Memorial Day weekend is upon us. The tradition of honoring the men and woman who have served our nation will continue but without the parades and gatherings we are used to. Life in America has changed dramatically since the arrival of Covid 19.
One thing that remains the same is that Memorial Day is the unofficial start of summer. Most years the weather has that feel with average highs in my area ranging from 75 north to 79 degrees from north to south. After a week of cool temperatures I'm happy to say we'll see a quick transition to summery conditions this holiday weekend with our first bout of warm muggy weather, especially Sunday and Monday.
There are 3 key ingredients to our holiday weekend.
1. The breakdown of the rex block over the southeast
2. The northward advance of a warm-front Saturday
3. Increased moisture resulting in muggy conditions and scattered thunderstorms.
Thursday little change was observed around the central Midwest as the blocked upper air circulation over the southeast remained nearly stationary for the 4th consecutive day. Most areas again saw little if any sunshine and highs were 10-15 degrees below normal. These are the overall departures for the past 5 days.
This is the month to date. So far May has been cool and wet but a change is coming.
This is Thursday's late day GOES 16 satellite image showing the clouds that have persisted all week. The circulation center responsible for them is stationary over SC Kentucky.
Slightly better conditions are anticipated Friday but the real changes get underway Friday night and Saturday when the block breaks and we get into return flow and southerly winds. This is what the EURO meteograms are showing for temperature trends the next 10 days in Cedar Rapids and the Quad Cities. Notice there's a 6 day stretch where highs are at 80 or above. Night-time lows also remain in the mid 60s which will be good for the corn crop!
The Quad Cities
With the arrival of the warm front that kick starts summer, showers and thunderstorms are anticipated Friday night and parts of Saturday (especially the morning). As the warm front advances north it takes the rain with it Saturday night and Sunday. As forcing returns renewed thunderstorms are likely late Sunday night and Memorial Day. As for severe weather, the threat seems low. The best CAPE (Instability) is Sunday but there is nothing to kick off storms. Prospects do get better Monday with the approach of a front but the overall CAPE is displaced and greatest in central Illinois. More than anything else, locally heavy downpours in spots seems to be the greatest concern right now. We will keep an eye on the potential going forward.
As I showed you in the meteograms, much of next week the central Midwest is located in the firing zone on the edge of the westerlies, yet still in the warm moist air ripe for additional thunderstorms. It could be an active period with locally heavy rain if training becomes a factor in the nearly stationary set-up aloft.
Here in Maine we went over 70 for the first time since I've been here (just under 2 weeks). Tomorrow we're aiming for 80 as the sea breeze has temporarily turned off shore. Everything around here is predicated on wind flow. The north Atlantic is cold and when the wind comes directly off the ocean you can really feel the chill. Much like Chicago with a spring lake breeze only magnified! Have a great holiday and here's to the men and woman who have sacrificed to serve this amazing country. God Bless you all. Roll weather...TS