20 September 2006

Gordon and Helene both weakening...

Gordon passed over the Azores at 08Z this morning as a 65kt hurricane.  The strongest sustained wind reported at Santa Maria Island was 50kts, the lowest pressure reported was 990mb, and as of 15Z, the intensity was lowered to 50kts and 995mb.  It is holding onto its tropical characteristics, but is expected to gradually transition to extratropical as it passes north of Portugal and toward England over the next couple days.

Helene has weakened a bit to 90kts, and the satellite presentation is less than ideal.  The eye is no longer open, and cloud tops are not as cold as they have been.  The SSTs are ~28C, vertical shear is 10-15kts,  but there is a respectable amount of dry air to the southwest of the storm that could be entraining in.  The latest intensity estimate is 90kts and 958mb, moving NW at 10kts.  A gradual weakening trend is expected as SSTs decrease and shear increases.

The tropical wave I mentioned yesterday just off the African coast continues to get better organized.  Though convection is sparse and scattered, the low-level circulation is improving.  It's presently located at about 9N 29W, or approximately 600km SSW of the Cape Verdes.  This wave was generated over far eastern Africa on Sept 12-13, and has had a history of potent activity as it raced across the continent.  The next number/name on deck is 9/Isaac.

Please visit my tropical Atlantic headquarters.

No comments:

Post a Comment