From bakonon@wsicorp.com Tue Sep 09 02:32:47 1997 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!zdc-e!super.zippo.com!lotsanews.com!howland.erols.net!newsfeed1-hme1!newsfeed.internetmci.com!192.48.96.123!in1.uu.net!147.81.244.14!newsreader.read.tasc.com!usenet From: "Boris A. Konon" Newsgroups: bit.listserv.wx-talk Subject: Re: Correction (was Wx Hype History) Date: Tue, 09 Sep 1997 02:32:47 -0400 Organization: WSI Corporation Lines: 10 Message-ID: <3414ED8F.4994@wsicorp.com> References: <970908194003_-30832233@emout16.mail.aol.com> NNTP-Posting-Host: met2.wsicorp.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0Gold (Win95; I) To: SAKABAKBRG@AOL.COM Xref: pigpen.csrlink.net bit.listserv.wx-talk:3071 A recon aircraft found a pressure of 919 mb and estimated winds close to 160 mph while Gloria was east of the Bahamas on Sept 24, 1985. When the first recon reached Hugo, it found a pressure of 918 mb and winds of 160 mph. Both were Cat 5 storms at one time, but not at landfall. Boris A. Konon WSI Meteorological Operations From padgett@EGLIN.AF.MIL Tue Sep 09 08:46:00 1997 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!zdc-e!super.zippo.com!lotsanews.com!newsfeed.ecrc.net!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!howland.erols.net!paladin.american.edu!auvm!EGLIN.AF.MIL!padgett Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU Newsgroups: bit.listserv.wx-talk X-Priority: 3 X-Mailer: Internet Mail Service (5.0.1458.49) Message-ID: <199709091243.HAA11272@postman.eglin.af.mil> Date: Tue, 9 Sep 1997 07:46:00 -0500 Reply-To: "Padgett, James G." Sender: WX-TALK General weather discussions and talk From: "Padgett, James G." Subject: Re: Correction Comments: To: Scott Kaplan Lines: 46 Xref: pigpen.csrlink.net bit.listserv.wx-talk:3078 >---------- >From: Scott Kaplan >To: Multiple recipients of list WX-TALK >Subject: Re: Correction >Date: Monday, September 08, 1997 6:41PM >Gloria was a Category 5 storm when it was approaching the Bahamas. It had >weakened to a category 3 Hurricane by the time it made landfall on central >Long Island. Again, Gloria was NOT a Cat. 5 hurricane. The highest winds reported operationally were (if memory serves me correctly) 130 kts (150 mph), but in post-analysis the max winds were reduced to 125 kts. The minimum central pressure reported was 919 mb, which does just sneak into the Cat. 5 pressure range, but those central pressure ranges that accompany the Saffir/Simpson category descriptions are just nominal average values that correspond to the max sustained wind criteria for each category. The max sustained wind/minimum central pressure relationship can vary significantly for individual storms. For instance, the pressure in Hurricane Opal dropped to 916 mb, but the max sustained wind was analyzed to be 130 kts. Granted, the media could have referred to Gloria as a Cat. 5 hurricane, but that would be just another example of mis-representation by the news media, an occurrence which is not all that rare. Indeed, Gloria was called the "Killer Hurricane of the Century" when it was far from any populated shores and hadn't affected anyone except the fishes and octopi!! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from WX-TALK send e-mail to LISTSERV@PO.UIUC.EDU with "unsub wx-talk" in the body of your message. For help with WX-TALK write chris@siu.edu or see http://www.inlink.com/~landmb/intro.html From webmaster@weatherguide.com Fri Sep 12 02:37:51 1997 From: "Paul Britton" Subject: Re: Ooo Baby! Check out Linda Newsgroups: sci.geo.meteorology,bit.listserv.wx-talk References: Organization: WeatherGuide Message-ID: <01bcbf46$88225aa0$317012ce@crc.concentric.net.concentric.net> X-Newsreader: Microsoft Internet News 4.70.1162 NNTP-Posting-Host: ppp10049.la.inreach.net Date: 12 Sep 97 06:37:51 GMT Lines: 20 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!mr.net!www.nntp.primenet.com!globalcenter1!news.primenet.com!nntp.primenet.com!news.maxwell.syr.edu!news-peer.sprintlink.net!news-pull.sprintlink.net!news-in-east.sprintlink.net!news.sprintlink.net!Sprint!208.25.48.5!news.inreach.com!ppp10049.la.inreach.net Xref: pigpen.csrlink.net sci.geo.meteorology:5120 bit.listserv.wx-talk:3090 Evening Michael, Boy, she sure is a beaut! Can't wait for 1km res