Periods of heavy rainfall with the remnants of Barry may lead to flash flooding on Wednesday. Temperatures and high humidity Friday through the weekend will create dangerous heat index values in the 100° range or higher are likely Friday, Saturday, and Sunday afternoon.
As we’ve been discussing here for the last week or so, there are some weather hazards about to impact the Valley over the next several days. The expected warm front has moved through on schedule and this we can already feel the difference in humidity. Dew points across the Valley are now in the upper 60s to around 70° making for some very muggy conditions.
Temperatures this afternoon will peak in the upper 80s. That coupled with the higher moisture content will lead to a somewhat unstable airmass this afternoon. We can expect scattered showers and thunderstorms to develop as temperatures warm up this afternoon and continue into the evening.
The more humid air means there is more moisture in the air so any storm will have the potential to bring briefly heavy rain. They should move along quickly, though, so any flooding issues will be minor.
The potential for flooding will increase tomorrow as they remnants of Barry move into east-central Ohio. Everyone will get into some rain and thunderstorms as this moves through. The threat for severe thunderstorms is low, but we do have a slight risk of flash flooding in place.
Fortunately, we’ve been dry lately and we’re not in the same fix as we were a week ago when heavy rain left the area saturated. Our tolerance for heavy rain from Barry has improved and this will be a big help when the rain arrives tomorrow.
Tropical downpours will be possible at times tomorrow and there may be issues with street flooding as well as backyard flooding. But the threat for widespread flooding is not much of an issue. The rain from Barry won’t go on for days. It will move through quickly and rain should taper off Wednesday night – early Thursday morning at the latest.
Rainfall totals will vary over the area but generally speaking, the models have been fairly consistent keeping the total rainfall at around an inch – give or take a little. This morning’s NWS outlook pegs our area with around 8/10ths. Some neighborhoods will see more – some will see less.
After the remnants of Barry move through we will need to focus our attention on the hot and very humid weather that will head our way for the weekend. An upper-level ridge will shift east to bring the hottest temperatures of the summer and by Friday we’ll be looking at afternoon temperatures in the low 90s. With tropical dew points in the low to mid 70s, heat index values will reach the 100° area – maybe even a few degrees higher.
Friday will likely be the hottest day but it will remain hot, humid and miserable Saturday and Sunday as well. Those who must be outdoors Friday and through the weekend will be at risk for heat illness. Take appropriate precautions if you must be outdoors. Folks without air conditioning will also be at risk. Temperatures will only drop off to the mid-70s at night, so there will be little relief from the heat.
The good news is that it will not be this hot for an extended period. Temperatures will cool to the upper 80s by Monday and return to near average. By Tuesday we may even see below-average temperatures.
Monday will start out humid, but dew points will decrease through the day behind a cold front. Much drier air will return to the Valley for Tuesday.
With such a drastic change showing up in the modeling, I would expect it to be accompanied by showers and thunderstorms and possibly some severe storms to boot.