Global Precipitation & Temperature Outlook for November 2015

The November 2015 Outlook indicates the presence of exceptional anomalies in the forecasts for both precipitation and temperature. The temperature forecast, however, continues to dominate the narrative. (For data sources see "About this blog post" below.)

TEMPERATURE OUTLOOK
Now into its fourth quarter, 2015 continues to exhibit signs of exceptional and persistent heat. Oranges and reds light up the forecast (first map below) indicating moderate to exceptional hot anomalies. In the western hemisphere exceptional anomalies (greater than 40 years), shown in deep red, are expected in: the Great Lakes Region of the United States and in Florida; much of the Caribbean and Central America; Jalisco, Mexico; Brazil's Amazon region and north into Suriname and French Guiana; and, pockets  along the northern Pacific Coast of South America.

Elsewhere, exceptionally hot temperatures are expected in the United Kingdom, Scandinavia, much of India, Sri Lanka, Southeast Asia, Malaysia, much of Indonesia, the Philippines, Taiwan, northern China and along the East and South China Seas, the Korean Peninsula, and Japan. Cool anomalies of note are forecast for Central African Republic and South Sudan, and in Iraq. 

Temperature outlook for November 2015. 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.

PRECIPITATION OUTLOOK
Highlights of November's precipitation Outlook (see map below) include large areas of moderate to exceptional wet anomalies in East Africa, particularly Tanzania, Uganda, Kenya, and Ethiopia. Similarly, much of Central Asia and China may experience wetter than normal conditions. Parts of the US Southeast, Tennessee Valley, and Lower Mississippi Valley are expected to be wetter than normal, including: the Carolinas, Georgia, Alabama, Tennessee, Mississippi, Arkansas, and Louisiana. Other parts of the world forecast to see above average rainfall include: Colombia, Ecuador, southern Brazil, west-central Argentina, Iran and southwestern Australia.

Moderate to exceptionally dry conditions are forecast for northern Brazil, Suriname, and French Guiana. Eastern Europe may be a bit drier than normal, particularly Romania and Bulgaria.

Precipitation outlook for November 2015. 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.

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 November 2, 2015 which includes forecasts for November 2015 through July 2016 based on NOAA CFSv2 forecasts issued October 25 through October 31, 2015.

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 2008Chen 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.