Analysis of a Long-Range Tornadic Debris Signature Caused by a Violent Tornado in Havana, Cuba

Shortly after 0100 UTC on 28 January 2019, a rare, violent tornado struck northern portions of Havana, Cuba. Four deaths and 195 injuries were reported. The large-scale pattern featured a deep, anomalous shortwave trough extending from the southeastern United States to the Yucatan Peninsula. A broad area of low pressure at the surface formed northwest of the Florida Keys over the southeastern Gulf of Mexico, with the warm sector enveloping Cuba and South Florida. Around sunset, storms initiated along the associated cold front as it marched eastward toward Cuba and the Florida Keys. Storm intensities in the Keys remained below severe limits. However, storms were much more robust over Cuba and the Straits of Florida. GOES-East infrared imagery observed overshooting tops, as cold as -60 degrees Celsius, as the storms approached Havana. In addition, Key West WSR-88D imagery indicated a supercell with rotational velocities peaking at 21.9 m/s (42.5 knots) and forward velocities of 36-44 m/s (70-85 knots). These values were detected by the Key West WSR-88D on Boca Chica Key, over 160 km (100 miles) away. At this distance, the 0.5-degree tilt scanned near 3.0 km (10,000 feet) above mean sea level (MSL). Despite this altitude, a tornadic debris signature (TDS) was present with correlation coefficient values as low as 0.60 (collocated with the velocity couplet). This TDS was still evident at 0.9 degrees, scanning near 4.3 km (14,000 feet) above MSL. Tornado intensity estimation guidance derived from a four year dataset of 181 TDS producing tornadoes suggests that this signature is associated with at least EF2-EF3 damage (WDTD 2015). This estimate was confirmed by staff from the Cuban Meteorological Institute, who surveyed EF4 damage. This tornado presents a rare opportunity to evaluate a TDS that occurred over 160 km (100 miles) from the nearest dual-polarization capable weather radar, providing confirmatory evidence of operational tornadic intensity guidance.