The IRI has prepared this experimental Climate Outlook for Asia for August 2001 - January 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, August-September-October 2001, September-October-November 2001, October-November-December 2001, while during the second season, November-December 2001-January 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 August 2001 - January 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.

This Outlook covers four seasons: August-September-October 2001, September-October-November 2001, October-November-December 2001 and November-December 2001-January 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 the Philippines in August-September-October 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.

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.

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

August-September-October 2001:

The following regions of enhanced probabilities of precipitation anomalies are indicated:

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for a portion of eastern China, and Korea.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for central Nepal and a sizeable portion of India.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for southeastern Afghanistan and a small portion of adjacent Pakistan.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for the outer (western) Aleutian Islands of Alaska.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40% and 25%-35%-40%) are forecast for the Philippines, extending southward into Halmahera Island and surroundings.

An enhanced probability for below normal precipitation (45%-35%-20%) is forecast for southeastern Sumatra and most of Java. Weaker probabilities for below normal precipitation (40%-35%-25%) surround this region, including much of the remainder of Sumatra, southern Malaysia, much of Borneo, and easternmost Java.

Slightly enhanced probabilities for near normal precipitation (30%-40%-30% and 25%-40%-35%) are forecast for Irian Jaya of New Guinea, western Papua New Guinea, and Tanimbar and Ceram Islands.

Slightly enhanced probabilities for near normal precipitation (35%-40%-25%) are forecast for a small part of southeastern Borneo, part of the Celebes, and parts of the Lesser Sundra Islands, and part of Timor.

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for part of eastern Papua New Guinea.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40% and 25%-35%-40%) are forecast for extreme eastern Papua New Guinea, and the small islands east of it, such as New Britain.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for Wake Island of the United States.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for the western portion of Kiribati.

The following regions of enhanced probabilities of temperature anomalies are indicated:

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

Slightly enhanced probabilities for below normal and near normal temperature (40%-40%-20%) are forecast for Kamchatka, Russia, the Kuril Islands, and the western Aleutian Islands of Alaska.

A greatly enhanced probability for above normal temperature (20%-30%-50% and 15%-35%-50%) is forecast for part of eastern China and most of North Korea, as well as separate but associated regions in the Ryukyu Islands and the Izu Islands near Japan (15%-30%-55%), and thirdly in the Philippines and Brunei and the northern part of the eastern portion of Malaysia (15%-30%-55%), and fourthly in Irian Jaya of New Guinea (15%-30%-55%). Weaker probabilities for above normal temperature (20%-35%-45%, 10%-45%-45%, 25%-35%-40%, and 20%-40%-40%) surround and connect these four regions, including additional large portions of China, Russia, Myanmar, Thailand, Laos, North Vietnam, central and eastern Indonesia, and many of the islands in the western tropical Pacific.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Sumatra, Java, southern Malaysia, most of Borneo, Malaysia, most of the Celebes, Buru and Ceram Islands of the Moluccas, and western Timor.

September-October-November 2001:

The following regions of enhanced probabilities of precipitation anomalies are indicated:

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for northern Russia, on the Arctic Ocean.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for northern China and southern Mongolia.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for northeast China, a small part of southeast Russia, and North Korea.

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

Slightly enhanced probabilities for near normal precipitation (35%-40%-25%) are forecast for part of eastern and east-central China.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for southern China and extreme eastern India.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for mainly central and northwestern India, and extreme east-central Pakistan.

An enhanced probability for above normal precipitation (25%-30%-45%) is forecast for northeastern Afghanistan. Weaker probabilities for above normal precipitation (30%-30%-40%) surround this region, including most of the remainder of Afghanistan, northern and northwestern Pakistan, and a small portion of southern Russia.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for part of south-central and southern China.

An enhanced probability for above normal precipitation (25%-30%-45%) is forecast for Guam, United States, and Yap Island of Micronesia. Weaker probabilities for above normal precipitation (30%-30%-40%) surround this region, including some more of Micronesia and Palau.

A greatly enhanced probability for above normal precipitation (20%-30%-50%) is forecast for Wake Island, United States.

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for western Kiribati.

An enhanced probability for above normal precipitation (15%-40%-45%) is forecast for the southern Philippines, extreme northeastern Celebes, and western Halmahera Island, as well as a separate but associated region just north of Timor (20%-35%-45%). Weaker probabilities for above normal precipitation (25%-35%-40% and 30%-30%-40%) surround and connect these two regions, including much of the remainder of the Philippines, an addition portion of the Celebes, the Moluccas Islands, and Timor.

Slightly enhanced probabilities for near normal precipitation (30%-40%-30% and 25%-40%-35%) are forecast for Tanimbar Island, the Northern Territory and Queensland of Australia (see Australia map), southern Irian Jaya of New Guinea, and Papua New Guinea.

A greatly enhanced probability for below normal precipitation (45%-35%-20%) is forecast for the southern coast of Sumatra and southwest coast of Java. Weaker probabilities for bekiw normal precipitation (45%-30%-20% and 40%-35%-25%) surround this region, including central Sumatra, most of the remainder of Java, and central and southern Borneo.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for Irian Jaya of New Guinea.

The following regions of enhanced probabilities of temperature anomalies are indicated:

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

An enhanced probability for below normal temperature (45%-40%-15% and 45%-35%-20%) is forecast for part of Kamchatka and part of northeastern Russia to the north of Kamchatka. Weaker probabilities for below normal temperature (40%-40%-20%) surround these regions, including more of Kamchatka and more of northeastern Russia.

Slightly enhanced probabilities for near normal temperature (30%-40%-30% and 25%-40%-35%)) are forecast for southern Japan and part of South Korea.

