Some clouds, warm and waterspouts
Good morning Augusta.
This morning it is clear, then partly cloudy. High of 84F. Winds from the
West at 5 to 10 mph.
Tonight it will be partly cloudy. Fog overnight. Low of 57F. Winds less than
5 mph.
The readings from my own instruments are:
The humidity is 87% with a Dew Point of 61.8ºF and a wind chill of 64.1ºF.
The temperature is 65.3ºF.
We have East Northeast winds between 1.0 mph and 2.0 mph.
Our Barometric pressure is 29.89 HPA 1012.1 and falling with a weather
graphic indicating rain.
The UV rating is 1 out of 16, sunset will be at 7:38 PM with Moon Rise at
6:25 p.m. and the moon phase is waxing gibbous.
For the pilots out there, Raw Metar readings are:
METAR KAUG 191053Z AUTO 21003KT 10SM CLR 16/13 A2999 RMK AO2 SLP154
T01560133
Visibility is 10.0 miles/16.1 kilometers with good clear conditions again.
We've had no rain here in the past 24 hours.
Since it is still summer, many near large bodies of water will see
waterspouts. They are similar to, but not identical to tornadoes.
Read these two explanations of waterspouts and you will see what I mean.
From:
http://oceanservice.noaa.gov/facts/waterspout.html
A waterspout is a whirling column of air and water mist.
According to NOAA's National Weather Service, the best way to avoid a
waterspout is to move at a 90-degree angle to its apparent movement. Never
move closer to investigate a waterspout. Some can be just as dangerous as
tornadoes.
Waterspouts fall into two categories: fair weather waterspouts and tornadic
waterspouts.
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.
If a waterspout moves onshore, the National Weather Service issues a tornado
warning, as some of them can cause significant damage and injuries to
people. Typically, fair weather waterspouts dissipate rapidly when they make
landfall, and rarely penetrate far inland.
And copied in whole from USA Today:
Waterspouts are tornadoes over water. But scientific work over the last 30
or so years has led to a more complicated picture with waterspouts differing
in some ways from tornadoes over land, especially large ones.
Waterspouts and all the different kinds of tornadoes have a similar basic
structure with air moving upward. At the ground or ocean surface, winds are
rushing faster and faster as they swirl into the vortex and then upward.
Often with both tornadoes and waterspouts, the vortex is seen coming down
from the cloud, but not obviously touching the ground or ocean. Such
vortices that don't seem to touch the ground are called "funnels" or "funnel
clouds."
It's important to say "seems" not to touch because often, especially in the
beginning, the vortex is invisible along part of its path. We begin to see
the vortex when its lower air pressure cools the air enough to condense
water vapor in the air into tiny water droplets.
Beginning in the late 1960s when he investigated waterspouts in the Keys
from a single-engine Cessna 172 piloted by a friend, Joseph Golden, now a
senior scientist at the National Oceanic and Atmospheric Administration,
documented the "what" of spouts and tried to puzzle out the "why." The
original studies were for his Ph.D. thesis at Florida State University.
During 12 days in September 1974, Golden flew into 16 Florida Keys
waterspouts — one of them 26 times — in a North American T-6 airplane that
had been modified for weather research. The World War II era trainer was
flown by a professional weather research pilot. Golden recalls that flying
into spouts with winds blowing faster than 60 mph around the vortex and
moving upwards at 20 mph or better "rattled my teeth."
And, he notes, these were "weak to moderate" strength waterspouts. Careful
study of movies or videos of waterspouts show speeds up to the 190 mph
range.
They are not to be taken lightly.
In fact, Golden speculates that "a significant fraction of the so-called
Bermuda Triangle incidents are from waterspouts."
How waterspouts form
The first sign, which can be seen from the air but usually not from a boat,
is the formation of a dark spot on the ocean. Smoke flares dropped in these
areas show the air is moving in a circle and upward. Many dark spots die out
without progressing any further. But some begin to take on a spiral pattern
of dark and lighter water.
Golden says at this second stage someone on a boat at the surface would
probably feel the wind shift and maybe increase. Also, if you looked upward,
you might see a funnel coming from a cloud overhead or off to one side.
