The Most Intense Tropical Storms on Earth Yet Recorded
The Most Intense Tropical Storms on Earth Yet Recorded
On September 15th Super Typhoon Sanba reached its maximum intensity with 150-knot (175 mph) winds and a central pressure of 900 mb (26.58”) according to the Tropical Cyclone Information center at the Japanese Meteorological Agency. It was the strongest tropical storm on earth since Typhoon Megi bottomed out at 885 mb (26.14”) in the open waters of the Western Pacific on August 17, 2010. Herein is a short blog listing all the known tropical storms on record (in the world) that have measured central pressures of 900 mb or lower.
A perfect storm. Super Typhoon Sanba reached ‘perfect’ tropical storm genesis on September 15th this month. The outline of the Philippine Islands can be seen on the left of the image. Photo from NASA by the MODIS instrument aboard NASA's Aqua satellite.
The caveats to these lists
We have a fairly good record for the history of intense tropical storms in the North Atlantic Basin (which includes the Caribbean and Gulf of Mexico) going back to around 1900 (and even earlier) because of the great amount of ship traffic that has been traversing the Atlantic between Europe and the Americas for centuries, and then, beginning in 1970, weather satellites devoted to observing the weather over the Atlantic Ocean. However, this (a long observation period of record) cannot be said for the other ocean basins of the world where tropical storms frequently form.
By far, the most active region in the world for tropical storm formation is the Western Pacific Ocean (both North and South) where throughout history devastating typhoons have wreaked havoc from Australia to Japan. We know the 1940s were a particularly active decade in the Pacific due to the damage the typhoons caused to both the American and Japanese naval fleets during World War Two.
However, it was not until 1959 with the establishment of the Joint Typhoon Warning Center (JTWC) by the U.S. Navy in Guam that a dedicated effort was made to begin monitoring tropical storm activity in the West Pacific. Actually, the center was first formed in 1945 following Typhoon Cobra that, on December 18th 1944, sank dozens of U.S. war ships in the Pacific Ocean a few hundred miles east of the Philippines resulting in the loss of 790 U.S. Navy personnel: the worst U.S. military naval loss due to a single weather in history and also known as Halsey's Typhoon named a after Admiral William 'Bull' Halsey commander of the Third Fleet at the time.
The aircraft carrier USS Langley (CVL-27) lists dangerously during Typhoon Cobra east of the Philippines in December 1944. Some 790 U.S. sailors lost their lives during this storm, mostly when three destroyers, the USS Hull, USS Monaghan, and USS Spence capsized and sank accounting for 775 of the fatalities. Photo from Wikipedia file.
In 2000, the JTWC moved its headquarters to Pearl Harbor, Hawaii from where it now operates.
It should also be noted that the methods of determining an individual tropical storm’s minimum pressure have changed over time. In the Atlantic Basin prior to 1950 the pressures were measured by ships or surface stations. Since then the Hurricane Hunter aircraft have flown into storms and made pressure measurements by dropsondes. In the Pacific aircraft were also used from 1959 to 1987 when a new less costly (in dollars and lives) method came into use using the so-called Knaff-Zehr wind-pressure relationship.
Approximately 25 lives were lost during the years the U.S. Navy typhoon hunters made their passes between 1945-1987. The six above were investigating Typhoon Bless in October 1974 when their aircraft disappeared on a flight mission. From JTWC archives 1974.
This is a method of determining central air pressure by correlation to estimated maximum wind surface speeds. Consequently, there is some disagreement about how low a storm’s actual pressure may be between various agencies like the JTWC, the Tropical Cyclone Information arm of the Japanese Meteorological Agency, or the Australian Bureau of Meteorology. For instance, the JTWC estimated Typhoon Sanba’s lowest pressure at 911 mb vs. the 900 mb estimated by the Japanese Met. Service. The Japanese estimate seems closer to reality given Sanba’s peak sustained winds of 175 mph.
Aside from the Pacific and Atlantic, even less (so far as storm details like central barometric pressure) is known about historic cyclones that have occurred with regularity in the Indian Ocean region, especially the Bay of Bengal. Recently, beginning in 2003, the JTWC has undertaken observations for this region as well.
So the bottom line is that good statistics for the Atlantic Basin go back to 1900, for the W. Pacific Ocean to 1959, and for the Indian Ocean to 2003 (aside from land-based measurements).
Wind Speeds
The winds of these storms are mostly estimated but virtually every storm with a pressure of 900 mb or less will produce maximum sustained winds of 140 knots (160 mph) or higher. Wind gusts of up to and over 200 mph have been measured by surface sites as well. The most intense storm of all, Typhoon Tip, saw a barometric pressure reading made by aircraft at 870 mb (25.69”) and sustained surface winds of 170 knots (195 mph). Some comments in the JTWC annual summary for 1979 can be read here from the their summary report in 1979:
Best Typhoon photo
An intense typhoon struck Polynesia’s Artua Atoll in the South Pacific during 1983 forcing the evacuation of the island’s residents. I've seen few clear images that have so well captured an evacuation from a perilous situation as this one image. Photo by Philippe Mazellier.
