1) Weather
a. Causes- Warm/Cold air mass collisions which cause a low pressure area,
creating warm and cold fronts, and associated weather
i. Warm Front:
1. Warm air riding up over colder air
2. As warm air rises, it cools/condenses
3. Clouds- Cirrus, Cirrostratus, Altostratus, Nimbostratus
4. Rain possible in less than 24hrs
5. Warmer, clearer weather follows
ii. Cold Front:
1. Cold air moving into area of warm air
2. Quicker passage; more severe weather
3. Warm air forced up rapidly, condenses
4. Clouds- Altocumulus, Cumulonimbus, Nimbostratus (Fluffy; Dark)
5. Higher winds, wind direction changes, thunderstorms/line squalls
6. Thunderstorm- High “anvil” clouds, thunder/lightning
7. Line Squall- Higher winds blow top off Cumulonimbus, resulting in low
rolling cloud- look out! (Reef before it’s too late!)
iii. Fog:
1. Warm moist air coming into contact with cold water, or land
2. Might precede a warm front
3. May be in “pockets”, or over large area
b. Weather Signs
i. Barometric Pressure:
1. Rapid rise/fall of 8mb or more- Gale within 4-8 hrs
2. Slower rise/fall of 5mb or less- Strong winds, less than gale force
3. Falling barometer- approaching depression (low)
4. Lower than normal and steady or falling- unsettled weather
5. Higher than normal and steady or rising- settled weather
ii. Clouds:
1. Lower clouds- bad weather
2. Lower clouds (wind), moving at an angle to higher clouds- weather change
3. Back to wind (lower cloud movement):
a. Upper clouds L>R, wx change worse
b. Upper clouds R>L, wx change better
iii. Wind Direction:
1. Wind backing- approaching bad weather
2. Wind veering- approaching better weather
3. Wind at back- Low to your left
iv. Sunsets:
1. Bright yellow- windy
2. Pale yellow- rain
3. Pink- fair weather
2) Wind Scales- Most U.S. weather reports in knots (one nautical mile
per hour)
a. Beaufort Scale-
i. 0- Calm; 0kts; Sea like a mirror
ii. 1- Light air; 1-3kts; Ripples on the water
iii. 2- Light breeze; 4-6kts; Small wavelets- 1ft
iv. 3- Gentle breeze; 7-10kts; Large wavelets, occasional whitecaps- 2ft
v. 4- Moderate breeze; 11-16kts; Small waves, frequent whitecaps- 3ft
vi. 5- Fresh breeze; 17-21kts; Moderate waves, many whitecaps, chance
of spray- 6ft
vii. 6- Strong breeze; 22-27kts; Large waves, white foam crests, probable
spray; 10ft
viii. 7- Near gale; 28-33kts; Sea heaps up, white foam, breaking waves
blown in streaks; 13ft
ix. 8- Gale; 34-40kts; Moderately high waves, spindrift, foam streaks,
18ft
x. 9- Strong gale; 41-47kts; High waves, dense streaks of foam, waves
cresting, breaking; 22ft
xi. 10- Storm; 48-55kts; Very high waves, long overhanging crests; visibility
affected; 29ft
xii. 11- Violent storm- 56-63kts; Exceptionally high waves, wave crests
blown into froth, visibility affected; 36ft
xiii. 12- Hurricane- 64-71kts; Air filled with foam and spray, sea completely
white, visibility greatly reduced, 45ft
b. Coastal Warnings- U.S. Weather Service
i. Small Craft Advisory- Wind and sea conditions dangerous to small craft;
1 red pennant, 1 red over 1 white
ii. Gale Warning- Conditions dangerous to all boats; 2 red pennants, 1
white over 1 red
iii. Storm Warning- Very dangerous conditions; 1 red square flag w/ black
center, 2 red lights
iv. Hurricane Warning- Most dangerous conditions; 2 red square flags w/
black centers, 1 white between 2 reds
3) Where to get Weather Information-
a. AM/FM Radio
b. Newspaper
c. Television
d. Internet- Yahoo!, MSN, etc….
e. Weather Band- Many cars, VHF Radio
f. Telephone- National Weather Service