Hurricane Irma 2017

Jul 5, 2009
844
522
21
Newtown, Pennsylvania
From news reports this morning it sounds like the southwest coast didn't get quite the level of surge expected. Is that because of the pre blowout tides / "reverse surge" from the offshore wind? And/or because the onshore winds in the southern eyewall weren't as strong? There didn't seem to be much left to the southern eyewall the whole day, and even just watching live coverage from Naples you never saw much wind return after the eye had passed.


Sent from my iPad using Tapatalk
 

Jack Sillin

Enthusiast
Sep 10, 2017
6
0
0
Yarmouth Maine
From news reports this morning it sounds like the southwest coast didn't get quite the level of surge expected. Is that because of the pre blowout tides / "reverse surge" from the offshore wind? And/or because the onshore winds in the southern eyewall weren't as strong? There didn't seem to be much left to the southern eyewall the whole day, and even just watching live coverage from Naples you never saw much wind return after the eye had passed.


Sent from my iPad using Tapatalk
SW coast didn't get the surge quite as bad due to the weaker nature of the storm as well as the track slightly to the east. If the center tracked offshore, those 130 mph offshore winds observed in Naples and at Marco would've been much more onshore and then you would've been in big trouble. Weakening due to Cuba also played a part.. Weakening Cat 3 =/= steady Cat 4/5. It was bad for many areas, but nowhere near as bad as it could've been!
 
Jun 1, 2008
467
362
11
Chattanooga, TN
www.linkedin.com
Lower surge west was 100% due to the track. Saffir-Simpson scale is obsolete. Irma ACE number remained exceptional. East coast of Florida had impressive (a couple records) surge considering landfall was on another coast!
 
Jul 5, 2009
844
522
21
Newtown, Pennsylvania
Lower surge west was 100% due to the track. Saffir-Simpson scale is obsolete. Irma ACE number remained exceptional. East coast of Florida had impressive (a couple records) surge considering landfall was on another coast!

IDK, do you really think the lower surge on the west coast of FL was only due to the track? The track really wasn't all that different than forecast within the last 24 hours that it was affecting FL. The surge forecasts were high even when it was known the hurricane would be along the west coast, meaning it would have to be driven by the southern eyewall which would bring the onshore flow. But at least based on radar, the southern eyewall was already eroding at 7:15 in the morning while Irma was still in the Keys.

4dbf8088af9c9ba4fc0965fbe76c6997.jpg
 

Jack Sillin

Enthusiast
Sep 10, 2017
6
0
0
Yarmouth Maine
IDK, do you really think the lower surge on the west coast of FL was only due to the track? The track really wasn't all that different than forecast within the last 24 hours that it was affecting FL. The surge forecasts were high even when it was known the hurricane would be along the west coast, meaning it would have to be driven by the southern eyewall which would bring the onshore flow. But at least based on radar, the southern eyewall was already eroding at 7:15 in the morning while Irma was still in the Keys.

View attachment 16374
Track was a significant player in the lack of surge in Tampa/Ft Meyers area. Onshore track to the east of those cities prevented RFQ surge and the earlier landfall helped accelerate weakening of southern eyewall. Furthermore, this would me a MUCH different conversation had it not been for the track wobble into Cuba. Was it 100% track? No, dry air and shear played a part, but it was probably >95% track :)
 
Jul 5, 2009
844
522
21
Newtown, Pennsylvania
Track was a significant player in the lack of surge in Tampa/Ft Meyers area. Onshore track to the east of those cities prevented RFQ surge and the earlier landfall helped accelerate weakening of southern eyewall. Furthermore, this would me a MUCH different conversation had it not been for the track wobble into Cuba. Was it 100% track? No, dry air and shear played a part, but it was probably >95% track :)


I agree with respect to Tampa and Fort Meyers. But some of the highest surge was forecast on the southwestern coast, south of Naples. The hurricane was forecast to be offshore at that latitude, and it was in fact still offshore. Even the right front quadrant would have produced more of an offshore wind at that location, so it had to be the onshore flow in the southern eyewall that was expected to produce the surge, and I think that southern eyewall had weakened considerably.

