Discussion of Intense Tropical Cyclones

[euro6208]

Haiyan may not have a central pressure as low as many estimate, but the winds were powerful---more than the JTWC/JMA have given officially. I reckon 890-905 hPa at peak with winds of 180-190 kts

Why even use JMA's pressure for these type of strong typhoons? They are awfully high and only rounded off to the nearest 5's.

[xtyphooncyclonex]

Haiyan may not have a central pressure as low as many estimate, but the winds were powerful---more than the JTWC/JMA have given officially. I reckon 890-905 hPa at peak with winds of 180-190 kts

Why even use JMA's pressure for these type of strong typhoons? They are awfully high and only rounded off to the nearest 5's.

Haiyan's central pressure is supposedly high relative to its winds, compared to other storms with a similar intensity (Tip, Patricia). Haiyan tracked over an area of high background pressures and was steered by a powerful anticyclone to its north. It was a low-latitude compact storm, attaining peak intensity close to 10°N.

JMA's pressure estimate, though I disagree with them a lot, may be just right for Haiyan. The winds may have to be bumped up following studies and how flawed their scale is. Additionally, the JTWC gave the exact same pressure estimate at its peak. The Kubota, Cayanan et al paper states that Guiuan may have experienced 360 km/h wind gusts and a minimum pressure of 910 mb during the passage of Haiyan. Through iCyclone's observations, it can be concluded that the barometric pressure in Tacloban during Haiyan's closest approach (roughly 20 km south) never dipped below 950 mb.

Haiyan is perhaps the strongest storm globally in terms of wind speeds alone, as evidenced by actual observations and research papers. Haiyan's central pressure may not be as deep as what many of us think, but its winds may be well stronger.

[euro6208]

Haiyan may not have a central pressure as low as many estimate, but the winds were powerful---more than the JTWC/JMA have given officially. I reckon 890-905 hPa at peak with winds of 180-190 kts

Why even use JMA's pressure for these type of strong typhoons? They are awfully high and only rounded off to the nearest 5's.

Haiyan's central pressure is supposedly high relative to its winds, compared to other storms with a similar intensity (Tip, Patricia). Haiyan tracked over an area of high background pressures and was steered by a powerful anticyclone to its north. It was a low-latitude compact storm, attaining peak intensity close to 10°N.

JMA's pressure estimate, though I disagree with them a lot, may be just right for Haiyan. The winds may have to be bumped up following studies and how flawed their scale is. Additionally, the JTWC gave the exact same pressure estimate at its peak. The Kubota, Cayanan et al paper states that Guiuan may have experienced 360 km/h wind gusts and a minimum pressure of 910 mb during the passage of Haiyan. Through iCyclone's observations, the barometric pressure in Tacloban during Haiyan's closest approach (roughly 20 km south) never dipped below 950 mb.

Haiyan is perhaps the strongest storm globally in terms of wind speeds alone, as evidenced by actual observations and research papers. Haiyan's central pressure may not be as deep as what many of us think, but its winds may be well stronger.

Yup it was a really compact storm. Tacloban never got into the eye hence the high reading.

Amazing. Haiyan and Meranti are tied for strongest TC on landfall (170 knots) in world history just 3 years apart. Of course this is just based on satellite. These 2 had better structure than most that had recon.

[1900hurricane]

Hoarau sure has been busy lately. Using the 910 mb reading from Guiuan and extrapolating the pressure gradient from systems like Megi '10 and Patricia '15, he estimates a pressure near 860 mb from Haiyan '13!

 https://twitter.com/Cyclonebiskit/status/926135943509274624

[euro6208]

I won't be surprised. No way Tip is still the strongest with recon out since 1987. I bet a bunch of typhoons follow Haiyan maybe some cyclones and hurricanes too but it be a parade of typhoons on the list for strongest.

[Ptarmigan]

Interesting to think that Super Typhoon Haiyan could be more intense than previously thought.

