Wilma's strength still under review, weather experts say

[HurricaneJoe22]

Wilma's strength still under review, weather experts say

By Ken Kaye
Staff Writer
Posted November 20 2005

Some weather experts say Hurricane Wilma might have been a Category 3 system as it barreled over South Florida.

The National Hurricane Center in Miami-Dade County estimated the system was a Category 2. And a National Weather Service preliminary report said most of the region saw Category 1 winds.

Will the real Wilma please stand up?

Though South Florida residents have questioned since the storm's Oct. 24 landfall just how strong it was, the hurricane center still is conducting a review. Official results could be released by the end of this month.

Because the system made initial U.S. landfall near Naples with estimated winds of 125 mph, it likely will be designated a Category 3, or a major hurricane, for the record books.

But experts say Wilma likely will be considered a Category 2 when it arrived in South Florida, based on maximum sustained winds of 103 mph registered at a ground station near Lake Okeechobee. Category 2 winds range from 96 to 110 mph.

Most of South Florida likely experienced Category 1 winds of between 74 to 95 mph, said meteorologist Robert Molleda of the National Weather Service.

"A lot of it is semantics," he said. "When we say highest maximum winds, most people aren't going to see those winds. Those winds will be over a small area."

Meanwhile, he said, even areas that saw Category 1 sustained winds received gusts up to 120 mph.

Some local officials say their jurisdictions were buffeted by winds much greater than those recorded by the weather service. For instance, parts of Broward County felt sustained winds of more than 100 mph, according to emergency managers. In Palm Beach County, the Belle Glade-Pahokee Fire Department said it recorded gusts up to 150 mph.

What nobody disputes is that Wilma left a swath of destruction from the Keys to Martin County, damaging or destroying thousands of homes and toppling trees.

Based largely on information from hurricane hunter aircraft, the hurricane center estimated Wilma had sustained winds of 110 mph while the core was south of Lake Okeechobee.

That was higher than the 103 mph ground reading because aircraft estimates generally are not as accurate as those obtained by anemometers on ground-based towers, officials said. The center said the winds weakened to 105 mph as Wilma emerged over the Atlantic Ocean near West Palm Beach.

Ed Rappaport, deputy director of the hurricane center, said preliminary estimates usually are close to the real thing, but the final numbers also take into account ground observations and Doppler radar readings.

"The reason for the post-storm analysis is to consider any new information that wasn't available at the time," he said.

He noted that in addition to Wilma, the center must re-calculate the maximum winds of more than 40 Atlantic and Pacific storms this year.

Bryan Norcross, director of meteorology for WFOR-Ch. 4, said it is possible Wilma retained Category 3 strength as it reached Lake Okeechobee. That is because sustained winds of 103 mph were recorded for up to 15 minutes just south of the lake.

If those winds are converted into a "one-minute average," which is the amount of time the hurricane center uses to determine a storm's category, the sustained winds could have been as strong as 115 mph, he said.

Otherwise, Norcross said he thinks areas near the core likely saw Category 2 winds of between 100 and 105 mph as the storm struck South Florida.

"If you think about it, a Category 2 storm with 100 mph winds, and has gusts to 120 or 130 mph, that's a powerful hurricane," he said.

Ken Kaye can be reached at kkaye@sun-sentinel.com or 954-385-7911.

[mike815]

I thought so WILMA never lost a beat. i think it wekened little to none over the state.

[MiamiensisWx]

I read the article today. I think Wilma might have been a Category Three when it was just south of Lake Okeechobee and passing near/over South Bay or Belle Glade and possibly a bit beyond that, with the strongest winds in a fairly small area toward the end. I also think it was a moderate to strong Category Two (with 105MPH to 110MPH winds at least) as it moved through the metro areas and exited the coastline.

Any thoughts?

[mike815]

I agree with that. Sounds about right to me.

[MiamiensisWx]

It is possible some areas (including localized areas) saw stronger sustained winds than what most official sources say the area got. For example, some residents in Boca Raton say we got strong sustained winds with gusts to and above 115MPH, or major hurricane status. You also have to take into factor microbursts of stronger winds, including some possible stronger sustained winds. It is also interesting to note that gusts in nearby cities - such as Boynton Beach - were shown in newspapers (Boynton Beach measured a gust up to around 120MPH, or major hurricane strength), while potential very strong gusts or sustained winds in my area seem rather ignored or very slightly underestimated. We could have had winds (and gusts) as strong as other nearby areas and have even higher winds in local areas (the same goes for local areas in other nearby cities during Wilma). Also, it is interesting that readings from wind anemometers at the Boca Raton Airport, which sustained HUGE amounts of damage, were not told about or released. I think there should be more information and effort to determine wind strength in local areas more. This would help to determine a hurricane's actual strength, effects, and other related things better, and also help to determine whether a hurricane was weaker or stronger than originally presumed.

