KEEPING IT COOL
Wednesday was the second straight morning that some outlying areas dipped into the 40s. What a feeling out the door with the coolest lows recorded at Tipton (47°) and Crawfordsville 46°. The low early in Indianapolis of 58° was 5-degrees warmer than Tuesday. The lack of humidity is behind the cooler temperatures. With less water content, dry air cools quickly at night, and we are expecting another comfortable morning Thursday.
The air has its origins from Michigan, where early morning lows fell into the middle 30s. Some wildly low numbers included 34° at Grayling and 35° at Cadillac!
The return flow around high pressure that sits to our southeast will add an increased wind from the south tonight, preventing the lows from reaching the 40s. Early morning Thursday will open mainly in the 50s, still a treat for this time of the year.
The tropical air is set to return in a big way starting Thursday night. The south winds will carry warmer air into the state Thursday afternoon, then the dew point will surge entering Friday morning. The thick, heavy air with origins from the Gulf Coast will be reluctant to go for several days.
The key to humidity is the dew point. The dew point is the true measure of moisture in the air, and when below 60°, it is comfortable. When that number rises, it becomes more and more uncomfortable. We are forecasting a dew point into the mid 70s by Friday afternoon and possibly remaining near 70-degrees for much of the upcoming week. The highly humid air will not allow nighttime temperatures to cool, so enjoy this mild spell. It is about to get stuffy, or what I like to call “MUGGLY.”
After we turn humid, the threat for a daily downpour really increases. While no organized storm system or fronts will be present, an unstable and unsettled pattern is to take hold yielding a daily threat of showers and thunderstorms. As we fine tune the forecast, the likelihood of an “all day rain” is quite small, but we are fine tuning as to which of the days may be more soggy than others.
The jump in humidity late Thursday could bring on some storms as early as Thursday night with perhaps the wettest or the most coverage of rainfall coming on Friday. Check back as to updated timing and intensity of the rain and storms. At this time, the prospects of severe storms is limited but with so much tropical air, locally heavy rainfall totals could be in the works.
Below is a side-by-side comparison of rainfall totals ending 8 p.m. Friday. You will notice there is a large spread in the rainfall amounts and still plenty to be resolved on the location and intensity of the rain. The takeaway is that locally heavy rain is a strong likelihood. I do lean toward the lighter totals for now, and we will keep you up to-date.
Be sure to check back!