Thanksgiving and Friday light snow/freezing drizzle/light rain

[ORH_wxman]

Euro looks like it actually has a bit of weenie LL convergence for T-day north of the pike and into CNE. Could be a light snow most of the day for areas like N ORH county and into a good chunk of VT/NH. It almost looks like a BDF as you head toward night...the high starts imposing a bit more NE flow.

 

Might have to watch for freezing drizzle too in some spots if ice crystal production shuts off in the clouds....which can happen if things become too much in the low levels.

[Ginx snewx]

1 minute ago, ORH_wxman said:

Euro looks like it actually has a bit of weenie LL convergence for T-day north of the pike and into CNE. Could be a light snow most of the day for areas like N ORH county and into a good chunk of VT/NH. It almost looks like a BDF as you head toward night...the high starts imposing a bit more NE flow.

 

Might have to watch for freezing drizzle too in some spots if ice crystal production shuts off in the clouds....which can happen if things become too much in the low levels.

New Euro's first run

[Damage In Tolland]

2 minutes ago, ORH_wxman said:

Euro looks like it actually has a bit of weenie LL convergence for T-day north of the pike and into CNE. Could be a light snow most of the day for areas like N ORH county and into a good chunk of VT/NH. It almost looks like a BDF as you head toward night...the high starts imposing a bit more NE flow.

 

Might have to watch for freezing drizzle too in some spots if ice crystal production shuts off in the clouds....which can happen if things become too much in the low levels.

Nothing south of 90?

[moneypitmike]

1 minute ago, ORH_wxman said:

Euro looks like it actually has a bit of weenie LL convergence for T-day north of the pike and into CNE. Could be a light snow most of the day for areas like N ORH county and into a good chunk of VT/NH. It almost looks like a BDF as you head toward night...the high starts imposing a bit more NE flow.

 

Might have to watch for freezing drizzle too in some spots if ice crystal production shuts off in the clouds....which can happen if things become too much in the low levels.

Will, does that extend south of VT to GC?  Thanks for the mby answer.

[ORH_wxman]

2 minutes ago, Damage In Tolland said:

Nothing south of 90?

There is some south, but it looked like best LL convergence was north...but down there it would still probably be whitened up.

[OceanStWx]

12 minutes ago, ORH_wxman said:

Euro looks like it actually has a bit of weenie LL convergence for T-day north of the pike and into CNE. Could be a light snow most of the day for areas like N ORH county and into a good chunk of VT/NH. It almost looks like a BDF as you head toward night...the high starts imposing a bit more NE flow.

 

Might have to watch for freezing drizzle too in some spots if ice crystal production shuts off in the clouds....which can happen if things become too much in the low levels.

That's my only concern for something other than rain or snow. The mid levels are cooperating with temps to make it a boundary layer driven liquid versus frozen. But if we lose saturation in the DGZ, that could make things ugly.

[CoastalWx]

17 minutes ago, ORH_wxman said:

Euro looks like it actually has a bit of weenie LL convergence for T-day north of the pike and into CNE. Could be a light snow most of the day for areas like N ORH county and into a good chunk of VT/NH. It almost looks like a BDF as you head toward night...the high starts imposing a bit more NE flow.

 

Might have to watch for freezing drizzle too in some spots if ice crystal production shuts off in the clouds....which can happen if things become too much in the low levels.

The 4KM NAM has almost a mini CF near BOS and NE MA too. I was thinking it may be enough for some near 32F air hanging a bit further S and E then some globals show. You can see the nrly drain vs NE winds on the S Shore.

[ORH_wxman]

1 minute ago, OceanStWx said:

That's my only concern for something other than rain or snow. The mid levels are cooperating with temps to make it a boundary layer driven liquid versus frozen. But if we lose saturation in the DGZ, that could make things ugly.

 

I've seen this type of setup too on the Euro a bunch of times....the high starts pressing down a bit as the weak sfc wave approaches from the WSW, and typically you get:

1. Models warm the BL too much over the interior...classic case of guidance going 34F and it turns into 29-30F.

2. An orographically favored location could over perform a bit and/or also get hours of rotting freezing drizzle or light snow/snow grains when precip has shut off most everywhere else (this could be an issue more into Friday morning).

 

 

We'll see as we get closer (RGEM will likely be helpful in another couple runs)...but that high getting "Tugged" southwest a bit by the approaching wave always sets off alarms in my head for mini-busts that could have a decent impact for holiday travel. We all know it doesn't take much FZDZ to screw things up.