The Tables
Since 1959 there have been 108 tropical storms worldwide whose minimum central barometric pressure has fallen to 900 mb (26.58”)or less that we are aware of. Prior to 1959 there are 12 other known cases of such storms. Of the 120 known such storms 108 have formed in the Western Pacific Ocean (98 in the Northwestern Pacific and 10 in the Southwestern Pacific). Only 5 tropical storms of this intensity are known to have occurred in the Atlantic Basin (including the Caribbean and Gulf of Mexico).
The past 6 years (since 2006) have seen a period of relative quiet so far as these monster tropical storms are concerned. Prior to Super Typhoon Sanba this month, there has been only one other 900 mb or stronger storm recorded on earth: Typhoon Megi in 2010. The 1990s was the decade with the most such storms with 1997 the single most active year with an amazing 10 such storms.
Here are the ‘Top Five’ strongest storms on record (so far as central pressure is concerned) by region:
NOTE: Hurricane Rita's pressure has been officially revised to 895 mb not 897 mb. Thanks to WU commentator '1900Hurricane' for the heads up about Rita!
Below is a comprehensive list of every known tropical storm in the world to have reached (or estimated to have reached) a central sea-surface barometric pressure reading of 900 mb (26.58”) or lower. This list has been culled from many sources although the JTWC database has provided the bulk of the information (since the vast number of such storms have occurred in the West and South Pacific Ocean). For the sake of clarity I have not included the actual day of each storms maximum intensity although I have that information for those who might be interested:
LOWEST BAROMETRIC PRESSURES EVER MEASURED IN TROPICAL STORMS WORLDWIDE
(900 mb or lower) as of September 2012
**RANK/PRESSURE LOCATION DATE NAME
1) 870 (25.69) W. Pacific 1979 Tip
2) 872 (25.75) W. Pacific 1997 Joan
872 (25.75) W. Pacific 1997 Ivan
872 (25.75) W. Pacific 1992 Gay
3) 876 (25.86) W. Pacific 1983 Forrest
876 (25.86) W. Pacific 1975 June
4) 877 (25.89) W. Pacific 1973 Nora
877 (25.89) W. Pacific 1958 Ida
5) 878 (25.92) W. Pacific 2000 Damrey
878 (25.92) W. Pacific 1998 Zeb
878 (25.92) W. Pacific 1997 Keith
878 (25.92) W. Pacific 1992 Yvette
878 (25.92) W. Pacific 1978 Rita
6) 879 (25.95) W. Pacific 2004 Chaba
879 (25.95) S. Pacific 2002 Zoe
879 (25.95) W. Pacific 2001 Faxai
879 (25.95) W. Pacific 1995 Angela
879 (25.95) W. Pacific 1984 Vanessa
879 (25.96) Australia region 2006 Monica
7) 880 (26.01) W. Pacific 1966 Kit
8) 882 (26.05) Caribbean 2005 Wilma
882 (26.05) W. Pacific 1961 Nancy
882 (26.05) W. Pacific 1961 Violet
9) 884 (26.11) W. Pacific 1971 Irma
10)885 (26.14) W. Pacific 2010 Megi
885 (26.14) W. Pacific 2004 Dianmu
885 (26.14) W. Pacific 2003 Maemi
885 (26.14) W. Pacific 1991 Yuri
885 (26.14) W. Pacific 1990 Mike
11)886 (26.16) W. Pacific 1954 Ida
886 (26.16) W. Pacific 1951 Marge
886 (26.16) W. Pacific 1900 SS Arethusa
12)887 (26.18) W. Pacific 1979 Judy
887 (26.18) W. Pacific 1927 SS Sapoeroea
13)888 (26.22) Caribbean 1988 Gilbert
888 (26.22) W. Pacific 1983 Abby
14)890 (26.27) W. Pacific 1980 Wynne
890 (26.27) W. Pacific 1969 Elsie
890 (26.27) W. Pacific 1967 Gilda
15)891 (26.30) W. Pacific 2003 Lupit
891 (26.30) W. Pacific 1990 Flo
891 (26.30) W. Pacific 1987 Betty
891 (26.30) W. Pacific 1987 Nima
891 (26.30) W. Pacific 1959 Joan
891 (26.30) Bay of Bengal 1833 SS Duke of York
16)892 (26.35) S. Pacific 2005 Olaf
892 (26.35) W. Pacific 1997 Isa
892 (26.35) W. Pacific 1997 Ginger
892 (26.35) W. Pacific 1992 Elsie
892 (26.35) W. Pacific 1991 Ruth
892 (26.35) Long Key, Florida 1935 Labor Day Storm
(this is the lowest pressure ever observed at a land station on earth)
17)893 (26.37) W. Pacific 1981 Elysie
893 (26.37) W. Pacific 1973 Patsy
18)894 (26.39) W. Pacific 1964 Sally
19)895 (26.39) Gulf of Mexico 2005 Rita
895 (26.39) Indian Ocean 2004 Gafilo
895 (26.39) W. Pacific 1982 Mac
895 (26.42) W. Pacific 1976 Louise
895 (26.42) W. Pacific 1971 Amy
895 (26.42) W. Pacific 1970 Hope
20)896 (26.45) W. Pacific 1983 Marge
896 (26.45) W. Pacific 1959 Vera
21) 897 (26.48) W. Pacific 1985 Dot
897 (26.48) W. Pacific 1969 Viola
897 (26.48) W. Pacific 1962 Karen
22)898 (26.51) S. Pacific 2006 Glenda
898 (26.51) W. Pacific 2005 Nabi
898 (26.51) S. Pacific 2005 Bento
898 (26.51) S. Pacific 2005 Percy
898 (26.51) W. Pacific 2005 Haitang
898 (26.51) S. Pacific 2004 Heta
898 (26.51) W. Pacific 2004 Nida
898 (26.51) W. Pacific 2004 Ma-On
898 (26.51) S. Pacific 2003 Kalunde
