This year, after being increasingly frustrated with poor or inaccessible records of past hurricanes (in basins other than the Atlantic and East Pacific, anyway), I started keeping my own records. And so I have noted every Joint Typhoon Warning Center advisory this year (er, almost). And in the process, I’ve noticed something interesting that I’d like to comment further upon, in the hope that some experts may drop in and share their thoughts.
With both Cyclones Indlala and Kara of this month, the same thing happened. In between official advisories, the storms substantially intensified and then weakened again. Thus, with Indlala, the JTWC reported on March 14 that the storm was at 115 knots in advisory 6, and then that it was at 105 knots in advisory 7. But note that in between, the storm went up to 125 knots before going back down again.
Something similar happened with Cyclone Kara (pictured above). In between JTWC advisories 4 and 5 on March 26, the storm apparently revved all the way up to 105 knots, or Category 3 strength, before declining back down to 75 knots by the time of the official advisory. Or as JTWC put it at the bottom of the advisory (but not in the section where the storm’s official intensity is given):
PEAK INTENSITY OF 105 KNOTS OCCURRED NEAR 26/06Z WHEN SYSTEM HAD A PINPOINT EYE AND HAS DECREASED SINCE THAT TIME.
So my question: Is this kind of between-advisory behavior included in the official “best track” records? And if not, could that lead to a bias in studies of hurricane intensity?
The problem seems to have infected at least one archive. Unisys Weather, which I’ve often found to provide a pretty good record, only lists Kara as a Category 1 storm….