Drought Deepens In Chicago & Midwest
Will May Bring Much Needed Rain?
O'Hare has seen rain the past two days but it has only amounted to a little less than a tenth of an inch. More rain is needed to put a dent in the expanding drought. At least a portion of nine counties in northern Illinois are now in a moderate drought that includes Chicago and all of Cook County. Rainfall is down 2.55" from average for April at O'Hare and down nearly 4" since March 1st. The total area now experiencing a moderate drought in Illinois has nearly doubled compared to a week ago. The area now considered abnormally dry and on the verge of slipping into a moderate drought has more than doubled over the past week.
A map that shows the percentage of normal rainfall for the past sixty days shows the most parched places in northern Illinois are focused in and around Chicago. Much of the area has seen just 50% of average rainfall during the period from Joliet to Chicago all the way north into southern Wisconsin and all the way west to near Rockford.
Some surrounding states have also seen a surge in their area now considered to be in a moderate drought. Nearly 9% of Indiana is now in a moderate drought. That is nearly four times more than a week ago. Nearly 23% of Wisconsin is now in a moderate drought compared to under 1% just a week ago.
Nearly half of the Midwest is abnormally dry with almost 20% of the region in a moderate drought and 1% in a severe drought
The area of the country where the drought is most dire is in the west. Over 80% of the region is in a moderate drought, nearly 65% in a severe drought, over 43% in an extreme drought and over 21% in an exceptional drought. The percentage of area for each of these drought levels has increased compared to a week ago.
The dry conditions could create a problem here tomorrow. Gusty winds on Saturday combined with relative humidity levels dropping to between 25-30% means an elevated fire risk. The National Weather Service is warning that this could lead to an increased risk for rapid brush fire spread.
Today's brisk breeze off the lake with gusts to near 30 mph will keep us cooler than average with highs failing to get out of the 50s for many. Saturday's highs should surge to near 80° or about 25° warmer than today. Southwesterly winds will gust to near 40 mph.
Average highs for today's date are around 65°. Look for highs today to range from just the lower 50s lakeside to near 60° well west and southwest of the city. Most of us should have highs in the middle to upper 50s.
So April ends on a cool note but May starts off much warmer on Saturday. Highs should at least be well into the 70s but I expected many spots will tag 80°.
The temperature anomaly forecast for tomorrow afternoon has temperatures here around 15° to 20° above average. Most of the Midwest will enjoy anomalous warmth on Saturday. That warmth will stretch from Chicago to Minneapolis and westward to Denver.
A Need For More Spring Showers
Drought ridden areas are desperate for some rain but little will come this weekend. A few scattered showers and thunderstorms are possible late Sunday especially north of the city. The GFS model shows the best chance of rain will come on Monday. Most next week may end up being dry. There is another chance for rain next weekend.
The GFS model precipitation accumulation forecast through Tuesday morning spits out about a tenth of an inch to nearly a half inch of rain here. The higher rainfalls in that range are expected near the Wisconsin border.
Summery Saturday & Sunday
The hourly temperature meteogram compares many different forecast models. The warmest days of the next seven will fall over the weekend. It will feel just like late June or early July. We will really appreciate this weekend's warm up after our cool end to April today.
Long Range Flip In Temperature Forecast
The signals recent long range temperature probability forecasts had been consistently suggesting above average temperatures overall but that has changed. The latest forecasts drop us back below average. The latest 6-10 day forecast has us outlooked for cooler than average temperatures overall from May 5th through May 9th. The 8-14 day temperature probability forecast has us favored for staying below average overall from May 7th through May 13th. Average highs for the middle of May are around 70°.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecast is also signaling a cooler than average pattern for the middle two weeks of May. The temperature anomaly forecast for the week ending May 14th has us outlooked to be below average overall. The forecast for the following week ending on May 21st has Chicago below average overall too. Average highs for this period are in the upper 60s to lower 70s.
Drought Relief In Longer Range Forecast?
The long range precipitation probability forecasts have us trending towards a possibly more active pattern by the middle of May. The latest 6-10 day has Chicago favored for about average precipitation from May 5th through May 9th. The longer range 8-14 day forecast though has us favored for above average precipitation overall from May 7th through May 13th.
Here is my 7 day forecast:
Today: Mostly sunny, cooler & breezy (gusts near 30 mph) High: 59 (53 lakefront)
Saturday: Mostly sunny, warmer & windy (gusts near 40 mph) Low: 43 High: 80
Sunday: Partly to mostly cloudy, windy & warm, sct. t-storm late? Low: 60 High: 80
Monday: Mostly cloudy, scattered showers & t-storms Low: 59 High: 72 (cooler lakeside)
Tuesday: Mostly cloudy, scattered showers Low: 48 High: 59 (cooler lakeside)
Wednesday: Partly to mostly sunny Low: 46 High: 61 (cooler lakeside)
Thursday: Mostly cloudy, scattered shower possible Low: 45 High: 62 (48 lakeside)