The IRI has prepared this experimental Climate Outlook for Europe for October 2001 - March 2002. Of relevance in the preparation of this outlook is the prediction of near-average to slightly warmer than average conditions in the eastern equatorial Pacific for the next 6 to 9 months. Currently the sea surface temperatures (SSTs) across much of the eastern and central equatorial are near their long-term average (SSTs), although slightly lower than average SSTs have developed along the immediate western coast of South America and warmer than average SSTs persist in the extreme western part of the basin. Near neutral equatorial Pacific SST conditions are in effect for the first season of the forecast, October-December 2001, November-January 2002, December-February 2002, while during the second season, January-March 2002, they are expected to be slightly above average. The warmer than average SSTs that continue to dominate much of the Indian Ocean are expected to decrease slowly through the forecast period. The area of above-average temperature in the tropical south Atlantic Ocean is expected to persist through at least the first half of the forecast period.

METHODS -

This Outlook was prepared using the following procedures and information:

A) Coupled ocean-atmosphere model predictions of tropical Pacific SST covering the forecast period. Particularly heavy weighting has been given to predictions from the coupled model operated by the NOAA National Centers for Environmental Prediction, Climate Modeling Branch. This model suggests a continuation of near-average conditions during the first forecast season. The forecast for near-neutral conditions is consistent with some, but not all, numerical and statistical forecasts of central and eastern Pacific SSTs.

B) Forecasts of the tropical Indian ocean using a statistical model developed by the IRI.

C) Global atmospheric general circulation model (GCM) predictions of the atmospheric response to the present and predicted sea-surface temperature patterns.

D) Other sources of information include NASA's Seasonal to Interannual Prediction Project (GSFC-NASA).

The procedures, models, and data used to derive this Climate Outlook may be somewhat different from those used by the national meteorological services in the region. Thus, this product may differ from the official forecasts issued in those areas. The Climate Outlook for October 2001 - March 2002 is dependent on the accuracy of the SST predictions. For the tropical Pacific, these predictions can be expected to provide useful information, but there is some uncertainty concerning the evolution of SSTs. Spread in global SST predictions is a source of uncertainty in the Outlook provided here. Note that even if perfectly accurate SST forecasts were possible, there would still be uncertainty in the climate forecast due to chaotic internal variability of the atmosphere. These uncertainties are reflected in the probabilities given in the forecast.

It is stressed that the current status of seasonal-to-interannual climate forecasting allows prediction of spatial and temporal averages, and does not fully account for all factors that influence regional and national climate variability. This Outlook is relevant only to seasonal time scales and relatively large areas; local variations should be expected, and variations within the 3-month season should also be expected. For further information concerning this and other guidance products, users are strongly advised to contact their National Meteorological Services.

OUTLOOK -

This Outlook covers four seasons: October-December 2001, November-January 2002, December-February 2002 and January-March 2002. Maps are given showing tercile probabilities of precipitation and temperature. The maps for precipitation indicate the probabilities that the seasonal precipitation will fall into the wettest third of the years (top number), the middle third of the years (middle number), or the driest third of the years (bottom number). The color shading indicates the probability of the most dominant tercile -- that is, the tercile having the highest forecast probability. The color bar alongside the map defines these dominant tercile probability levels. The upper side of the color bar shows the colors used for increasingly strong probabilities when the dominant tercile is the above-normal tercile, while the lower side shows likewise for the below-normal tercile. The gray color indicates an enhanced probability for the near-normal tercile (nearly always limited to 40%). As before, numbers and their associated histograms show the probabilities of the three terciles. In areas with lots of spatial detail, there may not be sufficient room on the map, to allow histograms for each region. In those cases, some idea of the probabilities may be gained from the color alone. A qualitative outlook of climatology ("C") indicates that there is no basis for favoring any particular category. Areas that are marked by "D" represent regions experiencing their dry season (less than 15% of annual precipitation) and for which less than 5cm of precipitation typically occurs over the season. Otherwise, for example, in the case of October-December 2001 (Map A), there is a 40% probability that the precipitation will be in the wettest third of the years, a 35% chance it will be in the near-normal third of the years, and a 25% chance that the precipitation will be in the driest third of the years over parts of the United Kingdom.

