Seemed like spring yesterday with a record high of 63° at O'Hare, just 4° shy of the all-time January record. Illinois was one of a dozen states to record record highs. Record highs were reported from Texas to Wisconsin. Cold air will come crashing in today riding gusty northwest winds. By Friday morning we could see lows dip to or just below zero. While Arctic air will visit the next few days there is hope for a warm up next week and beyond. The North Atlantic Oscillation Index is forecast to trend positively for the last day of January and the first few days of February. The NAO is an meteorological index that often correlates well with winter weather. A positive NAO index usually means a more subdued and milder weather pattern while a negative NAO index tends to indicate a colder, stormier pattern.
The long range outlook from the Climate Prediction Center agrees with the positive index forecast and is calling for above average temperatures for much of the contiguous US for the start of February through almost the middle of the month. The Chicago area is outlooked with between a 40-50% probability of above average temperatures.
The long range forecast of milder weather should be no surprise. There have been nearly 4 times more record highs set in the US so far this year compared to record lows. 1,327 record highs have been reported versus 318 record lows. Locally, we have seen something similar. There have been just 13 days with below average temperatures so far this winter but 47 days with above average temperatures.