Global Precipitation & Temperature Outlook for November 2016
November 3, 2016
Overview
The November 2016 Outlook calls attention to a vast expanse of exceptionally warmer temperatures forecast in the US Midwest and northward through Canada. Noteworthy in the precipitation forecast for the month: moderate to exceptional dry anomalies trace a wide path along South America's northern Pacific coast. (For data sources see "About This Blog Post" below.)
Temperature Outlook
There's no looking away from the big red blob that encompasses much of central North America in the temperature map below, indicating a forecast of exceptionally hotter temperatures for a vast expanse of the US Midwest and Ontario, Manitoba, and Saskatchewan, Canada. An anomaly such as this is beyond what one would expect to see only once every 40 years. Radiating outward from the blob, moderate to extreme temperature anomalies - shown in orange and red - bleed across much of Canada and reach to the US East Coast and Gulf, leaving only Florida and parts of the West untouched.
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.
Looking across the Atlantic to Africa, large pockets of exceptional warm temperature anomalies are forecast in coastal West Africa, around the Gulf of Guinea, and in Madagascar. Temperature anomalies may be especially severe or widespread in: southern Western Sahara, Mauritania, Sierra Leone, Liberia, Togo, Benin, southeast Nigeria, Cameroon, Equatorial Guinea, Gabon, and northern Congo. Exceptionally cooler temperatures are expected in northeastern South Sudan.
Though normal temperatures are forecast for much of India, exceptionally warmer conditions are expected to dominate India's southern tip and Sri Lanka.
Moderate to exceptional warm anomalies are also forecast for: eastern Iran; western China including the Tibetan Plateau, and Yunnan in the south; Myanmar; Southeast Asia; and Malaysia, Indonesia, and the Philippines.
Precipitation Outlook
A wide swath of exceptional dry anomalies traces a path along South America's northern Pacific coast from Colombia, through Ecuador and Peru, becoming less severe in southern Peru and into western Bolivia. Moderate to severe wet anomalies are forecast for western Paraguay, northern Bolivia, central and northern Brazil, and Venezuela, with pockets of extreme anomalies in Venezuela. Exceptionally wetter than normal conditions - shown in dark blue - are forecast in Chilean Southern Patagonia.
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.
In Africa, a dark red pocket in southern Ethiopia stands out, indicating a forecast of exceptional dry anomalies, with anomalies of lesser severity forecast for the rest of the country and scattered to the west.
Primarily moderate dry anomalies are expected in much of Saudi Arabia, in southern Iraq, and in Iran south and east of Tehran. Dry anomalies of varying severity are also evident stretching across eastern Russia.
Wetter than normal conditions are forecast in: northwestern Turkmenistan; western Uzbekistan; central and northern Kazakhstan into Russia; central Vietnam; the Malay Peninsula; Java; eastern Borneo; and northern Australia.
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, 2016 which includes forecasts for November 2016 through July 2017 based on NOAA CFSv2 forecasts issued October 25 through October 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.