Atlantic Tropical Action 2012 - Part II

[andyhb]

2008 to this year is quite long a period also, so your overall point stands. But for all practical purposes, you gotta count Ike as a major hurricane level impact. The press and the authorities certainly treated Ike as an impending catastrophic landfall, and Ike did manage to cause $30 billion damage (updated total in the 2010 update to "Deadliest, Costliest.." document). There would have been no discernable difference in impact if Ike had acquired another 5 knots in sustained winds before landfall.

Agreed on all counts, Ike was something else.

[HurricaneJosh]

Oh, I definitely wasn't trying to suggest the expansion of the major landfall definition. I was just responding to the idea of complacency, and suggesting that 2008 was definitely one of those "big deal years."

OK, I gotcha.

Did you see my post earlier today? I am wondering if the wind speeds for the whole SS scale need to be revised downward to more accurately reflect what's observed on the ground.

As you and I have noticed, an actual 1-min/10-m wind reading of 85 kt from an official land station in a landfalling hurricane always seems so nuclear-- even though this barely qualifies as Cat 2.

[andyhb]

That said, if Ike was a Cat 4/5 in the Gulf, we'd probably be talking on the level of Katrina in terms of damage or worse (perhaps even regarding deaths).

[Drz1111]

2008 to this year is quite long a period also, so your overall point stands. But for all practical purposes, you gotta count Ike as a major hurricane level impact. The press and the authorities certainly treated Ike as an impending catastrophic landfall, and Ike did manage to cause $30 billion damage (updated total in the 2010 update to "Deadliest, Costliest.." document). There would have been no discernable difference in impact if Ike had acquired another 5 knots in sustained winds before landfall.

Exactly. It's highly likely that Ike would be considered a major if it had made landfall in, say, 1930, even post-reanalysis, and drawing anything but the broadest conclusions with respect to the totally crappy historical dataset is a fools errand - especially as it seems, IMO, that better observational technology is revealing that true major hurricane status is harder to achieve at a US landfall that was thought for many decades.

[gymengineer]

OK, I gotcha.

Did you see my post earlier today? I am wondering if the wind speeds for the whole SS scale need to be revised downward to more accurately reflect what's observed on the ground.

As you and I have noticed, an actual 1-min/10-m wind reading of 85 kt from an official land station in a landfalling hurricane always seems so nuclear-- even though this barely qualifies as Cat 2.

Which thread? I did a quick look and didn't see anything you thread-whore : )

Anyway, I laughed at your edit to your previous comment. You must have built up this image of me forsaking all technical precision for the soft human-impact questions. That's not the case- I've just been looking at the separation of the two areas of focus.

One of the most 'wtf' posts was someone posting about maybe Isaac shouldn't be designated a hurricane because there weren't land reporting stations with 74 mph sustained (1 or 2 min depending on ASOS or not) winds.

[HurricaneJosh]

Exactly. It's highly likely that Ike would be considered a major if it had made landfall in, say, 1930, even post-reanalysis, and drawing anything but the broadest conclusions with respect to the totally crappy historical dataset is a fools errand, especially as it seems, IMO, that better observational technology is revealing that true major hurricane status is harder to achieve at a US landfall that was thought for many decades.

"Totally crappy historical dataset"? My, you sure are quick to dismiss the work of the leading researchers and scientists in this field.

I wonder what great contributions you've made to the study of tropical cyclones.

[HurricaneJosh]

Which thread? I did a quick look and didn't see anything you thread-whore : )

Anyway, I laughed at your edit to your previous comment. You must have built up this image of me forsaking all technical precision for the soft human-impact questions. That's not the case- I've just been looking at the separation of the two areas of focus.

Yeah, I did add onto it a little. I was trying to flesh out my point-- not to demonize your viewpoint, which I respect.

One of the most 'wtf' posts was someone posting about maybe Isaac shouldn't be designated a hurricane because there weren't land reporting stations with 74 mph sustained (1 or 2 min depending on ASOS or not) winds.

Well, that's absurd. Whenever someone says that, I know they're a total newbie to this discussion-- if they think a hurricane's wind field is so simple, and the area of max winds so large, that we can just assume land stations will always sample the highest winds. Absurd.