Any thoughts?

By the way, one person in Boca Raton (referred to by BocaGirl) said he/she recorded at wind gust up to around 140MPH. I would, however, presume it would be closer to 120MPH or 130MPH. However, do not underestimate gusts, either - or microbursts.

[Forecaster Colby]

It's also possible there were embedded tornadoes, we had quite a few here in central FL as she moved ashore.

[MiamiensisWx]

Agreed on the tornadoes as well, Forecaster Colby.

[ericinmia]

Agreed on the tornadoes as well, Forecaster Colby.

Actually the Preliminary NWS report said that no tornado's... stormspotter or radar identified were recorded durring the period of Wilma's landfall.

Do you all have any information as to these??? I would be interested to read it.
-Eric

[Forecaster Colby]

They weren't really in the main mass, but a tornado warning was issued twice for Polk County.

[Aslkahuna]

Overland, it's possible to get gusts to 140 mph with sustained winds of 100 mph which is low end Cat 2. Gusts of 120 mph could be experienced with sustained winds of 90 mph which is Cat 1. This is because as the low level winds slow due to friction we get more turbulent mxing that brings the strong winds aloft to the ground resulting in a gust ratio of 1.4-1.6 over land as opposed to the gust ratio of 1.2-1.25 overwater used by NHC (and computed by JTWC back in the 1970's). Also too, gusts have NOTHING to do with the categorization of storms it's the sustained (one minute average in the US) winds that count and sustained winds only.

Steve

[Recurve]

People seem unable to believe that their backyards can be devastated by winds under 100 mph. I've had an ongoing "discussion" with one person here (upper Keys) who is convinced she went through a Cat 3 hurricane with sustained winds way over 100 mph. My rough guess was that this far from the center, we had 75-90 mph sustained (if that). "I saw trees bending all the way over!" she says. "But we had almost no damage to homes," I said. "There's so many broken trees!" others say. But I observe that other than some missing shingles, I haven't seen destroyed roofs, gas station canopies survived, many signs weren't damaged, and none of our power poles snapped.
Certainly some gusts were strong, maybe 100 mph or more, and it just takes one gust to break up trees and cause structure damage. Also, if you were unlucky enough to have a broken branch blow into your roof or car, it can look pretty bad.

The only thing I'm not sure about is the effect of that huge eye. We were very far from the exact center of wilma, but with such a big eye, we were closer to the eyewall than for a more "normal" cyclone. But even if we experienced the max winds of the eyewall, I still can't believe we had more than a Cat 1 hurricane, in terms of sustained winds, here in Key Largo. And people seem not to expect damage from Cat 1 hurricanes.

[Derek Ortt]

most of SE Fla only received cat 1 conditions, and low end cat 1 at that

the cat 2 winds were very isolated and contained to broward

[Zackiedawg]

I may be wrong...but I think the sustained cat 2 winds were measured both in Broward and also the southern portion of Palm Beach county, from Boca Raton to Boynton Beach...and also along the southern lake Okeechobee towns.

Otherwise, I do believe it would be correct to say that the entire eastern populated portion of south Florida experienced cat 1 or less sustained winds, with a small portion experiencing cat 2 sustained winds. Certainly gusts measured 120mph+ in some areas...but too many people seem to think the gust is the hurricane's strength.

My (unprofessional) anemometer saw sustained cat 2 windstrength for several minutes at a time, numerous times throughout the hurricane...and measured gusts to 112mph before the mount gave up and blew the anemometer down. I'm sure we had gusts over 112mph, as I saw gusts with more strength than those measured ones tear through my back and front yard...with lots more force than we saw during Irene, Frances, Jeanne, or Katrina. Only the most powerful gusts seemed capable of creating the total horizontal white-out conditions, and these did the most prominent structural and tree damage.

I would be willing to bet that much of northern Broward county, Boca Raton, Delray Beach, and Boynton Beach saw cat 2 sustained (at around 100mph), with gusts to 120MPH or so. I would doubt that very many other places in southeast Florida saw anything above cat 1 sustained, with occasional gusts over 100mph.

