New Year Storm Thread 12/29-01/01

[Yukon Cornelius]

7 minutes ago, Ginx snewx said:

3k NAM destroys Hippy and really likes Western RI hills for ice 

Ugh - genny on standby, but hoping not needed. 

[ORH_wxman]

4 minutes ago, moneypitmike said:

What's your take on part 2?  Looks like shit to me.

I haven't looked closely at part two. Sfc looks too warm on model guidance though over interior MA for part 2 imho....I'd slice guidance temps if I was making a forecast probably unless I'm missing something. 

I'll prob take a closer look at everything tonight. I just got back from NJ today after a 5 hour drive. 

[Torch Tiger]

A lot of negativity by the cold clowns regarding this storm and winter in general. You have some icing and sleet coming, what's the problem? This could be a cold rain with zero ice, zero sleet, absolutely nothing. Enjoy

[CoastalWx]

11 minutes ago, ORH_wxman said:

This storm is unique in that the coldest portion of the storm is not at the onset like in a lot of CAD setups. This could be a cold rain for several hours in areas like BOS and nearby suburbs...hell even ORH could start as cold rain but then the drain starts accelerating. It's pretty breathtaking actually how aggressive that high is. It could go to ZR and then to pellets. 

If it starts as ZR/IP, then basically the entire storm will not be liquid where that occurs because it only gets colder as we go through the event...speaking of the main part 1 portion, not that second round on Tuesday. 

Yeah that is what’s making this complicated. It’s a rare event. Look at 925-850. It actually starts to turn NE and advert cold air in!  That’s just something that doesn’t happen. Wicked HP

[HIPPYVALLEY]

28 minutes ago, Ginx snewx said:

3k NAM destroys Hippy and really likes Western RI hills for ice 

Pain in the ass! My driveway just melted off yesterday.

[The 4 Seasons]

14 minutes ago, moneypitmike said:

New map.....Look out Sandisfield/Blandford.

For most of us, looks like we'll have some scenic views of the woods encased in non-damaging ice.

Man, whoever lives in that little dot SW of I90 is going to get 1-2" of icee and be without power for weeks and months, total destruction.

[ma blizzard]

9 minutes ago, HoarfrostHubb said:

Any similarity to an early December ice event two or three years ago?

12/23/17? super impressive cold tuck overnight sat set the stage for a not well forecasted 1/4"-1/3" for a lot of central / eastern MA 

not sure if you are thinking of this one, but that's what came to mind. 

[moneypitmike]

4 minutes ago, The 4 Seasons said:

Man, whoever lives in that little dot SW of I90 is going to get 1-2" of icee and be without power for weeks and months, total destruction.

I feel for those 12 people.

[HoarfrostHubb]

3 minutes ago, ma blizzard said:

12/23/17? super impressive cold tuck overnight sat set the stage for a not well forecasted 1/4"-1/3" for a lot of central / eastern MA 

not sure if you are thinking of this one, but that's what came to mind. 

Maybe that’s the date.  I thought it was earlier in the month.  

[ORH_wxman]

3 minutes ago, CoastalWx said:

Yeah that is what’s making this complicated. It’s a rare event. Look at 925-850. It actually starts to turn NE and advert cold air in!  That’s just something that doesn’t happen. Wicked HP

Yeah it could actually go from rain to pellets to snow back to pellets in that order up near MA/NH border. Lol. 

[STILL N OF PIKE]

So basically ...if forecasts are based off only models that are under forecasting the cold press at the surface then we have a heck of an icing situation potentially in RI and CT that is under forecast 

[Ginx snewx]

3 minutes ago, STILL N OF PIKE said:

So basically ...if forecasts are based off only models that are under forecasting the cold press at the surface then we have a heck of an icing situation potentially in RI and CT that is under forecast 

I guess you could say that about lots of parameters in lots of storms.