That having been said, I've had some concerns lately Re: the disparity between best-track winds and what is observed by stations that seem to be reasonably well-situated in the core. I don't feel like the values need to match, but maybe be within a certain factor of each other.

[Superstorm93]

I'm honestly not surprised at all that we've had so many cyclones in the sub-tropical Atlantic so far.

This has been the pattern over the past 3-4 years now.

[gymengineer]

That having been said, I've had some concerns lately Re: the disparity between best-track winds and what is observed by stations that seem to be reasonably well-situated in the core. I don't feel like the values need to match, but maybe be within a certain factor of each other.

You must already have a "gut feeling" answer to your concern, with data that will continue to confirm what you know to be true. I think that hurricanes making landfall can be broken into 5 broad categories:

1) Rapidly intensifying into landfall (think Charley)

2) Steadily, but gradually, intensifying into landfall (think Hugo)

3) Steady state into landfall (think Frances)

4) Steadily, but gradually, weakening into landfall (think Floyd)

5) Rapidly unraveling into landfall (think Lili)

Given all the data regarding these hurricanes, it's pretty clear that the recent push for more precise estimates given the SMFR and other data sources is yielding to more accurate landfall estimates. Compare Lili to Carmen, for example. Did you see Carmen's radar right before landfall? It's much worse than Katrina's. Also, perusing the land observations, Carmen seems a prime candidate to be downgraded by at least one category, maybe two (from 937 mb down to 952 mb?). Much of the research has been been showing the same conclusion-- hurricanes that are weakening or rapidly unraveling just can't get transport the higher winds down to the surface.

[HurricaneJosh]

You must already have a "gut feeling" answer to your concern, with data that will continue to confirm what you know to be true.

Well, hold on. I don't know anything to be true. I'm honestly just wondering, without an agenda here.

I think that hurricanes making landfall can be broken into 5 broad categories:

1) Rapidly intensifying into landfall (think Charley)

2) Steadily, but gradually, intensifying into landfall (think Hugo)

3) Steady state into landfall (think Frances)

4) Steadily, but gradually, weakening into landfall (think Floyd)

5) Rapidly unraveling into landfall (think Lili)

Given all the data regarding these hurricanes, it's pretty clear that the recent push for more precise estimates given the SMFR and other data sources is yielding to more accurate landfall estimates. Compare Lili to Carmen, for example. Did you see Carmen's radar right before landfall? It's much worse than Katrina's. Also, perusing the land observations, Carmen seems a prime candidate to be downgraded by at least one category, maybe two (from 937 mb down to 952 mb?). Much of the research has been been showing the same conclusion-- hurricanes that are weakening or rapidly unraveling just can't get transport the higher winds down to the surface.

Yeah, I think that Carmen 1974 is a major candidate for downgrading. It seems pretty unlikely it was a Cat 3 in LA-- especially given that craptastic radar shot in the MWR report.

I agree, and I've said it many times here-- that the biggest discovery of the last ten years seems to be the really, really dramatic role that intensity trend has on surface winds. It is huge. It's amazing that this wasn't even considered up until he 1990s. A 960-mb 'cane was a 960-mb 'cane-- the intensity trend, size, and latitude didn't seem to matter when estimating intensity.

But even with examples like Charley-- a prime, Grade-A, rapidly intensifying storm-- why doesn't the HRD wind swath (which is based on actual obs) show anything higher than 110 or maybe 115 kt? And why does the Fujita damage map show peak gusts no higher than what the presumed sustained wind was? Same with Hugo's Fujita map-- it does not reflect 120-kt 1-min winds.

[Superstorm93]

Dual hurricanes in the Atlantic

Even though they are probably at the least desirable positions for many here...

AL, 13, 2012090600, , BEST, 0, 291N, 424W, 65, 990

Hey, who knows.

The NOGAPS and CMC keep 90L off of the SE coast for a few days and make it into a hurricane

[gymengineer]

Yeah, I think that Carmen 1974 is a major candidate for downgrading. It seems pretty unlikely it was a Cat 3 in LA-- especially given that craptastic radar shot in the MWR report.

