ProbSevere Suite Helping on Busy Severe Weather Day

A very active severe weather day continues over the NWS CWAs our teams are covering today (OUN, TSA, SGF).  A couple highlights from quick discussions with forecasters relate to ProbSevere suite of products:

• ProbTor is especially useful to draw attention to storms that might be rapidly increasing their tornadic potential, especially when busy interrogating many storms and issuing warnings.
• ProbHail on a storm over southern OUN CWA was indicating 75% probabilities, but the MESH was low biased (under an inch).  The storm was reported to have produced golf ball sized hail.  The forecaster viewed the high ProbHail value as a demonstration of the value of additional information included in the ProbHail model.  (The forecaster suspected low MESH due to updraft tilt, which is a known source of low bias.)
• One forecaster changed the ProbSevere double contour threshold from 3% to 10% given the very favorable environment for tornadoes in his CWA today (SGF).  The customizability was viewed very positively as that changed greatly decluttered his display.
• ProbTor jumps are proving very useful in highlighting storms with rapidly increasing tornadic threat (e.g., a storm in the SGF CWA had ProbTor jump from 37% to 74% in 8 min as the storm developed a TDS and had ground reports of tornadoes).

-J. Sieglaff