Example convective outlook map. Notice the new dark green “MRGL” (marginal) and orange “ENH” (enhanced) risk areas.

The National Weather Service Storm Prediction Center (SPC) plans significant changes to its Convective Outlook product, from which many SKYWARN storm spotters and others get their first indications that severe weather could occur.

The SPC plans to expand the product’s risk categories from four to five, while clarifying the category previously labeled as “See Text.” Convective outlooks would instead have a new “marginal” category to denote areas with at least a five percent probability of severe weather. The upper end of the current “Slight Risk” category would be renamed “Enhanced” (short for “Enhanced Slight”) to denote a threshold 30 percent probability of severe wind or hail and/or a 10 percent chance of a tornado during the Day 1 period. For Days 2 and 3, the “Enhanced” risk category would denote a 30 percent total severe probability. The Moderate and High risk thresholds will remain essentially unchanged.

The SPC wants users of the Convective Outlook product, including storm spotters, to provide their opinions on the planned changes. Read details about the changes on the SPC website, where you can also follow a link to a survey.