Hail

> 1.00”

AND/OR

Wind

> 58 mph (50kts)

AND/OR

Significant Wind Damage, i.e., Trees down, large tree limbs down, structural damage to buildings.

Tornado

A violently rotating column of air in contact with the ground,

indicated by either radar or report.

Snow

1" to 3” in 12 hours*

OR

Freezing Rain & Sleet

Ice accumulation < 0.25”

OR

at the forecaster's discretion

Ice accumulation

> 0.25” in 12 hours

Visibility

< ¼ mile

AND

Sustained Winds or Frequent Gusts

> 35mph for at least 3 hours which is accompanied by either snow or blowing snow

Sustained Winds

> 40 mph for at least 1 hour

AND/OR

Wind Gusts

> 58 mph for any duration

Sustained Winds

26 to 39 mph for at least 1 hour

AND/OR

Wind Gusts

between 40 and 57 mph for any duration

Visibility

< ¼ mile over a large area

Visibility

< ¼ mile over a large area

Temperature

< 32° for areas still in Freeze program

Temperature

33° to 36° during defined growing season

Red Flag Warning

for TN/NC

Red Flag Warning

for VA

Daytime Heat Index

>  110°F

OR

Temperature

> 105°F

Daytime Heat Index

> 105°F

OR

Temperature

> 103°F

Sustained winds (2 minute average)

> 18 mph

AND

relative humidities

< 25%

AND

rainfall < 0.25" over the past 2 days

Sustained winds (2 minute average)

> 20 mph

AND

relative humidities

< 30%

AND

10-hour fuel moisture observed or expected 

< 7%

See map and description of criteria below