Gulf Stream Crossing: Weather Window

[b-rad]

Im looking to make the crossing from miami to the banks with a destination of great harbor cay in the berry islands. Im watching the weather for friday night.
FRIDAY...SOUTH SOUTHEAST WINDS 6 TO 9 KNOTS. SEAS 2 FEET. DOMINANT PERIOD
5 SECONDS. INTRACOASTAL WATERS A LIGHT CHOP. CHANCE OF SHOWERS AND
THUNDERSTORMS.
.FRIDAY NIGHT...NORTHEAST WINDS 14 TO 17 KNOTS. SEAS 2 FEET BUILDING
TO 2 TO 4 FEET. INTRACOASTAL WATERS A MODERATE CHOP. SLIGHT CHANCE
OF SHOWERS.
.SATURDAY THROUGH SUNDAY NIGHT...EAST WINDS 15 TO 20 KNOTS WITH
GUSTS TO AROUND 30 KNOTS. SEAS 3 TO 5 FEET. INTRACOASTAL WATERS
CHOPPY IN EXPOSED AREAS.
.MONDAY...EAST WINDS 13 TO 16 KNOTS. SEAS 2 TO 4 FEET. INTRACOASTAL
WATERS A MODERATE CHOP

So would you go, wind isnt going to go north untill Im half way across. I figiure I should be well across before anything get dicey. Any one crossed the bank with a strong east wind, Besides a long motor hows the water condtions. Thanks

Brad

[w32honu]

Early Friday sounds ideal............

But I would not want to be in the middle of the stream with a strong northerly wind (and building). (Later forecast)

Also you have to cross the bank to the Berries............ Be wary of the forecast for strong easterlies at 30 kts. Especially in the vicinity of NW Channel Light on the east end of the Bank. Deep water (The Tongue) meets the Bank here and it could be dicey in a strong easterly flow.

Perhaps go early and whole up in Bimini or Cat Cay. If it is a front moving thru, you can then ease on down to the Berries on a westerly breeze (after frontal passage).

Have fun.............

[Tingum]

30' boat- NO GO!

[capngeo]

I wouldn't do it for fun.... If I were delivering, maybe, but a pleasure cruise it ain't gonna be!

[Captain Bill]

Why are you still here? I looked at the forecast for today and and tomorrow. The wind does not get significant until very early Saturday morning. It doesn't get any better than the forecast you have for the next 40 hours. Even at 5 knots the stream crossing is only 10 hours. I would leave today if I could, if not during the day I would leave tonight and arrive in daylight tomorrow. I don't know what your planning speed is but you should be do it in less than 30 hours at 5 knots.

[Tingum]

Guess I am not as brave as you all. I have only been a Merchant Marine Master since 1978. 17 knots from the NE on the nose in the Gulf Stream, in a 30' boat, no thank you!

[doug86]

hope and wishful thinking will not change the forecast. A good weather window for the GS looks like a pair of French Doors, not a port hole...

The Banks will really suck in NE or E, and if you get to the NW Light at the ebb...

I'm with Bill, I would be thinking about leaving tonight or before dawn tomorrow:

AMZ651-671-282115- COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM- WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-
427 AM EDT THU APR 28 2011
TODAY SOUTH SOUTHEAST WINDS 10 TO 13 KNOTS. SEAS 2 FEET. DOMINANT PERIOD 4 SECONDS. INTRACOASTAL WATERS A MODERATE CHOP. SLIGHT CHANCE OF SHOWERS THROUGH THE DAY. SLIGHT CHANCE OF THUNDERSTORMS IN THE LATE MORNING AND AFTERNOON.

TONIGHT SOUTH WINDS 6 TO 9 KNOTS NEAR SHORE TO SOUTH SOUTHEAST 9 TO 12 KNOTS WELL OFFSHORE. SEAS 2 FEET. DOMINANT PERIOD 5 SECONDS. INTRACOASTAL WATERS A LIGHT CHOP. SLIGHT CHANCE OF SHOWERS.

FRIDAY SOUTH SOUTHEAST WINDS 6 TO 9 KNOTS. SEAS 2 FEET. DOMINANT PERIOD 5 SECONDS. INTRACOASTAL WATERS A LIGHT CHOP. CHANCE OF SHOWERS AND THUNDERSTORMS.

