The NWS Climate Prediction Center just released their outlook for the month of November and the 3-month outlook for November to January and beyond. There is nothing exciting to report for Illinois. We are in the “E.C.” region for equal chances of above, below, and near-average conditions for both temperature and precipitation in November. There is an increased chance of above-average temperatures in the November-January time frame.
Here is what they say in their forecast discussion. On a side note, the NWS text products are sent in all caps, a carryover from the teletype days. It’s quaint and annoying. ENSO refers to the El Nino-Southern Oscillation.
THERE ARE ONLY VERY WEAK INDICATIONS FOR CLIMATIC ANOMALIES FOR THIS NOVEMBER. THE HISTORICAL SKILL OF TOOLS IS QUITE LOW IN THE LATE FALL, ESPECIALLY SO DURING ENSO NEUTRAL CONDITIONS. THE STATE OF SOIL MOISTURE HAS LITTLE IMPACT ON TEMPERATURES OR PRECIPITATION WHEN SUN ANGLES ARE LOW, AND HENCE DOES NOT PLAY A ROLE IN THIS FORECAST. THIS FORECAST IS PRIMARILY BASED ON PROBABILISTIC FORECASTS FROM THE NMME AND IMME WITH SOME ADDITIONAL CONSIDERATIONS TO LONG TERM TEMPERATURE TRENDS.
The NMME and IMME are two sets of model ensembles. NMME stands for the National Multi-Modal Ensemble forecast and is based on 5-7 models. I have used their results in the past with caution. Right now they are one of the few viable forecasts in town, because the current ENSO-neutral conditions in the Pacific makes it impossible to use any kind of statistical forecast based on El Niño or La Niña events.
The NMME forecast for precipitation over the next few months suggest near-average precipitation in northern Illinois and above-average precipitation in southern Illinois in November. Below-average precipitation prevails in the December while January reverts back to the pattern seen in November (average – north, wet – south).
The NMME forecast for temperature shows widespread above-average temperatures in November across the central US. Near-average temperatures are forecasted for December. Remarkably, above-average temperatures are expected to prevail in Illinois from January through March.