Ratings of Tornadoes

This past Sunday evening, just before 9p.m., a tornado quickly formed on the west side of Sanford Lake in Midland County. Home video sent to me by Alice Kole of Sanford just after it occurred confirmed a tornado formed. While Alice was not a Trained Spotter or Storm Chaser, she was at the right place at the right time and braved the storm to capture it. Just by looking at the video, you really cannot tell the true strength of it. Granted, there was not much debris associated with it on the video. Afterwards, the National Weather Service from Detroit surveyed the area and located some damage to boat hoists, a boat and piers. Also, some trees were snapped in half. The NWS indicated the tornado was 50 yards wide, tracked from just north of the mouth of Verity Creek on the western side of Sanford Lake, across the lake (as a waterspout), and went on land again on the east side of the lake to the south end of North Weeping Willow Lane. Total distance on the ground and water was about .4 miles. Maximum wind speeds, after looking how the bad the damage was, were about 65mph. This gives it a rating as EF0 (EF-zero). So, really, this tornado was not even at hurricane force. The EF scale came in use February 1, 2007. EF stands for Enhanced Fujita . The original Fujita scale was developed by Dr. Tetsuya Fujita in 1971. But the EF scale is now used as it was developed by a forum of meteorologists and wind engineers. It is used to assign a tornado an improved “rating” based on estimated wind speeds and related damage. The ratings for from EF0 to EF5. This EF scale replaced the old F scale to reflect better examinations of tornado damage surveys so as to align wind speeds more closely with associated wind damage. This new EF scale had to do with how most structures are designed. Here is how the ratings are ranked according to wind speeds: EF0———-65-85mph EF1———86-110mph EF2——–111-135mph EF3——–136-165mph EF4——–166-200mph EF5——-Over 200mph The original Fujita scale was this: F0————-<73mph F1----------73-112mph F2---------113-157mph F3---------158-206mph F4---------207-260mph F5---------261-318mph The strongest tornado recorded (having the highest wind speed) was in Moore OK, May 3, 1999 where meteorologists utilizing Doppler on Wheels measured a wind speed of 318mph. Doppler measured these winds a couple hundred feet above the ground. Moore was in the middle of this long path of 38 miles being on the ground. The tornado was a mile wide at times. That was a high-end F5 tornado using the old scale, but a extreme high EF5 on today's scale. The devastating tornado that struck Joplin MO, this past May 23, had wind speeds topping 200mph, was 3/4 mile wide and lasted 6 miles. So, this tornado, while spectacular on video and watching it in person, could have been much worse. But it was exciting nonetheless for those who watched it and video taped it! Thanks again for Alice Kole for getting that video to me soon after it happened Sunday evening! -Meteorologist Jim Lehocky