Atlantic Hurricanes: Reanalyzed

[k***]

Iris 2001-- another very small cyclone-- generated winds much stronger (125 kt) with a pressure that was just as little lower (948 mb). Iris and King are analogous in terms of dimensions, and these wind-pressure combos correlate nicely.

I thought Iris' SLP was a bit lower. I guess even taking into account the fact that it hit Belize instead of somewhere further north, it is possible to use this storm as a rough analog for King and conclude that King could have been a fake 4.

[k***]

You always have to assume that the highest winds weren't sampled.

Sure.

[k***]

How about this doozy:

Ten Category 5 hurricanes were recorded in

the Atlantic Basin from 1992-2007 [Hurricane Andrew (1992) to Hurricane Felix

(2007)]. A new (fairly objective) methodology was created to determine how many

of these ten recent Category 5s would have been recorded as Category 5s if they had

occurred during the late 1940s using only the observations that would have been

available with late 1940s technology. A new best track intensity was drawn for the

entire lifetime of these ten recent Category 5s (using late 1940s technology), and it is

found that only two of these ten (Andrew and Mitch) would have been recorded as

Category 5 hurricanes if they had occurred during the late 1940s period.

[HurricaneJosh]

I thought Iris' SLP was a bit lower. I guess even taking into account the fact that it hit Belize instead of somewhere further north, it is possible to use this storm as a rough analog for King and conclude that King could have been a fake 4.

Omg. So provocative. I fixed your post.

Iris was 948 mb at landfall: http://www.nhc.noaa.gov/2001iris.html

Granted, it was deep in the tropics-- much lower down than King-- but on the other hand, it wasn't explosively deepening as it came ashore. The pressure was nudging down, but it was not bombing out like King.

Iris supports the conclusion that King was a 4. Thx.

[k***]

Omg. So provocative. I fixed your post.

Iris was 948 mb at landfall: http://www.nhc.noaa.gov/2001iris.html

Granted, it was deep in the tropics-- much lower down than King-- but on the other hand, it wasn't explosively deepening as it came ashore. The pressure was nudging down, but it was not bombing out like King.

Iris supports the conclusion that King was a 4. Thx.

[k***]

Figures that we missed some good east atlantic action back then

44 gets three new storms, including a hurricane that formed in October near the Azores and made landfall in Portugal as a TS.

46 gets another Azores hurricane--direct landfall...destroyed a military base there.

[k***]

Falls from 2nd to 5th place. Now having the top 4 being in the current +AMO cycle.

Dog dropping from 160 kts to 125 is loltastic.

[icebreaker5221]

I like these changes. Note that all 4 hurricane "upgrades" were to either SW FL or SE FL, further support the fact that S. FL is a nice bullseye for major hurricanes.

The fact that the Great Atlantic Hurricane is no longer a major for the mid-Atlantic, the Maine hurricane was reduced to a TS, and Dog being weakened so drastically at high latitudes should help shut up some of the northeast and mid-Atlantic weenies who want to post every fantasy forecast of a major landfall in their area since climo is now even MORE against them!

[icebreaker5221]

Note that all 4 hurricane "upgrades" were to either SW FL or SE FL

Sorry, I meant to say all 4 FL landfalls upgraded to cat 4 were in S. FL. There were more hurricane upgrades than these...

[k***]

I like these changes. Note that all 4 hurricane "upgrades" were to either SW FL or SE FL, further support the fact that S. FL is a nice bullseye for major hurricanes.

The fact that the Great Atlantic Hurricane is no longer a major for the mid-Atlantic, the Maine hurricane was reduced to a TS, and Dog being weakened so drastically at high latitudes should help shut up some of the northeast and mid-Atlantic weenies who want to post every fantasy forecast of a major landfall in their area since climo is now even MORE against them!

I think that the most interesting conclusion of the thesis is how things were doubly screwed up:

1. the ones they called cat 5's back then weren't actually cat 5's (save carol)

2. real cat 5's would be underrepresented.

Thank god for new technology.