898 (26.51) S. Pacific 2003 Inigo
898 (26.51) W. Pacific 2002 Harry
898 (26.51) W. Pacific 2001 Podul
898 (26.51) W. Pacific 2000 Saomai
898 (26.51) W. Pacific 2000 Bilis
898 (26.51) W. Pacific 1999 Bart
898 (26.51) W. Pacific 1997 Oliwa
898 (26.51) W. Pacific 1997 Winnie
898 (26.51) W. Pacific 1997 Rosie
898 (26.51) W. Pacific 1997 Nestor
898 (26.51) W. Pacific 1996 Dale
898 (26.51) W. Pacific 1996 Sally
898 (26.51) W. Pacific 1996 Herd
898 (26.51) W. Pacific 1996 Eve
898 (26.51) W. Pacific 1995 Ward
898 (26.51) W. Pacific 1995 Oscar
898 (26.51) W. Pacific 1995 Kent
898 (26.51) W. Pacific 1994 Doug
898 (26.51) W. Pacific 1993 Ed
898 (26.51) W. Pacific 1991 Walt
898 (26.51) W. Pacific 1990 Owen
898 (26.51) W. Pacific 1990 Page
898 (26.51) W. Pacific 1989 Nima
898 (26.51) W. Pacific 1989 Elsie
898 (26.51) W. Pacific 1989 Gordon
898 (26.51) W. Pacific 1989 Andy
898 (26.51) W. Pacific 1988 Nelson
898 (26.51) W. Pacific 1987 Lynn
898 (26.51) W. Pacific 1987 Holly
898 (26.51) Indian Ocean 1982 Damia
898 (26.51) W. Pacific 1979 Hope
898 (26.51) W. Pacific 1971 Nadine
23)899 (26.54) Caribbean 1980 Allen
24)900 (26.58) W. Pacific 2012 Sanba
900 (26.58) Australia region 2003 Inigo
900 (26.58) Australia region 1999 Gwenda
900 (26.58) S. Pacific 1998 Ron
900 (26.58) S. Pacific 1998 Susan
900 (26.58) E. Pacific 1997 Linda
900 (26.58) W. Pacific 1986 Progy
900 (26.58) W. Pacific 1975 Elsie
900 (26.58) W. Pacific 1957 Virginia
900 (26.58) W. Pacific 1957 Lola
900 (26.58) W. Pacific 1957 Hester
900 (26.58) W. Pacific 1954 Pamela
900 (26.58) W. Pacific 1953 Tess
** Ranking has been made chronologically, with more recent measurements ranking first
Christopher C. Burt
Weather Historian
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Updated: 05:30 GMT le 29 septembre 2012
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After the Azizia de-certication, what might the new African heat record be?
After the Azizia de-certication, what might the new African continental heat record be?
Following the WMO rejection of Al Azizia, Libya as the location where the world’s hottest temperature was measured, the WMO concluded that the new world record for such has fallen by default to Greenland Ranch, Death Valley and its 134°F (56.7°C) on July 10, 1913. But what is the new African continental heat record? For the sake of convenience the WMO has, at least temporarily, established the 55°C (131°F) reading made at Kebili, Tunisia on July 7, 1931 as the current new African record pending certification.
Unfortunately, the Kebili reading will probably end up just as suspicious as the Azizia record under close examination. A larger problem looms when we start to look at the large number of excessive extreme heat records reported from North Africa between 1885 and the Second World War (1942). Aside from Kebili, there have been a number of 130°F+ (54°C) temperatures reported during this period at half a dozen or so different locations in Mali, Algeria, Tunisia, and Libya. Yet following the Second World War to the present, the hottest verified temperature measured at any location in North Africa has only been 50.7° (123.3°C) at Smara (also known as as-Samarah), Western Sahara (claimed by Morocco) on July 13, 1961.
The Kebili, Tunisia record of 55°C (131.0°F)
Kebili is one of the oldest oasis in north Africa and is now a popular tourist resort, lying at it does on the edge of the Saharan Desert near seal level about 40 miles east of the El Hamma du Jend Depression which is 23 meters (75 feet) below sea level.
A map of Tunisia showing the location of Kebili. The blue area is the dry lake of Chott El Jerid.
Temperature records have been kept here from 1901-1939, 1949-1953, and 2000-2012 so far as I have able to discern. The French colonial authorities of the Service Meteorologique de Tunis maintained the older records. A portion of the original data logs for this early period is in the NCDC archives and I looked at the POR of 1907 to 1932. Like Azizia, Kebili is subject to the foehn-like wind phenomena know as a Ghibili. Extreme 50°C+ temperatures were recorded on July 17, 1910: 53.0°C (127.4°F), July 1925: 50.0°C (122.0°F), August 1926: 50.8°C (123.4°F), July 1927: 54.0°C (129.2°F), and of course July 1931 with 55.0°C (131°F). No further 50°C+ temperatures were measured after 1931. However, during the 2000-2012 POR the maximum temperature measured (using modern equipment) has been 48.5°C (119.3°F) on July 26, 2005. So this certainly throws suspicion on the older Kebili records.
