from Gogerddan; the Cambrian News, Aberystwythfor apresscuttingdescribingtheflooding; Mrs Sue Ballard of the Meteorological Office for providing the mesoscale model charts; and Mr Michael Bader, Dr John Brownscombe, and Mr Martin Young of the Meteorological Office for their helpful comments and suggestions.

REFERENCES Monk,G. A.,Rowley,L.H.G.,Smith,F. andBader,M. J. (1990)Climatologiesoftopographically

related convection over the British Isles. In: EUMETSAT, Proc. 8rh Mereosar Scientific Users' Meeting, Norrkoping, Augur 1990, Swedish Met. and Hydrol. Inst., pp. 121-125

Pike, W. S. (1990) Radar study of the snowfall in south-west Cornwall on 12 January 1987. Mereorol. Mag. , 119, pp. 97-102

REVIEW OF WINTER 1991/92 IN THE NORTHERN HEMISPHERE IMPORTANT CLIMATOLOGICAL EVENTS

The Intergovernmental Panel on Climate Change met in China in December. At this conference the estimate of probable global warming was revised downwards: the best estimate is now a l d e g C rise by the year 2030. The continuing depletion of ozone over the globe accounts for part of this reduction (ozone acts as a greenhouse gas).

Although Central England Temperature (CET) was about 1 degC lower in 1991 than in 1990, over the globe the two years had very similar mean temperatures and 1991 is the second warmest (after 1990) in the global mean temperature series which goes back to the mid-nineteenth century. Seven of the eight warmest years in this series have occurred since 1980 and global snow cover has decreased noticeably in the second half of the 1980s.

Many parts of East Anglia and south-east England have had three consecutive years of very low rainfall. In some parts the deficit amounts to about nine months of normal rainfall. As a result, many of the normally vigorous trees in southern England appear to be suffering. Beech trees are the most affected but oaks and Scots pines are also in trouble.

There is a weak El Nino in the tropical Pacific where sea surface temperatures are between 1 and 2 degC above normal. In the North Atlantic Ocean temperatures remain below normal north of about 58" N but south of 50" N anomalies are slightly positive.

The Meteorological Office, in association with a commercial company, intend t o launch a weather channel on cable T V later this year.

DECEMBER

The seasonal increase in hemispheric flow at 500mbar was well marked and resulted in a three-wave pattern with troughs at 6VW, W E and near 150"E in the eastern North Pacific. There was a very strong upper ridge over the British Isles with a monthly mean anomaly of more than 15dam over the whole of the UK. The circumpolar vortex was close to the pole but with a trough extending southwards to Baffin Island. The jet stream was very strong in the North Pacific and in the western North Atlantic but was displaced well north in the eastern North Atlantic.

The corresponding monthly mean surface chart showed the Azores high displaced to northern France with a monthly anomaly of over 12mbar over Britain (a record for December). The Iceland low was split into two but the Aleutian low was deeper than usual.

There was a notable cold plunge over Europe into the central and eastern Mediterranean early in the month. When this cold air reached the relatively warm Mediterranean, some notable falls of rain occurred, 115 mm in 36 hours in Malta and 116mm in 48 hours in southern Sicily. There were also torrential falls in Israel, Jordan

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and Turkey, and Cyprus had its wettest December this century. However, Britain and most of Europe had a relatively dry month.

Monthly mean temperatures were below average over Europe south of about 50"N with anomalies as large as -4 to -5 degC over Greece but it was milder than usual over Scandinavia (+6 degC) and northern Asia. Most of North America was also milder than normal with anomalies up to +7 degC in places. However, there was a relatively cold belt from Alaska across north Canada to Labrador.

The persistent anticyclonic weather resulted in nitrogen dioxide (NO2) pollution reaching 423 parts per billion (ppb) of air in London on the 23rd (air quality is regarded as very poor above 300ppb of NOz).

Winds gusted to over 80kn in Wales and some western districts of England on the 23rd.

Central England Temperature England & Wales Rainfall (prouisional)

4.7"C (0.0 degC) 40.7 mm (45 per cent)

JANUARY

There is a remarkable similarity between the 500mbar monthly mean patterns of December and January. The three-wave pattern persisted with the main troughs and ridges at 50"N in much the same longitudes. The largest positive anomaly in the hemisphere again covered Britain but this month the anomaly was even bigger, exceeding 21 dam over much of northern Britain.