I agree, and I've said it many times here-- that the biggest discovery of the last ten years seems to be the really, really dramatic role that intensity trend has on surface winds. It is huge. It's amazing that this wasn't even considered up until he 1990s. A 960-mb 'cane was a 960-mb 'cane-- the intensity trend, size, and latitude didn't seem to matter when estimating intensity.

But even with examples like Charley-- a prime, Grade-A, rapidly intensifying storm-- why doesn't the HRD wind swath (which is based on actual obs) show anything higher than 110 or maybe 115 kt? And why does the Fujita damage map show peak gusts no higher than what the presumed sustained wind was? Same with Hugo's Fujita map-- it does not reflect 120-kt 1-min winds.

We've discussed Hugo and the Fujita map on the boards before- don't know if you remember. That was my exact question and therefore wondering if Hugo was indeed really a Cat-4 landfall. Using AOML's reanalysis technique, the answer was "yes." But, the question still remains-- why didn't Hugo cause more apparently impressive wind-damage on land?

[andyhb]

Still GFS fantasy porn in the long range as well.

[Ed Lizard]

I noticed yesterday, I think the from the previous 0Z Euro 10 meter wind fields (which I can see 6 hourly on AccuWx PPV with "Grand Banks" selected when Euro was showing a Nova Scotia hit) that a global with a decent resolution like the Euro has a huge gradient of winds right along the coast, from >75 knots to 45 to 50 knots. This can be seen on many GFDL runs, where the model shows hurricane force winds only over the water.

When people talk about frictional convergence "tightening up" a storms circulation, they are indirectly stating winds over land slow significantly as compared to winds over water. Note latest GFDL with a 50 knot wind barb on the coast, and perhaps a tenth of a degree inland, winds are 20 to 30 knots. (I assume a full flag is 50 knots, but if it is 25 m/s, it winds up being almost the same). I'd suspect, at least for sustained winds, hurricane force winds in a Cat 1 or Cat 2 don't get very far inland, and hurricane type wind damage inland (thinking Hugo and the inland city of Charlotte) even from major hurricanes may be more the product of gusts than sustained hurricane winds.

[Ed Lizard]

Still GFS fantasy porn in the long range as well.

I have decided that the GFS post truncation, while worthless for anything resembling 'precision' guidance (but then again, how precise is the 8 day GFS?) isn't worthless for trends. It becomes almost an extra ensemble member running at lower resolution.

During the mid to late July 'season cancel' season, the GFS and the GEFS would show little or nothing in the Atlantic. Most runs would have nothing, including the ensembles (using 1004 mb as a discriminator), and that started to change as August got busier. GFS did predict some AEWs to really go to town and come West, and that didn't always verify. I believe Kirk was an AEW that was advertised as being a potential storm of the season, and drifted Northwest without developing immediately.

Fantasy range GFS and ensembles have been insistent on something roughly timed to match the 74th anniversary of 1938 on several runs during the recent days. Instead of getting too excited, perhaps one can take some hope that the model is persistent, even beyond the resolution truncation. Speaking of, the 18Z GFS op at 192 hours is West and South of most of the 18Z ensemble members, perhaps higher resolution results in a model forecast track that will be closer to the US (as the 18Z ensembles are mostly fish at 372 hours)

[Ground Scouring]

Did you see my post earlier today? I am wondering if the wind speeds for the whole SS scale need to be revised downward to more accurately reflect what's observed on the ground.

As you and I have noticed, an actual 1-min/10-m wind reading of 85 kt from an official land station in a landfalling hurricane always seems so nuclear-- even though this barely qualifies as Cat 2.

