Global Precipitation & Temperature Outlook December 2019

Global Precipitation & Temperature Outlook December 2019

3 December 2019

OVERVIEW
The Outlook for December 2019 indicates that conditions throughout India will be much wetter than normal and will include exceptional anomalies. Temperatures along India’s east coast will be warmer than normal, as will temperatures in much of Indonesia. Central Africa is forecast to be cooler than normal.

PRECIPITATION OUTLOOK
In South Asia, much wetter than normal conditions are expected to blanket most of India with extreme to exceptional anomalies in Gujarat, Rajasthan, Maharashtra, Chhattisgarh, Jharkhand, Odisha, and West Bengal. Similar conditions are forecast for Bangladesh, and severe to extreme wet anomalies in Nepal and Bhutan. Central Pakistan will be somewhat wetter than normal reaching into southern Afghanistan.

Precipitation outlook. Reds indicate below normal monthly total precipitation. Blues indicate above normal monthly total precipitation. The darker the color, the more extreme the anomaly relative to a 1950-2009 climatic baseline. Colors are based on the expected return period of the anomalies.

Central Asia can expect some primarily moderate dry anomalies in Kyrgyzstan and Tajikistan and some moderate wet anomalies in Russia’s Western Siberian Plain and in its easternmost regions along the Bering and Chukchi Seas.

Tibet will be wetter than normal while parts of Xinjiang in northwestern China will be somewhat drier with moderate to severe anomalies reaching into northern Gansu. Southern Hebei will be moderately wetter than usual. Moderate to severe dry anomalies are forecast for southern Mongolia, and moderate dry anomalies for northern Inner Mongolia, southern North Korea, and pockets of central and northern Japan.

Some pockets of primarily moderate dry anomalies are expected in Southeast Asia, and moderately drier than normal conditions are forecast for Mindanao, Philippines. Drier than normal pockets are also forecast scattered throughout Indonesia and along New Guinea’s northern coast. Malaysian Borneo will be moderately wetter than the norm.

In Australia, New South Wales will be moderately drier than normal and moderate wet anomalies are forecast for southern Tasmania. Wet anomalies of varying intensity are expected in southern New Zealand. New Caledonia will be moderately drier than the norm.

Relatively normal precipitation conditions are forecast for Europe and for much of the Middle East, with moderate to severe dry anomalies in Saudi Arabia and wet anomalies in Yemen’s southwestern corner.

Moderately drier than normal conditions are forecast for northwestern Africa, pockets in nations along the northern Gulf of Guinea, and in South Africa, eastern Botswana, southern Zimbabwe, and southern Madagascar. Anomalies will be severe in Lesotho, northern South Africa, and pockets of Madagascar. Wet anomalies of varying intensity are forecast radiating from Uganda into surrounding nations and will be exceptional from eastern Uganda into western Kenya, northern Tanzania, Rwanda, Burundi, and into Democratic Republic of the Congo. Wet anomalies are also forecast for southeastern Ethiopia and northeastern Somalia.

In South America, wet anomalies will reach through the northwest from central Peru through Ecuador, Colombia, Venezuela, and Guyana. Wetter than normal conditions are also expected centered in Paraguay and reaching well into south-central Brazil and into southeastern Bolivia. Primarily moderate dry anomalies are forecast for Uruguay and nearby regions of Argentina and Brazil, and in southwestern Bolivia and pockets of eastern Brazil.

Pacific Central America will be wetter than normal with widespread anomalies in Panama. Moderately drier than normal conditions are forecast in southern Baja, Mexico and across the Gulf of California well into mainland west-central Mexico.

In the U.S., California and Nevada will be moderately wetter than the norm with some severe wet anomalies in western Nevada. Moderate wet anomalies are forecast in Iowa’s northeastern corner reaching into southeastern Minnesota and southwestern Wisconsin. Alaska’s coast west of Barrow will be wetter than normal as will the Sustina River region in the southeastern part of the state.

TEMPERATURE OUTLOOK
Temperatures in much of southern, eastern, and Northeast India, as well as Sri Lanka, will be warmer than normal with anomalies reaching exceptional intensity in many regions including Sri Lanka, Andhra Pradesh, and Madhya Pradesh. A pocket of central Pakistan will be moderately warmer than normal as will northern Afghanistan. Some cool anomalies are expected in Nepal and Bhutan.

Warm anomalies are expected in Turkmenistan, Uzbekistan, southern Kazakhstan, Kyrgyzstan, and Tajikistan, and will be severe in Turkmenistan, southern Uzbekistan, and southern Kyrgyzstan. A wide band of moderate warm anomalies is forecast in Russia from the Ural Mountains into the Western Siberian Plain, and in an area surrounding Lake Baikal. Russia’s easternmost region will see warm anomalies that are more intense.

