Epsilon Keeps Going and Going

Posted on December 6, 2005

The National Hurricane Center (NHC) continues to track Epsilon, the enduring December hurricane that is primarily a threat to ships at this point. Epsilon is the longest lasting December hurricane on record. The NHC forecasters are even starting to show some humor about Epsilon in their forecasts.

THE END IS IN SIGHT. IT REALLY REALLY IS. BUT IN THE MEANTIME... EPSILON CONTINUES TO MAINTAIN HURRICANE STATUS. HI-RES DATA FROM THE 2037Z QUIKSCAT PASS SHOWED SOME VERY REASONABLE-LOOKING 60 KT VECTORS IN MUCH OF THE EYEWALL...AND ALLOWING FOR THE HORIZONTAL RESOLUTION OF THE INSTRUMENT...IT IS LIKELY THAT THERE ARE STILL SOME 65 KT WINDS PRESENT IN THE CIRCULATION. DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB ARE ALSO STILL 65 KT. WATER VAPOR IMAGERY...HOWEVER...SHOWS NORTHWESTERLY FLOW BEGINNING TO IMPINGE ON AND DISRUPT THE OUTFLOW TO THE NORTH OF THE CYCLONE.

Dr. Jeff Masters has posted about Epsilon's unusual ability to survive in adverse conditions and perplex forecasters.

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!

Hopefully we can learn something from Epsilon. Wilma also it seems intensified more than was expected -- although Wilma's intensification was not nearly as surprising as Epsilon's continued ability to outlast expectations.

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