[icebreaker5221]

I think that the most interesting conclusion of the thesis is how things were doubly screwed up:

1. the ones they called cat 5's back then weren't actually cat 5's (save carol)

2. real cat 5's would be underrepresented.

Thank god for new technology.

I agree. The modern technology really goes a long way, and also makes the hobby of tracking hurricanes a lot more enjoyable!

[HurricaneJosh]

I like these changes. Note that all 4 hurricane "upgrades" were to either SW FL or SE FL, further support the fact that S. FL is a nice bullseye for major hurricanes.

Dude, come on-- this is hardly a new insight.

The fact that the Great Atlantic Hurricane is no longer a major for the mid-Atlantic, the Maine hurricane was reduced to a TS, and Dog being weakened so drastically at high latitudes should help shut up some of the northeast and mid-Atlantic weenies who want to post every fantasy forecast of a major landfall in their area since climo is now even MORE against them!

You're harsh, but I kind of agree. There's a lot of crazy, unsubstantiated mythology about hurricane events N of the Carolinas, and modern reanalysis is poking holes in that mythology. In the end, probably only the great 1938 'cane and maybe Carol 1954 will survive reanalysis with their splendor intact. The rest are taking a beating. (As a native Long Islander, I feel like I have a right to utter this cold truth.)

I'm still astonished by all the FL upgrades for the late 1940s. Just holy crap!

[A-L-E-X]

Dude, come on-- this is hardly a new insight.

You're harsh, but I kind of agree. There's a lot of crazy, unsubstantiated mythology about hurricane events N of the Carolinas, and modern reanalysis is poking holes in that mythology. In the end, probably only the great 1938 'cane and maybe Carol 1954 will survive reanalysis with their splendor intact. The rest are taking a beating. (As a native Long Islander, I feel like I have a right to utter this cold truth.)

I'm still astonished by all the FL upgrades for the late 1940s. Just holy crap!

Josh, I think the hurricane "drought" that has occurred up here since Bob had already started to poke holes in the mythology. I've talked to several people around here who dont take hurricanes seriously and dont think we can get hit.

BTW I know this is was a long time ago, but the Great Colonial Hurricane survived intact too I wonder what the total numbers of majors that hit this area from that point to today would be after reanalysis?

BTW not to take anything away from the 1944 hurricane, but the hard truth is that Cat 2 is plenty bad enough and can easily cause as much damage as a major up here. I remember reading somewhere that even a Cat 1 can cause as much damage up here as a Cat 3 down south.

After having lived through Dec 1992 (noreaster with three days of hurricane force gusts) and knowing first hand what a surreal amount of damage a storm like that can cause, I have no illusions and consider all hurricanes to be dangerous, regardless of the category. Still, theyre really fun to track and even more awesome to chase

[vortex95]

<br />Actually, it's a very reasonable conclusion given that RMW, which is insanely small.  This aside, the Miami WBO had 106 kt sustained.  It wasn't at a standard height, but it was a solid reading.  All of this aside, wind damage was very heavy in the core region-- the city got really raked.  For years I've thought it might have been a Cat 4, and it seems to me to be a completely logical conclusion.<br />

<br /><br /><br />

Also of note:

"but this is the first occasion observed in Florida, to this writer’s knowledge, of lightning and thunder right near the center where wind velocities were 95 to 125 mph. There were several brilliant lightning flashes with thunder during the height of the storm, observed by the writer, and one discharge occurred very near the Weather Bureau Office with a sharp crack of thunder heard about the deafening scream of the wind, only a few minutes before the lull occurred."

Tell-tale sign of intense eyewall updraft/downdraft couplets, most efficiently transporting down the extremely high winds found only a few hundred

feet AGL. So Cat 4 winds w/ a higher than expected pressure are reasonable in this case.

[HurricaneJosh]

Josh, I think the hurricane "drought" that has occurred up here since Bob had already started to poke holes in the mythology. I've talked to several people around here who dont take hurricanes seriously and dont think we can get hit.

