More Derecho lessons...

As described yesterday, at the end of June the Eastern states were hit by a rare summer storm of strong, sustained winds blowing from the West. It produced hurricane force winds that gusted as high as 91 miles per hour in Fort Wayne, Indiana. Trees fell everywhere and the damage was massive. Here's some comments from a reader of SurvivalBlog.com

We here in West Virginia are used to disasters such as floods but the mountains tend to shield us from tornados and high winds are rare. Within an hour span[,] power was knocked out to 50 of the 55 counties in the state. The towers of major transmission lines were twisted wrecks.   [...]

· Gasoline was gone within 24 hours. Lines were just like the 1970s fuel embargo.
· Ice became the chief commodity and was in short supply or no supply.
· Water was out for most people at least for the first two days.
· Most big box stores and gas stations were up on generator power by day three.
· A new shipment of 250 generators was sold in a few hours. [...] 

 With all traffic lights out it was hectic but for the most part people were safe and courteous.  [...]  

The local radio station stepped up to the plate and suspended normal programming and went live 24 hours on generator with news and call-ins giving information. The unpreparedness of some of the call-ins was instructive. On the second day several were screaming for FEMA to arrive.

Dude, where's my electricty?

On June 29, the Atlantic coast was hit by a rare "derecho", a powerful wind storm that blows in from the Midwest and out to the Atlantic Ocean.  The storm and following heat wave without power has killed at least 23 people; some died when trees fell on their homes and cars, and heat stroke killed others.

In the U.S. we take electricity for granted and assume any outage will be brief. But five days after the deadly storms, there were still 1 million homes and businesses in a swath from Indiana to Virginia that remained without power. In Virginia alone emergency crews worked around the clock to deal with 60,000 outages.

Long duration outages like this occur after wind or snow storms bring down hundreds of thousands of trees on power lines.  With 3000 workers in Virgina and West Virginia combined, each person may have 40 lines to locate the break and fix.

"This was not a storm where tree limbs just fell on our wires," [Pepco spokesman Clay Anderson] says. "This was a storm where large mature trees were uprooted and lifted and just thrown into our poles — snapping our poles in half and wrapping our high-voltage wires around homes, businesses and cars."

You might say, bring in outside help, but that's exactly the problem with large regional storms. Your neighboring states are in just as bad shape and have no one to spare. So you have to ask for help from far away that will take a day or two to arrive.

Bottom Line:

Be prepared with a week of food and water and light. 72-hours is just not enough.

How long does it take to get Frostbite?

How long does it take to get frostbite? Sounds like an easy question but I find many different answers on the Internet (including one tough old New Englander who answers, "never", with proper clothing). Part of the confusion lies in the definition of "Wind Chill". See http://perpetualpreparedness.blogspot.com/2010/01/wind-chill.html for details. There have been two changes.

1st:  In Nov. 2001 the wind chill values were changed based upon a new equations, see http://www.crh.noaa.gov/ddc/?n=windchill. Whereas 15°F used to be extreme cold in 20mph wind, now it's "safe" at all wind speeds and never drops below -11 wind chill.

2nd: Some revised charts appear to use the new wind chill values but kept the color bands the same for exposure times. See this NOAA chart from 2010 which still has 15°F freezing within 5 minutes with strong wind. http://www.srh.noaa.gov/jetstream//global/chill.htm

A new NOAA chart from 2011 (pictured above) updates the color zones. http://antarcticfudgesicles.wordpress.com/afsa-student-page/how-long-does-it-take-to-get-frostbite/ The exposure time colors don't exactly match the wind chill numbers anymore (for instance -40 wind chill is in two different color zones).
Wind chill of -20°F to -35°F (approx) Frostbite in 30 minutes for exposed face, at night.
Wind chill of -35°F to -50°F (approx) Frostbite in 10 minutes.

There used to be a -30-30-30 rule that -30°F with a 30 mph wind could freeze skin solid in 30 seconds. Under the new chart it's -30 & 30mph & 5 minutes for frostbite.

Bottom Line
So what happened to the NOAA charts? During the fall of 2000, the Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM) organized a joint U.S.–Canadian government-sponsored action group to develop, test and implement a new Wind Chill Temperature Index. Human trials were done in Toronto, Canada with 12 volunteers in chilled wind tunnels with thermal transducers stuck to their face while walking on a 3mph treadmill. Brrrrr.

So the new chart is based on solid human evidence of facial skin instead of mathematical modes and time to freeze bottles of water.  See http://www.nws.noaa.gov/om/windchill/images/wind-chill-brochure.pdf for more information.

Wind Chill

"I've got to go home - Oh, baby, you'll freeze out there
Say, lend me your coat - It's up to your knees out there"
- song lyrics from Baby It's Cold Outside

Slate.com recently published an article, "It's time to get rid of a meaningless number", that is opposed to the idea of "Wind Chill factor". The columnist believes that "no amount of tweaking will make wind chill more comprehensible."

Let's start at the beginning. In 1945 two Antarctic explorers, Paul Siple and Charles Passel, realized that a bottle of water would freeze faster on a windy day than on a calm day. This is because the wind is more efficient at carrying away the heat in the water. They carefully recorded wind speed and freezing times to create a chart and formula uniting wind and temperature. So given 5 F and a wind speed of X, you could calculate that a bottle would freeze in the same amount of time as a calm day of -40 F.

The concept of wind chill was first used by Canadian Weather men in the 1970s. The Siple-Passel formula was used for 30 years before two researchers, Randall Osczevski in Canada and Maurice Bluestein in the United States, decided to retest the numbers. They found that the Siple-Passel formula was too extreme in its predictions. So instead of -40F above the same 5F and wind would feel more like -19F.

