1/27-28: Possible Significant Accumulations in N. MA & N

[donsutherland1]

Although New England and to some extent the northern part of the Mid-Atlantic region is likely to miss out on most if not all of the snow associated with a system that brought snows into parts of North Carolina and Virginia earlier today, another system is likely to give much of this region a significant snowfall late Tuesday into Wednesday.

For starters, it should be noted that three of the major snowstorms cited in Kocin's and Uccellini's <i>Snowstorms Along the Northeastern Coast of the United States</i> had secondary development somewhere over South Carolina or just off the South Carolina coast:

- March 2-5, 1960
- December 10-13, 1960
- February 2-5, 1961

<b>Important:</b> The point here is not that this emerging system will mimic these noteworthy storms but that Miller B systems with secondary development in the vicinity of SC can become significant and sometimes major East Coast snowstorms.

If one examines the upper air patterns, one finds some similarities to the setup that preceded the December 29, 1976 snowstorm that buried Boston under nearly a foot of snow but brought just 2" to NYC.

Before those in the northern NJ and southeastern NY region get up in arms, it is important to point out that there are significant differences, as well, particularly the likely Miller B evolution.

Considering these similarities and differences, one can reasonably sketch out a possible area for significant snows (6" or more):

<b>Low Probability: </b>
Baltimore, Philadelphia, Wilmington, DE

<b>Moderate Probability: </b>
Trenton, Newark, New York City

<b>High Probability:</b>
Boston, Concord, Hartford, Providence, White Plains, Worcester

The January 25, 2004 12Z run of the ECMWF holds out even greater hope for Philadelphia than is implied above. The following are 850 mb temperatures, 850 mb relative humidity, and 700 mb relative humidity for select cities:

<b>Baltimore: </b>
Tuesday +1C 99% 58%
Wednesday -9C 90% 79%

<b>Boston: </b>
Tuesday -5C 86% 92%
Wednesday -9C 93% 97%

<b>New York City:</b>
Tuesday -2C 86% 92%
Wednesday -7C 97% 87%

<b>Philadelphia:</b>
Tuesday -1C 100% 81%
Wednesday -8C 95% 96%

At this stage, I anticipate rapid secondary development just off the South Carolina coast beginning Tuesday morning along a front sitting in the region, as a strong primary system moves into eastern Illinois.

Given the strong blocking courtesy of a 50-50 low and 1035 to 1040 mb high pressure centered over Quebec, I believe some degree of confluence will preclude the primary system from reaching 999 mb as depicted on the ECMWF (1000 mb to 1002 mb is a better bet in my opinion meaning somewhat less warming ahead of the main event later Tuesday into Wednesday). Speaking of trends, the 999 mb estimate for the primary system is weaker than that shown yesterday.

Equally important, I believe the system will be forced eastward, helping accelerate the transfer of energy to the developing secondary system. Thus, I expect it to be somewhat stronger than the 991 mb shown on the ECMWF (1/28 12Z)--perhaps on the order of 985 mb to 990 mb.

Thus, to sketch a track, I would anticipate that it would pass somewhat closer to the Coast than shown on the European Model given its somewhat greater strengthening.

All said, I expect it to pass within 100-150 miles of Myrtle Beach, Cape May, Montauk Point, and Cape Cod. The most explosive deepening phase should occur on between Cape May and Montauk Point with some deepening as it passes Cape Cod.

This is a first cut at the system and all ideas are preliminary on what is a complex situation. Early numbers at this point:

Boston: 10"-16"
New York City: 6"-10"
Newark: 4"-8"
Philadelphia: 2"-4" perhaps up to 6"
Providence: 8"-14"
White Plains: 6"-12"
Worcester: 14"-20"

The further south one goes, the greater degree of caution is required. Nevertheless, given the European Model's high relative humidities for Philadelphia, I believe the figures I offer are reasonable at this time.

Later model data should help bring clarity to the situation. Nevertheless, refinements notwithstanding, a significant to potentially major snowstorm is likely to affect the northern Mid-Atlantic and New England regions.

