Masters student in tropical meteorology at FSU. Raised in Alaskan blizzards, but drawn toward tropical cyclones by their superior PGF.
By: Levi32 , 4:23 PM GMT on June 14, 2009
Tropical Tidbit from 12:30pm EDT Sunday, June 14, 2009:
The weather pattern over the Caribbean is finally starting to change this morning. The upper trough has moved out and the cut-off upper low that used to be its tail is backing SW near Belize. This has allowed the sub-equatorial ridge to start expanding northward over the west-central Caribbean, which is lowering wind shear values over the persistent surface trough in the area. This trough is not expected to significantly develop and will drift northwestward towards the Yucatan over the next 3 days, bringing rain to Jamaica, Honduras, Nicaragua, and western Cuba, enhanced by the divergent flow on the east side of the retreating upper low.
The models are forecasting a low to develop in 3 days near North Carolina along a quasi-stationary front draped across the NW Atlantic. The GFS quickly takes this feature out to sea as a cold-core entity, but the CMC, UKMET, and NOGAPS all try to do mischievous stuff with it, trying to trap it under the building ridge to the west and bringing it south towards Florida. This is a possibility that cannot be discounted, but any low that forms will be mostly cold-core in nature and have to convert to sub-tropical, and that takes time. The environment would be marginally favorable with low wind shear in the void between the sub-tropical and polar jetstreams. SSTs in the Gulf Stream off North Carolina are warm enough to support a sub-tropical cyclone or a weak tropical one. Old fronts are one of the primary causes of early-season tropical development, and therefore this area will be monitored over the next 3-5 days.
The worldwide slump in tropical activity continues. Invests 99W and 98W in the west Pacific are still not ready to develop as they are robbing each other of their own energy. The east Pacific still can't organize anything, and the western Caribbean is not in its game yet either. The east Pacific should be the first to get going here soon as the MJO is enhancing lots of convection there. In 10-15 days we need to watch the southern Gulf of Mexico as heat and moisture advect northward under the upper ridge. I believe we have a strong chance of getting a tropical disturbance in that area during that time.
We shall see what happens!
Caribbean Visible Satellite: (click image for loop)
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