22 April 2005

Stormy Weather and Screaming Sirens

Looks like we will see a significant severe weather event on Friday. Even the risk of some tornadoes is a bit higher than I thought earlier in the day. Then come a real cold snap!

Right now it still looks to me as if mid 30's are likely Sunday morning. On Monday with calm winds the cold pockets in Dekalb and Jackson counties may very well see some frost. In case your wondering, the latest freeze on record for Huntsville is May 2, 1909.

The severe storms have got me to thinking about an issue that is getting more attention lately. The criteria for Severe Thunderstorm Warnings.

Presently a severe thunderstorm is defined as winds greater than 55kts (58mph) and hail greater than 3/4inch in diameter.

However, research has shown that damage from hail does not really start until the hail size reaches 1 inch and even then it is not common.

This issue was discussed at a weather conference I attended a couple of years back. If the criteria were raised to say 1 inch hail and winds greater than 60 mph, there would be fewer warnings and the ones that were issued would have more impact.

I come down on the side of changing the criteria. I do not like to break into programming for a severe thunderstorm warning with penny size hail. It rarely causes damage.

Changing the criteria would mean fewer weather alert maps on the screen as well...that is a real plus!
(An NWS office in the Midwest is presently issuing severe warnings on the higher criteria on an experimental basis.)

It will require a real effort to educate the public though. I very frequently get calls from viewers who want to know why I haven't broken into programming when they are getting dime size hail and 50 mph winds. When I explain that the storm they are experiencing is not severe, I'm usually met with great skepticism.

No warnings are presently issued for lightning, but it kills more than tornadoes in most years!. I now will crawl a warning to viewers if I see a storm with a very high flash rate moving into a dense population area (That usually causes power outages)

One last thing while we are on the subject...
Tornado Sirens

They cost a bundle.
They're 1920's technology
-and think to yourself, how many times was your first warning of severe weather from a siren?? Very few I suspect.

Usually people hear the tornado warning on TV or radio and run out into the yard to listen to the sirens!
Something is wrong here.

I did the math one time and figured out that for the cost of a new tornado siren, you could buy everyone within the sound of it a NOAA weather radio with money left over!

Yes, there are a few cases where they may do some good...but the question is-
Can you justify the expense when more technologically advanced methods of warning are now available??

That and every community has a different standard for setting them off. I no longer make "siren announcements" during severe weather coverage..I have more important information to pass on.

18 April 2005

Neat Sky Show This Week

Working as a Meteorologist in TV has it's rewards but it can be a bit lonely. The 3 of us in the weather office have to cover the entire day..all year. So we actually do not see much of each other!

When there is something neat going on..there are usually no other Meteorolgists to talk too about it! Sometimes I will open the chat client we have with the NWS and talk to some of Mets. over there or call a friend in another part of the country.

One interesting thing though is breaking news..I usually know the big story before you do! (But not for long if the news folks are on top of their game and they usually are.)
Today they came back and ask if I could use the high resolution mapping in ARMOR to look at the intersection in Meridianville where a shooting occured. I quickly zoomed in on the intersection but had no idea which building was the pawn shop they were looking for.

Here is where having a guy who has been covering news here for 30 years is a big plus. I grabbed our assignments manager Keith Lowhorne..he started with the station in the early 70's. He looked at the screen for a second and then pointed at the building. I put some text by it to identify and called the graphics department so they could grab the image for a breaking news graphic.

Great sky show this week as Jupiter passes very close to the moon Wednesday-Friday. With clouds on Thursday and Friday, it may be best to look Wednesday. High in the SSE sky about 9-11pm you should see an almost full moon and a very bright Jupiter close together. If the sky is fair on Thursday they will be even closer.

Jupiter is very close to earth right now. Around 400+ million miles. (well close in an astronomical sense.) It will be quite bright and should look interesting in high powered binoculars.
A great web site for keeping track of what to see in the sky is here:
www.skyandtelescope.com

Later!
Dan