[Ptarmigan]

Speaking of intense tropical cyclones, I would like to add to the discussion some pre-satellite Atlantic storms for which there is ample (though far from ideal) observational coverage: the twin Indianola hurricanes in Texas (1875 and '86), the twin Galveston hurricanes (1900 and '15), the 1926 Miami hurricane, Hurricane San Felipe Segundo / Okeechobee (1928), the 1935 Labor Day hurricane, the 1938 (New England) and 1944 (Great Atlantic) hurricanes, and Donna (1960). A recent study (see the appendix) found that the 1875 hurricane may have had a pressure as low as 928 mb as it neared Texas, apparently based on newly uncovered ship reports as well as storm-surge data. A storm surge of fifteen feet affected portions of the Texas coastline in and near Indianola. The 1886 hurricane produced a similarly high surge and generated a pressure of 965 mb at San Antonio, well inland from the barrier islands. A study by a storm-surge specialist estimated that the 1915 hurricane was a strong Category 4 cyclone with a 930-mb pressure at landfall in Texas that produced a potential storm-surge height of at least thirty feet, though the reanalysis project found the system to be 115 knots (940 mb) at landfall, making it a low-end Category 4 cyclone. The 1926 hurricane may have briefly been a Category 5 cyclone over the Bahamas, given the damage and sparseness of observations as well as later data from South Florida. The 1928 cyclone definitely appears to have been a solid Category 5 over Puerto Rico, based on observations; it may well have been stronger than 120 knots over Guadeloupe. The 1935 Labor Day hurricane was almost certainly stronger than the 160 knots it received in the reanalysis, based on the tiny RMW, rapid deepening, and high background pressures, given its proximity to a subtropical ridge. Ship reports at sea (not land data) strongly suggest that the 1938 and 1944 hurricanes may well have exceeded the minimum Category-5 threshold at their peaks; one study assessed the central pressure to be 909 mb in the latter storm to the northeast of the Bahamas. Donna's radar presentation in the Keys, with its concentric, closed, intense eyewall, was extremely impressive, even when the crudeness of the technology in 1960 is considered.

I am not surprised that the 1935 Labor Day Hurricane has over 160 knots. I would not be surprised if it was 185 knots.

The 1928 Okeechobee Hurricane was a large hurricane I read.

I am not surprised that the 1875 and 1886 Indianola Hurricane were intense. I read that the 1886 was a very large hurricane.

The 1915 Texas Hurricane was large as well from re-analysis.
http://www.aoml.noaa.gov/hrd/Landsea/reanal_1911-20.pdf

[Alyono]

Hoarau sure has been busy lately. Using the 910 mb reading from Guiuan and extrapolating the pressure gradient from systems like Megi '10 and Patricia '15, he estimates a pressure near 860 mb from Haiyan '13!

 https://twitter.com/Cyclonebiskit/status/926135943509274624

probably not. In fact, I suspect it had a HIGHER pressure than Megi, though since the ridge was stronger north of the system, and it was moving faster, it had a significantly higher wind speed than Megi. Probably in the 895mb range in terms of pressure, but 185-190 kt sustained winds

[Alyono]

a TC that likely had significantly higher than reported winds was Isabel at its peak. They were using the 90 percent rule at its peak, when it is more likely flight level winds were equal to the surface winds. It probably was in the 160-165 kt range at peak

[NotoSans]

The major problem of the study is that the centre cannot be precisely located using microwave imagery. If you are making position estimates corrected to the nearest 0.1 degree, microwave imagery would be a good tool. Yet, when it comes to situations in which every kilometre matters a lot, using microwave imagery is not enough; otherwise, there would be a very large margin of error.

[euro6208]

Amazing to read this thread again.

So it took out from nowhere and only hurricane below 900mb from the EPAC and closest to any WPAC typhoons to make this thread because it had recon. Just imagine all of those unnoticed and low biased typhoons because it has to follow dvorak. Recon proved it is more reliable than satellite for really strong systems. What satellite sees as really strong...dvorak and cold convection, they must be high and look very strong...is actually the opposite. As seen in this year's atlantic hurricane season.

Comparing Patricia (recon) to the most powerful typhoons including Haiyan (Satellite) and saying it is 2 mb weaker than the most powerful TC in history...Obsolete STY Tip from 1979...when recon ended in 1987...is just disgusting. Oh that's just the pressure. How much more with the winds.

[xtyphooncyclonex]

Amazing to read this thread again.

So it took out from nowhere and only hurricane below 900mb from the EPAC and closest to any WPAC typhoons to make this thread because it had recon. Just imagine all of those unnoticed and low biased typhoons because it has to follow dvorak. Recon proved it is more reliable than satellite for really strong systems. What satellite sees as really strong...dvorak and cold convection, they must be high and look very strong...is actually the opposite. As seen in this year's atlantic hurricane season.

