Severe Weather Outbreak-February 13, 2007

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Summary

An upper-level trough of low pressure pushed toward the Southeast U.S./Gulf Coast region while an associated surface low pressure system developed across eastern Georgia and western South Carolina and tracked east across central/southern South Carolina. Ongoing convection intensified along and south of the surface low pressure track during the mid to late afternoon. Strong low to mid-level winds along with decent low-level instability within the developing warm sector supported a line of thunderstorms with embedded bow features and strong rotation within a bookend feature at the northern end of the line closest to the surface low pressure. See image below for a surface analysis/radar composite from the Hydrometeorological Prediction Center valid at 7 PM EST.

See below for a summary of the damage survey conducted by the National Weather Service.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC 
920 AM EST FRI FEB 16 2007

...ADDITIONAL INFORMATION ON TWO TORNADOES AND DOWNBURST DAMAGE THAT 
OCCURRED ON FEBRUARY 13TH IN SCREVEN COUNTY GEORGIA AND ALLENDALE 
COUNTY SOUTH CAROLINA...

A TORNADO DEVELOPED 2 MILES EAST OF SYLVANIA IN SCREVEN COUNTY 
AROUND 628 PM AND TRAVELED NORTH-NORTHEAST ABOUT 6/10TH OF A MILE 
BEFORE LIFTING AROUND 629 PM. MAXIMUM WIDTH OF THIS TORNADO WAS 35 
YARDS. USING THE ENHANCED FUJITA SCALE...THIS TORNADO WAS RATED F1 
WITH HIGHEST WIND SPEEDS ESTIMATED AROUND 105 MPH. THIS TORNADO 
DESTROYED A PUMP HOUSE...KNOCKED A LARGE TREE BRANCH INTO A 
CAR...DAMAGED A MOBILE HOME AND AN OUTBUILDING AND UPROOTED AND 
SNAPPED OFF NUMEROUS TREES...MOST OF WHICH WERE DECIDUOUS TREES WITH 
NO LEAVES. BEFORE LIFTING THE TORNADO NARROWED AND REACHED ITS 
MAXIMUM INTENSITY IN A PECAN ORCHARD. HERE NEARLY A DOZEN LARGE 
PECAN TREES WITH NO LEAVES ON THEM WERE UPROOTED. SEVERAL OTHER 
PECAN TREES HAD LARGE LIMBS BROKEN OFF.

ABOUT A MILE AND A HALF NORTH-NORTHEAST OF THE TORNADO MENTIONED 
ABOVE AND ABOUT 3 MILES NORTHEAST OF SYLVANIA...A LARGE AND POWERFUL 
DOWNBURST PRODUCED AN ESTIMATED 400 YARD WIDE BY 800 YARD LONG 
SWATH OF DAMAGE AROUND 632 PM. OVER 100 TREES WERE UPROOTED OR 
SNAPPED OFF. NUMEROUS VERY LARGE DECIDUOUS TREES WITH NO LEAVES WERE 
UPROOTED IN THIS AREA...THE SKIRTING OF SEVERAL MOBILE HOMES WERE 
TORN OFF...A MOBILE HOME WAS PUSHED 2 FEET OFF OF ITS 
FOUNDATION...SHINGLES WERE TORN OFF OF HOMES...A POP-UP CAMPING 
TRAILER WAS FLIPPED OVER...A FENCE WAS DAMAGED...THE FRONT OF A 
LARGE CAMPING TRAILER WAS MOVED A FOOT OR TWO AND A SATELLITE 
ANTENNA WAS KNOCKED DOWN. MAXIMUM WIND SPEEDS IN THIS AREA WERE 
ESTIMATED TO BE UP TO 105 MPH.

THE SAME STORM PRODUCED A SECOND TORNADO ABOUT A MILE SOUTHEAST OF 
ALLENDALE IN ALLENDALE COUNTY SOUTH CAROLINA AROUND 701 PM. THIS 
TORNADO WAS ONLY BRIEFLY ON THE GROUND AND TRAVELED NORTH-NORTHEAST 
ABOUT 60 YARDS BEFORE LIFTING. THE TORNADO WAS ABOUT 30 YARDS WIDE. 
THIS TORNADO UPROOTED OR SNAPPED OFF NUMEROUS TREES AND DAMAGED THE 
THE SKIRTING OF A MOBILE HOME. USING THE ENHANCED FUJITA SCALE...THE 
TORNADO HAD MAXIMUM WIND SPEEDS ESTIMATED TO BE AROUND 90 MPH. THIS 
PUTS IT IN THE LOW END OF THE F1 CATEGORY.

Tornado/Downburst Maps

Damage Pictures

Sylvania, Georgia (courtesy of NWS Charleston)