What's in a New England Hurricane- Part 2

(This will take the place of the weekly weather take)

For part one see here.

The calendar reads August 22 and right on time the Atlantic Hurricane season has sprung to life.  Tropical Storm Fiona has weakened to a tropical depression but a new tropical depression has formed near the Cabo Verde Islands in the Eastern Atlantic.

5 PM EST Atlantic Basin Overview (National Hurricane Center-NHC)

 Tropical Depression Seven will become Tropical Storm Gaston and then become a Hurricane (and probably a major hurricane) but it should steer clear of land for a long time.  Way down the road, say 10-12 days it may make a turn east of Bermuda before approaching Newfoundland but this is a long way off.  We will have to watch the surf for Labor Day weekend at any rate.  This happens most years because August 20- October 20 is the peak of every season with September 10 as the peak of the peak.

NOAA Hurricane Season Peak

Storms literally form anywhere in late August.  Here is a scatter plot of where storms in the North Atlantic and East Pacific have formed between August 21 and August 31

Storm formation August 21-21 1851-2009 (Image NHC)

Now historically speaking here are the tracks storms typically take in August and September.

August Prevailing Tropical Cyclone Tracks (NOAA/NHC)

September Prevailing Tropical Cyclone Tracks (NOAA/NHC)

I post all of this because the other X in the active tropical cyclone image at the top of the page is forecast to move towards the Bahama's by Saturday.  Any time a tropical cyclone gets near the Bahama's it has a chance to impact the United States, including New England.  Here is the forecast.

NHC 120 Hour Tropical Cyclone formation chances Monday 2 PM 

Will the storm definitely develop?   No it might not.  The American GFS model doesn't really develop the wave.  The EURO model does and it drive a powerful storm into the Gulf of Mexico.  Both solutions are on the table.  I personally believe the lead wave will form and it will get the name Hermine (they should just change that name to Hermoine and get it over with).  Atlantic sea surface temperatures are very warm in the Southwest part of the basin and into the Gulf of Mexico.

2 day average sea surface temperature (image Weatherbell)

Any time a tropical cyclone gets into the Bahama's people in New England have to pay attention.  Its where our last hurricane was born.

Hurricane Bob August 15-19, 1991
Bob first formed on August 15, 1991 near the Bahama's from the remnants of a cold front that pushed off the east coast.  Here are the four panel reanalysis charts at various levels of the atmosphere.  Please look at the top right image.  It shows an upper level high pressure system (ridge) in the NW Atlantic and a upper level low (trough) diving east in the Upper Midwest.

NCEP/NWS/NOAA reanalysis August 16, 1991 8 PM 

Those factors led Bob to move north instead of west or east.  By Monday August 19 Bob was a strong Category 2 Hurricane with winds of 105 MPH racing towards Block Island and Buzzards Bay.  The reanalysis shows why the storm continued north instead of missing out to sea.  It was blocked by that upper ridge.

NCEP/NOAA/NWS reanalysis August 19, 1991

That afternoon Bob made landfall in Block Island and then in Newport.  He drove a 10-15 foot storm surge up into Buzzard's Bay and winds reached 130 MPH in Truro, MA.  Over 2 millions people lost power and 17 people lost their lives.  Over $1 Billion in damage was recorded.  If you remember my post about Connie and Diane the damage was caused by river flooding.  In Bob the damage was from wind and water, but not rainfall.

Hurricane Bob track/rainfall (NWS Boston)

The rain was heavy in Central and Western MA, Eastern CT and SE NH and S ME.  But it wasn't the 15-20 inches in 5 days like the 1955 twins.  Instead the counter clockwise flow around the Hurricane funneled storm surge into Buzzards Bay.  Here is a picture of the Menaahant Yacht Club in East Falmouth, MA courtesy of Doc Taylor before and during Bob

Before Bob

During Bob

Via the NWS Boston 25 year anniversary post
Coastal communities bore the brunt of the storm, with sustained winds between 75 to 100 mph. Peak wind gusts to 125 mph were recorded on Cape Cod in the towns of Brewster and North Truro, as well as in Wethersfield, Connecticut. The highest sustained wind of 100 mph, was recorded in North Truro. Block Island reported sustained winds of 90 mph, with gusts in excess of 105 mph (maximum speed of equipment). Wind gusts to near 100 mph were recorded in Newport and by the Navy Ship Samuel B. Roberts, which was riding out the storm on the east passage between Newport and Jamestown, Rhode Island. Additionally, there were four reports of tornadoes as Bob came ashore. The lowest barometric pressure was recorded by the USS Valdez while in the east passage of Narragansett Bay, with a reading of 28.47 inches. 

Hurricane Bob caused a storm surge of 5 to 8 feet along the Rhode Island shore, but drove a surge of 10 to 15 feet into Buzzards Bay. The Buzzards Bay shore east to Cape Cod was hardest hit. The highest surges, of 12 to 15 feet, were observed in Onset, Bourne, Mashpee and Wareham, at the head of Buzzard's Bay. Cove Road, in Mattapoisett, Massachusetts had 29 of 37 homes destroyed, while Angelica Point, Massachusetts lost 32 of 35 homes along the shore. Boat damage was significant, as many boats were torn from their moorings. Extensive beach erosion occurred along the shore from Westerly, Rhode Island eastward. Some south facing beach locations on Martha's Vineyard and Nantucket islands lost up to 50 feet of beach to erosion.

The storm was really bad in SE coastal New England.  So now we have recapped 2 different years both with devastating effects in Southern New England for different reasons.  Hurricanes have a variety of hazards from coastal flooding to inland flooding to wind damage and tornadoes.  The next post will look at some of the stronger Hurricanes in the Southern New England record.

-Zack Green