National Weather Service United States Department of Commerce

Cold Front Moving Through the Northeast U.S. Monday; Atmospheric River to Impact the Pacific Northwest Midweek

A cold front will cross the Great Lakes and Northeast U.S. through Monday with gusty winds and areas of rain showers. A strong atmospheric river is expected to move into the Pacific Northwest by midweek bringing a threat for moderate to heavy rainfall, gusty winds, and mountain snows for parts of Washington, Oregon, northern California, and the Sierra Nevada. Read More >

Event Summary

A potent upper level system and associated surface cold front brought strong to severe thunderstorms across the Tennessee Valley during the late evening and early mornings hours of Monday night and Tuesday. Monday morning started on rather cool and cloudy note, with temperatures only rising into the lower 60s by the afternoon. However, a powerful low level jet kept a steady stream of moisture and warmer air filtering into the region. This led to a northward progression of a warm front, that passed through the area during the evening hours, placing the Tennessee Valley within the warm sector of this system before midnight. With the placement of this warm front, rapid destabilization occurred, as the cold front continued moving eastward Monday night. Meanwhile, the low level jet produced wind speeds between 60 and 70 kts, leading to low level wind shear peaking around 40 kts to combine with instability up to 1500 j/kg.

As all of this was occurring, showers and thunderstorms began to develop across the ArkLaTex Monday afternoon ahead of the cold front, spawning several tornadoes in northern Louisiana. These storms merged into a broken line of storms and quickly moved eastward Monday night. As the pushed east of Mississippi River, several more tornadoes touched down and caused damage across northern Mississippi. These storms continued into northwest Alabama around 11 pm, moving into an environment that was well primed for these storms to maintain their strength and organization, leading to a few tornadoes to touch down and move across northern Alabama and southern middle Tennessee, as well as several in middle Tennessee, serviced by the Nashville NWS office. One of the strongest tornadic circulations occurred in northeastern Franklin county in Tennessee and produced at least EF2 tornado damage. Below are radar images of this storm as it was moving east-northeast east of the Estill Springs community.

Image Image

 

Storm Surveys are still being completed by National Weather Service employees. However, at least one more tornado in Franklin  and Colbert counties in Alabama, occurred.  


Image Storm Reports
Tornado Watch # 420 - Valid 525 AM through 1 PM CDT SPC Storm Reports for 11/05/18