Ground Scouring

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  1. The CanSIPS, NMME, and CFSv2 models are suggesting that the current +PDO, which has persisted for two years, will continue through the fall (and perhaps early winter) of 2016. Such a long +PDO stretch without a single monthly negative reading would be unprecedented since the early 1940s. We've already seen 25 consecutive months of positive values. Is there any climate feedback that could favor more frequent/intense or long-lived +PDO cycles in a warmer world? Obviously, they've occurred many times on (and off) record.

     

    http://research.jisao.washington.edu/pdo/PDO.latest


  2. Fat lady is singing. At least we got some rain in NorCal, SoCal barely got anything, mostly in December. The background state of a drier west coast (could be caused by climate change, PDO, NAO, or other external factors) has overwhelmed the Nino signal.

     

    CA has been getting drier over the past few decades. Hadley cell expansion? Can't see that changing anytime soon. This is the new norm, and CA has to find new ways of getting water for its ever expanding population soon.

    Most likely the warming of the Pacific/Indian basins and the attendant Hadley expansion have been the long-term climatic signals favoring drier conditions in CA. The overuse of local resources is worrisome in light of the overall changes in the global climate system. At some point, conditions and overpopulation could make parts of the state uninhabitable, barring technological evolution, which is always likely to help people cope with change. The question is whether there is some point at which even larger sacrifices besides conservation will need to be made.


  3. Long-range guidance (CanSIPS, NMME, CFSv2, etc.) has been fairly consistent in depicting a 2011-type summertime pattern at 500 mb, with a mean ridge over the southern High Plains and a weakness over the western Atlantic. That type of pattern would be mostly very unfavorable for storms to hit the United States, unless homegrown MCV-type/frontal development were to occur in the northern Gulf of Mexico. Otherwise, storms approaching from the MDR would likely curve out to sea or continue into the Caribbean, where westerly shear may be elevated thanks to the tenacious +PDO (shown by all guidance for ASO '16), with attendant warmer-than-average SST projected off the Pacific Northwest and Baja California. We'll likely have a slightly-above-average season with few, if any, U.S. landfalls.

     

    2011 tracks


  4. Yeah I think immediately in DC people will disappointed unless this band gets here in a hurry and does serious work, but in the end it will still be a great event.

    Honestly, by most people's standards this won't end up as historic, simply because the heaviest +SN is out in the boondocks of far northern VA, eastern WV, and western MD. Technically, it's still a HECS, but considering how those areas have seen many similar events, it's not as historic as similar totals would be farther east and south. After all, the areas most affected are along the Appalachians...


  5. Models continue to advertise a potentially significant threat around 30 Jan–1 Feb, with the 12Z deterministic ECMWF and the 12Z EPS showing one of the warmest low-level air masses since 26 Dec 2015 (the date of the Garland, TX, EF4 tornado) over the southern High Plains for multiple days. In fact, even the EPS mean shows 15°C 850-mb temperatures reaching as far north as the TX/OK panhandles on at least two of the days that I mentioned. One important key is the relatively low amplitude of the upcoming pattern, with its lack of significant cold intrusions, which not only may prevent heights from rising too much ahead of any ejecting disturbance, but also allows southwesterly low-level flow to advect richer instability (as well as a noticeable if not strong elevated mixed layer, which is surprising given the subtropical jet) north from the Mexican plateau. The tongue of greatest instability is likely to be at least a bit narrower than projected at this point, but the fact that we are talking about EMLs and a potentially significant southern High Plains threat in a potent El Niño says a lot.

     

    For reference:

     

    0KsFC23.gif


  6. Both the EPS and the GEFS are signaling a major long-range pattern shift toward the the end of January and the first week of February (especially around 28 Jan–1 Feb), with a restrengthening of the polar vortex and at least a transient +NAO/–EPO/–PNA period taking hold. Even at this range, models are indicating that the polar jet will take over as the dominant stream with strong hints of multiple shortwave impulses intruding into the Pacific Northwest, likely inducing lee cyclogenesis east of the Rockies. Details regarding ejection and overall evolution are obviously too early to ascertain, but the overall trend toward a more zonal look/longer wavelengths favors a Southeast ridge with likely favorable moisture vectors out of the Caribbean, setting up a potentially decent return flow over the southern High Plains for a few days in advance of any potential ejecting disturbance. There aren't many analogs from strong El Niño events since 1950, but an interesting one is 26 Feb 1958, which was somewhat similar synoptic-wise and featured several significant tornadoes across LA and MS. An interesting difference is that this case may also extend the opportunity for severe weather to the southern High Plains.