The current Northeast hurricane drought-- that started after Bob 1991-- reminds me of the drought that preceded 1938. Not only was the 1938 cyclone by far the most ferocious in this region-- but it came after a very long period of no tropical activity up there, when awareness was most certainly at an all-time low. Add to this the complete lack of warnings, and people on Long Island and SNE must have been completely mystified as the cyclone struck-- like one big WTF??

BTW I know this is was a long time ago, but the Great Colonial Hurricane survived intact too I wonder what the total numbers of majors that hit this area from that point to today would be after reanalysis?

Honestly, I'm a bit skeptical Re: any reanalysis back that far. Even the official reanalysis start date-- 1851-- is pushing it a little, in my book.

BTW not to take anything away from the 1944 hurricane, but the hard truth is that Cat 2 is plenty bad enough and can easily cause as much damage as a major up here. I remember reading somewhere that even a Cat 1 can cause as much damage up here as a Cat 3 down south.

Agreed. The 1944 cyclone hit the East End of Long Island with winds of 95 kt. That is a whopping value for this region-- for the architecture, the vegetation, etc. A strong Cat 2 is serious business anywhere-- even in the South. Ike was a 95-kt storm at landfall in TX.

After having lived through Dec 1992 (noreaster with three days of hurricane force gusts) and knowing first hand what a surreal amount of damage a storm like that can cause, I have no illusions and consider all hurricanes to be dangerous, regardless of the category. Still, theyre really fun to track and even more awesome to chase

Yep. A solid Cat 1-- like Gloria 1985-- can do a real number on Northeast communities. The bottom line is that any 65-kt cyclone up there is a huge event.

P.S. I'll be stopping into NYC for a a few days next week or the week after. Let's try to really get together this time!!

[HurricaneJosh]

Also of note:

"but this is the first occasion observed in Florida, to this writer’s knowledge, of lightning and thunder right near the center where wind velocities were 95 to 125 mph. There were several brilliant lightning flashes with thunder during the height of the storm, observed by the writer, and one discharge occurred very near the Weather Bureau Office with a sharp crack of thunder heard about the deafening scream of the wind, only a few minutes before the lull occurred."

Tell-tale sign of intense eyewall updraft/downdraft couplets, most efficiently transporting down the extremely high winds found only a few hundred

feet AGL. So Cat 4 winds w/ a higher than expected pressure are reasonable in this case.

Oh, wow-- I didn't even think of that-- that that bit of novelty might also be another clue Re: the cyclone's intensity.

Thanks for chiming in-- I'm glad you also feel that the Cat-4 conclusion is reasonable. (Pro mets have extra cred. )

[Normandy]

For those that experienced Andrew, was this similar type of thing occurring with frequent lightning? Off all the Charley videos I have seen I don't recall seeing any lightning in any of the videos, so perhaps all rapidly intensifying hurricanes don't possess this? I remember the flight into Felix recon mentioned intense lightning as well.

[HurricaneJosh]

For those that experienced Andrew, was this similar type of thing occurring with frequent lightning? Off all the Charley videos I have seen I don't recall seeing any lightning in any of the videos, so perhaps all rapidly intensifying hurricanes don't possess this? I remember the flight into Felix recon mentioned intense lightning as well.

That's a good question. Unfortunately there is little if any footage from Andrew's core as it crossed the FL coast, and although there's a sh*tload of Charley footage from the core region-- it was a very well-documented landfall-- I wonder if the daylight made lightning harder to see, and if the shrieking of the winds covered the thunder.

P.S. Nice to see you posting here.

[HurricaneJosh]

I'm going to post a nice map and some sexy factoids about King 1950 in a little while. The thesis is full of really detailed, interesting discussion about that one. It was a very weird system.

[A-L-E-X]

I'm going to post a nice map and some sexy factoids about King 1950 in a little while. The thesis is full of really detailed, interesting discussion about that one. It was a very weird system.

Hey Josh, could you post some maps about that Cat 5 that supposedly made landfall in Cuba? That one really fascinates me! I love analyzing old time historical storms, since we know so little about them.... its like a detective story where all the pieces are slowly falling into place.

