Global Precipitation & Temperature Outlook for August 2017

3 August 2017

Overview
The August forecast indicates a few areas that will see drier than normal conditions, including northern India from Gujarat through the center of the country; and, along the southern and eastern shores of the Black Sea. But once again it is the temperature forecast that commands attention with vast areas of northern South America and the Middle East forecast to be exceptionally hotter than normal, as well as many other parts of the world with a forecast of warm anomalies of varying severity.

Precipitation Outlook
Northern Turkey is expected to see moderate to extreme dry anomalies which will reach even greater intensity around the eastern shore of the Black Sea in Georgia. Moderate dry conditions are forecast for eastern Ukraine, reaching across the border into a few Russian oblasts.

Conditions in parts of India's northern half are expected to be drier than normal. Severe dry anomalies are expected in Gujarat, and primarily moderate to severe dry conditions will reach from there into north-central India, including Madhya Pradesh, Rajasthan, and Uttar Pradesh. A pocket in northeastern Uttar Pradesh could reach exceptional severity. Dry conditions ranging from moderate to severe are also forecast for northwestern Pakistan.

Moderate to severe dry conditions are forecast for northwestern Peru, western Ecuador, and in far western Brazil in the States of Acre and Amazonas.

Moderate dry anomalies are forecast for Somaliland.

Wet anomalies of moderate to severe intensity are forecast for: western Texas, northern Argentina, western Cameroon, southeastern Tanzania, and Papua New Guinea. Wet anomalies of lesser intensity are forecast in southern China.

Temperature Outlook
The dark red regions on the temperature map below indicate a forecast of exceptionally hotter temperatures. Particularly noticeable are the Amazon Basin and much of the Middle East.

Severe to exceptional warm anomalies are expected across northern South America with particular extent and intensity in the Amazon Basin. Anomalies are also forecast for northern Chile and southwestern Bolivia, and generally less intense warm anomalies expected in Uruguay; Rio Grande do Sul, Brazil; and Tierra del Fuego.

Severe to exceptional warm anomalies are also forecast throughout much of central America which may be especially intense in Costa Rica and Panama. Similarly, western Cuba, Jamaica, the Yucatan Peninsula, southern Mexico, southwestern Mexico, and the Baja Peninsula are all forecast to experience severe to exceptional warm anomalies.

Moving north, nearly all of Canada and the western US will see moderate to occasionally extreme warm anomalies. Warm anomalies of greater intensity are expected in Maine, Canada's Maritime Provinces, and in southern Florida.

Most of the Middle East is expected to be much warmer than normal, particularly Saudi Arabia, Iraq west of the Euphrates, Kuwait, along the Persian Gulf in Iran, Syria, Lebanon, and eastern Turkey.

In Europe, relatively normal temperatures are expected in Northern and Western Europe, but moderate to extreme warm anomalies are forecast for Italy and other nations around the Adriatic Sea, northern Serbia, Austria, Hungary, Slovakia, Romania, and western Ukraine, with the most intense conditions in southern Italy and Albania.

Many parts of Africa will be warmer than normal but exceptionally warmer than normal conditions are forecast for: Somaliland, northern Somalia, northeastern Sudan, the northern Ethiopian Highlands, southeastern Kenya, and southeastern Algeria. Anomalies from southern Africa into Madagascar will range from moderate to severe and may be most widespread in South Africa.

Moderate to extreme warm anomalies are forecast in India's southern half and the far north, and in Bangladesh. Warm anomalies are expected to blanket much of Southeast Asia as well, but of slightly lesser intensity. In East Asia warm anomalies will reach exceptional severity in southern Tibet. Warm anomalies of varying severity are also forecast for: southern China; northeast China; Taiwan; across a vast stretch of southeastern Russia; and along Australia's Sunshine Coast north of Brisbane.

Moderate to severe cool anomalies are expected in: Colorado and central Arizona; northern Sonora, Mexico; western Afghanistan; pockets of central Iran; eastern Tajikistan; and south-central Democratic Republic of the Congo.

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 August 2, 2017 which includes forecasts for August 2017 through April 2018 based on NOAA CFSv2 forecasts issued July 25 through July 31, 2017.

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.