Timing

Forecasts can be submitted between 00Z to 16Z

Forecast verification will begin at 1630Z and goes through 1200Z the next day. Any tornadoes that happen before 1630Z do not count.

Forecasting will take place, Monday through Friday

Scoring

Scores are evaluated by comparing the distance between forecast points and tornadoes/warnings

Scoring will add up; more points are better

Verification will happen several days after the event

Forecast Submission

Use the email address and your name (provided at registration) to input a forecast

Choose "Yes Tornado" or "No Tornado" based on personal forecast techniques and intuition

If "Yes Tornado" is chosen, continue forward to input a latitude/longitude point

Abbreviations: Distance to tornado/damage report (DTT); Distance to warning (DTW); Maximum possible tornado score (MaxTor; 30 pts)

Calculating the Distance Component:

If DTT < 25 miles:

• Distance Component = (0.02255 * DTT^2)-(1.1248*DTT)+(MaxTor-0.9425)
• Exponential decrease in reward as you get further away... at 25 miles == 15 points

If DTT > 25 miles, but DTT < 100 miles

• Distance Component = ((-DTT*((0.5*MaxTor)/75))+(2/3*MaxTor))
• Linear decrease in the reward as you get farther away out to 100 miles

If DTT > 100 miles

• Distance Component=0

Calculating the Warning Component:

This is based off of the number of warnings you intersect or are near...

• Inside a warning (+8)
• Near a warning (+4), where the DTW ≤ 10 miles
• Example calculation: your forecast intersects 2 warnings and is near 1 more. Warning Component = (2*8) + (1*4)

Determining the "Lone Wolf":

If you are 100+ miles from the next nearest forecaster, and DTT < 25 miles: +30 points

Podium Component:

1st place = +12

2nd place = +8

3rd place = +4

When there are no tornado reports...

If you forecasted "No Tornado" you will receive points according to the SPC risk at 1630UTC

Forecast regions do not affect scoring. They offer forecasters the ability to explore their forecasting accuracy in different environments.