Global Precipitation & Temperature Outlook for August 2016

Overview
The August forecast indicates scattered precipitation anomalies - both drier and wetter than normal - with a few isolated anomalies of exceptional value (greater than 40 years). Warmer than normal temperature anomalies are, once again, expected to be widespread and extreme (20 to 40 years) or exceptional (greater than 40 years) in many parts of the world. (For data sources see "About This Blog Post" below.)

Precipitation Outlook
Conditions of exceptional dryness are forecast in eastern Nepal, including Kathmandu, and along the border of Nepal and Tibet between Annapurna and Mt. Everest. Just south of Nepal, an isolated area in northeastern Uttar Pradesh into northwestern Bihar, India is also expected to be exceptionally drier than normal. Likewise, similar conditions are forecast in a small area of northwestern Karnataka, India near Goa.

Extreme dry anomalies are forecast for Brazil's northeastern State of Amapá.

Elsewhere, the August Outlook predicts moderate to severe dry anomalies in: much of Myanmar; western Thailand; a band from eastern Central African Republic through South Sudan and parts of Ethiopia into Somaliland; the Caucasus; Acre and western Amazonas, Brazil; and the US Northwest.

Exceptionally wetter than normal conditions are forecast in eastern Kyrgyzstan and in the Taklamakan Desert in western China. Moderate to extreme wet anomalies are predicted for: the island of New Guinea; western Mongolia; eastern Honshu, Japan; Russia between the Pecora and Kara Seas; from Arizona, US through Sonora, Mexico; Guatemala; Honduras; and western Colombia.

Temperature Outlook
As is evident in the bright red patches on the August temperature forecast map below, vast expanses of northern South America, North Africa, Saudi Arabia, and Southeast Asia are predicted to experience extreme to exceptional warm anomalies.

Notable warm anomalies are forecast for the southeastern US, with exceptional anomalies expected in Louisiana and Arkansas and extreme anomalies in Florida.

Moderate to extreme warm anomalies are forecast for the Yucatan Peninsula and much of Central America.

Eastern Europe and European Russia are expected to have moderate to severe warm anomalies.

Warm anomalies of varying severity are also forecast for: Turkey, southern Iraq, United Arab Emirates, Angola, Namibia, Madagascar, southern India, Sri Lanka, Bangladesh, Malaysia, Indonesia, Hainan, and Taiwan.

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, 2016 which includes forecasts for August 2016 through April 2017 based on NOAA CFSv2 forecasts issued July 25 through July 31, 2016.

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.