Guest guest Posted August 12, 2004 Report Share Posted August 12, 2004 Re Hurricane Watch now on in Florida. The following is most likely toooo much information, but it’s nice to have all the data when you need it. Furthermore, there is a great piece of Hurricane Tracking Software called “Tracking the Eye” which has up to the minute data on current storms which I’ve used as an educational tool with many kids. It’s a great program that also teaches about Latitude and Longitude (charting). You can download a free version from: http://www.hurricanesoftware.com/ FAQ by Dr. Landsea FAQ: HURRICANES, TYPHOONS, AND TROPICAL CYCLONES --- PART I: DEFINITIONS, BASIC QUESTIONS, AND BASIN INFORMATION By Dr. Christopher W. Landsea Department of Atmospheric Science Colorado State University Fort Collins, CO 80523 landsea 1 June, 1995 This is currently a two-part FAQ (Frequently Asked Questions report) that is in its first incarnation (version 1.0). Thus, there may be some errors or discrepancies that have not yet been found. If you do see an item that needs correction, please contact me directly. This file (Part I) contains various definitions, answers for some specific questions, and information about the various tropical cyclone basins. Part II provides sites that you can access both real-time information about tropical cyclones, what is available on-line for historical storms, as well as good books to read and various references for tropical cyclones. Keep in mind that this FAQ is not considered a reviewed paper to reference. Its main purpose is to provide quick answers for (naturally) frequently asked questions as well as to be a pointer to various sources of information. I'd like to thank various people for helping to put together this FAQ: Sim Aberson, Jack Beven, and Gary Padgett all provided substantial bits to this FAQ. Also thanks to the many people who provided additional questions for me to answer: Ilana Stern, Dave Blanchard, Ken Fung, James (I R A Aggie) Stricherz, Neal Dorst, Mike Dettinger, Jan Schloerer, and Tom Berg. If I didn't get to all the suggested FAQs, I'll try to include them in future versions. Where can I get the latest version of this document????? ----------------------- The two portions for this FAQ are posted monthly on sci.geo.meteorology and on bit.listserv.wx-talk usually early in each month. One can also ftp to retrieve the latest files at: downdry.atmos.colostate.edu. Login as 'anonymous' and password as your email address. The files are in the pub directory. If you do not have ftp access, you can request copies from me directly via email. Plans are being made to have this available via a WWW site as well. ****************************************************** OUTLINE ------- DEFINITIONS, BASIC QUESTIONS, AND BASIN INFORMATION 1) What is a hurricane, typhoon, or tropical cyclone? 2) Why are tropical cyclones named? 3a) What are the names for 1995 (Northern Hemisphere)? 3b) What are the names for 1995-1996 (Southern Hemisphere)? 4) How are tropical cyclones different from mid-latitude storms? 5) How are tropical cyclones different from tornadoes? 6) Which is the most intense tropical cyclone on record? 7) Which tropical cyclone intensified the fastest? 8) Which tropical cyclone has produced the highest storm surge? 9) What are the largest rainfalls associated with tropical cyclones? 10) Which are the largest and smallest tropical cyclones on record? 11) Which tropical cyclone lasted the longest? 12) Which tropical cyclones have caused the most deaths and most damage? 13) Tropical cyclone myths: 13a) Doesn't the low pressure in the tropical cyclone center cause the storm surge? 13b) Doesn't the friction over land kill tropical cyclones? 13c) Aren't big tropical cyclones also intense tropical cyclones? 14) What regions around the globe have tropical cyclones and who is responsible for forecasting there? 15) What are the average, most, and least tropical cyclones occurring in each basin? 16) What is the annual cycle of occurrence seen in each basin? 17) How are Australian tropical cyclones ranked? 18) How does El Nino-Southern Oscillation affect tropical cyclone activity around the globe? 19) Are we getting stronger and more frequent hurricanes, typhoons, and tropical cyclones in the last few years? 20) Why don't we try to destroy tropical cyclones by: pick one or more - a) seeding them with silver iodide, b) nuking them, c) placing a substance on the ocean surface, d) etc. ? ATLANTIC BASIN-SPECIFIC QUESTIONS 21) How are Atlantic hurricanes ranked? 22) For the U.S., what are the 10 most intense, 10 costliest, and 10 highest death toll hurricanes on record? 23) What is Prof. Gray's seasonal hurricane forecast for this year and what are the predictive factors? 24) What are those models that the Atlantic forecasters are talking about in the Inter-Governmental messages? ********************************************* 1) What is a hurricane, typhoon, or tropical cyclone? The terms " hurricane " and " typhoon " are regionally specific names for a strong " tropical cyclone " . A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation (Holland 1993). Tropical cyclones with maximum sustained surface winds (see note below) of less than 17 m/s (34 kt) are called " tropical depressions " . (This is not to be confused with the condition mid-latitude people get during a long, cold and grey winter wishing they could be closer to the equator ;-) Once the tropical cyclone reaches winds of at least 17 m/s they are typically called a " tropical storm " and assigned a name. If winds reach 33 m/s (64 kt), then they are called: a " hurricane " (the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E); a " typhoon " (the Northwest Pacific Ocean west of the dateline); a " severe tropical cyclone " (the Southwest Pacific Ocean west of 160E or Southeast Indian Ocean east of 90E); a " severe cyclonic storm " (the North Indian Ocean); and a " tropical cyclone " (the Southwest Indian Ocean) (Neumann 1993). Note that just the definition of " maximum sustained surface winds " depends upon who is taking the measurements. The World Meteorology Organization guidelines suggest utilizing a 10 min average to get a sustained measurement. Most countries utilize this as the standard. However the National Hurricane Center (NHC) and the Joint Typhoon Warning Center (JTWC) of the USA use a 1 min averaging period to get sustained winds. This difference may provide complications in comparing the statistics from one basin to another as using a smaller averaging period may slightly raise the number of occurrences (Neumann 1993). ********************************************** 