I have my B.S. in atmospheric science from Florida International University and am currently in graduate school conducting hurricane research.
By: SouthDadeFish , 3:49 PM GMT on July 25, 2011
As of this morning, the only player out in the Atlantic today is recently deactivated invest 90L, located between Jamaica and Southeastern Cuba. Although the invest has been deactivated that doesn’t mean it can’t get better organized and become reactivated. To be honest, I’m surprised the invest wasn’t deactivated earlier as it was pretty ragged the past two days.
However, this morning the tropical wave (who I will still call 90L for clarity), has began to fire deep convection. There does appear to be a modest amount of cyclonic turning on satellite imagery, although not nearly as strong on radar.
It appears that 90L is finally starting to generate convergence on its eastern side. I’m wondering if this is due to land interaction with Jamaica, which is piling up air due to stronger friction than the sea surface. The air to the north is then moving faster relative to the air over Jamaica, which would in turn create a circulation effect. We will have to monitor how the 850mb vorticity changes throughout the day to check for development.
In terms of upper-level winds, wind shear is a moderate 10-20 knots over the wave. This is marginally conducive for cyclogenesis. 90L is also moving into a moister environment, which will further aid in development. The NW Caribbean is notorious for breeding tropical cyclones as well as intensifying them quickly. Although 90L is pretty disorganized, I’m still giving it a 15-20% chance of becoming a tropical cyclone sometime during its lifetime due to the factors listed above. Once 90L slides farther away from Cuba, it will have its best chance thus far at developing into a tropical cyclone.
The 6Z GFS 72 hour upper-level forecast shows very light winds over the Gulf of Mexico, which would be favorable for intensification if 90L were to develop. Regardless of development the wave will continue to slide west into the Gulf of Mexico and probably then into Southern Texas, who I’m sure wouldn’t mind getting some more rain and relief from the heat.
Figure 1.1: 7/25/11 6Z GFS 72 hour 200mb forecast. This what the model is forecasting the upper-levels of the atmosphere to look like in 72 hours. Notice the winds barbs in the Gulf of Mexico showing very light winds, which would mean very light wind shear.
Although invest 90L has been deactivated and the NHC is giving it a near 0% chance for development in the next 48 hours, I would recommend you still keep an eye on it if you live in the NW Caribbean or Western Gulf Coast areas.
Feel free to check out www.Canefever.com for great links and analysis to track 90L and the rest of the tropics.
Thanks for reading,
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