Comparing Patricia (recon) to the most powerful typhoons including Haiyan (Satellite) and saying it is 2 mb weaker than the most powerful TC in history...Obsolete STY Tip from 1979...when recon ended in 1987...is just disgusting. Oh that's just the pressure. How much more with the winds.

Isn't it disgusting to tell the truth that Haiyan's pressure was much higher than Megi, let alone Patricia?

[CrazyC83]

It's always interesting to look back - and only God knows what Recon would have found if it went into Haiyan. I would estimate the peak intensity to be 185 kt, but +/- 10 kt at least.

Regarding Isabel, good point - also remember that the peak intensity was likely before Recon as that is when Dvorak peaked so it is certainly possible it was stronger on September 11-12, 2003. I do think the latter part of the cat 5 period for Isabel it may have been overestimated due to its large eye and annular characteristics.

[CrazyC83]

Hoarau sure has been busy lately. Using the 910 mb reading from Guiuan and extrapolating the pressure gradient from systems like Megi '10 and Patricia '15, he estimates a pressure near 860 mb from Haiyan '13!

 https://twitter.com/Cyclonebiskit/status/926135943509274624

probably not. In fact, I suspect it had a HIGHER pressure than Megi, though since the ridge was stronger north of the system, and it was moving faster, it had a significantly higher wind speed than Megi. Probably in the 895mb range in terms of pressure, but 185-190 kt sustained winds

For an unpublished school report, I used the storm chaser data to estimate the central pressure at landfall, and came up with 897mb at that time. While it weakened some in the last few hours before that landfall, there's no way it dropped 20 or more millibars.

[NotoSans]

JMA has actually been conducting reanalysis on Typhoon Haiyan using Doppler radar data. The related documents are given below. It is said in the second document that the paper regarding the reanalysis will be submitted by the end of 2017, but as far as I know the paper has yet to be published.

https://confit.atlas.jp/guide/event-img ... df?type=in
http://www.typhooncommittee.org/49th/Do ... ionJMA.pdf

[tatertawt24]

a TC that likely had significantly higher than reported winds was Isabel at its peak. They were using the 90 percent rule at its peak, when it is more likely flight level winds were equal to the surface winds. It probably was in the 160-165 kt range at peak

Isabel had some sort of outrageous 230mph gust measured by recon on the 13th, probably from one of the dropsondes getting caught in one of the mesovorts. It wouldn't surprise me if it was at least a little bit stronger than the official 165mph peak.

[euro6208]

Some great read from Wunderground.

Possible New World Record for Lowest Barometric Pressure: 860 mb?

https://www.wunderground.com/cat6/possible-new-world-record-lowest-barometric-pressure-860-mb



This picture speaks for itself. We have tons of typhoons peaking at extraordinary levels then after 1987 when recon stopped, they just suddenly disappeared as if our typhoons got alot weaker. Maybe global cooling? Satellite is screwed and the masses are led to believe that these estimation for post 1987 are real.

[Alyono]

a TC that likely had significantly higher than reported winds was Isabel at its peak. They were using the 90 percent rule at its peak, when it is more likely flight level winds were equal to the surface winds. It probably was in the 160-165 kt range at peak

Isabel had some sort of outrageous 230mph gust measured by recon on the 13th, probably from one of the dropsondes getting caught in one of the mesovorts. It wouldn't surprise me if it was at least a little bit stronger than the official 165mph peak.

or maybe it was legit and Isabel was closer to 170 kts at peak

[euro6208]

Super Typhoon Nancy in 1961 with recon confirmed 185 knots likely would have been the first megastorm in history.

Skeptics were like. Oh measurements and estimations of wind speeds from the 1940s to 1960s were too excessive then recon confirmed Patricia came...They've been happening for a long long time.