I think that much of the problem can be attributed to the fact that, especially over the last few years, new technologies such as SFMR and recent research on convective trends have shown that the line between representative and transient winds--i.e., between what, exactly, constitutes representative and small-scale winds--is much murkier than once thought. For example, in Jeanne 2004, as reconnaissance penetrated the storm just before FL landfall, the aircraft at 1429Z/25 September recorded 114 kt at 700 mb, according to the NHC report here. Because Jeanne was then deepening steadily from 957 to 952 mb during this period, the NHC used the 90% reduction factor, resulting in a surface wind of 102.6 kt, or ≈105 kt. But a look at the wind-based time series shows that at least the AFWA satellite estimates during this time period were closer to 100 rather than 105 kt--or fully 20-30 kt below those of the TAFB and SAB estimates. The discrepancy is fully relevant because, as you probably know, the satellite presentation of Jeanne at landfall was not outstanding for a 105-kt hurricane; while the eye was warm, it was neither as warm nor as clear as in other intensifying majors, even ones with much smaller eyes like Marilyn 1995 or Omar 2008. Also, there was clearly dry-air intrusion occurring in the southern quadrant, as in this image (note the warmer temperatures just south of the intense convection south of the eye) and radar imagery. All this is relevant because the gridded wind analysis only shows a 90-kt wind contour as well as a rather asymmetric wind structure for an intensifying system, even one that is interacting with land.

Compare the Jeanne analysis with the ones for Andrew 1992 (and two hours after landfall), a rapidly intensifying, small system, and even Camille 1969, a larger and steady-state hurricane at landfall. While both storms were far more intense and smaller than Jeanne was, the main point to be taken is that both storms 1) had a very or fairly symmetric wind structure at or even after landfall and 2) even a steady system like Camille retained very intense winds at the coast, with major hurricane winds of 100 kt even occurring, if the analysis is correct, on the weaker (west) side of the NNW-moving system. While Jeanne was moving faster than Camille and was moving WNW, and thus would have been weaker on the south side, the faster forward speed should not have been expected to create such an asymmetric wind structure with only 60-kt winds over land south of the center--particularly in a system that was deepening steadily at a rather respectable, though not rapid, state (approximately 1 mb/hour). What is clear, however, is that even while deepening, Jeanne 1) exhibited less intense convection than did Andrew (and certainly Camille, based upon Jackson, MS, radar showing a small closed eye after landfall--see the Camille report, PDF p. 7, from the NHC archives) and 2) was experiencing dry-air intrusion, something evidently absent in Andrew and Camille.

Another thing to be mentioned is that I have seen many accounts from chasers who were in Martin and St. Lucie counties, in the immediate region of landfall for both Frances and Jeanne 2004, and even in the eyes of both storms. These chasers noted, in comparing the two storms, is that, even while compensating for the fact that slow-moving Frances cleared out a lot of debris before Jeanne did, the damage from Frances, even near the maximum winds in the N eye wall, seemed worse than that in the same region in Jeanne. While Frances 2004 at 90 kt is officially weaker than Jeanne at landfall gridded analysis for Frances shows a larger inland expanse of 70+ kt north of the eye and, unlike in Jeanne, actually shows a tiny area of 65-kt winds over land near downtown West Palm Beach, whereas such winds in Jeanne never went inland from the coast in Palm Beach County. Also, the overall symmetry of the wind structure is just as good, if not even a bit better in the N quadrant, in Frances as in Jeanne. This is despite the fact that Frances was much larger than Jeanne, was in a steady state at landfall, was surrounded by a weaker pressure gradient (meaning lower winds for the pressure-wind relationship), and was overall lacking a consolidated inner core at landfall--the storm was a bit tilted, or sheared, as it came ashore, due to the same shear that caused it to drop from 125 kt to 90 kt some days earlier. The main difference is that dry air seems to have been lesser of a problem than shear in Frances rather than in Jeanne.

All this makes me wonder whether Jeanne was in fact 100 kt, or even 95 kt, at landfall, while Frances was perhaps just as strong (90-95 kt) but caused much more damage because 1) dry air, being largely absent, did not reduce the conversion factor, so winds transferred more easily to the surface; 2) shear enhanced the gustiness factor, thus causing stronger winds, which were unrecorded (no 100+ kt gusts in Frances, unlike in Jeanne, which produced near-110-kt gusts) because more weather stations, having been unprepared due to minimal tree-trimming before the storm, lost power before the peak conditions came, whereas the storm cleared debris in time for Jeanne, during which fewer stations lost power; and 3) Frances, while larger and slower-moving, with more potential for damage than smaller, more rapidly-moving Jeanne, was really just as strong as its twin a few weeks later.

