.intellicast.com/National/Radar/Current.aspx?animate=true

show heavier precip in upstate S.C now deveoping in central parts of southern N.C headed NE

most models had this underdone and now 12z nam appears closest with initialization in the 6 /12 hr time frames

interesting trend to watch weeniesm aside

[weathafella]

The ECM gives Boston about .5" QPF with a Norlun event Day 5, but the main storm is well offshore.

Christmas Day storm hits the Midwest hard, starts to minor out over Missouri, but then a PV phase occurs....could be interesting to follow.

[Clinch Leatherwood]

Well, we are dealing with 2 separate pieces of energy imo. The first is the southern s/w that heads offshore and blows up, the second is this piece of vorticity that comes out of the GL. If these two pieces of energy are far enough apart than that would allow the 2nd piece to dig more which I think is what the NAM is trying to show but does it a little to late for anything substantial.

The trouble maker for the last two day shas been the s/w complex SE of the carolinas that is probably largely a fixture of feedback. Sure there is some energy down there but notice the huge shift NW this run so the moisture isn't trapped so far SE.

That's the big change IMO.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/images/nam_500_024l.gif

[CCPSUSuperstorm2010]

I look for high RH and VV. It's sort of subjective but in general you probably want to see RH >80%. It looks like it would be very near the canal or cstl pym county based on my guess.

So Cape Cod, MA does get in on the comma head. Nice. We just need to see a better trend with the rest of the guidance. 00z EURO looked closer to the coast then the 12z run yesterday. I am excited for a few inches of snow. By the way, the 9z SREF probs showed about a 45-50% chance of 12" or more of snow from the BOS to PVD back to ORH. Unless that was from a different run, which I doubt, how does the SREF show such high probabilities? Also they show no accumulation for Cape Cod, MA, probably because of the mesoscale environment of the Cape and predicted low level temperatures. However dynamic cooling should be sufficient enough to offset the warmer bl temperatures.

Scott do you think delta ts will be sufficient enough for snowfall rates around 1"/hour?