     

    NMgEulw.gif


  7. That Lee County, Florida storm wasn't warned for the longest time. Here's the radar imagery:

    attachicon.gifimage.png

    attachicon.gifimage.png

    This area really needs an extra radar to fill in holes, considering the demographic vulnerabilities of the area and much of FL (mobile homes, densely packed subdivisions and apartments, elderly snowbirds, etc.). We've already seen two fatalities in a mobile home from that "large and extremely dangerous" tornado near Duette in Manatee County. Seven people were in the home when the tornado hit and did not take any precautions whatsoever. There are numerous mobile homes in the Fort Myers/Cape Coral area as well and is a potential disaster waiting to happen, especially with paltry radar coverage.


  8. Alex became only the 3rd Atlantic hurricane on record in January. Alex is also the strongest such hurricane on record with maximum sustained winds of 75 knots. An unnamed hurricane in January 1938 and Alice (1955) had peak maximum sustained winds of 70 knots.

    Don, I'd kindly wish to correct you. Reanalysis has upgraded ALICE's peak winds in January to 80 kt on 2 January, making ALEX the second strongest. ALEX also happens to be the second most northeasterly hurricane on record in the basin, behind only VINCE in 2005.

     

    Best wishes!


  9. NHC will initiate advisories on Subtropical Storm Alex, located over the far eastern Atlantic Ocean, at 4 pm EST/2100 UTC.

     

    From the official NHC site (Special Message). This would likely mark the first coincidence (simultaneous occurrence) of two January tropical cyclones in the Atlantic and Central Pacific, respectively, and definitely marks the first January Atlantic TC since 1978.


  10. Surface analyses by TAFB at 12Z indicate that the surrounding air mass has sufficiently modified so that 90L has practically shed its cold front. The system is more symmetric than previously, there are hints of mid-level anticyclonic flow as the cold-core trough shears out. Satellite imagery shows a steady improvement in organization, with a concentrated area of convection and even a formative eye, though the structure is still a bit tilted overall. The system actually looks to be transitioning straight to tropical status without an intermediate stage, though the switch will only last about a day or so, as the system is already curving northeast and leaving warmer SST (it is already over an area with below-average anomalies thus far). Nevertheless, the system looks to have winds approaching hurricane status at this time (55-60 kt). It seems likely to become a hurricane-strength system shortly. Maybe it will be upgraded in a post-seasonal analysis, making it one of only two Atlantic cyclones to reach hurricane status in January. Amazing...

     

    g69872M.jpg


  11. What am I missing? Those maps look like a +AMO to me...very positive for the CFS. The tropical Pacific looks less favorable for the Atlantic in the CFS but it's the JJA period vs August only in CanSIPS, and is clearly in a cooling trend.

    Compared to 1997-2012, the 2013-15 period shows clear cooling trends in the deep tropics, especially near the Caribbean, along with noted cooling southeast of Greenland and warming off the East Coast/Northeastern U.S. According to Dr. Phil Klotzbach, these trends signal a weakening or reversal of the AMOC/+AMO due in part to solar activity, the NAO, and climate change. The CFSv2 (see Levi Cowan's site for the monthly data) and CanSIPS show the bulk of the warmest anomalies near the Eastern Seaboard with relatively cooler but still positive anomalies in the MDR, though the CFS shows below-average SST in the Caribbean by September. I haven't seen anyone suggesting that the AMO will be favorable this upcoming season, given that it has to recover significantly between now and peak season.