I also think that dry air and cooler waters have different effects on a storm, so, for instance, a storm like Kirk or Michael this year should not be classified as a weaker storm because its convection is weaker at higher latitudes. Dry air tends to reduce the reduction factor and sometimes decreases gustiness; cooler water, due to the lack of latent heat, may actually exert a smaller effect on the surface winds, particularly if the storm, like Michael, is small and surrounded by a relatively high pressure gradient. (Stability, not dry air, was actually the main thermodynamic factor with Kirk and Michael, and to a relatively limited extant it was, owing to baroclinic factors nearby.) The cool waters actually tend to increase the gustiness factor, particularly above the surface; and if baroclinic/frontal forces are at play, as in the 1938 Long Island Express (which was actually embedded in a fairly tight outer pressure gradient, being wedged between a strong W Atlantic ridge and a highly amplified Appalachian trough), when combined with a storm entering cooler waters while remaining in a tight gradient and accelerating, the results can maintain surface winds and even increase the gustiness factor, even transferring those stronger gusts more effectively to the surface (although elevated, the spectacular 162-kt gust at Blue Hill, MA, in September 1938 is a notable exemplar of this).

To conclude, I would like to end by saying that, in light of these complexities, the recent trend toward discrepancies between pressure and wind--i.e., Isidore 2002, Katrina 2005, Alex 2008, Ike 2008, Isaac 2012, etc.--may merely be an illusion. Obviously, even the Atlantic TC reanalysis is dealing with somewhat limited data prior to the 1950s, so data on RMW, pressure gradient, eye size, etc. may be hard to discern even from several observations many hours apart--especially if no station data were available within 20-40 mi of a landfall location. Let me continue by returning to an old discussion topic of ours: the 1947 Fort Lauderdale hurricane.

Recently, I conducted extensive archival research on the 1947 Category 4 hurricane in South FL and used the research to greatly expand the Wikipedia article on the storm. Note that the lowest pressure in the eye, according to a subsection I authored, was actually 951 mb at Fort Lauderdale, which had calm winds for more than an hour at the time. Based upon this research, the 947 mb at Hillsboro Lighthouse, which was outside the eye and occurred during hurricane-force (!) winds, was likely not reduced to sea level, as the Monthly Weather Review summary claimed. The same Hillsboro anemometer that recorded the 135-kt maximum wind 1) was 115 feet above sea level, near the top of the lighthouse, and 2) actually measured a gust, or 24-second wind, not a 1-minute value (I found the actual Hillsboro observations in the archives at the National Hurricane Center, which listed the value as an “extreme velocity,” a contemporary term usually referring to a 24-second gust. Using a conversion factor of 1.06 provided by the NHC, the 1-minute value was really 127 kt; and as the anemometer was above sea level, a 90% reduction gives a surface wind of 114 kt--just within the low Category 4 range. A newspaper article from Delray Beach after the storm quoted Chief Meterologist Grady Norton in Miami as saying that Delray Beach actually experienced the worst wind damage in the entire storm.

I uploaded this image, with credits to the Delray Beach Historical Society, to Wikipedia, showing the most intense wind damage I could locate in the Delray photo archives. The damage, while severe, actually is only slightly worse than what portions of S FL faced during Wilma--meaning Category 2 winds at most.

An interesting factoid is mentioned in the subset I wrote:

Although it was north of the strongest winds, West Palm Beach was battered by conditions equivalent to a Category 2 hurricane; at Morrison Field, at 1515 UTC on September 17 a three-cup anemometer measured sustained winds from the north-northeast of 100 mph (160 km/h) before losing two of its cups.^[25] In spite of the winds, wind-caused structural damage in the county was generally minor.^[26] At Lake Worth, while most buildings were materially damaged, only 10% were severely so, mostly when asphalt shingles were blown off, and few roofs suffered integral damage.^[9]