[HurricaneJosh]

I wanted to post a little more about Hurricane King (1950), as it's a spectacular example of what I call a microcane.

While it's sort of a forgotten storm now, it's actually the severest cyclone to make a direct hit on Downtown Miami since the great 1926 'cane. Its dimensions and intensity make it a good analogue for Cyclone Tracy (1974) in Australia.

Hagen's thesis concludes King was a Cat 4 at landfall at Miami. This still has to be reviewed/accepted by the NHC's best-track committee-- it's not official HURDAT yet-- but I think he's on the right track with this.

Overview

King originated in the Caribbean on 13 October and first hit Cuba as a Cat 1 on 16 Oct. Moving N, the cyclone completely bombed out as it crossed the Florida Straits-- with the pressure dropping a whopping 33 mb in the final 14 hrs leading up to landfall at Miami at 05Z on 18 October (a little after 12 midnight local time). The cyclone's eye and core contracted dramatically during this time, so that there was very little indication in Miami of what was approaching. And when it arrived, the cyclone's ferocity caught the city by surprise.

From the USAWS report:

Outside of the reconnaissance flight on the morning of October 17th which reported 90 kt with gusts to 100 kt there was no indication of the severe intensity of the storm until it reached Miami. Due to the small size of the storm, the automatic weather station in the Florida Straits and the Coast Guard stations along the Keys gave little indication of a severe storm. Before the storm center reached Miami, forecasters were ready to admit that the storm had weakened or had been overestimated by reconnaissance. As the center reached Miami, however, it became apparent that despite its minute size, King packed a terrific punch.

Size of Eye

The cyclone's tiny eye moved NNW as it approached Miami, passing between Elliot Key and Key Biscayne up to landfall at Grove Isle-- between Coconut Grove and Vizcaya (yellow marker on map). The eye was so narrow that it actually threaded between two official reporting stations-- the Downtown Miami WBO (orange marker) and Miami Airport (purple marker). Both stations were in the RMW and skirted opposite edges of the eye, but neither had a complete calm:

* At the Miami WBO, the winds dropped to 30 kt around 05Z before picking up on the backside and reaching the max value at that station: a ferocious 106 kt S with gusts estimated at 130 kt.

* The Miami Airport had its max wind (70 kt NE gusting to 109 kt) at 0459Z, followed by a near lull (16 kt) probably a little before 0530Z.

These readings suggest the eye was small enough to thread in between these two locations, which are only ~6-8 mi apart. The analyzed eye radus is 2.6 mi, yielding a diameter of ~5 mi.

Lowest Pressure

An off-duty Miami WBO employee reported 955 mb and that is accepted as the landfall pressure. The exact time/location is unknown, but it's assumed to be ~05Z somewhere between the Miami WBO (min p: 957 mb at 0448Z) and the Miami Airport (min p: 960 mb at 0500Z).

The pressure gradient was sharp. At the Miami WBO, the pressure was below 982 mb (29.00 in) for only ~1:30.

Max Winds

The central pressure (955 mb), rapid strengthening trend (33-mb drop in 14 hrs), tiny RMW (3-5 n mi), and latitude (~25N) yield an estimated max sustained wind of 115 kt at landfall-- making it a Cat 4.

Size of Wind Field

Wind damage was severe but the swath across Greater Miami was very narrow-- only ~14 mi. (Some estimates put the swath at only 7-10 mi wide.) The gradient from minor to severe damage was so sharp-- only 0.25 to 0.5 mi-- that meteorological investigators at first thought it was caused by a tornado-- however, they concluded that it was caused by straight-line hurricane winds.

Hagen suggests that while the RMW is officially analyzed to be 5 n mi, it actually might have been as small as 3 n mi. Essentially, King's wind core was like a very large EF3 tornado.

Very high winds did not last long in any one location. The USAWS report indicates that "In only one hour did more than 75 miles of wind pass the [Miami WBO] station"-- in other words, winds averaged hurricane strength for only an hour-- and "Five minute maximums were of hurricane force only two hours."