[ORH_wxman]

Just now, STILL N OF PIKE said:

So basically ...if forecasts are based off only models that are under forecasting the cold press at the surface then we have a heck of an icing situation potentially in RI and CT that is under forecast 

Yes. Hard to say where the sfc cold really stops pressing. It could get into central CT or it could have trouble getting past the south ORH hills/Union CT area. The cold looks pretty deep though...as evidence by that 850-925mb layer going crazy during the event getting pushed way southwest....so that tells me that the sfc will prob go further SW than models think. You have like low to mid 20s in NH and ME with pressures that are having a real problem lowering. Those are going to fly southwest...where do they stop though? That's the tough part. They'll make it to ORH...maybe to Kevin too? 

[CoastalWx]

RPM is sort of weenie here. 2-4” followed  by hours of pellets. 
 

Temp forecasts are tricky here. Not ideal to CAA off the ocean, but it’s so cold aloft that it might slowly drop temps to near freezing at the surface. Type of deal where it’s like 33 here and 30 on top of blue hill. 

[HoarfrostHubb]

6 minutes ago, STILL N OF PIKE said:

So basically ...if forecasts are based off only models that are under forecasting the cold press at the surface then we have a heck of an icing situation potentially in RI and CT that is under forecast 

Or the opposite could happen and just rains to Maines 

[CoastalWx]

This also may be a good example of models adjusting as we get closer to the event. Adjust to better or for worse, but as they assimilate with current observations they should have an idea starting tomorrow.

[Damage In Tolland]

This is a fantastic AFD. Gives you the Drag “chills” feel reading it 

Per collaboration with surrounding NWS offices, Winter Storm Watches
are now hoisted for western and central MA into northern CT. This is
mainly due to the potential for a prolonged period of freezing rain
and sleet. Though sensitivity to low-level thermal structure and
precipitation type changes results in some uncertainty in forecast
ice and snow/sleet accumulations, model solutions are coming around
to the idea of potentially significant icing with potential for tree
damage, power outages and transportation impacts in the Watch
area.

First part of this expected precip event looks to affect the region
starting Sunday evening. Warm-frontal precipitation is expected to
overspread from central and southern NY into Sunday night. Though
surface temperatures initially support rain as a predominant weather
type, northeast ageostrophic flow related to an in-situ high
pressure ridge/wedge over ME/NH will draw increasingly colder/sub-
freezing low-level air southwestward mainly across areas north and
west of Interstate 495. This process will facilitate a changeover
towards sleet and freezing rain in these areas, with warm-nose
temperatures between +1 to +4C following the ECMWF/NAM guidance.
Surface ridge over northern New England remains essentially in place
through most of the first part of the event, and this will maintain
and lock in sub-freezing surface temperatures across several hours
in these interior areas. Precipitation appears most focused with
this first portion of the event during the pre-dawn into Monday
afternoon hours with impact potentially to both commutes. In this
period, of some concern is NAM-based guidance indicating a corridor
of elevated instability (up to 150 J/kg) on the nose of a SSW low-
level jet of 40-50 kts, which may help to enhance freezing rain and
sleet accumulation rates. Temperatures across most of the South
Coast and near/SE of I-95 should remain above-freezing supporting
predominantly rain.

Later Monday night, surface winds become east to east-southeast as
we await the second part of this event, taking the form of a
developing coastal cyclone that looks to progress from the east
coast of NJ towards SE MA by 12Z Tuesday. While the GFS remains on
the eastern/offshore side of the guidance envelope regarding this
system, ECMWF ensemble membership is rather tightly clustered either
near the MA E coast or inland. A closer-inland track appears
preferred and follows the ECMWF/GEM solutions.  System looks to pull into
coastal Maine by the evening of New Years Eve, with winds becoming
westerly and cooler air filters in on west winds.

The Winter Storm Watch was hoisted in areas where significant
freezing rain accretions are possible, with amounts up to a half-
inch forecast. It sometimes can be difficult to reach Warning
criteria purely from freezing rain accumulations alone. Small
changes to low-level thermal structure will make significant
differences in observed sleet/freezing rain accumulations, and
pending subsequent QPF and accumulation trends, some of those
areas currently in the Watch may end up becoming converted to
Advisories on that basis. The potential exists for significant
icing in portions of the Watch, however, and this is especially
the case for parts of the hills in Worcester and Tolland/Windham
Counties and into the eastern slopes of the Berkshires given
northeast/east upslope flow. Indeed, trending on the lower end
of that range by aftn.ndividual NAM/ECMWF/GFS model guidance
freezing rain accumulations are quite substantial, and while
likely overdone, in some cases are over three- quarters of an
inch. Further expansion of the Watch could be needed in
subsequent updates.

