Drought Has Diminished & Warmer Pattern Begins
About Average Never Felt So Good
Our high of 70° at O'Hare Thursday was the warmest we've seen in ten days. It matched the average high of 70° for the date but the chilly low of 41° yesterday morning meant that overall Thursday was below average. It was the tenth straight day with below average temperatures.
We will be working our way back to average and even above this weekend and into next week. Today's highs should again nudge to near 70° but a light breeze off the lake will keep highs in the middle 60s lakeside.
A Dent In The Drought
The latest analysis from the U.S. Drought Monitor shows the drought has diminished in northern Illinois. The area of the state in a moderate drought dropped by almost half compared to last week. 12% of Illinois on May 4th was in a moderate drought but the latest report has 6.58% in a moderate drought. Last week just over 43% of the state was abnormally dry but that has dropped to just over 25%. These are welcome improvements but more rain is needed in some of the parched parts of the state. O'Hare is running 1.58" below average for rainfall so far this Month and 5.82" below average since March 1st.
The GFS model suggests several chances of rain over the next ten days. The first few this weekend look to bring just light rainfall. Heavier rainfall could come towards the end of next week.
The GFS model spits out just about a tenth of an inch of rain through Tuesday morning for most of northern Illinois. Heavier rain could fall in central and southern Illinois with well over an inch of rain possible there in some spots.
Our drought may have diminished here but the drought situation remains dire out west. The areas out west in a moderate or exceptional drought increased by nearly 1% compared to last week while the areas in a severe and extreme drought decreased slightly. The situation is still very serious with almost 85% of the west in at least a moderate drought and nearly half of the region in an extreme drought. The drought outlook calls for the drought to persist or expand in much of the west through this summer.
Back To About Average
After three rounds of frost for some of us this week the temperature outlook is finally trending in the right direction towards a warmer end to May. Highs should hover right around average today through early next week. A couple of models try to slide us back into the 60s for highs Wednesday but I think most of next week should see highs into the 70s.
The warmest day of next week might be next Friday. The temperature anomaly forecast has most of the Midwest about 10° to 15° above average by then.
Highs by next Friday according to the GFS model should be well into the 70s with even a few spots tagging 80°.
Still Strong Warming Signal
After we finally get back to about average this weekend the pattern may get even warmer further into May. The longer range temperature probability forecasts again favor us for above average temperatures overall in the long term. The latest 6-10 day forecast favors us for above average temperatures overall from May 19th through May 23rd with higher probabilities here compared to yesterday's model run. The 8-14 day temperature probability forecast keeps us above average overall from May 21st through May 27th. Average highs for this period are in the lower to middle 70s.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecast has been consistently calling for a cooler pattern recently but the latest forecasts now favor the Chicago area for near normal temperatures for the end of May and start of June. The average highs for this period are in the middle 70s. The temperature anomaly forecast for the week ending May 28th has us outlooked to be about average overall. The forecast for the following week ending on June 4th has Chicago about average overall too.
Moving Back To Average May Rainfall
The longer range precipitation probability forecasts start off drier than average and then bring us to near normal rainfall towards the end of May. It is not the most robust rainfall forecast scenario but at least it is trending in the right direction. The latest 6-10 day forecast has Chicago favored for below average precipitation from May 19th through May 23rd. The longer range 8-14 day forecast also has us favored for about average precipitation overall from May 21st through May 27th. Most of western Illinois is favored in this second forecast to have above average rainfall overall.
Here is my 7 day forecast:
Today: Partly to mostly sunny High: 71 (65 lakeside)
Saturday: Partly to mostly cloudy, spotty showers Low: 50 High: 67
Sunday: Partly to mostly cloudy, spotty shower possible Low: 50 High: 70 (cooler lakeside)
Monday: Mostly cloudy, scattered showers Low: 55 High: 72 (cooler lakeside)
Tuesday: Partly to mostly sunny Low: 59 High: 76 (cooler lakeside)
Wednesday: Partly/mostly sunny, a few showers possible Low: 59 High: 76 (cooler lakeside)
Thursday: Mostly cloudy, sct. showers/t-storms possible Low: 61 High: 79 (cooler lakeside)