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

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 Mar / 25th Last Updated: 03/21/18 2:42:01 PM

A chance of isolated severe thunderstorms in south-central KS, central OK, central and southwest TX


Very spotty severe thunderstorms will likely form along a dryline near San Angelo to Wichita Falls to west of Oklahoma City to Pratt KS

An approaching upper trough and jet streak provide some upper-air forcing, probably breaking the cap in places, and a surface low forming in southeast CO pulls low-level moisture toward the dryline

Any low-level jet seems weak and relatively dry low-level conditions hold down the tornado threat

Monday Mar / 26th Last Updated: 03/22/18 4:17:46 PM

Scattered severe thunderstorms in central TX, central and northeast OK

TORCON - 3 except 2-3 south-central OK

A chance of an isolated severe thunderstorm in east KS, northwest AR, west MO


Scattered severe thunderstorms develop along a dryline as an upper trough approaches and breaks an initially strong cap

Low-level jet will probably be relatively weak, and low-level humidity somewhat dry, holding down the tornado threat

A trough of low pressure developing northeastward from a low in southeast CO into northeast KS and beyond may pull enough moisture northward that a few severe thunderstorms can develop

Tuesday Mar / 27th Last Updated: 03/22/18 4:17:08 PM

Isolated severe thunderstorms and locally heavy rain in central and east TX, extreme south-central TX

TORCON - 2 to 3

Computer models differ, but a trough of low pressure may linger in central TX with low-level moisture and instability, but the low-level jet and upper forcing pull away into the Midwest where instability is too weak for severe thunderstorms

Friday Mar / 23rd Last Updated: 03/22/18 1:44:45 PM

Isolated severe thunderstorms in northeast KS, west-central MO, mainly in the evening and as a hail threat


A chance of isolated severe thunderstorms in adjacent areas of north-central KS, southeast KS, southwest and central MO

TORCON - less than 2

Relatively dry, capped air will probably prevent severe storms in the warm sector, but the additional lift from the warm front will probably allow elevated thunderstorms, some developing hail

The development of a surface low will probably give enough lift over the front for some storms to become severe

Saturday Mar / 24th Last Updated: 03/22/18 4:18:21 PM

A low chance of a thunderstorm with marginally severe hail by evening and overnight in north-central TX, south-central OK

TORCON - less than 1

Thunderstorms are possible in the Tennessee Valley, but instability seems too low for them to be severe


Isolated severe thunderstorms in central TX and south-central OK from near San Angelo to Fort Worth to Oklahoma City


A chance of an isolated severe thunderstorm in north-central and east OK, northeast TX

TORCON - less than 2

Isolated severe thunderstorms develop along a dryline as a weak upper trough and a jet streak approach

This forcing will probably allow an initially strong cap to be broken in a few places

Moisture will not be ample, but instability above the cap should be enough for hail to form

Discuss Torcon on Facebook