Wednesday, October 24, 2012

When the statistically best model hasn't wavered..

It may be time to update my blog..

The ECMWF is the best model-- hands down. All models have shortcomings, but when you crunch the numbers it sits on top. It's been fairly consistent with the overall track of Sandy.

It has been consistent with bringing the storm ashore far enough south that:

1. Most of our area gets a decent rain ( half inch far SW to 2-3 inches N and E of LYH)

2. As the storm wraps around, we sit on the SW side of the low in cold air and HEAVY snows fall in the Mountains. Some flurries and snow showers make it east of the Mts.


Here is the snow map- Looking at the model data, this would be HEAVY wet snow. Some of these locations could see HUGE amounts but between the wet nature of the snow and warmer ground I don't think anyone sees 20 inches.

Couple points--

1. The storm is forced NW by blocking to the east and a short wave diving in from the west. Sometimes blocking is under done and as a result, a more southwest landfall is possible. Conversely, sometimes blocking is OVERDONE and a more north landfall is very much on the table.

2. VERY often cold is overdone. It's common in the winter to see a cold snap 5 days out and you think low teens is possible over night and then it's not as strong and it's nowhere near that. So, with that-- even the perfect track that COULD bring a little snow as modeled COULD end up being to warm. Further, models struggle with very moist large systems with latent heat release-- I'm not sure how to quantify this impact just saying that it will have an impact.

3. Rain could have a sharp cut off-- Could see places east of LYH get close to 4 inches and places SW of SML get a quarter inch.

4. We are still 5 days out. With the tropical nature and the more difficult nature of those tracks combined with an extreme block, we may not have something nailed until we see the white of it's eyes.

5. What can you promise me, Keith?

This will be a huge event. I just read a report of 2 dead already from the impact in Jamaica. Further, it may not make landfall to near Boston, but it will be huge for someone. And, some snow will fall on the backside-- I'm about certain Snowshoe, Garrett county and Somerset PA will have accumulating snow.

Sandy is impressive!

The media will be all over this and it will be a fascinating storm to watch-- regardless of it's impact here locally.

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