Thursday, July 28, 2011

Storm Chasing Part 1

Hi, It's Rebecca again, I've been undecided on which topic to write about. I've been playing with the Idea of doing things like: The types of lightning, the different types of clouds, how to forecast the weather, and so on. Those are all great subjects and I will be writing about them in the future.  Something I saw on a video clip yesterday made my mind up. The clip was of two guys taking a video of the tornado that formed in Oneida County Tuesday afternoon. They were heading back to work after lunch; they saw the funnel cloud and since they had a video camera they decided to chase it. They hoped it would give them bragging rights with their friends.  The tornado was only rated an EF0  and most likely because of luck they didn't really get that close; so they were never in any real danger. However, this fact is not the point. As was the case in the Super Dixie Outbreak in April people who have no business chasing storms have close calls all the time; sometimes people who know what they're doing (myself included) make mistakes and get too close. Just because you have a camera doesn't mean you're a storm chaser. It is a very dangerous hobby that can bite if you're not careful. Anyway the topic of my next few blog post will be on storm chasing. During the course of this series, I hope to convey, how to storm spot, how to chase safely, and the equipment needed to chase, and so on.

Before I get started I want to a say, anyone who is even remotely thinking of doing any kind of chasing should take a sky-warn class and read things like my blog entry on  storm structure. Understanding storm structure is the single most Important thing you need to learn, your life could depend on it

Here is a link for a on-line spotter guide.

Why do I chase storms?  I enjoy watching the lightning and hearing the booming thunder in my ears. I could spend hours watching the swirling dark clouds  and feeling the blast of wind on my face. When the weather is bad, you will often find me outside taking pictures or just enjoying the moment.  I have always been fascinated by severe weather,  I saw my first tornado when I was six or seven. I can't remember much about it....But I do remember how excited it made me feel. I still get  this feeling whenever I see a tornado. The feeling is hard to describe, It's wonder, reverence, excitement, apprehension and fear all rolled into one. Even though a tornado is destructive it is also very beautiful to watch. Video doesn't come close to the experience of watching a tornado. The rotating winds, the rush of inflow toward it, The blast of the cold outflow, even the sound are all part of the show.  Every storm is a very unique example of nature's awesome power, no two are ever the same.

As strange as it may sound seeing tornadoes is not the reason most of us chase. Like most, I relish the adventure and challenge of trying to decipher what will transpire; if I'm on my game and very fortunate I will bag one of nature's most elusive creations; if not, I don't really mind, I love to travel to different towns,  meet all the fascinating people, try  restaurants with funny sounding names, and explore different areas of the country. The friendships you form with other chasers are lifelong and strong. When you're chasing you see all kinds of scenery, wildlife, cloud formations, and beautiful sunsets. For me storm chasing is more like a wonderful vacation than it is anything else.

Twister the movie and reality.

 I'm sure most of you have seen "Twister". The movie involves a team of storm chasers darting around Oklahoma during a outbreak. They do lots of stupid things and seemingly finding tornadoes every five minutes.  It's a very entertaining film which I like a lot. However, it really doesn't resemble reality. The movie gives the impression that you can run away from a large tornado and live to tell the tale by tying yourself to a few pipes in the ground. If you tried that, the least that would happen , you would most likely be severely hurt by flying debris.  My biggest pet peeve is how the movie showed tornadoes forming from stratus clouds out of a clear blue sky; you could also see blue sky in the same shot as the tornado. In reality this would never happen. In the case of the F5 tornado at the end of the movie, the sky is brilliant blue right next to the tornado. Also, the tornado dissipates way too quickly.  When in reality An EF5 would form from a very large supercell which would make the sky very dark. As for the second point, when a large wedge tornado dissipates it normally does so in stages ending in the rope stage just before it lifts off the ground.

In my next blog post, I will tell you some storm chasing rules. What a typical chase day is like, and a little about Klingons and why chasers hate them.

