The TOR:CON Index
from Dr. Greg Forbes' Facebook Page

Severe Weather Expert, Dr. Greg Forbes developed the TOR:CON index to estimate the risk of a tornado on a given day or night near your area.

The TOR:CON index ranges from 0 to 10. Multiply the value by 10 to get your percentage chance of a tornado within 50 miles of a location. For example, a TOR:CON index of 6 means there's a 60% chance of a tornado within 50 miles of any location in the indicated area.

Note: By definition, a severe thunderstorm contains one or more of the following: hail at least 1 inch in diameter, wind gusts 58 mph or higher, or a tornado.

TOR:CON Value Descriptions

8+
Very high probability of a tornado
High probability of a tornado
Moderate chance of a tornado nearby, but hail and/or high wind gusts possible
Low chance of a tornado, but hail and/or high wind gusts possible
Near-zero chance of a tornado or a severe thunderstorm

Sunday Jul / 8th Last Updated: 07/06/18 3:36:02 PM

Isolated severe thunderstorms in north MN, southeast ND, northeast and central SD

TORCON - 2

Computer models differ, but there is a chance that a tropical cyclone could affect eastern NC

Convergence along a frontal zone should focus a few severe storms, but lack of upper forcing and relatively air and high cloud bases hold down the tornado threat

Monday Jul / 9th Last Updated: 07/06/18 3:35:37 PM

A chance of severe thunderstorms ahead of a cold front in south MI, northwest OH, north and central IN, central IL, possibly east-central MO

TORCON - 1

A chance of severe thunderstorms along a stationary front in northeast WY, southwest SD, northwest and north-central NE

TORCON - 1

Computer models differ, but there is a chance that a tropical cyclone could affect eastern NC

Tuesday Jul / 10th Last Updated: 07/09/18 12:04:19 PM

A chance of severe thunderstorms along a weak cold front in ME, NH, VT, central, south and west NY, west MA, PA except southeast, north and central OH, central IN, central IL

TORCON - 1

A chance of a severe thunderstorm in east MT, northwest ND

Computer models differ, but there is a chance that a tropical cyclone could affect eastern NC

An upper trough induces a surface low in east MT, but relatively dry conditions hold down the severe threat

Weak low-level winds hold down he severe threat in the Midwest and Northeast, as does the weak nature of the frontal trough

Wednesday Jul / 11th Last Updated: 07/06/18 3:34:36 PM

Isolated severe thunderstorms in northwest MN, southeast ND, northeast and central SD

TORCON- 2

Computer models differ, but there is a chance that a tropical cyclone will affect part of the Mid-Atlantic coast

A few severe thunderstorms may form along a trough of low pressure in the Northern Plains, but the upper forcing seems to go mainly into Canada and low-level winds weaken

Relatively dry conditions also hold down the severe threat

Thursday Jul / 5th Last Updated: 07/05/18 2:39:26 PM

A chance of isolated severe thunderstorms in VT, NY except southeast, PA, OH, south MI, IN except extreme south, central IL, north WV, west MD

TORCON- 1

A chance of severe thunderstorms along the foothills in east WY, east CO, northeast NM

TORCON - 1

Low-level and mid-level winds are quite weak, so severe thunderstorms should be of the pop-up type (pulse-type with microbursts) due to unstable air ahead of a cold front in the Midwest and Mid-Atlantic and over the Front Range of the Rockies

Friday Jul / 6th Last Updated: 07/09/18 12:04:19 PM

A chance of severe thunderstorms in east ME, southeast NH, central and east MA, east CT

RI, Long Island, central and south NJ through early afternoon

east MD, DE, VA, east WV, southeast KY, north-central and northeast TN, north NC, DE, DC

TORCON - 1

A cold front is heading across the Northeast, but may clear most of the New England coast early enough that instability will be limited

Winds south of New England are weak at all levels, so any severe storms should be of the pop-up (pulse) variety with spotty localized microburst winds and locally heavy rain

Saturday Jul / 7th Last Updated: 07/09/18 12:04:19 PM

Isolated severe thunderstorms probably beginning in the evening and continuing overnight in south and east ND, north MN, northwest SD, possibly extreme southeast MT and extreme northeast WY

TORCON - 2 to 3, especially for any storms that form in the evening

Storms will likely form in a trough of low pressure over the region in the evening and overnight as a weak upper trough heads toward the region north of an upper ridge

Moisture seems limited and some capping aloft, which should limit the tornado threat despite a developing low-level jet

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