- May 20, 2021

WARMER DAYS ARE HERE AGAIN...

Lo and behold, I saw the sun Wednesday and that was a reason to cheer. So too were the warmer temperatures. Thanks to that strong solar energy late May provides highs popped into the mid to upper 70s areawide. With dew points in the mid 60s the element of humidity came into play as well. Bottom line, it finally felt like summer was creeping in.

In fact, summer is the theme of the forecast into early next week as the pattern has turned ripe for another week of warm and rather muggy weather. You can see why that's the case by observing the Madden Julien Oscillation (MJO). Following the green lines you can witness it making the loop through phases 4, 5, and 6 between now and June 2nd.

If you look at the phase analogs for temperatures, you can see all 3 phases are warm in May, especially 4 and 6.

The MJO has been seeing this trend for well over a week and now it's well teleconnected with the ensembles and deterministic models so there is high confidence in the warmth.

The EURO shows a 10 day temperature departure that looks like this.

The upper air flow at 500mb shows the southwesterly draw that feeds the warmth.

This is also a pattern that is loaded with moisture. This next graphic shows the vast amount of water vapor covering the central U.S. Rest assured this will keep things on the muggy side from now until the middle of next week.

Warmth and humidity is usually a recipe for showers and thunderstorms, especially when there's a triggering mechanism. While there's nothing very organized weak disturbances within the southwest flow will trigger scattered showers and storms on a daily basis through early next week. Not everybody will experience these and there will be lots of dry hours even in the areas where they occur. What's difficult is timing these disturbances more than 2 days in advance. Just know that there are at least small chances through Monday. The next 2 days, the odds are highest early in the day and again later in the afternoon and evening. This is what the EURO depicts for total rain over the next 10 days. You can see the central U.S. is the focal point for rain.

I'll also mention with the high amounts of water vapor these generally low topped storms can dump out some good rains in a short amount of time. These should be isolated in nature. As we get into the weekend instability (CAPE) should grow higher and there is a chance a few stronger storms could develop. At this time, I don't see anything that looks widespread or particularly severe. That will be something to watch next week as we get a front and some forcing in closer proximity.

As we all know this year has been very quiet in the severe weather category. Only 3 severe thunderstorm or tornado warnings have been issued by the NWS in the Quad Cities. As low as that number is, 1993 at this point actually had less with only 1 such warning. 1986 also only had 3 at this point as well.

Looking at years as a whole and their final tallies of warnings, 1986 and 1993 went on to be quiet seasons (in the bottom 33 percent) with below normal activity. In fact, 1986 was a shut down year (the lowest on record) with only 21 warnings issued from the Quad City office. Most of those came in July and August well after the peak of the season. If things don't pick up in the next couple of weeks this year could end up being a bust as well. Obviously, that's not a bad thing!