Thanks for reading,
Rebecca Ladd

Saturday, July 23, 2011

Heat Advisory for the Hudson Valley south of Albany
Today expect some sct'd storms even tonight along with hot & humid weather. Relief then follows tomorrow through Tuesday with near or slightly warmer than normal temperatures (but NOT hot) & more comfy conditions.
The humid weather returns by Wed; it will be very warm & muggy Thurs & Fri and possibly into to start of next weekend.
As far as temps go using blend of data (operational models and ensembles) I would say no heat wave but next Th and Fr could be upper 80s to 90 with Fr having the best chances for being the hottest day (some low 90s possible).

Wednesday, July 20, 2011

It's NOT the humidity it's all about the Dew Point!

More than a few people have a tough time understanding the difference between the meaning of relative humidity (RH) and dewpoint  (DP). So, Rebecca and I thought we would write a short discourse on the difference between humidity and dew point:
Dew point is also called the saturation temperature. It tends to be a better indicator of moisture in the atmosphere. Changes in dew point temperature reflect changes in the moisture content of the air.
The higher (lower) the DP the more (less) moisture in the air. DP's in the 60s or more indicate very moist air. DPs in the 50s or less indicate dry air. Since dew point is the saturation temperature of the air, when the DP temperature is reached, the relative humidity is 100%.

Here is a general summertime guideline for dew points...
Below 50: very dry
50-59: comfortable
60-64: moderately humid
65-69: very humid
70-79: oppressive
80: forget it and stay in bed.

Humidity is relative to changes in the air temperature. As it warms the humidity goes down, as it cools the humidity goes up. Here's another way to explain it: if the RH is less than 40%, it will feel dry outside. On the other hand, when the RH is greater than 80% it feels moist outside. The question is how moist, this is where dewpoint comes in. The DP will determine if it is uncomfortably moist or just regularly moist. Generally, as long as the temperature is comfortable the RH feels comfortable, as long as RH is Between 40 and 80%. 
Here's an example: Let's say the air temp and dew point are 60 degrees then humidity is 100%. Now let's say the air temp goes to 80 degrees and the dew point stays at 60 then the humidity is 50%
This is why dew point is a better gauge of how comfortable or uncomfortable a day in summer is.
The heat index (HI) combines air temperature and dew point yielding an apparent or "feels-like" temperature. The HI is to summer what the windchill factor is to winter. The body cools down when it perspires and this "sweat" evaporates. When the HI is high it means there is a lot of moisture in the air. The more moisture in the air then evaporation is slower or decreased, thus when you perspire, if the HI is very high it becomes more difficult for your body's "sweat" to evaporate and therefore it becomes more difficult for your body temperature to stay cool. If our internal body temperature starts to rise during hot and humid weather this can lead to an assortment of heat related illnesses. Here is an overview of heat related illnesses: Types of Heat related Illnesses
An Excessive Heat Was has been issued by NWS for the lower elevations of Eastern NY State and Western New England for Thursday afternoon through Friday night. The Heat Index may rise to between 100 and 110 degrees tomorrow afternoon and again on Friday afternoon!

So remember to drink plenty of water...also remember the hot weather safety tips mentioned here Severe Weather Safety

Friday, July 1, 2011

Severe Weather Safety

Hi, it's Rebecca again, I wanted to close my blog series with severe weather / tornado safety. Not only did I want to  write about warnings and watches, but also about a passion of mine, That passion is tornado safety. I always jump at the chance when asked to speak about the subject. So without further ado let's dive in.

You've heard the WTEN weather team mention them, but what do the alerts mean, and what should you be you do when they're issued. When severe weather is imminent, the National Weather Service (NWS) will issue different watches and warnings, each watch or warning requires you to take different actions. But, what exactly is the difference between a severe weather watch and warning? And what about an advisory?
Severe Weather watches and warnings what's the difference?

An advisory alerts you to weather conditions that are likely to happen or happening and could cause an inconvenience or difficulty for travel or other outdoor activities.

A watch means that severe weather is possible within the coming hours. This alerts you that the chance of dangerous weather is on the way, it's issued to give you time to formulate a plan of action in the case that conditions get worse.

A warning implies the imminent threat of severe weather including such things as:  severe thunderstorm, tornado, or flash flood. When a warning is issued, either the National Weather Service has directly observed or detected the storm on radar. Warnings are only issued when the danger is dire and about to hit your doorstep. You must take immediate safety measures to protect your property and the lives of your family and yourself. I know life can get hectic at times. But, never ignore a warning.

