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Epsilon refuses to obey the rules

By: Dr. Jeff Masters, 7:45 PM GMT on December 04, 2005

Epsilon refuses to obey the rules. Not only has Epsilon refused to die as expected--it has strengthened in the past day to near Category 2 strength. Epsilon is traversing 22-23C waters, which are a full four degrees C (7 F) below what is normally thought of as the minimum needed to allow a hurricane to strengthen. The upper level winds are unfavorable--Epsilon was been under 20 knots of shear the past two days. It is unusual to see a hurricane intensify in the face of 20 knots of shear (although Wilma managed to do so). It is unheard of for a hurricane to intensify in the face of 20 knots of shear, and with 22C water temperatures under it. Like I've been saying about this entire Hurricane Season of 2005, the normal rules do not apply. Epsilon is another storm that we do not understand, and I hope someone out there in grad school is taking data on this storm and writing a Ph.D. thesis on it!

Epsilon will continue to hang around most of the week. A strong ridge of high pressure has built over it, forcing it on a eastward track that will keep it from passing over really cold 20C waters to the northeast that would have surely killed it. By Wednesday, this ridge of high pressure is expected to force Epsilon southward and then southwestward towards warmer waters. However, by this point, the shear over Epsilon should be somewhere near 40 knots, which should be able to rip the storm apart. This should put a end once and for all to the Hurricane Season of 2005. I don't expect anything else to develop this month, since forecast wind shear levels over the Caribbean Sea the next ten days are now looking only marginally favorable for tropical storm formation.

Jeff Masters

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