The largest surprise in forecast models is the increase in rainfall in the 15-day outlook for Northeast Argentina, Uruguay, and Southeast Brazil. The AIFS forecasts consistent rains piling to several to 6 inches due to a quasi-stationary frontal boundary in the region.

Massive amounts of thunderstorm activity is percolating in the western Gulf of Mexico. A widening area of thunderstorms along a low-pressure trough emerges, lasts for many days, and produces 15-20 in. of rain near the Texas/Louisiana coast.

The southeast quadrant of Europe to Southwest Russia has averaged 3-6C warmer than normal during the past week with attendant widespread dryness. The latest 15-day forecasts widen the anomalous heat and dryness in Europe to Western Russia!

On Monday, a large area of damaging wind is likely from northeast Nebraska to southern Minnesota. Severe storms rumble across Michigan on Tuesday. Extreme heat and humidity precede the severe thunderstorm outbreaks.