All of the data/conclusions in this summary are derived from various parts of Hagen's thesis and/or from his sources.

--

RAW DATA

Miami WBO

0430Z: 100 kt NE, 962 mb

0440z: 84 kt NE (5 min) (max 5-min w)

0448Z: 957 mb (min p)

?Z: 30 kt SE (min w in RMW)

0515-0530Z: 106 kt S G (est) 130 (max 1-min w)

0530Z: 90 kt SW, 968 mb

Miami Airport

0459Z: 70 kt NE G109 kt (max 1-min w)

0500Z: 960 mb (min p)

?Z: 16 kt NW (min w in RMW) (probably just before 0530Z)

0530Z: 15-20 kt W, 967 mb

[vortex95]

<br />That's a good question.  Unfortunately there is little if any footage from Andrew's core as it crossed the FL coast, and although there's a sh*tload of Charley footage from the core region-- it was a very well-documented landfall-- I wonder if the daylight made lightning harder to see, and if the shrieking of the winds covered the thunder.<br /><br />P.S.  Nice to see you posting here. <img src='http://208.71.34.143/public/style_emoticons/default/smile.gif' class='bbc_emoticon' alt='' /><br />

Lightning in Hurricane Andrew:

http://www.nws.noaa.gov/im/pub/srta9244.pdf

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA299713&Location=U2&doc=GetTRDoc.pdf

Second paper shows considerable CG activity at landfall around the eye.

This thread discusses lightning associated w/ recent hurricanes, including Charley:

http://www.stormtrack.org/forum/printthread.php?t=17862

[aslkahuna]

That's a good question. Unfortunately there is little if any footage from Andrew's core as it crossed the FL coast, and although there's a sh*tload of Charley footage from the core region-- it was a very well-documented landfall-- I wonder if the daylight made lightning harder to see, and if the shrieking of the winds covered the thunder.

P.S. Nice to see you posting here.

During their RI phases, hurricanes Katrina, Rita and Wilma all had considerable eyewall lightning. In Jim Leonard's long form video of Typhoon Omar on Guam there's the famous close CG and thunder during the inbound eyewall passage. However, during the return wind eyewall as the storm reintensified after leaving Guam, the twilight period made it possible to see the lightning much easier and it looked as frequent as an Oklahoma thunderstorm.

Steve

[kwt]

Yeah I think there is enough to suggest King was a category-4, it reminds me of a slightly less matured version of Charley, coming up at a different angle but there do seem to be some interesting comprasions including the small size and the way its core really tightened up nicely.

That sustained wind of 106kts is impressive, though on its own I don't think its really enough to prove its a category-4, but given everything else you'd have to err towards a category-4 landfall...or at least a category-4 peak just offshore, esp given that 106kts was highly unlikely to be the peak wind.

[HurricaneJosh]

Lightning in Hurricane Andrew:

http://www.nws.noaa.gov/im/pub/srta9244.pdf

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA299713&Location=U2&doc=GetTRDoc.pdf

Second paper shows considerable CG activity at landfall around the eye.

This thread discusses lightning associated w/ recent hurricanes, including Charley:

http://www.stormtrack.org/forum/printthread.php?t=17862

Oh, very cool. Thanks for these. I guess it's less rare than I realized!

During their RI phases, hurricanes Katrina, Rita and Wilma all had considerable eyewall lightning. In Jim Leonard's long form video of Typhoon Omar on Guam there's the famous close CG and thunder during the inbound eyewall passage. However, during the return wind eyewall as the storm reintensified after leaving Guam, the twilight period made it possible to see the lightning much easier and it looked as frequent as an Oklahoma thunderstorm.

Steve

I have Jim's Omar video, so I'll take a second look. For some reason I don't remember that. I guess it makes sense that Omar would have lightning, as it was strengthening at a good rate as it passed over Guam. That was a good score for Jim-- I ink he considers it one of his best.

