In the very big picture, the weather pattern is still fairly similar to what we’ve seen the last couple of weeks, with high pressure and warmer than normal temperatures along the West Coast. That is actually being pumped up even more by this powerhouse northern Pacific storm moving into Alaska– by pumped up, I mean the strong counterclockwise rotating around the low is lifting warm air even farther north into western Canada. But the downstream troughing, or jet stream winds dipping to the south on the east side of the clockwise circulating high, has flattened out quite a bit in the Eastern U.S. In fact, upper-level winds have largely become “zonal,” or west-to-east, across the southern half of the central and eastern U.S. The result is that cold fronts driven south by the high to the west are hanging up in the west-to-east flow, and only grudgingly moving south. As you can see by the progress of the Hydrometeorological Prediction Center maps for Thursday, Friday and Saturday, the projected rain totals only gradually shift southward, and wash out quite a bit by the weekend as a stronger storm system develops in Texas. For Southwest Virginia, this means there will be a chance of showers and some thunderstorms each day through at least Sunday, but not a particularly large chance any particular day. Friday, for now, appears to hold the best chance of rain. High temperatures will again be muggy — mid 70s to low 80s, mostly — on Thursday before gradually pulling back into the weekend. The cold front will likely get enough of a push to clear out by early next week, bringing drier weather and temperatures to near the 70s highs/upper 40-low 50s norms for a few days.
When you see big storm systems like the one approaching Alaska, there is usually a downstream ripple effect in the future that will affect us. We may see a strong cold frontal passage toward the end of next week.