     

    Here you can see the influence of the +NAO trend:

     

    vpGbcGG.png

     

    Note the impact on SST anomalies:

    K34cNm0.jpg


  12. I know that they're both long-range outlooks, but both CanSIPS and the CFSv2 are showing a rather –AMO by peak season (September), with cooler-than-average anomalies in the North Atlantic and the warmest anomalies concentrated along the Eastern Seaboard/off the Northeastern U.S. This is consistent with a weakened AMOC. Of course, there are some major differences, with CanSIPS showing a warmer Caribbean and a cool eastern Pacific with a strong La Niña ongoing, while the CFSv2 is quite the opposite and overall more unfavorable for the Atlantic (–AMO plus enhanced shear via EPAC forcing). The December '15 ECMWF long-range forecast doesn't extend beyond June, but also shows a similar SST configuration in the Atlantic: warmest anomalies off the East Coast, relatively cooler anomalies in the MDR, below-average anomalies in the North Atlantic. So the model consensus seems to be that the AMO won't be particularly favorable this upcoming season.

     

    Overall, how much the AMO rebounds from its current low will depend in part on the state of the NAO in JFM. We would need a mean –NAO this month and a strongly negative –NAO in February/March to really allow a substantial weakening of the trades and a big warm-up in the MDR. Down the line, the MJO, the rate of decay of El Niño, and the state of the IOD will also be important, especially if the AMO does not recover. Another thing to keep in mind is that a –AMO correlates with a weakened subtropical high and more development outside the deep tropics, meaning that storms, when available, are much more likely to curve out to sea, which would mean that the U.S. would likely go yet another year without a major (and possibly any hurricane) landfall. If we are indeed in an altered climate regime, then we could go another decade or more without any major U.S. landfalls, given that the current global climate regime is something that we have not observed in modern times.

     

    Overall, my sense is that the Atlantic may be dead for the foreseeable future, with the mean activity shifting over into the Pacific, given the rate of SST warming over there and the likelihood for more active MJO periods.


  13. Hey, this is really interesting! Do you have a link or some other form of reference that you could send me? I would love to see it.

    The reference is the book Gladesmen: Gator Hunters, Moonshiners, and Skiffers by Glen Simmons and Laura Ogden (Gainesville: University Press of Florida, 1998). Chapter 4, "Flamingo and the Cape" (pp. 122-163), contains a number of images taken within a few years of the 1935 hurricane's passage over Cape Sable, now within the southwestern part of Everglades National Park on the South Florida mainland. Pages 126, 145, and 157 contain images showing how the 1935 hurricane literally stripped bare and even partly debarked black mangrove forests in the area.


  14. Josh,

     

    You've had so many fantastic intercepts recently in the Pacific (both east and west) that I've followed heartily...but don't you wish that some of that activity will filter closer to home? The lack of a major U.S. landfall since 2005 has really added manifold costs to your far-flung chases. Every once in a while, you need a little extra geographical variety. Plus, you've chased a lot of compact, intense cyclones recently...don't you wish for a big but intense major closer to the U.S.?

     

    We haven't had a large-sized Category 4/5 landfall in the U.S. since HUGO 1989. On this matter, the standpoints of preparedness and storm chasing converge nicely, for such a long period--more than 26 years--without a sprawling, extremely strong landfall (by maximum sustained winds of ≥113 kt) also gives coastal communities a false sense of security, especially given fading memories of the human mistakes made before, during, and after such storms like KATRINA, a large storm that still degraded significantly prior to landfall.

     

    A lot of people thought that existing infrastructure and emergency readiness could handle a storm like KATRINA (and even Cat.-1 winds in WILMA in Southeast FL)...yet we ended up with 1,836 dead, ignored evacuation orders, poor maintenance of infrastructure, and a dismal response on the local, state, and federal levels. South FL, especially its condos, fared surprisingly badly in Cat.-1 WILMA. Given how no one left Key West prior to WILMA, and how many officials in Galveston dismissed IKE, you have to wonder if we are giving ourselves too much credit. We were just lucky that we didn't have worst-case scenarios.

     

    Ultimately, going too long without a major hurricane of HUGO-type proportions allows societies to continue to tolerate corrupt politics, poor communications, bad infrastructure, and complacency that put communities at risk. Perhaps we should not assume that, say, a repeat of the 1926 Miami hurricane--a very large, 125-kt/930-mb 'cane (read the Wikipedia article that I expanded)--would not result in hundreds of deaths, even in South FL, especially given the degraded Okeechobee dike.

