Fig. 1-2: Last week’s total percent of normal rainfall and daily soil moisture anomalies across South America according to NOAA. Discussion: Last week, a steady wet regime developed in Northeast Argentina (Fig. 1) where soil moisture conditions continue to improve (Fig. 2). However, most of Brazil observed below normal rainfall and widespread dry to drought soil moisture conditions continue and worsen. The 15-day outlook is dependent on the position of a strong subtropical high-pressure system quasi-stationary over Eastern Bolivia the next 10 days (Fig. 3) and shifting to Northwest Brazil in the 11-15-day period (Fig. 4). During the next 10 days, much of Brazil is drier and hotter than normal as drought accelerates. However, in the 11-15-day period, forecast models indicate an upper trough develops on the East Coast of Brazil and coupled with exceptional warm SSTA off the coast leads to widespread wet weather. For the moment, the showery East Brazil regime just-after mid-month is likely to expand westward into Central Brazil for the last third of December prior to regenerating drier than normal climate in early January. Fig. 3-4: The GFS ENS percent normal rainfall forecast for the next 10 days and 11-15-day period across South America.  

Fig. 1-2: Snow cover across Eurasia is above normal in Europe and Northeast China. The 15-day forecast erodes Europe snow cover while increasing in Russia. Discussion: Early meteorological winter chill spreads across Europe while an arctic air mass is developing in Russia. All of Russia is covered in snow while extending well into Europe (Fig. 1). The day-15 snow cover forecast indicates some of the Central/East Europe snow cover erodes while piling in Russia to sustain frigid air (Fig. 2). The 12Z GFS explodes arctic air across Western Russia this week (Fig. 3) expanding although not quite as intense in the 8-14-day period (Fig. 4). Western Europe starts this week cool, but moderation follows for all areas west of the early season snow cover.   Fig. 3-4: The 12Z GFS 1-7-day and 8-14-day temperature anomaly forecast is frigid across Russia extending to Eastern Europe and the Black Sea region.