Irene Update

Tropical Storm Irene is nearing Hurricane strength as she bears down on Puerto Rico.  Here is the latest Infrared  Rainbow Satellite Image.

Tropical Storm Irene- winds at 70 mph

Winds are up to 70 MPH and pressure has dropped to 989 mb.  This already makes Irene as the strongest storm of this season thus far.  Irene will break this shortly.  Puerto Rico is certainly in for a rough night.   Winds will gust to 80 mph and flash flooding is likely as 5-10 inches of rain will fall on the island.  I had hoped to get a radar image of the Hurricane on the blog, but the images are currently down.  This confirms how strong Irene has already gotten.  With pressure down to 989 I expect Irene to be a Hurricane by 2 AM.

My track forecast for Irene

National Hurricane Center forecast 

I believe the National Hurricane Center is keeping the track too far to the west.  They note in their 11 pm discussion that they are uncertain of what effects the mountainous terrain of Hispaniola will have on the system.  I believe the storm is hardly effected by these and will strengthen, turning north more quickly.  Also, Jacksonville, FL is hardly ever hit by tropical systems.  Hurricane Cleo (1964) hugged the Florida coast and is noted by some forecasters as a possible parallel.  However Hurricane Dora (also 1964) is the only Hurricane since 1851 to directly hit Jacksonville.  So I am doubting the NHC forecast.  Model consensus has pushed further east, over the gulf stream.  This is a potential alarming trend, due to how warm the waters of the Gulf Stream are.  Its not just how warm the GS is either- a Hurricane will intensify when it moves over pools of warm water due to fluctuations in how quickly new thunderstorms are forced upward in the core (lapse rates).   For example, water that is 82 degrees over a large area will keep a Hurricane going with moderate strengthening if all other conditions are equal.  But if there is a patch of 83 or 84 degree water in its path, the storm is more likely to rapidly intensify. 

I've gone stronger than the Hurricane Center on intensity, but not as aggressive as some of the weather models.  The timing is questionable.  I will refine that tomorrow after reviewing tonight and the morning model runs.  At this point, I think New England will see some sort of enhanced rainfall from this system next weekend.  While looking at my 6 day track you can probably guess where I'm leaning with it, I'm not ready to sound any sort of hype alarm until the storm starts to make its turn north.  Warm Atlantic Ocean, second year of a La Nina is a classic East coast Hurricane signature, specifically North Carolina.  Out of all the areas this is where I am most concerned for.  The latest American long range model is out its "initial condition" already is too far south for where the storm currently is.  Get your popcorn ready weather fans!