Maps of temperature show expected probabilities that the seasonal temperatures will fall into the warmest third of the years, the middle third of the years, or the coldest third of the years (Map A) . The numbers for each region on the temperature maps indicate the probabilities of temperatures to fall in each of the three categories, above-, near-, and below-normal.

An additional precipitation map is provided for the first season indicating probabilities for extreme precipitation anomalies. Extremes are defined as anomalies that fall within the top and bottom 15th percentile of the observed records. A priori, there is a 15% probability of being within the extremely wet category, and a 15% probability of being within the extremely dry category, leaving a 70% probability that the precipitation will not be extreme. The maps indicate areas of increased risk of extreme precipitation totals. Three levels of increased risk are defined: slightly enhanced risk, enhanced risk, and greatly enhanced risk. For slightly enhanced risk, there is a 25-40% probability that precipitation will be within the indicated extreme, i.e. wet or dry. This represents an approximate doubling of the climatological risk. For enhanced risk, there is a 40-50% probability that precipitation will be within the indicated extreme. This represents an approximate tripling of the climatological risk. For greatly enhanced risk, the probability that precipitation will be within the indicated extreme exceeds 50%, i.e. the indicated extreme is the most likely outcome. A similar map is provided in the first season indicating probabilities of extreme temperature anomalies.

Boundaries between sub-regions should be considered as transition zones, and their location considered to be only qualitatively correct.

October-November-December Year:

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for the northern parts of Sweden, Norway and Finland.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for eastern Iceland.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for Scotland, Ireland, Northern Ireland, and Wales.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for much of Denmark,southern Norway and southwestern Sweden.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for portions of Romania, Yugoslavia and Bulgaria.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for much of Portugal and northwestern Spain.

An enhanced probability for below normal precipitation (45%-30%-25%) is forecast for northern Iran, and parts of Iraq and Saudi Arabia, surrounded by more weakly enhanced probabilities for below normal precipitation in additional portions of Iran, Iraq and Saudi Arabia, southwest Russia and extreme western Turkey.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for Franz Josef Land in the Arctic Ocean.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for extreme northern Norway.

Slightly enhanced probabilities for above normal temperature (25%-35%-40%) are forecast for part of eastern Greenland, and Iceland.

A greatly enhanced probability for above normal temperature (15%-30%-55%) are forecast for most of the United Kingdom, surrounded by more weakly enhanced probabilities for above normal temperature in most of the remainder of western Europe from southern Scandenavia southward.

A greatly enhanced probability for above normal temperature (15%-30%-55%) are forecast for central Italy and southern Croatia, surrounded by more weakly enhanced probabilities for above normal temperature in most of the remainder of eastern Europe, including the Middle East and much of western Russia northward nearly to the Baltic Sea.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for part of Poland.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Portugal and northwestern Spain.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for a small part of southwest Russia, in the vicinity of Georgia and Azerbaijan.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Sardinia.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Crete and the easternf Meditteranean Sea.

Slightly enhanced probabilities for below normal temperature (40%-30%-30%) are forecast for small portions of northern Norway and Sweden.

November-December-January Year:

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for northeastern Greenland.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for southern parts of Sweden and Norway.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for Scotland and Shetland Island.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for Iceland.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for various portions of France, Germany, Switzerland, Austria, Czech Republic, Slovenia, Croatia, Hungary, Spain, Bosnia-Herzg and Yugoslavia.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for central Turkey.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for southeastern Greenland.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for Shetland Island, Ireland, Northern Ireland, and a small part of northern England.

An enhanced probability for above normal temperature (25%-30%-45%) is forecast for northeastern France and southwestern Germany, surrounded by more weakly enhanced probabilities for above normal temperature in much of the remainder of central western Europe south of Scandenavia.