FRIDAY NIGHT NORTHEAST WINDS 14 TO 17 KNOTS. SEAS 2 FEET BUILDING TO 2 TO 4 FEET. INTRACOASTAL WATERS A MODERATE CHOP. SLIGHT CHANCE OF SHOWERS.
National Weather Service Marine Forecast

[Captain Bill]

Originally Posted by Tingum

Guess I am not as brave as you all. I have only been a Merchant Marine Master since 1978. 17 knots from the NE on the nose in the Gulf Stream, in a 30' boat, no thank you!

The forecast is for the wind to go NE at 10 knots between 11 PM friday night and 2 am Saturday morning. Only getting to 14-17 by 5 am. If he leaves even as late as 10 am Friday morning if he isn't across the gulf stream from Miami 13 hours later he's probably going the wrong direction. Wave heights are forcast to reach 4-5 feet in the middle of the stream at 5 am Saturday morning. On the east side their still forcast to be 1-2 feet at that time. After he gets into NW providence channel his course will be ESE. Depending on his boat he might even be able to sail it with a NE wind. If he leaves tonight he'll probably have to motor or motorsail the winds will be so light. I certainly would not wait until Friday night or Saturday to go. That's the thing with weather windows, they open and close, right now it's open, but it won't stay that way.

[w32honu]

Advice is one thing......

Pressuring someone into a decision because we think we are right is another.

His boat. His decision.............

Besides, if this window does'nt do it. Maybe the next one will.

[doug86]

What pressure? Who has put pressure on the OP? We are providing him with our experience and relevant data.

[Captain Bill]

Originally Posted by doug86

What pressure? Who has put pressure on the OP? We are providing him with our experience and relevant data.

No kidding, simply pointing out that the Window is open and will close tomorrow is not pressure, it's pointing out an opportunity. If his boat won't be ready in time then he'll have to wait for the next one.

The OP asked about crossing the banks in a strong NE or east Wind which has not been well addressed. From an advice point of view I would aim for the south edge of NW Providence channel (NWPC) instead of crossing the banks. First of all heading for NWPC allows you to cross the stream on a easterly heading with little or no southing against the stream required. This actually boosts your speed by a couple of knots as all of your boat speed is spent going east and you let the stream take care of the northerly component. The second is that the banks are shallow which means that the waves tend to steep and choppy whereas the deep water of NWPC will tend to longer period and more comfortable. Heading for Bimini or Cat Cay from Miami means a lot of southing and a slow crossing taking a couple of knots off of the VMG instead of adding to it. Also once in NWPC the course to Great Harbor is better if the NE winds arrive earlier than forecast.

Maybe we could get more details from the OP on his planned course and boat speed.

[b-rad]

I would love to leave today/ tonight unfortanatly having a job (and keeping it) requires me to work tomorrow (friday) , I have 10 days off for my trip. I have been thinking about going the nwc route and letting the gs push me north to it. The last time I did this trip on a friends boat we had 15-20 from the N and the stream was ok the NWC was miserable. I estimate boat speed to be 5.5 on average but with 10 +kn wind the boat generaly will do 6-6.5. Ill motor or motor sail to get me there . Im more worried about not making great harbor and being stuck out in the east winds.

[Captain Bill]

It looks to me like you will need between 23 and 30 hours depending on wind and tidal currents. If you can't leave until tomorrow evening I doubt you'll reach Great Harbor before the wind goes easterly and picks up. It looks like the wind will still be east on Tuesday but be so low as to not be a problem and by Wednesday it will be repeating the pattern we're seeing today.

[hogfighter]

May I ask why you feel the need to stay in deep water? Wind is not going to be blowing for long in the GS, hence the reason the NWS is only showing seas of 3-5 feet. IMHO, the crossing won't be too bad (not pleasant, but not scary) if you leave early enough, but maybe think about heading to Great Harbor Cay just north of Bimini in shallow water. Are you comfortable with night passages?

[Hud3]

The front that will be moving through your area on Friday night/Saturday morning is the same one that spawned dozens of tornadoes, killing at least 250 people at last count. It's got a heck of a lot of energy, but it looks like the tail end, the part that you'll experience, isn't nearly as powerful as the parts north of JAX. Still, if I were you, I'd give this one a bit more study before assuming the NWS forecasts will be spot on accurate.

NWS Radar Mosaic 1858 UTC, 28APR11.