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Wednesday, July 06, 2005 |
| At 11 PM EDT the center of hurricane Dennis was at 16.5 North 73.4 West, 245 miles east-southeast of Kingston, Jamaica and moving to the west-northwest at 15 mph. Maximum sustained winds are 80 mph and pressure has fallen to 980 millibars(28.94") Dennis has gotten his act together as winds have increased and pressure has fallen steadily. A Central Dense Overcast (CDO) feature is now present. Indications are that a closed eye is starting to form. After the 72 hour period, forecast models have two different ideas on how Dennis is going to move, with the difference being how they develop a ridge of high pressure north of the potential landfall area. Because of the disagreement, the forecast track is mostly an extension of the previous one, albeit shifted slightly right (east). Now that Dennis is well-organized, the only thing that can hamper his development in the near term is land, otherwise he is poised to do nothing but strengthen. Intensity forecast is not as agressive as their models in strengthening Ivan; nonetheless it is 5 knots higher than previous forecasts; bringing Ivan to 105 knots in 36 hours. It is still expected that upper air conditions will be less hospitable for strengthening in the Gulf of Mexico, so no strengthening is forecast between then and landfall. 2005 Hurricane Season, Weather comment []11:10:57 PM  trackback []
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| SHORTLY BEFORE 527 PM
EDT...RECONNAISSANCE AIRCRAFT MEASURED A FLIGHT-LEVEL WIND OF 79 KT IN
THE NORTHEAST QUADRANT ON THEIR OUTBOUND LEG...WHICH EQUATES TO A
SURFACE WIND OF ABOUT 71 KT. A CENTRAL PRESSURE OF 985 MB WAS ALSO
MEASURED. BASED ON THIS INFORMATION...DENNIS IS BEING UPGRADED TO A
HURRICANE
 2005 Hurricane Season, Weather comment []6:21:31 PM trackback []
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| At 5 PM EDT the center of Tropical Storm Dennis was at 16.0 North 72.5 West, 315 miles east-southeast of Kingston, Jamaica. Movement is to the west-northwest at 14 mph. Observed winds and pressure are 65 mph and 987 millibars (29.15"). Jamaica, south-western Haiti, and south-eastern Cuba are now under hurricane warnings. Wind speeds are decreased slightly based on the observations of the hurricane hunter (remember that today's previous advisories were based on satellite estimates). However, pressure has dropped and Dennis is expected to become a hurricane shortly. Intensity forecast is about the same as previous advisories, bringing Dennis to 115 mph winds in 48 hours (and holding him there). Forecast track is shifted to the left slightly, bringing Dennis in the vicinity of Mobile, AL on Monday. Ususal disclaimer about the reliability of models at long time periods. This seems to be a case of winds trailing the pressure falls. I think the hurricane hunter is going to find winds to justify hurricane classification for Dennis before it leaves the area (8 PM) tonight. Dennis' appearance on satellite has improved since the plane first came on station this afternoon. 2005 Hurricane Season, Weather comment []5:12:03 PM trackback []
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| 2:14 PM EDT First substantive observation from the recon is 989 millibars at the surface and surface winds of 58 mph. More to folow. LATER: 3:31 PM EDT - Eye dropsonde finds pressure still 989 millibars. 3: 50 PM EDT - pressure down to 987 millibars. At this latitude that kind of pressure would infer a hurricane, but hitherto the plane has not found the requisite winds... 4:29 PM EDT - Last complete pass still did not find hurricane force winds... looks like next update package will be for a Tropical Storm, still, contrary to my expectations. 2005 Hurricane Season, Weather comment []3:01:50 PM trackback []
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| At 2 PM EDT the center of Tropical Storm Dennis was at 15.7 North 72.0 West, 350 miles east-southeast of Kingston, Jamaica and moving to the west-northwest at 14 mph. Winds are 70 mph and pressure is 991 millibars.
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| ...it seems. At 1 PM EDT the Air Force Reserve WC-130 was about 300 nautical miles away from Dennis, so it appears a bit unlikely that observations from it will make it into the 2 PM Intermediate Advisory. Not completely out of the question, but unlikely. Updates as more info becomes available... 2005 Hurricane Season, Weather comment []1:30:36 PM trackback []
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| At 11 AM EDT the strengthening Tropical Storm Dennis was at 15.4 North 71.5 West, 225 miles south-southeast of Port-Au-Prince, Haiti. Movement is to the west-northwest at 15 mph. Maximum sustained winds are estimated to be 70 miles per hour and pressure is estimated to be 991 millibars. Tropical Storm Dennis Advisory Number Seven
Tropical Analysis and Forecasting Branch estimated winds to be 65 knots
while the Satellite Analaysis Branch estimated 55 knots; the forecaster
split the difference for his estimate. Conditions are very
favorable for development. Intensity forecast is near model guidance in
bringing Dennis to the strength of a major hurricane in 48 hours
(forecast holds strength there until landfall). Forecast track is relatively unchanged (brings Cindy to Pensacola Saturday night/Sunday Morning) and is close to the model consensus. A hurricane hunter was scheduled to launch at 11:15 AM and scheduled to be on station at 1 PM. There is no doubt in my mind that they will find a hurricane when they get there; expect it to be declared so at the 2 PM advisory. The intensity forecast seems to be based on an expectation that upper level winds will be unfavorable for further development of the hurricane once it reaches the Gulf of Mexico. At this time that appears to be reasonable. I would set my unofficial watch area from New Orleans to Tampa. People in those areas should be paying close attention to Dennis and be mindful of the potential of the storm heading their way. My unofficial warning area is from Mobile to Wakulla. Residents living between those two points should begin making basic preparations for a major hurricane to be in their area by Monday morning. The current model trend indicates that those points are more likely to shift eastward then west, but as always, that is subject to change, sometimes rapidly. To summarize the models from overnight: The European was the slowest and furthest to the left bringing Dennis to Louisana in just over six days. The GFS had a similar location but was about a day and a half faster. NOGAPS and the Canadian both had the storm in the AL/FL area, although, as has been the norm with this storm, the Canadian was the quickest to bring the storm to land (on Saturday). UKMET was the furthest east, bringing the hurricane to the Fort Walton area on Sunday night. As one may discern from my unofficial watch/warning areas, my thinking favors the models on the right (eastern side) of the envelope. More later as data comes in from the hurricane hunter. 2005 Hurricane Season, Weather comment []11:40:12 AM trackback []
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| At 10 AM CDT the center of weakening Tropical Depression Cindy was at 31.4 N 88.4 West, 50 miles north-northwest of Mobile, Alabama. Winds are down to 35 mph and pressure is 999 millibars (29.50") 2005 Hurricane Season, Weather comment []10:43:20 AM trackback []
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| From the NHC DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT AND DOPPLER 2005 Hurricane Season, Weather comment []12:00:45 AM trackback []
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© Copyright
2005
Charles Fenwick
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Last update: 8/2/2005; 2:00:33 PM .
Last update: 8/2/2005; 2:00:33 PM .
