The following content was provided by meteorologist Gail Martell of MartellCropProjections.com:
As La Nina Fades, Weather Conditions Are Suddenly Different
The global winds and air pressure are in flux, as the La Nina fluctuation gradually fades away. Weather conditions in the United States and around the world have showed signs of change in April, opposite of March, as the La Nina effect has weakened. Below is a brief summary of how weather conditions have reversed in April:
Midwest Weather Shift: Showers have significantly increased in recent weeks in Iowa, Nebraska, Minnesota, South Dakota and North Dakota. At the same time, very dry April weather has occurred in the Eastern Midwest and Mid South. These changes reflect El Nino, along with much cooler weather in April, and frequent night frosts.
Drought Eases in Eastern Canadian Prairies: Precipitation has increased significantly in eastern Saskatchewan and Manitoba in recent weeks, easing severe drought. Temperatures have trended sharply cooler in April with frequent hard freezes. This is the opposite of prevailing March conditions.
Western Europe Rain Relief: Above-normal rains have developed this month in Europe. This ends a period of intense drought in France, United Kingdom, Spain and Italy. While we do not have corroborating evidence that La Nina causes drought, it would appear so. The stretch between mid-January and the end of March was incredibly dry.
China Suddenly Warmer in Northeast Corn Belt: Warming in April in the key Northeast corn provinces is a sharp reversal from March, when cold prevailed. Rainfall has been mostly absent, both in Northeast China and winter wheat zone on the North China Plain, suggesting a lingering La Nina signal still exists.
European Russia Suddenly Warm and Dry: Sudden heat and dryness has developed in April in European Russia, an area that was persistent wet and cold through mid March. The new weather pattern is favorable for warming and drying of soggy fields, laden with heavy snowmelt. On the other hand, poor spring planting conditions from drought are anticipated in Russia’s eastern grain belt in Urals, Siberia and eastern Volga. A massive ridge of high pressure has been in control of weather in April.
Parana Rainfall Ends Long Drought: Parana Brazil's top corn state finally received generous rainfall last week. The came after a prolonged severe drought from December-March that damaged soybean and corn production. The heavy rainfall will not replenish parched field conditions. Thus the winter corn harvest is still in jeopardy. Conditions previously this month were exceptionally hot in Parana and throughout Eastern Brazil. The point is that drought inspired by La Nina may finally be ending, as the La Nina signal fades away. The new forecast continues wet this week.
Eastern Australia April Dryness: Eastern Australia is very sensitive to the ENSO signal, benefiting from heavy rainfall when the La Nina is in effect. Summer growing conditions December-February were exceptionally wet, contributing to a favorable summer crop harvest. Australia wheat production also set a record from very generous growing season rainfall. However, as the La Nina has waned, rainfall has tapered off. April has suddenly become dry in New South Wales, Victoria and South Australia.