     

    So, if people blame you for eagerly anticipating major landfalls as chase subjects, you should also remind them that hurricanes serve a larger Darwinian purpose in weeding out faulty logic, poor policies, misplaced societal priorities, and the body of people who just won't listen and get out as needed. You actually NEED big storms (and other, more human-made catastrophes) to occur on a rather frequent basis for societies to learn from error, advance, and adapt for the better. Plus, they're essential to scientific analysis that improves our knowledge of tropical cyclones and their dynamics.

     

    I'm sorry if I went a bit off topic, but this just reflects my appreciation and admiration for your scientifically invaluable work. Keep it up, and Happy Thanksgiving! :)


  15. I got a call today from a NWS met who was just in Mexico surveying the landfall zone with a ground team. (He called me to thank me for my report, which they found helpful.) They found some very intense tree damage near the open coast, and I'm eager to see these pics, as they'll be more indicative of the max winds than what we had a couple of miles inland.

    Along with the wind-testing of the anemometer at the Cuixmala biological station, this survey--and your data!--should be very useful in gauging the true strength of PATRICIA at landfall. I'm very gratified to see that this historic event is being (and has been!) documented to the best of everyone's ability. Hopefully, the data will culminate in raw material suited to in-depth studies, aside from that contained in the official, post-seasonal report. I would also love to see Mexico make investments in new radar sites.


  16. Here's my comment:  Any list like this that leaves off Ivan in Grand Cayman is a crappy list.

    The wind damage on Grand Cayman in Ivan, while severe, does not compare to that in the other cases that I listed. Most of the trees stripped bare on the island were deciduous trees that shed leaves readily, such as Australian pines (Casuarina) and Terminalia trees. Many other trees seem to have been uprooted and stripped by storm surge rather than wind. Moreover, I haven't seen coconut palms--a signature tree--stripped bare, unlike in the other storms that I've listed, even though, over the long run, more Category 4/5 cyclones have likely impacted Grand Cayman, given its location, than those that hit the U.S. I've seen images showing numerous coconut palms stripped in Cabo San Lucas after Odile (2014), a storm that officially is 110 kt--high-end Category 3--at landfall in Mexico, though I believe that it should be 115 kt (low-end Category 4) instead.


  17. Honestly, that looks like a poorly-constructed wooden shack without proper trussing and anchoring. The tree damage in the background is quite comparable to what I witnessed in Southeast Florida (Boca Raton) following low-end Category 1 conditions in Wilma (2005). In that storm, most palms retained their foliage, and many mature, deciduous trees were only partly defoliated at best. That is what you see in the background. My visual estimates of low-end Category 1 winds in that storm are consonant with official observations, radar estimates, and judgments by the NHC (see Wilma's post-seasonal report).

     

    By contrast, I have seen numerous images and descriptions of true Category 4/5 impacts from the inner cores of Andrew, Charley, STY Haiyan, Hugo, 1926 Miami, 1928 San Felipe II/Okeechobee (in Guadeloupe, Puerto Rico, and South FL), 1935 Labor Day, Janet, Gilbert, David, Iniki, and Dean. (I could argue for 1945 Homestead, but I haven't seen enough evidence to judge. For other Category 4/5 hits, inside or outside the U.S., I haven't seen enough data either.) The visual evidence for true Category 4/5 damage was very strong, compared to that in other storms.

    The tree damage was immensely more severe in those cases, with shredding/snapping of mature, hard pines and coconut palms, among other species. Species that defoliate easily, especially in the seasonally dry (sub-)tropical forests of Mexico, the Caribbean, and South Florida, were completely stripped of leaves in several of the cases that I noted. (For good U.S. examples, see North Captiva Island and the Deering Estate after Charley and Andrew, respectively; Google or read up on the "Seaward Explorer" for the latter.) In the '35 hurricane, I've even seen photos in publications showing debarking of entire mangrove forests at Cape Sable and within the inner core on the Keys--something that I've yet to see in any other tropical cyclone.

     

    To be honest, the Category 4/5 storms that I've mentioned are among a relative handful for which I've seen conclusive visual evidence to support the official NHC designations at landfall. For many "official" Category 4/5 landfalls like Carla, Camille, Audrey (which will almost certainly be downgraded), Hazel, 1900/1915 Galveston, 1916 Texas, and others, I have yet to see convincing structural or vegetative, wind-caused damage to substantiate their official wind speeds. This is especially true for storms that made landfall north of the latitude of southern Florida, with the notable exception of Hugo in South Carolina.