2) Why are tropical cyclones named? Tropical cyclones are named to provide ease of communication between forecasters and the general public regarding forecasts, watches, and warnings. Since the storms can often last a week or longer and that more than one can be occurring in the same basin at the same time, names can reduce the confusion about what storm is being described. According to Dunn and Miller (1960), the first use of a proper name for a tropical cyclone was by an Australian forecaster early in this century. He gave tropical cyclone names " after political figures whom he disliked. By properly naming a hurricane, the weatherman could publicly describe a politician (who perhaps was not too generous with weather-bureau appropriations) as 'causing great distress' or 'wandering aimlessly about the Pacific.' " (Perhaps this should be brought back into use ;-) During World War II, tropical cyclones were informally given women's names by USA Air Force and Navy meteorologists (after their girlfriends or wives) who were monitoring and forecasting tropical cyclones over the Pacific. From 1950 to 1952, tropical cyclones of the North Atlantic Ocean were identified by the phonetic alphabet (Able-Baker-Charlie-etc.), but in 1953 the USA Weather Bureau switched to women's names. In 1979, the WMO and the USA National Weather Service (NWS) switched to a list of names that also included men's names. The Northeast Pacific basin tropical cyclones were named using women's names starting in 1959. In 1978, both men's and women's names were utilized. The Northwest Pacific basin tropical cyclones were given women's names officially starting in 1945 and men's names were also included beginning in 1979. The North Indian Ocean region tropical cyclones are not named. I could not find information as to when the Southwest India Ocean tropical cyclones were started to be named. (Anyone??) The Australian and South Pacific region (east of 90E, south of the equator) started giving women's names to the storms in 1964 and both men's and women's names in 1973. ********************************************** 3) What are the tropical cyclone names for 1995 and 1995-1996? NORTHERN HEMISPHERE TROPICAL CYCLONE NAMES FOR 1995 (Courtesy of Gary Padgett and Jack Beven) Atlantic, Gulf of Mexico, Caribbean Sea ------ Allison, Barry, Chantal, Dean, Erin, Felix, Gabrielle, Humberto, Iris, Jerry, Karen, Luis, Marilyn, Noel, Opal, Pablo, Roxanne, Sebastien, Tanya, Van, Wendy (Set was last used in 1989, when names were assigned down through Karen. Humberto replaces Hugo which was retired after its devastating visit to the Caribbean islands and South Carolina.) Eastern North Pacific (east of 140W) --------------------- Adolph, Barbara, Cosme, Dalilia, Erick, Flossie, Gil, Henriette, Ismael, Juliette, Kiko, Lorena, Manuel, Narda, Octave, Priscilla, Raymond, Sonia, Tico, Velma, Wallis, Xina, York, Zelda (Set was last used in 1989, when names were assigned down through Raymond, and in 1983, the entire set was used except for Xina, York, and Zelda.) Central North Pacific (from the dateline to 140W) --------------------- Oliwa, Paka, Upana, Wene, Alika, Ele, Huko, Ioke, Kika, Lana Western North Pacific (west of the dateline) --------------------- Chuck, Deanna, Eli, Faye, Gary, Helen, Irving, Janis, Kent, Lois, Mark, Nina, Oscar, Polly, Ryan, Sibyl, Ted, Val, Ward, Yvette, Zack, Angela, Brian, Colleen, Dan, Elsie, Forrest, Gay, Hunt, Irma, Jack, Koryn, Lewis, Marian, Nathan, Ofelia, Percy, Robyn, Steve, Tasha (This particular range of names from the circular list of 92 names was last used from early 1992 through mid-1993. Oscar replaces Omar, which was retired after its devastating strike on Guam in 1992.) North Indian Ocean ------------------ Tropical cyclones in this region are not named. SOUTHERN HEMISPHERE TROPICAL CYCLONE NAMES FOR 1995-1996 (Does anyone have this info??????) *************************** 4) How are tropical cyclones different from mid-latitude storms? The tropical cyclone is a low-pressure system which derives its energy primarily from evaporation from the sea in the presence of high winds and lowered surface pressure and the associated condensation in convective clouds concentrated near its center (Holland 1993). Mid-latitude storms (low pressure systems with associated cold fronts, warm fronts, and occluded fronts) primarily get their energy from the horizontal temperature gradients that exist in the atmosphere. Structurally, tropical cyclones have their strongest winds near the earth's surface (a consequence of being " warm-core " in the troposphere), while mid-latitude storms have their strongest winds near the tropopause (a consequence of being " warm-core " in the stratosphere and " cold-core " in the troposphere). ( " Warm-core " refers to being relatively warmer than the environment at the same pressure surface.) ****************************************** 5) How are tropical cyclones different from tornadoes? While both tropical cyclones and tornadoes are atmospheric vortices, they have little in common. Tornadoes have diameters on the scale of 100s of meters and are produced from a single convective storm. A tropical cyclone, however, has a diameter on the scale of 100s of *kilometers* and is comprised of several to dozens of convective storms. Additionally, while tornadoes require substantial vertical shear of the horizontal winds to provide ideal conditions for tornado genesis, tropical cyclones require very low values (less than 10 m/s) of tropospheric vertical shear in order to form and grow. These vertical shear values are indicative of the horizontal temperature fields for each phenomena: tornadoes are produced in regions of large temperature gradient, while tropical cyclones are generated in regions of near zero horizontal temperature gradient. Tornadoes are primarily an over-land phenomena as solar heating of the land surface usually contributes toward the development of the thunderstorm that spawns the vortex (though over-water tornadoes have occurred). In contrast, tropical cyclones are purely an oceanic phenomena - they die out over-land due to a loss of a moisture source. Lastly, tropical cyclones have a lifetime that is measured in days, while tornadoes typically last on the scale of minutes. An interesting side note is that tropical cyclones at landfall often provide the conditions necessary for tornado formation. As the tropical cyclone makes landfall and begins decaying, the winds at the surface die off quicker than the winds at, say, 850 mb. This sets up a fairly strong vertical wind shear that allows for the development of tornadoes, especially on the tropical cyclone's right side (with respect to the forward motion of the tropical cyclone). (Novlan and Gray 1974) ***************************** 6) Which is the most intense tropical cyclone on record? Typhoon Tip in the Northwest Pacific Ocean on 12 October 1979 was measured to have a central pressure of 870 mb and estimated surface sustained winds of 85 m/s (165 kt) (Dunnavan and Diercks 1980). Typhoon Nancy on 12 September, 1961 is listed in the best track data for the Northwest Pacific region as having an estimated maximum sustained winds of 185 kt with a central pressure of 888 mb. However, it is now recognized (Black 1992) that the maximum sustained winds estimated for typhoons during the 1940s to 1960s were too strong and that the 185 kt (and numerous 160 kt to 180 kt reports) is somewhat too high. While the central pressures for the Northwest Pacific typhoons are the lowest globally, the North Atlantic hurricanes have provided sustained wind speeds possibly comparable to the Northwest Pacific. From the best track database, both Hurricane Camille (1969) and Hurricane Allen (1980) have winds that are estimated to be 165 kt. Measurements of such winds are inherently going to be suspect as instruments often are completely destroyed or damaged at these speeds. *********************************** 7) Which tropical cyclone intensified the fastest? Typhoon Irma on 11-12 November, 1971 in the Northwest Pacific Ocean deepened by 51 mb in 8 hr and 97 mb in 24 hr (Holliday 1973). Estimated surface sustained winds increase a maximum of 35 kt in 6 hr and 85 kt in one day (from 70 to 155 kt). ******************************** 8) Which tropical cyclone has produced the highest storm surge? The Bathurst Bay Hurricane produced a 13 m (about 42 ft) surge in Bathurst Bay, Australia in 1899 (Whittingham 1958). ********************************** 9) What are the largest rainfalls associated with tropical cyclones? 12 hr: 1144 mm (45.0 " ) at Foc-Foc, La Reunion Island in Tropical Cyclone Denise, 7-8 January, 1966. 24 hr: 1825 mm (71.8 " ) at Foc-Foc, La Reunion Island in Tropical Cyclone Denise, 7-8 January, 1966. 48 hr: 2467 mm (97.1 " ) at Aurere, La Reunion Island 8-10 April, 1958. 72 hr: 3240 mm (127.6 " ) at Grand-Ilet, La Reunion Island in Tropical Cyclone Hyacinthe, 24-27 January, 1980. 10 d: 5678 mm (223.5 " ) at Commerson, La Reunion Island in Tropical Cyclone Hyacinthe, 18-27 January, 1980. (Holland 1993) ************************************* 10) Which are the largest and smallest tropical cyclones on record? Typhoon Tip had gale force winds (15 m/s) which extended out for 1100 km in radius in the Northwest Pacific on 12 October, 1979 (Dunnavan and Diercks 1980). Tropical Cyclone Tracy had gale force winds that only extended 50 km radius when it struck Darwin, Australia, on 24 December, 1974 (Bureau of Meteorology 1977). ********************************** 11) Which tropical cyclone lasted the longest? Hurricane/Typhoon John lasted 31 days as it traveled both the Northeast and Northwest Pacific basins during August and September 1994. (It formed in the Northeast Pacific, reached hurricane force there, moved across the dateline and was renamed Typhoon John, and then finally recurved back across the dateline and renamed Hurricane John again.) Hurricane Ginger was a tropical cyclone for 28 days in the North Atlantic Ocean back in 1971. ********************************* 12) Which tropical cyclones have caused the most deaths and most damage? " The death toll in the infamous Bangladesh Cyclone of 1970 has had several estimates, some wildly speculative, but it seems certain that at least 300,000 people died from the associated storm tide [surge] in the low-lying deltas. " (Holland 1993) The largest damage caused by a tropical cyclone as estimated by monetary amounts has been Hurricane Andrew (1992) as it struck the Bahamas, Florida and Louisiana, USA: US $20 to 25 *Billion*. Almost all of this figure was due to destruction in southeast Florida. *********************************************************** 13) Tropical cyclone myths: 13a) Doesn't the low pressure in the tropical cyclone center cause the storm surge? No. Many people assume that the partial vacuum at the center of a tropical cyclone allows the ocean so rise up in response, thus causing the destructive storm surges as the cyclone makes landfall. However, this effect would be, for example, with a 900 mb central pressure tropical cyclone, only 1.0 m (3 ft). The total storm surge for a tropical cyclone of this intensity can be from 6 to 10 m (19 to 33 ft), or more. Most (>85%) of the storm surge is caused by winds pushing the ocean surface ahead of the storm on the right side of the track (left side of the track in the Southern Hemisphere). Since the surface pressure gradient (from the tropical cyclone center to the environmental conditions) determines the wind strength, the central pressure indirectly does indicate the height of the storm surge, but not directly. Note also that individual storm surges are dependent upon the coastal topography, angle of incidence of landfall, speed of tropical cyclone motion as well as the wind strength. ********************************* 13) Tropical cyclone myths: 13b) Doesn't the friction over land kill tropical cyclones? No. Friction acts to accelerate the low-level inflow, which by itself is not harmful to the tropical cyclone. But over land the tropical cyclone lacks the moisture flux from the surface that fuels the convection. Without the deep convection near the storm center, the cyclone rapidly fills. Numerical simulations have actually shown that if a tropical cyclone makes landfall over land that is very moist (a swampy region for example), that the tropical cyclone *intensifies* (Tuleya and Kurihara 1978). Wakimoto and Black (1993) suggest that this might have occurred in the case of Hurricane Andrew striking Florida. **************************** 13) Tropical cyclone myths: 13c) Aren't big tropical cyclones also intense tropical cyclones? No. There is very little association between intensity (either measured by maximum sustained winds or by central pressure) and size (either measured by radius of 15 m/s (gale force) winds or the radius of the outer closed isobar) (Weatherford and Gray (1988). Hurricane Andrew is a good example of a very intense tropical cyclone (922 mb central pressure and 64 m/s (125 kt) sustained winds at landfall in Florida) that was also relatively small (15 m/s winds extended out only about 150 km from the center). Weatherford and Gray (1988) also showed that changes of both intensity and size are essentially independent of one another. ************************************** 14) What regions around the globe have tropical cyclones and who is responsible for forecasting there? There are seven tropical cyclone " basins " where storms occur on a regular basis: --- Atlantic basin (including the North Atlantic Ocean, the Gulf of Mexico, and the Caribbean Sea) --- Northeast Pacific basin (from Mexico to about the dateline) --- Northwest Pacific basin (from the dateline to Asia including the South China Sea) --- North Indian basin (including the Bay of Bengal and the Arabian Sea) --- Southwest Indian basin (from Africa to about 100E) --- Southeast Indian/Australian basin (100E to 142E) --- Australian/Southwest Pacific basin (142E to about 120W) The National Hurricane Center in Miami, Florida, USA has responsibilities for monitoring and forecasting tropical cyclones in the Atlantic and Northeast Pacific basin east of 140W. The Central Pacific Hurricane Center has responsibilities for the remainder of the Northeast Pacific basin to the dateline. The Northwest Pacific basin is shared in forecasting duties by China, Thailand, Korea, Japan, the Philippines, and Hong Kong. The North Indian basin tropical cyclones are forecasted by India, Thailand, Pakistan, Bangladesh, Burma, and Sri Lanka. Reunion Island, Madagascar, Mozambique, and Kenya provide forecasts for the Southwest Indian basin. Australia and Indonesia forecast tropical cyclone activity in the Southeast Indian/Australian basin. Lastly, for the Australian/Southwest Pacific basin Australia, Papua New Guinea, Fiji, and New Zealand forecast tropical cyclones. Note also that the USA Joint Typhoon Warning Center (JTWC) issues warnings for tropical cyclones in the Northwest Pacific, the North Indian, the Southwest Indian, the Southeast Indian/Australian, and the Australian/Southwest Pacific basins, though they are not specifically tasked to do so by the WMO. (Neumann 1993) ************************************* 15) What are the average, most, and least tropical cyclones occurring in each basin? Based on data from 1968-1989 (1968/69 to 1989/90 for the Southern Hemisphere): Tropical Storm or stronger Hurricane/Typhoon/Severe Tropical Cyclone (>17 m/s sustained winds) (>33 m/s sustained winds) -------- Basin Most/Least Average Most/Least Average Atlantic 18/4 9.7 12/2 5.4 NE Pacific 23/8 16.5 14/4 8.9 NW Pacific 35/19 25.7 24/11 16.0 N Indian 10/1 5.4 6/0 2.5 SW Indian 15/6 10.4 10/0 4.4 SE Indian/Aus 11/1 6.9 7/0 3.4 Aus/SW Pacific 16/2 9.0 11/2 4.3 Globally 103/75 83.7 65/34 44.9 Note that the data includes subtropical storms in the Atlantic basin numbers. (Neumann 1993) ******************************** 16) What is the annual cycle of occurrence seen in each basin? While the Atlantic hurricane season is " officially " from 1 June to 30 November, the Atlantic basin shows a very peaked season with 78% of the tropical storm days, 87% of the minor (Saffir-Simpson Scale categories 1 and 2 - see subject 21) hurricane days, and 96% of the intense (Saffir-Simpson categories 3, 4 and 5) hurricane days occuring in August through October (Landsea 1993). Peak activity is in early to mid September. Once in a few years there may be a tropical cyclone occurring " out of season " - primarily in May or December. The Northeast Pacific basin has a broader peak with activity beginning in late May or early June and going until late October or early November with a peak in storminess in late August/early September. The Northwest Pacific basin has tropical cyclones occurring all year round regularly though there is a distinct minimum in February and the first half of March. The main season goes from July to November with a peak in late August/early September. The North Indian basin has a double peak of activity in May and November though tropical cyclones are seen from April to December. The severe cyclonic storms (>33 m/s winds) occur almost exclusively from April to June and late September to early December. The Southwest Indian and Australian/Southeast Indian basins have very similar annual cycles with tropical cyclones beginning in late October/early November, reaching a double peak in activity - one in mid-January and one in mid-February to early March, and then ending in May. The Australian/Southeast Indian basin February lull in activity is a bit more pronounced than the Southwest Indian basin's lull. The Australian/Southwest Pacific basin begin with tropical cyclone activity in late October/early November, reaches a single peak in late February/early March, and then fades out in early May. Globally, September is the most active month and May is the least active month. (Neumann 1993) *************************************** 17) How are Australian tropical cyclones ranked? The Australian forecasters have developed a scale for tropical cyclone intensity for storms in their area of responsibility - 90 to 160E (Holland 1993). Note that the sustained winds are based upon a 10 min averaging period instead of the USA 1 minute period. Australian Scale Sustained Winds (km/hr) 1 63-90 km/hr 2 91-125 3 126-165 4 166-225 5 > 225 There are further comments on this scale in subject 21). ***************************** 18) How does El Nino-Southern Oscillation affect tropical cyclone activity around the globe? The effect of El Nino-Southern Oscillation (ENSO) on Atlantic tropical cyclones is described in subject 23). The Australian/Southwest Pacific shows a pronounced shift back and forth of tropical cyclone activity with fewer tropical cyclones between 145 and 165E and more from 165E eastward across the South Pacific during El Nino (warm ENSO) events. There is also a smaller tendency to have the tropical cyclones originate a bit closer to the equator. The opposite would be true in La Nina (cold ENSO) events. See papers by Nicholls (1979), Revell and Goulter (1986), Dong (1988), and Nicholls (1992). The western portion of the Northeast Pacific basin (140W to the dateline) has been suggested to experience more tropical cyclone genesis during the El Nino year and more tropical cyclones tracking into the sub-region in the year following an El Nino (Schroeder and Yu 1995), but this has not been completely documented yet. The Northwest Pacific basin, similar to the Australian/Southwest Pacific basin, experiences a change in location of tropical cyclones without a total change in frequency. Pan (1981), Chan (1985), and Lander (1994) detailed that west of 160E there were reduced numbers of tropical cyclone genesis with increased formations from 160E to the dateline during El Nino events. The opposite occurred during La Nina events. Again there is also the tendency for the tropical cyclones to also form closer to the equator during El Nino events than average. The eastern portion of the Northeast Pacific, the Southwest Indian, the Southeast Indian/Australian, and the North Indian basins have either shown little or a conflicting ENSO relationship and/or have not been looked at yet in sufficient detail. ************************************ 19) Are we getting stronger and more frequent hurricanes, typhoons, and tropical cyclones in the last few years? Globally, probably not. For the Atlantic basin, definitely not. In fact, documented in Landsea (1993), it is shown that the intense hurricanes (Saffir-Simpson scale 3, 4, and 5 - defined in subject 21)) have actually gone *down* during the 1970s and the 1980s, both in all basin intense hurricanes as well as those making landfall along the U.S. coastline. " With Andrew in 1992, have things changed during the 1990s? " No. Even taking into account Andrew, the period 1991 to 1994 has been the *quietest* four years on record - using reliable data going back to 1944. Some more interesting tidbits about Atlantic tropical cyclones: * no change in total frequency of tropical storms and hurricanes over 50 years, * a strong *DECREASE* in numbers of intense hurricanes, * no change in the strongest hurricanes observed each year, * A moderate *DECREASE* in the max intensity reached by all storms over a season, * no hurricanes have been observed over the Caribbean Sea in the last 4 years - the longest period of lack of hurricanes in the area since 1899, * 1991-1994 is the quietest (in terms of frequency of total storms - 7.5 per year, hurricanes - 3.8, and intense hurricanes - 1.0) four year period on record, since 1944. (This is work in progress that is being submitted for publication.) As for the other basins, Black (1992) has identified a moderately severe bias in the Northwest Pacific reported maximum sustained winds during the 1940s to the 1960s that makes interpretation of trends difficult for that region. Nicholls (1992) has shown that the numbers of tropical cyclones around Australia (105-165E) has decreased rather dramatically since the mid-1980s. Some of this reduction is undoubtedly due to having more El Nino events since that time (i.e. 1986-87, 1991-2, 1993, 1994-95). However, even taking into account the El Nino effect, there is still a reduction that is unexplained and may be due to changes in tropical cyclone monitoring. The other basins have not been examined for trends, partly because the data will likely not be trustworthy before the advent of the geo-stationary satellites in the mid-1960s. IMHO, I would suspect though that the western portion of the Northeast Pacific, the eastern portion of the Northwest Pacific, and the South Pacific east of 165E would have a real upward trend of tropical cyclone occurrences because of the more frequent El Nino events in the last decade or so (see section 18 for more information on El Nino effects). ********************************** 20) Why don't we try to destroy tropical cyclones by: pick one or more - a) seeding them with silver iodide, b) nuking them, c) placing a substance on the ocean surface, d) etc. ? Actually for a couple decades NOAA and its predecessor tried to weaken hurricanes by dropping silver iodide (a substance that serves as a powerful ice nuclei) into the rainbands of the storms. The idea was that the silver iodide would enhance the thunderstorms of the rainband by causing the supercooled water to freeze, thus liberating the latent heat of fusion and helping the rainband to grow at the expense of the eyewall. With a weakened convergence to the eyewall, the strong inner core winds would also weaken quite a bit. Neat idea, but it, in the end, had a fatal flaw: there just isn't much supercooled water available in hurricane convection - the buoyancy is fairly small and the updrafts correspondingly small compared to the type one would observe in mid-latitude continental super or multicells. The few times that they did seed and saw a reduction in intensity was undoubtedly due to what is now called " concentric eyewall cycles " . Concentric eyewall cycles naturally occur in intense tropical cyclones (wind > 50 m/s or 100 kt). As tropical cyclones reach this threshold of intensity, they usually - but not always - have an eyewall and radius of maximum winds that contracts in fairly small, say 10 to 25 km. At this point, some of the outer rainbands may organize into an outer ring of thunderstorms that slowly moves inward and robs the inner eyewall of its needed moisture and momentum. During this phase, the tropical cyclone is weakening (i.e. the maximum winds die off a bit and the central pressure goes up). Eventually the outer eyewall replaces the inner one completely and the storm can be the same intensity as it was previously or, in some cases, even stronger. This concentric eyewall cycle occurred in Hurricane Andrew (1992) right before it hit Miami. Thus nature accomplishes what NOAA had hoped to do artificially. No wonder that the first few experiments were thought to be successes. To learn about the STORMFURY project as it was called, read Willoughby et al. (1985). To learn more about concentric eyewall cycles, read Willoughby et al. (1982) and Willoughby (1990). As for the other ideas, there has been some experimental work in trying to develop a liquid that when placed over the ocean surface would prevent evaporation from occurring. If this worked in the tropical cyclone environment, it would probably have a detrimental effect on the intensity of the storm as it needs huge amounts of oceanic evaporation to continue to maintain its intensity. However, finding a substance that would be able to stay together in the rough seas of a tropical cyclone proved to be the downfall of this idea. (Does anyone have a good reference for this?) There was also suggested about 20 years ago (Gray et al. 1976) that the use of carbon black (or soot) might be a good way to modify tropical cyclones. The idea was that one could burn a large quantity of a heavy petroleum to produce vast numbers of carbon black particles that would be released on the edges of the tropical cyclone in the boundary layer. These carbon black aerosols would produce a tremendous heat source simply by absorbing the solar radiation and transferring the heat directly to the atmosphere. This would provide for the initiation of hunderstorm activity outside of the tropical cyclone core and, similarly to STORMFURY, weaken the eyewall convection. This suggestion has never been carried out in real-life. Lastly, there always appears ideas during the hurricane season that one should simply use nuclear weapons to try and destroy the storms. Apart from the concern that this might not even alter the storm, this approach neglects the problem that the released radiation would fairly quickly move with the tradewinds to over land. Needless to say, this is not a good idea. < Start Soap Box > Perhaps the best solution is not to try to alter or destroy the tropical cyclones, but just learn to co-exist better with them. Since we know that coastal regions are vulnerable to the storms, enforce building codes that can have houses stand up to the force of the tropical cyclones. Also the people that choose to live in these locations should willing to shoulder a fair portion of the costs in terms of property insurance - not exorbanent rates, but ones which truly reflect the risk of living in a vulnerable region. < End Soap Box > ********************************* 21) How are Atlantic hurricanes ranked? The USA utilizes the Saffir-Simpson hurricane intensity scale (Simpson and Riehl 1981) for the Atlantic and Northeast Pacific basins to give an estimate of the potential flooding and damage to property given a hurricane's estimated intensity: Saffir-Simpson Maximum sustained Minimum surface Storm surge Category wind speed (m/s,kt) pressure (mb) (m,ft) - 1 33-42 m/s [64-83 kt] >= 980mb 1.0-1.7 m [3-5 ft] 2 43-49 [84-96] 979-965 1.8-2.6 [6-8] 3 50-58 [97-113] 964-945 2.7-3.8 [9-12] 4 59-69 [114-135] 944-920 3.9-5.6 [13-18] 5 > 69 [> 135] < 920 > 5.6 [> 18] 1: MINIMAL: Damage primarily to shrubbery, trees, foilage, and unanchored homes. No real damage to other structures. Some damage to poorly contructed signs. Low-lying coastal roads inundated, minor pier damage, some small craft in exposed anchorage torn from moorings. Example: Hurricane Jerry (1989) 2: MODERATE: Considerable damage to shrubbery and tree foilage; some trees blown down. Major damage to exposed mobile homes. Extensive damage to poorly constructed signs. Some damage to roofing materials of buildings; some window and door damage. No major damage to buildings. Coast roads and low-lying escape routes inland cut by rising water 2 to 4 hours before arrival of hurricane center. Considerable damage to piers. Marinas flooded. Small craft in unprotected anchorages torn from moorings. Evacuation of some shoreline residences and low-lying areas required. Example: Hurricane Bob (1991) 3: EXTENSIVE: Foilage torn from trees; large trees blown down. Practically all poorly constructed signs blown down. Some damage to roofing materials of buildings; some wind and door damage. Some structural damage to small buildings. Mobile homes destroyed. Serious flooding at coast and many smaller structures near coast destroyed; larger structures near coast damaged by battering waves and floating debris. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane center arrives. Flat terrain 5 feet of less above sea level flooded inland 8 miles or more. Evacuation of low-lying residences withing several blocks of shoreline possibly required. Example: Hurricane Gloria (1985) 4: EXTREME: Shrubs and trees blown down; all signs down. Extensive damage to roofing materials, windows and doors. Complete failures of roofs on many small residences. Complete destruction of mobile homes. Flat terrain 10 feet of less above sea level flooded inland as far as 6 miles. Major damage to lower floors of structures near shore due to flooding and battering by waves and floating debris. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane center arrives. Major erosion of beaches. Massive evacuation of all residences within 500 yards of shore possibly required, and of single-story residences within 2 miles of shore. Example: Hurricane Andrew (1992) 5: CATASTROPHIC: Shrubs and trees blown down; considerable damage to roofs of buildings; all signs down. Very severe and extensive damage to windows and doors. Complete failure of roofs on many residences and industrial buildings. Extensive shattering of glass in windows and doors. Some complete building failures. Small buildings overturned or blown away. Complete destruction of mobile homes. Major damage to lower floors of all structures less than 15 feet above sea level within 500 yards of shore. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane center arrives. Massive evacuation of residential areas on low ground within 5 to 10 miles of shore possibly required. Example: Hurricane Camille (1969) Note that tropical storms are not on this scale, but can produce extensive damage with rainfall-produced flooding. Note also that category 3, 4, and 5 hurricanes are collectively referred to as intense (or major) hurricanes. These intense hurricanes cause over 70% of the damage in the USA even though they account for only 20% of tropical cyclone landfalls (Landsea 1993). Note that in comparison with the Australian scale (subject 17), Australian 1 and and most of Australian 2 are within the tropical storm categorization (i.e. would not be on the Saffir-Simpson scale). An Australian 3 would be approximately equal to either a Saffir-Simpson category 1 or 2 hurricane. An Australian 4 would be about the same as a Saffir-Simpson category 3 or 4 hurricane. An Australian 5 would be about the same as a Saffir-Simpson category 5 hurricane. ********************************* 22) For the U.S., what are the 10 most intense, 10 costliest, and 10 highest death toll hurricanes on record? Updated from Hebert et al. (1992): 10 Most Intense USA (continental) hurricanes from 1900-1994: (at time of landfall with landfall area) --------------------------- HURRICANE YEAR CATEGORY CENTRAL PRESSURE 1. " Labor Day " - FL Keys 1935 5 892 mb 2. Camille - LA/MS 1969 5 909 3. Andrew - SE FL 1992 4 922 4. Unnamed - FL Keys/S TX 1919 4 927 5. Unnamed - Lake Okeechobee, FL 1928 4 929 6. DONNA - FL Keys 1960 4 930 7. Unnamed - Galveston, TX 1900 4 931 8. Unnamed - Grand Isle, LA 1909 4 931 9. Unnamed - New Orleans, LA 1915 4 931 10. Carla - C TX 1961 4 931 10 Costliest USA (continental) hurricanes from 1900-1994: (adjusted to 1990 dollars - except for Andrew) ------------------------ HURRICANE YEAR CATEGORY DAMAGE (USA) 1. Andrew - SE FL/LA 1992 4 ~$25,000,000,000 2. Hugo - SC 1989 4 7,155,120,000 3. Betsy - FL/LA 1965 3 6,461,303,000 4. Agnes - NE U.S. 1972 1 6,418,143,000 5. Camille - LA/MS 1969 5 5,242,380,000 6. Diane - NE U.S. 1955 1 4,199,645,000 7. " New England " 1938 3 3,593,853,000 8. Frederic - AL/MS 1979 3 3,502,942,000 9. Alicia - N TX 1983 3 2,391,854,000 10. Carol - NE U.S. 1954 3 2,370,215,000 10 Deadliest USA (continental) hurricanes from 1900-1994: ------------------------ HURRICANE YEAR CATEGORY DEATHS 1. Unnamed - Galveston, TX 1900 4 6000+ 2. Unnamed - Lake Okeechobee, FL 1928 4 1836 3. Unnamed - Fl Keys/S TX 1919 4 600-900 4. " New England " 1938 3 600 5. " Labor Day " - FL Keys 1935 5 408 6. Audrey - SW LA/N TX 1957 4 390 7. Unnamed - NE U.S. 1944 3 390 8. Unnamed - Grand Isle, LA 1909 4 350 9. Unnamed - New Orleans, LA 1915 4 275 10. Unnamed - Galveston, TX 1915 4 275 ADDENDUM: Unnamed - LA - 1893 - 2000 Unnamed - SC/GA - 1893 - 1000-2000 Unnamed - GA/SC - 1881 - 700 *********************************** 23) What is Prof. Gray's seasonal hurricane forecast for this year and what are the predictive factors? Prof. Bill Gray at Colorado State University in Fort Collins, Colorado (USA) has issued seasonal hurricane forecasts for the Atlantic basin since 1984. Details of his forecasting technique can be found in Gray (1984a,b) and Gray et al. (1992, 1993, 1994). Landsea et al. (1994) also provides verifications of the first 10 years of forecasting. A quick summary of the components follows: * El Nino/Southern Oscillation (ENSO) - During El Nino events (ENSO warm phase), tropospheric vertical shear is increased inhibiting tropical cyclone genesis and intensification. La Nina events (ENSO cold phase) enhances activity. * African West Sahel rainfall - In years of West Sahel drought conditions, the Atlantic hurricane activity is much reduced - especially the intense hurricane activity (Landsea and Gray 1992). Wet West Sahel years mean a higher chance of low-latitude " Cape Verde " type hurricanes. This is also due to higher tropospheric vertical shear in the drought years, though there may also be changes in the structure of African easterly waves as well to make them less likely to go through tropical cyclogenesis. * Stratospheric quasi-biennial oscillation (QBO) - During the 12 to 15 months when the equatorial stratosphere has the winds blowing from the east (east phase QBO), Atlantic basin tropical cyclone activity is reduced. The east phase is followed by 13 to 16 months of westerly winds in the equatorial stratosphere where the Atlantic activity is increased. It is believed (but not demonstrated) that the reduced activity in east years is due to increased lower stratospheric to upper tropospheric vertical shear which may disrupt the tropical cyclone structure. * Caribbean sea level pressure anomalies (SLPA) - During seasons of lower than average surface pressure around the Caribbean Sea, the Atlantic hurricane activity is enhanced. When it is higher than average, the tropical cyclone activity is diminished. Higher pressure indicates either a weaker Inter-tropical Convergence Zone (ITCZ) or a more equatorward position of the ITCZ or both. * Caribbean 200 mb zonal wind anomalies (ZWA) - The 200 mb winds around the Caribbean are often reflective of the ENSO or West Sahelian rainfall conditions (i.e. westerly ZWA corresponds to El Ninos and West Sahel drought conditions). However, the winds also provide some independent measure of the tropospheric vertical shear, especially in years of neutral ENSO and West Sahel rainfall. For 1995, Dr. Gray issued a 6 month lead forecast in late November and a mid-April update. On June 7th, a revised forecast will be issued that more explicitly takes into account ENSO conditions and expected West Sahel rainfall. In early August, Dr. Gray will issue a final update (to correspond with the start of the active portion of the Atlantic hurricane season) that uses the Caribbean data, updated ENSO conditions, and June-July West Sahel rainfall. A verification of the forecasts will be given in late November. STATUS OF GRAY'S ATLANTIC 1944- Nov 30 Apr 13 Observed SEASONAL HURRICANE FORECAST 1994 1994 1995 FOR 1995 Mean Fcst. Fcst. =============================== Named Storms 9.3 12 10 0 Named Storm Days 46.1 65 50 0 Hurricanes 5.7 8 6 0 Hurricane Days 23.0 35 25 0 Major Hurricanes (Category 3-4-5) 2.2 3 2 0 Major Hurricane Days 4.5 8 5 0 Hurricane Destruction Potential 68.1 100 75 0 Factors for 1995: - QBO will definitely be in a west phase (ENHANCING) - West Sahel rainfall is expected to be near to above normal (NEUTRAL TO ENHANCING) - ENSO is questionable. It could go to a cold event, or it could even swing back to another El Nino. April and May data are crucial. (?) - Caribbean SLPA and ZWA are being calculated for April and May (?) Overall: Assessment as of mid-April was for near average conditions with a good deal of uncertainty. However, " near average " would still be substantially more activity than has been seen from 1991-1994... Details of this and previous previous forecasts are available over the WWW at: http://typhoon.atmos.colostate.edu/~thorson/forecasts/index.html Also available are what the current status of this year's hurricane season is progressing. ********************************** 24) What are those models that the Atlantic forecasters are talking about in the Inter-Governmental messages? (Contributed by Sim Aberson) A variety of hurricane track forecast models are run operationally for the Atlantic hurricane basin: (1) A statistical-dynamical model, NHC90 (McAdie 1991), uses geopotential height predictors from the Aviation model to produce a track forecast four times per day. The primary synoptic time NHC90 forecasts (00 and 12 UTC) are based upon 12 h old Aviation runs. A special version of NHC90, NHC90-LATE, is run at primary synoptic times with the current Aviation run, and is available a number of hours after NHC90. Both versions of NHC90 have been run operationally since 1990. (2) The Beta and Advection Model, BAM, follows a trajectory in the vertically-averaged horizontal wind from the Aviation model beginning at the current storm location, with a correction that accounts for the beta effect (Marks 1992). Three versions of this model, one with a shallow-layer (BAM-SHALLOW), one with a medium-layer (BAM-MEDIUM), and one with a deep-layer (BAM-DEEP), are run. The deep-layer version was run operationally for primary synoptic times in 1989; all three versions have been run four times per day since 1990. (3) A nested barotropic hurricane track forecast model (VICBAR) has been run four times daily since 1989. The primary synoptic time runs are run from current NMC analyses, the off-time runs are run from six hour old data (Aberson and DeMaria 1994). (4) A three-dimensional mesoscale model designed specifically for hurricane forecasting, the QLM (Quasi-Lagrangian Model), has provided forecasts at primary synoptic times (Mathur 1991). The QLM uses input data similar to that used by VICBAR and has been run since 1989. The QLM is to be retired soon. (5) The NMC Aviation model (Lord 1993) has been used for track forecasting since the 