Your barometer has dropped 3 mb per hour...what do you do?

[FantasyIsland]

Let's say you're cruising across the Atlantic, and you observe that the air pressure has dropped rapidly and you're expecting extremely high winds and rough seas.

What do you do to prepare?

[s/v Jedi]

Originally Posted by FantasyIsland

Let's say you're cruising across the Atlantic, and you observe that the air pressure has dropped rapidly and you're expecting extremely high winds and rough seas.

What do you do to prepare?

Determine location of storm center and attempt to get in the left front quadrant, then keep broad reaching south towards the equator.

[JohnT]

Which hemisphere are you sailing in?

[Paul L]

Download the latest GRIB file

[ChrisJHC]

Go outside and look around.
This will give you an idea of whether you’re going to be hit RIGHT NOW or you have some time to prepare.

Then get ready for heavy weather. The specific steps will vary depending on a whole range of factors.

[Rob_P]

Put that blasted barometer back on the shelf and use some duct tape on it to keep it there?

[belizesailor]

Originally Posted by Rob_P

Put that blasted barometer back on the shelf and use some duct tape on it to keep it there?

[emoji1787]

[JPA Cate]

I don't know about you, Fantasy Is., but normally on passages, the first thing Jim does is download the Grib files. This is because the day that the baro is already dropping has been presaged by pre-frontal clouds that will alert you roughly 3 days in advance to whatever's coming. Whichever hemisphere you're in, you should be aware from which directions come the strongest winds. What you're wanting to find or figure out is where whatever it is going to be by the time you get there, and you get to pick how you will avoid or prepare for it, by choosing the conditions under which your paths will coincide, or not. (It is feasible to heave to for a while to let something ahead of you blow through; other times whatever it is is going to nail you.) The models on the gribs can be split screen compared, so you can look at most models, sometimes 3 of 4 will agree, and the decision is easier.

Some people get weather VIA satphone. One time in Vanuatu, that one Oyster whose skipper had the satphone, provided cyclone warning about 12 hrs. in advance of the gribs, but eventually, it never went where it was predicted to go. You need to understand that the actual prediction is not going to be spot on, except in its generality, and in general, the ancient fishermen's ways of thinking about storm phenomena are the reflection of thousands of years of observation and some survival. You will know only approximately the wind strength and direction: gribs help with that but are still only guesses, no matter how pretty the charts are. However, accuracy is improving. The air around highs and lows still circulates the same ways, and weather systems travel time-displayed patterns.

Ann

[Breaking Waves]

Originally Posted by FantasyIsland

Let's say you're cruising across the Atlantic, and you observe that the air pressure has dropped rapidly and you're expecting extremely high winds and rough seas.

What do you do to prepare?

The barometer change is (generally) not predictive but rather is co-incidence with the wind - so if it has fallen rapidly it is most likely already blowing hard. You should already have prepared when you saw the clouds (2 days ago) and felt the air temp change (6 hours ago).

The barometer is better thought of like a depth sounder - if you have a grib (or other weather maps) it can help you more accurately place where you are in the systems. But by itself, with no other information, it does not help you predict all that much.

[Midnight Son]

Originally Posted by JPA Cate

I don't know about you, Fantasy Is., but normally on passages, the first thing Jim does is download the Grib files. This is because the day that the baro is already dropping has been presaged by pre-frontal clouds that will alert you roughly 3 days in advance to whatever's coming. Whichever hemisphere you're in, you should be aware from which directions come the strongest winds. What you're wanting to find or figure out is where whatever it is going to be by the time you get there, and you get to pick how you will avoid or prepare for it, by choosing the conditions under which your paths will coincide, or not. (It is feasible to heave to for a while to let something ahead of you blow through; other times whatever it is is going to nail you.) The models on the gribs can be split screen compared, so you can look at most models, sometimes 3 of 4 will agree, and the decision is easier.

Some people get weather VIA satphone. One time in Vanuatu, that one Oyster whose skipper had the satphone, provided cyclone warning about 12 hrs. in advance of the gribs, but eventually, it never went where it was predicted to go. You need to understand that the actual prediction is not going to be spot on, except in its generality, and in general, the ancient fishermen's ways of thinking about storm phenomena are the reflection of thousands of years of observation and some survival. You will know only approximately the wind strength and direction: gribs help with that but are still only guesses, no matter how pretty the charts are. However, accuracy is improving. The air around highs and lows still circulates the same ways, and weather systems travel time-displayed patterns.

Ann

I know, in the Northern latitudes, you see sun dogs, 48 hours before you get your butt handed to you.

[Windswept-windy]

Originally Posted by s/v Jedi

Determine location of storm center and attempt to get in the left front quadrant, then keep broad reaching south towards the equator.

Agreed ^^Barometers are a powerfull tool, depending on what hemisphere/direction to run!!

[Breaking Waves]

an article we wrote some years ago related to barometer interpretation/use:

Weatherrevis.pdf