A recent photograph of one of the desert resorts at Kebili, Tunisia. Photographer unknown. Photo from Tunisian tourism site.
Once again, like Azizia, Kebili appears to be another place in North Africa recording astonishing temperatures during the period of colonial record prior to pre-WW II.
Unfortunately, there will be very little information available to investigators to authenticate these old measurements since at the time they did not represent potential world or continental records so we do not have a long history of published discussions or previous investigations (ala Fantoli for Azizia) to look at.
Other 53°C+ (127.4°F) North African temperature reports
TUNISIA
Another site in Tunisia, Ben Gardene (or Ben Guerdane) also reported a 55°C (131°F) reading at some undetermined time in its early POR according to a mention in the World Survey of Climatology: Vol. 10, Climates of Africa’ on p.42. Ben Gardene is on the Mediterranean coast near the border of Libya. Its coastal location would seem to preclude such a phenomenal temperature. Another site in the Tunisian records, Dehibat, reported a temperature of 54.8°C (130.6°F) in July 1927.
A photograph of a French outpost at Dehibat taken in 1957. Photo by Tom Killian.
And yet another Tunisian site, Gafsa, reported 52.8°C (127°) during some July between 1901 and 1950. The warmest temperature measured in modern records in Tunisia is 50.1°C (122.2°F) at El Borma (al-Burmah) on July 26, 2005.
LIBYA
Ghadames, Libya has also reported a 55°C (131°F) temperature at some point during its POR of 1924-1942. More recently, a 54.2°C (129.6°F) reading in June 1975 and a 54.0°C (129.2°F) in May 1969 were recorded but found to be in error (in both cases the figures in the logs had been transposed, it was actually 45.2°C (113.4°F) in 1969 and 45.0°F (113°F) in 1975). Ghadames modern heat record is 48.4°C (119.1°F) in July 1977. The hottest temperature measured in Libya during the modern era is 50.2°C (122.4°F) at Zuara in June 1995.
ALGERIA
In Algeria there is an ancient report of a 53°C (127.4°F) temperature occurring on August 27, 1884 at Ouargla. The U.K. Met Office publication Tables of Temperature, Relative Humidity and Precipitation for the World: Part 4; Africa includes a maximum temperature of 127°F (52.8°C) occurring at Ouargla in July sometime between 1925 and 1950. Algeria’s modern heat record is 50.6°C (123.1°F) at In Salah on July 12, 2002.
A copy of the French weather report for Algeria on August 27, 1884. There is no mention of the 53°C reading here or in any of the following daily or month’s reports. Image from ‘Bulletin Meteorologique du Gouvernment de l’Algerie’, Paris, 1877-1968 (retrieved via NOAA’s Central Library of Foreign Climate Data).
MALI
Timbuktu and Araouane, both in Mali and in the Saharan Desert have recorded temperatures of 130°F (54.4°C) in the past according to various sources. For Araouane, this happened in a July sometime between 1930-1940 according to the U.K. Met office publication mentioned above. The Timbuktu source for their supposed 130°F reading is unknown although records date back to 1896 here. No official temperature above 47.8°C (118.0°F)-set in May 1958-has ever been measured here. Mali’s modern heat record is 48.2°C (119.0°F) at Gao in May 1988.
EGYPT
Egypt’s official heat record is 51.0°C (123.8°F) measured by British colonial officials at Aswan on July 4, 1918. This could well be the new African continental heat record if we give the benefit of the doubt to the British colonial observers at that early time. At least there are probably some good sources to investigate this record in the British archives which cannot be said about the other European colonial powers of that era in North Africa. However, if we discount this record as well, then the modern Egyptian record of 50.3°C (122.5°F) at Kharga Oasis on June 9, 1961 would be Egypt’s national heat record.
The log sheet for the daily climate report for Egypt on July 5, 1918 showing the 51°C temperature recorded at Aswan on July 4th (date on sheet is July 5th but the daily temp reports refer to the day before). Table from British colonial archive.
Conclusion
A brief recap of the various locations in North Africa reporting temperatures of 53°C (127.4°F) or above:
55°.0°C (131.0°F) Kebili, Tunisia on July 7, 1931: Source ‘Service Meteorologique de Tunis’. Poor correspondence between colonial and modern records at this site.
55.0°C (131.0°F) Ghadames, Libya in June sometime between 1924-1942 : Source ‘Servizio Meteorologico, Rome’. Exact date unknown. Poor correspondence between colonial and modern records with the exception of two 54°C+ temperatures in 1969 and 1975 which are known transcription errors.
55°C (131.0°F) Ben Gardene, Tunisia date unknown: Source ‘World Survey of Climatology: Vol. 10, Climates of Africa’ and also probably ‘Service Meteorologique de Tunis’. No details known about this record, needs further research. Suspicious figure for a coastal location.
54.8°C (130.6°F) Dehibat, Tunisia in July 1927: Source ‘Service Meteorologique de Tunis’. Little further known about this site or record.
54.4°C (130.0°F) Araouane, Mali in July sometime between 1930-1940: Source ‘Service Meteorologique de Dakar’. No specific date yet found for this. No modern weather station maintained here.
