December 27/28 Storm Threat

[CT Rain]

It's interesting see how the NAM handled the low levels with this type of track being to the south and over Long Island. It really shows you how latitude will help in this case and why in general people in CT/RI/SE Mass tie nooses with a track over Long Island as opposed to SE of KBID.

[mahk_webstah]

We ran out of panels, The s/w was south of here @hr 84

so snh is already past the 1.25 qpf and it is still sw of us??! wow

[Damage In Tolland]

I don't see how Kevin will be 41 with that track.

Yeah low maybe mid 30's for now colder with another tickle SE

[OceanStWx]

GFS fgen (clockwise from top left H5, H7, H9, H8). You can see that it really pegs the lower level fgen to be near the coast (hence QPF bomb there), while the mid level banding would be west of the mountains (where the second QPF max is located).

Some resolution issues here, but had to drop down to 12km to get to 84 hours. This is 6 hours later, but roughly the same relative position of the surface low. The NAM12 has the same idea of strong fgen near the coast (with strong fgen along the east slopes of the mountains at H9). But it also has a band of fgen running from near BTV to near PWM. Definitely more collocated than the GFS.

[CT Rain]

This is looking awesome for a lot of folks. 12z NAM is just awesome up this way, and you guys still look to get like 6-12" before any change over...you may be completely dry slotted by the time temps come near freezing if they do at all.

Big northeast winter storm en route.

The tilted look to the low/mid/upper levels definitely is like Valentines Day 2007 in a way... where the track is perfect for SNE snows in some cases (the sfc that is) but the best snows could be more like ALB-Berks-CNE/NNE.

I dunno the sfc low track is awfully far NW for a lartge portion of SNE outside of N Mass and the Berkshires.

Huge gradient along the Pike probably.

[Sugarloaf1989]

I don't see how Kevin will be 41 with that track.

Which Kevin?

[dryslot]

so snh is already past the 1.25 qpf and it is still sw of us??! wow

The heavier rates were right over that area at the end of the run

[Quincy]

Dec 25-26, 2002 keeps coming up as a top analog:

[dryslot]

GFS fgen (clockwise from top left H5, H7, H9, H8). You can see that it really pegs the lower level fgen to be near the coast (hence QPF bomb there), while the mid level banding would be west of the mountains (where the second QPF max is located).

Some resolution issues here, but had to drop down to 12km to get to 84 hours. This is 6 hours later, but roughly the same relative position of the surface low. The NAM12 has the same idea of strong fgen near the coast (with strong fgen along the east slopes of the mountains at H9). But it also has a band of fgen running from near BTV to near PWM. Definitely more collocated than the GFS.

like

[weatherMA]

While not that great for SNE...the fact that the srefs have a 30% already for anywhere for 12+ snow is very impressive at 60 hours out....hopefully this SE trend can continue just a little bit longer...

[HIPPYVALLEY]

I dunno the sfc low track is awfully far NW for a lartge portion of SNE outside of N Mass and the Berkshires.

Huge gradient along the Pike probably.

This storm is a great example of how NW MA from Gardner to N. Adams really should be considered CNE when discussing probable outcomes, snow totals etc. Otherwise there is huge conrtrasts in what "SNE" posters are experiencing/observing.

[Cold Miser]

This storm is a great example of how NW MA from Gardner to N. Adams really should be considered CNE when discussing probable outcomes, snow totals etc. Otherwise there is huge conrtrasts in what "SNE" posters are experiencing/observing.

I've always thought that higher elevations in Tolland, CT should be considered NNE.

[CT Rain]

This storm is a great example of how NW MA from Gardner to N. Adams really should be considered CNE when discussing probable outcomes, snow totals etc. Otherwise there is huge conrtrasts in what "SNE" posters are experiencing/observing.

Yeah I could see a scenario where N CT has a tough time picking up more than 2 or 3" meanwhile once you're north of Northampton someone is getting a foot without much of a challenge.

[ORH_wxman]

This storm is a great example of how NW MA from Gardner to N. Adams really should be considered CNE when discussing probable outcomes, snow totals etc. Otherwise there is huge conrtrasts in what "SNE" posters are experiencing/observing.

Using phrases like N of the pike or Rt 2 clears confusion.

[OceanStWx]

While not that great for SNE...the fact that the srefs have a 30% already for anywhere for 12+ snow is very impressive at 60 hours out....hopefully this SE trend can continue just a little bit longer...