imagery tomorrow! At any rate..the TPC has a few SST maps for you to look at. http://www.nhc.noaa.gov/gifs/pac_anal.gif http://www.nhc.noaa.gov/gifs/pac_anom.gif Michael=Schneider wrote in article ... > > > 75mph to 170mph/gusts to 210mph, in 24 hours. > > Not bad, girl, not bad at all. > > > Anyone have a current water temp chart for the EPAC? > From gtwister@wku.campus.mci.net Fri Sep 12 17:06:53 1997 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!zdc-e!super.zippo.com!lotsanews.com!feed1.news.erols.com!newsfeed1-hme1!newsfeed.internetmci.com!204.71.76.137!news.campus.mci.net!n-f-m From: gtwister@wku.campus.mci.net (George Gumbert III ) Newsgroups: sci.geo.meteorology,bit.listserv.wx-talk Subject: Re: Ooo Baby! Check out Linda Date: Fri, 12 Sep 1997 21:06:53 GMT Organization: CampusMCI Lines: 42 Message-ID: <3419aee3.20286054@news.campus.mci.net> References: <01bcbf46$88225aa0$317012ce@crc.concentric.net.concentric.net> <5vb06t$bp5$1@izvestia.its.unimelb.edu.au> Reply-To: gtwister@wku.campus.mci.net+NOSPAM+ NNTP-Posting-Host: s06-pm20.snaustel.campus.mci.net X-Newsreader: Forte Free Agent 1.11/16.235 Xref: pigpen.csrlink.net sci.geo.meteorology:5138 bit.listserv.wx-talk:3093 On 12 Sep 1997 08:58:05 GMT, blair@mullara.met.unimelb.EDU.AU (Blair Trewin) wrote: > >Given: > >(a) the aforementioned SST anomalies which mean water warm enough to >sustain a hurricane is further up the coast than usual. >(b) the extreme intensity of Linda at the moment, and >(c) its forecast track NW, with a trough off the west coast to push it >further east than it might otherwise be, > >what chance is there that this one might actually make it to >California? If it is ever going to happen, this would seem to be >the ideal scenario for it (and, given how unprepared the population >would be, I could imagine that even a category 1 could cause some >significant damage if it hit LA or San Diego). > >Anyone looking for disaster movie scripts? > >Blair Trewin > The closest example of this was on Sept. 25, 1939 when a tropical storm hit Southern Califonia. Although it had 50 mph/81 kmph winds (don't know if this was peak gusts or substained), the heavy rains caused flooding. 45 people died. Regards, George \/ \/ \/ \/ \/ \/ \/ \/ \/ "Gigantic wedge tornado!... multiple vortex!... couldn't ask for anything else!! Beautiful tornado!!!" Videographer/stormchaser Bob Prentice April 26, 1991 Red Rock, Oklahoma Remove +NOSPAM+ to reply via email From sebenste@GEOG.NIU.EDU Fri Sep 12 18:34:42 1997 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!zdc-e!super.zippo.com!lotsanews.com!news.maxwell.syr.edu!howland.erols.net!paladin.american.edu!auvm!GEOG.NIU.EDU!sebenste Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU Newsgroups: bit.listserv.wx-talk X-Sender: sebenste@taiga MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Message-ID: Date: Fri, 12 Sep 1997 17:34:42 -0500 Reply-To: "Gilbert L. Sebenste" Sender: WX-TALK General weather discussions and talk From: "Gilbert L. Sebenste" Subject: Hurricane overkill... Lines: 45 Xref: pigpen.csrlink.net bit.listserv.wx-talk:3092 I saw this from the Los Angeles/Oxnard, CA National Weather Service forecast office... FPUS3 KLAX 121615 SFDLAX STATE FORECAST DISCUSSION NATIONAL WEATHER SERVICE OXNARD CA 900 AM PDT FRI SEP 12 1997 NOTICE TO MEDIA...THE REMAINS OF HURRICANE LINDA MAY MOVE OVER SOUTHERN CALIFORNIA MONDAY. SOME OF THE MEDIA HAVE BEEN SAYING THAT HURRICANE CONDITIONS MAY AFFECT SOUTHERN CALIFORNIA. THIS IS NOT TRUE! ANY HURRICANE THAT APPROACHES THE SOUTHLAND WILL WEAKEN DRAMATICALLY BEFORE MAKING LANDFALL HERE. WHILE THE WINDS WILL NOT BE STRONG...WE ARE LOOKING AT THE POSSIBILITY OF A SIGNIFICANT RAIN EVENT...WITH THE POSSIBILITY OF FLASH FLOODING. THERE WILL BE HIGH SURF AND SEAS AS WELL. THIS IS THE PRIMARY THREAT FROM THIS SYSTEM. I STRESS AGAIN...THE FORECAST IS UNCERTAIN AT THIS TIME. IF THE SYSTEM DOES MOVE OVER SOUTHERN CALIFORNIA...THE PRIMARY THREAT IS FLASH FLOODING AND HIGH SURF AND SEAS. BE RESPONSIBLE...PLEASE DO NOT OVERDRAMATIZE THIS THREAT. A LOT OF ALARMED PEOPLE ARE CALLING THIS OFFICE. 