Saturday, October 29, 2011

Winds Building Offshore To Make A Move Inland; Gusts over 60 mph Possible Later...

Media reports indicate over 1,000,000 are now without power in the Northeast - and I hate to tell you, we're just getting started with this, as the winds have yet to come - and the snow will continue to fall in many areas into tonight.

Below is the latest visible satellite image and surface weather observations.  The thin green lines are isobars, or lines of equal pressure.  The closer the isobars are to one another, the stronger the wind is blowing in those areas:

You can see the low pressure center offshore (the closed - though partly off screen - green circle about 200 miles South/Southeast of New York City).  It will continue to grow stronger into the evening and overnight hours, which will result in those isobars getting even more tightly packed, signaling an increase in the winds at the surface level.

The winds at a data buoy located at the entrance to New York harbor (which is about 25 miles off of Long Island and about 40 miles Southeast of Manhattan) are steadily increasing, with the most recent observation (see graphic below) showing steady winds of 40 mph with gusts up to 48 mph.

This trend will continue into the evening hours as the low pressure deepens, with strong and gusty winds spreading inland from North Jersey and NYC up through New England.  

This process is what we call a "bomb", where the surface low deepens very rapidly and over a relatively short period of time.  This is a classic pattern that we'd expect to see with a "Nor'easter" type storm - but certainly not at the end of October!

I would not be surprised to see wind gusts in excess of 60 mph later this evening or tonight across much of this region, particularly along the coastline where there are less trees and buildings to break-up the momentum of the winds coming in off of the ocean.

GFS model forecast valid 11pm EDT this evening.
55-65 mph wind gusts indicated at orange shaded areas.

Even inland, I would expect sustained winds of 30-40 mph with gusts to 50 mph in many areas.  This will bring down trees and power lines that are already under pressure from the weight of the heavy wet snow that has fallen and will continue to fall...

In the precipitation department, things are still pretty much on track from my update at midday.  The image below is the snowfall forecast from that post, please refer to that post for additional details.

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Anonymous said...

Rob, you were one of the few calling for this earlier in the week. Have to admit I thought you were crazy at first, but you were spot on like usual. Thanks for the heads up! Frank in NYC.

Rob In Texas said...

Anonymous, thanks for your kind words. Glad we were able to give you some advanced notice...