West Palm Beach was at least 30 mi from the center at that time, yet according to a newspaper cited it actually recorded sustained Category 2 winds before the peak arrived. Another interesting note is that many coconut palms in West Palm Beach literally snapped during the storm. Such damage, while present, was not as common in the Delray photos. If one presumes Hillsboro had Category 4 winds, and that Delray Beach had maybe low-end Category 2 winds and West Palm Beach slightly higher winds, then perhaps the storm had a double RMW/outer eye wall at landfall, much like that of Katrina 2005 in LA. This fits the description in the first article of a large eye at landfall; note that in a

new reanalysis paper of the 1944-1953 TC seasons (Hagen et al., 2012), p. 4455 has a table listing the U.S. landfalling hurricanes. The 1947 storm was reanalyzed as 115 kt/945 mb at landfall in S FL, with an (inner?) RMW of about 25 mi/20 nm based upon Hillsboro wind data. Since the 1947 storm was so large, and since the research and images I showed did not really show severe, Category-4-type structural damage (i.e., on a Charley 2004- or Andrew 1992-type level), I am really wondering whether the 1947 TC was instead a Category 3 storm, like Jeanne in structure, at landfall, but that we lack sufficient evidence to prove it. How many other reanalyzed TCs like Audrey 1957 present similar complexities?

Hopefully, you will have some time to digest all this! Any comments, anyone?

[Hugo]

We've discussed Hugo and the Fujita map on the boards before- don't know if you remember. That was my exact question and therefore wondering if Hugo was indeed really a Cat-4 landfall. Using AOML's reanalysis technique, the answer was "yes." But, the question still remains-- why didn't Hugo cause more apparently impressive wind-damage on land?

Huh? Hugo clear-cut forested land 25 miles inland, destroyed nearly 7 billion board feet of timber, and recorded a gust of 137 away from the immedaite coast, on the left side of the storm.

I've heard a discussion from several mets who actually surveyed the storm's damage and they all described it as some of the most impressive damage they've ever seen and said it was considerably worse than the damage done five years prior in Tatum, SC, which had been hit by two F-4 tornadoes within a few minutes of each other.

[HurricaneJosh]

Huh? Hugo clear-cut forested land 25 miles inland, destroyed nearly 7 billion board feet of timber, and recorded a gust of 137 away from the immedaite coast, on the left side of the storm.

I've heard a discussion from several mets who actually surveyed the storm's damage and they all described it as some of the most impressive damage they've ever seen and said it was considerably worse than the damage done five years prior in Tatum, SC, which had been hit by two F-4 tornadoes within a few minutes of each other.

OK, but why doesn't the Fujita map reflect this? The issue here isn't that we think Hugo wasn't strong-- it's the discrepancy we see between best-track winds and other data sources. Hugo is cited as one example of this issue.

[HurricaneJosh]

I think that much of the problem can be attributed to the fact that, especially over the last few years, new technologies such as SFMR and recent research on convective trends have shown that the line between representative and transient winds--i.e., between what, exactly, constitutes representative and small-scale winds--is much murkier than once thought. For example, in Jeanne 2004, as reconnaissance penetrated the storm just before FL landfall, the aircraft at 1429Z/25 September recorded 114 kt at 700 mb, according to the NHC report here...

Interesting post, snowflake.

I've often wondered about Jeanne. Like you, I've noticed the huge disconnect between the H*WIND analysis and the official landfall intensity estimate, and I wondered about this. I didn't realize that some people on the ground perceived Frances as stronger--very interesting.

Re: Fort Lauderdale 1947... Reanalysis of that one was tricky due to the really contradictory data, which are surprising given the population density. Given the Hillsboro Lighthouse reading, I am OK with their verdict of 115 kt, although maybe it's a tad generous.

Re: Audrey 1957... I'm convinced it's one of the most overrated 'canes of the mid-century period. Brian Jarvinen's paper from a few years ago is damning-- describing it as a large, loose sloppycane with a huge RMW and max winds of 80 kt. Perhaps he's a bit harsh, but I'd be surprised if it's classed higher than a Cat 2 in reanalysis. The radar signature at landfall was pretty eroded and sorry-looking.

[Scott747]

That said, if Ike was a Cat 4/5 in the Gulf, we'd probably be talking on the level of Katrina in terms of damage or worse (perhaps even regarding deaths).

Ike didn't need to be a 4/5. It only needed to hit down the coast by about 15-20 miles or so (SSPEED report released in 2011 says 30-50) and it would have exceeded Katrina.

