2/13-14/2007 Storm: My Snowfall Estimates

[donsutherland1]

In the options trading market, one finds that American options (those that be exercised e.g., converted to stock, at any time prior to expiration) the market value generally exceeds the intrinsic value. This premium represents, in part, the value that is placed on time. In other words, there is a perceived value of waiting. The same can hold true with forecasting. As the model runs roll in, rather than lurching wildly from one run to another, there is value in maintaining a degree of continuity and slowly adjusting toward the changes in the modeling. This gives the forecaster time to avoid extreme swings e.g., from heavy snow to heavy rain and then back again, based on each new model run. Such an approach can build a measure of confidence, especially as it allows for the models to work toward a consensus.

After waiting through yesterday into this afternoon, I am now reasonably confident that even as there remain some sizable differences in the modeling, one will likely see a primary system track toward eastern Kentucky or West Virginia where it will fade and secondary system develop somewhere near the South Carolina/North Carolina border and then track northeastward from there. Unfortunately, the combination of the primary low and position of the 850 mb low suggests that a wedge of warm air will sweep northward. The warm tongue will be deep enough so that it cannot be overcome by the storm’s dynamics. As a result, the coastal plain and cities outside of those in northern New England or western New York State are likely to see a change to sleet, freezing rain, or rain.

Unfortunately, in many of these cities, the snowfall will be much less than what I had thought was possible late last week e.g., I had thought the DCA-BWI-HGR-PHL area would likely see more than 6” with a foot or more possible.

It should be noted that the 18z run of the NAM is coming in colder than the 12z run. While this won’t significantly alter the outcome for the coastal plain, it could suggest the emerging potential for a longer period of snow, particularly for interior sections that might otherwise transition sooner.

Comparisons of forecast 850 mb temperatures for select cities follow:



At this time, my initial snowfall estimates are as follows:

Albany: 12”-18”
Allentown: 2”-4”
Baltimore: 2” or less
Binghamton: 8”-16”
Boston: 3”-7”
Burlington: 16”-24”
Harrisburg: 3”-6”
Hartford: 4”-8”
New York City: 1”-3”
Newark: 1”-3”
Philadelphia: 1”-3”
Providence: 2”-5”
Syracuse: 14”-20”
Washington, DC: DCA: 2” or less; IAD: 2” or less
Watertown: 8”-16”
Worcester: 5”-10”

[angelwing]

Thank you Don! Kinda interesting, the city was already putting brine down on State road about 20 mins ago, first time I've seen them put it down so early.

[Coredesat]

Interesting discussion, even though I don't really like the outcome. It looks like just another dud storm for Richmond.

[Category 5]

Are the flurries coming toward us now related to the main storm?

[Stephanie]

They're probably putting the brine down in anticipation of the ice we may be getting later tomorrow.

Ice stinks!!

[Nimbus]

Warm moist air overunning a cold high pressure dome is a recipe for freezing rain. Iced up tree branches and power lines combined with high winds are a bad mix. There will be a lot of power outages with this storm in areas that change over.

[angelwing]

I was just surprised it was so early, they usually wait until the storm starts. Also just took a break outside and the road here by the hospital is brined too.

[Category 5]

Philadelphia: 1”-3”

Can we put a "0" after the 1 and 3?

[ohiostorm]

What about Pittsburgh?

[JBG]

I wonder if the "split jet stream" scenarios almost always make a heavy I-95 storm unlikely. Are there any examples of Kocin-Uccinelli storms in a split jet envirnoment?

[Category 5]

I'm hearing about a possible few inches on the wrap around.

[Hurricaneman]

I think it will be all rain for me from here on out