Rounds Of Storms Means A High Risk For Flooding
A broad trough of low pressure is developing over the Ohio Valley on this Monday in the wake of what was a great weekend across much of the area. We had a trough over us last week but the trajectory of heaviest rain ended up east of the Appalachians given where the trough was centered. The one today is much further west, which allows the moisture to pool over us rather than to our east. As a result, as we have already seen today, torrential rain will be common and can quickly result in high water.
With a strong high pressure system in the Atlantic (called a Bermuda High) retrograding westward toward the coast, it's setting up a "blocking" pattern whereby little can change. As a result, that trough will stay where it is until at least Thursday and possibly Friday, which means a daily risk for showers/storms, some of which can produce large hail and gusty winds and many of which will produce heavy rain. With multiple rounds of downpours we're concerned about the possibility of flash flooding...localized at first but perhaps becoming more widespread later in the week as the ground becomes even more saturated. If you live along a stream or creek you'll want to monitor the forecast closely and be prepared to seek higher ground if need be. In addition, it's a good time for anyone to review the driving tips for high water listed above.
A general 1 to 3" of rain is likely across the area, but some locations will end up with between 3-6" or even more (some spots already saw up to 3" today). Where these heavier bands of rain develop will be where the more serious flooding transpires and that's impossible to pinpoint at this stage. It appears central and eastern WV would be the more likely areas at this point, so I-77 eastward should be especially vigilant, especially given what happened today.
That trough will finally weaken and open up a bit by the weekend. The air won't dry out the way it did this past weekend but I do expect the storm coverage to drop considerably, with many more dry hours by Saturday and Sunday and warmer temperatures as a result.