EF1 tornado in Barnstable County, Massachusetts

A waterspout moved onshore just west of Kalmus Beach in Barnstable, MA at 1157 AM EDT (1057 AM EST). Winds gusted to 91 mph at a mesonet observation site at Kalmus. They had shifted from southeast to west-northwest with the passage of the tornado. The tornado continued moving northeastward at about 35 mph. The damage was discontinuous but where the tornado touched down, the damage was quite significant, with winds estimated as high as 110 mph.

The roof of a motel on the south side of Main Street in West Yarmouth was completely peeled off. Additional significant tornado damage occurred just southwest of the Dennis-Yarmouth Regional High School, particularly along Hazelmoor Road from Violet Glen Road to Vine Brook Road. Dozens of large trees were uprooted and a few were snapped off. Another house had a hole in the roof from a fallen tree.

The tornado then lifted. However, severe straight-line wind damage was observed from West Dennis eastward to West Harwich. Numerous large trees were uprooted, consistent with 90 mph gusts or greater.

Amazingly, no injuries were reported with the storm. Cleanup of roads cost approximately $434,000 in Yarmouth. That does not count damage to homes or private claims.

A deep southerly flow of tropical moisture was in place over southeast MA with precipitable water values in excess of 2 inches on the south coast. A frontal wave along the coast provided strong low level convergence and that combined with upper divergence from the right entrance region of a 110 knot upper level jet to produce very severe weather for Cape Cod. Three tornadoes occurred! Prior to these, there had only been three recorded tornadoes since 1950. Outside of the tornado area, damage surveys showed that strong microburst winds caused straight-line damage.