[RUNNAWAYICEBERG]

A bun for ‘chills’ and another for not resizing the font.

 

[DomNH]

A bun for bolding the section that mentions Tolland County.

[Damage In Tolland]

Buns flying like Helloween candy. We take!

[ma blizzard]

I'd be shocked if the meso models don't start trending colder at the surface as we get closer .. there is no doubt the models are underestimating / not properly resolving the ageostrophic component. We have seen this movie before  

As TIP mentioned earlier today, I wonder if there will be a pseudo CF feature separating the drainage flow in the interior from strong easterly flow from the coast? 

 

[Damage In Tolland]

So naked. So free 

[dendrite]

Just now, Damage In Tolland said:

So naked. So free 

Naked and afraid?

[Typhoon Tip]

The 18z NAM offers up 0 or < 0 C at every sigma level from 800 mb down to the tarmacs for Logan during the first 12 to 18 hours of this thing.

That's a tick down by some, and it now is even colder than the shaved .5 C Euro at this point.   And if it were not [ probably? ] for an obscenely elevated warm layer, that would be probably 5" of snow in that QPF realization, prior to ZR intrusion. If not, than folks thinking sleet are in for surpriiiiise. I'm also noticing a fairly potent IB signaled in there, too, with 9.2 units of UVM during the front work - not bad!  Before quells into a more middling lift on-going saturation, but by then we are soaring at 800 to 4 or 5+ C so that's sleet and ZR most likely at least to that latitude over eastern zones.

In the interior, this sags by some..how much is now cast-able.  But I would suggest that is also offset by the fact that this is warmer WNW of ORH in this type of synoptic ordeal...with essentially what amounts to a powerful BD advection coming in around a third of the way through, a marginal cold rain/ice/IP situation profiles downward and becomes non-liquid in character at that point in time. It's likely IP in ALB while snowing at the east end of the Mohawk Trail for a stint during the band of instability burst. Overall, after brief snow, looks like mid or upper 30s southwest of HFD where cold rain and a few pings, to low 30s/30 down rt 2 with IP and mangled aggies, while it may be heavy IP/noodles at Logan. Then everyone is over to IP NE, as we convert this to a moderate infrastructure ice concern ( more?) as said NE thrust arrives and probably sends a wave of crashing DP /temp deep into CT/RI underneath ongoing WAA way above.  That's what this looks like to me, and even the higher res mesos will under do that fantastic static stability/BL forcing of having a newly fresh polar +PP wedging in like this.  It's just going happen this way I feel. If not... oh well - otherwise consider one's self warned.

I'd say if anything warning would be met near that interface of IP and accretion where fall rates and temperature combine for proficiency.  Where it is snow/IP around Manchester NH, may be high end advisory - until later periods when coastal evolution may enhance a temp CCB in that region up through coastal Maine.... It's tough sending headlines when you got storm acting seamless across different intervals.  Heh... pun intended, it's like "the cloud" storm. 

[weathafella]

7 minutes ago, Damage In Tolland said:

So naked. So free 

Me too. Just got out the shower and not happy with the mirror reflection....not happy at all!

[powderfreak]

Looks like an interesting system... I think we could get 3-5” of snow/sleet up this way.  Dense stuff and good upslope signal on Wednesday to follow it up.

[NorEastermass128]

WU bumped up totals for NE MA towns from 2-6” earlier to now 6-10”. 

[CoastalWx]

5 minutes ago, NorEastermass128 said:

WU bumped up totals for NE MA towns from 2-6” earlier to now 6-10”. 

I think we sell.

[NorEastermass128]

9 minutes ago, CoastalWx said:

I think we sell.

I think that’s a safe bet. 

[Sugarloaf1989]

1 hour ago, moneypitmike said:

I feel for those 12 people.

It's more than that, Otis Ridge is located there. A small mom and pop ski area. Hopefully they don't get alot of ice storm damage.