ALL FIRED UP...
One of the things we typically don't deal with in mid-May is smoke from wildfires. However, this year they are already raging in Canada and wind trajectories will be right for us to witness the smoke in our skies. Below you can see the milky appearance of the smoke on Tuesday evenings satellite as it moves southeast into my northern counties.
Vertical mixing along a southward moving cool front clearly defines the leading edge of the smoke plume as it approached the Illinois border in this animation Monday evening.
The bulk of the higher smoke concentrations are expected to be over my area Wednesday afternoon lingering into Thursday. The majority of the smoke remains aloft as vertical mixing remains weak. The primary impacts for us will be a milky looking sky and the potential for some brilliant sunsets. Below you can see the width of the plume is about as long as the state of Minnesota. The orange and yellow dots indicate where enough smoke has reached the surface for moderate to unhealthy breathing levels to our northwest.
Here's another image showing where PM 2.5 readings were a concern late Tuesdayy. Levels will be higher in my region Wednesday as the smoke advects southeast.
Lost in the smoke is a backdoor cool front that is plowing southeast. The main thrust of the cool air is aimed at the Great Lakes so the biggest cool-down will occur in my NE counties, especially in NW Illinois. Easterly winds despite milky sunshine will keep highs in the upper 60s there to the low to mid 70s elsewhere. Much of the region will be a good 10 degrees cooler Wednesday afternoon than 24 hours earlier. The dip will be enhanced by the cold water of Lake Michigan. Chicago will be down about 25 degrees!
Thursday temperatures get a nice bump up thanks to warm air advection ahead of our next disturbance, a vigorous upper air low that again digs towards the Great Lakes in the existing NW flow. SW winds will send temperatures into the upper 70s to low 80s and bring enough moisture to allow dew points to pool near 60 ahead of the advancing cold front. There should be enough CAPE (instability) to fire a broken line of storms on the front Thursday night. While a strong storm or two is possible the overall severe threat is low. The fast movement of the front should also keep rain totals light but some brief heavy downpours could occur in the stronger updrafts, especially in the north. Any lingering showers should depart the southeast early Friday morning. Here's what models are suggesting for amounts.
The GFS
The EURO
The NAM
The 3K NAM
As for Friday's temperatures, they take a pretty good hit behind the front with the far north struggling to get above 60 with a brisk NW wind. The south should reach the mid to upper 60s before readings fall in the afternoon. The roller coaster dips again with temperatures Friday afternoon 15-20 degrees cooler than 24 hours earlier.
Saturday morning has the potential to be quite cold with fair skies and light winds allowing significant radiational cooling. The GFS as it has for a couple days continues to advertise lows in the upper 30 in my far northern counties.
SWING INTO SUMMER AT ONE OF THE MOST UNIQUE ACCOMMODATIONS IN THE MIDWEST...
A LONG TERM WARMING TREND...
Fortunately, the chill fades quickly Saturday morning and the rest of the weekend looks sensational. Highs Saturday should be in the upper 60s to low 70s warming to the low to mid 70s Sunday. Sunshine and low humidity will prevail.
The long range continues to look very promising with warmer temperatures next week and below normal temperatures. CPC shows this for the 8-14 day period May 24-30th.
Now that's the way to end the month. Until next time, roll weather...TS
