AS THE WEATHER WORLD TURNS...
There's nothing monumental in the weather coming up but there certainly are some interesting things that will impact the Midwest in coming days, not the least of which is a turn toward summery temperatures in the long term. Before we get to that the forest fire season is off to an early start, especially in Canada. All the icons from British Columbia to Manitoba indicate fires greater than 1,000 acres. Alberta is the epicenter.
With current winds prevailing from the NW, the smoke has condensed and moved southeast into the Midwest. Were it not for the smoke on our skies, Wednesday would have been a crystal clear day with bright blue skies. You can see the milky nature of the smoke as it appeared on the GOES hi-res satellite imagery.
The smoke plume extends west to east from the Wyoming border to the eastern seaboard and north to south from Canada to St Louis. Pretty impressive, particularly for mid-May.
Fortunately, vertical mixing is not strong enough to get much of this to the surface so the smoke is elevated. However, some moderate to unhealthy levels of air quality have been measured in parts of central Iowa. The smoke may linger another day before wind trajectories are briefly altered.
The front that creates the change is tied to a vigorous upper air disturbance charging southeast out of Canada. Thursday night the closed circulation is situated over northern Minnesota.
As the energy digs into the Great Lakes it will sweep a notable cold front into the region Thursday night.
Ahead of the front Thursday temperatures warm with highs reaching into the upper 70s to low 80s. The southerly winds also bring enough moisture to establish the instability necessary for a broken line of showers and storms Thursday night. Models differ a bit on timing with the GFS about 6 hours faster than the EURO. That's not much but it does make a difference on the amount of instability available for somewhat stronger thunderstorms if the faster GFS prevails. That detail will need to be worked out Thursday morning. Right now, little if any severe weather is expected. Either way, the showers and storms arrive in the NW half Thursday night and exit the southeast half early Friday morning. With the best dynamics in play further north and the fast movement of the front, rainfall in general should be light...1/4" or less in most spots. Here's what models currently suggest.
The GFS
The EURO
The 3k NAM
The biggest impact of the front will be to bring much cooler readings back to the region Friday. Brisk NW winds could hold highs close to 60 in the far north with mid to upper 60s elsewhere. That's 15-20 degrees cooler than just 24 hours earlier.
With clearing skies and diminishing winds, temperatures by Saturday morning are likely to be in the low to mid 40s. The GFS is even more aggressive with a few spots in the north touching the upper 30s. I think the GFS is a few degrees too cold.
SWING INTO SUMMER AT ONE OF THE MOST UNIQUE ACCOMMODATIONS IN THE MIDWEST...
A GOOD LOOKING WEEKEND...
Following the chilly start Saturday morning, readings warm nicely with afternoon sunshine. Highs will head for the upper 60s north to low 70s south. Sunday is even better with low 70s north to mid 70s south...a near perfect day!
I still see no reason to stray from the idea the long range forecast looks favorable. Above normal temperatures should settle in next week meaning highs in the 70s and eventually 80s. Rainfall looks pretty meager too. The Climate Prediction Center is in line with my thinking showing both trends in the 6-10 day outlook valid May 23-27th.
Over the 10 day period May 22nd-June 1st the GFS indicates this for daily temperature departures.
Precipitation over the next 15 days is shown well below normal.
With that positive outlook, I can end this post on a good note. Have a fine day and roll weather...TS
