Discussion-OBS Noon Wed Feb 5-Noon Thu Feb 6 Snow-ice changing to rain Thu morning except ice may linger through Noon parts of I84 corridor.

[LibertyBell]

27 minutes ago, RU848789 said:

All true, but the bottom line is that it's a close call on most model soundings and will likely be a close call in reality, plus no model in the world can get the entire column thermal profile exactly right at each time step, so this will be more of a radar and observational event than most.  Would love all snow/ sleet with minimal ZR and rain...

these kinds of storms are usually nowcast events

[eduggs]

4 minutes ago, LibertyBell said:

Even the parts of SNE that are east of us? We've seen a few examples where, for example, the cape and other extreme coastal parts of New England change to rain before we do.

So if the storm and the 850mb low both go south of us, it's simply a bowling ball storm and not an SWFE?

SWFE usually refer to cases with a surface high northeast of New England and an 850mb low passing to our northwest. In these cases, Cape Cod often stays frozen longer than our northern suburbs due to CAD or simply a warm front taking on a NW to SE orientation. If the 850mb passes to our south, it wouldn't typically be referred to as a SWFE. But I don't like the term, and again, it does not have a precise, scientific definition.

[Allsnow]

The euro continues to be very warm with very little frozen to start with this system. 

[weatherpruf]

4 minutes ago, Allsnow said:

The euro continues to be very warm with very little frozen to start with this system. 

Looking back over the years, we do tend to get these sleet events around this time of the year though. FWIW.

[NorthShoreWx]

All of the models I looked at showed between 0.25" and 0.50" of qpf, mostly 0.4" and less.  The coast is usually at risk, but for anyplace (including closer to the coast if they get lucky) that gets an inch or two of snow followed by sleet, there won't be much left after a complete changeover.  Maybe some light rain or drizzle?

Not saying it won't changeover, but this is not a prolific amount of LE.

 

[MANDA]

1 hour ago, BoulderWX said:

See ya on the next one. Some of us are quite happy with another couple of inches. 

Hope ya get it on this first one.

[SnowGoose69]

48 minutes ago, Allsnow said:

The euro continues to be very warm with very little frozen to start with this system. 

Its not tremendously different on thermals, it simply has no QPF til like 13Z

[The 4 Seasons]

6 hours ago, EastonSN+ said:

Thanks for this, please keep posting this forum.

Ok. Here's my thoughts right now..

Euro definitely the farthest to the right with warm air and SLP riding up north. The other models seem to be all in agreement with the low transfer happening south of us going over around ACK ish, helping to lock in the cold air. 

Snow growth isn't impressive at all. Most of the lift occuring outside the DGZ on most of the models ive seen. Which is pretty typical with these type of systems punching in warm air aloft as we get going. 

In terms of snow, id probably lean pretty conservative. Still looks like its going to be a mess though on Thursday and probably a tough call for schools. But with the sleet and freezing rain forecast i think most will close.

I think the NWS has right idea. I think you're going to be hard pressed to see much more than around an inch of snow in and around the city into LI. IF that, maybe just a coating 

 

[Allsnow]

 

[Stormlover74]

Wow that's early 

[Allsnow]

Just now, Stormlover74 said:

Wow that's early 

Agreed. Afd discussion said c-inch but was concerned about frz rain/Thursday commute 

[SnowGoose69]

The 18Z HRRR sure doubling down on its idea, no notable move towards the Euro.  We'll see if the NAM begins to move towards it next few cycles

[jm1220]

I agree that with no strong onshore flow and possibility the surface low stays south of LI, there could be a period of icing for northern NYC and north shore. It’ll be hard to get that whole area above 32 without a decently strong onshore wind. Might be another situation like 2 nights ago where it stayed below 30 north of the Northern State but spiked to 36-38 south of the LIE. But it wouldn’t help with snow, it just means more sleet and then ZR. 

[winterwx21]

11 minutes ago, SnowGoose69 said:

The 18Z HRRR sure doubling down on its idea, no notable move towards the Euro.  We'll see if the NAM begins to move towards it next few cycles

HRRR hasn't been great this winter. Let's hope this is an event that it's right about, but obviously we should be skeptical. This is long range for the HRRR too. 

[SnowGoose69]

6 minutes ago, winterwx21 said:

HRRR hasn't been great this winter. Let's hope this is an event that it's right about, but obviously we should be skeptical. This is long range for the HRRR too. 

 

Yeah I'd definitely not use its thermals but the idea its generating so much overrunning precip relative to the Euro is good

[Stormlover74]

[eduggs]

26 minutes ago, SnowGoose69 said:

The 18Z HRRR sure doubling down on its idea, no notable move towards the Euro.  We'll see if the NAM begins to move towards it next few cycles

The 18z HRRR looks like classic dynamic cooling. The column initially warms enough for partial melting and sleet with possible mixed ZR. Then as precipitation intensity increases towards dawn, increased melting pulls heat energy from the air, resulting in cooling and a change back to snow.

The 18z HRRR depiction would be great. Light snow moves in tomorrow evening with a 2-3 hour burst of mixed snow/sleet overnight and tapers off mid-morning as drizzle or freezing drizzle. General 1-3" from CNJ through NYC metro, LHV, and all of CT. Most areas outside of LI and the immediate shoreline never go to rain. Fingers crossed but I'm hedging lower on snow.

[jm1220]

22 minutes ago, SnowGoose69 said:

 

Yeah I'd definitely not use its thermals but the idea its generating so much overrunning precip relative to the Euro is good

We’d definitely want that solid overrunning snow shield to be confident at getting any real accums. The SWFEs where the precip waits and waits until the cold air is gone never work out. 

[cleetussnow]

NWS has WWA up here.  I don't think we've had a snowday yet, so I doubt schools would be hesitant at all to pull the trigger given the timings.  

[eduggs]

Dynamic Cooling
   

[EastonSN+]

[Stormlover74]

Rgem much slower than nam. Doesn't even begin til after 6am Thursday 

It's also showing all frozen but temps and 850s above freezing for most