Tornadic  Thunderstorm Types in the Northeastern United States

Bow Echoes

Tornadic Thunderstorm Types in the Northeastern United States

Introduction

Supercells

Appendages

Bow Echoes

Boundary Interaction

Miscellaneous Types

 Summary Table

References

We are all aware that bow echoes are an important producer of severe weather in the Northeast.  However, it was surprising to find that bow echoes were extremely important in the production of tornadoes.  About a third (34%) of the 86 tornadoes in this study were associated with bowing cells or bowing line segments. Two thirds (67 percent) of the bow echo tornadoes  formed on the apex of the bow. Typically, bow echo tornadoes were F0 or F1 intensity and harder to warn for because there often was no clearly defined velocity couplet.   Pryzbylinski (1995) documented areas of intense shear at the leading edge of derechos and bow echoes, and sometimes found them to be associated with transient tornadoes.

An unusually intense F2 tornado on 31 May 1998 was associated with a bow echo.  The line of storms moved east across Albany County, crossing the Hudson River into Rensselaer County.  A 200 yard wide F2 tornado touched down  2 miles northwest of East Schodack at 2332 Utc (7:32 pm local time) and was on the ground for 8 miles.