May has been an especially active month with over 150 tornadoes so far causing localized damage to fields and infrastructure.
Temperatures across northern Minnesota and North Dakota have been trending 4 to 10 degrees above normal, with near to above normal temperatures elsewhere across the upper Midwest.
Crop soil moisture has benefitted from frequent rainfall the past several months, especially from Iowa south into the southern plains and southeastern United States.
The Palmer Drought Severity Index shows extreme drought conditions across Iowa with near normal conditions across Minnesota, North Dakota, and Wisconsin. Pockets of abnormally dry conditions persist in extreme northwest Minnesota and northeastern North Dakota.
Changing Weather Pattern
El Niño continues to weaken across the tropical Pacific Ocean. A transition to neutral El Niño-Southern Oscillation (ENSO) pattern is likely over the next several months. There is now a 70% chance La Niña will develop by late summer to early fall.
The emergence of La Niña would likely impact hurricane season and create conditions across our region much different from last winter. The wind sheer produced by La Niña affects hurricane formation in the Atlantic Ocean. It also tends to bring harsher winters to the Midwest. This is caused by the northern portion on the jet stream dipping southward allowing cold air from Canada to filter southward unabated. A series of clipper-type systems regularly form shaking loose more snowfall than normal.
Based on the potential impact of La Niña, the 90-day forecast is hinting at uncertainty. There is an equal chance of precipitation and temperatures either trending above or below normal. We will continue to watch how this pattern evolves.
