|Chance of a tornado within 25 miles of any point|
A strong, amplified 300mb jet stream will be pushing eastward, adding a lot of energy to the system responsible for this event. The system will be up near Nebraska. Increasing the system strength increases the surrounding wind field, thus increasing rotation and instability potentials. The storms will begin when the dryline begins to shift east to try and escape the oncoming cold front from the west (which will not happen). With up to 3000 j/kg of instability and over 3 on the EHI index, expect storms that form to quickly become tornadic.
Initiation, or the initial occurrence, of these storms has been sort of a gray area in recent days. Here is the latest initiation graphic from the National Severe Storms Laboratory (NSSL)'s personal WRF model.
I have circled the area where the strongest storms are expected to be at 7:00 PM CDT tonight. Now, this is what I see as the initialization of strong to severe storms. But see below's actual initiation graphic.
Here is my tornado graphic.
|Blue: Low risk for tornadoes|
Dark blue: Moderate risk- a few weak tornadoes
Purple: Substantial risk- many weak-moderate tornadoes
Green: Dangerous risk- several strong tornadoes expected