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Erin Strengthens to a Hurricane; Heavy Rainfall Possible in Puerto Rico and the Virgin Islands, the Upper Midwest, South Texas

Hurricane Erin may bring isolated flash and urban flooding, landslides or mudslides, and possible tropical storm conditions to Puerto Rico and the U.S. Virgin Islands this weekend. Scattered thunderstorms and heavy rainfall may bring areas of flooding this weekend over the Upper Midwest. A tropical disturbance will bring locally heavy rain and mainly urban flash flooding to far southern Texas. Read More >

On May 11th, 2003 a tornado developed in the fields near Warden, WA. The photographer reported "I was about 2.5 miles north of the twister, and it blew out a storage shed wall and moved a water tank on the farm that was under it. At the same time, I took a different picture of a funnel cloud (last picture below) that was up in the clouds, above me. In talking to someone who saw it from Othello, which is 15 miles to the east, I was told the twister later leaned over sideways, and the bottom lifted up, and it was horizontal, before receding back up into the clouds." This sequence of photos shows what could have been a "non-descending" tornado. A ciruculation (such as a dust devil) originates at the surface. Meanwhile air near the ground is being drawn into a cumulus cloud (in this case, it wasn't even a thunderstorm). This is known as an updraft. The updraft stretches the circulation, causing it to spin faster, much like an ice skater increases her speed of rotation by drawing her arms in. As the updraft continues, the circulation is drawn up into the sky. The last photo shows a funnel cloud that is clearly originating from the base of a cloud but not touching the ground. This funnel cloud was not associated with the tornado, but it does indicate that the storms that day did have the ability to produce funnels without having a surface circulation. The picture above the funnel cloud image shows that the tornado did not have any associated circulation in the clouds, which again indicates that it may have been a non-descending tornado.

Dust Devil Warden