Warm anomalies of varying intensity are forecast for much of Mongolia, in northern China from Xinjiang through the Middle and Upper Yangtze River Basin, in Northeast China, and in western Yunnan. Areas with exceptional anomalies include Henan and Beijing. Southeast China will be moderately warmer than normal, including Taiwan. Warm anomalies in Hainan, however, will be severe. The Korean Peninsula will be moderately warmer than the norm while warm anomalies in Japan are expected to be more intense.

Temperature outlook. Reds indicate above normal monthly average temperature. Blues indicate below normal monthly average temperature. The darker the color, the more extreme the anomaly relative to a 1950-2009 climatic baseline. Colors are based on the expected return period of the anomalies.

Warmer than normal temperatures are forecast throughout mainland Southeast Asia and Malaysia, Indonesia, much of the Philippines, and Papua New Guinea. Anomalies will be intense in western Myanmar, central Philippines, Sumatra, Java, Borneo, and Sulawesi.

Much warmer than normal temperatures will reach into northern Australia in Top End, Northern Territory and from the Cape York Peninsula southward through eastern Queensland reaching Brisbane. Primarily moderate warm anomalies are expected in eastern New South Wales, and moderate cool anomalies along Victoria’s coast. Moderate to severe warm anomalies are forecast for Western Australia and northern New Zealand. New Caledonia will be moderately warmer than normal.

Temperatures in Europe are forecast to be relatively normal with some moderate warm anomalies. Primarily moderate warm anomalies are forecast for parts of the Middle East including eastern Turkey, Syria, western Iraq, and eastern Iran. Western Yemen will be exceptionally warmer than normal, and severe warm anomalies are expected in Azerbaijan.

Central African nations will be much cooler than the norm. Exceptionally warmer than normal temperatures are expected in Madagascar, northern South Africa, Liberia, coastal Cote D’Ivoire, Djibouti, western Somaliland, and pockets of Ethiopia. Severe warm anomalies are forecast for Botswana, Zimbabwe, southern Mozambique, and southeastern Kenya. Areas with a forecast of moderate warm anomalies include western and northern African nations, some pockets around the Gulf of Guinea, Angola, and southern Zambia.

Brazil’s central and eastern regions can expect severe to extreme warm anomalies. Moderate warm anomalies are forecast for the western Amazon region. Warm anomalies are also expected in pockets scattered throughout northern nations of the continent and in western Peru, western Bolivia, northern Chile, and parts of the Argentine Pampas. The central region of the continent will be cooler than normal including Paraguay and nearby regions of Argentina, Bolivia, and Brazil.

Much of Central America and the Caribbean will be warmer than normal with anomalies ranging from moderate to exceptional. Mexico, too, will see warm anomalies, in the south, across the center of the country radiating from Puerto Vallarta, and many of the northern states. Anomalies will be exceptional in Nayarit on the west coast. A cooler than normal pocket is forecast in Sonora.

In the U.S., moderately warmer than normal temperatures are forecast in the Southwest, the Plains States, and the Ohio River Valley. Intense warm anomalies are expected along Alaska’s northwestern coast and moderate warm anomalies in the western extremities. Moderate warm anomalies in the U.S. Upper Midwest will reach into southern Manitoba and Ontario, Canada.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

ABOUT THIS BLOG POST
Each week, ISciences processes an ensemble of 28 seasonal temperature and precipitation forecasts issued by the National Oceanic and Atmospheric Administration's Climate Forecast System Version 2 (CFSv2). We present our results in a proprietary weekly report titled Global Water Monitor and Forecast: Precipitation and Temperature Outlook. This blog post summarizes our Outlook released December 2, 2019 which includes forecasts for December 2019 through August 2020 based on NOAA CFSv2 forecasts issued November 24 through November 30, 2019.

Technical details:

  • Each CFSv2 forecast is bias corrected by:

    • Constructing probability density functions from CFSv2 hindcasts.

    • Fitting the hindcast probability distribution functions to a generalized extreme value distribution.

    • Using an inverse lookup to an extreme value distribution fitted to the observed temperature and precipitation record (Fan & van den Dool 2008, Chen et al. 2002).

  • The map colors depict the return period of the median forecast anomaly.

  • Regions where the interquartile range of the ensemble spans both above normal and below normal conditions are hashed as having uncertain direction.

  • Regions where the interquartile range of the ensemble divided by the median forecast is large (>0.4) are hashed as having uncertain magnitude.

  • Results are reported in terms of return period using a 1950-2009 baseline.

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