NWS declared tornado EF-1 near Biloxi Mississippi. (2) SONFIRE ALMANACS LLC on Twitter: "Tornado warning near Gulfport Miss. in which the model has indicated if rotation forms to the ground an EF-0 is possible." / Twitter The tornado was declared EF-1 which means that WALT Model 2 was only 6 miles per hour off on tornado winds and this is considered accurate.