54.4°C (130.0°F) Timbuktu, Mali date and source unknown. This record can be dismissed outright. The city has quite a long POR and no temperature above 118-119°F has ever been officially recorded here.
53.0°C (127.4°F) Ouargla, Algeria on Aug. 27, 1884: Source ‘Bulletin Meteorologique du Gouvernment de l’Algerie’? I looked through the data for Algeria in August and September 1884 and saw no mention of this figure or of Ouargla.
As can be seen from the data above, it would be daunting for WMO investigators to sort through all these contenders and come to any definitive conclusion. Perhaps the best way to approach this is via the asterisk (*) method for unverified old colonial records on the one hand versus another list of records from the modern era where we know for a fact the readings were made under standard conditions using modern equipment. The hottest verified modern temperature measured at any location in North Africa has only been 50.7° (123.3°C) at Smara (also known as as-Samarah), Western Sahara (claimed by Morocco) on July 13, 1961.
Of course, it should be mentioned that there are most likely parts of North Africa that have recoded higher temperatures at some point in recent history than those listed above, but these locations have never had a weather station to officiate such.
KUDOS: Khalid Ibrahim El Fadli of the Libyan National Meteorological Center (LNMC) for details concerning the Ghadames, Libya temperature records. Maximiliano Hererra for modern African national heat records.
REFERENCES:
‘Tables of Temperature, Relative Humidity and Precipitation for the World: Part IV, Africa, the Atlantic Ocean South of 35°N and the Indian Ocean’, U.K. Meteorology Office, 1967.
‘World Survey of Climatology: Vol .10, Climates of Africa’, Elsevier Publishing, 1972
‘Bulletin Meteorologique du Gouvernment de l’Algerie’, Paris, 1877-1968
‘Service Meteorologique de Dakar’ Memento No. 7A, Moyennes. Rufisque, 1941 for Araouane, Mali data.
‘Service Meteorologique de Tunis’ Regence de Tunis, Protectorat Francais, 1907-1932 (NOAA Central Library Foreign Climate Data).
Christopher C. Burt
Weather Historian
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Updated: 03:26 GMT le 23 septembre 2012
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World Heat Record Overturned--A Personal Account
World Heat Record Overturned--A Personal Account
Almost two years after my October 8, 2010 wunderground blog post, Questions Concerning the World Record Temperature of 58°C (136.4°F) at Al Azizia, Libya on September 13, 1922, the World Meteorological Organization (WMO) has come to the conclusion that the record, in fact, was invalid. Here is a personal account of how this decision came to be. The narrative below is adapted from a blog post I have written for the Bulletin of the American Meteorological Society (BAMS).
A photograph of the trading post at Al Azizia, Libya taken in 1923. The photo was taken from the Italian military fort located on a small hill just south of the trading post. It was at this fort that the temperature of 58°C (136.4°F) was observed on Sept. 13, 1922 (Used with permission from the family of Gen. Enrico Pezzi).
As any weather aficionado can avow, Earth's most iconic weather record has long been the legendary all-time hottest temperature of 58°C (136.4°F) measured on September 13, 1922 at Al Azizia, Libya (also called El Azizia, there are many variant spellings). It is a figure that has been for meteorologists as Mt. Everest is for geographers. For the past 90 years, no place on Earth has come close to beating this reading from Al Azizia, and for good reason--the record is simply not believable.
In early March 2010, I was included in an email loop concerning questions about this record. The email discussion participants at that time included Maximiliano Herrera, an Italian temperature researcher and climatologist based in Bangkok, Piotr Djakow, a Polish weather researcher, and Khalid Ibrahim El Fadli, director of the climate department at the Libyan National Meteorological Center (LNMC) in Tripoli.
Previous to this discussion, I had generally accepted the Libyan world record as acceptable, although suspicious. The figure had been around for 90 years, and two previous studies by Amicare Fantoli (who was the man responsible for verifying the record in 1922) had more or less substantiated the extreme 58°C figure.
However, Piotr produced a chart of the monthly temperature amplitudes at Azizia for each September from 1921 - 1940, and this chart raised an alarm so far as the validity of the Aziza record was concerned. This was the first time that I began to really think something was not right about the record.
A chart showing the average monthly temperature amplitudes (difference between daily minimum and daily maximum temperatures) for Al Azizia during the month of September from 1919 - 1940. In 1927, the station was moved from the military fort on the hill to the town below and placed in civilian hands. (Chart produced by Piotr Djakow).
In September 2010, Weather Underground hired me as their Weather Historian, proposing that I write a weekly blog on extreme weather events and records. I decided that one of my first blogs should on the Al Azizia record (in fact it was the third blog I wrote for WU).
I was intrigued that El Fadli was skeptical of the Al Azizia 58°C figure, and requested more data. El Fadli’s enthusiastic and gracious response (to provide all and any weather data I might be interested in) was beyond my expectations. Past experience had shown me that many national weather bureaus consider their data proprietary and/or subject to excessive fees for access.
With El Fadli’s data on hand and after researching all (to me at the time) known other references concerning the Al Azizia event, I posted a blog on wunderground.com reflecting my findings on October 8, 2010. I forwarded a copy of this to Dr. Randy Cerveny, a professor at Arizona State University (ASU) and co-Rapporteur of climate and weather extremes for the World Meteorological Organization (WMO).