Galveston and the West End were so unprepared it isn't funny. Bay side surge would have annihilated the island and it would probably still be rebuilding today. West End would have looked like Bolivar. The Chronicle did a feature back in June with the estimated damage when including the Ship Channel and into Harris County. While probably high it was something like $350 billion.

When accounting for surge it was stronger than both the 1900 and 1915 storms. There is no defense of the SS scale in this particular case. It was the sole reason why so many people remained despite all the warnings.

[jconsor]

Scott - This is very interesting info re: Ike.

Can you provide links to the SSPEED report and the Houston Chronicle article you mentioned?

Thanks!

Ike didn't need to be a 4/5. It only needed to hit down the coast by about 15-20 miles or so (SSPEED report released in 2011 says 30-50) and it would have exceeded Katrina.

Galveston and the West End were so unprepared it isn't funny. Bay side surge would have annihilated the island and it would probably still be rebuilding today. West End would have looked like Bolivar. The Chronicle did a feature back in June with the estimated damage when including the Ship Channel and into Harris County. While probably high it was something like $350 billion.

When accounting for surge it was stronger than both the 1900 and 1915 storms. There is no defense of the SS scale in this particular case. It was the sole reason why so many people remained despite all the warnings.

[CoastalWx]

So you think that's what's behind this?

It can't last forever, but it sure is weird. Even during the mega-lame 1970s and '80s, the USA still managed to get hit by majors in 1970, 1974, 1975, 1979, 1980, 1983, 1985, and 1989.

No I wasn't trying to say that...just stirring up some convo about this. That was one of the things I noticed...it's probably a few factors at least.

[Scott747]

Scott - This is very interesting info re: Ike.

Can you provide links to the SSPEED report and the Houston Chronicle article you mentioned?

Thanks!

SSPEED report - http://www.google.co...wEP0liSVwD35Guw

The book Lessons from Hurricane Ike is out and goes into further detail. Didn't realize it had already been published and have ordered a copy.

Will have to dig up the Chronicle story. The number I mentioned may have been based on the absolute worst case scenario (wind event) and not specifically Ike. Can't remember and thought it may have already been posted here or at our local board.

Was thinking my short rant was in the SS scale thread and not the general Atlantic thread.

Oops.

[Srain]

SSPEED report - http://www.google.co...wEP0liSVwD35Guw

The book Lessons from Hurricane Ike is out and goes into further detail. Didn't realize it had already been published and have ordered a copy.

Will have to dig up the Chronicle story. The number I mentioned may have been based on the absolute worst case scenario (wind event) and not specifically Ike. Can't remember and thought it may have already been posted here or at our local board.

Was thinking my short rant was in the SS scale thread and not the general Atlantic thread.

Oops.

http://www.chron.com/news/houston-texas/article/New-study-highlights-region-s-extreme-wind-3605028.php

[Ed Lizard]

Pre-market trading on Gulf Mandarin becoming Nadine Isaacdottir lower, NHC threatening to canx flight, 40%...

[wxsmwhrms]

Pre-market trading on Gulf Mandarin becoming Nadine Isaacdottir lower, NHC threatening to canx flight, 40%...

Was a little surprised to see the satellite/radar after reading NHC's TWO first. Looks to me like convection is developing closer to the LLC, and the upper level winds on the satellite derived winds actually look more favorable than I expected. It's a small system, but still certainly bears watching. Dry air seems to be the big limiter.

[jconsor]

Certainly the chances of a major hurricane forming late in the hurricane season, much less hitting the U.S., are reduced in El Nino years. However, I found 3 major hurricanes which hit the U.S. and formed later than Sep 13.

1877 (formed 21 Sep) - hit FL panhandle at 100 kt (http://weather.unisys.com/hurricane/atlantic/1877/4/track.gif)

1896 (formed 22 Sep) - hit Apalachee Bay area of FL at 110 kt (http://weather.unisys.com/hurricane/atlantic/1896/4/track.gif)

1941 (former 3 Oct) - hit SE FL at 105 kt (http://weather.unisys.com/hurricane/atlantic/1941/5/track.gif)

Also, two strong cat 2's that were nearly cat 3:

1888 (formed 8 Oct) - hit Apalachee Bay area of FL at 95 kt (http://weather.unisys.com/hurricane/atlantic/1888/7/track.gif)

1899 (formed 26 Oct) - hit near SC/NC border at 95 kt (http://weather.unisys.com/hurricane/atlantic/1899/9/track.gif)

1877, 1888, 1896 and 1899 were all strong El Nino events. 1941 was a weak event.

