Feb 15 clipper/redeveloper

[Ginx snewx]

Seriously, looking at all the majors, power issues galore on the outer Cape even with a start to rain if it does, heavy wet plastering with tight wind fields shown.

[dendrite]

GEFS mean similar to the op. Right over the BM.

[wxsniss]

no , not safe to say any max of 3-6 with this for ORH, could be more depends where banding on this tight little NUKE sets up

 

if we could only get it to stall a bit

 

Yah you're not the only hoping for that...! We got ourselves a nuke, how can we get the most bang for our buck out of it.

 

See the 6z Sunday maps I posted above... positioning/strength of ULL over Quebec will be one factor in allowing this to track even further west and not exit so quickly.

[moneypitmike]

Man---this is pretty interesting.  BOX is pooh-poohing give GC less than an inch, Albany going 2-4 for their zones.

 

BOX has been pretty good with things out this way this season.

 

Either way, up in Bartlett.  Quite the adventure driving down through Crawford Notch.  SN+/blowing+, icy 302.  Ton of snow here on the ground.  GYX going for 2-4.  Nice add.

[Baroclinic Zone]

me thinks the thermal profile is a bit off on the GFS and that is shoving precip further west than it should.

I do believe the 12z GFS more than the 18z GFS at this time. I'd give it some credence but I would not go 100% all in on it.

[dendrite]

GEFS mean similar to the op. Right over the BM.

1" liquid for BOS.

[weatherbob]

I honestly thing we're getting creamed by this.  I think all guidance tonight will come in robust for alot of CT/MA/NH/ME.

You forgot RI

[Typhoon Tip]

BMJ convection scheme adjusts the sounding towards a pre-determined, post convective profile derived from climatology, in the NAM.

 

Therein is an operational problem for me because this is rather stressed solution relative to climatology.  It makes the NAM (if this is still the convective parameterization) a bit suspect right off the bat.   

 

"Link to Large Scale Forcing:  There is no direct link of the BMJ scheme to large scale forcing."  

 

Hmm.. think about this for a moment... if the BMJ physics sniff out and detonate instability over the g-stream baroclinic zone, does that declaration then suggest those latent heat releases are ...disconnected from the synoptic evolution of the cyclogenesis??  If so, bad bad bad, particularly if those process are interfering with large scale forces.

 

It could be why we are seeing an east bias to the NAM relative to the stalwart GFS westerly positions.  If you look at the NAM's depiction of the surface pressure pattern nearing 21 hours from now, you see it is "oblonged" seaward ... stressed in that direction, and poised to actual center jump the low to the right side of the baroclinic axis.  I think that is wrong, and in part if not in total caused by the fact that it's stability parameterization type is not best suited for processing large scale synoptic events.

 

It may also be part in parcel why the NAM sucks to begin with ... other than convection in summer, in the Plains and over Florida.  But that's a digression.

 

The GFS on the other hand . .. its strengths and weakness using the AS scheme do not appear to favor it one way or the other.   This isn't to say the GFS doesn't get afflicted by CFB; relative to what is being modeled for the weekend, it seems the NAM's handling is dubious.  

 

As to why the Euro is now correcting west (as a plausible unfinished trend....), I don't have an immediate explanation for that.  I don't get to see detailed levels, and intermediary intervals... But I would suggest starting here:

Errors in the mass fields may result in areas of grid scale convection... It is entirely possible the model has had some convective bug-a-boos of it's own rite. 

 

Either way .. I am virtually certain that these models et al are not handling the immense complexity of the antecedent CAA over the G-stream, then having to deal with a negative tilted S/W with a 110kt 500mb jet core(s) riding over top.

 

I hate to say, but the best model of choice for me right now is the apparent stable looking GFS, both of continuity overall, but the overall mass fields both centric, and surrounding the cyclogenesis region.  Also, any "discontinuity" that is defined, is actually been along a predictable outcome due to persistent trend.   

[wxsniss]

18-21 hour maps are the key on the "all others" vs GFS camp.

 

At 15z Saturday the GFS has a 998 mb low consolidating inland over NC west of convection that it has run right up to the outer banks.  The other models are all diffuse, with the convection further offshore by 50+ miles.   From there the GFS fires the convection further, really goes to the town with the mid level centers right under it and wraps the entire thing much closer to the coast. 

 

That's the crux of the difference.  All of the other models key on the outer convection and spin up the low from there which moves northward.  The GFS says no...starts to spin up the low inland over the Carolinas behind a line of intense convection it fires across the Carolinas.

 

We need a Tippy 40 paragraph posts to explain which type of model may be right or wrong here, but that's your difference and IMO it's that simple.  One model camp is right, one is wrong.

 

IMO it's not really a first to the party thing.  It's either right or wrong on that convection.  ALL models are trending stronger and naturally that'll lead to more convection which is either increasing the "rightness" of the GFS or causing it to fall down.  TBH I have no idea which it is.  Feedback is an overused term and IMO more times than not in the last few years when we thought it was effecting the outcome it wasn't

 

Good stuff, agree and have posted similarly.

 

Out of my pay-grade, but I wonder if the GEFS are as sensitive as the GFS to this bit of convection shaping the midlevel centers?

Because the GEFS have been solidly consistent with the op.

[Spoons56]

Thank you Tip! Those are the types of posts that keep me glued to this forum during the winter.