I wonder if those are being affected by the issues going on with the ARW members. Essentially, there is a problem with incorrectly not assigning pytpe to frozen or freezing precip. And the ARW members are dragging down the means of snowfall and rates (ZR too). If that's the case, these probs would probably be even higher if it weren't for the low balled totals from the ARW runs.

[40/70 Benchmark]

I think your area (and probably mine considering I'm only about 12 miles SSE of you) is almost a lock for mostly/all frozen...just a matter of how much is going to be IP/ZR versus snow. We may try and tick to 34-35F near the end, but we'd probably be long since dryslotted at that point.

Unless we see a notable shift back NW in guidance for the sfc low tracks, its going to stay cold at the sfc in our neck of the woods and certainly up through interior CNE.

This is the type of scenario in which I'll grab several inches of snow, then rot in the upper 30's for hours......like a 12/16/07 lite.

[Quincy]

Liking the look of the 850mb low track from the 12z NAM. Takes it from DCA-ACY-south of ACK.

[weatherMA]

This is way too close for my liking lol. Let's try and move this 50-75 miles SE. I could see getting 3" or 10" of the NAM is right....it looks like by 12z Tuesday its sleeting up to route 2 with a warm layer around 830?

[OceanStWx]

I wonder if those are being affected by the issues going on with the ARW members. Essentially, there is a problem with incorrectly not assigning pytpe to frozen or freezing precip. And the ARW members are dragging down the means of snowfall and rates (ZR too). If that's the case, these probs would probably be even higher if it weren't for the low balled totals from the ARW runs.

When you look at the mean snowfall from the plumes, that's a difference between 7" by the end of the run at GFL and 11.5" when you omit the ARW members.

[40/70 Benchmark]

The boundary layer is really going to cook me I think...mid levels won't be a huge issue, as opposed to s of the pike.

[dendrite]

I wonder if those are being affected by the issues going on with the ARW members. Essentially, there is a problem with incorrectly not assigning pytpe to frozen or freezing precip. And the ARW members are dragging down the means of snowfall and rates (ZR too). If that's the case, these probs would probably be even higher if it weren't for the low balled totals from the ARW runs.

Good call.

[CT Rain]

Liking the look of the 850mb low track from the 12z NAM. Takes it from DCA-ACY-south of ACK.

The typical mid level low rules don't really apply here. The mid level centers are quite occluded and the best frontogenesis is displaced way north of their track.

[ORH_wxman]

When you look at the mean snowfall from the plumes, that's a difference between 7" by the end of the run at GFL and 11.5" when you omit the ARW members.

I wonder if they are doing it for the 12/25 system too. I noticed the probs seemed awfully low considering there was plenty of QPF and we certainly weren't in any danger of BL or mid-level taint issues.

[weatherMA]

I wonder if those are being affected by the issues going on with the ARW members. Essentially, there is a problem with incorrectly not assigning pytpe to frozen or freezing precip. And the ARW members are dragging down the means of snowfall and rates (ZR too). If that's the case, these probs would probably be even higher if it weren't for the low balled totals from the ARW runs.

Interesting. They did seem a little low for SNE as at a minimum I expect a few inches front end here.

[40/70 Benchmark]

I wonder if they are doing it for the 12/25 system too. I noticed the probs seemed awfully low considering there was plenty of QPF and we certainly weren't in any danger of BL or mid-level taint issues.

Kev and I may get pretty similar amount of snow....with the mid levels serving as the largest impediment there, and the BL here.

[ORH_wxman]

12z GFS at 54h looks a bit SE of 60h at 06z with both the UL and sfc features...we'll see if that holds further into the run.

[Quincy]

66hr GFS is a touch cooler. 0C line at 850 still south of all of SNE except ACK, MVY and the extreme SW tip of CT. Over 0.5" QPF for CT.

[ineedsnow]

wow what a good thump on the 12z gfs

[Quincy]

72hr GFS: 0C line barely makes it to the Pike as the heaviest precipitation is pretty much done.

[OceanStWx]

I wonder if they are doing it for the 12/25 system too. I noticed the probs seemed awfully low considering there was plenty of QPF and we certainly weren't in any danger of BL or mid-level taint issues.

They almost assuredly are. I don't think I fix is planned until next month according to the note on the SPC SREF site.