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So long Irene, hello TD 10

By: Dr. Jeff Masters, 4:35 PM GMT on August 13, 2005

The Hurricane Hunters just paid a visit to Irene, and found a substantially weaker tropical storm. The central pressure was just 1000 mb, and maximum flight-level winds were 40 mph on the west side of the storm. Satellite imagery shows a decrease in deep convection and warming of the cloud tops.

Last night's mission by NOAA's G-IV aircraft gathered a large high-resolution set of data surrounding Irene, and this data was used to initialize this morning's models. These models continue to show that Irene will turn to the north and northeast, missing the U.S. coast by a wide margin. This is a high-confidence forecast, due to the excellent data used to initialize the models and the continuity of the model forecasts from yesterday to today.

TD 10
An impressive low pressure area in the mid-Atlantic near 12N 44W appears to be developing into a tropical depression. Deep convection near the center has increased markedly in the past few hours, spiral banding has increased, and upper-level outflow has improved. Quikscat satellite winds show a circulation center near 12N 44W as of 10:43am EDT, with the strongest winds not contaminated by rain at 20 kt. Rain-contaminated winds as high as 35 kt exist north of the center, suggesting that the low may indeed be a tropical depression. NHC will probably start issuing advisories on TD 10 at 5pm EDT today.

The storm will continue to move to the northwest or west-northwest over the next few days, not posing a threat to any islands until perhaps Wednesday. The GFS model moves the storm northwest, bypassing the Caribbean islands, then tracks it on a more westerly course towards the U.S. late next week. The storm is headed into an area of very dry air to its northwest, which may inhibit its growth and intensification. However, water temperatures are warm (28 - 30C) ahead of it and vertical wind shear is light, so it is likely that it will attain at least tropical storm status. If so, it will be named Jose.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.