Posted by: coastlinesproject | September 4, 2016

Hermine, Bill Ryan report:

At 0800 on Sunday, Hermine was located at 37 N, 70 W or 300 miles SSE of Montauk.
Winds are at 65 mph with movement still to the ENE (65 degrees) at 12 mph.

Track: Hermine is expected to stall later this afternoon and then drift slowly to the NNW until early on Tuesday. At that point it will move off to the NE crossing south of Cape Cod on Wednesday.

Intensity: The intensity forecast has Hermine at its strongest on Monday night, perhaps returning to hurricane status. This strengthening is a result of Hermine’s interaction with a closed (“cutoff”) low moving in from the west after a trip across the US. This interaction is why the NHC refers to Hermine as an “extra-tropical” storm. The cutoff low will bring a deep layer of very cool air above Hermine. When matched with the still warm ocean, this will cause upward motion and a re-invigoration of Hermine. This strengthening will be short-lived and Hermine is expected to begin weakening on Tuesday morning as it drifts north of the Gulf Stream into cooler water.

For Cape Cod, winds will dance up and down over the next few days. The NHC forecast has Hermine remaining south of the so-called “benchmark” of 40 N, 70 W. Given Hermine size, this puts the Cape on the edge of the tropical storm force wind band (TS winds extend ~ 200 miles from the center). There will be several pulses in the winds over the next 48 hours. Although Hermine will move closer to Cape Cod Wed and Thurs, it will be weakening at that point.

Questions:
1. Hermine is still moving ENE. This eastward movement is already longer than yesterday’s forecasts expected. Although stalling is still expected, every hour of eastward movement will reduce threat to the mid-Atlantic ocean beaches and to Cape Cod and southern New England.
2. The interaction of a tropical storm with an upper level low is not a common one and the hurricane forecast models often have difficulties with them. The uncertainty level is still pretty high as a result.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: