Summary:
· At 5pm EDT Monday, Gordon lost tropical characteristics in the far northeastern Atlantic and the NationalHurricane Center has discontinued advisories on the storm.
· At 5am Tuesday, the large tropical area of low pressure in the central Atlantic Ocean, designated as 94L, has acquired enough thunderstorm activity near the center of circulation to be classified as Tropical Depression Nine.
· At 8am EDT Tuesday, T.D. 9 was located about 645 miles east of the Leeward Islands, or approximately 1,978 miles from Miami, Florida.
· Maximum sustained winds are around 35mph and T.D. 9 is moving westward at 20 mph.
· This general motion is expected to continue for the next 2-3 days as it is steered around the southern edge of a large high pressure system in the central Atlantic Ocean.
· Computer model track guidance is in good agreement and these, along with the official NHC forecast, take T.D. 9 across the Leeward Islands Wednesday and emerging over the eastern Caribbean Sea Wednesday night or Thursday morning.
· Beyond that time, high pressure should weaken, which will allow T.D. 9 to curve northwest towards or just south of Hispaniola or eastern Cuba. If it interacts with the mountainous terrain, it could slightly weaken the system. Some models have it curving earlier, moving towards the Bahamas.
· Although it will have to interact with some moderate wind shear and dry air, conditions are favorable enough to promote strengthening.
· Computer models intensity guidance is in less agreement, with some models keeping T.D. 9 weaker and others rapidly strengthening it into a major hurricane. The National Hurricane Center is predicting that T.D. 9 will become Tropical Storm Isaac later today and a hurricane once it moves into the Caribbean Sea.
· It is important to note that computer model guidance can be unreliable until a stronger system develops.
· NOAA Hurricane Hunter aircraft are scheduled to investigate this system this afternoon. Data from this reconnaissance mission may help computer models get into better agreement.
· Elsewhere, shower and thunderstorm activity associated with an elongated area of low pressure (95L) in the western Gulf of Mexico have not changed in organization.
· Although this disturbance is located close to land, some gradual development of this system is possible as it slowly drifts westward during the next day or so. The National Hurricane Center has given this system a medium (30%) chance of developing by Thursday.
· Hurricane Hunter aircraft is scheduled to investigate the system this afternoon.
· Further east, a tropical wave and associated area of low pressure in the eastern Atlantic (96L) is showing signs of organization.
· Additional development is possible through the next few days as it moves westward at 15 mph, and the National Hurricane Center is now forecasting a high (60%) chance of becoming a tropical cyclone within the next 48 hours.
· Computer model guidance is in good agreement and take this system on a west-northwest track through the central Atlantic, moving north of the Leeward Islands in 7-9 days. Most models also intensify the system into a tropical storm within the next 5 days. The next name on the 2012 storm list is Joyce.
Florida outlook:
· It is too early to tell if T.D. 9 will affect Florida. Everyone should continue to closely monitor this system.
· There are no tropical watches or warnings in effect for Florida. Although Florida is not yet within the error cone, portions of South Florida have a 3-5% chance of receiving tropical storm force winds within the next 5 days.
· A stalled cold front will continue to produce above normal rain chances and heavy rainfall across portions of North and Central Florida today.
· Rain totals of 2-4 inches may occur today with locally higher amounts of 4-6” possible.
· A Flash Flood Watch remain in effect for the eastern Florida Big Bend through this evening. A Flood Watch is also in effect for Northeast Florida and the Nature Coast through 8pm.
· Run-off from daily rainfall may continue to move into already swollen rivers and there is a chance that some North and West Central Florida rivers and creeks may rise into action or minor flood stage this week.
More information on Tropical Depression Nine, 95L, and 96L can be found at www.nhc.noaa.gov.
Briefing slides are attached. Another update will be issued Tuesday evening.
AM Tropics Update 8-21-12 (1)
http://www.oysterradio.com e-mail manager@oysterradio.com with comments
No comments:
Post a Comment