Monday, August 10, 2009

Felicia now scheduled to hit O'ahu head-on

Once-hurricane Felicia's forecast track has taken another nudge northward and if it were still at hurricane strength, it would be Hawai'i's worst nightmare.

(Image, the Sunday night estimate of Felicia's track. Credit: NOAA.)

The track takes the strongest portion of the storm right over the heart of the Hawaiian chain, entering at Maui County and passing directly over O'ahu—the economic, political and transportation center of the state.

And it will spend a little more time blasting the Islands, as its forward speed has slowed.

“The latest track forecast continues to bring Felicia across the mid-section of the state. This may potentially bring flooding rains and strong gusty winds to many of the Hawaiian islands,” the National Weather Services says.

Tropical storm systems normally extend high into the atmosphere, but Felicia has lost much of its altitude. While low-level winds are pushing it from the east, upper-elevation winds are blowing from the west, and the combination has sheared the top off Felicia.

While it is weakening, the system is weakening very slowly, and is now expected to maintain tropical storm windspeeds all the way across the populated Hawaiian islands. It is forecast to enter the Hawaiian chain with 50-mile winds and leave the western end of the chain with 40-mile winds. Gusts will be higher.

At present, tropical storm-strength winds extend considerably more than 100 miles on either side of the storm center. The storm is moving forward at about 10 miles an hour, which means that if the center crosses your location, you're potentially facing as much as 20 hours of tropical storm-force winds—along with the associated heavy rain.

Based on the storm route in the 2 a.m. forecast today, Big Island residents should be feeling the effects of Felicia tonight (Monday, 8/20), Maui County tonight and early tomorrow, and O'ahu much of the day Tuesday and Tuesday night. Kauai can expect storm conditions most of the day Wednesday.

Caveat: That's based on our calculations. The weather service has not been making those timing predictions.

And once again, it's not just the wind, but the rain. Even if winds taper off, the rain associated with this storm system will likely be very heavy.

“Regardless of the intensity of Felicia when it reaches the Hawaiian Islands, locally heavy rainfall is still expected to occur and flash flooding remains a possibility,” the weather service says.

© Jan TenBruggencate 2009

No comments: