All posts by Jim Woodmencey

Be Lightning-Safe this Summer

From fishing, boating, hiking and climbing, to softball, soccer and golf, summertime activities can frequently expose us to the dangers of lightning.

Knowing the dangers and what to do if caught outdoors in a thunderstorm, may help you avoid being zapped this summer. So, as I do every year, I’ll review some lightning safety tips for you in this week’s column.

Electrical Casualty

Your standard household electrical outlet carries 120 volts of electricity. A single lightning bolt can generate up to 100 million volts of electricity, for a micro-second.

The temperature of a lightning bolt, during that split second, can reach 54,000-degrees Fahrenheit, which is about five times hotter than the temperature on the sun.

The electrical energy and intense heat from lightning can hurt you in a number of different ways:

1) Direct Strike. This rarely happens, however, if you were unlucky enough to take a direct hit, it would be game-over, right then and there.

2) Conduction. Electrical energy travels through all metal objects, but also through graphite, carbon-fiber and water. During electrical storms avoid direct contact with wire or chain-link fences, your fishing pole, hiking poles, bicycle or boat. Think of sticking your finger in a light socket, multiplied by about one-million times.

3) Side-flash. The heat & electrical current that emanates outward through the air from a nearby lightning strike can cause cardiac arrest, concussive injuries, severe burns and/or nerve damage.

4) Ground Currents. When lightning strikes the ground, the electrical current is carried outward, radially, in all directions through the ground. If that current reaches you, where you are standing or sitting, it can travel through your body. Cardiac arrest, burns and nerve damage are all possible from ground current.

Direct hits and conduction account for about 20-percent of all lightning casualties. Side-flash accounts for about 30-percent. Ground currents are the most common way people are injured or killed by lightning, accounting for 50-percent of the casualties.

Safest Retreats from Lightning

The safest place to be during a thunderstorm is in a building or a car. A “building” means a 4-walled structure with a foundation and grounded electrical and plumbing. A picnic shelter or large tent may keep you out of the rain, but your lightning exposure is the same as standing out in the open.

It is not the tires on your car that insulate you, it is actually the metal frame and body of the car that dissipate the electrical energy around you. A motorcycle or bicycle do not offer this same “halo” of protection.

If there is not a building or car to retreat to, get to lower ground. Get off ridgetops, off the water, if you can, get to a grove of similar height trees to wait it out. Do not run for the biggest, lone tree to get out of the rain.

There is not much we can do to protect ourselves from a direct hit. Conduction is something we can protect ourselves from, by not being in contact with any objects that can conduct electricity, including water.

By the way, even other people can conduct electricity, like when standing in a crowd.

Don’t Huddle-up

Lightning that strikes nearby will generate intense heat and electricity, possibly resulting in side-flash injuries.

Think of a lightning bolt like a hand grenade. The standard U.S. Army grenade has a kill radius of around 25 feet and a casualty (injury) radius of roughly 50-feet. A group of people, standing close together, will result in more casualties.

When lightning is present, don’t huddle together. Instead, spread out 25 to 50 feet apart. That way, if someone does go down after the explosion, others in the group can give aid.

Feet Together

While ground current kills or injures the most people every year, it is perhaps the easiest to protect ourselves from. If you find yourself outside with no good place to hide when lightning is striking nearby, then just stand still with both feet together.

The current that travels through the ground will take the path of least resistance and can go up one leg, through your body and exit out the other leg. Keeping your feet together at all times can prevent that current from getting to your vital organs.

3 Lightning Positions: Stand with feet together. Squat with feet together or sit Indian-style. To protect from ground-current only!

Final Review

If you can’t, “Get indoors when thunder roars”, as the National Weather Service slogan says, then:

1) Get to the best un-exposed location you can.
2) Get away from any metal objects you are carrying.
3) Spread your group at least 25 feet apart.
4) Stand with both feet together, and wait it out.

My hope is, by following this advice, you will have a safe and un-shocking summer.

 

This post appeared originally in the Jackson Hole News & Guide

Snow on the Summer Solstice

Is this going to be the endless winter? Today is officially the last day of Spring.
Friday at 9:54 AM MDT the Summer Solstice occurs and in the Rocky Mountains of Montana, Wyoming & northern Colorado, Summer 2019 is going to begin with some fresh snow!

Click Image below to see the forecast snow accumulation across the Northwestern U.S. from Thursday morning June 20th through Sunday morning June 23rd.

Click for snow accumulation forecast video. From CAIC.

