As usual, Hud3 provided brilliant and thorough response.
I'd like to add a factor to the discussion: The 500mb line.
Several years ago, hurricane
NOEL held up the departure of the Caribbean 1500
which leaves from Hampton, Virginia. NOEL didn't make landfall there and headed up the east coast
just off shore of Virginia and Maryland
We were leaving Annapolis
when the 1500 left the southern Chesapeake Bay
so we were 2 days behind in leaving the Bay headed for the Gulf Stream
We sailed in some really, really rough weather
and ended up with a broken boat in Bermuda. Upon arrival, and within a few days, many well founded, larger yachts showed up with a lot of damage due to the sailing in the same rough seas. I think several people died in an attempt to abandon ship, sailing from Newport
I could go on about, back to the 500 mb line.
I had never heard of it until that trip. Later, I mentioned to Steve Black how bad the weather
was and he told me that the Caribbean 1500
fleet intentionally sailed south of the 500mb line, knowing how rough the weather can be north of it when lows are passing through.
Apparently, the low pressure storms that spun off of the back of NOEL were trapped north of the 500mb line (which was just south of the mouth of the Chesapeake) and caused all sorts of havoc. That's how I remember it.
The lesson was: Sail south of the 500mb line when leaving the Chesapeake, heading for the BVI's, in the fall. That's what I was told and it makes sense, as explained to me.
Can anyone add to this or explain it in a better way?