Hurricane trackers try to narrow ‘cone of uncertainty’
Hurricane Michael is likely to make landfall on the Florida Panhandle by Wednesday afternoon, creating potentially life-threatening conditions from the Alabama-Florida state line all the way eastward to the Suwannee River. Whether Michael lands near Tallahassee or closer to Panama City Beach, Dennis Feltgen of the National Hurricane Center told USA TODAY, everybody in the hurricane warning and watch areas should be on alert. “We don’t want anybody to get hung up on, ‘Well, is the storm going to go over this city or is it going over that city?’ – that’s immaterial here,” Feltgen said. “You need to be looking at the overall impacts of the hurricane.” Around the skinny black line used on tracker maps, representing the hurricane’s projected path, the “cone of uncertainty” shows the average track forecast error in the past five years. Feltgen said impacts, such as those from storm surge and inland flooding, extend outside that cone. The accuracy of track forecasts has improved in the past 10 to 15 years to the point where the five-day forecast for Hurricane Florence in September was off by only 2 miles. “Little wiggles” or variations in a storm’s track by 20 or 30 miles to the left or right can change impacts, Feltgen said. They cannot be predicted far in advance. To determine the track forecast for advisories issued every six hours, experts at the hurricane center use computer-generated models to process data collected by reconnaissance aircraft. Jets such as the NOAA G-IV sample the atmosphere around and ahead of the hurricane. Experienced specialists consider which models work best for different situations and factors, such as intensity. Hurricanes can change paths because surrounding weather patterns steer them. Hurricane Florence stalled when it made landfall because weather systems around it were in equilibrium. For Hurricane Michael, a distinct trough of low pressure in the middle and upper part of the atmosphere will push the storm, Feltgen said. “Unlike Florence, Michael will be on the move,” he said. “This is not going to be a lingering storm. This trough of low pressure will actually help guide the storm from the Florida Panhandle, up through Georgia, up through the Carolinas, and then push it out into the Atlantic.” The Pensacola News Journal, part of the USA TODAY Network, reported Monday that the National Hurricane Center predicted Michael to make landfall between Pensacola in the far western Panhandle and Apalachicola, directly south of Tallahassee on the coast. Officials in Bay and Walton Counties, both along the Panhandle, are among those that issued evacuation orders. Hurricane Opal, in 1995, was the last major hurricane to hit the two counties. Not including tourists, 130,000 were ordered to evacuate starting at 6 a.m. Tuesday, Joby Smith, chief of Bay County’s emergency management division, told USA TODAY. There were two shelters for general and special needs populations. If the storm makes landfall to the west, Bay County will face unprecedented storm surge concerns, particularly in bay system areas. If Michael comes through the east, severe weather will be the main issue. Either way, Smith said, the county will be worried about power outages and delayed emergency services. Panama City Beach is isolated by high-rise bridges that will close because of high winds. Low-lying areas are especially vulnerable.