Bill Murray wrote a great here on the blog yesterday about raising the bar for severe thunderstorm warning criteria. I have been an advocate of this for a number of years since I really have a hard time finding anyone who really pays attention to severe thunderstorm warnings.
I have discussed this often on our old "Weather Talk" articles before the blog format started.
Our friend Jason Kelly down in Panama City tipped us off concerning a trial NWS program in three of their offices this year. The severe hail criteria will be raised from 3/4” in diameter to 1” in diameter in Wichita, Springfield, MO, and Pleasant Hill, MO. I am optimistic that this trial will work out nicely, and I expect the NWS at some point down the road to raise the severe hail criteria to 1” nationwide. This should cut back on the number of marginal severe thunderstorm warnings.
I expect the severe thunderstorm wind criteria to remain at 58 mph due to demand from EMA officials and the public. And, I am pretty much in agreement that this criteria needs to remain unchanged. We just need to be certain that winds really are 58 mph or higher if a warning is issued based on wind.
I also would like to see one additional message created called a “severe thunderstorm emergency”. This would be used in a rare situation like a major Derecho when winds can be very widespread, and possibly exceeding 100 mph. A good example of this was when a severe storm hit Memphis during the early morning hours on July 22, 2003...winds of up to 100 mph shredded the city. Roofs of some building came off. Half the city was without power. Damages topped $6 million; cleanup costs were over $40 million. Most folks that day simply ignored the “standard” severe thunderstorm warning as usual... which was issued well before the damage started. I would suggest a "severe thunderstorm emergency" would have captured more attention.
I also believe the "tornado emergency", which is now being used informally by the NWS should be a formal part of the warning package as well. Reserved when a significant tornado is being watched by spotters and is causing significant damage. A good example of this would be the Tuscaloosa tornado of December 16, 2000, when the world was watching that big F4 on our live towercam.
Thanks to everyone who posted comments on Bill's original post... very interesting....
I have discussed this often on our old "Weather Talk" articles before the blog format started.
Our friend Jason Kelly down in Panama City tipped us off concerning a trial NWS program in three of their offices this year. The severe hail criteria will be raised from 3/4” in diameter to 1” in diameter in Wichita, Springfield, MO, and Pleasant Hill, MO. I am optimistic that this trial will work out nicely, and I expect the NWS at some point down the road to raise the severe hail criteria to 1” nationwide. This should cut back on the number of marginal severe thunderstorm warnings.
I expect the severe thunderstorm wind criteria to remain at 58 mph due to demand from EMA officials and the public. And, I am pretty much in agreement that this criteria needs to remain unchanged. We just need to be certain that winds really are 58 mph or higher if a warning is issued based on wind.
I also would like to see one additional message created called a “severe thunderstorm emergency”. This would be used in a rare situation like a major Derecho when winds can be very widespread, and possibly exceeding 100 mph. A good example of this was when a severe storm hit Memphis during the early morning hours on July 22, 2003...winds of up to 100 mph shredded the city. Roofs of some building came off. Half the city was without power. Damages topped $6 million; cleanup costs were over $40 million. Most folks that day simply ignored the “standard” severe thunderstorm warning as usual... which was issued well before the damage started. I would suggest a "severe thunderstorm emergency" would have captured more attention.
I also believe the "tornado emergency", which is now being used informally by the NWS should be a formal part of the warning package as well. Reserved when a significant tornado is being watched by spotters and is causing significant damage. A good example of this would be the Tuscaloosa tornado of December 16, 2000, when the world was watching that big F4 on our live towercam.
Thanks to everyone who posted comments on Bill's original post... very interesting....
on March 1, 2005, 5:42 pm
Being a weather enthusiast, I knew of the storms before they reached Memphis, unlike most everyone else. Most were either asleep as it was summer and there was no school, or were busy getting ready for work and unconcerned with the warnings being repeatedly relayed on TV.
When warnings (severe or tornado) are issued for the metro area, all of the TV stations go into extended "wall to wall" coverage. They did that morning as well. But, because it was not a tornado, most continued to ignore it. It was not until the storm hit and the power went out before people understood the significance.
Although their were radar issues that morning and the storm didn't reach its full strength until crossing the MS River, if the NWS had used an "emergency" wording as you suggest those ahead of the path further east could know the danger of what was coming.
Here in Memphis Tornado Emergencies were just started, and they performed well last October 18th when a tornado hit Dyersburg, TN. There was a lot of damage but no injuries. The media constantly relayed the "emergency" wording and this helped people in Dyersburg know how dangerous the storm was.
Also, I believe that changing the hail criteria to 1" would be more beneficial, and smaller hail could be handled in significant weather advisories that are already issued here. The 58 mph wind criteria should stay the same.
Thanks for listening to my comments, and I love reading this blog daily, even though I don't live in Alabama!
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