It should be noted that without the credibility of Weather Underground as my sponsor, Dr. Cerveny probably would not have taken the blog seriously. After all, many people in the past have questioned the validity of this record both in published works and on the Internet.
In any case, Randy picked up the ball and created an ad-hoc evaluation committee for the World Meteorological Organization to evaluate the record for the WMO Archive of Weather and Climate Extremes (http://wmo.asu.edu/). After this positive response from Randy, I asked El Fadli if Libya officially accepted the Azizia figure. He responded that they did not. Since records like this are, to a degree, the provenance of national interest and El Fadli responded that Libya did not officially accept the colonial-era data from Azizia (measured by Italian authorities at that time in Tripolitania), this became the catalyst to launch an official WMO investigation.
This would be an unprecedented investigation for this WMO extreme records evaluation committee. Rehashing old records is not the WMO Archive’s primary objective, which is to verify new potential records. As Dr. Tom Peterson of the US National Climate Data Center and President of the WMO’s Commission on Climatology (of which the Archive is a part), put it:
“To be honest, I was reluctant to reopen this question because other people had looked at the record in the past and it had been so widely accepted. I was particularly afraid that it would be an uncertain subjective opinion as to whether it was a bit off or not.”
Nevertheless, the investigation was approved and on February 8, 2011 an international team of climate experts was assembled (eventually 13 atmospheric scientists in all) by Randy. The official investigation began.
Amazingly, El Fadli had just uncovered a key document: the actual log sheet of the observations made at Azizia in September 1922 (see illustration further below). The log sheet clearly illustrated that a change of observers had occurred (as was evidenced by the hand written script) on September 11, 1922, just two days prior to the ostensible record temperature of 58° on September 13th. Furthermore, the new observer had interchanged the Tmin columns with the Tmax columns.
A copy of the log sheet from El Azizia for September 1922 found by El Fadli in January 2011. Image courtesy of the Libyan National Meteorological Center (LNMC).
Also, beginning on September 11th the Azizia maximum daily temperature records began to exceed by 7°C, on average, the other four stations reporting from northwest Libya (Tripolitania) at that time. That trend continued for the rest of the month (with a couple of days of missing data), and into October 1922.
A graph comparing the daily maximum temperatures observed in September 1922 at the five meteorological stations that existed in Tripolitania (northwestern Libya) at that time. There was an observer change at El Azizia beginning September 11th. (Graphic produced by Jim Petit).
Just as this key discovery (the finding of the original log sheet) was made, the Libyan revolution broke out. On February 15, 2011, we received the last message from El Fadli prior to the revolution. Col. Gaddafi, the leader of Libya, had shut down Libyan international communications.
Of course, without El Fadli’s critical input we could move no further with the investigation, and Randy called for a hiatus to further deliberations.
In early March, Gaddafi began airing long nightly rambling tirades on his government TV network. During one of these, he made an ominous reference to how NATO forces were using Libyan climate data to plan their assault on the country. My heart sank when I heard this. I immediately thought that our colleague, El Fadli--as director of the LNMC--must have been implicated by Gaddafi as providing weather information to the "enemy".
I must say, at that point, I--and the rest of the committee--thought El Fadli was a dead man.
We didn’t hear again from El Fadli until August 2011 when the revolutionary forces closed in on Tripoli. One of our committee members, Dr. Manola Brunet (WMO chair of the Open Programme Area Group on Monitoring and Analysis of Climate Variability and Change), who knew El Fadli personally, had up until then been unable to contact him by phone or email. Then on August 13, 2011, we received our first email from El Fadli.
El Fadli here relates the situation he faced during those long months when we lost communication with him:
“During that critical time all communication systems in Libya were shut down by the regime so it was impossible to communicate with anyone, even inside the country. Mobile telephone communications were restricted and even local calls were controlled and monitored. What was amazing however, believe or not, was that my office satellite Internet connection was still up and running. But using such posed serious dangers, if anyone discovered me I would probably lose my life. Hence, I never used that connection. The first 3 months (February-May) I was able to reach my office (my home being about 5 km east of El Azizia and 40 km to my office in Tripoli) but then in May we suffered from short fuel supplies, electricity, and even cooking gas. You can imagine how difficult our lives became! The other serious story involved the security situation. When I borrowed a car belonging to the local United Nations office (since I had no fuel for my own car) I was driving to morning prayers (04:00 am) with my sons and suddenly we came under gunfire from the back and rear of the vehicle. The vehicle was struck as I drove at a crazy speed with our heads ducked low. Our life was spared by the grace of God. This happened in late July.”
Then, as we all watched through the technology of television and Internet, by September 2011, the dictator Gaddafi was gone … and El Fadli was back!
With the investigation back on track, committee members made further progress in October and November. Dr. David Parker of the U.K. Met Office did a reanalysis of surface conditions across the Libyan region for September 1922. The results displayed a significant departure (up to 6 sigmas) from what the temperature observed at Azizia was to what the reanalysis plotted for the area. This was a key discovery, using technology that had never been available in past investigations of the Libyan record.
A chart produced by committee member David Parker following his reanalysis of the Azizia record. One could clearly see how the maximum temperature of 58°C in September 1922 was well beyond the top percentile that might have been expected.
