Mitch, Gilbert, Allen

[EDR1222]

Which one takes the prize as the strongest of these Category 5 Carribean Monsters. I know Gilbert has the lowest pressure on his side, but I read where Allens sustained winds were actually 190 mph. Of course, that data may not have been as reliable back in 1980. Gilbert sure looked like it was about as perfect as a hurricane could look on satellite when he was at his strongest.

Any thoughts?

[SouthernWx]

The flight level wind data on Allen is accurate...they measured flight level winds of 183 kt (210 mph) with the central pressure at 899 mb. Reduced the standard 10% from 10,000' flight level gives an estimated sustained surface wind of 165 kt (or 190 mph).

While Gilbert had a lower central pressure at it's peak (888 mb), the flight level winds were never over 200 mph....peak flight level wind measured 173 kt (199 mph). In all honesty, NHC was generous in estimating max sustained winds at 160 kts....IMO it was more like 150-155 kt (175 mph or so).

The reason Gilbert had sustained winds lower than you'd think at such extreme intensity? BECAUSE hurricane Gilbert was a very large hurricane....the pressure gradient wasn't as tight as occurred in Allen near the Yucatan Channel.

In all honesty, if you use maximum sustained winds to estimate a hurricane's true power....there are some small, tightly knit hurricanes which probably had sustained winds as strong as Gilbert. In fact, as hurricane Andrew approached the Bahamas on August 23, 1992...the flight level wind speeds of 170 kt were nearly as stronge than anything measured during hurricane Gilbert, and IMO surface winds just as intense. 170 kt at 10,000' flight level gives an estimated sustained surface wind of 153 kt (or 175 mph).

Hurricane Mitch IMO was very similar to hurricane Camille intensity-wise...max sustained surface winds in the 155-160 kt range (180-185 mph).

My candidate for the most intense Atlantic hurricane of record (in terms of sustained wind) is the infamous September 1935 "Labor Day hurricane" as it crossed the Florida Straits and middle Florida Keys. This was truly a micro-monster....about the same size of 2004's hurricane Charley....an eyewall less than 20 miles in diameter. Using Charley's observed max flight level winds of 148 kt (170 mph)....along with WSR-88 Nexrad velocity data from WFO Tampa, you have an estimated sustained surface wind of 133 kt (153 mph) at a central pressure of 941 mb.

Using extrapolation from 941 mb to 892 mb...the observed minimum central pressure of the Labor Day hurricane at landfall, the estimated sustained wind value is 173 kts (199 mph)....sustained winds close to 200 mph; with peak gusts likely in the 225-235 mph range; or the same wind velocity of a violent F4 tornado.

In fact, the effects on victoms of the Labor Day hurricane from reports at the time and post hurricane surveys sounds similar to the aftermath of a 15 mile wide violent killer tornado as it passed over Long and Lower Matecumbe Key; many reports of human bodies being decapitated and/ or missing limbs; even a few gruesome reports of bodies found literally "sandblasted" to death...all skin and clothing gone; only skeletons wearing leather belts and shoes

PW

[AussieMark]

Gilbert gets my vote.

888 mb is the lowest central pressure ever recorded in a western hemisphere tropical system.

[HURAKAN]

Gilbert gets my vote.

888 mb is the lowest central pressure ever recorded in a western hemisphere tropical system.

I agree with your decision, but I can't just get rid of the Labor Day Hurricane. Unfortunately, there was no satellite or recon data to support a definite decision toward the Labor Day Hurricane.

[HurricaneBill]

Gilbert gets my vote.

888 mb is the lowest central pressure ever recorded in a western hemisphere tropical system.

Gilbert looked like a super typhoon in the western Pacific.

[Aslkahuna]

Southern makes an important point about storm size. He also notes that the Flight Level winds in Allen were stronger than Gilbert's so by extrapolation the surface winds in Allen should have been stronger.

Steve

[wxman57]

A couple of points. First of all, I believe that Allen was larger in size than Gilbert, so I don't think the wind difference was related to size. But I recall working the forecast desk back in 1988 a few days before Gilbert formed. I was doing a Caribbean surface analysis and a chill went down my spine -- I'd NEVER seen surface pressures so low across the Caribbean! I just had a bad feeling that something big was about to develop. So the reason for Gilbert's lower wind may be a lower environmental pressure, and thus, a lower pressure gradient.

As for converting FL winds to the surface, every single storm is different in that respect. Some storms, like Mitch, have their strongest winds a few hundred meters above the surface, with decreasing winds above that. I saved a few wind profiles from Mitch that show this. So a 140kt storm at flight level could very easily have stronger surface winds than a storm with 160-170 kt at flight level. Can't use FL winds to judge a hurricane's surface winds exactly.

[isobar]

If by "strongest" you mean solely wind velocity, Perry nailed it with Labor Day. Pressure is another issue that doesn't always jive perfectly with wind.

[MGC]

It is interesting to note that the lowest pressure observed of these hurricanes was in the western Carribean. The Labor Day hurricane was not far remove nor was Camille.....MGC

[Derek Ortt]

was Allen flown at 700mb? The reason that I ask this is that often recon flew at 850mb, not 700 during this time period (as was the case with Gloria).

If recon flew Allen at 850mb, then Allens max winds were closer to 145-150KT