The 12/15-16/2007 Snowfall: Initial Thoughts

[donsutherland1]

After teasing many East Coast snow geese with prospects of a major snowstorm for several runs, the computer guidance shifted to a consensus that favors a major interior snowstorm. It appears reasonably likely that a strong primary cyclone will track into the Ohio Valley while a secondary system forms probably somewhere in the vicinity of North Carolina and then tracks across the Delmarva into or just off eastern New England. As a result, a strong push of warmer air will likely surge northward. Hence, assuming the present model consensus is reasonably accurate, such cities as Washington, Baltimore, Philadelphia, New York, and probably Boston, will witness mainly a wind-driven rain from the upcoming storm. Nevertheless, some accumulating snow is likely in New York City, Providence, and especially in Boston. Philadelphia could also start off with snow or sleet. Boston could actually receive accumulations at the onset of the storm and afterward as the storm departs.

There are some disagreements and the solution is not yet fully certain. The NAM is perhaps offering the coldest solution to eastern New England. If the 12/14 0z run of the NAM is right, Boston could again be in line for a significant snowfall. The GFS suggests a more modest snowfall.

One system that had some similarities to what might be likely with the upcoming event was one that affected the eastern United States on February 17-18, 1952. A primary system moved into the Ohio Valley and a secondary system developed and moved northward along the East Coast. This storm provided heavy snows to interior portions of New York State and New England. Snowfall amounts for select cities were as follows:

Albany: 12.6"
Binghamton: 7.3"
Boston: 3.3"
Burlington: 12.3"
Caribou: 10.1"
New York City: 2.1"
Philadelphia: None
Washington, DC (DCA): None

Leaning toward the GFS and ECMWF solutions, considering past experience with secondary storms crossing the Delmarva, and taking into consideration the 1952 analog, my initial thinking for the upcoming event is as follows:

High Risk of 4" or more; Moderate Risk of 8" or More:
Albany, Concord, Portland, Scranton, Worcester

High Risk of 8" or more; Moderate Risk of 12" or More:
Bangor, Binghamton, Burlington, Caribou, Syracuse

[btangy]

This storm reminds me of the Valentine's Day storm we had earlier in the year. Similar setup with a coastal runner and heavy precipitation amounts. The one thing different about this system is that there will be a strong ridge to the N and some very cold air locked in place at low levels along with the antecedent snow cover from the recent storm. I'm a bit wary that the models are not handling this correctly. As the NWS discussion from Taunton said earlier, it's unusual to get an inland storm with such cold air in place, but the model consensus has been great for several days and now with the trough over the west coast being sampled by the radiosonde network, it increases confidence in the handling of this system. On the other hand, most of the ensemble members are showing a more offshore solution and have been consistently showing this as well. More weight has to be given to the operational models, but I expect the secondary development to take over rapidly and track over or near Cape Cod instead of further inland.

Even with the NAM showing a seemingly warm solution, it has so much cold air locked in place that it takes quite awhile for the wind off the ocean to erode it completely. Could be looking at some hefty sleet and ice amounts over a large region before any changeover to rain and then a flash freeze afterwards causing some really treacherous icy conditions.

[cpdaman]

a track over the cape would certainly lead to the always intresting "coastal front" set up

where rain usually takes over at the height of the storm from providence to boston and SE with a mix between 95 and 495 and then snow outside of there, but obviously their is still alot of uncertainty even 48 hours out. Stay tuned! I heard one of TWC mets saying a certain model takes this storm to 968 MB.

[Coredesat]

Any idea how much rain the Richmond area would be looking at?

[Fodie77]

What are your thoughts for Winchester and the Shenandoah Valley over the weekend? I'd appreciate any info. you could give me as I'll be heading home there from Virginia Tech on Saturday or Sunday. Thanks!

[cpdaman]

from the various Disco' i understand mid level warming is a big issue w/ the forecast.
what is the confidence level in the upper low/original low's track (not the secondary coastal low)
possibly a major sleet storm? IMO sleet is the least harmless of all the frozen precip types, it doesn't pile up much, and isn't pure skating ice like freezin rain ( not saying it is a walk in the park but..)

[terstorm1012]

from the various Disco' i understand mid level warming is a big issue w/ the forecast.
what is the confidence level in the upper low/original low's track (not the secondary coastal low)
possibly a major sleet storm? IMO sleet is the least harmless of all the frozen precip types, it doesn't pile up much, and isn't pure skating ice like freezin rain ( not saying it is a walk in the park but..)

That's what they thought on Valentine's Day, and most of Eastern/Northeastern PA's state and interstate network was paralyzed for days because of it.

However, that was about 15 hours straight of sleet---this storm won't last that long.

[tolakram]

Howdy,

I'm in Cincinnati and it appears the track of the low, which will be near CVG, is going to be critical as to how much snow we get vs rain. Any thoughts on snowfall amounts for us in the Ohio Valley? Thanks.

- Mark

[donsutherland1]

So far, it has been good to be a Canadian and New England snow goose in the opening of Winter 2007-08. To quote Miley Cyrus (the Board has a growing number of younger snow geese, so why not quote someone younger this time around?), these snow geese might well be singing “I’ve got everything I’ve always wanted” as far as snowfall is concerned. A look at select cities in this region, shows a much snowier start to the winter.