Here is the JMA 5-month running mean SST series going back to 1868, which can be used to determine Nino years:

ftp://www.coaps.fsu.edu/pub/JMA_SST_Index/jmasst1868-today.filter-5

Furthermore, historical records indicate that no major hurricane that struck the U.S. during El Niño formed later than September 13 (Jeanne 2004). As the pattern this year has favored a much weaker ridge and stronger shear than in September 2004, and as El Niño should shut down activity by the first week of October (thus shutting down the late-season W Caribbean systems in FL), I am 99% confident that the chances of a major hurricane hitting the U.S. are practically 0% this year.

[GaWx]

Certainly the chances of a major hurricane forming late in the hurricane season, much less hitting the U.S., are reduced in El Nino years. However, I found 3 major hurricanes which hit the U.S. and formed later than Sep 13.

1877 (formed 21 Sep) - hit FL panhandle at 100 kt (http://weather.unisy...877/4/track.gif)

1896 (formed 22 Sep) - hit Apalachee Bay area of FL at 110 kt (http://weather.unisy...896/4/track.gif)

1941 (former 3 Oct) - hit SE FL at 105 kt (http://weather.unisy...941/5/track.gif)

Also, two strong cat 2's that were nearly cat 3:

1888 (formed 8 Oct) - hit Apalachee Bay area of FL at 95 kt (http://weather.unisy...888/7/track.gif)

1899 (formed 26 Oct) - hit near SC/NC border at 95 kt (http://weather.unisy...899/9/track.gif)

1877, 1888, 1896 and 1899 were all strong El Nino events. 1941 was a weak event.

Here is the JMA 5-month running mean SST series going back to 1868, which can be used to determine Nino years:

ftp://www.coaps.fsu.edu/pub/JMA_SST_Index/jmasst1868-today.filter-5

Good info. Note also that none of them were officially "CV" storms (per my def. which is that they must first become a TD+ east of 50W and S of 20N per the official track). Of course, after 9/11, the chances of a CV storm first forming as a TD+ and then making it to the CONUS goes down markedly for any ENSO (only 5 did just that back to 1851).

Exact dates of FORMATION (TD+) for the 47 1851-2010 CV storms that later hit the U.S including Earl of 2010 and Emily of 2005:

7/5, 7/11, 7/15, 7/31, 8/3, 8/3, 8/5, 8/7, 8/7, 8/15, 8/15, 8/16, 8/16, 8/17, 8/17, 8/18, 8/19, 8/20, 8/20, 8/21,8/23, 8/23, 8/25, 8/25, 8/27, 8/28, 8/28, 8/29, 8/29, 9/1, 9/2, 9/3, 9/4, 9/6, 9/6, 9/7, 9/8, 9/10, 9/10, 9/10, 9/10, 9/11, 9/15, 9/16, 9/21, 9/21, 9/25

So, 156 years of history clearly show a sharp peak on 9/10 followed by a plunge in frequency. Keep in mind that these are dates of FORMATION, not hit dates.

[wxmx]

Josh, the main difference that I can see in the Atlantic since the 2005 season is the development of

a band of 850 mb wind anomalies over the Tropical Atlantic. Without a study, it's tough to know

the cause or how much impact it may or may not be having on tropical cyclone activity.

Westerly anomalies in the low level winds in the MDR, to my understanding, promotes a higher number of tropical cyclones ... they are too far to the east away from land, probably aiding cyclogenesis in fish-prone areas.

[Srain]

Was a little surprised to see the satellite/radar after reading NHC's TWO first. Looks to me like convection is developing closer to the LLC, and the upper level winds on the satellite derived winds actually look more favorable than I expected. It's a small system, but still certainly bears watching. Dry air seems to be the big limiter.

I believe there is a small but brief window tonight/tomorrow as shear decreases and conditions become a bit more favorable for development. We will see.