The NWS Climate Prediction Center has released the new outlooks for March as well as March-May.
One of the key things to come into play is the status of La Niña in the Pacific Ocean. A La Niña event occurs when ocean temperatures are colder-than-normal along the eastern part of the Pacific Ocean basin. The associated ocean and atmospheric pattern tends to give us a wet spring in states along the Ohio River Valley. CPC states that “La Niña is likely to transition to ENSO-neutral conditions during March-May 2012.” That’s government-talk for saying that the La Niña event is fading fast and will be gone before the end of spring.
The outlook for March in Illinois calls for an increased chance of above-normal temperatures and above-normal precipitation. The outlook for March-May calls for an increased chance of above-normal temperatures throughout the state. However, it shows an increased chance of above-normal precipitation in the eastern half of the state while the western half has “equal chances” of above-, below-, near-normal precipitation.
The new outlook for June-August (maps below), the heart of the growing season, is for an increased chance of above-normal temperatures in southern Illinois and “equal chances” for the rest of the state. The entire state is in “equal chances” with respect to precipitation.
Just a note on “equal chances”. That’s the NWS way of saying that none of their forecasting techniques are indicating a higher risk of unusual temperature or precipitation patterns.