    For instance, images from Pass Christian, Mississippi, which experienced the peak winds of Camille, show only modest tree damage a few blocks inland, outside the surge zone, with only some mature trees closest to the water exhibiting classic denuding/removal of large limbs. Images of Pass Christian after Katrina, a much weaker storm, showed the same phenomenon. Official reports on Camille showed that most mature pines inland were uprooted rather than snapped, despite Camille's rather quick forward speed. In short, there is little, if any, visual evidence to support anything close to the official 150-kt landfall winds for Camille, despite its impressive radar presentation at the time.

    Hazel is another egregious case that may hold some relevance for Patricia's. Hazel was an accelerating tropical cyclone ahead of a mid-latitude system that encountered increasing shear as it neared the North Carolina/SC border, albeit from baroclinic forcing. Like Sandy and the 1938 hurricane, Hazel was broadening and undergoing extratropical transition/deepening as it neared the coast; the winds in the former two weakened as they did so. I have seen many images from the NC coast after Hazel, and not a single image that I can recall shows significant tree/structural damage away from the immediate beachfront. As in Camille/Katrina, most damage was from coastal erosion, waves, and surge.

    My hunch is that Hazel may have been substantially weaker than its official 115-kt landfall winds indicate, a contention bolstered by recent cases like Sandy. I also feel that Hazel's leaving the Gulf Stream brought it over the cooler shelf waters closer to the NC/SC coast, just as Camille would have begun encountering lower oceanic heat content after bypassing the Mississippi Delta. Storms like Camille, which had undergone an eyewall replacement several hours before landfall, and Hazel, both of which were expanding in size, may have had more trouble translating their winds to the surface, given a weaker gradient, lower OHC, and/or (as in Hazel's case) increasing vertical shear. Carla and Audrey likely faced similar conditions.

     

    The point is that even lower OHC can potentially affect how well a storm's peak winds translate to the surface, even when other conditions are seemingly conducive for an intense hurricane. It's possible that Camille's winds may have not strengthened from 135 to 150 kt as it neared MS in its final hours, even though its central pressure dropped from 919 to 900 mb. Similarly, Carla could have deepened to 931 mb, and Hazel to 938 mb, at landfall, yet without a corresponding increase in winds. (Sandy deepened to 940 mb even as its winds decreased a bit from 85 to 80 kt. As for Audrey, I have serious doubts that it was still deepening as it hit, given its evident structural deterioration on radar.)

    Hazel and Camille both had near-average or smaller-than-average radii of maximum winds as they made U.S. landfalls. If my hypothesis is correct, even though those storms deepened before landfall, their winds may have stayed the same or even decreased. Similarly, even as Patricia maintained a small inner core as it made landfall, the effects of increasing shear and downsloping off the mountainous terrain likely reduced the ratio between flight-level and surface wind speeds, resulting in a lower conversion to standard 10-m elevation. In that case, its winds could have easily decreased to 125-135 kt (or perhaps even a bit lower) before landfall.

    While a small but sheared storm may be able to retain a high conversion for some hours, the combination of shear and dry air/downsloping has been shown to rapidly affect even well-developed, compact hurricanes. Plus, forecasting experience has shown that small, extremely intense hurricanes are more vulnerable to sudden changes in environmental parameters than are large storms. Dry air intrusion and increasing shear would have induced rapid weakening a cyclone like Patricia, which is what we indeed observed. That could explain the steady warming of the CDO before landfall, coincident with the shifting of the strongest convection to the western quadrant.

     

    If my hypothesis is correct, and we are justified in assuming that many (if not most) of our estimated intensities for intense tropical cyclones over land are incorrect, then it amply illustrates the weakness of our historical records and how much we still need to know about complex structural dynamics and interactions between the atmosphere and ocean surface(s) in tropical cyclones undergoing changing environmental parameters at different latitudes/longitudes. Unfortunately, without more recon and other remote sampling of intense cyclones, we won't be able to develop supercomputers able to resolve these issues, much less improve our reanalysis efforts.

