Hermine From A Southern New England View

Early this morning Hermine became the first Hurricane to strike Florida since Hurricane Wilma in October of 2005.  Hermine is now moving across the SE US with damaging wind and extreme rainfall.  The storm will emerge into the Atlantic off the North Carolina coast tomorrow afternoon.  It will begin to regain strength as it turns into a hybrid type storm with both tropical and extratropical characteristics.  The storm will sit for several days and will probably become a hurricane again while sending heavy surf and storm surge onto the Northeast and Mid Atlantic beaches.  Heavy rain and damaging wind will accompany the water rises in the Mid Atlantic.  Will we see any of that in Southern New England?

General Overview
Here is the latest position and forecast track from the National Hurricane Center as of 5 PM.  Tropical Storm Watches include the Connecticut shoreline.
NHC 5 PM Hermine headlines, track, warnings
On satellite she is starting to take the look of Nor'easter which is expected.  That is why Hermine is forecast to transition to a non tropical storm over the weekend.  A tropical cyclone derives its energy from the warm moist ocean waters.  A non tropical low derives its energy from temperature differences (baroclinicity).  
NOAA GOES EAST Rainbow IR satellite
The storm should creep northeast until later Sunday afternoon.  At that point the low will be captured underneath a developing ridge in SE Canada.  A trough will build in the west US and the storm will literally have no where to go.
18z NAM 500 mb vort Monday 2 AM (image NCEP)
24 hours later Tuesday 2 AM
18z NAM 500 mb vort Tuesday 2 AM (image NCEP)
So that means the Mid Atlantic and Southern New England get rocked right?  Well no not necessarily.  High pressure to the north on Sunday should suppress the moisture south of our region.  This doesn't include coastal Southern New England.  Wind and rain will begin to impact the south coast on Sunday.  This is a very unique situation.  Look at this map of potential tracks
18z forecast model tracks Hermine (image Spaghetti Models)
   Any of the northern tracks bring wind and rain more quickly.  So here is what to expect.

Saturday
Enjoy the day.  Mostly sunny with light winds and temps in the 70's.

Sunday
Away from the coastline this is a nice day.  Increasing clouds and rain chances increase in the evening south of Providence/Hartford/Plymouth.  High temps in the low 70's with increasing winds.

Monday
Off and on rain showers.  Heavy rain bands will have the potential for tropical storm force wind gusts especially near the coast.  Moderate power outage potential south of the Hart-Prov-Ply line and low threat north of there to a Springfield-Worcester-Boston axis.  Temps in the upper 60's thanks to the rain but muggy due to the tropical nature of the storm.  I am not expecting flooding rains north of the H-P-P line but some flash flooding is possible south of it.  Coastal areas will see water rises and heavy surf leading to some coastal flooding.

Monday Night into Tuesday
The low will linger offshore.  It has nowhere to go.  The water is warm south of New England.  The storm will restrengthen and any bobbles north will bring strong wind/rain to the region.  However if you let a car idle in the same spot without driving to a gas station eventually you will run out of fuel.  In this case Hermine will exhaust the warm tropical water beneath it due to a process called upwelling.  The pounding surf she generates will draw cooler waters beneath the ocean surface to the top and thus Hermine loses her heat source.  She will steadily weaken.  This won't occur until Wednesday so Tropical Storm conditions will be possible throughout the day Tuesday.  The closer to the coast the higher the threat.
WSI Hermine overview
This graphic shows the strongest winds will be in South Coastal New England.  Winds can gust over 60 mph in these regions.  In yellow we can expect wind gusts 40-50 mph at times.  In reality this is no worse than any of our Nor'easters but given all the leaves are still on the trees there is a higher likelihood of a tree being blown over.  It should be a bad storm in coastal New Jersey/Delaware.Maryland but we should do okay in Southern New England.  Nantucket, MV, Long Island etc. will take a good blow from the storm but as long as it doesn't jog to the north I think the impact will be moderate.

The biggest thing is stay the hell out of the water this weekend.  Be careful at cliffs for rogue waves.  If you want a picture of the surf make sure you have a path to escape in case of rapid water rises.  Beach erosion will be a major problem due to days and days of pounding surf.

I will update tomorrow have a good night/weekend everyone

-Zack Green

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