To sum it up:

An advisory means you might be inconvenienced.

A watch means be on the lookout it might get worse..

A warning means take action.
Let's take an in-depth look at the type of alerts you're most likely to encounter during the Summer.


Flood and Flash Flood Watches

What It Means:

A flood or flash flood is possible.

What To Do:
  • Listen to the radio or TV for weather updates.
  • Be ready to respond and act immediately.
  • Be alert to signs of flooding. If you live in a flood-prone area, be ready to evacuate at a moment's notice.
  • Follow the instructions and advice of local authorities.

Flood and Flash Flood Warnings

What It Means:

Flooding or flash flooding is already occurring or will occur soon.

What To Do:
  • Listen to the radio or TV for weather updates.
  • If you live in a flood-prone area or think you are at risk, evacuate immediately.
  • Move quickly to higher ground. Save yourself, not your belongings.
  • Follow the instructions and advice of local authorities.
  • If advised to evacuate, do so immediately.
  • Follow recommended evacuation routes.
  • Leave early enough to avoid being marooned by flooded roads.
  • Avoid flooded roadways. Two feet of water will carry away most automobiles.

Heat Advisory

What It Means:

There is an extreme heat index between 105 °F to 115 °F for up to three hours during the day and at or above 80 °F at night for two consecutive nights.

What To Do:
  • Never leave children or pets alone in closed vehicles.
  • Slow down. Avoid strenuous activity.
  • Take frequent breaks if you must work outdoors.
  • Postpone outdoor games and activities.
  • Stay indoors as much as possible.
  • If your home does not have air conditioning, go to a public building with air conditioning each day for several hours.
  • Wear loose-fitting, lightweight, light-colored clothing that covers as much skin as possible.
  • Drink plenty of non-alcoholic fluids even if you do not feel thirsty.
  • Frequently check on animals

Severe Thunderstorm Watch

What it Means:

Conditions are conducive to the development of severe thunderstorms in and close to the area. A severe thunderstorm produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.

What to Do:
  • Listen to the radio or TV for weather updates.
  • Get away from natural lightning rods such as golf clubs, bicycles and camping equipment.
  • Be prepared to seek shelter if a severe thunderstorm approaches.

Severe Thunderstorm Warning

What It Means:

Spotters have observed a severe thunderstorm or it has been indicated on radar, and the storm is occurring or imminent.

What To Do:
  • Close any open windows and close your drapes or curtains.
  • Unplug appliances and turn off the air conditioner.
  • Avoid taking a bath or shower, or talking on a corded phone.
  • Take shelter in substantial, permanent, enclosed structures. If there are no reinforced buildings in sight, take shelter in a car..

I want to add, there is no such thing as a lightning warning. However, that doesn't mean it's not dangerous.  In fact, in the U.S each year lightning kills around 60 people and injures hundreds. If you hear thunder you're close enough to be struck. Generally speaking, being within 10 miles of the storm’s epicenter puts you at an elevated risk of experiencing lightning.    however this is rare. The safest place in a thunderstorm is inside a sturdy building. Stay away from windows, stay away from anything that is "plugged in" and plumbing. A hard-topped vehicle is acceptable if you are unable to reach a building.
What to do if you're outside with no shelter. I love to hike and horseback ride, so if you're like me you're outside a lot. I want to be clear, there is no safe place outdoors during a thunderstorm. The following tips will lessen the odds of being struck, but not make them zero. In general, you don't want to be the tallest object in the area. So, avoid open fields, the top of hills, and isolated trees or other tall objects.
If your camping, don't setup your camp on a hilltop; instead choose a valley or other low area. (But be mindful of where the flood plain is). Remember, a tent offers no protection from lightning, If your car or other sturdy building is nearby run for it before the storm arrives.
If your hiking and feel your hair stand on end (lightning is about to strike you or very close to you), squat down on your haunches, onto the balls of your feet and put your hands on your knees. (the lightning crouch). Do not lie flat on the ground; the idea is to reduce both your height and ground contact.