1992 hurricane season. (6) A triply-nested movable mesh primitive equation model developed at the Geophysical Fluid Dynamics Laboratory (Bender et al 1993), known as the GFDL model, has provided forecasts since the 1992 hurricane season. ********************************** REFERENCES ---------- Aberson, S.D., and M. DeMaria (1994): Verification of a Nested Barotropic Hurricane Track Forecast Model (VICBAR). _Mon. Wea. Rev._, 122, 2804-2815. Bender, M.A., R.J. Ross, R.E. Tuleya, and Y. Kurihara (1993): Improvements in tropical cyclone track and intensity forecasts using the GFDL initialization system. _Mon. Wea. Rev._, 121, 2046-2061. Black, P.G., (1992): Evolution of maximum wind estimates in typhoons. _ICSU/WMO International Symposium on Tropical Cyclone Disasters_, October 12-16, 1992, Beijing. Bureau of Meteorology (1977): _Report by of Meteorology on Cyclone Tracy, December 1974_. Bureau of Meteorology, Melbourne, Australia, 82 pp. Chan, J.C.L. (1985): Tropical cyclone activity in the Northwest Pacific in relation to the El Nino / Southern Oscillation phenomenon. _Mon. Wea. Rev._, 113, 599-606. Dong Keqin (1988): El Nino and tropical cyclone frequency in the Australian region and the Northwest Pacific. _Aust. Met. Mag._, 36, 219-225. Dunn, G.E. and B.I. Miller (1960): _Atlantic Hurricanes_, Louisiana State Univ. Press, Baton Rough, Louisiana, 377 pp. Dunnavan and Diercks (1980): An analysis of Sypertyphoon Tip (October 1979). _Mon. Wea. Rev._, 180, 1915-1923. Gray, W.M., W.M. Frank, M.L. Corrin, C.A. Stokes (1976): Weather modification by carbon dust absorption of solar energy. _J. Appl. Meteor._, 15, 355-386. Gray, W.M. (1984a): Atlantic seasonal hurricane frequency: Part I. El Nino and 30 mb quasi-biennial oscillation influences. _Mon. Wea. Rev._, 112, 1649-1668. Gray, W.M. (1984b): Atlantic seasonal hurricane frequency: Part II. Forecasting its variability. _Mon. Wea. Rev._, 112, 1669-1683. Gray, W.M., C.W. Landsea, P.W. Mielke, Jr., and K.J. Berry (1992): Predicting Atlantic seasonal hurricane activity 6-11 months in advance. _Wea. Forecasting_, 7, 440-455. Gray, W.M., C.W. Landsea, P.W. Mielke, Jr., and K.J. Berry (1993): Predicting Atlantic seasonal tropical cyclone activity by 1 August. _Wea. Forecasting_, 8, 73-86. Gray, W.M., C.W. Landsea, P.W. Mielke, Jr., and K.J. Berry (1994): Predicting Atlantic seasonal tropical cyclone activity by 1 June. _Wea. Forecasting_, 9, 103-115. Hebert, P.J., J.D. Jarrell, and M. Mayfield (1992): The deadliest, costliest, and most intense United States hurricanes of this century. _NOAA Tech. Memo. NWS NHC-31_, National Hurricane Center, Coral Gables, Florida, 39 pp. Holland, G.J. (1993): " Ready Reckoner " - Chapter 9, _Global Guide to Tropical Cyclone Forecasting_, WMO/TC-No. 560, Report No. TCP-31, World Meteorological Organization, Geneva. Holliday, C.R., (1973): Record 12 and 24 hour deepening rates in a tropical cyclone. _Mon. Wea. Rev._, 101, 112-114. Lander, M. (1994): An exploratory analysis of the relationship between tropical storm formation in the Western North Pacific and ENSO. _Mon. Wea. Rev._, 122, 636-651. Landsea, C.W. (1993): A climatology of intense (or major) Atlantic hurricanes. _Mon. Wea. Rev._, 121, 1703-1713. Landsea, C.W. and W.M. Gray (1992): The strong association between Western Sahelian monsoon rainfall and intense Atlantic hurricanes. _J. Climate_, 5, 435-453. Landsea, C.W., W.M. Gray, P.W. Mielke, Jr., and K.J. Berry (1994): Seasonal forecasting of Atlantic hurricane activity. _Weather_, 49, 273-284. Lord, S.J. (1993): Recent developments in tropical cyclone track forecasting with the NMC global analysis and forecast system. _Preprints of the 20th Conference on Hurricanes and Tropical Meteorology_, San Antonio, Amer. Meteor. Soc., 290-291. Marks, D.G. (1992): The beta and advection model for hurricane track forecasting. _NOAA Tech. Memo. NWS NMC 70_, Natl. Meteorological Center, Camp Springs, Maryland, 89 pp. Mathur, M.B. (1991): The National Meteorological Center's quasi- Lagrangian model for hurricane prediction. _Mon. Wea. Rev._, 119, 1419-1447. McAdie, C.J. (1991): A comparison of tropical cyclone track forecasts produced by NHC90 and an alternate version (NHC90A) during the 1990 hurricane season. _Preprints of the 19th Conference on Hurricanes and Tropical Meteorology_, Miami, Amer. Meteor. Soc., 290-294. Neumann, C.J. (1993): " Global Overview " - Chapter 1, _Global Guide to Tropical Cyclone Forecasting_, WMO/TC-No. 560, Report No. TCP-31, World Meteorological Organization, Geneva. Nicholls, N. (1979): A possible method for predicting seasonal tropical cyclone activity in the Australian region. _Mon. Wea. Rev._, 107, 1221-1224. Nicholls, N. (1992): Recent performance of a method for forecasting Australian seasonal tropical cyclone activity. _Aust. Met. Mag._, 40, 105-110. Novlan, D.J. and W.M. Gray (1974): Hurricane-spawned tornadoes. _Mon. Wea. Rev._, 102, 476-488. Pan, Y. (1981): the effect of the thermal state of eastern equatorial Pacific on the frequency typhoons over western Pacific. _Acta Meteor. Sin._, 40, 24-32 (in Chinese). Revell, C.G. and S.W. Goulter (1986): South Pacific tropical cyclones and the Southern Oscillation. _Mon. Wea. Rev._, 114, 1138-1145. Schroeder, T.A. and Z. Yu (1995): Interannual variability of central Pacific tropical cyclones. _Preprints of the 21st Conference on Hurricanes and Tropical Meteorology_, Amer. Meteor. Soc., Miami, Florida, 437-439. Simpson, R.H. and H. Riehl (1981): _The Hurricane and Its Impact_. Louisiana State Univ. Press, Baton Rouge (IBSN 0-8071-0688-7), 398 pp. Tuleya, R.E. and Y. Kurihara (1978): A numerical simulation of the landfall of tropical cyclones. _J. Atmos. Sci._, 35, 242-257. Wakimoto, R.M. and P.G. Black (1994): Damage survey of Hurricane Andrew and its relationship to the eyewall. _Bull. Amer. Meteor. Soc._, 75, 189-200. Weatherford, C. and W.M. Gray (1988): Typhoon structure as revealed by aircraft reconnaissance. Part II: Structural variability. _Mon. Wea. Rev._, 116, 1044-1056. Whittingham, H.E., (1958): The Bathurst Bay Hurricane and associated storm surge. _Aust. Met. Mag._, 23, 14-36. Willoughby, H.E. (1990): Temporal changes of the primary circulation in tropical cyclones. _J. Atmos. Sci._, 47, 242-264. Willoughby, H.E., J.A. Clos, and M.G. Shoreibah (1982): Concentric eye walls, secondary wind maxima, and the evolution of the hurricane vortex. _J. Atmos. Sci._, 39, 395-411. Willoughby, H.E., D.P. Jorgensen, R.A. Black, and S.L. Rosenthal (1985): Project STORMFURY: A scientific chronicle 1962-1983. _Bull. Amer. Meteor. Soc._, 66, cover and 505-514. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.