Our Weather Window - Hampton Roads, VA to Boston Harbor, MA

My friend Cliff on Oasis, a 70 foot Delta ocean going trawler, currently heading north called it three days ago (Monday) when he said that Friday will be the start of a weather window.  Cliff has 20 plus years of cruising experience.

That said, when he made that prediction the weather was, in a word, "horrible."  The deep low Monday over the western plains with a trailing cold front down through Texas kicked up massive thunderstorms and a Category 5 tornado that wiped out an Oklahoma town and took 16 lives.  That weather system is still dominating our weather as I write this article.  There is rain along the entire east coast.  A warm front is approaching Norfolk and the temperature outside is already 70 degrees.

Current conditions as of Wednesday, April 30

My friend and soon to be crew member for the trip north, Phil, turned me on to a thread pertaining specifically to our trip north.  The person initiating the thread was a sailor, and his concerns pertained to a sailboat transiting at 5 to 6 knots.  The respondents, who also appeared to be sailors, commented on four key issues that I must also take into consideration; weather windows, favorable winds, temperature and the Cape Cod Canal (CCC).

Temperature: You definitely need warm clothes on a sailboat at this time of the year.  We on the other hand will be warmly ensconced in the cabin.  It is highly unlikely that we will go on deck except for a constitutional if we are on calm seas or if for some reason we need to make port.

The Cape Cod Canal: The CCC is definitely an obstacle for a sailboat as the current reaches as high as 4 knots each day.  Great if it's going with you.  Not so good if it's against you.  The CCC is 7 statute miles long.  The 63 can maintain 8 knots by hitting the power (30 gallons an hour at 12 knots).  So the cost of powering through the canal is 23 additional gallons.  Fortunately for us, slack tide is at 7:43 AM on Sunday morning.  The canal is at our 394 NM mark or 46 hours from departure.  Assuming an 8 am departure we arrive at the canal at slack tide.  Further, we can adjust our speed while underway to hit our mark on time.

Finally, we get to the most important part.  The weather window.  We appear to have ours.

OVERVIEW:

The forecast for Friday, May 2, the day of our departure, shows the low pressure that has been wreaking havoc for the past four day moving off to the northeast as high pressure builds in from the southwest.

NOAA forecast for Friday, May 2

Saturday's forecast shows the isobars (pressure gradients) moving even further apart indicating lower wind speeds.  The low moves even further north over Canada.

NOAA forecast for Saturday, May 3

Sunday shows a low forming over northern NY with a trailing cold front along the coast.  Possibility of showers and increasing winds.  Possibly a problem but not when viewed in relation to our route as  explained below.

NOAA forecast for Sunday, May 4

MARINE FORECASTS: Now we look at specifics.

Note: In the following paragraphs I show a relevant range of forecasted conditions pertaining to our location on each day of our cruise.  The symbol *** shows the specific forecast(s) that pertains to our transit of that section of the coast.

FRIDAY: Starting at our point of departure from Hampton Roads, the marine forecast is very favorable with an improving trend (lower winds) as the day progresses..

THU NIGHT:  SW WINDS 10 TO 15 KT...BECOMING W AFTER MIDNIGHT. WAVES  2 FT.

***FRI: NW WINDS 10 KT...BECOMING SW IN THE AFTERNOON. WAVES 2 FT.

***FRI NIGHT: SW WINDS 5 TO 10 KT. WAVES 2 FT.

SATURDAY: North of Cape May, where we will be on Saturday morning, the winds and seas are favorable with west winds between 5 and 10 knots and seas 2 to 4 feet.

FRI: W WINDS 10 TO 15 KT. SEAS 3 TO 5 FT.
FRI NIGHT  SW WINDS 10 TO 15 KT. SEAS 2 TO 4 FT.  

***SAT: W WINDS 5 TO 10 KT...BECOMING SW. SEAS 2 TO 4 FT.

***SUN: W WINDS 10 TO 15 KT...BECOMING NW AFTER MIDNIGHT. SEAS 2 TO 4 FT.

SUNDAY MORNING EARLY:  As we arrive at the Cape Cod Canal the weather gets a bit more complicated but we find ourselves in protected waters.  We could see seas building on Saturday night to 5 feet as we approach Block Island.  The forecast for Sunday night does not effect us as we are will past the CCC and into Cape Cod Bay.  That said you can see that the winds and seas kick up as they day progresses.

SAT:  SW WINDS 5 TO 10 KT. SEAS 3 TO 5 FT.

*** SAT NIGHT: SW WINDS AROUND 10 KT. SEAS 3 TO 5 FT.

SUN: SW WINDS 15 TO 20 KT. SEAS 3 TO 5 FT.
SUN NIGHT: W WINDS 15 TO 20 KT WITH GUSTS UP TO 25 KT. SEAS
 4 TO 6 FT.

SUNDAY MORNING THROUGH NOON: The Sunday forecast that pertains to our transit of Cape Cod Bay shows winds picking up (10 to 15 knots).  However, having transited the CCC we are now running within 5 miles of shore and we should be in calm waters with a southwest wind.

SAT NIGHT: SW WINDS AROUND 10 KT. SEAS AROUND 2 FT.
*** SUN: SW WINDS 10 TO 15 KT WITH GUSTS UP TO 20 KT. SEAS AROUND 2 FT. A CHANCE OF SHOWERS.
SUN NIGHT: W WINDS 10 TO 15 KT WITH GUSTS UP TO 20 KT. SEAS AROUND 2 FT.

SUNDAY AFTERNOON: Finally, we arrive in the Boston Harbor area where we transit President Roads, the Hull Gut and Hingham Bay on our way to our destination.  We just may need to don our rain gear as we pull in to our slip at Hingham Ship Yard Marina.  Even the gusty winds will be mitigated as we dock by the marina's location, which is considered a hurricane hole.

SAT NIGHT: SW WINDS 5 TO 10 KT. WAVES 1 FOOT OR LESS.

*** SUN: SW WINDS 5 TO 10 KT WITH GUSTS UP TO 20 KT. WAVES 1 FOOT
 OR LESS. A CHANCE OF SHOWERS.
SUN NIGHT: W WINDS AROUND 10 KT. WAVES AROUND 2 FT

Written by Les