The National Hurricane Center in Miami just issued Tropical Discussion #2 on Tropical Storm Erika and its pretty much a repeat of the first discussion.  But what was really of interest to me is the official NHC forecast verses the HWRF and the GFDL model forecast (which have been fairly accurate so far this season).

The storm is expected to strengthen over the next few days, but most of the global models at that time are showing strong upper-level westerlies over Erika, which would weaken the storm significantly.  However, the two models that have been most impressive thus far this season (in my opinion) are both forecasting Erikia to become a major hurricane instead.

Here is the interesting point from discussion #2:

ERIKA COULD STRENGTHEN SOME DURING THE NEXT DAY OR TWO.
THEREAFTER...MOST OF THE GLOBAL MODELS HAVE STRONG
UPPER-LEVEL WESTERLY WINDS OVER ERIKA...A PATTERN THAT
IS NOT FAVORABLE FOR STRENGTHENING. IN FACT...THE OFFICIAL
FORECAST CALLS FOR WEAKENING DURING THAT PERIOD AS
OPPOSED TO THE GFDL AND HWRF THAT BOTH MAKE ERIKA
A STRONG HURRICANE.

The NHC has taken sides with the “other” forecast models and believes that after a few days of strengthening that the westerlies over Erika will in fact weaken the storm and prevent major hurricane status – it’s a showdown between human analysis and computer forecast modeling in the tropics!

Erika is currently nearly stationary at 17N 57W and has sustained winds near 60mph.  Over the past few hours  satellite has shown an impressive display of deep convection in the storm system.

It will be interesting to see if NHC’s forecast can validate.  I love a good showdown of man vs. machine!

Tags: tropical season 2009