September 2, 2011

Tropical Weather Outlook

Summary:

D #13 is nearly stationary, drifting slowly toward the north around 1mph.

Computer models have come into better agreement, and most models along with the official forecast indicate that TD 13 will meander slowly north or northwest through the next 24 hours. High pressure currently north of the system is forecast to move eastward, which will allow for a more north and northeast movement beginning Saturday.

On the forecast track, the storm will move inland over southern Louisiana on Monday, but the much of the Florida Panhandle, west of Tallahassee, lies within the 5 day error cone. Tropical Storm Warnings are in effect from Pascagoula, Mississippi to Sabine Pass, Texas.

It is too early to tell if this system will have a direct impact on Florida, but it should be monitored over the next couple of days. Regardless of the track, TD 13 will at least be responsible for increasing tropical moisture across the state and allowing for higher chances of rain this weekend and early next week.

The chance of receiving tropical storm force winds in Florida is less than 20%.

Heavy rainfall will be the main concern and the slow movement of the storm could produce rainfall amounts as high as 5-10 inches, with locally higher amounts, across the western Florida Panhandle and between 2 and 6 inches across the eastern Panhandle and Florida Big Bend. This rainfall could come in a short period of time, resulting in flash flooding and river flooding concerns. Flash Flood Watches are likely for portions of Northwest Florida by Labor Day.

In addition, increasing winds and ocean swells will increase the threat for high waves and rip currents along the Florida Panhandle coast. High Surf Advisories are in effect west of Destin, Florida.

At 5am ET Friday, Tropical Storm Katia was located over the central Atlantic about 750 miles east of the Leeward Islands, or about 1,920 miles east-southeast of Miami, Florida.

Maximum sustained winds remain near 70mph, but Katia is expected to regain hurricane intensity within the next 48 hours and could still become a major hurricane by Wednesday of next week.

Tropical Storm Katia is now moving west-northwest around 15mph, but a turn to the northwest along with a decrease in forward pace is expected through the next 2 days as it is steered into a weakness in a high pressure ridge over the central Atlantic.

Most computer models remain in good agreement on the system and these models along with the official 5-day forecast track from the National Hurricane Center keeps the system over the central Atlantic away from any land masses through the next 5 days.

Long range computer models continue to indicate that Katia may move back towards the west-northwest next week as high pressure builds in the western Atlantic, but may still be steered north later next week.

However, computer model tracks have been trending westward and still bears watching through the weekend. Even if the storm stays away from the U.S., ocean swells from the storm could affect the Florida East Coast next week.


Amy Godsey, State Meteorologist
Florida Division of Emergency Management


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