Recent NWS Tornado Surveys and Photos

When a storm hits, the government's National Weather Service springs into action to do "storm surveys" of damaged areas. This allows them to determine whether damage was done by a tornado or straight-line winds.* This involves taking using photos taken aerially or on the ground, along with maps & compasses to determine the direction in which trees have fallen or debris was blown. Now, the NWS is using more modern tools such as GPS, high-resolution digital photography, and Google Earth to help in this process.

Now, I said earlier this week that severe weather season has been slow so far, but that doesn't mean that some damaging storms haven't rolled through - most notably in the Carolinas on March 28 and in the Midwest April 5-7. A recent excellent example of using these newer technologies with storm surveys is this one from two EF-2 tornadoes March 28, 2010 tornadoes under the coverage of the Columbia, South Carolina office.

By opening their KMZ file in Google Earth, you can essentially "fly" along the track of the tornado which goes up and down the terrain as a yellow line, while you can pick out actual houses from the Google satellite imagery while comparing them with damage photos. The pictures from this event were impressive and lend credence to the sayings that tornadoes can severely damage things while leaving others nearby nearly untouched. I find it fascinating to be able to see the tornado track from the air, to think what that storm was actually doing as it plowed over the landscape.

More amazing damage photos can be viewed from the NWS in Raleigh NC where an EF-3 and EF-2 tornado struck, the same day as the storms moved into the Piedmont. Their office isn't using Google Earth but includes maps with photos in PDFs for Davidson and Guilford Counties. You can view all of the photos from both events on our Photo Gallery at the link below.

The NWS in Des Moines has also issued a PDF with maps and photos included from a straight-line wind damage event that blew in garage doors, bent over street signs, and stripped houses of their siding with winds estimated to 105 mph on April 6th. Some of the photos are from Grinnell, Iowa, where four runners were also severely injured by hail (see photos of their bruises). And last but not least, the NWS in Davenport, Iowa has issued a report with radar images and photos of a high wind event, estimated near 100 mph, on April 5th. Photos from those events are showcased below.

*Of course, to those who have lost property or lives, it doesn't matter; either can cause massive destruction, but to meteorologists this determination is important for weather research and statistics. On a side note, you used to be able to fly tornado paths of historical tornadoes with Google Earth's "fly" tool via a University of Michigan web page, but this seems to have disappeared.