By Jim Noel, NOAA
The climate pattern is in a state of a flux. The La Niña pattern is weakening rapidly and will cause changes in weather patterns in the coming weeks and will result in lower confidence forecasting for a while during this change.
For April it looks like a warmer than normal month with normal or slightly below normal rainfall. However, there will still be big swings in temperatures so the last freeze will likely be in the normal range which is generally mid-April for southern Ohio to late April for northern Ohio. Evaporation rates will be above normal. This will all result in typical or earlier than normal planting. Beneficial rains will fall over most of the corn and soybean belts in April with the least rain likely in the eastern areas including Ohio. Over the next two weeks we expect 0.50 to 2 inches of rain with normal rainfall being 1.5 to just under 2 inches. Hence rainfall is forecast the next two weeks to be 50% to 100% of normal.
Soil moisture is in good shape in southern Ohio but is short in northern Ohio and needs to be watched carefully. Soil moisture will improve in most of the corn and soybean belts in April especially in the western half of the region which needs it. However, soil conditions in Ohio will likely stay the same or get a bit drier in April with above normal temperatures, above normal evapotranspiration rates and normal to below normal rainfall.
You can get all the latest information from the NOAA/NWS/Ohio River Forecast Center on drought risk here: https://www.weather.gov/ohrfc/DroughtBriefing
Seasonal information can be found here: https://www.weather.gov/ohrfc/SeasonalBriefing
The outlook during the growing season from May through summer looks like a warmer to hotter than normal summer. It is not clear whether this will be more of a consistent warm of whether it will be more of an impact to maximum temperatures above 95. We will keep you posted on that.
Rainfall confidence from May through summer is quite uncertain. With La Nina weakening that could offset some of the risk to the drier side. Hence, at this time the outlook supports normal to slightly drier than normal. In the summer 30-50% of rainfall comes from local soil moisture so it is important to watch your local soil moisture between now and Memorial Day as it will be a big driver in summer rains. Bottomline, we are aware there is some risk for growing drought risk into summer but confidence is still low in the outcome: https://www.cpc.ncep.noaa.gov/products/predictions/long_range/poe_index.php?lead=4&var=p. In summary, the tendency supports warmer weather overall through the planting and growing season with rainfall normal to below normal. There is some risk of expanding drought but confidence in that remains low at this time.