THE BARON TORNADO INDEX BTI Presented by Matt

THE BARON TORNADO INDEX (BTI) Presented by: Matt Havin

The Baron Tornado Index WHAT IS THE BTI? An integration of the latest available mesoscale model data combined with singlesite radar data, used for advanced analysis of storms during potentially tornadic events 11/23/2020 Matt Havin 2

The Baron Tornado Index HOW DOES IT WORK? The BTI ranks each storm for tornadic potential in the continental U. S. on a 1 -10 scale, all in real-time. Weak storms are rated a 1, and the strongest storms with a likely tornado are rated a 10. 11/23/2020 Matt Havin 3

The Baron Tornado Index WHAT METEOROLOGICAL DATA IS USED TO PRODUCE THE BTI? › Data is taken in real-time from every NWS radar site within the continental United States (CONUS) › From this radar data, all storms in CONUS are identified and ranked based upon a variety of attributes, including: � Reflectivity � Velocity � VIL (hail cores) � Baron shear markers � Additional radar attributes 11/23/2020 Matt Havin 4

The Baron Tornado Index WHAT METEOROLOGICAL DATA IS USED TO PRODUCE THE BTI? › After ranking the storms from the radar data, we then look at numerical model data to determine if the mesoscale environment is conducive for tornadoes › We currently use the operational Rapid Update Cycle (RUC) from NCEP for model data, and will switch to the Rapid Refresh (RR) in 2010 › To match up the real-time radar data of the storm to that of a numerical model, we do an interpolation of the model data down to 1 minute increments 11/23/2020 Matt Havin 5

The Baron Tornado Index WHAT METEOROLOGICAL DATA IS USED TO PRODUCE THE BTI? › When looking at the RUC model data, there a few numerical model products that we focus a lot of attention on when looking for tornadoes › Research performed by meteorologists at the Storm Prediction Center, the NWS, and in the private sector, has shown that the majority of tornadoes occur with CAPE between 1500 -3500 J/kg, 01 km SRH values between 150 -300 m 2/s 2, and LCL heights below 1300 meters 11/23/2020 Matt Havin 6

The Baron Tornado Index WHAT METEOROLOGICAL DATA IS USED TO PRODUCE THE BTI? › After processing both the radar (NEXRAD) and model data (RUC), we then produce a BTI number for all the storms in the continental U. S. › We are able to do this using algorithms developed from performing hundreds of tornado case studies that looked at all these pieces of data 11/23/2020 Matt Havin 7

The Baron Tornado Index HOW LONG HAS IT BEEN OPERATIONAL? WHAT SUCCESSES HAS IT HAD SINCE ITS RELEASE? The BTI has been used in the broadcast industry since Jan. 2008. The first tornadic event that the BTI was used in was the Super Tuesday tornado outbreak on Feb. 5 th, 2008, where it pinpointed numerous deadly tornadoes across much of the South. 11/23/2020 Matt Havin 8

The Baron Tornado Index GEORGIA TORNADOES – FEB. 18 TH The BTI hit 7+ on several different tornadic storms on the night of February 18 th. The EF-2 tornado that passed south of Peachtree City had a 7. 4 BTI before touchdown, and tracked for 20 miles. 11/23/2020 Matt Havin 9

The Baron Tornado Index MURFREESBORO, TENNESSEE – APRIL 10 TH On Good Friday, a fatal tornado rated EF-4 struck Murfreesboro. The BTI hit 9. 4 more than 10 minutes before the tornado first touched down. The tornado tracked over 23 miles and reached ½ mile wide. 11/23/2020 Matt Havin 10

The Baron Tornado Index LAKE GUNTERSVILLE, ALABAMA – APRIL 10 TH A long-track tornado rated EF-3 crossed Lake Guntersville just after 3 PM on Good Friday. The tornado caused extensive damage to lake houses on Preston Island during the 28 mile track. 11/23/2020 Matt Havin 11

The Baron Tornado Index LAKE GUNTERSVILLE, ALABAMA – APRIL 10 TH A long-track tornado rated EF-3 crossed Lake Guntersville just after 3 PM on Good Friday. The tornado caused extensive damage to lake houses on Preston Island during the 28 mile track. 11/23/2020 Matt Havin 12

The Baron Tornado Index GOSHEN COUNTY, WYOMING – JUNE 5 TH An EF-2 tornado was tracked by the VORTEX 2 team on the afternoon of June 5 th. Doppler on Wheels measured wind speeds of 130 mph near the ground. BTI hit 7. 1 at the time tornado was first spotted. 11/23/2020 Matt Havin 13

The Baron Tornado Index GOSHEN COUNTY, WYOMING – JUNE 5 TH An EF-2 tornado was tracked by the VORTEX 2 team on the afternoon of June 5 th. Doppler on Wheels measured wind speeds of 130 mph near the ground. BTI hit 7. 1 at the time tornado was first spotted. 11/23/2020 Matt Havin 14

The Baron Tornado Index STRATEGIES FOR USING THE BTI EFFECTIVELY ON THE AIR › Look for high BTI values (7 -10), especially on an isolated storm or supercell. � Example: May 10 th, 2008 - Stuttgart, AR storm with a BTI of 10 produced 20+ mile long-tracked tornado that produced EF-3 damage › Comparison of all BTI values in your DMA (one storm has 5 BTI, ten other storms have a 2 BTI) � Example: April 10 th, 2008 - Southeast Iowa stacked low pressure event. Many tornadoes with BTI of 4 -6, and all others storms with BTI of 1 -3 and no tornado › Increasing trend in BTI (storm going from BTI of 3 to 5 to 7 within 15 minutes) � Example: March 14 th, 2008 – downtown Atlanta tornado rapidly increased from 3 BTI to 7 BTI and produced the tornado soon afterwards 11/23/2020 Matt Havin 15

The Baron Tornado Index WHEN TO EXERCISE CAUTION WHEN USING THE BTI Always keep in mind that the BTI is an automated tornado detection algorithm. Like anything else in the weather world, it is far from perfect. Here are common situations where the BTI may not detect tornadoes: › › 11/23/2020 Tropical storms/hurricanes Tornadic features often too small/atypical to be detected by NWS NEXRAD radar…which lowers BTI. Cold-core low pressure systems Marginal CAPE (<500 J/kg) and lowtopped mini-supercells make the overall tornadic potential look less likely, which lowers the BTI. However, somewhat useful when looking for relative BTI values between 2 -5. Matt Havin 16

The Baron Tornado Index LEADING THE NEXT GENERATION OF TORNADO DETECTION IMPROVEMENTS › › › The BTI was introduced to the broadcast industry nationwide in January 2008, and has already proven to be highly effective at detecting a storm ripe for tornado development with lead times of 1530 minutes on numerous occasions Upcoming model improvements, such as the replacement of the RUC with the Rapid Refresh model in 2010, should help meteorologists and the BTI be more effective at identifying potentially tornadic events Improvements in radar technology, such as the upcoming dualpolarimetric NEXRAD upgrade by L-3 Communications and Baron Services, should help lower false alarm rates and improve lead times beyond the limits of currently available technology 11/23/2020 Matt Havin 17