A thunderstorm is dangerous to boaters, swimmers, and those near the water on land. Whenever you see lightning or hear thunder you should get away from the water and go to a building or vehicle with a metal top. In case you're wondering, a picnic-type shelter is not a safe place.

If you're on a boat. The first thing you should do is, at the first sign a storm is brewing get the boat to shore as quickly as possible. However, that's not always possible;  if you're caught in a thunderstorm take these actions.

1) Get swimmers out of the water.

2) Stay away from the electronics.

3)Lower antennae, outriggers, and flagpoles.

4) If there's a cabin, go below decks. If you don't have a cabin get in the middle of the boat and stay low.

If you're swimming at the beach / swimming pool. Swimming during a thunderstorm is one of the most dangerous things you can do. Get out of the water at the first sound of thunder.  There is a technique called the Flash-To Bang (F-B). It gives you a rough idea how far away a storm is. It measures the time from seeing lightning to hearing associated thunder. If you count from 1 to 5 (one thousand one, one thousand two, ....) from F-B, lightning is one mile away. The National Lightning Safety Institute recommends getting out of the water when the F-B count is thirty. But I still go by the rule...If you hear that thunder sound don't stick around. You should wait at least 30 minutes after the storm as passed before resuming swimming activities. 
As a seasoned horse owner and rider, I can tell you late spring, summer, and early fall can bring storms you may not be prepared for. Whenever you are out and about with your horse. If you notice that a storm is brewing, do not waste any time go find an adequate shelter. If in spite of your precautions you are caught in the open during a lighting storm, the very first thing you need to remember is to get off the horse. While you cannot outrun lightning, you are able to stay low and decrease your likelihood of getting hit. Stay out of river beds and off hills, and instead seek out the lower part of slopes of hills. Tie your horse to a bush – never a tree – and get into the lightning crouch. Wait out the storm and ride home after it has passed.

Tornado Watch

What It Means:

Conditions are favorable for the development of severe thunderstorms and multiple tornadoes in and close to the watch area.

What To Do:

  • Keep an eye on the sky and listen to the radio or TV for weather updates.

Tornado Warning

What It Means:

A tornado has been sighted by spotters or it has been indicated on radar, and is occurring or imminent in the warning area.

What To Do:
This is where I want to diverge from the normal list of things to do. Instead, I'm going to start with an imaginary tale, to set the mood. and then tell you what you should do.
Imagine, you're  awakened from a sound sleep by soft pinging on the window;  in the distance you hear a little thunder ; you get up and go over and look out the window, you see it is just a little hail. So you go back to bed with the pinging and the soft sound of thunder in your ears. However, your sleep doesn't last long, in about an hour you're awakened again, this time to a loud roar and the sound of stuff hitting your house. You are about to come face to face with natures most terrifying creation... the tornado... If you're ever in this situation it's not the time to ask, what am I supposed to do?  This blog post is about what you can do to keep you and your family safe.

When a tornado is bearing down on you there is no such thing as guaranteed safety. However, a little planning along with a few safety tips can greatly increase your chances for survival.

The most important piece of advice I can give you is Plan, Plan, Plan. Just like you have a home fire evaluation plan, you should have a tornado shelter plan. Your tornado shelter plan will be based on what kind of dwelling you live in. Also, know the signs of an impending tornado.

The first thing to do when a tornado watch is issued, think about the drill and make sure your safety supplies are where you think they are. Turn on your TV, radio or NOAA weather radio and stay alert for warnings. If you don't have a NOAA weather radio, get one, they don't cost much and can save your life.

Signs of a tornado:

This blog series has been about weather identification and awareness. It's important to know what's heading your way. As for tornadoes, I've said be on the lookout if you see such things as:

1)  The cloud base has a strong and persistent rotation.

2)  A lowering in the cloud base.

3)  whirling dust, smoke, or debris under a cloud base....remember tornadoes don't always have a visible funnel at first.

4)  A black or dark green cloud base. while this doesn't mean you're going to have a is another sign.

5)  A loud, roar, rumble, or other loud sound, which doesn't stop after a few seconds.

