Here an article I’d like you to read. The money quote:

A personal note: I’ve met Nick and he is a dedicated public servant who wants to do the right thing. But, in this case, was sounding the sirens the right thing?

Here is the radar with the National Weather Service’s tornado warning plotted in red. You’ll notice only a small part (southwest) of Johnson Co. was in the tornado warning.

Sounding the sirens in Edgerton, Gardner, and Spring Hill was appropriate. I’d also say to sound them in Olathe because they are right on the edge of the warning. But the rest of the county?  No. It was a false alarm — the tornado dissipated before it reached Johnson Co.

Earlier in the evening, the sirens went off in Lawrence even thought it was never in a tornado warning (see below):

I’m sure that emergency manager thought he or she was doing the right thing and erring on the side of safety, as well.

Here’s the problem: We are training people to ignore the sirens because of all of these false activations.


The National Weather Service builds a “margin of safety” into the (relatively new, since 2005) “path-based” warnings. The emergency manager (who is not a meteorologist) building an additional margin of safety over and above the NWS’s leads to far too many siren activations.

When the sirens were pressed into tornado warning service in the 1950′s and 60′s, the “countywide” and “err on the side of safety” philosophy made sense because meteorology was not very good at tornado warnings.

Now, meteorologists can actually predict the path of tornadoes. I believe it is time for selective siren activation to become the norm.

I’m signing off for the night. Here are some thoughts that might be useful…

The full extent of the damage and injuries with the Iowa tornadoes is unknown at this time and likely till not be known until mid- to late Sunday morning.  There is a map of the tornadoes’ path in the posting below.

Here is the map of the greatest risk area I posted at 9:16am that encompassed northwest Iowa.

The tornado watch was out well in advance of the storms (scroll down). We define “significant” tornadoes as those of F-2 intensity or greater. There is a tool that helps us forecast where strong tornadoes may occur and it signaled that northwest Iowa was at risk (we look for values of more than 1, these were 6+). Storm chasers used this information to get into position to report on the storms and, when damage occurred, to help find and rescue the injured.

Why am I writing this? Because if you go to the WattsUpWithThat blog and read Why Are Weather Forecasts So Bad? and the comments from earlier today, you’ll learn that many people have the mistaken impression that meteorologists ‘never get it right.’ While that is often true with monthly and seasonal forecasting, our short term forecasts and storm warnings are usually excellent these days. Warnings need to be taken seriously. And, that is important as tomorrow could be another day of widespread severe weather (see graphic below):

The hatched area is where major tornadoes may occur. Please take the forecasts and warnings seriously as they are issued tomorrow and throughout this storm season.