The IRI has prepared this experimental Climate Outlook for Asia 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.

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 most of India and Pakistan in October-December 2001 (Map A), there is a 25% 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 40% 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.

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:

An enhanced probability for above normal precipitation (25%-30%-45%) is forecast for parts of Russia, western Mongolia and extreme northwest China, surrounded by more weakly enhanced probabilities for above normal precipitation in additional portions of those three countries.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for extreme eastern Russia.

A greatly enhanced probability for above normal precipitation (15%-30%-55%) is forecast for the northern northern Philippines, surrounded by more weakly enhanced probabilities for above normal precipitation in the central Philippines.

A greatly enhanced probability for above normal precipitation (15%-30%-55%) is forecast for Yap Island of the Federated States of Micronesia, surrounded by more weakly enhanced probabilities for above normal precipitation in Guam, United States.

A greatly enhanced probability for below normal precipitation (50%-30%-20%) is forecast for southeast China, surrounded by more weakly enhanced probabilities for below normal precipitation in large additional portions of southern and eastern Asia, stretching from Afghanistan through India, southeastern Asia, and China to Japan.

A very greatly enhanced probability for above normal temperature (10%-25%-65%) is forecast for Myanmar, Thailand, Malaysia, and the Philippines, surrounded by more weakly enhanced probabilities for above normal temperature in most of the remainder of Asia.

A very greatly enhanced probability for above normal temperature (10%-25%-65%) is forecast for Yap Island of the Federated States of Micronesia.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%, 30%-40%-30%, and 35%-40%-25%) are forecast for various relatively small portions of Asia, including Kamchatka of Russia, parts of Japan, Vietnam, India and Afghanistan.

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for part of Kamchatka of Russia, and the outer Aleutian islands of Alaska, United States.

November-December-January Year:

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for extreme eastern Russia.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for scattered portions of Russia and Mongolia.

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for east-central China.

A greatly enhanced probability for above normal precipitation (15%-35%-50%) is forecast for part of the northern Philippines, surrounded by more weakly enhanced probabilities for above normal precipitation in additional portions of the Philippines, excluding the southern Philippines.

An enhanced probability for above normal precipitation (15%-40%-45%) is forecast for Yap Island of the Federated States of Micronesia, surrounded by more weakly enhanced probabilities for above normal precipitation in Guam, United States.

Slightly enhanced probabilities for near normal precipitation (30%-40%-30%) are forecast for northern India and small portions of immediately adjacent countries.

Slightly enhanced probabilities for near normal precipitation (30%-40%-30%) are forecast for southern Myanmar, and part of Thailand.

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for the southern Philippines and part of Malaysia.

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

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for eastern Russia, including Kamchatka.

A greatly enhanced probability for below normal precipitation (50%-30%-20%) is forecast for southeast China, surrounded by more weakly enhanced probabilities for below normal precipitation in large additional portions of southern and eastern Asia, stretching from India, through southeastern Asia and China to Japan.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for southwestern Russia and small parts of Afghanistan and Iran.

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

An enhanced probability for below normal precipitation (45%-30%-25%) is forecast for part of Sumatra, surrounded by more weakly enhanced probabilities for below normal precipitation in additional portions of Sumatra and a small part of Malaysia.

A very greatly enhanced probability for above normal temperature (10%-30%-60%) is forecast for extreme northeastern Taiwan, surrounded by more weakly enhanced probabilities for above normal temperature in the remainder of Taiwan, and much of eastern, southeastern, and southern Asia, stretching from southern Pakistan through India, the smaller countries of southeast Asia, China, Korea and Japan.

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

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for parts of India and Sri Lanka.

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

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for part of the Philippines and much of Indonesia.

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

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for southwest Russia, near the border of Iran.

December-January-February Year:

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for parts of Afghanistan, Pakistan, western China and Russia.

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

A greatly enhanced probability for above normal precipitation (15%-30%-55%) is forecast for certain tropical Pacific Islands in the western Pacific Ocean.

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for much of the Philippines and part of Malaysia.

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for Koror, Palau Island.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for two small portions of eastern Russia.

A greatly enhanced probability for below normal precipitation (55%-30%-15%) is forecast for southern Japan, as well as part of southeast China, surrounded by more weakly enhanced probabilities for below normal precipitation in additional portions of Japan, South Korea, and eastern China.

