Global Precipitation & Temperature Outlook for January 2018

3 January 2018

OVERVIEW
Warmer than normal temperatures are indicated in the January Outlook for much of Europe, particularly Eastern Europe and European Russia. Wetter than normal conditions are expected in South America's northernmost nations and in Myanmar.

PRECIPITATION OUTLOOK
As seen in the precipitation forecast map below, wetter than normal conditions are expected across northern South America in Colombia, Venezuela, eastern Ecuador, Guyana, northwestern Brazil, and eastern Peru. Wet anomalies could be extreme in Colombia and Venezuela. Moderate wet anomalies are forecast for Paraguay, reaching into Brazil.

Dry anomalies are forecast in western Ecuador and could reach extreme intensity in the southwest. Primarily moderate dry anomalies are forecast in northwest and southeast Peru and northeast Brazil. A small pocket of western Salta Province in northwest Argentina is expected to be extremely drier than normal.

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… — 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.

Some wet anomalies are forecast for Central America, particularly Panama and Costa Rica.

January precipitation in Mexico and the US is expected to be relatively normal. Some modest dry anomalies are forecast for eastern Canada, and modest wet anomalies for western Yukon Territory.

In Europe, somewhat wetter than normal conditions are expected in the UK, pockets of Central Europe, Northern Europe, the Baltics, and European Russia. Wet anomalies are expected to reach across much of northern Russia. Primarily moderate dry anomalies are forecast for the southern portion of the Iberian Peninsula.

These moderately dry conditions will reach across the Strait of Gibraltar into much of Morocco and western Algeria. Some moderate dry anomalies are also expected around the Gulf of Guinea and the Horn of Africa. Tanzania and northern Zambia are forecast to be moderately wetter than normal.

Primarily moderate dry anomalies are forecast for Saudi Arabia and around the Persian Gulf; parts of Central Asia; northern India; and much of western and northeast China. Conditions may be more severe in eastern Tibet and northeast China.

Conditions in Myanmar are expected to be much wetter than normal, with anomalies reaching exceptional intensity. Moderate wet anomalies are forecast scattered throughout Southeast Asia and the Pacific, across northernmost Australia, and North Island, New Zealand.

TEMPERATURE OUTLOOK
A vast stretch of warmer than normal temperatures clearly dominates the January forecast for Europe through much of Russia. Extreme to exceptionally hotter than normal temperatures are expected from Poland through Eastern Europe, into the Baltics and southern Scandinavia, and well into Russia's western half. Anomalies of generally lesser intensity - though still moderate to severe - surround the aforementioned region, reaching from western Europe to the Sea of Okhotsk in eastern Russia.

In the Middle East moderate to exceptional warm anomalies are forecast for Turkey, Syria, Iraq, and western Iran. Somewhat cooler than normal conditions are expected in the southern Arabian Peninsula.

Primarily moderate warm anomalies are forecast for Central Asia. Severe warm anomalies are predicted for southern India and India's Far Northeast; much cooler temperatures are forecast near Nepal.

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… — 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.

Much of western and northern China and southern Mongolia will be warmer than normal, with exceptional anomalies expected across Tibet. Moderate to extreme warm anomalies are forecast for Myanmar, and anomalies of similar severity are expected stretching from Indonesia through the southern Philippines and across Papua. Eastern Australia will be moderately warmer than normal and conditions in Tasmania and New Zealand may be slightly more intense.

Cooler than normal temperatures are forecast for central Africa, extreme warm anomalies along coastal regions of the Gulf of Guinea, and moderately warmer than normal conditions in South Africa.

Moving to the forecast for North America, much of the western US will be warmer than normal, particularly Utah, with anomalies ranging from moderate to extreme. Mild to moderate warm anomalies are expected in Canada west of Hudson Bay. In west-central Mexico exceptionally hotter than normal temperatures are forecast for the state of Nayarit, and warm anomalies of lesser severity are predicted for Baja and northern Mexico.

In South America, warm anomalies are forecast for eastern Brazil and may be extreme in Bahia. Severe warm anomalies are expected in southwestern Bolivia. Cooler than normal temperatures will prevail in Paraguay and across the border into Bolivia, Argentina, and Brazil. Central Venezuela is also forecast to be cooler than normal.

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 January 2, 2018 which includes forecasts for January 2018 through September 2018 based on NOAA CFSv2 forecasts issued December 25 through December 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.