People on boats will see the third stage.
Even though it might be invisible, a vortex is reaching the ocean surface
from the cloud. When the wind speeds reach around 40 mph, the wind begins to
kick up spray in a circular pattern — the spray vortex. At this time you
might see the funnel pointing down from the cloud toward the ring.
The fourth, or mature, stage is when the funnel reaches all the way from the
cloud to the ocean. You can usually see through the funnel - it's really a
thin cloud of tiny water droplets.
During this stage, small waves are being kicked up and the spout leaves a
bubbly wake behind as it moves across the ocean. These tiny bubbles could be
carbon dioxide and other gases that are dissolved in the water that are
caused to effervesce by the low air pressure in the spout's center - like a
bottle of soda that's just opened.
In the fifth, and final stage, the spray vortex weakens and the funnel
becomes shorter and maybe more tapered. It often twists around and the
bottom of the waterspout may move out from under the cloud.
Scientists say the waterspout's dissipation usually occurs when rain begins
falling from the parent cloud. Cool air brought down by the rain cuts off
the supply of warm, humid air that's feeding into the waterspout to keep it
going.
Where waterspouts are most likely
The Florida Keys "are the greatest, natural vortex lab in the world," says
Golden. "Waterspouts probably occur more frequently in the Florida Keys than
anywhere in the world."
Waters around the Keys, especially from Marathon past Key West on westward
to the Dry Tortugas, probably see 400 or 500 waterspouts a year. Since they
are so common, most go unreported unless they cause damage.
Golden suspects so many waterspouts hit the Florida Keys because the weather
and geography supply two necessary ingredients.
First, the islands and the shallow water along them help heat the air.
During the summer, waterspout season, the air is extremely humid with
temperatures in the mid-80s into the low 90s. The heat causes the air to
rise. As it rises, the air's humidity condenses into the tiny water droplets
that make up clouds.
As water vapor condenses, it releases more heat that makes the air rise even
faster. Rising air currents are needed for waterspout formation.
The second important waterspout ingredient in the Keys seems to be the
regular east or northeast "trade winds" that blow right down the islands.
These winds help line up the clouds. Lines of clouds encourage waterspouts.
Exactly how is one of the questions researchers are trying to answer.
Clouds that spawn waterspouts in the Keys are generally from around to
18,000 to 22,000 feet high. Golden says, waterspouts are likely to form when
the clouds are growing upwards.
In the Keys, waterspouts are most likely to form between 4 and 7 p.m. with a
secondary maximum from 11 a.m. to 1 p.m. A few waterspouts form around
sunrise.
After the Florida Keys, the next most active U.S. waterspout area is the
southeast Florida Coast from around Stuart south to Homestead. Tampa Bay has
the greatest number of damaging waterspouts, probably because the shores of
the Bay are so built up.
Places around the Gulf of Mexico along with the Atlantic Coast northward to
Chesapeake Bay are also likely to see waterspouts. Waterspouts have been
reported on the West Coast from Tatoosh Island, Wash., south to San Diego,
but they tend to be weak and short lived. Waterspouts also skip across the
Great Lakes and Utah's Great Salt Lake from time to time.
Boaters safety around waterspouts
Even though waterspouts are usually weaker than the strong tornadoes over
land, they can be a real danger to boaters. Waterspouts are most common in
the Florida Keys and over other warm oceans, but they can occur over just
about any body of water.
As with any kind of weather hazard, safety begins by staying informed. One
of the special radios that pick up weather broadcasts should always be
aboard your boat. And, you should listen to it regularly.
Waterspouts tend to come from clouds with a dark, flat bottom when there is
just the first hint of rain.
If one heads your way, try to escape by going at right angles to its path.
And if it's about to hit your boat, the best bet might be to dive overboard.
Flying debris is the big killer in tornadoes and waterspouts.
How about diving underwater to escape?
"If you dive before one hits, I think you will be O.K.," says Golden.
But no one really knows what the water is doing right under a waterspout and
such a dive should be a last-ditch attempt to avoid flying debris. I'm not
prepared to say it's safe to dive under a waterspout," Golden says.
