A REFRESHING CHANGE...
As expected, a cold front rammed its way through the heat and humidity of the past few days Wednesday evening. It was the spark for scattered thunderstorms and a tornado watch was issued for the north and later a thunderstorm watch was posted for the south. While a few warnings were issued, severe weather was minimal. Rainfall, was spotty too with some localized heavy amounts (1 inch+) in downpours while others missed the rains altogether. Such is the nature of summertime thunderstorms.
The hi-res satellite from Wednesday evening shows the arching band of clouds associated with the cold front.
Late night Wednesday 182 reports of severe had been issued by SPC, most were wind related. At least 25 of the 182 total occurred outside of the Midwest, primarily in Alabama.
With the front south of the region Thursday we begin a trend that sees cooler temperatures and lower humidity through the coming weekend. Models are more aggressive with this trend than just 12 hours ago. Look what the GFS is now showing for temperatures Thursday through next Tuesday (June 21st). Highs Thursday are back in the low 80s and 70s are projected Friday through Sunday. Wow, quite a change for the mid 90s of the past 2 days!
Notice too the steady drop in dew points which reflects a big reduction in humidity. We go from 73 Wednesday to 64 Friday and 46 by Sunday morning! That is good stuff.
Notice by Sunday readings are projected to be 5-10 degrees below normal. A striking reversal from the positive departures of the past few days.
You can see at the surface this coming Saturday the 1028mb high situated over Lake Superior that drives the pleasantly cool air into the region on N/NE winds. It's what we call a back door cool front due to the fact the fresh air arrives from the northeast as opposed to the west.
With time, the surface high breaks down and travels east allowing southerly winds and another heat dome to build back into the central U.S. early next week. 90s are back on the table and with southerly winds, moisture and humidity will increase Monday and Tuesday as well. There are major differences in the intensity of the heat with the EURO at full sizzle this coming Tuesday depicting highs around 100 from I-80 south. The GFS is kinder keeping highs 5-10 degrees cooler. No matter what the intensity of the warmth turns out to be, most models are now of the opinion that another cold front will quickly snip the heat off Tuesday night or Wednesday sending readings to more seasonal levels. That's probably the next best chance for any meaningful rain in the next 6-7 days.
Turning to the topic of rain, the 16 day rainfall departures are worth noting. With ridging centered over the mid-Mississippi Valley, the ring of fire is situated to the north bringing healthy rains to the upper Midwest while we stay high and dry further south.
The 8-14 day precipitation outlook from CPC is not as dire with my area closer to normal. That is a possibility if the ridge is not as stout as most models suggest allowing the heavier rains to sink further south clipping my area. As for temperatures, there is a decided trend for above normal readings in the long range after we enjoy our weekend reprieve.
One thing there's no disputing is the fact the last 4 days have been toasty with average highs running 5-14 degrees above normal over the central Midwest, Below you can see the average temperature departures June 12th through the 15th...a very warm period in what's otherwise been a cool spring.
Time for us to temporarily dial back the heat and we will, especially Friday through Sunday. That's all I've got for now. Have a solid day and roll weather...TS