WP, 18, 1961090712, , BEST, 0, 88N, 1643E, 50
WP, 18, 1961090718, , BEST, 0, 88N, 1632E, 60
WP, 18, 1961090800, , BEST, 0, 88N, 1618E, 90
WP, 18, 1961090806, , BEST, 0, 89N, 1601E, 105
WP, 18, 1961090812, , BEST, 0, 89N, 1584E, 115
WP, 18, 1961090818, , BEST, 0, 90N, 1568E, 125
WP, 18, 1961090900, , BEST, 0, 91N, 1551E, 135
WP, 18, 1961090906, , BEST, 0, 93N, 1533E, 140
WP, 18, 1961090912, , BEST, 0, 96N, 1517E, 150
WP, 18, 1961090918, , BEST, 0, 100N, 1499E, 150
WP, 18, 1961091000, , BEST, 0, 105N, 1483E, 160
WP, 18, 1961091006, , BEST, 0, 110N, 1467E, 165
WP, 18, 1961091012, , BEST, 0, 115N, 1452E, 175
WP, 18, 1961091018, , BEST, 0, 120N, 1440E, 175
WP, 18, 1961091100, , BEST, 0, 126N, 1428E, 180
WP, 18, 1961091106, , BEST, 0, 132N, 1414E, 180
WP, 18, 1961091112, , BEST, 0, 140N, 1401E, 180
WP, 18, 1961091118, , BEST, 0, 148N, 1388E, 180
WP, 18, 1961091200, , BEST, 0, 155N, 1375E, 185
WP, 18, 1961091206, , BEST, 0, 162N, 1361E, 180
WP, 18, 1961091212, , BEST, 0, 170N, 1349E, 180
WP, 18, 1961091218, , BEST, 0, 177N, 1337E, 170
WP, 18, 1961091300, , BEST, 0, 184N, 1323E, 170
WP, 18, 1961091306, , BEST, 0, 194N, 1313E, 160
WP, 18, 1961091312, , BEST, 0, 206N, 1306E, 160
WP, 18, 1961091318, , BEST, 0, 219N, 1299E, 150
WP, 18, 1961091400, , BEST, 0, 232N, 1294E, 150
WP, 18, 1961091406, , BEST, 0, 246N, 1291E, 140
WP, 18, 1961091412, , BEST, 0, 259N, 1289E, 140
WP, 18, 1961091418, , BEST, 0, 272N, 1291E, 130
WP, 18, 1961091500, , BEST, 0, 282N, 1293E, 125
WP, 18, 1961091506, , BEST, 0, 291N, 1300E, 120
WP, 18, 1961091512, , BEST, 0, 299N, 1311E, 110
WP, 18, 1961091518, , BEST, 0, 312N, 1323E, 110
WP, 18, 1961091600, , BEST, 0, 331N, 1340E, 90
WP, 18, 1961091606, , BEST, 0, 355N, 1361E, 70
WP, 18, 1961091612, , BEST, 0, 393N, 1392E, 65
WP, 18, 1961091618, , BEST, 0, 446N, 1418E, 65
WP, 18, 1961091700, , BEST, 0, 485N, 1444E, 60, 0, XX, 0, , 0, 0, 0, 0,
WP, 18, 1961091706, , BEST, 0, 507N, 1469E, 50, 0, XX, 0, , 0, 0, 0, 0,
WP, 18, 1961091712, , BEST, 0, 550N, 1525E, 40

http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/atcr/1961atcr.pdf

[xtyphooncyclonex]

Super Typhoon Nancy in 1961 with recon confirmed 185 knots likely would have been the first megastorm in history.

Skeptics were like. Oh measurements and estimations of wind speeds from the 1940s to 1960s were too excessive then recon confirmed Patricia came...They've been happening for a long long time.

I have an important question for you: In your own world, would there ever be an intense hurricane that would be overestimated? Is everything underestimated in the Western Pacific? Why is nearly every typhoon with an eye a super typhoon, or those with pinholes stronger or as strong as Wilma?

Hurricanes and typhoons can both be underestimated and overestimated. Let that sink in. No need to be so cocky about everything being stronger than initially thought. One hurricane was Hurricane Dog. At first, it was estimated to be 160 kts. Reanalysis shows that it was actually 125 kts. Truth is, hurricanes and tropical cyclones in general are getting stronger as time passes by. It is storms in the past that tend to be overestimated and those in the present tend to be otherwise. Yes, more storms now may be underestimated but that does not mean everything has to be stronger than what we think. By the way, Katrina made us learn that wind intensity and categories aren't everything. You don't need every storm to be a category 5 to have so much destruction and wreak havoc. Stop -removed- to make every intense storm a category 5.

And btw, you posted this for the nth time.