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juro 07-23-2001 01:13 PM

Wind Expertise -or- knowledge anyone?
Wind plays such a big factor in casting, sightfishing, forage behavior, temperature, float-tubing, kayaking, the list goes on...

Does anyone have any knowledge of wind they could share?

It seems to increase through the day in coastal areas. Is there a peak time / lull and what affects it?

It seems to be calm in morning and in evening in general. If it's not calm in morning, can one expect a windy day throughout?

What resources exist to learn more about it? What are the best prediction sites on the web?

thanks in advance

Nick 07-23-2001 02:34 PM

From what I understand, a great deal of coastal wind has to do with the temperature changes (and heat coeffecients) of different bodies. Land areas have a high gain and loss of heat rate. They cool rapidly in the evening, and warm rapidly during the day. The water on the other hand, is relatively consistent. What happens is throughout the day, the land heats up, causing the air to rise, and the cooler air over the water replaces it. (at least during an onshore breeze) From here on is a hypothesis, so I'm not sure if its correct. I suppose that this time of year, the land cools to about the same temp as the water during the evening, thus not too much wind. As the land heats up during the day, the wind picks up. As it cools again in the evening, it dies down again. This has been my experience for the most part, at least on the days when you wake up and its calm. This does not take into effect different pressures from weather systems, as well as the different effects of fronts and what not. So thats my theory, any others?

October Caddis 07-23-2001 02:42 PM

Not an expert but do know that in summer as air heats up over land it rises and the cooler heavier air over the ocean will take up the void left by the rising warmer air and creating on shore afternoon winds.
I know out here in the NW that during a high pressure system we can get off shore winds early in the morning as the warmer air over the low lands rises and the cooler mountain air sinks down to replace it. By late morning though the wind has changed to onshore. Also at sunrise above Goldbar on the sky I've seen strong winds coming down the river from the near by mountains for 15 or 20 minutes then seem to quit as temps equalize. Of course then you have highs and lows in the area with highs going clockwise and winds starting from the north and lows counter clockwise and begining from the south as both types of systems aproach from the west.

Another interesting question has anyone out there learned to read their local tides by the moon phases only. I know that it can be done and it is different on both coasts. When I lived in Hawaii a lot of the Hawaians were just increadable at doing so.

Ishmeal 07-23-2001 03:03 PM

Welcome to Weather101...
I like to compare the information on and military aviation carreer has given me a fairly good weather background but it's a "probability" game with "educated" guesses mixed in with a basic weather foundation...
Intellicast has very good "radar loops" that show weather movement over a six hour period and has good visuals on fronts and areas of concern...the "surface maps" show a graphic representation of "High" pressure and "Low" pressure areas and the white "isobar" gradient lines tell alot about wind speed and direction ande the overall strength of the pressure system. Check out hurricane isobars and you get the picture.
I'll start off with the "radar loop" to get the big picture, trend and frontal information...then I will go to the surface maps to locate "low" pressure areas (counter clockwise flow) and "high" pressure areas (clockwise flow)...(south of the equator "lows" are clockwise and "highs" are counter clockwise...I shall only consider the northern hemisphere for this discussion)...There WILL be a test soonerorlater!

If the isobar lines (the white lines that circle the high/low pressure areas) are widely spaced the pressure gradient is weak and the winds will be light...tightly spaced isobar lines would indicate a stronger pressure gradient and will produce stronger winds.
As far as the beach weather is concerned...weak pressure gradient lines will produce little or no the cool morning passes and the sun heats up the land mass, air over the land mass heats and, since warm air rises, the "void" created by this rising warm air must be filled/replaced with more air and what you have is a "shore breeze" that starts when the land mass heats up and deminishes as the sun heads low in the west which cools the land mass and the shore breeze dies off...
If the isobars are tightly spaced the resulting winds will "overpower" the shore breeze and there will be a prevailing breeze/wind driven by the location of the center of the "high" or "low" pressure areas...these winds will parallel the isobar lines seen on the surface maps.
Closely spaced isobar lines=very windy
Widely spaced isobar lines=slightly windy
Very weak pressure areas with widely spaced isobar lines will inspire the mid-morning shore breeze (caused by land mass warming and hot air rising being replaced by the cooler air from off shore) that dies off as the sun goes down.
If it's windy in the morning the wind will be "driven" by the pressure gradient isobars which will overpower the land mass warming mechanics...and the wind will continue until the pressure system moves on and pressure eases thus spreading out the isobar lines on the surface map...wind calm!
Weather reports play the odds with educated guesses and tend to be "conservative"...S_ _ T happens!?

BLAH BLAH BLAH...I'm getting carried away and will quietly sit back down and field any question (remember, I'm a pilot, not a weather person...)
Thank you for your time and can take back the soap box!

SOLO 07-23-2001 04:54 PM

Another good WX infornation source is the national weather service.

juro 07-23-2001 05:26 PM

Pete -

I am fascinated and impressed by your explanation. I have a few questions but I wanted to make sure I could not deduce them first. Stay tuned and thanks,


SOLO 07-23-2001 06:13 PM

Juro...hang enough engines on ANYTHING and I can make it fly!
Standing at 11 !?

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