Showing posts with label National Flood Insurance Program. Show all posts
Showing posts with label National Flood Insurance Program. Show all posts

Wednesday, June 26, 2013

The Anatomy of Waterspout

Waterspout:  waw-ter-spout (noun) A tornado occurring over water that forms a column of water and mist extending between the surface and the clouds above. cyclone, twister, whirlwind, eddy


5 Part Life Cycle 
 Stage 1: Formation of a dark spot on the water surface
Stage 2: Spiral Pattern on the water surface
Stage 3: Formation of a spray ring
Stage 4: Development of visible condensation funnel
Stage 5: Ultimately decay



Two types of Waterspouts: Fair Weather waterspout & Tornadic waterspout

Tornadic waterspouts are tornadoes that form over water, or move from land to water. They have the same characteristics as a land tornado. They are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning.


Fair weather waterspouts usually form along the dark flat base of a line of developing cumulus clouds. This type of waterspout is generally not associated with thunderstorms. While tornadic waterspouts develop downward in a thunderstorm, a fair weather waterspout develops on the surface of the water and works its way upward. By the time the funnel is visible, a fair weather waterspout is near maturity. Fair weather waterspouts form in light wind conditions so they normally move very little. These type of  waterspouts dissipate rapidly when they make landfall, and rarely penetrate far inland.

Boaters: If a waterspout is sighted, immediately head at a 90 degree angle form the apparent motion of the waterspout. Never try to navigate through a waterspout. Although waterspouts are usually weaker than tornadoes, they can still produce significant damage to you and your boat.
*An amazing fact about water spouts is that they continue to be mysterious despite of extensive 
studies on them. Their unique nature continues to baffle world all together.

 A bit of history...
Waterspout3
Physical and Meteorological Observations: Conjectures and Suppositions by Franklin in 1751 , but not published in the Royal Society's Philosophical Transactions until 1765 , Franklin explained a weather condition that forms large "whirlings". “Thus these eddies may be whirlwinds at land, waterspouts at sea.” He assumed that these were produced by air ascending or descending that had attained a circular motion. The air within receded “from the middle of the circle by a centrifugal force, and leaving there a vacancy; if descending, greatest above, and lessening downwards; if ascending, greatest below, and lessening upwards; like a speaking trumpet standing its big end on the ground. When the air descends with violence in some places, it may rise with equal violence in others, and form both kinds of whirlwinds.The air in its whirling motion receding every way from the center or axis of the trumpet, leaves there a vacuum; which cannot be filled through the sides, the whirling air, as an arch, preventing; it must then press in at the open ends. …. The air entering, rises within, and carries up dust, leaves, and even heavier bodies that happen in its way, as the eddy, or whirl, passes over land. If it passes over water, the weight of the surrounding atmosphere forces up the water into the vacuity… A body of water so raised may be suddenly let fall, when the motion, &c. has not strength to support it, or the whirling arch is broken so as to let in the air; falling in the sea, it is harmless, unless ships happen under it. But if in the progressive motion of the whirl, it has moved from the sea, over the land, and there breaks, sudden, violent, and mischievous torrents are the consequences.”


*The earliest record of a water spout on sea goes as back as 1456 when a whirlwind of water was spotted on the sea near Ancona in Italy

Wednesday, June 19, 2013

The Anatomy of a Hurricane


Hurricane: hur·ri·cane (noun)
1. A storm with a violent wind, in particular a tropical cyclone in the Caribbean. 
Synonyms: storm-tornado-gale-tempest-typhoon-whirlwind



Facts: 
¨ On average hurricanes are about 300 miles wide although they can vary in size.
¨ The eye at a hurricane's center is a calm, clear area around 20-40 miles across.
¨ The “eye wall” surrounding the eye is composed of dense clouds that contain the strongest winds in the storm.
¨ The storm's outer rain bands are made up of dense bands of  thunderstorms They range a few miles to tens of miles wide and 50 to 300 miles
¨ Hurricane-force winds can extend out to about 25 miles in a small hurricane and to more than 150 miles for a large one. Storm-force winds can stretch out as far as 300 miles from the center of a big hurricane.
¨ Usually, the right side of a hurricane is the most dangerous in terms of storm surge, winds, and tornadoes.
¨ A hurricane's speed and path depend on ocean and atmospheric interactions, including the presence or absence of other weather patterns. This complexity of the flow makes it very difficult to predict the speed and direction of a hurricane.
¨ Do not focus on the eye or the track–hurricanes are immense systems that can move in complex patterns that are difficult  to predict. Be prepared for changes in size, intensity, speed, and direction.


Safety Tips:.
Pre-Season
  • Enter the season prepared.
  • Know all evacuation routes if you live close to the coast.
  • Make sure your home meets building codes for withstanding hurricanes, and they have storm shutters.
  • Have proper tools, supplies, and a first aid kit.
  • Have plenty of batteries and flashlights
  • Always have plenty of non-perishable foods on hand.
Watch or Warning in effect:
  • Leave low lying areas.
  • Protect windows with plywood boards, or storm shutters.
  • Secure outside objects.
  • Make sure you have plenty of fuel and water.
  • Have several days supply of food and water for each family member.
  • If called to evacuate, do so immediately.
Before the storm
  • Be ready to put your plan and preparation into action.
  • Pay attention to local weather reports on radio, television, or the internet.
  • Have house boarded up, or have storm shutters in place.
  • Have plenty of food and water.
  • Make sure all your tools, supplies, and first aid kit available for use.
  • Have a secure room available.
During the storm
  • Stay in Secure Room.
  • Stay away from windows.
  • Do not use the phone, or candles.
  • Monitor Weather and Civil Service Bulletins on either regular or NOAA radio.
  • Have supplies on hand.
  • Remain indoors when the eye moves over your area because the storm will resume shortly.
After the storm
  • Make sure that all is definitely clear outside, and the storm has completely passed before going out.
  • Report downed power lines, and stay away from them.
  • Use stored water and food.
  • Be patient. Things will take a while before they get back to normal.