May 6, 1999 High Wind Event

May 6th, 1999 12Z Surface Analysis

On May 6th, 1999 the wind blew real hard across western South Dakota and portions of northeast Wyoming. The cause was the big "L" you see on the 12Z surface analysis above.  Each isobar represents a 4mb pressure difference. Notice, there are 5 isobars over western South Dakota. There was a large 15mb pressure difference between the low and Rapid City. Pretty impressive. The result was very strong winds across the area. Below you will find a textual summary of the speeds along with a contour map. This is just a partial list.

BLACK HILLS POWER/WEST RAPID CITY    87 MPH
ELLSWORTH AIRFORCE BASE 85 MPH
RAPID CITY NWS 83 MPH
TILFORD WEIGH STATION 74 MPH
BADLANDS NATIONAL PARK 72 MPH
WALL 69 MPH
RAPID CITY AIRPORT 68 MPH
BUFFALO 67 MPH
NEWELL 63 MPH
MILESVILLE 9N 61 MPH
PHILIP 59 MPH
FAITH 59 MPH
STURGIS 55 MPH
WINNER 52 MPH
LEMMON 52 MPH
PINE RIDGE 48 MPH
ST. FRANCIS 47 MPH

Peak Wind Map

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