So this is confusion #1 - the system of wind chill was changed at the turn of the century.

Confusion #2 - If it's a windy day at 35F, the wind chill might "feel like" 20F but no bottle of water (or anything else) is going to freeze. The coldest anything can get in this example is 35F - safely above freezing. All wind chill does is tell you how quickly you'll cool down to the outdoor temperature - not how cold you will become. Wind does not make things colder than the air temperature - it just makes them as cold, faster.

Confusion #3 - Your results may vary. The actual rate at which your body cools will depend upon the clouds & sun, how much skin you have exposed, how insulating your coat is, how exposed you are to the wind, and so on. The modern Wind Chill model is based upon people who are 5 feet tall, somewhat portly, and walk at an even clip directly into the wind.

Bottom Line

Wind Chill is useful as a reminder about the dangers of a cold wind but keep in mind the limitations mentioned above. Also remember that wet clothes draw out heat and will cool you down faster than dry clothes. Stay dry and out of the wind.

Check out one of my early blogs for more details on Hypothermia.

When Sand Attacks

“If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand”- economist Milton Friedman

Today’s blog post will let pictures do most of the talking. On September 23 Sydney, Australia, suffered its worst dust storm in 70 years. Wild winds swept millions of tons of red dust from the continent's drought-ravaged interior and dumped it on coast. Residents woke up to a “hellish” red sky. The thick air cut visibility to less than 100 meters delaying or canceling flights, ferries, and most forms of pubic transportation. Workers and commuters choked on the dust and emergency departments were flooded with calls. Sydney's air is expected to remain choked with particles for up to three days.

Bottom Line

Dust storms were not something on my preparedness radar before. But sand and dust can travel a long ways. The ash from Mt. Saint Helens traveled many hundreds of miles. Fine sand from the Sahara in Africa blows across the Atlantic and endangers coral reefs in the Caribbean.

What to do in a dust storm? Stay at home, seal all windows facing the wind (but allow some fresh air into the house from the sheltered side), and have a supply of face masks on hand. Protect your eyes and ears from sand. Do not travel alone.

http://www.justincasearizona.com/be-informed/natural-disasters/dust-storms.asp
http://www.wikihow.com/Survive-a-Dust-Storm-or-Sandstorm

Wind Speeds

“I can't change the direction of the wind, but I can adjust my sails to always reach my destination.” - Jimmy Dean

As a sail boater, it’s important to understand the wind. Too little and the day is wasted. (Once there was more tide than wind and our boat floated backwards despite full sails.) Too much and the sailing is dangerous. (Our town’s club boats are mostly tip-proof but when winds tilt the boat over 45 deg. and the gunnel (deck edging) is in the water then it’s time to return to port. Racers & youth might enjoy this but I don’t.)

For those of us who don’t carry a wind gauge or anemometer in our pocket, the classic way to measure the wind is via the Beaufort Wind Scale. The scale was created in 1805 by Sir Francis Beaufort, a high-level administration in the British Royal Naval to standardize just what was meant by “a stiff breeze” and other wind speed comments in the ships’ logs. The system was adopted by the Royal Navy in 1830.

The advantage of this scale is that you can look at the waves, trees, and flags to estimate wind speed. Today for example, flags are partially extended so it’s a Light breeze and a great day to sail.

Since I can not paste an HTML table into this, please check out the NOAA version of the Beaufort scale for actual details.

Bottom Line

I can never remember each of the 13 steps in the Beaufort scale. What I have learned is key indicators:

• If flags don’t flap then it may not be worth going out on the water (or flying a kite)
• Many white caps means small boats should get out of the water
• It takes a lot of wind to move most trees (quaking aspens being the exception)
• It does not take much wind to stir up the seas. Small craft advisory now begins at 17 knots, but it takes 30 knots for a Gale, 48 for a Storm and 64 for a Hurricane.

Hypothermia

"Never such a blizzard before"
- from the song Baby it's cold outside

Hypothermia describes the rapid, progressive mental and physical collapse caused by the chilling of the inner core of the human body. It is the number one killer of outdoor recreationalists who simply can't believe that temperatures between 30 and 50 degrees can be dangerous. When dry and covered you might survive 30 degree air. But swimming in 50 degree water can be deadly and when your clothes are wet in fifty degrees air, the cold water running down your neck and legs quickly robs body heat. A blowing wind will go through and under wet clothes, evaporating water on your skin, causing a refrigeration effect.

I'm quite impressed by the site http://www.adventuresportsonline.com/skihypo.htm which provided the hypothermia information above. It also charts comparing water temperature to survival times, signs of hypothermia, what to do, and more.

From eMedicineHealth I learned that Hypothermia has been a military problem ever since Hannibal lost nearly half of his troops while crossing the Pyrenees Alps in 218 B.C. It has continued to plague military campaigns through both world wars and the Korean War.

Bottom Line

Uncontrollable or violent shivering is a warning sign of early stage hypothermia. Shivering can double heat generation for a few hours. But eventually fatigue sets in, and the body exhausts its fuel stores. As your core body temperature drops, cold reaches the brain depriving you of good judgement and reasoning power. You will not realize this is happening. You will lose control of your hands, then your body, and eventually die.

Seek help immediately while you still have the energy, the muscle coordination, and the common sense to reach help. However if you're lost don't wander at random hoping to be rescued; seek shelter instead. Once sheltered, take off wet clothes and replace with dry if available. Refuel your body with food and water. Do NOT consume alcohol, caffeine or tobacco. Build a fire. Get inside a sleeping bag if available. If you're not alone, huddle with others to share body heat.

For more details see also the Outdoor Action Guide.