The low precipitation supercells are much more common in the plains and areas west of the Mississippi
ATLANTA – Two tornadoes have now been confirmed by New Year’s Eve in northern Georgia – one EF-1 in Covington and another EF-1 in northern Carroll Counties around Temple and Villa Rica.
While it is not uncommon for us to see thunderstorms in Georgia in December, the thunderstorms that caused these tornadoes are very rare in Peach State.
New Year’s thunderstorms are classified as mini ‘Low precipitation’ supercells.
Supercell thunderstorms are not uncommon in Georgia. We often see them before gusts of wind during classic storm events in spring. However, supercell thunderstorms can be divided into three sub-categories: classic, with high precipitation and with low precipitation. In Georgia, the first two are our most common species.
Low precipitation supercells are common in the Great Plains but are very rare east of the Mississippi. In fact, the last time this type of storm occurred in our area was more than 15 years ago on January 2, 2006, according to the National Weather Service in Peachtree City, Georgia.
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As the name suggests, Low Precipitation Supercells, LP supercells for short, are characterized by less rain. On the radar, the rain surface is often much smaller and separate from the rotating part of the storm, the mesocyclone. The lowering wall cloud and the funnel / tornado are more visible to storm chasers because the precipitation is very low. The tornadoes are not shrouded in heavy rain like in our normal Classic or HP Supercell events.
Low precipitation supercells can also pose a threat to very large hailstones. We already had that during the 2006 event, but that didn’t affect our New Year’s Eve storms.
Friday’s storms can also be classified as “mini” or “low-top supercells” due to their minor nature. Some of these storms were only 6-8 miles in diameter!
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