U.S. Cold Breaks in the 11-15-Day Period

Fig. 1-2: Mega-cluster Ensemble “most likely” 11-15-day temperature anomaly forecast across North America and the ECM ENS 15-day percent of normal precipitation outlook for North America.

Discussion: Unusually cold weather settles over the U.S. during the next 10 days. However, the cold is projected to break after 10 days retreating to Canada while much of the U.S. is temperate (Fig. 1). The North America 15-day precipitation forecast maintains a dry pattern with the only significant precipitation across the Gulf of Mexico and Florida (Fig. 2). Consequently, U.S. drought is worsening and mid-continent river levels stay below low water.

In South America, rainfall forecasts are variable with each model run. Consequently, reliance on the mega-cluster ensemble is recommended. In the 5-day forecast the Argentina outlook is very dry (Fig. 3) and somewhat warmer than normal. Wet weather is along the Argentina and Brazil Coast. In the 6-10-day period the “most likely” rainfall scenario is showery across the Southern Brazil crop areas while Argentina is marginally dry (Fig. 4). The extended-range forecast returns a strong dry pattern to Argentina and Paraguay while North/East Brazil are wet (Fig. 5). The 11-15-day forecast is consistent with where the rainfall climate is expected to trend for upcoming summer.

Fig. 3-5: The mega-cluster ensemble 15-day “most likely” rainfall forecast across South America.

Last week was wet again across Southeast Australia. However, mega-cluster ensemble “most likely” precipitation forecasts are abating the wet risk in the rain-soaked East. The forecast for this week is much drier in the East while wet risk is the strongest northwest and central continent (Fig. 6). In the 6-10-day period, most of the wet weather stretches across the northern continent and (also) Victoria to Tasmania (Fig. 7). The 11-15-day forecast maintains the northern continental wet pattern while dryness is forecast across the South (Fig. 8).

Fig. 6-8: The mega-cluster ensemble “most likely” 15-day percent of normal rainfall forecast across Australia.