By: Jeff Masters and Bob Henson , 2:03 PM GMT on October 13, 2016 From Weather Undeground

Category 3 Hurricane Nicole is pounding Bermuda after putting on an impressive round of rapid intensification that saw the hurricane top out as a Category 4 storm with 130 mph winds early Thursday morning. At 10 am EDT (11 am ADT) Thursday, satellite imagery and radar from the Bermuda Weather Service showed that the western edge of Nicole’s large roughly 40-mile diameter eye was poised to move over the eastern end of the island by 11 am EDT. The northern eyewall of Nicole is the strongest part of the storm, and Bermuda began taking a wicked pounding from this powerful northern eyewall beginning around 9 am EDT. The Bermuda airport is located on the east end of the island, and at 9:55 am EDT measured sustained winds of 77 mph (10-minute average), gusting to 104 mph. An Air Force hurricane hunter aircraft is in Nicole, and at 9:30 am EDT found top surface winds in the northern eyewall of 102 mph. The plane did not sample the most intense part of the northern eyewall, though, and Bermuda is likely to experience higher winds than that. High wind shear is attacking Nicole and will weaken the storm today, but probably too late to provide much relief to Bermuda.
Figure 1. Hurricane Nicole as seen by the Bermuda radar at 9:44 am EDT October 13, 2016, when the northern eyewall was battering the island. Bermuda (under the white cross) was about to enter the eye. Image credit: Bermuda Weather Service.

Wind and storm surge damage the main threats
The main threat from Nicole is wind damage, as the island has rarely experienced the winds from a Category 3 hurricane. Storm surge is also a concern, as Nicole is expected to drive a storm surge of 6 – 8 feet to Bermuda. Fortunately, this surge will be arriving as the tide is going out. High tide was at 6:36 am (ADT) this morning, and low tide will be at 12:48 pm (ADT) this afternoon. The difference between low tide and high tide is about three feet, so the island would have had about an extra two feet of inundation had Nicole hit at high tide. See the Bermuda Esso Pier, St. Georges, Bermuda Tide Chart (thanks to WU member SPShaw for this link.)
Figure 2. Latest satellite image of Nicole.

Another missed rapid intensity forecast
Nicole put on its rapid intensification burst as it passed over the near-record-warm waters of the subtropical North Atlantic, with sea-surface temperatures of 29°C (84°F)— roughly 2°C above average. Given the warm waters and light wind shear the storm had, rapid intensification was not a big surprise, but Nicole’s rapid intensification from a tropical storm on Tuesday morning to a Category 4 hurricane Wednesday night was not anticipated by our top three intensity models—the HWRF, SHIPS and LGEM. The Tuesday morning runs of these models all predicted that Nicole would be a Category 1 hurricane at the time of its closest approach to Bermuda on Thursday morning. NHC did go higher in their Tuesday morning intensity forecast, calling for Nicole to be a Category 2 storm by Thursday morning, but their intensity forecast fell far short of predicting the actual rapid intensification that occurred. A similar situation occurred for Hurricane’s Matthew’s rapid intensification from a tropical storm to a Category 5 hurricane in the Caribbean, which was poorly forecasted by the intensity models and NHC. Hurricane intensity forecasting still has a long ways to go, unfortunately.

A rarity for Bermuda
It’s not every day that Bermuda sees a hurricane, and it’s even more uncommon for a major hurricane to target the island directly. In a local survey going back to 1609, the Bermuda Weather Service found that tropical cyclone damage was recorded about once every 6 to 7 years. From 1900 to 2007, the only direct hits cited by the agency were the Havana-Bermuda Hurricane of 1926, the Miami Hurricane of 1948, and Hurricane Arlene (1963). Of course, a hurricane can cause havoc while passing just west or east of the island as well. According to Phil Klotzbach (Colorado State University), only one Category 4 hurricane is known to have tracked within 50 miles of Bermuda in records going back to 1851: Hurricane 5, on October 16, 1939. Nicole will fall just short of reaching that milestone, at least in the initial analysis, as it was downgraded from Category 4 to Category 3 at 7:00 am EDT Thursday while located about 55 miles southwest of Bermuda.

In the big picture of Atlantic hurricane seasons, Nicole is also a standout. It follows Hurricane Matthew, which attained Category 5 strength on October 1. Never before has the Atlantic recorded two storms of at least Category 4 strength in October, according to Klotzbach (again, in records going back to 1851). Nicole attained its Category 4 strength at 30.1°N, making it the latest Atlantic storm in the season to exhibit Category 4 strength that far north since Hazel (1954), which was a Cat 4 at 30.2°N.

Keep an eye on the Southwest Caribbean next week
A broad area low pressure is expected to form in the waters of the Southwest Caribbean off the coast of Nicaragua early next week. The computer models have been very inconsistent in their predictions on the potential timing and location of any tropical storm development that may occur in this region, but we will have to keep an eye on it.
Figure 3. This image from the 06Z Thursday run of the GFS model shows winds exceeding 52 mph (60 mph) approaching the western Washington coast late Saturday in association with a 963 millibar low that forms from the remnants of Typhoon Songda. Image credit: tropicaltidbits.com.

Pacific Northwest bracing for the remnants of Typhoon Songda
Another high-latitude anomaly of the tropical type will make its presence felt in the U.S. Pacific Northwest and far southwest Canada this weekend. Typhoon Songda reached its peak intensity on Tuesday at an unusually far northerly latitude: 30.3°N in the Northwest Pacific, where it briefly became a super typhoon with top sustained winds of 150 mph. No longer classified as a tropical cyclone, Songda remained a powerful storm in the North Pacific on Thursday morning, whipping eastward through the North Pacific near the International Date Line just north of 40°N with a central pressure of 996 millibars. Songda will be incorporated in a train of storms heading into the Pacific Northwest, and models agree that it will deepen at least into the 960 – 970 mb range as it approaches the Olympic Peninsula of Washington (or perhaps a bit further south, if the ECMWF model proves correct]. This is a classic set-up for very heavy rain and damaging winds across western Oregon and Washington, including the Seattle area. High wind warnings are already in effect from tonight to Friday for western Oregon and Washington, where gusts may reach 75 mph along the Oregon coast, 60 mph along the Washington coast, and 55 mph in the Seattle area. Even stronger winds are liable to materialize late Saturday and/or Sunday as the remnants of Songda approach. We’ll have more details on this potential major event on Friday.

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