WX-MAN's Musings

11a.m. Update: Figures as soon as I finish this post TD #10 becomes Josephine, the tenth names storm of the 2008 Atlantic Hurricane Season… It appears that Josephine could be a Hurricane very soon per the NHC discussion:

JOSEPHINE IS CURRENTLY OVER SEA-SURFACE TEMPERATURES OF ABOUT 28 CELSIUS…AND THE WATERS ALONG THE FORECAST TRACK WILL REMAIN AT LEAST THAT WARM FOR ABOUT THE NEXT 24 HOURS. WIND SHEAR IS ESSENTIALLY NON-EXISTENT OVER THE CYCLONE…SO STEADY STRENGTHENING SEEMS LIKELY IN THE SHORT TERM…AND COULD BE RAPID GIVEN THE INCREASED ORGANIZATION AND THAT THE SHIPS-BASED RI INDEX GIVES A 50% CHANCE OF AN INTENSITY INCREASE OF 30 KT OR MORE IN THE NEXT 24 HOURS

Because I am at work I don’t have much time to do a full post but I wanted to share a few changes in the tropics this morning and share some information I have read…

First the updates on the tropics. When I went to bed last night Gustav was a hurricane but was expected to weaken since it was well inland, Hanna had been upgraded to a hurricane, Ike was named a tropical storm and there was a wave of interest coming off the African coast. Now as of Tuesday morning, Gustav is a tropical depression, Hanna was downgraded back to a tropical storm, Ike still remains a tropical storm and that wave off of Africa is tropical depression 10 or soon-to-be Josephine.

The only storm of any immediate concern has to be Hanna, and it is taking a “serious beating” from two sources. One being strong upper level winds that are shearing away at Hanna’s structure and circulation (Which you can see from the visible satellite image from 10:30 a.m. EDT) and the other is the island of Hispaniola. Depending on how long this takes place and how much farther south the upper level winds push Hanna over Haiti, as Brendan Loy, the Pajamas Media “Weather Nerd,” points out, “this is a wait-and-see situation for sure. Haiti may be the death of Hanna.”

11 a.m. update: Brendan may be right about the “death of Hanna” but I think it is a combination of shear and land. It appears the NHC is trying to throw a little dirt on the possibility of Hanna being a strong hurricane:

HANNA HAS FINALLY SUCCUMBED TO THE STRONG VERTICAL SHEAR WITH VISIBLE SATELLITE IMAGERY SHOWING A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION AND A SHRINKING CDO FEATURE. THE INITIAL INTENSITY IS SET AT 60 KT…BUT GIVEN THE CURRENT SATELLITE PRESENTATION…THIS MIGHT BE A BIT GENEROUS. AN AIR FORCE RECONNAISSANCE AIRCRAFT WILL INVESTIGATE HANNA THIS AFTERNOON AND PROVIDE A BETTER INTENSITY ESTIMATE. WATER VAPOR IMAGERY SHOWS A SHARP EDGE OR DEFORMATION AXIS ON THE NORTH SIDE OF THE CIRRUS CANOPY SUGGESTING THAT THE SHEAR WILL PERSIST IN THE SHORT-TERM…AND SOME ADDITIONAL WEAKENING IS POSSIBLE TODAY AND TONIGHT. IN ABOUT 24 HOURS…GLOBAL MODELS SHOW THE SHEAR WEAKENING AND THIS COULD ALLOW HANNA TO RESTRENGTHEN. HOWEVER…GIVEN THE PRESENT LACK OF ORGANIZATION…IT IS DIFFICULT TO KNOW HOW MUCH STRENGTHENING IS POSSIBLE. THE NEW OFFICIAL FORECAST IS LOWER THAN THE PREVIOUS ADVISORY BUT SHOWS HANNA BECOMING A CATEGORY ONE HURRICANE IN ABOUT 36 HOURS. IT SHOULD BE NOTED THAT THIS IS A LOW CONFIDENCE FORECAST. IN FACT…IF ONE CONSULTS THE WIND SPEED PROBABILITY PRODUCT INCLUDED IN THIS PACKAGE…IT CAN BE SEEN THAT THERE IS NEARLY AN EQUAL PROBABILITY OF HANNA BEING A TROPICAL STORM OR HURRICANE AT DAY 3.

Of course there are other forecasters out there that think Hanna will bounce back like Rocky…

Hanna is going to take a beating today and tonight as the core of a 60 kt jet comes right into the storm. The reverses quickly tomorrow though, and like Rocky against Drago ( Mr. T, Appollo Creed, Mason Dixon or whoever shows up in his movies) Hanna should be standing tomorrow with nothing in her way but warm water and improving outflow. The call for the major hit between Hilton head and Wilmington for Friday holds from this forecaster. The TPC discussion is saying as much without saying it, acknowledging the ideal outflow situation that develops and the chance this a major hurricane at landfall. So I think now we are on the same page. I strongly advise the reading of all TPC discussions so you have all information at hands, as well as anyone else you have found a reputable source of info.

Even Alan Sullivan is taking a wait and see type of aptitude with Hanna and may have to re-evaluate the original thought process by many of us yesterday:

Hanna is hitting NW Haiti. This was not modelled. Flooding rains and much loss of life could occur. Southward motion continues, according to the satellite imagery, or else the storm is becoming vertically displaced. I have not checked for surface circulation center on closeup visible image. The upper flow is too strong. We will have to totally rethink Hanna’s future. Weakening has aready commenced. (as of 8 a.m. EDT) Pressure 987 mb. Winds 70 mph.

As of the 8 a.m. update by the NHC, Hanna was still forecasted to make landfall, as a hurricane, in the Carolinas sometime either Friday and Saturday. I agree with Alan that depending on how Hanna comes out of this “beating” it is taking on this forecast may change completely.

Because Hanna is expected to impact the southeastern United States, and at this point, South Carolina specifically, I have a few more weather blogs I would like to share. One is Jared Smith who has Charleston Weather Blog, you can also follow him on Twitter. (Note: You can also follow me on Twitter or Plurk)  Then there is Brian Goode, former South Carolina meteorologist who still blogs on the region and its weather.

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