Hurricane Bill is turning into one of those hurricanes. You know, the ones that impress you with size and strength, but start to disappear before you’re really ready. Look across the Atlantic or East Pacific. Study the MJO. Bill will be the last for several days. Or until the next one shows up. Whichever comes first. How’s that for a forecast? Bill is very ragged and losing intensity. The storm is also moving more northerly. Just as the NHC forecast. Yawn.Bill, though still a major hurricane this morning, is not the same storm we saw yesterday or the day before. Upper-level wind shear and dry air are really getting to the system. The eye is gone. The hurricane is assymetrical with the coldest cloud tops everywhere but the western quadrant. It’s all downhill from here for Bill.
Hurricane Bill Water Vapor - Aug 21, 2009 courtesy RAMSDIS
Dry air is to the south of the hurricane and the only thing between Bill and the oncoming trough running to the rescue of the eastern seaboard is a weak upper level low moving southeast. Furthermore, water temperatures will be steady throughout the day before starting to cool. It’s highly unlikely Bill will resemble it’s former self. As the hurricane begins to interact more with the trough a stream of moisture will start to spread north/northeast from the hurricane as the hurricane itself will likely become highly elongated on a south/southwest to north/northeast axis. Forward speed should pick up a bit, also.
Hurricane Bill Forecast #24, courtesy NRL Monterey
Bills current bearing – something I’ve apparently LOVED to mention with this storm – is 315° or due northwest. This should continue to increase over the next 24 hours to due north as the hurricane rounds the western edge of the high pressure ridge steering it. It can be reasonably safe to assume Bermuda will see little effect from Bill. The Mid-Atlantic and New England states are relatively clear. The focus now shifts to areas such as Nova Scotia and Newfoundland. The National Hurricane Center is expecting a minor category one hurricane to make landfall around St. Pierre. Other areas likely to see hurricane conditions include Sydney, Glace Bay, Grand Bank and Mt. Pearl. St. Pierre, Grand Bank and Mt. Pearl are likely, based on the current forecast, to actually get the worst conditions as the hurricane races by.
Other Tropical News
We’ve been seeing a supression of activity (besides Bill) in both the Atlantic and East Pacific. Upper-level conditions that had been present over the past couple of weeks have since changed for the worse thus there has been little development. There is quite a bit of subsidence across both basins which has kept any potential development to a minimum. The National Hurricane Center is watching one system near 15N, 132W. Quickscat imagery shows a closed surface circulation but weak winds. It’s possibly this system may develop as it moves into the Central Pacific Basin.
East Pacific Basin IR - Aug 21, 2009
Otherwise, expect very little natural development in either basin over the next week to week and a half. The Madden-Julian Oscillation (MJO) index shows the best chances for tropical development are located primarily in the Indian Ocean while the West Pacific has seen a bump in activity; what else is new?
Madden Julian Oscillation Index - Aug 19, 2009