The position of the circumpolar vortex and the strength and position of the jet streams were also, as might be expected, similar to those in December. On the monthly mean surface chart also, the Aleutian low was again deeper then usual and the Iceland low split. These facts were mirrored in the very persistent anticyclonicity in the region of the British Isles over the two months.

It was a mild January over most of Asia north of 30"N, eastern Europe and North America except for northern Canada and Newfoundland. It was a colder than usual month over Spain, north Africa, Turkey (anomaly -5 degC) and the Middle East. It was a dry month over most of Europe and North America between 40 and 60"N but wetter than usual in northern Canada and central Asia.

There were severe snowstorms in Jordan, Israel and the Lebanon with 400 mm of snow in Jerusalem on one occasion. There were also blizzards in southern France h d inland from the Costa Brava in Spain. Avalanches killed several hundred people in south-east Turkey.

Central England Temperature England & Wales Rainfall (prourkional)

3.6"C (+0.1 degC) 45.5 mm (53 per cent)

FEBRUARY

On the 500mbar monthly mean chart heights were higher than usual at 50"N almost all round the hemisphere. The circumpolar vortex was exceptionally deep and centred over the Davis Strait. The jet stream was very strong between Iceland and Scotland but that in the North Pacific was rather weak. On the monthly mean surface chart the Iceland low was 16mbar deeper than normal while the Azores high was displaced to France where the anomaly was + 10 mbar.

It was a mild February over most of Europe, Asia and North America except for, north-east Canada. However, cold weather persisted over the eastern Mediterranean and the Middle East. There was heavy snow in southern Turkey and in Athens on the 23rd. Precipitation was less than usual over western Europe and much of North America.

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Central England Temperature England & Wales Rainfall (prouisional)

5 4 ° C (+1.7 degC) 41.5 mm (64 per cent)

WINTER AS A WHOLE

It was a milder than usual winter over most of North America (except north-east Canada), much of central and northern Asia and central and northern Europe. However, south-east Europe and the Middle East had a very severe winter with unusually heavy precipitation and considerable snowfall.

Central England Temperature England & Wales Rainfall (prouisional) Over England and Wales it was the fifth driest winter since records began and

R. A. S. RATCLIFFE

4.6”C (+0.7 degC) 127.7 mm (54 per cent)

only 1933134 and 1963164 have been drier this century.

NEWS PAST PRESIDENT E L E n E D AS FOREIGN ASSOCIATE

Dr Keith Browning, past President of the Royal Meteorological Society and currently at Reading University on sabbatical leave from the Meteorological Office, has been elected a Foreign Associate of the National Academy of Engineering of the United States. The award was made for “Fundamental contributions to the detection and understanding of storms, and the development of operational storm-detection and warning systems”.

ROYAL METEOROLOGICAL SOCIETY F.H.W. GREEN PRIZE - 1992 ARRANGEMENTS

Frank Green, who died in 1983, devoted a major part of his 60-year research career to the advancement of applied climatolo y His wide range of interests spanned hydrological, agricultural, synoptic and local climatokgy. In all these areas he not only made significant contributions, but he also generated interest and commitment in others.

As a tribute to his work, the Association of British Climatologists awards an annual F.H.W. Green Prize. Heads of departments in universities, polytechnics and colleges in the UK are invited to submit one undergraduate dissertation in the field of climatology of sufficient merit to warrant consideration for this prize.

Further details and an application form can be obtained from: Dr J. McClatchey, Department of Geography, Portsmouth Polytechnic, Lion Terrace, Portsmouth, Po1 3HE.

The hnnier side of weather Mr C. G. Holmes sent in the following item which was headed “State-wide fan belt to

“Prof. Holbrook Landers of Florida University has thought of a remarkable scheme to save the State’s fruit and vegetable crops from severe winter weather.

He told a national conference on agricultural meteorology yesterday that his plan involves a double row of electric fans across the entire ‘neck’ of Florida. This would prevent freezing ‘air from the north-north west causing frost damage.

Installation of these fans with 121ft blades on 62ft towers would cost up to f10 million. But together with operation costs this would be only a fraction of the f52 million lost by the citrus industry in the winter of 1957-58.”

beat frost”, and was taken from the Daily Telegraph for 1 April 1963:

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