Forecast Discussion 9/23

Abbreviated discussion today due to time constraints and lack of activity in the Atlantic.  Ex-Fred is finally gone for good after making "landfall" overnight.  Ex-98L has continued to slowly move northwest, and has become less elongated, however this is likely due to the lack of convective activity on the southeast end of 98L resulting in a decrease of vorticity at that location, and is not a sign of organization of the system.  Thunderstorms are occuring in 2 other locations today, in the southwest Carribean and along the baroclinic zone 15 degrees east of Ft Lauderdale.  The Southwestern Carribean vorticity center is over land, and is not likely to develop into a tropical cyclone for this reason.  A lot of upper level difluence is supporting the convection here, but again, no TC development is expected.  All models, even the CMC to some extent are now killing ex-98L.  (Though this didn't prevent Fred from being a topic of discussion for a good week after all the models began to "kill" it)  However, some models (CMC mostly, but other models show a trough in this location) now develop a cyclone where convection is occuring on the end of the baroclinic zone within a few days, but it does not appear to be completely tropical in nature or very intense. 

In the Pacific, Nora has formed and is moving west-northwest.  It is located around 117W, 16 N.  Model tracks show a lot of disagreement, but a consensus forecast would be a continued path to the west-northwest over the next day or so.  This track will keep the storm farther south than was expected yesterday, which should keep it over warmer SST for a longer period of time.  However, it is still moving into a sheared environment, which should prevent it from strengthening beyond a 24-36 hour timeframe.  It is not expected to strengthen into a hurricane at this time.  By 12Z tomorrow, the forecast calls for Nora to be at 119W, 17N and at 00Z: 121W, 18N.  At this time, it appears that Nora will continue to be the only target of interest.