 

I'm thinking we see the GFS tick very slightly west at 00Z and the EURO trend toward it (although not all the way). There will be some scrambling in both forecasts and preparations tomorrow AM in central and eastern New England.

[Damage In Tolland]

Wow at the Gefs. That's huge. Lends credence and confidence

[Patrick-02540]

OKX just went watch for 6-8 for SE CT

Well, you know, I just want a solid 4 inches here in western CT.   Do I have a chance?

[nutmegfriar]

Twitter comes alive when a model shows a big storm.  It never matters which model.  All that matters is A model shows a storm and the dingbats strike up the band.

[Dsnowx53]

Closed 700mb in SE Jersey, and even a mini TROWAL as warm heights try to bend back to the SW out ahead of the 700mb low ... producing nice omega underneath the bending back warmer heights and pretty good snow for most of SNE. Not nearly as defined as the TROWAL with yesterday's event, but there are still subtle hints at it. 

 

 

700mb briefly opens back up, then becomes a classically tight closed low on the Cape. That would mean heavy banding for C CT and eastward...

 

[Dan76]

Offshore     

 

HURRICANE FORCE WIND WARNING
 

[Dsnowx53]

Actually, 700mb appears closed off at 30 as well. Wow. Look at all that lift. That strong lift would help to increase ratios, too. Quick-hitting Miller B bomb to say the least. 

 

[HoarfrostHubb]

Someone is getting 12-15" in a short period of time

[jamesnichols1989]

Hurricane Force Wind Warning leads to potential for bombogenesis across the outer coastal waters.  850mb jet increases to 80-90 knots towards early Sunday morning as storm system makes closest approach to Cape Cod.  Winds could gust as high as 60 knots for Cape Cod and the Islands Sunday morning as storm makes it to the benchmark.  This is a highly energetic system and should not be taken lightly from the BOS to PVD corridor points eastward.

[CoastalWx]

Not to be a weenie, but I've seen enough times where some of the banding signatures scream dumpage. These are signals for like 2-4"/hr stuff.  The issue here is that places that get this might only see this for an hour or two..but anyone who may be lucky enough to get into this is going to get smoked hard. Perhaps 3hrs?

[JC-CT]

I think Steve gets crushed

[N. OF PIKE]

James enjoy this system man.....i know you live for storms like this. You should get some pics/video footage if you can...would make good memories.

 

Looks like a relatively quick hitting period of very good lift.. probably max's around 14-15 or so IMO.....if the ULL in quebec (that was posted last hr) is able to aid our system in tucking in a tad closer and slowing the exit maybe we see a 8-10 hr period of great lift for SE areas.....seems to me max amounts would be 20" inches...(potential wise if everything went perfect) but i can't see going for more than a 10-15 max accums for cape at this point

[Damage In Tolland]

Not to be a weenie, but I've seen enough times where some of the banding signatures scream dumpage. These are signals for like 2-4"/hr stuff. The issue here is that places that get this might only see this for an hour or two..but anyone who may be lucky enough to get into this is going to get smoked hard. Perhaps 3hrs?

Reminds us of Jan 26-27 2011

[N. OF PIKE]

14-20 in the point and click for extreme east maine on sat nite....alone.  Don't see totals like that for a overnite/day period often

[Mr. Windcredible!]

GFS gives central CT almost 10"...NAM gives barely a coating. Gotta love the agreement there 24 hours out. Somewhere in between would be pretty decent though. The fact that the GFS didn't just hold at 18z but ramped up is a bit curious. Hopefully the 0z runs offer some increased clarity on a final solution...and in a good way.

[dryslot]

14-20 in the point and click for extreme east maine on sat nite....alone. Don't see totals like that for a overnite/day period often

CAR snowfall map was 18-24"

[jamesnichols1989]

With the GFS ensemble means around 974mb east of CHH by Sunday morning, lends to perhaps the surface low will reach 970mb east of CHH.  Always go lower with surface pressures than an ensemble mean SLP.

[weathafella]

With the GFS ensemble means around 974mb east of CHH by Sunday morning, lends to perhaps the surface low will reach 970mb east of CHH. Always go lower with surface pressures than an ensemble mean SLP.

James, we love you and are hoping you get buried. That said however, the statement of slip doesn't make sense. What if you had 2 member with a ridiculous bomb of. 940, a some 950, and the rest 988. The ensemble mean would not really reflect how meh it is.

Think snow!

[JC-CT]

James, we love you and are hoping you get buried. That said however, the statement of slip doesn't make sense. What if you had 2 member with a ridiculous bomb of. 940, a some 950, and the rest 988. The ensemble mean would not really reflect how meh it is.

Think snow!

Weaker SLP usually results from timing differences, but in case they are all dead in sync.

[TalcottWx]

James, we love you and are hoping you get buried. That said however, the statement of slip doesn't make sense. What if you had 2 member with a ridiculous bomb of. 940, a some 950, and the rest 988. The ensemble mean would not really reflect how meh it is.

Think snow!

Jerry, 

Wish I had that cape house I'm planning on owning in 10 years. 

Dream scenario: NH House and Cape house, and home in Southie. How could you go wrong? Every single storm you would be in the crosshairs at one locale.

[JC-CT]

988 is meh when models tickle 970.

Yes but the scenario laid out was almost unanimous consensus at 988. Still could be a decent snow...didn't Will say 2005 was something like 995, but just rapid bombing from like 1010?