I'm going to present some of the forecasts of the tornadoes in the Carolinas -- well outside of tornado alley -- to illustrate my point.
If you were reading this blog Friday afternoon (the first tornado in the Carolinas touched down at 2:08pm EDT Saturday) you saw this map generated from NWS storm probabilities. The hatched area indicated where significant (F2 or greater on the Fujita Scale) were likely to occur.
The NWS issued its routine public severe weather outlook at 2am EDT Saturday morning (12 hours and 8 minutes before the first tornado). Here is the forecast (the red line is the higher risk area) compared to the actual reports of severe weather (red triangle = tornado). One hundred percent of the tornadoes are in the outlook area and 98% are within the higher risk area more than 12 hours in advance!
The National Weather Service issued two more public updates between the forecast above and the first tornado. When it came time to issue the tornado watch, they issued a rare "particularly dangerous situation" (PDS) tornado watch for the Carolinas (there was a regular tornado watch farther north). There are years where not a single PDS tornado watch is issued. It was out 1 hr. and 3 minutes before the first tornado touched down.
I do not want to go into each of the warnings because that would be far too long of a posting. You can see for yourself by going back to yesterday's postings and scroll up (forward in time). I believe you'll be very impressed with the amount of advance warning.
So, why did people die?
Given the sheer number of tornadoes and the strength of the tornadoes combined with the population density of the affected areas, some deaths were inevitable. I'm told that most communities in North Carolina do not have tornado sirens, which might be a factor. It is too soon to know if everyone received the warnings in time (i.e., in the 2007 Greensburg, KS tornado, everyone but a trucker from California received the warning as far as can be determined). The NWS will likely make these determinations via their damage surveys.
Based on early news reports, at least half of the deaths in North Carolina were associated with mobile homes. A helicopter shot I saw clearly showed at least some nearby mobile homes were not tied down. It is my opinion, based on years of study and research, that an untied mobile home is completely unsafe in a tornado.
|Screen capture from WRAL TV helicopter video showing the mobile home pad (upper left) and|
the stripped mobile home chassis moved off the pad. The mobile home
may have tumbled as it moved.
We are getting to the point in America that the issue is not so much whether there will be an advance warning but making sure that everyone who needs to receive the warning gets it.