12Z ETA/NGM IN. MDLS INITIALIZED OK XCP FOR TROPICAL CYCLONES. MRNG ZN UPDTS...NONE. ------------------------------------------------------------------- Gilbert ******************************************************************************* Gilbert Sebenste ******** Internet: sebenste@geog.niu.edu (My opinions only!) ***** Owner of the Storm Chaser Homepage/SCH Canada *** URL: http://taiga.geog.niu.edu/chaser/chaser.html ** SCH Canada URL: http://taiga.geog.niu.edu/chaser/canada * THE STORM MACHINE: http://taiga.geog.niu.edu/machine/ * Never rage against THE STORM MACHINE! * ******************************************************************************* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from WX-TALK send e-mail to LISTSERV@PO.UIUC.EDU with "unsub wx-talk" in the body of your message. For help with WX-TALK write chris@siu.edu or see http://www.inlink.com/~landmb/intro.html From rjhstorm@proaxis.com Tue Sep 09 02:11:58 1997 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!zdc-e!super.zippo.com!lotsanews.com!howland.erols.net!feta.direct.ca!newsfeed.direct.ca!news.he.net!supernews.com!Supernews69!not-for-mail From: rjhstorm@proaxis.com (rjhstorm) Newsgroups: sci.geo.meteorology Subject: Re: Q: What is frequency of exceeding hurricane windspeeds of 170 mph? Date: 9 Sep 1997 06:11:58 GMT Organization: Oregon Tornado Chasers Society Lines: 10 Message-ID: <5v2pbe$mkp$1@e3000.supernews.com> References: <34148e8c.0@news1.ibm.net> NNTP-Posting-Host: 23193@206.163.143.159 Mime-Version: 1.0 Content-Type: Text/Plain; charset=US-ASCII X-Newsreader: WinVN 0.99.7 Xref: pigpen.csrlink.net sci.geo.meteorology:5074 Interesting mathematcial probability analysis - but it fails to take into consideration the actual physical environment - under current climatological patterns and ocean temperatures, it is probably impossible to sustain 170mph winds as far north as Atlantic City. There have been no Cat 5 (155mph+) hurricanes north of the carolinas; Cat 5 hurricanes need 85F+ water, and that just isn't available in the mid atlantic in quanitites and coverage to keep 170 mph winds going.> > From rlk@shell1.tiac.net Tue Sep 09 09:51:52 1997 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!zdc-e!super.zippo.com!lotsanews.com!mr.net!wolverine.gi.net!usenet.bridge.com!abnormal.com!news.cmc.net!news.gv.tsc.tdk.com!hub.org!news.IAEhv.nl!Cabal.CESspool!bofh.vszbr.cz!nntprelay.mathworks.com!cam-news-hub1.bbnplanet.com!news.bbnplanet.com!news-feed1.tiac.net!news-master.tiac.net!news@tiac.net From: Robert Krawitz Newsgroups: sci.geo.meteorology Subject: Re: Q: What is frequency of exceeding hurricane windspeeds of 170 mph? Date: 09 Sep 1997 09:51:52 -0400 Organization: The Internet Access Company, Inc. Lines: 18 Message-ID: References: <34148e8c.0@news1.ibm.net> <5v2pbe$mkp$1@e3000.supernews.com> NNTP-Posting-Host: shell1.tiac.net X-Newsreader: Gnus v5.3/Emacs 19.34 Xref: pigpen.csrlink.net sci.geo.meteorology:5075 rjhstorm@proaxis.com (rjhstorm) writes: > Interesting mathematcial probability analysis - but it fails to take into > consideration the actual physical environment - under current climatological > patterns and ocean temperatures, it is probably impossible to sustain 170mph > winds as far north as Atlantic City. Just to make it even less likely, note that if the storm is offshore Atlantic City will be on the west side of the center (the weaker side assuming it's moving north, as it surely will be). If it makes landfall south of Atlantic City, even a few hours of overland passage will weaken it significantly. -- Robert Krawitz http://www.tiac.net/users/rlk/ Tall Clubs International -- http://www.tall.org/ or 1-888-IM-TALL-2 Member of the League for Programming Freedom -- mail lpf@uunet.uu.net From abuslik@ibm.net Tue Sep 09 21:45:55 1997 From: abuslik@ibm.net (Arthur Buslik) Newsgroups: sci.geo.meteorology Subject: Re: Q: What is frequency of exceeding hurricane windspeeds of 170 mph? Date: Wed, 10 Sep 1997 01:45:55 GMT Reply-To: abuslik@ibm.net References: <34148e8c.0@news1.ibm.net> <341539F3.8051494C@miningco.com> X-Newsreader: Forte Free Agent 1.0.82 NNTP-Posting-Host: 166.72.74.95 Message-ID: <3415fbf0.0@news1.ibm.net> Lines: 97 Path: pigpen.csrlink.net!news-out.microserve.net!news-in.microserve.net!mr.net!news-out.communique.net!communique!