Also, Philip Eden of the Royal Meteorological Society and others uncovered information concerning the unreliability of the Bellani-Six type of thermometer that had apparently been used at Azizia in September 1922. Of particular interest was how the slide within the thermometer casing was of a length equivalent to 7°C. It would be easy for an inexperienced observer to mistakenly read the top of the slide for the daily maximum temperature rather than correctly reading the bottom of such slide, a point that El Fadli made in a message to me early on in the investigation.
A 1933 instrument catalog image of the Bellani-Six style thermometer. Image supplied by Paolo Brenni, President of the Scientific Instrument Commission, and courtesy of Library of the Observatorio Astronomico Di Palermo, Gisuseppe S. Vaiana.
With all the pieces of the puzzle now falling into place, a vote was taken in January 2012 resulting in a unanimous decision by the WMO committee members to disallow the Azizia record.
As Tom Peterson put it, “The eventual answer seemed so clear and obvious that we evidently must have done a far more in depth investigation than any earlier one.”
Conclusions
In the end, and based on the unanimous decision by the 13 committee members, Randy Cerveny and Jose Luis Stella of Argentina, (the WMO’s co-Rapporteurs of climate and weather extremes), rejected the 58ºC temperature extreme measured at El Azizia in 1922.
The WMO committee added the following comment to my blog as it appeared on the BAMS web site front page: ”An important aspect of this long investigation was that it just isn’t climatologists and meteorologists changing their minds. It goes beyond that. This investigation demonstrates that, because of continued improvements in meteorology and climatology, researchers can now reanalyze past weather records in much more detail and with greater precision than ever before. The end result is an even better set of data for analysis of important global and regional questions involving climate change. Additionally, it shows the effectiveness of truly global cooperation and analysis. Consequently, the WMO assessment is that the official highest recorded surface temperature of 56.7°C (134°F) was measured on 10 July 1913 at Greenland Ranch (Death Valley) CA USA.
I agree with this comment as well, although I still have my suspicions about the Greenland Ranch figure of 1913. Time for another investigation!
REFERENCE NOTE:For the official WMO assessment report and all the references associated therewith please see the September 2012 issue of BAMS magazine (Bulletin of the American Meteorological Society).
KUDOS: Maximiliano Herrera for initially bringing the Azizia issue to my attention, Piotr Djakow for producing the first graphic that made the Azizia error so clear, Jim Pettit for helping me along the way with graphic analysis and encouraging advise, and Randy Cerveny for picking the ball up and championing the investigation. Also, of course, a big thanks to El Fadli without whom this investigation would never have happened, all the other WMO Committee members for their diligent work. In addition I want to thank Weather Underground, especially Jeff Masters and Shaun Tanner, for providing me the platform from which I can blow my horn!
Links:
Don't miss the 25-minute wunderground video,Dead Heat, a detective story on how the Al Azizia record was overturned.
Christopher C. Burt
Weather Historian
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Updated: 17:55 GMT le 13 septembre 2012
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August 2012 Global Weather Extremes Summary
August 2012 Global Weather Extremes Summary
There is never a dull month when it comes to extreme weather and August 2012 was no exception. The month began with a massive flood in Manila, Philippines and an intense heat wave in the south-central U.S. Two very sharp heat waves affected much of Europe during the 2nd and 3rd weeks of the month smashing records from Spain to Poland and the Ukraine. Typhoons walloped coastal sections of China and Hurricane Isaac thrashed the U.S. Gulf Coast.
Below is a summary some of the month’s highlights.
NORTH AMERICA
An intense heat wave in the southern plains exacerbated the on-going drought conditions and the temperature at Oklahoma City reached 113°F (45°C), the warmest temperature ever measured in the city. By mid-August, however, a very cool air mass invaded most of the central portion of the country and temperatures even fell to freezing at a few locations in Minnesota and Wisconsin. In spite, of the mid-month cool down some sites have ended up enduring their hottest summer on record. Denver, Colorado has averaged 76.3° for its climatological summer (June-August) beating its former warmest summer of 1954 by a full 2°F (old record was 74.3°F). The warmest temperature in the world during August was 126°F (52.2°C) measured at Death Valley, California on August 9th.
Sub-tropical moisture brought intense rainfall to portions of the desert southwest on August 22nd. Las Vegas, Nevada recorded its 2nd wettest calendar day on record with 1.68” that caused flash flooding resulting in one drowning death in the city. (Mesquite, near Las Vegas, picked up 2.04”, its greatest 24-hour rainfall on record/since 1992). Some other desert locations measured over 4” of rain in just a few hours (4.03” at Mid Hills RAWS in San Bernardino County, California—about what this site might expect in an entire year). One site in Nevada’s Mohave County, Wikieup, received 1.42” of rain in just 30 minutes. Ironically, Seattle, Washington (normally perceived as wetter than Las Vegas!) received no measureable precipitation during the entire month of August, and of this writing, is approaching its record of 51 rain-free days set in 1951 (last rainfall this summer was on July 22nd).
Hurricane Isaac made landfall in Louisiana on August 27 as a CAT 1 storm although its large size, strong storm surge (as high as 13’,) and central pressure (as low as 966mb) was more indicative of a strong CAT 2 cyclone. Seven storm-related deaths were reported mostly associated with the 15-20” rainfalls that fell along the path of the slow moving storm. The damage (at least US$2 billion) caused by Isaac is still under review as of this writing.