I realize that, of all my chases, I haven't been in the core of a hurricane that was really bombing out-- like, rapidly intensifying-- so that probably explains why I've never seen lightning in a 'cane. (Dean 2007, as intense as it was, was intensifying at a steady, non-explosive rate, and, anyhoo, I missed the core by a couple of miles in that one. Grrr.)

What do you think of King? Based on the evidence, does Cat 4 seem like a good call to you?

[HurricaneJosh]

Yeah I think there is enough to suggest King was a category-4, it reminds me of a slightly less matured version of Charley, coming up at a different angle but there do seem to be some interesting comprasions including the small size and the way its core really tightened up nicely.

That sustained wind of 106kts is impressive, though on its own I don't think its really enough to prove its a category-4, but given everything else you'd have to err towards a category-4 landfall...or at least a category-4 peak just offshore, esp given that 106kts was highly unlikely to be the peak wind.

I agree with your Charley analogy-- I think there are lots of similarities here, and I imagine King would have had a similar radar presentation-- with the little red ring around a tiny eye.

Re: the 106 kt at Miami WBO... I agree that it in itself is not evidence of Cat 4, because 1) it was at a nonstandard height (above 10 m) and 2) Cat 4 starts at 114 kt. Still, it's a solid reading.

Hagen-- the author of the thesis who concluded it was a Cat 4-- derived the 115 kt based on formulas factoring in 1) the cyclone's central pressure (955 mb), 2) the tiny RMW (3-5 n mi), 3) the rapid intensification (33-mb drop in 14 hrs), and 4) the cyclone's latitude (~25N). The surface obs are helpful, but in the end he doesn't rely on them. See his reasoning in the first post of this thread. It makes sense, I think.

[kwt]

It'll be interesting to see what happens when the offical reports come through about this system, from the looks of things you could make a solid argument for anything from 105-115kts and the author has chosen the top end probably due to the fact it was bombing out and the strongest winds would get better mixed down.

I wouldn't be surprised mind you if the offical report comes out a little more conservative and go with something of a middle ground and up it to 110kts officaly, though 115kts is just as possible as well looking at the data.

[Sickman]

I find that Portugal TS landfall very interesting. Some of those Azores systems seem to have unique characteristics that allow them to maintain themselves longer, despite what would seem like an unfavorable environment and climatology.

[Juliancolton]

It should be noted (or emphasized, if it's been noted already) that this particular reanalysis is not official and has not been reviewed or approved by the Best Track Committee. I first saw this thesis a couple weeks ago, and I'm a bit cautious of accepting any changes as fact. Nonetheless, I think it's obvious that Dog '50 will ultimately be downgraded by HURDAT, for example, and this paper provides a plethora of valid information by which to base their alterations on. What I'm currently more interested in is the official HURDAT reanalysis from 1926 to 1930, which was released just a couple days ago publicly. The relevant discussions can be found here:

1930: http://www.aoml.noaa.gov/hrd/hurdat/nhcreply-sep2010.htm

1929: http://www.aoml.noaa.gov/hrd/hurdat/nhcreply-jul2010.htm

1928: http://www.aoml.noaa.gov/hrd/hurdat/nhcreply-jun2010b.htm

1927: http://www.aoml.noaa.gov/hrd/hurdat/nhcreply-jun2010.htm

1926: http://www.aoml.noaa.gov/hrd/hurdat/nhcreply-may2010.htm

[HurricaneJosh]

It'll be interesting to see what happens when the offical reports come through about this system, from the looks of things you could make a solid argument for anything from 105-115kts and the author has chosen the top end probably due to the fact it was bombing out and the strongest winds would get better mixed down.

I wouldn't be surprised mind you if the offical report comes out a little more conservative and go with something of a middle ground and up it to 110kts officaly, though 115kts is just as possible as well looking at the data.

Yeah, it wouldn't surprise me to see the best-track committee do exactly what you say-- split the difference and settle on 110 kt. However, I think all of the factors (mentioned above) make a really good case for adding 10 kt to the standard wind speed for that pressure at that latitude (yielding 115 kt).