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed1-hme1!newsfeed.internetmci.com!165.87.194.248!newsm.ibm.net!ibm.net!news1.ibm.net!166.72.74.95 Xref: pigpen.csrlink.net sci.geo.meteorology:5087 The reference on the Weibull distribution fitting the data is: NBS Building Science Series 124, "Hurricane Wind Speeds in the United States", by Martin E. Batts, Martin R. Cordes, Larry R. Russel, James R. Shaver, and Emil Simiu, issued May 1980. When I wrote my original posting yesterday, I had not received a copy of the report yet, and I had just seen it referenced. I now have a copy of the report, and it is possible to use the information in the report to determine the parameters of the Weibull distribution for Atlantic City. The report uses a Weibull "tail length" parameter gamma of 4. I thought at first the "tail length" parameter was the shape parameter eta in the Weibull complementary cumulative distribution function G=exp(-u^eta), but upon examination of a graph where the authors plot the reduced variate, (-lnG)^(1/eta), against the wind speed to demonstrate that the distribution is well fitted by a Weibull distribution, I found that for the tail length parameter of 4, eta was 11. I conjecture that eta=3*gamma - 1, but I have no idea why gamma is defined that way. (Incidentally, the graph shows that the plot of the reduced variate against the wind speed is linear, so that the Weibull is a good fit). In any event, Atlantic City corresponds to his milepost 2450, approximately, and at that point he obtains a frequency of exceeding wind speeds of 125 mph of 5E-4 per year (2000 year return period), and a frequency of exceeding wind speeds of 90 mph of .01 (100 year return period). This is fitted by a Weibull distribution with eta=11, and u given by: u=(v+669)/660, where v is the wind speed. For v=170 mph, one obtains 8E-7 per year , or a return period of 1.25 million years. For v=155 mph, one obtains 1E-5, or a return period of one hundred thousand years, more than a factor of 10 higher. The report notes that "owing to the possible inapplicability of the physical models used in this work at locations north of Cape Hatteras, estimated hurricane wind speeds given for these locations should be viewed with considerable caution". Incidentally, the problem with using the empirical distribution is that there is not enough data, one is interested in very long return periods. The referenced report uses a combination of physical models and data, and finds that the output is well fitted by a Weibull distribution. Arthur Buslik Joseph Bartlo wrote: >Arthur Buslik wrote: >> My understanding is that hurricane wind speeds do not follow a >> Type I extreme value distribution (or, for that matter, a reverse >> Weibull distribution), but that they follow a Weibull >> distribution. If I had estimates of the parameters for the >> distribution, then I would be finished (since I would fearlessly >> assume that the distribution is still valid far out in the tails, >> at a wind speed of 170 mph.) But I don't have the parameters. >> Can anyone help here? >Did a study indicate this, or is it a hunch ? I.e., I don't >think any probability distribution should be very nearly like >observed distribution, though some may approximately mimic >it. A Weibull distribution varies greatly as parameters >you mention do, so you can probably find one which portrays >current hurricane strength distribution, which will probably >change. >> 1. I know that hurricanes will be less likely at Atlantic City >> than, say, below the 35th parallel. However, given that a >> hurricane wind speed is greater than 85 mph, is the probability >> that it is, say, greater than 155 mph, more or less site >> independent? That is, is >> >> Pr{V >155 mph | V > 85 mph, at site a} >> >> more or less independent of which site is chosen as site a? >Conditional probability of a Cat 5 hurricane if a hurricane >occurs greatly decreases N of the tropics, as was mentioned >(I had a hunch that someone might post something regarding >weather ;) ). Considering return periods of a million years, >climate changes are the most relevant aspect. Several ice >ages and interglacial periods are likely, during which typical >water temps off the NJ coast might be as in the Caribbean now >(perhaps not that extreme). Long-term climate change studies >are most relevant for answering your question. >Joseph