     

    In short, even taking into account recon and satellite estimates, along with land observations, does not necessarily tell the whole story about maximum sustained winds at 10 m in a tropical cyclone. My preliminary analysis indicates that we may be only reasonably certain about the winds at landfall in a handful (13 or so) of the many "official" Category 4/5 tropical cyclones on record, at least in the Atlantic and North Pacific basins. These cases had support from visual images and/or descriptions of wind-caused damage as well as scientific observations (recon, satellite, surface/ships, etc.). These storms, since 1900, are as follows, with my unofficial estimates of sustained winds included:

    • 1926 Miami hurricane: 120–130 kt (South FL)
    • 1928 Okeechobee: 120–130 kt (Guadeloupe), 130–140 kt (Puerto Rico), 120–130 kt (South FL)
    • 1935 Labor Day: 170–185 kt (South FL [Keys])
    • Janet 1955: 140–150 kt (Islas del Cisne/Swan Is., Honduras), 150–165 kt (Quintana Roo, Yucatán)
    • David 1979: 130–140 kt (Dominica), 145–155 kt (Dominican Republic)
    • Gilbert 1988: 115–125 kt (Jamaica), 140–150 kt (Quintana Roo, Yucatán)
    • Hugo 1989: 120–130 kt (Guadeloupe), 110–120 kt (Puerto Rico), 125–135 kt (SC)
    • Andrew 1992: 145–155 kt (South FL)
    • Iniki 1992: 120–130 kt (Kauai, Hawaii)
    • Charley 2004: 125–135 kt (southern FL)
    • STY Haiyan 2013: 165–175 kt (strongest near Guiuan, Eastern Samar, Philippines)
    • Dean 2007: 145–155 kt (Quintana Roo, Yucatán)

    Note that my strict standards leave off a number of "official" or probable cases, such as Felix 2007 (due to lack of documentary evidence for Category 4/5 wind damage) and the 1959 Mexican hurricane.

    Is anyone willing to comment on this? I'd be interested in hearing other views. :)


  18. That said, please allow me to clarify some apparent misinterpretations of my previous posts.  First, I did say that the difference between Patricia having come ashore at peak intensity (175-180 kt.) and at high-end category-four strength may very well have been the difference between life and death for Josh and residents in that area.  There is no discrepancy when I state the same possibility may have been the case if Patricia had made landfall at the current operational 145 kt. intensity. Interpreting all of the available data to suggest a 125-130 kt. landfall intensity is the 10-15 kt. differential I referred to in the post you quoted...that again, may very well have been the difference between life and death for the aforementioned.  It's most important to note that in each case, I specifically said it in the context of "could" ("may very well have been"), which isn't an inaccurate remark or one that is contradictory to anything else I stated in that regard.

     

    Secondly, I did express that it would be difficult for one to discern the difference in damage between a 130 kt. category-four and a 140 kt. category-five, and I still believe that to be the case.  The reasoning being that most structures aren't built to withstand winds of such severe intensity.  Furthermore, these type of wind speeds are so rare (and extreme) that it would be very difficult, if not virtually impossible, for anyone to tell the difference in those respective wind speeds without an anemometer (i.e. based solely on a visual estimation).

     

    All that being said, I didn't specifically say, or meant to insinuate, that there isn't an increased danger to both life and property by a 10-15 kt. increase in the MSW...for there definitely is...as I alluded to in my preceding post.

     

    Gotta go crash.  Good night!

    Maybe this is a separate argument, but I can't think of a single tropical cyclone, globally, that killed more than 50-100 people from wind alone. I have read many sources on the history of tropical cyclones worldwide, and I've yet to find a reliable source indicating such a high death toll solely attributable to intense winds. This is true even for the strongest landfalls such as the 1935 hurricane, Andrew, Charley, Hugo, Janet, Haiyan, Camille, etc. If we were to estimate death tolls by the strength of a storm, then Andrew, based on its damage, should have caused hundreds of deaths. The actual toll in the storm, based on direct deaths, was 15 in the worst-hit areas of South Florida.

     

    All evidence that I've seen, including the judgment of former meteorologists, is that the vast majority (likely ≥ 75-80%) of deaths in tropical cyclones have been related to inland flooding or storm surge. All the Category 4/5 landfalls that caused 100+ deaths seem to have done so via storm surge or flooding/mudslides. In Camille, for instance, I don't think that there was a single death attributable to major hurricane winds at any particular location. All the deaths in the U.S. were from storm surge and inland flooding, with a relative handful from falling/uprooted trees (indicative of tropical storm-force or Category 1 winds).

