The Drought Deepens
Severe Drought Develops For Some
The latest analysis from the U.S. Drought Monitor shows the drought has deepened in northern Illinois with some parched portions of our area now in a severe drought. The area of the state in a moderate drought did not change from last week and remains at 6.58%. What is troubling is now nearly 3% of northern Illinois is in a severe drought. That includes the north side of the city, northern DuPage & Cook counties, northeastern Kane county, all of Lake county and most of McHenry county. O'Hare is now down 2.49" of rain below average for May and 6.73" below average since March 1st.
It has been particularly dry over the past thirty days. Many of our northern suburbs have only received between about 10-20% of average rainfall for the period. An area more than twice that size has seen just 25-50% of average rainfall.
Indiana is faring much better at least for now. None of the state is in a drought. Just over 21% of the Hoosier State is considered abnormally dry. That is up a little over 1% compared to last week. If this area doesn't improve it could easily slip into a moderate drought.
The GFS model suggests several chances for mainly spotty showers and thunderstorms starting Saturday. Any rain would be welcomed but it isn't the more widespread, drenching type of rain to really make an impact on the drought.
The GFS model total rainfall forecast through Thursday afternoon spits out a range of rainfall. The lighter amounts of around a quarter inch is forecast south of the city, around a half inch in the city and up to a little more than eight tenths of an inch north of Chicago.
The Midwest as a whole has seen the drought expand slightly over the past week. The area now in a moderate drought has bumped up to near 19% after an increase of just under 1% compared to a week ago. The area in a severe drought has more than doubled in that time and now stands at just over 2%.
The drought woes out west continue. Some categories of drought have decreased a bit while others have increased slightly over the past week. Over 66% of the west is in a severe drought which is a drop of about 1%. The area in an extreme drought has diminished by just .16%. That is offset by increases in both the moderate and exceptional drought areas. Those categories have increase by around 1%. The drought outlook calls for the drought to persist or expand in much of the west through this summer.
Summer Seems To Be Starting Early
Meteorological summer starts on June 1st but it felt just like July on Thursday. O'Hare had a high of 86°. That was the hottest day since early September last year.
Highs today should again reach well into the 80s. The average high for today's date is 72°.
Summery 80s should stick around through at least Tuesday. That would be the longest stretch of 80s in more than eight months. Highs by Wednesday will slip back into the 70s for most of us. We will cool down by the middle of next week but still stay a bit above average for late May.
The temperature anomaly forecast for Saturday shows afternoon temperatures in and around Chicago about 10° to 15° above average. That means highs tomorrow at least in the middle 80s.
It stays steamy on Sunday too with the GFS model suggesting highs in the middle to upper 80s. A backdoor cold front will probably sag south across the area late in the day. The NAM model shows a pool of cooler air across southeastern Wisconsin and over southern Lake Michigan around 4 pm Sunday.
By 7 pm in the evening Sunday that cooler air comes crashing in and temperatures tumble into the 50s north of the city with cooler air settling south into Chicago too.
Staying Above Average Into June?
The last five days of May and first three of June are still favored to have above average temperatures overall. The even longer range subseasonal forecast (discussed below) seems to be at odds with this forecast as it indicates a slight cooling trend into the beginning of June at least compared to what we will see through this weekend. I will update that outlook on Monday. The 6-10 day forecast favors us for above average temperatures overall from May 26th through May 30th with Chicago's probability falling to between 30-40%. The 8-14 day temperature probability forecast keeps us above average overall from May 28th through June 3rd with those probabilities up slightly. Average highs for this period are in the lower to middle 70s.
The even longer range Subseasonal Experiment (SubX) temperature anomaly forecast is favoring the Chicago area for a slightly cooler than average last few days of May and first few days of June overall. The average highs for this period are in the middle to upper 70s. The temperature anomaly forecast for the week ending June 4th has us outlooked to be just a smidge below average overall. The forecast for the following week ending on June 11th has Chicago about average overall.
Long Rage Precipitation Probabilities Favorable
The longer range precipitation probability forecasts still favor us for above average rainfall overall for the end of the month and first few days of June. We'll have to wait and see if this will translate into some real rain that puts a dent in the drought. The latest 6-10 day forecast has Chicago outlooked for above average precipitation from May 26th through May 30th. The longer range 8-14 day forecast also has us favored for above average precipitation overall from May 28th through June 3rd.
Here is my 7 day forecast:
Today: Sun & cloud mix, warm & breezy High: 86
Saturday: Partly to mostly cloudy, spotty shower possible Low: 68 High: 86
Sunday: Partly to mostly sunny, pm sct. shower/t-storm possible Low: 69 High: 88
Monday: Partly to mostly cloudy, sct. shower/t-storm possible Low: 62 High: 85
Tuesday: Partly to mostly sunny, sct. shower/t-storm possible Low: 69 High: 84 (cooler lakeside)
Wednesday: Cloud & sun mix, sct. shower/t-storm possible Low: 63 High: 78 (cooler lakeside)
Thursday: Partly to mostly sunny, sct. shower/t-storm possible Low: 58 High: 74