1960-1961

[quandary]

4 Category 5 Hurricanes formed in this two year period:

Donna, Ethel, Hattie and Carla. Of these, only Carla was a high end Cat 5, with winds of 175mph and a pressure of 934mb. Carla was also reputed to be one of the largest storms on record. Somehow, I strongly doubt this pressure windspeed correlation. However, it is likely that Carla was a Cat 5 at some point in her lifecycle.

Donna was probably a Cat 5 too, considering that it was a Cat 4 for so long. Its pressure as a Cat 5 was also in the 930s and it was a large storm. However, the pressure appeared to drop thereafter as it reputatedly weakened to a Cat 4. Questionably a Cat 5.

Ethel was the storm that no one really believes was a Cat 5. Minimum pressure 981mb and it also weakened 4 categories in a single advisory. No storm surge was recorded to match a Cat 5.

Hattie had the lowest pressure. It was probably a Cat 5 or near it with a pressure of 920mb.

[Dr. Jonah Rainwater]

4 Category 5 Hurricanes have also formed in the 2004-2005 two year period.

I see the point you're making, but I don't think the Hurricane Hunters had equipment in 1961 that was anywhere near as advanced as what we have in 2005. Today we practically carpetbomb the eye with dropsondes to pinpoint the exact location of the lowest pressure at the center, so it's natural that we're able to record lower pressures. Like if we had a Hurricane Hunters fleet that was capable of spending longer periods of time inside a hurricane, or simply more planes and more fuel, then the Hunters probably would have found an even lower pressure and probably higher windspeeds inside of Wilma. So in the future, with more advanced equipment, we might find a storm exactly like Wilma to have an even lower pressure... (the W-Pac would also benefit from more accurate observations, of course...)

So, I think it's possible that Carla, Donna, and Hattie had much lower pressures than were actually recorded. Ethel was probably a microburst inside the eye of a strengthening Cat2 that had no business attempting to strengthen, and collapsed on top of itself.

If you look at three year periods, 2003-2004-2005 holds the record, with Isabel, Ivan, Katrina, Rita, and Wilma. (all with I in the name...wierd) And then with four year perioods, 1958-1961 still holds it because of Cat5 Cleo in 58.

If there is a Cat5 hurricane next year, we'll have beaten one of the most impressive records from the last 30-year active cycle.

[f5]

If Carla was bigger than Katrina than why was Katrina a CAT 3 at 927 mb and Carla a CAT 5 at 931 if Carla was bigger?

[quandary]

If there is a Cat5 hurricane next year, we'll have beaten one of the most impressive records from the last 30-year active cycle.

Yeah what I was trying to get at (before I got a bit distracted) was that it should be declared that we have beaten the record because the previous record is composed of shoddy Cat 5s while ours are clearly bonafide Cat 5s. Isabel, Ivan, Katrina, Rita and Wilma rank in as the number 1, 4, 6, 9 and 11th strongest storms of all time. Actually, when they made their ranks, they were the 7th, 6th, 4th, 3rd and strongest storms.

Also, it seems too unlikely that there was a sub-900mb spot in Carla, since that's what would've been needed to support a cat 5 with Carla's wind spread. Any professionals want to comment?

[stormcloud]

If Carla was bigger than Katrina than why was Katrina a CAT 3 at 927 mb and Carla a CAT 5 at 931 if Carla was bigger?

Ah, the Pandora's Box of pressure vs. wind debate. Ask Bastardi about that one (or even Neil Frank....)

[Scorpion]

Carla was likely not a Cat 5 or had a much lower pressure.

[Dr. Jonah Rainwater]

Carla was likely not a Cat 5 or had a much lower pressure.

I'd say it just had an unrecorded lower pressure - the windspeed measurement is probably accurate.