6)  At night if you see  white-blue-green flashes, those flashes are  power lines and transformers being knocked down by strong winds,  most likely a tornado.  

Plan ahead to stay alive:

Like I said above, a family tornado plan is important. But having a plan is not enough, your family has to practice it at least once a year. Also, have a predetermined place to meet after the tornado has passed (tell your friends, neighbors, and family where it is). The greatest single danger in a tornado is flying objects; you want to have as much protection between the tornado and your family as you can get. Therefore it's a good idea, to have pillows, blankets, sleeping bags,  or a mattress in or very near your shelter space, ready to use.  

If your house has a basement, go to it and take shelter under a heavy table, workbench, or get in under the stairs. Also know where the refrigerators, freezers, and all other heavy objects are above you. Believe me you don't want to be under them, they may fall through a weakened floor. It never ceases to amaze me how many people think they should open the windows before a tornado hits. They believe it will help equalize the pressure. The only thing opening your windows will do is waste your time. So don't worry about the windows, the tornado will take care of that for will need every second to get to safety.

If your house doesn't have a basement. Go to a  closet or bathroom on the lowest floor of your home. If you can't make it to them get into a interior hallway  away from windows. When you have found as safe a place as you can; crouch down as low as possible to the floor, facing down; and cover your head with your hands. And remember, if your house is hit by the tornado there's a good chance the roof and walls will come down, this is where the before mentioned pillows or mattresses come in.

If you're in a mobile home, I can't emphasize this enough GET OUT,  you are most likely safer outside, even if it's tied down. So get out and go to a sturdy permanent building that's close by. If  no place is available, go to a ditch or low area of ground and  lie flat, protecting your head. The spot should be away from your home, car, and trees. Because, these could easily be blown on top of you.

What to do if you're in a motor vehicle. If you're about to come face to face with a tornado being in a car or truck is the last place you what to be.

As you can see a car or truck is no match for a tornado. Trying to out drive a tornado is extremely dangerous. The decision to try is strictly a personal one. Tornadoes can move at speeds greater than 60 mph. What looks far away can be on top of you before you know it.  If you see a tornado while driving that looks far away, and the traffic is light, you may be able to drive out of its path by moving at right angles to the tornado. However, if it's close, you should get your car off the road. Get out and quickly seek shelter in a sturdy building. If  you're in open country, run to low ground away from any cars, lay flat and protect your head.
About hiding under bridge underpasses. In one word DON'T. Tornadic winds are stronger under a bridge, this is because of a wind tunnel effect known as wind channeling. The problem is that you're trapped but still outside. If the tornado hits the bridge that you're under you will get hit with everything it's carrying. Cars, rocks, boards, exc. But one type of debris  is often overlooked is dirt.  Dirt can act like a sandblaster in tornadic winds.

                                    Image courtesy of Dan Miller NWS Norman, OK

In the above image a few people took refuge under this bridge underpass. The red outlines are from dirt blown around them by the tornado.  They were hit by such things as dirt, branches, rocks, you name it. They thought the underpass would be a place of safety, they were wrong, no one survived.
Another underpass incident I know about; a women tried to take shelter up in the girders of the underpass, her body was later found about a quarter of a mile away.

The idea of hiding under a bridge underpass started from a famous video from 1991. where a bunch of people get up under there and they're fine. It turned out that the tornado didn't actually hit the bridge, but went off to the side a bit, which is why they were fine. 

Let me say it again, During a tornado it's NEVER safe to be under a bridge. In fact, that is perhaps more dangerous than standing out in the open.
You may have noticed that I keep saying get as low as possible; that's because in a tornado winds get stronger with height. so even if the depression is only a few feet deep, it can be enough to get you below the wind field enough to survive....Objects will be flying around so It may hurt.....but it will be better than the alternative.
The following links have additional severe weather and tornado safety information .
The first is from NOAA, it deals with underpasses.
Here is a link to a slide show from my alma mater Texas A&M. It covers what to do and what not to do during a severe weather event.


Well that's about it...I've enjoyed writing this blog series, I hope you have enjoyed reading it.

Rebecca Ladd