Mar 03 | Weekly Climate Review & Weather Forecast
We wrapped up February and climatological winter with another week of mild weather. Average temperatures this week ranged from the high 30s in northern Illinois to the high 40s in southern Illinois, between 3 and 12 degrees above normal. While the official numbers will be released next week, the preliminary average temperature for February is about 4 degrees above normal and would put last month in the top 20 warmest on record statewide. The combination mild January and February weather pushed climatological winter temperatures above normal as well.
We had another wet week across the state, with precipitation totals ranging from just over half an inch around Interstate 70 to over 3 inches in parts of southern and far northeast Illinois. Virtually the entire state has been wetter than normal since the start of the year, and all of the south seven counties have been 3 to 6 inches wetter than normal over that time. The wet winter took care of all drought concerns across the state, and this week’s US Drought Monitor was completely absent any drought or abnormal dryness in Illinois, the first time this has happened since June 2020. That’s the good news… the less good news is that the switch has flipped too far in southern Illinois, and much of the region is experiencing saturated soils and isolated flooding issues.
A strong and complex storm system is moving through the state on Friday, bringing more heavy rain and possibly strong winds to southern Illinois, and likely accumulating snow in northern Illinois. The storm will likely cause flash flooding in low-lying areas of southern and eastern Illinois, as soils are near or at saturation already. Once we get beyond today’s storm the rest of next week looks drier across the state. Looking farther out, there is growing confidence in a pattern switch to colder than normal conditions between the second and third weeks of March. While most folks are probably ready for spring, unseasonable cold could slow the rapid advance of spring phenology, which could reduce spring freeze risk that is already elevated because of our mild winter. On the other hand, cooler temperatures will not help with wet soils; and on that topic – outlooks show likely wetter than normal conditions to persist through the middle of March. So, whether we think March came in like a lion or lamb, the first half of the month looks cold and wet.