Flooding reminiscent of Hurricane Katrina ravaged some New Orleans-area neighborhoods like Plaquemines Parish southeast of the city. Ironically, Isaac struck virtually on the 7th anniversary of Katrina. Photo by Carolyn Cole, Los Angeles Times).
Hurricane Ernesto struck the western coast of Mexico on August 9th resulting in the deaths of two.
The Arctic measured its lowest sea ice extent since observations began in 1975. By August 26th the ice extent had shrunk to 1.58 million square miles, about 277,000 square miles less than the previous record low set in September 2007.
The coldest temperature measured in the northern hemisphere during August was -36.1°C (-33.0°F) at Summit AWS, Greenland on August 30th.
SOUTH AMERICA and CENTRAL AMERICA
Tartagal, Argentina recorded a temperature of 38.8°C (101.8°F) on August 22nd a record for the month at that location.
EUROPE
Europe experienced its most intense heat wave since the famous heat wave of 2003 and, in fact, many locations measured even higher temperatures than that occasion. All-time national heat records were set in the Czech Republic (40.4°C/104.7°F at Dobrichovice on August 20th), Moldova (42.4°C/108.3°F at Falesti on August 7th), and Montenegro (44.8°C/112.6°F at Danilovgrad on August 8th). In the Pyrenees along the French and Spanish border virtually every site recorded its warmest temperature on record. For more details on the European heat waves of August see my previous blog on the subject. Wild fires have raged out of control in both Spain and Greece with several fatalities reported from the Spanish resort area around Marbella.
August weather extremes for the United Kingdom are not yet available.
An intense wild fire threatens a beach resort on the island of Chios in the Greek archipelago on August 18th. Photo from EPA archives.
AFRICA
Monsoonal rains resulted in deadly floods in Nigeria and Cameroon during the month. At least 14 flood-related deaths were reported in Cameroon’s north region and at least 15 in Nigeria’s central provinces.
On August 25th and 26th the temperature peaked at 42.5°C (108.5°F) at Mtunzini, South Africa. This was not only a winter record for South Africa but also close to the warmest temperature ever measured in the southern hemisphere during the winter months (44°C has been recorded at Villamontes, Bolivia during previous Augusts). Needless to say, this was the warmest temperature measured in the southern hemisphere during this past August.
ASIA
Although this years summer monsoons have failed to materialize in much of South Asia, heavy rains in the mountains of northern Pakistan on August 20-23 resulted in flash floods that drowned at least 26.
It was a very active month typhoon-wise in the Western Pacific. Notable typhoons struck Macao and Hong Kong including Typhoon Kai-tak that caused winds to gust to 87 mph at Hong Kong’s International Airport on August 23 and 27 lives were lost in China’s Guangdong and Guangxi Provinces. It was the strongest typhoon to hit Hong Kong since 1999. Typhoon Bolaven was the strongest typhoon to hit the Korean Peninsula since 2002 when it roared ashore on August 28th. At least 18 deaths (mostly fisherman) were reported as a result of the storm with at least a further 48 fatalities reported just recently from North Korea.
The biggest weather story of the month in Asia, however, was the tremendous flood that engulfed Manila in the Philippines between July 31-August 8th. Up to 1000 mm (40”) of rain was reported to have fallen in Quezon City during the week of rains and there were some 60 fatalities reported. For details about the flood see Angela Fritz’s August blog on the subject.
Manila’s streets turned into lakes during the phenomenal flood that affected the city the first week of August. Photo by Jof Cubol.
AUSTRALIA
Australia had a warmer and drier August than normal, reversing (temperature-wise) the cold weather endured over much of the country the previous July. It was Western Australia’s driest August since 1995 and 2nd warmest August on record.
A very warm month virtually nation-wide for Australia this past August (top map). Precipitation was also below normal in most of the country, especially in portions of Western Australia where it was the driest August on record (bottom map). Maps courtesy of the Australian Bureau of Meteorology.
The warmest temperature recorded in Australia during this past August was 38.5°C (101.3°F) at Fitzroy Crossing, Western Australia on August 27th and the coldest -4.9°C (23.2°F) at Thredbo Top Station, New South Wales on August 6th. The greatest calendar day precipitation was 73.0mm (2.87”) at Mount Sabine, Victoria on August 18th.
NEW ZEALAND/SOUTH PACIFIC
It was generally a mild and wet August in New Zealand although there was a sharp contrast in precipitation totals on the South Island where anomalies ran the gamut from 10% to 400% of normal!
The extreme anomaly between very dry and very wet weather that affected the South Island in August can be seen in this map above. Map courtesy of NIWA.
The highest temperature recorded was 22.7°C (72.9°F) at Christchurch, South Island on August 26th and the lowest -5.3°C (22.5°F) at Ranfurly on August 23rd. The greatest calendar day rainfall was 198 mm (7.80”) at Akaroa on August 25th.
ANTARCTICA
The coldest temperature in the southern hemisphere and the world during August was -80.0°C (-112.0°F) recorded at Vostok on August 7th.
KUDOS Thanks to Maximiliano Herrera for global temperature extremes data, Stephen Burt for the U.K. extremes, and Jeremy Budd and NIWA for New Zealand weather extremes.
Christopher C. Burt
Weather Historian
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Updated: 20:53 GMT le 04 septembre 2012
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