Not trying to be argumentative, obviously there are a ton of variables in the mix. I am mainly trying to understand if my theory is correct and if the southern eyewall did in fact weaken, because I can only go on the weakened radar reflectivity image that I saved and posted above. I realize this doesn't necessarily mean that the winds had also weakened, so that's what I am trying to find out, how much of a factor was it. By the time the hurricane had passed north of the Keys, there were no more surface wind observations coming from that station so I don't know what the winds in the southern eyewall were like. But I did notice from live reporting from Naples that after the eye had passed there wasn't much wind blowing at all.




Sent from my iPhone using Tapatalk
 
Jul 5, 2009
844
522
21
Newtown, Pennsylvania
Unless you have a death wish. Stay away from Key West if Irma's path or core heads that way. Highway 1 is a death trap. There are places where the ocean is literally lapping at the edges of the highway. I remember telling Jim Leonard that one of my worse fears was to be trapped on that highway -- and it's a very long road, about 160 miles from Miami. Just thought I'd throw this out in case someone was considering it.

Stay safe.

Warren, just wondering about the results of your chase, in an early post you said you were heading to someplace in FL, I can't remember where but I'm sure your initial target changed anyway.

Apparently there were chasers in Key West at some sturdy "concrete hotel of at 7 (?) stories built in 1926." I also learned that Key West has an 18 foot elevation but I'm not sure how much of the island is at that elevation. Would you have considered that scenario safe or do you think Key West turned out OK only because the right front quadrant missed the island? I might actually consider trying a Key West intercept in the future if there is an opportunity. There were also chasers in Big Pine Key, now THAT seems suicidal to me but then again I don't know too much about that particular island...


Sent from my iPhone using Tapatalk
 
Wild chase considering the last few hours of drama over where Irma would go. Could write volumes about the last week. The eastern coast was still my target -- despite a lot of media people blasting off Friday night to head west. I surmised the accumulated surge momentum would still effect the east coast. The biggest surprise was wind. It will be interesting to study the wind reports in the Miami area. I could not stand for long periods of time as the wind was simply too strong to work in. Debris from skyscrapers was a constant threat. The was wind coming directly off the water, not compressed winds through structures. I saw at least two strong vortices move in from the east. The first struck me on the walkway next to the bay and nearly carried me into the water after forcing me to slide on the concrete for about 10 feet. It took out a fortified glass and brick partition behind me. I ended up with some cuts but overall, I was extremely lucky. Got some great footage, which I never expected after Irma kept heading west. I spend the rest of the evening and the next morning checking the area for victims. Fortunately, the only thing I found was a small puffer fish washed ashore and gasping for water. I put it in the water and it swam away. I figured I owed Neptune a favor.

P9100259-small.png
 

cdcollura

EF5
Jun 12, 2004
1,386
137
11
49
Sunrise, Florida
www.sky-chaser.com
Good day all,

This is my chase log for hurricane Irma in SW Florida. Details are below...

