Increasing Variability In Rainfall

Jun 06, 2018

By Jim Noel

Ohio Weather Pattern June 4, 2018

As summer nears, the weather pattern supports an increasing risk of big differences in rainfall totals from too wet to too dry.

There is a growing risk of a heat dome developing off the drought area in the south central to southwest parts of the U.S. The heat dome will expand northeast into parts of the corn and soybean belt from time to time over the next several weeks. This means enjoy the cooler than normal weather this week. Storms will ride along the northern edge of the heat dome as it shifts north and south. This means locally heavy rain will be next to areas that get missed. The end result will be a wide variety of rainfall reports in June.

The June outlook calls for above normal temperatures and a wide variation in rainfall amounts.

Maximum temperatures do not look to exceed the 90-95 range on the hottest days due to overall decent soil moisture conditions so even though we expect above normal temperatures, extremely high temperatures do not look in the offering for Ohio.

Rainfall for the next two weeks will average close to normal of 2 inches but with a range from 0.25 inches in the driest areas to over 3-4 or more inches in the highest areas. See attached image from NOAA/NWS/Ohio River Forecast Center for more information on rainfall distribution across the entire corn and soybean belt.

Source: osu.edu

Video: Spring 2026 weather outlook for Wisconsin; What an early-arriving El Niño could mean

Northeast Wisconsin is a small corner of the world, but our weather is still affected by what happens across the globe.

That includes in the equatorial Pacific, where changes between El Niño and La Niña play a role in the weather here -- and boy, have there been some abrupt changes as of late.

El Niño and La Niña are the two phases of what is collectively known as the El Niño Southern Oscillation, or ENSO for short. These are the swings back and forth from unusually warm to unusually cold sea surface temperatures in the Pacific Ocean along the equator.

Since this past September, we have been in a weak La Niña, which means water temperatures near the Eastern Pacific equator have been cooler than usual. That's where we're at right now.

Even last fall, the long-term outlook suggested a return to neutral conditions by spring and potentially El Niño conditions by summer.

But there are some signs this may be happening faster than usual, which could accelerate the onset of El Niño.

Over the last few weeks, unusually strong bursts of westerly winds farther west in the Pacific -- where sea surface temperatures are warmer than average -- have been observed. There is a chance that this could accelerate the warming of those eastern Pacific waters and potentially push us into El Niño sooner than usual.

If we do enter El Nino by spring -- which we'll define as the period of March, April and May -- there are some long-term correlations with our weather here in Northeast Wisconsin.

Looking at a map of anomalously warm weather, most of the upper Great Lakes doesn't show a strong correlation, but in general, the northern tiers of the United States do tend to lean to that direction.

The stronger correlation is with precipitation. El Niño conditions in spring have historically come with a higher risk of very dry weather over that time frame, so this will definitely be a transition we'll have to watch closely as we move out of winter.