Hilary Update: Thursday’s Swell Slightly Upgraded

As of 8:00 p.m. PDT on Tuesday, September 27, 2011 (NHC Advisory #28): Hurricane Hilary has begun its northwestward turn, with an initial motion estimate of 310° at 7 mph. As expected, the hurricane has also begun to weaken with maximum sustained winds now in the 110 mph range (Category 2). Rapid weakening is likely after 24 hours, as Hilary encounters cooler sea surface temperatures and increasing southwesterly shear.

The latest Point Loma Wavewatch forecast has been slightly upgraded, with the south swell now expected to peak Thursday evening at 4.3 feet at 12 seconds (179°). The slight Sunday reinforcement from the previous model run has vanished, likely the result of Hilary’s rapid weakening.

Wednesday will see combo-swell conditions, with WNW, SSW, and SSE components all within the 2-3 feet at 12-15 second range in the water at once. The WNW and S swells linger into Thursday, with the prior fading slowly throughout the day as the south swell builds towards its evening peak.

Both swells decline rather quickly on Friday, with biggest conditions early. By Saturday there won’t be much left except some short-period south (2.3 feet at 9 seconds 179°).

Keep an eye on the models over the next 24-hours, as there has been a steady upward trend during the last few days. The SSE swell from Hilary should begin to show in the real-time reports by Wednesday afternoon, so keep an eye on @buoy46232 tomorrow to see how the observed conditions stack up against the forecast.