I have doubts that even the worst parts of Wilma on the southeast coast reached a sustained cat 3 strength...certainly some of the more intense bands on either side of the eyewall delivered gusts at that level...but if sustained winds are measured as a 60-second-constant, I don't think any city saw that.

Either way...I've got plenty of respect for a cat 1 storm...let alone a cat 2. 90-100MPH with gusts to 120-130MPH and the threat of tornadoes and damaging debris sounds pretty bad to me, and I'd prefer to limit my encounters with these storms, at least in my backyard!

[MiamiensisWx]

I may be wrong...but I think the sustained cat 2 winds were measured both in Broward and also the southern portion of Palm Beach county, from Boca Raton to Boynton Beach...and also along the southern lake Okeechobee towns.

Otherwise, I do believe it would be correct to say that the entire eastern populated portion of south Florida experienced cat 1 or less sustained winds, with a small portion experiencing cat 2 sustained winds. Certainly gusts measured 120mph+ in some areas...but too many people seem to think the gust is the hurricane's strength.

My (unprofessional) anemometer saw sustained cat 2 windstrength for several minutes at a time, numerous times throughout the hurricane...and measured gusts to 112mph before the mount gave up and blew the anemometer down. I'm sure we had gusts over 112mph, as I saw gusts with more strength than those measured ones tear through my back and front yard...with lots more force than we saw during Irene, Frances, Jeanne, or Katrina. Only the most powerful gusts seemed capable of creating the total horizontal white-out conditions, and these did the most prominent structural and tree damage.

I would be willing to bet that much of northern Broward county, Boca Raton, Delray Beach, and Boynton Beach saw cat 2 sustained (at around 100mph), with gusts to 120MPH or so. I would doubt that very many other places in southeast Florida saw anything above cat 1 sustained, with occasional gusts over 100mph.

I have doubts that even the worst parts of Wilma on the southeast coast reached a sustained cat 3 strength...certainly some of the more intense bands on either side of the eyewall delivered gusts at that level...but if sustained winds are measured as a 60-second-constant, I don't think any city saw that.

Either way...I've got plenty of respect for a cat 1 storm...let alone a cat 2. 90-100MPH with gusts to 120-130MPH and the threat of tornadoes and damaging debris sounds pretty bad to me, and I'd prefer to limit my encounters with these storms, at least in my backyard!

That explains it. What others said also explains it. However, I meant I think my area did NOT get Category Three SUSTAINED winds; I meant that my area may have gotten Category Three GUSTS, with sustained winds closer to around Category One or Category Two force.

By the way, do you live in eastern Boca Raton, Zackiedawg?

[Forecaster Colby]

Given the damage, I'd say more a minimal Cat 4 at landfall and a minimal 3 when she moved off the east coast. The damage wasn't as bad as, say, Charley, but that's because Wilma was hauling.

[Derek Ortt]

Wilma and Charley were moving at nearly the same speeds

had the SW Coast of Forida been populated where the southern eye wall made landfall, damage likely would have been at least as bad as Rita along the coast

[MiamiensisWx]

Before landfall, both Charley and Wilma were moving around 20MPH. When they made landfall, Charley was moving at 22MPH, while Wilma was moving around 23MPH.

[MiamiensisWx]

most of SE Fla only received cat 1 conditions, and low end cat 1 at that

the cat 2 winds were very isolated and contained to broward

Sorry to sound rude, but I heard that a weather station near or around the southern areas near Lake Okeechobee (not in Broward County) reported sustained winds around 103MPH, or Category Two force.

[f5]

the strongest part of Wilma's eyewall was the south side that was over the everglades.as Far as Charley goes his damage is almost there with Andrew but not quite that catastrophic

[MiamiensisWx]

the strongest part of Wilma's eyewall was the south side that was over the everglades.as Far as Charley goes his damage is almost there with Andrew but not quite that catastrophic

In the areas of the strongest winds in Charley, damage looked almost like a miniature version of Andrew's destruction.

Also, Wilma's southern eyewall was over Broward County and the central and southern to north-central parts of Palm Beach County throughout Wilma's passage at different times. It was also, as you said, over the Everglades. The strongest of Wilma's sustained winds were definately in local spots and certain areas.

Like Andrew, Charley had a very small area of the strongest winds. Hurricane-force winds in Charley likely only covered over a several-mile-wide area, with the other areas receiving tropical storm-force winds. Charley's strongest winds might have only been in an area as low as less than 5 or 4 miles.