 

[OceanStWx]

5 minutes ago, ORH_wxman said:

I've seen this type of setup too on the Euro a bunch of times....the high starts pressing down a bit as the weak sfc wave approaches from the WSW, and typically you get:

1. Models warm the BL too much over the interior...classic case of guidance going 34F and it turns into 29-30F.

2. An orographically favored location could over perform a bit and/or also get hours of rotting freezing drizzle or light snow/snow grains when precip has shut off most everywhere else (this could be an issue more into Friday morning).

 

 

We'll see as we get closer (RGEM will likely be helpful in another couple runs)...but that high getting "Tugged" southwest a bit by the approaching wave always sets off alarms in my head for mini-busts that could have a decent impact for holiday travel. We all know it doesn't take much FZDZ to screw things up.

NAM Bufkit is pretty bullish for our interior already. 1-2" throughout most of NH. 

[ORH_wxman]

18z NAM is cooling things off for Tday...not a total shock given the discussion above when the Euro came out. Looks like even right into BOS would get a burst of light snow...at least away from immediate water. It even keeps areas like BED around freezing during the afternoon with that NE/NNE flow locking in the source cold from Maine.

[CoastalWx]

Tucky tucky. A few weeks later and it would be pretty dam slippery all day in many spots. Probably already will be inland and higher spots near ORH hills.

[ORH_wxman]

7 minutes ago, CoastalWx said:

Tucky tucky. A few weeks later and it would be pretty dam slippery all day in many spots. Probably already will be inland and higher spots near ORH hills.

I'll be up in Princeton on T-day and on Winter Hill later afternoon/evening...should be interesting driving around the area.

[OceanStWx]

17 minutes ago, ORH_wxman said:

18z NAM is cooling things off for Tday...not a total shock given the discussion above when the Euro came out. Looks like even right into BOS would get a burst of light snow...at least away from immediate water. It even keeps areas like BED around freezing during the afternoon with that NE/NNE flow locking in the source cold from Maine.

 

7 minutes ago, CoastalWx said:

Tucky tucky. A few weeks later and it would be pretty dam slippery all day in many spots. Probably already will be inland and higher spots near ORH hills.

BOX petitioned WPC to add some 0.01" ice to their forecast for Thursday night. I tossed in my support for it too, since it's definitely appearing to be a cooler scenario.

What was scary is that the GFS still factors into boundary layer forecast questions though.

[ORH_wxman]

1 minute ago, OceanStWx said:

 

BOX petitioned WPC to add some 0.01" ice to their forecast for Thursday night. I tossed in my support for it too, since it's definitely appearing to be a cooler scenario.

What was scary is that the GFS still factors into boundary layer forecast questions though.

They are clearly not following one the Ten Commandments of Weather Forecasting....

 

"Thou shalt not ever use the GFS for boundary layer temperatures"

[40/70 Benchmark]

Love me some tuckey

[OceanStWx]

1 minute ago, ORH_wxman said:

They are clearly not following one the Ten Commandments of Weather Forecasting....

 

"Thou shalt not ever use the GFS for boundary layer temperatures"

Main source of input for the National Blend of Models...

But that's what human forecasters are for.

The isentropic charts off the GFS anyway as definitely decent for WNE. Some 30 kts of sloped ascent through the mid levels before it washes out east of ORH or so. It still looks like snow east of there, but I think that southern VT, SW NH, N central MA area could see a nicer burst.

[ORH_wxman]

17 minutes ago, OceanStWx said:

Main source of input for the National Blend of Models...

But that's what human forecasters are for.

The isentropic charts off the GFS anyway as definitely decent for WNE. Some 30 kts of sloped ascent through the mid levels before it washes out east of ORH or so. It still looks like snow east of there, but I think that southern VT, SW NH, N central MA area could see a nicer burst.

 

Yeah I envision a band in the morning that is most potent to the west and weakening as it heads east...and then during midday/afternoon the "event" transitions from a mid-level burst to more low-level stuff....this where FZDZ could start being a problem, although for a while, we still have saturation pretty far up so we will likely just get small flakes for a time via seeder-feeder. Overnight though and into Friday morning, you can see the dry air working down to around 800mb, so that's def when I'd be worried about FZDZ for ORH and up into Monads (I didn't look further northeast toward your area, but it is probably a similar sounding by 12z Fri)

[Damage In Tolland]

33 minutes ago, CoastalWx said:

Tucky tucky. A few weeks later and it would be pretty dam slippery all day in many spots. Probably already will be inland and higher spots near ORH hills.

