Meteorological Summer, the official start of summer, is Friday, June 1st and after the warmest Memorial Day Weekend on record in the Cincinnati area, regional temperatures are cooling and may be relatively chilly to kick off the new season as a rather large weather pattern change takes place across the United States.
The change will start with a strong low pressure system developing in the central Plains tonight and tomorrow, then moving toward Louisville tomorrow night and into Michigan on Friday. In advance of the storm, a large high pressure area (sinking air, fair skies, light winds) is pushing colder air south from Canada into the northern Plains and Upper Midwest where lows were in the 30s and 40s with areas of frost Wednesday morning. Cooler air will move all the way into the Cincinnati area by Thursday morning with lows in the 40s to low 50s and highs only in the low to mid 70s on Thursday…a welcome change from the 90s last weekend.
The approaching storm will try to bring warmer air (unsuccessfully) back into our area Thursday night and Friday and that clash of air masses will lead to showers and thunderstorms, some heavy and possibly strong…mainly south of the Ohio River. Not only will the advancing warmth be squashed, but we’ll actually be cooler on Friday as we kick off summer, with highs in the mid to upper 60s! One computer model forecast keeps us in the low 60s. In case you’re interested, the coldest high temperature ever on June 1st was 57 degrees from 1889. We won’t be threatening records, but we won’t be feeling like summer either.
I mentioned a large weather pattern change at the start of this article but a single storm and a brief shot of cooler air this weekend certainly doesn’t represent an overall pattern change. However, the next few days are just the start of what may be a setup not seen in years.
Beyond this weekend I expect a large low pressure area (rising air, clouds, precipitation, and stronger winds) in the upper atmosphere to develop and maintain itself over the eastern United States and the western Atlantic Ocean for the first 10 days of June and possibly through the middle of next month. At the same time a second large low pressure area is expected over the western United States and eastern Pacific Ocean with an area of high pressure sandwiched between the two lows. That is what meteorologists call a “highly amplified” weather pattern, and this specific setup is called an “Omega Block” (note the graphic with this article).
If the computer models are correct, we can expect rounds of cooler air from this Friday through the first two weeks of June. Most days will be in the 70s with a few days reaching the 80s…but almost no threat for a 90-degree high until late in the month, if at all. After a mild winter and warm spring, I have been calling for a cooler summer (since late last year) and we’re certainly seeing indications of one of the cooler summers in the past 25 years.
Keep your eyes on the sky and enjoy the changing weather…
Skyeye Weather LLC