Marine weather....here?!

[CelNav57]

We thought it might be interesting to add a portion of the forum to the discussion of marine weather.  It doesn't have much to do with celestial navigation but we do, hopefully, all utter the phrase, "clear skies".

How many of you like to predict the wx yourself using your own instruments?

Or, if you do use services or programs, which ones are you accustomed to?

Are you often correct in weather prediction?

[CarlosPindle]

Marine wx is probably a necessary hobby of us. Often the weather man is wrong. Most of them on TV look like they're dancing in front of a huge screen TV while flailing their arms about describing the cold front that's coming through and passing off the coast....tomorrow night.

I have a simple barometer, thermometer and windex/windvane (home made) that we use. It's very important to keep a watchful eye out to study the present conditions of the sky. To predict tomorrow's weather isn't that difficult. A week in advance is beyond my ability.

Weather is an interesting and fun even to study.

[Steeldreams]

It is a subject I am interested in and plan to take a course in it.

[craigsl]

Not being a great fan of electronics and knowing how they have let me down many times before I'll stick to simple instruments like Carlos mentioned- thermometer, barometer, wind vane.

But, I have enjoyed using Zygrib- the Beaufort arrows and barbs make it easy to understand, at least, wind direction and speed.

Do any of you guys know about cloud formation?  I don't know there names but know the huge clouds in the Summer often mean a storm will be coming sooner or later.

It would be nice to have a barograph just for fun.  $$$

Have you seen Windytv?  This is really neat-

Windytv


Craig

[pabrides]

As a pilot Ive been keen on weather phenomenon for many years, but I think there are probably many more terrestrial effects on weather than what the ocean provides.  Aside from occluded or fast moving fronts, hurricanes or typhoons (low pressure), near shore terrestrial influences, and large scale heating and cooling of the waters surface, what in the world causes instability over the oceans??? I would suggest ocean weather is more difficult to predict  without instruments.  Where did the old saying come from... "red sky at night sailors delight; red skies in the morning sailors take warning."  Thats a pretty broad weather pattern statement, but I assume it came from long experience. 

Wind shifts, rapid temperature changes, cloud formations, and general weather intensity do more to key in captains than anything else.  Regional weather anticipation helps a captain trim the ship for best sailing.  These days taking in the sheets is done in minutes, but in bygone sailing days it could take 30 minutes to an hour or more to bring a three or four masted ship to heavy weather readiness or heave to - a lot could happen in that time so perhaps captains were much more in tune with the weather than we are today.  As pilots we are taught to get ahead of the airplane; Im sure it was just as important for a ships captain to get well ahead of the ship. 

Off the East coast of Florida I saw seven huge water spouts lined up in a row sucking ocean into the air... they were about three miles away, but the weather over us was just fine.... Where did they come from?  I have no idea.

Thats about as far as my thinking takes me

joe

[CarlosPindle]

Joe, I suspect you could teach us a great deal about wx prediction or determination.

Call me stupid but I still have no idea how to understand Low or High pressure systems in the Northern hemisphere (or Southern Hemisphere either). Yes, in the Northern the High Pressure systems rotate clockwise and the Low Pressure systems counter-clockwise. But, in either is the air rising or falling? Bowditch Chapter 34 Weather Elements doesn't make it clear.

Oh well.

Carlos

[pabrides]

  in the Northern the High Pressure systems rotate clockwise and the Low Pressure systems counter-clockwise.  But, in either is the air rising or falling?  Bowditch Chapter 34 Weather Elements doesn't make it clear.  
Carlos

Hello Carlos,
No, Im not a weather guru, but i try to pay attention.  When you see a tornado or a hurricane you are watching an extreme example of a low pressure system.  Just watch what happens in and around a tornado and you get the general picture of weaker wide-spread lows. 

The reason you can see a tornado is because of all the crap it picks up.  We sense wide area lows with barometric pressure and wind direction/velocity. A High is never as intense (except perhaps micro-bursts) and behaves just the opposite of a low. 

The sail of a ship or the wing of an airplane creates on one side an area of low pressure which draws the wing or sail in that direction... The bottom of the wing or sail is an area of high pressure.  Low pressure means, I think?, low density air.  Put your hand in front of a fan and you feel a high... put your hand behind the fan and you feel a low. 

Cold air is dense; warm air is less dense. The fan itself, or the propeller of an airplane, is an engine that modifies air density - the engine that creates lows and highs in nature are the relative temperatures of air masses that cause them to rise or fall.  Coriolis effect modifies the direction of the wind (as I recall) into a circular pattern... otherwise the wind would rush directly into a low pressure area where it would then be drawn up into the sky..  When the heat engine (temperature differential) quits the tornado ends.... I think!

Moisture plays a big roll too.  When a cloud creates rain the act of condensation releases more heat which causes a storm to intensify.  Evaporation subtracts heat. 

Whether the lifting source is orographic or adiabatic the effect is the same - weather. Warm air rises; cold air sinks. Apply these principles to water and you understand why liquid boils as it does. Or ask yourself this... Why does a hydrogen or helium balloon rise?

I hope I remembered correctly.  
joe