We slip

[OceanStWx]

2 minutes ago, ORH_wxman said:

Yeah I envision a band in the morning that is most potent to the west and weakening as it heads east...and then during midday/afternoon the "event" transitions from a mid-level burst to more low-level stuff....this where FZDZ could start being a problem, although for a while, we still have saturation pretty far up so we will likely just get small flakes for a time via seeder-feeder. Overnight though and into Friday morning, you can see the dry air working down to around 800mb, so that's def when I'd be worried about FZDZ for ORH and up into Monads (I didn't look further northeast toward your area, but it is probably similar sounding by 12z Fri)

I'm hoping for more of the snow grains style of unsaturated DGZ, but you usually need colder temps aloft for that. 

I think most of ME will be okay, it looks like we hang onto enough mid level RH to avoid going completely dry. S NH is a different story though.

[ORH_wxman]

Just now, OceanStWx said:

I'm hoping for more of the snow grains style of unsaturated DGZ, but you usually need colder temps aloft for that. 

I think most of ME will be okay, it looks like we hang onto enough mid level RH to avoid going completely dry. S NH is a different story though.

I usually get surprised at how "warm" the sounding can get and still support snow. Usually you need like warmer than -5C in the saturated zone even though textbooks tell you -7 or -8 is the limit...but our salt nuclei/marine influence in New England seems to allow us to go warmer than what you'd find in the plains or some place similar.

[OceanStWx]

5 minutes ago, ORH_wxman said:

I usually get surprised at how "warm" the sounding can get and still support snow. Usually you need like warmer than -5C in the saturated zone even though textbooks tell you -7 or -8 is the limit...but our salt nuclei/marine influence in New England seems to allow us to go warmer than what you'd find in the plains or some place similar.

It's true, sea salt does wonders.

[40/70 Benchmark]

Has 32.000000001 rain written all over it here.

[Sugarloaf1989]

NWS has freezing rain in the forecast here from Thursday into Friday. This part of Enfield ices up easily, I guess the CRV locks in the low level cold.

[ORH_wxman]

18z GFS is a little different....it has the initial band, but further north....mostly Rt 2 northward. But then it keeps the system a little more organized as it heads east and a 2nd round of lift comes through late afternoon/evening and produces some steady light snow for the rest of interior SNE north of about HFD-SFZ.

[OceanStWx]

2 minutes ago, ORH_wxman said:

18z GFS is a little different....it has the initial band, but further north....mostly Rt 2 northward. But then it keeps the system a little more organized as it heads east and a 2nd round of lift comes through late afternoon/evening and produces some steady light snow for the rest of interior SNE north of about HFD-SFZ.

A big difference is that the GFS doesn't really have a "break" while the Euro you could find a stopping point for round 1.

[Ginx snewx]

4 minutes ago, ORH_wxman said:

18z GFS is a little different....it has the initial band, but further north....mostly Rt 2 northward. But then it keeps the system a little more organized as it heads east and a 2nd round of lift comes through late afternoon/evening and produces some steady light snow for the rest of interior SNE north of about HFD-SFZ.

Taking your earlier statements about the GFS BL, nice

[ORH_wxman]

2 minutes ago, Ginx snewx said:

Taking your earlier statements about the GFS BL, nice

Yeah the 18z GFS is actually rain verbatim for ORH later on T-day....we toss.

Everything else on the model would imply snow though...so it's fine as long as we toss BL temps.

[Ginx snewx]

RGEM being bone dry is a concern but its early for the RGEM. I could see that happening south of Rt 2

[ORH_wxman]

3 minutes ago, Ginx snewx said:

RGEM being bone dry is a concern but its early for the RGEM. I could see that happening south of Rt 2

 

We'll see how tonight's run is and especially tomorrow's 12z run. I feel like this event has been slowing down slightly too on guidance...earlier runs were bringing stuff in more toward 12z and now we're like 15z.  

[OceanStWx]

7 minutes ago, ORH_wxman said:

Yeah the 18z GFS is actually rain verbatim for ORH later on T-day....we toss.

Everything else on the model would imply snow though...so it's fine as long as we toss BL temps.

I mean it's funny that we just shorthand it as if it's understood that we're only considering temps aloft and tossing the boundary layer with that model.