Dry pattern holds as meteorological summer kicks off

Historically Dry May:

Even though we picked up a little bit of  rain overnight, it didn't add up to much - just 0.05". That brings our total rainfall for the month of May to only 0.52", officially making it the 2nd driest May on record. A stark turn around from the wet start to spring, and a clear sign of just how dry conditions have been across northern Illinois.  

Meteorological Summer: 

June 1st marks the official start of the hurricane season in the Atlantic Ocean - but closer to home, it kicks off meteorological summer. This is the time of year when our average temperatures begin to peak, with normal highs climbing into the low 80s across northern Illinois. It's the beginning of our warmest stretch of the year, where longer days and stronger sun really start to take hold.  

Remaining Dry:

High pressure remains firmly in place, which means rain chances will stay limited. The tradeoff, though, is a pleasant stretch of weather - expect plenty of dry time today, Tuesday, and Wednesday with highs holding steady in the low 80s, right in line with early summer comfort. As we get closer to the weekend, there are some early signs of that rain chances may tick slightly higher, but for now, meaningful rainfall still looks hard to come by. 

High and dry early this week, increasing humidity by weekend

 [6:20PM] While most of the area will be dry this evening, a few very isolated sprinkles may be able to work through some drier air through the night. The rainfall will not amount to much. Only a few hundredths of an inch may come down for those who do see any rain.

Pending we don't see any measurable rainfall before midnight, this May will go down as the driest on record for Rockford. Only 0.47" of rain fell this entire month at the airport, compared to the average 4.18" rainfall we typically see in May. Especially remarkable given how long ago some of the other top 5 have been!

A tiny bit of moisture may produce few sprinkles from time to time from late evening through the overnight hours, but most of the area will remain dry at any given time. Whatever rain does fall probably will not amount to much, likely less than a tenth of an inch for those who do see rain.

Another round of dry high pressure will then take hold early in the week, bringing pleasant afternoons and cooler nights. Monday and Tuesday night could feature lows nearing the upper 40s in a few locations!

But the lack of humidity will not last for long. As that area of high pressure slides away, surface winds will turn to come from the Southwest. That will bring an increase in moisture, especially at the surface. Dew points will likely climb into the 60s by Friday evening. A more unsettled pattern will develop as a result, with at least isolated chances for some showers and storms beginning Thursday night. While it may not be a soaking rainfall for everyone, prospects for much-needed rainfall look a little better through the first week and half of June.

Subtle pattern change may bring slim rain chances late next week

 While we have been stuck in the warm and dry pattern lately, subtle changes may be on the horizon. The large scale upper level ridge has been a dominant feature for our weather pattern, bringing surface high pressure systems, a dry Easterly wind, and very little rainfall over the last week or two.

That ridge will begin to break down late into the week, resulting in at least a few slim chances for rain starting Friday. Increased jet stream flow overhead will result in increased moisture and subtle waves that are able to precipitate some of that moisture out as rain.

Unfortunately, it probably won't be the widespread and soaking rain that we need, but anything helps at this point. Coverage of rainfall may not reach much higher than 30-40% at any time Thursday night through the weekend, but at least some locations in the Stateline will have a shot at some rainfall, though others may end up staying dry. It's not much, but it's a start!

Warm and dry, but pleasant this weekend

 It feels like a broken record saying this, but we have more of the warm and dry pattern to come. At least for the weekend that means pleasantly warm days and cooler nights! Afternoon highs will push near or above 80 degrees both Saturday and Sunday with overnight lows in the low/mid 50s.

The one feature of note this weekend will be a lake-enhanced backdoor cold front pushing in off Lake Michigan. This will bring stronger winds from the East during the day gusting near 25 mph at times. Another impact that front will have is the substantially cooler evening, especially for Eastern parts of the Stateline. Temperatures will quickly fall back into the 50s, so any outdoor plans you have may start turning a little cool by 7-9PM.

"Rapid Onset Drought" possible as dry conditions continue across the Stateline

 Written By: First Warn Weather Intern Patrick Murray

The Climate Prediction Center has highlighted the entire Stateline region under a risk for what they're calling a "Rapid Onset Drought". A rapid onset drought (also called a "flash drought") happens when abnormally low precipitation amounts are coupled with abnormally high temperatures.

Typically, we don't see our first 90 degree day until June 4th. The past month has included many days with above normal temperatures. This year, we saw our first 90 degree day on May 27th, a full week early.

This is all thanks to high pressure which has been sitting over the Great Lakes region for the past few days. This area of high pressure will slowly shift east as an overall pattern change takes shape, but this likely won't happen until well into the next week.

The current drought monitor from the CPC (valid as of Tuesday) highlights almost the entire Stateline region under the "abnormally dry" category. While we aren't technically in a drought as of now, we will likely see one develop over the course of the next week or so.

Our next decent chance for rain doesn't appear in the forecast until Friday (6/5). There is a slight chance for an isolated shower or thunderstorm on Monday (6/1) and Thursday night (6/4), but overall, we look to stay very dry.

Warm and dry weather causes abnormally dry conditions to expand in northern Illinois

 

It should come as no surprise that the abnormally dry conditions have expanded across northern Illinois and southern Wisconsin following a very warm and dry stretch of weather. The latest drought monitor from the National Drought Mitigation Center shows the drier than normal conditions expanding from where they were just last week, to now covering the majority of northern Illinois and southern Wisconsin.

This follows what has been an exceptionally dry May with only 0.47 inches of precipitation being recorded at the Rockford Airport. Month to date the May precipitation is 3.25 inches BELOW where it should be. And with only a few days left of the month our chances for precipitation look to remain very low! Month to date we are the driest on record, and this month will likely be the driest May on record since record keeping began in 1905.

The pattern may start to change after the first week, to week and a half of June as the blocking ridge that has been in place starts to break down. This may allow a few more storm systems to move through giving us at least a little better chance for some precipitation. Although, our warmth looks to be sticking around.

Temperatures hit 90 degrees for the first time this season Wednesday afternoon

 

Phew! It was a toasty one this afternoon with temperatures warming into the upper 80s and low 90s. Rockford reached its warmest temperature so far this season with a high of 91 degrees! The record high for May 27th is 99, which was set back in 2012. The low this morning fell to 52.

Skies have been mostly sunny for much of the afternoon with only a few cumulus clouds bubbling up over the last few hours. Those clouds have formed with the little instability we have overhead but are beginning to quickly fade this evening. Temperatures will remain in the 80s through sunset but are expected to quickly drop following the passage of a back-door cold front this evening. Overnight lows will once again drop into the low to mid 50s.

Thunderstorms have developed along the cold front to our north in Wisconsin but will really lose steam as they travel closer to southern Wisconsin after 7pm/8pm. There is a small chance for an isolated shower or storm in southern Wisconsin, but the vast majority of the viewing area is expected to remain dry.

On average, our first 90 degree day is usually reached around June 4th. Last year the mercury reached 90 degrees on May 15th. Our earliest recorded 90 degree day occurred on April 10th back in 1930, and our latest was in 2008 when we didn't reach 90 degrees until September 1st. This will likely be our only 90 degree day through the rest of May as temperatures are expected to remain in the 70s and 80s through the weekend and into the beginning of June.