Lala Approaching Hawaii; Flash Flooding Risks; Excessive Heat

Lala, may become a hurricane, is expected to impact Hawaii this weekend. Heavy rainfall, strong winds, dangerous surf and localized flooding are expected. Heavy rainfall and flash flooding concerns from the mid-Mississippi Valley, Ohio Valley into the central Appalachians continues, with the threat shifting toward the mid-Atlantic later this weekend. Record heat continues for areas of the South. Read More >

First EF4/F4 Tornado Reported in South Dakota Since 2003

On 22 May 2010, a strong supercell thunderstorm produced an EF4 tornado in Edmunds County near Bowdle, SD. This was the first EF4 tornado in South Dakota since the destructive F4 tornado on 24 June 2003 near Manchester, SD. Looking back at tornado records since 1950, there have only been seven other F4 or F5 tornadoes in South Dakota:

Location	Date	Rating
Tripp County	5/8/1965	F5
Yankton County	6/7/1965	F4
Turner County	6/7/1965	F4
Harding County	7/7/1969	F4
McCook County (Spencer)	5/30/1998	F4
Brown County (Barnard)	6/23/2002	F4
Kingsbury County (Manchester)	6/24/2003	F4
Edmunds County (Bowdle)	5/22/2010	EF4

Fact Sheet:

A couple other interesting tornado facts are listed below:

This is only the second EF4/F4 tornado in the Aberdeen County Warning Area (CWA) since 1950. The other F4 tornado occurred in Brown County on 23 June 2002 near the town of Barnard.

There have been no official EF5/F5 tornadoes in the Aberdeen CWA, and only one in South Dakota since 1950 (in Tripp County).

From January 1950 through February of 2010, the total number of tornado reports in South Dakota (EF0+) is 1592. Not including the Bowdle tornado, the percentage of EF4/F4 or EF5/F5 tornadoes is only 0.004 (or 0.4%). In other words, these destructive tornadoes are extremely rare across South Dakota!

Radar Loops:

The images below are from the NWS Doppler Radar in Aberdeen, SD (KABR). The image loop runs from 6PM CDT (2200 UTC) through 930PM CDT (0230 UTC). Figure 1 is the 0.5° base reflectivity data, and Figure 2 below shows 0.5° base velocity data. Click on the images for a higher resolution image loop.

Figure 1:

Figure 2:

ABR RSS Feed

Lala Approaching Hawaii; Flash Flooding Risks; Excessive Heat

First EF4 (F4) Tornado in South Dakota Since 2003