An upper level low will along the Southeast and Mid-Atlantic coast for several days next week. High pressure building across the north will push the heaviest rain to the south. The mountains and South Central Virginia area has the highest chance at seeing moderate to heavy rainfall throughout the week, due to a northeast-east wind flow, causing rain to develop.
New model data continues to be split, with the European model further south, and the GFS (American) model to the north and along the coast. The position of the low and where it drifts over the next several days next week, will determine who will see the heaviest rain.
The latest European Ensemble mean has measurable rain reaching as far north as the Mason-Dixon Line. At times, some models have tried to develop another area of low pressure, suggesting some type of tropical-characteristics, which would mean a flood threat across portions of North Carolina, especially along the coast. However, the chance of anything developing into a tropical system seems to be very low at this time. With a east or northeast wind flow from high pressure, and east wind off the water from the upper level low, it still appears that North Carolina and the mountains would be the “bullseye” for the potential at seeing significant rainfall.
Our forecast is using a blend of models and ensembles, but also adding the east/northeast wind flow against the mountains, which suggests where we’ll see the heaviest rain. I do not think that there will be a flash flood risk at this time, however, there will likely be streams and creeks that overflow and we’ll see the Dan, New, and James Rivers rise by late next week. This forecast could change over the next few days and is highly dependent on the strength of the high and position of the upper level low.