2007 vs. 2006 snowfall to date:

Boston: 11.6” vs. 0.4”
Burlington: 19.9” vs. 6.2”
Caribou: 37.4” vs. 7.0”
Montreal*: 28.9” (73.4 cm) vs. 3.9” (9.8 cm)
Ottawa: 109.2 cm (43.0 cm) vs. 5.0” (12.6 cm)
Toronto*: 10.5” (26.6 cm) vs. 0.2” (0.6 cm)

* Through December 12

With the model guidance showing the potential for another blockbuster snowstorm in parts of that area, they are truly “living the dream.” Even Mid-Atlantic snow geese received an early feeding courtesy of a clipper that blossomed into a moderate snow-producer. To borrow quote Jerry (Weathafella), long live winter!

Based on the latest guidance, with an emphasis toward the ECMWF and GFS, I continue to believe that this event will be a classic interior snowstorm. Along the coast, warmer air will quickly punch northward. Sleet could even prove an unwelcome visitor in Albany and Binghamton. The strong primary system should also permit a significant snowfall for cities such as Cleveland, Detroit, and Toronto.

My initial estimates are as follows:

Albany: 7”-14”
Allentown: 1”-3”
Bangor: 6”-12”
Boston: 3”-6”
Burlington: 10”-16”
Caribou: 10”-16”
Cleveland: 5”-10”
Concord: 5”-10”
Detroit: 5”-10”
New York City: <1”
Newark: <1”
Montreal: 7”-14” (17.8 cm-35.6 cm)
Ottawa: 5”-10” (12.7 cm-25.4 cm)
Pittsburgh: 2”-4”
Portland: 5”-10”
Poughkeepsie: 2”-4”
Providence: 1”-3”
Scranton: 3”-6”
Syracuse: 12”-18”
Toronto: 7”-14” (17.8 cm-35.6 cm)
Worcester: 3”-6”

[tropicana]

this is gonna be a big one it seems for Toronto, even paralyzing! woooo

[Cyclenall]

Yay, another weekend snowstorm that is happening at the exact time the last one hit two weeks ago.

[Nimbus]

All the models are pulling subtropical moisture up and building a strong coastal storm. NOGAPS and NAM keep the track far enough offshore to bring Blizzard conditions as far south as Portland/Boston but GFS is still further inland. This storm is a real challenge to forecast for the big coastal New England citys. A track 50 miles either way means a blizzard becomes an ice storm and vice versa. Cold air at the surface means lots of ice build up if the storm takes the GFS track almost be better to have a blizzard.

[tropicana]

Yay, another weekend snowstorm that is happening at the exact time the last one hit two weeks ago.

i know cycle! The last *nice* sunday around here... Sunday nov 25. Sundays arent having much luck if you dont like snow around here.

[Stephanie]

Well, if we're going to have a big storm during the winter (or almost) and it's too warm for snow, I'll GLADLY take the rain. Ice scares the crap out of me.

Those ski resorts in New England are really having a great season so far!

[Category 5]

I usually don't expect to see a major winter storm in December around here anymore these days.

[donsutherland1]

Based on the latest computer guidance, which is coming into better agreement over southern New England, I have made a few changes to my estimates for the storm that will be impacting parts of the Great Lakes region, Northeast, and southern Canada in the 12/15-17 timeframe. Eastern Ontario and across southern Quebec, along with Upstate New York and portions of northern New England could be hammered by a crippling snowfall.

My snowfall estimates are as follows:

Albany: 7”-14”
Allentown: 1”-3”
Bangor: 5”-10”
Boston: 3”-6”
Burlington: 10”-16”
Caribou: 10”-16”
Cleveland: 6”-12”
Concord: 5”-10”
Detroit: 6”-12”
Hartford: 2"-4"
New York City: <1”
Newark: <1”
Montreal: 12”-18” (30.5 cm-45.7 cm)
Ottawa: 7”-14” (17.8 cm-35.6 cm)
Pittsburgh: 2”-4”
Portland: 5”-10”
Poughkeepsie: 2”-4”
Providence: 1”-3”
Scranton: 1”-3”
Syracuse: 12”-18”
Toronto: 7”-14” (17.8 cm-35.6 cm)
Worcester: 3”-6”

[tolakram]

We got an unexpected shot of heavy snow here in Cincinnati, 2+ inches on the ground from heavy snow in the last 2 hours, temps hovering right at 30F. NWS has bumped snow totals from 1 inch to now 2 - 4 inches prior to changeover to rain this afternoon.

[Stephanie]

I usually don't expect to see a major winter storm in December around here anymore these days.

It is rare, but we also haven't been this close to having big snows in December for a while. Actually, we not really get much snow in December at all. We have seen a lot of winter weather for the month of December this year.

[tolakram]

Turned to sleet / freezing rain around 10:30am ... got enough snow for the kids to sled, and now the ice is making for a faster run.

[Cyclenall]

It looks like another Wikipedia article is in order . THis is going to be extreme for Toronto and TWN is calling for 38 cm by Sunday evening for them. What is Buffalo NY going to get?

EDIT: All of southern Ontario is under a winter storm now as of 3:44 pm EST.