Very Active Tropics Continues Next Week

Written by ICECAP

Sep 01, 2008
By Joseph D'Aleo, CCM, AMS Fellow

Gustav is weakening inland and Hurricane Hanna is vacationing in the Bahamas. Tropical Storm Ike is organizing in the eastern Atlantic (off the image).

The hurricane season was expected to be active with enhanced landfall threats. This is characteristic of summers when the Atlantic is in its warm mode and coming off La Nina winters. Not surprisingly though the media including AP's Seth Borenstein blamed this year's storms and the increase in activity since 1995 on global warming. He quoted his favorite AGW cheerleaders Judith Curry and Kevin Trenberth who provided statistics to support the increase in activity since the 1990s.

No one questions that increase. Bill Gray and vurtually all real hurricane forecasters and experts predicted the Atlantic would see an increase in the number of storms, major storms and landfalling systems ever since 1995 based on natural multidecadal cycles in the Atlantic.

The Atlantic goes through cycles of warming and cooling with a period of about 70 years. A measure of this is the AMO, the standardized North Atlantic mean temperature from 0 to 70N. Note the warm period in the late 1800s, the late 1920s to the middle 1960s and again after 1995.  Curry and Trenberth want you to believe the natural cold to warm transition of the AMO during thw middle 1990s is somehow driven by CO2.  See the recent flurry of peer review science that refutes any unnatural tropical variability here.

See larger image here

Then number of storms and the number of major hurricanes (CAT 3-5) increase during the warm Atlantic phases as shown below.

See larger image here

So far this year the Gulf and Florida has borne the brunt but before the week is over the southeast will see Hanna make landfall and its heavy rains and gusty winds are felt in the Mid-Atlantic and northeast. It doesn't appear Hanna will be able to intensify much with strong northerly shear and is forecast to come inland as a CAT 1 system. It has defied the shear to become a hurricane however.

Storms that hit the northeast directly often come from near where Hanna is but it appears too much ridging to the north will develop the next few days and deflect it northwest before it turns up the coast. The season is not over after this week, only time will tell whether because La Nina has weakened, only Hanna will affect the east coast or whether more like Ike will follow. The Gulf is not out of the woods for another threat from Ike next week. See much more here.

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