IT'S GOOD TO SHARE...
In the world of weather, all things are not created equal. Seasonal weather patterns often set up in such a way that individual storm tracks mirror one another. Some places are continually in the line of fire while others can barely scare up a raindrop or a snowflake. That's been the story in my area this summer. Rain has been plentiful in the SE while the NW has struggled to get rain with any regularity.
Take Cedar Rapids for example, today will be the 20th consecutive day with no measurable rain. Going back to July 1st, just 5 days have seen more than a trace of rain and the deficit over that period is close to 4 inches. For perspective, we figure most areas average around 1.25" per week during this time of the year.
On the other side of the coin, Washington, Iowa just 50 miles south of Cedar Rapids picked up 5.23 inches of rain during the same period. That's about 4.5 inches more than Cedar Rapids. Washington also had 11 days with measurable precipitation compared to 5 days in Cedar Rapids. If that's not enough, Washington had 3 individual days where rainfall was more in a single day than Cedar Rapids had for the entire month! What we have here is an inability to share.
Going back 6 months you can see the sharp cut-off from below normal amounts by up to 11 inches in my NW counties, to above normal totals by as much as 10 inches in my SE counties. Over a span of 100 miles rain totals vary by as much as 21 inches.
Within my area, here are some of the precipitation and temperature departures for July as compiled by the NWS in the Quad Cities. Notice monthly temperatures were coolest over the southeast where precipitation and cloud cover was most prevalent.
By the way, these are the temperature departures for the past 5 days. This was something the MJO tipped me off to more than 10 days ago, well before the operational models ever saw the cool air coming.
Knowing that many areas could use a good rain, (especially my NW counties) I'm looking for promising signs. I do see the threat for scattered storms Thursday night and Friday and again towards Saturday night and Sunday. However, there are limiting factors in each scenario regarding coverage or amounts. To be honest, I have low confidence in any particular model and at least with the first system Thursday night, dry air could be an issue and I'm leaning towards the lighter rainfall solution depicted by the GFS. If the EURO is correct, rain chances improve Sunday with increased moisture and forcing. Hopefully models will show a more unified depiction in coming runs.
One thing I am confident about is the fact that temperatures and humidity are going to spike again this weekend and much of next week. We are soon to leave the cool grip of the MJO phase 8 we are in and transition into an amplified phase 1. As you can see in the temperature analog on the right, phase 1 has a strong correlation towards above normal readings during the month of August.
Assuming current trends hold. I could see several days next week with highs of 90 or above. Even worse, dew points are shown in the 70s which is going to send heat index values to 100 degrees or higher. While a few diurnal storms are possible in such a tropical environment, the spawning grounds for nocturnal thunderstorm complexes which are notoriously larger and better rainfall producers are uncertain at this distance. Plenty of time to figure that out.
As for Wednesday, it looks like another glorious day with light winds, hazy sunshine, limited humidity, and highs in the low 80s. That's a keeper. Roll weather...TS