Slightly enhanced probabilities for above normal temperature (25%-35%-40%) are forecast for much of the southern tier of Europe, surrounding more strongly enhanced probabilities for above normal temperature in northern Africa.

An enhanced probability for above normal temperature (20%-35%-45%) is forecast for the Azores.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Spitsbergen and northern parts of Norway, Sweden and Finland.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for northeast Turkey, and extreme southwestern Russia.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Portugal and adjacent portions of Spain.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Sicily.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for central and eastern Turkey, and small portions of adjacent countries.

Slightly enhanced probabilities for below normal temperature (40%-30%-30%) are forecast for northwestern Russia along the Barents Sea.

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for western Russia (Latvia, Lithuania, Belarus).

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for a tiny part of Iran and southwestern Russia, Kazakhstan, Uzbekistan, Turkmenistan).

December-January-February Year:

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for part of western Russia and extreme western Finland.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for a part of central Norway.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for southern England, a part of southeast Sweden, northern and western Poland, northern Czech Republic, central and northern Germany, southern Denmark, most of Belgium and the Netherlands.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for most of Romania, much of Bulgaria and a small part of western Russia.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for much of Portugal and northwestern Spain.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for the eastern half of Turkey and a small part of southwestern Russia.

Slightly enhanced probabilities for above normal temperature (25%-35%-40%) are forecast for northern Norway, northern Sweden and northern Finland.

Slightly enhanced probabilities for above normal temperature (25%-35%-40%) are forecast for Iceland.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for the southern tip of Greenland.

An enhanced probability for above normal temperature (25%-30%-45%) is forecast for western Poland, northern Czech Republic and eastern Germany, surrounded by more weakly enhanced probabilities for above normal temperature in most of the United Kingdom, northern France, most of Germany and portions of additional countries in central Europe.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for a small portion of southwestern Russia.

An enhanced probability for above normal temperature (20%-35%-45%) is forecast for the Azores.

An enhanced probability for above normal and near normal temperature (20%-40%-40%) is forecast for part of southern Turkey, most of Syria, and other countries in the Middle East.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for southern Portugal.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for part of northern Spain.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for much of the western Mediterranean region.

Slightly enhanced probabilities for below normal temperature (40%-30%-30%) are forecast for northwestern Russia.

January-February-March  Year:

An enhanced probability for above normal precipitation (25%-30%-45%) is forecast for a large portion of central Scandenavia and northwestern Russia, surrounded by more weakly enhanced probabilities for above normal precipitation in most of the remainder of Scandenavia and much of the northern two-thirds of Europe except for the United Kingdom.

An enhanced probability for above normal precipitation (25%-30%-45%) is forecast for the Netherlands, Belgium-Luxemburg and western Germany, surrounded by more weakly enhanced probabilities for above normal precipitation in parts of France, most of Germany, southern Denmark and small portions of surrounding countries.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for southo-central Greenland.

An enhanced probability for below normal precipitation (45%-30%-25%) is forecast for Bulgaria and parts of immediately adjacent countries, surrounded by more weakly enhanced probabilities for below normal precipitation in additional parts of Turkey, Romainia, Macedonia and Greece.

An enhanced probability for above normal temperature (25%-30%-45%) is forecast for parts of western Russia, eastern Finland, and much of Poland, surrounded by more weakly enhanced probabilities for above normal temperature in a substantial portion of the remainder of non-southern part of eastern Europe.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for part of northern Iran and much of Iraq, extending southward into Saudi Arabia and Africa.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for the northern parts of Sweden, Norway and Finland.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Iceland.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for a vast portion of western Europe, including southern and much of central Scandenavia.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for northern Turkey, southwestern Russia.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for the Azores.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for part of Italy, including part of Sardinia.

Slightly enhanced probabilities for near normal temperature (35%-40%-25%) are forecast for the part of the Mediterranean between Crete and Cyprus.

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for a small part of northwestern Russia, and Novaya Zemlya.

OBSERVED CLIMATOLOGY DATA Oct-Nov-Dec, Nov-Dec-Jan, Dec-Jan-Feb and Jan-Feb-Mar

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