This morning it is clear, then partly cloudy. High of 84F. Winds from the
West at 5 to 10 mph.
Tonight it will be partly cloudy. Fog overnight. Low of 57F. Winds less than
5 mph.
The readings from my own instruments are:
The humidity is 87% with a Dew Point of 61.8ºF and a wind chill of 64.1ºF.
The temperature is 65.3ºF.
We have East Northeast winds between 1.0 mph and 2.0 mph.
Our Barometric pressure is 29.89 HPA 1012.1 and falling with a weather
graphic indicating rain.
The UV rating is 1 out of 16, sunset will be at 7:38 PM with Moon Rise at
6:25 p.m. and the moon phase is waxing gibbous.
For the pilots out there, Raw Metar readings are:
METAR KAUG 191053Z AUTO 21003KT 10SM CLR 16/13 A2999 RMK AO2 SLP154
T01560133
Visibility is 10.0 miles/16.1 kilometers with good clear conditions again.
We've had no rain here in the past 24 hours.
Since it is still summer, many near large bodies of water will see
waterspouts. They are similar to, but not identical to tornadoes.
Read these two explanations of waterspouts and you will see what I mean.
From:
http://oceanservice.noaa.gov/facts/waterspout.html
A waterspout is a whirling column of air and water mist.
According to NOAA's National Weather Service, the best way to avoid a
waterspout is to move at a 90-degree angle to its apparent movement. Never
move closer to investigate a waterspout. Some can be just as dangerous as
tornadoes.
Waterspouts fall into two categories: fair weather waterspouts and tornadic
waterspouts.
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.
If a waterspout moves onshore, the National Weather Service issues a tornado
warning, as some of them can cause significant damage and injuries to
people. Typically, fair weather waterspouts dissipate rapidly when they make
landfall, and rarely penetrate far inland.
And copied in whole from USA Today:
Waterspouts are tornadoes over water. But scientific work over the last 30
or so years has led to a more complicated picture with waterspouts differing
in some ways from tornadoes over land, especially large ones.
Waterspouts and all the different kinds of tornadoes have a similar basic
structure with air moving upward. At the ground or ocean surface, winds are
rushing faster and faster as they swirl into the vortex and then upward.
Often with both tornadoes and waterspouts, the vortex is seen coming down
from the cloud, but not obviously touching the ground or ocean. Such
vortices that don't seem to touch the ground are called "funnels" or "funnel
clouds."
It's important to say "seems" not to touch because often, especially in the
beginning, the vortex is invisible along part of its path. We begin to see
the vortex when its lower air pressure cools the air enough to condense
water vapor in the air into tiny water droplets.
Beginning in the late 1960s when he investigated waterspouts in the Keys
from a single-engine Cessna 172 piloted by a friend, Joseph Golden, now a
senior scientist at the National Oceanic and Atmospheric Administration,
documented the "what" of spouts and tried to puzzle out the "why." The
original studies were for his Ph.D. thesis at Florida State University.
During 12 days in September 1974, Golden flew into 16 Florida Keys
waterspouts — one of them 26 times — in a North American T-6 airplane that
had been modified for weather research. The World War II era trainer was
flown by a professional weather research pilot. Golden recalls that flying
into spouts with winds blowing faster than 60 mph around the vortex and
moving upwards at 20 mph or better "rattled my teeth."
And, he notes, these were "weak to moderate" strength waterspouts. Careful
study of movies or videos of waterspouts show speeds up to the 190 mph
range.
They are not to be taken lightly.
In fact, Golden speculates that "a significant fraction of the so-called
Bermuda Triangle incidents are from waterspouts."
How waterspouts form
The first sign, which can be seen from the air but usually not from a boat,
is the formation of a dark spot on the ocean. Smoke flares dropped in these
areas show the air is moving in a circle and upward. Many dark spots die out
without progressing any further. But some begin to take on a spiral pattern
of dark and lighter water.
Golden says at this second stage someone on a boat at the surface would
probably feel the wind shift and maybe increase. Also, if you looked upward,
you might see a funnel coming from a cloud overhead or off to one side.