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

Slightly enhanced probabilities for near normal temperature (30%-40%-30, 25%-40%-35, and 35%-40%-25%) are forecast for northeast China and southeast Russia.

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for southeast Russia.

Slightly enhanced probabilities for near normal temperature (30%-40%-30%) are forecast for a small part of southeastern China and Taiwan.

Slightly enhanced probabilities for near normal temperature (30%-40%-30% and 25%-40%-35%) are forecast for Burma, Bangladesh, and extreme eastern India.

Slightly enhanced probabilities for above normal temperature (30%-30%-40%) are forecast for northern Siberia of Russia.

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

Slightly enhanced probabilities for above normal temperature (30%-30%-40% and 25%-35%-40%) are forecast for much of China, part of northeastern India, Bhutan and northern Bangladesh.

October-November-December 2001:

The following regions of enhanced probabilities of precipitation anomalies are indicated:

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for northeast China, a small part of southeast Russia, North Korea, South Korea, and extreme southern Japan.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for Kamchatka, Russia, and the extreme western Aleutian Islands of Alaska.

An enhanced probability for below normal precipitation (45%-35%-20%) is forecast for a portion of southeastern China. Weaker probabilities for below normal precipitation (40%-35%-25% and 40%-30%-30%) surround this region, including additional parts of southern and southeastern China, extreme northern Taiwan, Hainan, and western North Vietnam.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for southern India and Sri Lanka.

An enhanced probability for above normal precipitation (20%-35%-45%) is forecast for the northern Philippines. Weaker probabilities for above normal precipitation (25%-35%-40% and 30%-30%-40%) surround this region, including extreme southern Taiwan, the southern Philippines, Brunei, most of eastern part of Malaysia, and northern Borneo.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for much of the Afghanistan-Pakistan border area.

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for north-central Pakistan, and a small portion of immediately adjacent Afghanistan.

The following regions of enhanced probabilities of temperature anomalies are indicated:

Slightly enhanced probabilities for above normal temperature (30 30 40 and 25 35 40) are forecast for extreme eastern Russia.

Slightly enhanced probabilities for above normal temperature (30 30 40) are forecast for eastern Russia, near northeast China and north of Japan.

Slightly enhanced probabilities for above normal temperature (25 35 40) are forecast for northwestern Siberia of Russia.

Slightly enhanced probabilities for above normal temperature (25 35 40) are forecast for much of northern and central China, and small adjacent portions of southern Mongolia.

Slightly enhanced probabilities for below normal temperature (40 30 30 and 40 40 20) are forecast for Kamchatka, part of eastern Russia to the north of Kamchatka, the Kuril Islands, Japan, and part of North Korea and South Korea.

November-December 2001-January 2002:

The following regions of enhanced probabilities of precipitation anomalies are indicated:

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for western Russia, west of the Kamchatka Peninsula.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for southern Siberia of Russia.

Slightly enhanced probabilities for above normal precipitation (25%-35%-40%) are forecast for southwestern Russia and northern Iran, extending westward into eastern Europe (see Europe map).

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for southern Japan, South Korea, part of North Korea, and a small part of southeastern Russia.

An enhanced probability for below normal precipitation (45%-35%-20%) is forecast for part of southern and southeastern China. Weaker probabilities for below normal precipitation (40%-35%-25%) surround this region, including Taiwan and additional portions of southeastern and southern China.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for southern India, western Sri Lanka and Maldive Island.

An enhanced probability for above normal precipitation (20%-35%-45%) is forecast for the central Philippines. Weaker probabilities for above normal precipitation (25%-35%-40% and 30%-30%-40%) surround this region, including the remainder of the Philippines, Brunei, much of the eastern part of Malaysia, extreme northern Borneo, the northern and eastern Celebes, eastern Timor, and some of the Moluccas Islands including Ceram and Buru.

An enhanced probability for above normal precipitation (20%-35%-45%) is forecast for the central Philippines. Weaker probabilities for above normal precipitation (25%-35%-40% and 30%-30%-40%) surround this region, including the remainder of the Philippines, Brunei, much of the eastern part of Malaysia, extreme northern Borneo, the northern and eastern Celebes, eastern Timor, and some of the Moluccas Islands including Ceram and Buru.

A greatly enhanced probability for above normal precipitation (20%-30%-50%) is forecast for certain tropical islands in the western Pacific, such as Palau and some of the Federated States of Micronesia. Weaker probabilities for above normal precipitation (15%-40%-45% and 25%-35%-40%) surround this region, including a wider range of tropical islands in the western Pacific.

The following regions of enhanced probabilities of temperature anomalies are indicated:

Slightly enhanced probabilities for above normal temperature (30 30 40) are forecast for E Russia, north of Japan.

Slightly enhanced probabilities for above normal temperature (30 30 40) are forecast for a small part of southwestern Russia, northwest China, and western Mongolia.

Slightly enhanced probabilities for below normal temperature (40 30 30) are forecast for northeastern Russia, north of Kamchatka.

Slightly enhanced probabilities for below normal temperature (40 30 30 and 40 35 25) are forecast for Japan, the Kuril Islands, and part of South Korea.

Slightly enhanced probabilities for below normal temperature (40 30 30 and 40 35 25) are forecast for the western Aleutian Islands of Alaska and Commander Island to the east of Kamchatka.

OBSERVED CLIMATOLOGY DATA for Aug-Sep-Oct, Sep-Oct-Nov, Oct-Nov-Dec and Nov-Dec-Jan

CLIMATOLOGICAL AVERAGE: Temperature Precipitation

TERCILE THRESHOLDS (33%-ile & 67%-ile): Temperature Precipitation

EXTREME THRESHOLDS (15%-ile & 85 %-ile): Temperature Precipitation

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