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By: Dr. Jeff Masters, 1:02 PM GMT on April 14, 2006

Well, we need to re-write the record books--again--for the amazing Hurricane Season of 2005. The season added another named storm to its near-unassailable record for number of named storms, which now stands at 28. NHC announced this week that previously unrecognized subtropical storm formed over the Atlantic near the Azores Islands on October 4, 2005. In the National Hurricane Center's report on the unnamed storm, the authors comment that on rare occasions, routine post-season review reveals the existence of tropical or subtropical storms that should have been given a name. The last time this happened was for 1997's first storm. In the case of the unnamed 2005 storm (which I'll call Should-have-been-Tammy, since that was the next name on the list when it formed), the storm started off as a non-tropical low pressure system. However, on October 4, microwave satellite data from the AMSU instrument on NOAA's polar-orbiting satellite revealed the presence of a warm core in the storm . Additionally, when Should-have-been-Tammy passed through the Azores Islands on Ocotber 5, no change of temperature was noted, as would have been the case if this storm was extratropical in nature. Extratropical storms derive their energy from temperature differences within them, and one should always see some sort of frontal passage and temperature change when these non-tropical storm pass by. Should-have-been-Tammy was not fully tropical, though, since its warm core did not extend all the way to the top of the lower atmosphere, and there was no upper-level anticyclone on top of the system. Thus, Should-have-been-Tammy will forever be called "Unnamed subtropical storm 4-5 October 2005."

Figure 1. METEOSAT-8 visible image of Should-have-been-Tammy taken at 15 UTC October 4, 2005. Surface observations are overlaid on the satellite image, and a cold front is analyzed to the west.

The existence of Should-have-been-Tammy raises an interesting point--if the storm had been correctly identified at the time and given a name, Hurricane Wilma would have been given the name Hurricane Alpha. This would have raised the question of what to do about replacing the name Alpha in the list of Greek names, since Alpha would have had to be retired. I've heard rumor that the list of Greek names is going to be ditched in favor of an alternate naming system, but I haven't heard anything official on this yet.

Severe weather outbreak today and Saturday
After a one-week break, severe weather returned to the central U.S. again last night, when tornadoes struck Iowa, killing one, and causing extensive damage to the University of Iowa campus. The Storm Prediction Center has put Indiana, Ohio, Illinois, and Iowa in its "Moderate Risk" bullseye for today, and western Iowa and eastern Nebraska on Saturday.

Next week: I'll comment on the Wall Street Journal opinion piece by noted MIT atmospheric scientist Dr. Richard Lindzen accusing climate scientists of alarmism intended to generate research funding.

Jeff Masters
A Hail of a Night
A Hail of a Night
This came crashing through the skylight in our kitchen. It broke when it hit the floor. It was bigger than a golf ball.

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.