National Weather Service Weather Forecast Office

 

August temperatures were slightly above normal, averaging 0.5 to 1 degree above normal. Spearfish was the warm spot averaging 4.5 degrees above normal. The cold

spot was Pactola Dam where temperatures averaged 0.7 degrees below normal.

Precipitation in August was near normal. The wettest areas were across southwest South Dakota, the Black Hills and northwest South Dakota where precipitation averaged 150 to 200 percent of normal. On the plains of central and south central South Dakota, rainfall was 40 to 60 percent of normal. The driest areas were across the northeast Wyoming plains where rainfall averaged 25 to 50 percent of normal. The wet spot was at Hermosa 3SSW where precipitation was 222 percent of normal, while Colony in northeast Wyoming was the dry spot with only 13 percent of normal precipitation. The rainfall deficit for the month averaged 0.05 inches.

 

 

On August 3, severe thunderstorms produced 60 mph winds across Harding, Perkins and Ziebach counties during the early morning hours.  In the late afternoon and evening hours severe thunderstorms produced hail to the size of quarters in southern Butte, northern Lawrence and central Custer counties.

 

On August 4, a strong upper level disturbance produced numerous severe thunderstorms and widespread reports of large hail and damaging winds across northwest and west central South Dakota during the early morning hours. The largest hail fell 15 miles northwest of Philip in Haakon County where ping pong ball size hail was reported. There were numerous reports of wind gusts of 60 to 70 mph.

 

On August 5, an isolated severe thunderstorm produced penny size hail near Porcupine in Shannon County in the early morning hours. In the late afternoon and evening hours a strong upper level disturbance produced widespread severe weather across northeast Wyoming, the northern Black Hills and west central South Dakota. In northeast Wyoming the largest hail reported was golf ball size and fell near Rockypoint and Devils Tower. The strongest winds reported were 70 mph near Rockypoint and Aladdin. In western South Dakota the largest hail reported was golf ball size and fell just west of Spearfish in Lawrence County. The strongest winds reported were 70 mph in Box Elder in Meade County.

 

On August 6, an isolated severe thunderstorm produced 70 mph winds and penny size hail near Sundance in Crook County in the early morning hours.

 

On August 9, an isolated severe thunderstorm produced penny size hail near Central City in Lawrence County in the early evening.

 

On August 10, an upper level disturbance produced severe thunderstorms across portions of northeast Wyoming and far western South Dakota. In northeast Wyoming the largest hail reported was the size of golf balls near Alva in Crook County. Wind gusts to 60 mph were reported near Aladdin in Crook County. In western South Dakota the largest hail reported was the size of quarters at Wind Cave in Custer County. The thunderstorms also produced flooding of small streams and creeks in northeast Butte County, southeast Harding County and across portions of central Custer and Fall River counties.

 

On August 11, a cold front interacted with a surface trough over western South Dakota to produce scattered severe thunderstorms across the central and southern Black Hills and in central South Dakota. The largest hail reported was golf ball size in Oglala in Shannon County and ping pong ball size in Millboro in Tripp County. Wind gusts to 60 mph were reported in Ideal in Tripp County.

 

On August 12, an upper level disturbance brought scattered severe thunderstorms to the central Black Hills and southwest South Dakota. The largest hail reported was the size

of golf balls in Rapid City. Wind gusts to 70 mph were reported in far northwest Shannon County.

 

On August 13, an upper level disturbance brought scattered severe thunderstorms to the southern Black Hills, southwest South Dakota and south central South Dakota. The largest hail reported was the size of ping pong balls near Colome in Tripp County. Wind gusts to 60 mph were reported northwest of Edgemont in Fall River County.

 

On August 14, an isolated severe thunderstorm produced hail to the size of quarters near Millboro in Tripp County.

 

On August 24, an isolated severe thunderstorm produced hail to the size of golf balls 19 miles southeast of Wright in Campbell County. Another isolated severe thunderstorm produced hail to the size of quarters across southern Lawrence County.

 

On August 26, an isolated severe thunderstorm produced hail to the size of pennies and 60 mph wind gusts at Manderson in Shannon County.