Monday, August 1, 2011

T.S. Emily

Lessons learned:

Emily was a struggle to forecast from the very beginning. Last weekend conditions were so favorable for it to develop, that NHC gave it a 100% chance of becoming a depression. It never did.  Recon planes went out and could not find a center of circulation. Then ,when it appeared atmospheric conditions were becoming more hostile, it defied the odds and became a Storm.

It slowly made its way west from the Atlantic, over the Lesser Antilles, and into the Caribbean Sea dumping plenty of rain along its route.

Emily showed plenty of promise that it could grow stronger, and little by little the winds inched up until they capped off at 50 mph, then something happened. In spite of plenty of available heat energy from the ocean, little shear, and favorable upper atmospheric conditions, it never grew stronger. Hurricane hunters made repeated trips to find the center but it was very illusive. This became a major headache for forecasters at NHC because without a good fix on the center, all the models would have a hard time determining a future path. This was reflected in the cone shifting various times. 

Emily eventually came to a stop on Wednesday, and fears grew that it may finally be getting stronger, but recon again failed to find a defined center. The system however was loaded with  moisture and the skies opened up with plenty of rain across Puerto Rico, Dominican Republic, and Haiti.Some areas could end up with 6-10" of rain, some pockets as much as 20".

In the office, we saw most models kept taking Emily over Hispaniola. Some of the highest terrain in the entire Caribbean is found here. We wondered if Emily would survive a direct impact. Some models dissipated the system altogether, while others kept it alive and intensified it down the road. South Florida was kept in the cone in case Emily decided to throw us a curve ball, but fortunately, it struck out. With strong upper level winds ahead of it, dry air injected on its western edge, and a poor organized center, it finally came to an end Thursday afternoon.

There is still some moisture lingering over the area that will devastate parts of Hispaniola, and could in the long run, cause some rain for us over the weekend.

All in all, the staff learned, that even though conditions may say they are 100% right for a system to develop, it may not happen. We also learned that while many models predicted Emily getting stronger and only a few killed the system outright, we should never underestimate the lone model.
This is what NHC said regarding the lone model on Thursday:

THIS WAS A BIG WIN FOR THE ECMWF GLOBAL MODEL...WHICH NEVER DEVELOPED EMILY AND ALWAYS FORECAST DISSIPATION NEAR HISPANIOLA.


We are proud  however, that we showed the high peaks of Haiti and Dominican Republic and how they would weaken this system. We showed a wide variety of scenarios focusing from total dissipation to a possible strike over Florida.  Its never easy forecasting tropical activity, but I am blessed to have one of the best meteorological teams anywhere. I thank them for their input, knowledge, and creativity during this tropical season.


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