It looks like the mountains of Southwestern Montana get the most accumulation, 7 to 11 inches possible at the higher elevations. Yellowstone Park, the Wind River Range and north-central Colorado’s mountains might see 3 to 6 inches of new snow to begin the summer season.

Cold Low-Pressure for June

This is all due to a very cold Low-pressure center in British Columbia that is swinging across the NW U.S. the next few days. Below is the general forecast map for the United States on Friday, June 21st, 2019. The first day of summer.

Click Map for the latest 3-Day forecast maps.

Also read the previous blog about: Very Cold Summer Solstice

Post by meteorologist Jim Woodmencey

 

 

 

Very Cold Summer Solstice

A very cold Low-pressure system will be rolling across the Pacific Northwest & Northern Rockies this week, just in time for the first day of summer.  The Summer Solstice is this Friday, June 21st and afternoon high temperatures will be running about 15 to 20 degrees below normal. And, yes, we may even see a little snow!

Click on the map below to watch the progression of the cold air as it sweeps across the Northwest U.S. This map is at the 700mb level in the atmosphere, or around the 10,000-ft. elevation. (Blue-green boundary is the freezing mark). Temps in the Tetons at 10,000-ft., for instance will  get down into the lower 20’s Fahrenheit.

COLD AIR COMING….

Click to see Video of 700mb (10,000-ft) Temp Forecast.  Maps from Windy.com

Get the updated temperature forecast for the next 5-days, for the Jackson Hole valley and the Teton mountains on the Jackson Hole Forecast.

Snow on The Summer Solstice?

While it will certainly be cold on Friday for the Solstice, it does not look like much precipitation  for the Jackson Hole area. The Tetons may get a little bit of fresh snow, and there will be the possibility of a few flakes to the valley floor.

How unusual would that be to have snow around the Summer Solstice? Pretty unusual.  Although, on June 18th, 1973 the Town of Jackson received 4 inches of snow from a cold, late June, storm system.

Also expect some strong winds Wednesday & Thursday, out ahead of the arrival of that cold air. Good news is, we start warming back up later Saturday and on Sunday.

Post by meteorologist Jim Woodmencey

Snow in June

Update Saturday morning, June 8th: (scroll down to read post from Friday)
Forecast verifying pretty well, seeing snowflakes in the Town of Jackson this morning. Snow on the ground down to around the 6,500-ft. elevation.

Grand Targhee is showing over 10 inches of new snow overnight and early this Saturday morning. Screen shots from webcams below….

Base of Grand Targhee Resort
From Spring Creek Ranch looking Northwest at Tetons
From the Climbers Ranch, Grand Teton National Park

How unusual is snow in June? Not too unusual, but accumulating snow in Town (elevation 6,200-ft.) in June is rare. The record one day snowfall in June in Jackson was 4 inches on June 18th, 1973.

Post From Friday, June 7th:
A cold Low-pressure system will be moving across the Pacific Northwest & Northern Rockies Friday & Saturday, June 7th & 8th. This will bring some rain, a few thunderstorms, and a mix of rain and snow to the mountains of Northwest Wyoming. A cold front is currently stalled over central Idaho, but it will progress eastward the next 24-hours.

Click Image for latest loop

Snow in June

Yellowstone National Park will see more significant accumulations of snow late Friday night/early Saturday morning. As well as, the Beartooth Mountains of Southwest Montana. Lesser amounts in the Tetons, Wind Rivers, & Bighorns of Wyoming. Snow levels will be low enough to possibly create a mix of rain and snow in Jackson Hole.

Better Weather Sunday

Good news is, all this weather moves east of the Rockies later Saturday, with drier weather & warming temperatures Sunday into Monday. Click the Forecast Weather Map below to see where the worst weather will be the next few days, across the USA.

Forecast for Friday June 7th, 2019. Click Map for latest 3-Day update.

 

Post by meteorologist Jim Woodmencey

Weather Pattern Changing

Weather is changing across the Western U.S. for the weekend…..Warm air in place ahead of a cold Low-pressure center positioned off the Pacific Northwest coast this morning. Isolated areas of early morning Thunderstorms started popping up at sunrise. An indication that the atmosphere is already quite unstable.

Satellite & Radar Images, plus lightning strike map from @ 0700 MDT Thursday, June 6th, 2019 below. (Today is the 75th Anniversary of D-Day, by the way).

Click Image for latest Sat loop
Click Image for latest Radar loop

 

Click Image for latest Lightning Strike Map

Below is Thursday’s Forecast Weather Map across the USA. Click the map to view the general weather outlook for next 3-days…..

 

Further updates on this weekend’s weather situation coming on Friday morning….

 

Post by meteorologist Jim Woodmencey