People on boats will see the third stage.
Even though it might be invisible, a vortex is reaching the ocean surface
from the cloud. When the wind speeds reach around 40 mph, the wind begins to
kick up spray in a circular pattern — the spray vortex. At this time you
might see the funnel pointing down from the cloud toward the ring.
The fourth, or mature, stage is when the funnel reaches all the way from the
cloud to the ocean. You can usually see through the funnel - it's really a
thin cloud of tiny water droplets.
During this stage, small waves are being kicked up and the spout leaves a
bubbly wake behind as it moves across the ocean. These tiny bubbles could be
carbon dioxide and other gases that are dissolved in the water that are
caused to effervesce by the low air pressure in the spout's center - like a
bottle of soda that's just opened.
In the fifth, and final stage, the spray vortex weakens and the funnel
becomes shorter and maybe more tapered. It often twists around and the
bottom of the waterspout may move out from under the cloud.
Scientists say the waterspout's dissipation usually occurs when rain begins
falling from the parent cloud. Cool air brought down by the rain cuts off
the supply of warm, humid air that's feeding into the waterspout to keep it
going.
Where waterspouts are most likely
The Florida Keys "are the greatest, natural vortex lab in the world," says
Golden. "Waterspouts probably occur more frequently in the Florida Keys than
anywhere in the world."
Waters around the Keys, especially from Marathon past Key West on westward
to the Dry Tortugas, probably see 400 or 500 waterspouts a year. Since they
are so common, most go unreported unless they cause damage.
Golden suspects so many waterspouts hit the Florida Keys because the weather
and geography supply two necessary ingredients.
First, the islands and the shallow water along them help heat the air.
During the summer, waterspout season, the air is extremely humid with
temperatures in the mid-80s into the low 90s. The heat causes the air to
rise. As it rises, the air's humidity condenses into the tiny water droplets
that make up clouds.
As water vapor condenses, it releases more heat that makes the air rise even
faster. Rising air currents are needed for waterspout formation.
The second important waterspout ingredient in the Keys seems to be the
regular east or northeast "trade winds" that blow right down the islands.
These winds help line up the clouds. Lines of clouds encourage waterspouts.
Exactly how is one of the questions researchers are trying to answer.
Clouds that spawn waterspouts in the Keys are generally from around to
18,000 to 22,000 feet high. Golden says, waterspouts are likely to form when
the clouds are growing upwards.
In the Keys, waterspouts are most likely to form between 4 and 7 p.m. with a
secondary maximum from 11 a.m. to 1 p.m. A few waterspouts form around
sunrise.
After the Florida Keys, the next most active U.S. waterspout area is the
southeast Florida Coast from around Stuart south to Homestead. Tampa Bay has
the greatest number of damaging waterspouts, probably because the shores of
the Bay are so built up.
Places around the Gulf of Mexico along with the Atlantic Coast northward to
Chesapeake Bay are also likely to see waterspouts. Waterspouts have been
reported on the West Coast from Tatoosh Island, Wash., south to San Diego,
but they tend to be weak and short lived. Waterspouts also skip across the
Great Lakes and Utah's Great Salt Lake from time to time.
Boaters safety around waterspouts
Even though waterspouts are usually weaker than the strong tornadoes over
land, they can be a real danger to boaters. Waterspouts are most common in
the Florida Keys and over other warm oceans, but they can occur over just
about any body of water.
As with any kind of weather hazard, safety begins by staying informed. One
of the special radios that pick up weather broadcasts should always be
aboard your boat. And, you should listen to it regularly.
Waterspouts tend to come from clouds with a dark, flat bottom when there is
just the first hint of rain.
If one heads your way, try to escape by going at right angles to its path.
And if it's about to hit your boat, the best bet might be to dive overboard.
Flying debris is the big killer in tornadoes and waterspouts.
How about diving underwater to escape?
"If you dive before one hits, I think you will be O.K.," says Golden.
But no one really knows what the water is doing right under a waterspout and
such a dive should be a last-ditch attempt to avoid flying debris. I'm not
prepared to say it's safe to dive under a waterspout," Golden says.
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