Weather Spotter Training Notes
Posted: Thu May 12, 2011 2:31 pm
I recently attended a Weather Spotter training session held on Thursday, 5 May 2011, at the DES office here in Great Falls.
Much of the training concerned tornadoes and what to look for when trying to confirm for the National Weather Service (NWS) if an actual tornado is on the ground. The doppler weather radar is a vast improvement over older systems, but the NWS still needs ground observers to help confirm what is actually happening. Radar images that are suspicious in nature don't always provide the detail necessary to confirm the existence of a tornado. What the NWS needs is "ground truth" from weather spotters confirming that:
1. The clouds are rotating
2. A funnel cloud has descended AND is in contact with the ground (swirling debris are visible at ground level).
Sometimes a funnel cloud will form and start to descend, but will fail to reach the ground. After a few minutes it simply dissipates. If it does not reach the ground, it is NOT a tornado!
Another item of discussion was lightning. Did you know that lightning can strike up to 10-miles AHEAD of the thunderstorm?! The NWS reports that most people killed by lightning strikes were struck well before the thunderstorm passed overhead, or well after the storm had passed. The threat of lightning is not just when the thunderstorm is directly overhead and the rain is pouring down! Lightning can strike up to 10-miles AHEAD or BEHIND the actual storm cell.
The NWS has a slogan, "When thunder roars, go indoors!"
Once you seek shelter inside, stay there until no thunder has been heard for 30-minutes. The 30-minute rule means you should not wait until the rain reaches your location before seeking shelter. Because lightning often strikes ahead of the storm cell, if you hear thunder in the distance - don't wait for the rain, go inside now! A good example would be a baseball game. Game officials should not wait until the rain actually reaches the field. If you can hear a thunderstorm in the area, stop the game and get everyone into shelter.
Places to AVOID during a thunderstorm would be baseball dugouts, gazebos, open porches, tents, or outdoor areas near water or tall structures such as trees. Move away from steel fences and support poles. Get inside a regular building and wait out the storm.
Getting zapped by lightning is no fun!
Much of the training concerned tornadoes and what to look for when trying to confirm for the National Weather Service (NWS) if an actual tornado is on the ground. The doppler weather radar is a vast improvement over older systems, but the NWS still needs ground observers to help confirm what is actually happening. Radar images that are suspicious in nature don't always provide the detail necessary to confirm the existence of a tornado. What the NWS needs is "ground truth" from weather spotters confirming that:
1. The clouds are rotating
2. A funnel cloud has descended AND is in contact with the ground (swirling debris are visible at ground level).
Sometimes a funnel cloud will form and start to descend, but will fail to reach the ground. After a few minutes it simply dissipates. If it does not reach the ground, it is NOT a tornado!
Another item of discussion was lightning. Did you know that lightning can strike up to 10-miles AHEAD of the thunderstorm?! The NWS reports that most people killed by lightning strikes were struck well before the thunderstorm passed overhead, or well after the storm had passed. The threat of lightning is not just when the thunderstorm is directly overhead and the rain is pouring down! Lightning can strike up to 10-miles AHEAD or BEHIND the actual storm cell.
The NWS has a slogan, "When thunder roars, go indoors!"
Once you seek shelter inside, stay there until no thunder has been heard for 30-minutes. The 30-minute rule means you should not wait until the rain reaches your location before seeking shelter. Because lightning often strikes ahead of the storm cell, if you hear thunder in the distance - don't wait for the rain, go inside now! A good example would be a baseball game. Game officials should not wait until the rain actually reaches the field. If you can hear a thunderstorm in the area, stop the game and get everyone into shelter.
Places to AVOID during a thunderstorm would be baseball dugouts, gazebos, open porches, tents, or outdoor areas near water or tall structures such as trees. Move away from steel fences and support poles. Get inside a regular building and wait out the storm.
Getting zapped by lightning is no fun!