Summary: This area shows pictures taken from the interception and observation of powerful category-four hurricane Irma in southwestern Florida mainly during its landfall in Marco Island and into Naples (Collier County). Hurricane Irma was a deadly and powerful hurricane that made its way across the Atlantic from the Cape Verde Islands off Africa in the first days of September 2017. Reaching category 5 strength, with 185 MPH winds, the storm devastated the northern Virgin Islands, passing north of Puerto Rico, then into the southeastern Bahamas. On September 9, the storm scraped across the northern Cuban coast as a category 5 storm with 160 MPH winds, then turned north and passed east of Key West with 140 MPH winds early on September 10. Later that same day, the storm made its final landfall as a strong category 3 / minimal category 4 with 125 to 130 MPH sustained winds at Marco Island. Steadily weakening thereafter, Irma continued north through Naples and east of Fort Meyers, becoming a tropical storm early on September 11 in northern Florida and Georgia. Irma finally met its end to a destructive 13-day long route from west of Africa (around Aug 30) to the USA as it became a tropical depression and dissipated over the SE USA on September 12. Irma caused extensive damage (and even catastrophic) during its journey, with several landfalls (Barbuda and British Virgin Islands, Cuba, and Florida). This chase was a "local" chase in Florida, with chaser Derek Sibley joining me. We headed out of my area in Broward County and targeted the SW Florida coast for the September 10 landfall, which would be during mid-day and ideal. We stayed at storm chaser Mark Farmer's place in Naples, helping him with boarding up and such, and joined Brett Adair, Caleb Elliott, and many other chasers (who were also in TX in Harvey) at the American Sports Pub (only place open on Sept 9) for a pre-chase party. For the interception, we chose a parking garage at a beach-front resort early on September 10, on the southern tip of Marco Island (buildings there rated for category 5 winds). The eyewall and calm eye of Irma was experienced at this location. After the storm, we went back out and worked our way out of Marco Island, observing extreme flooding and some storm surge. After checking if Mark Farmer was OK (he stayed in Naples), we left Naples and headed back east to my place in Broward County. Power was out at my place for several days, and tree damage and some roofing tiles missing. The total mileage was 292 miles.

irmeyew1.jpg

This is a picture taken from inside the inner eyewall of hurricane "Irma" as it was making landfall in Marco Island, Florida at roughly 3:15 PM EDT on September 11, 2017. The ferocious winds here are blowing with gusts exceeding 130 MPH, tearing apart palm trees, throwing debris across the area, and nearly tearing my shirt right off my body. This scene was lit by a brilliant flash of lightning and thunderclap barely audible over the roar of the wind. This was about 10 minutes before entering the calm eye of Irma (which had some sun peeking through).

irmrad1.jpg

These are two annotated images showing hurricane Irma as it made its final approach and landfall in the Florida Keys and into southwest Florida. The left image is a visible satellite image as the hurricane moving along the northern Cuban coast as a borderline category 5 hurricane late on September 9. The yellow arrow shows how the storm was to turn north, cross the lower Florida Keys, and move into the southwest Florida coast. To the right is a radar image (reflectivity) as the hurricane core was approaching Marco Island with winds at least 130 MPH. The eyewall is slightly eroded on the south side due to some dry air drawn into the "moat" region between the concentric eyewalls. The northern eyewall is where there is violent rain and also contains all the wind dynamics. The convective "chimney" of the storms right-front eyewall is the red region. To the north of the calm eye and hurricane core, numerous chasers (from Spotter Network) appear in Marco Island as red dots. The cross-hairs is my GPS location at the time.

Full video of Hurricane Irma is below...


Pictures are below...

irm08.jpg

Above: During the morning of September 10, from Naples and into Marco Island, the powerful offshore flow is pusing the waters of the Gulf of Mexico OUT to sea, resulting in a "negative surge". Marinas and docks are left high and dry and at the Gulf beaches you could actually walk great distances out on the sea floor!

irm12.jpg

Above: Myself wedging myself between the side and a concrete pillar during the eyewall as the wind tries to rip my clothes right off my body.

irm15.jpg

Above: View looking west inside the eye of Irma during nearly calm winds at about 3:30 PM. Winds became light and variable, and a minimum central pressure as low as 937 MB was measured inside the eye by Derek and I.

irm19.jpg

Above: Severe street flooding in the southern portions of Marco Island late in the day on September 10.

irm23.jpg

Above: View of Gulf of Mexico and storm surge pushing on shore in Naples, Florida at arund dusk on September 10. Winds here have decreased to 45 MPH or so, with tides 5 feet or so above normal (surge was less than the feared 10 to 15 feet predicted). This hurricane surf and surge here was pushing ashore and spilling into the residential streets, causing severe flooding. The view here is to the north-northwest.