Hurricane Erin made its closest approach to the U.S. at 2 a.m. EDT Thursday, when its center passed about 200 miles (320 km) southeast of the Outer Banks of North Carolina. At the time, tropical storm-force winds of the massive hurricane extended out about 230 miles (370 km) to the northwest of the storm. The U.S. Coast Guard Station at Hatteras recorded tropical storm-force winds much of Thursday morning, peaking at a sustained 42 mph, gusting to 53 mph.
At 2 p.m. EDT Thursday, Hurricane Erin was centered about 285 miles (455 km) east of Cape Hatteras, North Carolina, heading northeast at 18 mph (30 km/h). Satellite images showed that Erin was slowly degrading in appearance. The eye was no longer as prominent, and dry air was invading the southwestern portion of the storm. Erin’s top sustained winds had dropped to 100 mph (160 km/h), and the central pressure had risen to 952 mb.
Coastal flood threat from Erin peaks Thursday night
Despite the fact that Erin is now pulling away from the coast, significant coastal flooding will peak along the U.S. Mid-Atlantic coast during the Thursday evening high tide cycle. NOAA’s National Water Prediction Service is forecasting that Erin’s storm surge will bring major flooding at seven tide gauges during Thursday evening’s high tide, from northern North Carolina to southern New Jersey, including portions of Chesapeake Bay. According to Matt Lanza, writing at The Eyewall, Cape May, NJ, and Lewes, DE, are expecting their highest water levels since the “Snowzilla” nor’easter of January 2016.
Along the shores of portions of North Carolina, the Erin’s high waves will combine with a storm surge of two to four feet to produce damaging coastal flooding. Low-lying coastal highway NC 12 has already seen significant overwash and will be largely impassable during this evening’s high tide.
As documented by Michael Lowry, there were no active buoys located east of Erin’s center where its highest waves are, but buoy 41001, located about 30-40 miles west of the hurricane, did have waves topping 45 feet and pressures as low as 962 mb, a record for the station – besting the 969 mb pressure as Hurricane Sandy passed in 2012. Records at the buoy go back to 1976.
Forecast for Erin
Erin will gradually weaken and head north-northeastward and then northeastward out to sea, and will not trouble any other coastal areas. Erin is expected to become an extratropical cyclone on Saturday, a few hundred miles south of Newfoundland, Canada. Matt Lanza notes that Erin’s winds will bring enhanced wildfire risk in Atlantic Canada as it passes. The fire weather danger outlook is high to extreme in parts of Newfoundland, Nova Scotia, and New Brunswick, which have been experiencing moderate to severe drought.
90L near the Leeward Islands
A tropical wave located a few hundred miles east of the Leeward Islands was given the designation 90L by NHC on Thursday morning. The system was headed northwestward at about 20 mph (32 km/h) and will likely pass a few hundred miles northeast of the Leeward Islands on Friday, likely bringing the islands rains of 1-3 inches. While low wind shear and warm ocean temperatures near 29 degrees Celsius (84°F) are favorable for development, 90L is located at the southern edge of a swath of dry air associated with the Saharan Air Layer.
By Sunday, 90L is expected to turn more to the north, heading for a weakness in the steering flow left behind by Erin. As 90L progresses northward, the disturbance should encounter a moister atmosphere, and the models are quite bullish on 90L developing into a tropical depression or tropical storm by Sunday. This system may pass close to Bermuda on Sunday or Monday before recurving northeastward out to sea. In its 8 a.m. EDT Thursday Tropical Weather Outlook, NHC gave 90L two-day and seven-day odds of formation of 50% and 70%, respectively. The next name on the Atlantic list of storms is Fernand.
99L off the coast of Africa
A tropical wave in the far eastern Atlantic, a few hundred miles west-southwest of the Cabo Verde Islands, was headed west at about 10-15 mph (16-24 km/h). The system, designated 99L by the National Hurricane Center, has moderately favorable conditions for development, with sea surface temperatures near 28 degrees Celsius (82°F), moderate wind shear of 15-20 knots, and a moderately moist atmosphere with a mid-level relative humidity of about 65%.
Satellite images on Thursday showed 99L had a decent-sized area of heavy thunderstorms featuring plenty of spin at mid-levels of the atmosphere, but no signs of a surface circulation. A large area of dry air to the north, associated with the Saharan Air Layer, was impeding development and will likely continue to do so during the week. Increasing wind shear and a drying atmosphere are predicted for Friday through Sunday, making development after today unlikely; there is limited model support for the development of 99L over the next five days. In its 2 p.m. EDT Thursday Tropical Weather Outlook, NHC gave 99L two-day and seven-day odds of formation of 40%.
Central Atlantic tropical disturbance
A new tropical disturbance being tracked by NHC was located in the central Atlantic about 1,200 miles (1,930 km) southwest of the Azores on Thursday morning. The disturbance had a small amount of heavy thunderstorm activity, but a moderate amount of spin. High wind shear and dry air will impede development of the system as it moves slowly eastward over the next couple of days. In its 2 p.m. EDT Thursday Tropical Weather Outlook, NHC gave the disturbance two-day and seven-day odds of formation of 30%. This system is unlikely to be a threat to any land areas.
Bob Henson contributed to this post.
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