Storm Weakens After Peaking Near Major Hurricane Strength

Yesterday, the Atlantic almost had its first major hurricane of the season.  Hurricane Gordon, which had become a hurricane during the early part of the day, suddenly ramped up from a minimal hurricane at 2:00 PM EDT to a Category Two storm with 110 mile per hour winds at 8:00 PM EDT.  It was a jump of 30 miles per hour in wind speed in just six hours, and an increase in strength from a strong tropical storm to near major hurricane in about 30 hours.  Minimum central pressure dropped some 32 millibars or 0.94 inches in 39 hours.

Gordon stayed on the cusp of becoming a Category Three Hurricane on the Saffir-Simpson Scale for nine hours from Saturday evening to early Sunday morning despite the marginal sea surface temperatures of 26 degrees Celsius, or about 79 degrees Fahrenheit.  However, beginning at 5:00 AM on Sunday morning, Gordon began to gradually weaken with maximum sustained winds first dropping to 105 miles per hour, then 100 miles per hour by the 11:00 AM EDT Advisory, and then 90 miles per hour by the 2:00 PM EDT Advisory.

Despite the weakening, Hurricane Gordon is still expected to remain a hurricane by the time it makes its closest approach to the Eastern Azores on Monday.  As of the most recent advisory, Gordon was located some 220 miles to the Southwest of Sao Miguel Island in the Azores.  In addition to undergoing some strengthening since the last time I reported on the storm yesterday, Gordon has also picked up forward speed, and is now moving to the East-Northeast at 21 miles per hour.  Minimum central pressure has risen 11 millibars, or 0.32 inches to 976 millibars, or 28.82 inches of Hg (Mercury).

The government of Portugal upgraded the Tropical Storm Warning that was in effect for the Central and Eastern Azores to a Hurricane Warning for those islands yesterday afternoon.  Since that time, the warning has been amended to only include the Eastern Azores.  The latest forecast discussion indicates that Gordon did have a clearly defined eye, but it had begun to become less visible during the late morning hours on Sunday.  Wind shear as high as 30 knots or 35 miles per hour is also beginning to take effect on the storm by giving it a more baroclinic look with a tilt toward the east.

The NHC SHIPS forecast indicates that Gordon will weaken to below tropical storm strength by late Monday morning and then became extratropical or post-tropical by the same time on Tuesday.  Elsewhere in the tropics, the disturbance in the Eastern Atlantic continues to get better organized, and the NHC has upgraded the probability of formation to 70 percent over the next 48 hours.