More May Rain, Hopefully no "May"hem
This Monday evening I am watching several showers and thundershowers on the HD Doppler Radar scope. The word shower not storm after the word thunder is an important distinction to be made.
A thunderSHOWER by definition is a short lived (30 minutes or less) event where cells form in the heat of day, rain themselves out quickly often times followed by rainbows. That's Whitney Bayes' rainbow shot from Briarwood Drive in Catlettsburg Ky taken Monday evening. Breathtaking!
On the other side of the weather spectrum is the thunderSTORM which has more intensity (often inch per hour rate of rainfall), more staying power (can last an hour or longer) and a better arsenal of weapons (Hail, Wind, Downpours) at its disposal.
Naturally then the thundershower is not likely to produce any severe weather or flooding (though it only takes a single lightning bolt to spark a fire or hit a lazy golfer on the links.)
Overnight will will make the transition from a shower to storm pattern as a slow moving fall-like cold front arrives from the Midwest.
So by Tuesday morning as the polls open for primary day in WV, showers and heavier downpours in thunderstorms will be common. Given the wetness stored in the ground from April-May rains, some localized high water would be possible.
Here at 11pm, my colleagues at the NWS have their eyes on Vinton, Athens and Jackson Counties Ohio for possible high water. A Flash Flood Watch is in effect for this region until 8 AM.
Still, we have enjoyed two bright and breezy days now and the ground has dried considerably. That means it will take an inch or more of rain water to ensue new flooding. Most areas are unlikely to get enough rain to sponsor new flooding.
Instead, half inch to three quarters of an inch of rain will likely fall in spots on Tuesday especially in the morning. This would back up some storm sewers and lead to nuisance street flooding in poor drainage areas. In the process, small streams would show a rise but only to half bank full levels.
Our rivers too have started down after the weekend crest moved past and will remain near seasonally high spring levels until a mid week rise occurs. Since heavy rains are likely to fall from Parkersburg north to Pittsburgh, the mighty Ohio will show a strong rise Wednesday-Thursday. With any luck the rivers will clear and settle to good boating levels by the Mother’s Day weekend.
So to recap, some localized high water is possible overnight as new rains arrive in downpour form. No surprise since May is often the wettest month of the year.
Look for skies to brighten from west to east as the rains exit on Tuesday afternoon. So if you live in "West Virginia" and won't vote because of the rain, then "By God" plan your trip to the polls for the afternoon. Polls open at 6:30 AM and close at 7:30 PM. I expect several hours of dry weather in the afternoon and evening!