     

    As you've said, a collapsed structure is a collapsed structure, and most inhabited areas don't experience the strongest winds in a Category 4/5 cyclone, even one that is rapidly deepening, especially if the system is compact. Given that lightweight or poorly anchored structures disintegrate in even minimal hurricane winds, the practical, wind-based impact from a Category 1/2 would be the same as that of a Category 4/5...at least on frail structures, such as those in the rural fishing villages that Patricia impacted. Yet so far, we have heard of very few direct deaths from Patricia, almost none of them wind-related.

    My point is that, based on historical experience, my own judgment is that, for certain types of (weak) structures, there is little difference between the impact of a weak storm and a major hurricane...much less between a 130-kt hit and a 145-kt hit. Given that we haven't directly sampled the strongest winds on land in a 130- or 145-kt landfall, we don't have much empirical data with which to compare the wind-based damages at the site of strongest winds in each case. We only have subjective, visual estimates.

     

    Based on these data, I don't think that we can suggest that a 130-kt landfall would save more lives than a 145-kt landfall, given the relatively low number of wind-caused deaths in intense tropical cyclones and the varying impacts such winds have on structures, depending on construction standards, the duration of the strongest winds, etc. Well-built, poured-concrete structures can survive winds into Category 5 status, so, for those buildings, there would seem to be little difference between 130- and 145-kt winds.

     

    (Case in point: Andrew and Charley made their U.S. landfalls at 145 and 130 kt, respectively, but even in the core, I don't think that any structures experienced the maximum winds. Charley's peak winds passed close to North Captiva Island, but we don't have empirical evidence that homes there encountered 130-kt winds. Andrew's peak, 145-kt winds apparently affected the thinly populated mangroves on the immediate shoreline of Biscayne Bay.)

    Again, this is just my opinion, and you're welcome to disagree.

     

    (I do find it interesting that, given your Southern emphasis on courtesy and due respect, you sometimes come off, at least in my view, as being rather defensive and discourteous in your posts. Maybe honor is a non-negotiable for you, and you may have a trigger finger, but I would appreciate a bit more restraint in your tone, no matter how often others may misconstrue your posts. If you don't like other people's insinuations, then don't descend to their level, please. Just ignore them. That's my friendly advice. :) )


  19. There are a lot of models showing something along these lines. Most strong Ninos have been followed by a Nina the winter afterwards of varying strengths.

    With changes in the global circulation this winter and early next spring, the 2016 Atlantic hurricane season could the most interesting since 2010. An emerging -PDO and a late-winter/early-spring -NAO would potentially aid in a more moist basin and a resurgent +AMO. Add an emergent La Niña reducing global AAM and you have the potential for lower shear in the Caribbean thanks to reduced forcing in the Pacific. Almost all of the most active Atlantic seasons, ACE-wise, occurred within two years of El Niño episodes. In five of the eight seasons following strong Niños (since 1950), there was an ACE increase of ≥ 33%.


  20. As I've mentioned a couple times already, that 10-15 kt. difference in the MSW may very well have been the difference between life and death for some. So, the reanslysis of Patricia's landfalling intensity is far more consequential than the sarcastic example you listed above.

    P.s. I'm going to stop here for I've had an incredibly long day, and have now been awake for more than 39 hours straight. In truth, it's all I can do to just put two sentences together. That said, I hope each one of you have a great rest of the night and a good day, tomorrow!

    I think that you're contradicting yourself. You previously said that the difference between its hitting at peak strength (175-185 kt) and striking at 130-145 kt could have saved the lives of the iCyclone crew and local residents. You explicitly said, when asked, that the difference between a strong Category 4 and a low-end Category 5 is marginal at best, and in either case, even people in the core, a few blocks inland, would have likely missed the strongest winds. Damage, as you've admitted, would be similar, whether the storm hit at 130 or 145 kt.

     

    (If your lack of sleep is affecting the tone of your responses and your perception of reality, please get some sleep. Even an interesting storm isn't worth it. Take my kind advice seriously. :) )