An enhanced probability for below normal precipitation (45%-35%-20%) is forecast for the Maldives (south of India), surrounded by more weakly enhanced probabilities for below normal precipitation in southern India.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for southern Myanmar and portions of Thailand, Malaysia, and Indonesia.

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

An enhanced probability for above normal temperature (20%-35%-45%) is forecast for northeasternern China and southeastern Russia, surrounded by more weakly enhanced probabilities for above normal temperature in additional limited portions of adjacent Russia and China.

An enhanced probability for above normal temperature (25%-30%-45%) is forecast for southwest Russia, surrounded by more weakly enhanced probabilities for above normal temperature in additional portions of southwest Russia near the border of Iran.

A greatly enhanced probability for above normal temperature (15%-30%-55%) is forecast for northern Myanmar, surrounded by more weakly enhanced probabilities for above normal temperature in much of the remainder of southeast Asia, stretching westward to India and northeastward to through eastern China southeast Mongolia.

A greatly enhanced probability for above normal temperature (15%-30%-55%) is forecast for Yap Island of the Federated States of Micronesia, surrounded by more weakly enhanced probabilities for above normal temperature in Guam, United States, and more of the Northern Mariana Islands.

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

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

Slightly enhanced probabilities for near normal temperature (35%-40%-25% and 25%-40%-35%) are forecast for most of Indonesia and the Philippines.

An enhanced probability for below normal temperature (45%-35%-20%) is forecast for eastern Russia, surrounded by more weakly enhanced probabilities for below normal temperature in significant additional areas of eastern Russia.

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

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for northwest Mongolia and the adjacent portion of central Russia.

January-February-March  Year:

An enhanced probability for above normal precipitation (25%-30%-45%) is forecast for west-central Siberia (Russia), surrounded by more weakly enhanced probabilities for above normal precipitation in additional portions of west-central Russia.

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

Slightly enhanced probabilities for above normal precipitation (30%-30%-40%) are forecast for northern portions of Pakistan, India and Afghanistan.

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

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

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

Slightly enhanced probabilities for near normal precipitation (25%-40%-35%) are forecast for part of the Philippines, Brunei, Malaysia, and part of Indonesia.

Slightly enhanced probabilities for below normal precipitation (40%-35%-25%) are forecast for southern Russia, north of Afghanistan.

A greatly enhanced probability for below normal precipitation (50%-30%-20%) is forecast for South Japan, as well as Taiwan and extreme southeastern China, surrounded by more weakly enhanced probabilities for below normal precipitation in additional portions of Japan, China and the northern Philippines.

Slightly enhanced probabilities for below normal precipitation (40%-30%-30%) are forecast for Bhutan, extreme eastern India, and parts of Myanmar, Bangladesh, and southern China.

An enhanced probability for below normal precipitation (45%-30%-25%) is forecast for southern India and Sri Lanka, surrounded by more weakly enhanced probabilities for below normal precipitation in an additional portion of India.

Slightly enhanced probabilities for below normal and near normal precipitation (40%-40%-20%) are forecast for portions of Thailand, Malaysia and more of Indonesia.

An enhanced probability for above normal temperature (25%-30%-45%) is forecast for part of Siberia (Russia) and northeastern Mongolia and northeastern China, surrounded by more weakly enhanced probabilities for above normal temperature in additional portions of those three countries.

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

An enhanced probability for above normal temperature (25%-30%-45%) is forecast for extreme North Korea, adjacent northeastern China and eastern Russia, surrounded by more weakly enhanced probabilities for above normal temperature in additional portions of those countries but also stretching southwestward through much of southern China through most of India.

A very greatly enhanced probability for above normal temperature (10%-30%-60%) is forecast for Yap Island of the Federated States of Micronesia, surrounded by more weakly enhanced probabilities for above normal temperature in the Northern Mariana Islands, and Guam (of U.S.).

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

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for a small part of west-central China.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for Taiwan, much of southeast Asia and much of Indonesia.

Slightly enhanced probabilities for near normal temperature (25%-40%-35%) are forecast for part of Sri Lanka and southern India.

An enhanced probability for below normal temperature (45%-30%-25%) is forecast for part of northern Siberia (Russia), surrounded by more weakly enhanced probabilities for below normal temperature in additional portions of Siberia, Russia.

Slightly enhanced probabilities for below normal temperature (40%-35%-25%) are forecast for eastern Russia, including Kamchatka.

Slightly enhanced probabilities for below normal temperature (40%-30%-30%) are forecast for small parts of Afghanistan, Pakistan and Iran.

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

To top   Back