[Colin]

What about Allentown, Don?

[FLguy]

nice post don. i also think that most of E PA/NJ/and NYC will get into a period of significant CSI banding which could push those totals up.

[Chris the Weather Man]

I think, NYC will get more, like 12-15 inches.. Don,Great Post.....

[WoodstockWX]

excellent forecast and discussion/analysis Don, your snowfall totals seem very likely and are similar to what I'm thinking.

[donsutherland1]

Colin,

I'm thinking that Allentown has a good chance at seeing more than six inches.

[Colin]

Sweet...thanks Don!

[Stormsfury]

Awesome discussion as usual, Don ...

SF

[donsutherland1]

Excellent point, FLguy. I'm being conservative for now on this. If everything comes together (banding and development of the 2ndary), I could envision NE PA, N NJ, and SE NY all seeing the possibility of a foot or perhaps somewhat more.

[FLguy]

I think, NYC will get more, like 12-15 inches.. Don,Great Post.....

if my banding theory works out.

[donsutherland1]

Thanks SF and Quincy.

Did parts of SC receive any freezing rain today?

[R0bb0871]

What about Northwest Jersey? Morris County. Thanks!

[donsutherland1]

Chris,

The potential does exist for more. I'll wait until tomorrow's run of the models for refinements. Needless to say, if I bust, I always hope that there is more snow than I anticipated rather than less.

Keep in mind the possibilities of a Gulf of Mexico Storm possibly just after the next weekend.

Of course, even after the late Tuesday into Wednesday snowstorm, I still believe that February will likely see above to much above normal snowfall in the Mid-Atlantic and Northeast, with a strong possibility of a major snowstorm (12" or more).

[FLguy]

Excellent point, FLguy. I'm being conservative for now on this. If everything comes together (banding and development of the 2ndary), I could envision NE PA, N NJ, and SE NY all seeing the possibility of a foot or perhaps somewhat more.

thanks.

i saw the same thing occur with the early FEB 2001 nor'easter (with respect to CSI bands and mixed precipitation.) it caused my forecasted totals to be underdone by as much as 10 inches across northern new jersey. some areas eventually ended up with 18"+ in some portions of sussex county.

[donsutherland1]

R0bb0871,

At this point in time, I believe Morris County will see 6"-12".

[FLguy]

Chris,

The potential does exist for more. I'll wait until tomorrow's run of the models for refinements. Needless to say, if I bust, I always hope that there is more snow than I anticipated rather than less.

Keep in mind the possibilities of a Gulf of Mexico Storm possibly just after the next weekend.

Of course, even after the late Tuesday into Wednesday snowstorm, I still believe that February will likely see above to much above normal snowfall in the Mid-Atlantic and Northeast, with a strong possibility of a major snowstorm (12" or more).

exactly and at least one or perhaps two major events somewhere in the eastern part of the country.

[Dj3]

Great discussion don! Do you think pittsburgh will see any snow from this system before its energy goes to the coast?

[FLguy]

Great discussion don! Do you think pittsburgh will see any snow from this system before its energy goes to the coast?

sure as the transfer takes place the column will be forced to rapidly cool which would turn any precip over to snow. there is the potential for significant accumulations.

[Chris the Weather Man]

Excellent point, FLguy. I'm being conservative for now on this. If everything comes together (banding and development of the 2ndary), I could envision NE PA, N NJ, and SE NY all seeing the possibility of a foot or perhaps somewhat more.

thanks.

i saw the same thing occur with the early FEB 2001 nor'easter (with respect to CSI bands and mixed precipitation.) it caused my forecasted totals to be underdone by as much as 10 inches across northern new jersey. some areas eventually ended up with 18"+ in some portions of sussex county.

Yes, I remember that, It dumped 19 inches in Oxford NJ... High Point got 18.5 inches....

[Dj3]

THanks flguy! Does significant mean more than 4". What do you think of the first guess map from wxrisk. It has pittsburgh in the ice storm zone