The increasing storm track intensity in the U.S. bring brief cold pulses but generally not in high energy demand areas for home heating. Nationally, heating demand increases to near normal after early January.
During the next 2 weeks prohibitive precipitation amount is forecast across the West U.S. The Canadian Ensemble indicates large areas of >12 in. of liquid precipitation centered on northwest California and the Sierra Nevada Mountains. Conservative estimates range to >20- in. of water in favored areas of these two locations.
Latest 1-2 week outlooks indicate a dry and hot pattern developing across Argentina to far Southeast Brazil. In Northeast Argentina, a large area of deep layer soil moisture deficits is present. The combination of the forecast and deep layer soil moisture condition will lead to an Argentina flash drought by the middle third of January.
Causal of the recent polar vortex event into the U.S. was the combination of persistent high latitude blocking high pressure related to the warming influence of the upper atmospher caused by farther north open water during winter, warm water zones of the Northeast Pacific and western North Atlantic basins whose attendant upper air patterns force susceptibility of polar vortex events in North America and cross-polar flow of frigid Siberian arctic air making this polar vortex event even stronger.