UPDATE 9:50 AM: The weak wedge is a little slow in developing today, so with more sunshine, we may get well into the 60s. END UPDATE
Moisture has not been abundant in recent weeks, but it will be a little bit damp, maybe even briefly wet, over the next couple of days. The first trigger is a weak cold front that will slip southward and stall over our region on Sunday. Some easterly winds flow along this front will bank moisture against the mountains for a “wedge” effect, with clouds, fog and perhaps some light rain or drizzle. Temperatures will start out above normal lows that run in the mid 20s to low 30s — we’ll be in the 40s, mostly, some upper 30s — but may have trouble rising past 60 with this wedge present. By Monday , a low-pressure system tracking out of the Northern Plains and across the Great Lakes will sweep moisture northeastward from the Gulf of Mexico along a cold front. The southwest flow ahead of this low will not only thicken our moisture, but push out the stalled front and wedge, and lead to almost as much warmth as last Monday, with 70 degrees possible in Roanoke and locations to the south and east. We will probably see some fairly widespread showers — maybe even a few rumbles of thunder, with a strong thunderstorm wind gust or two not out of the question — Monday afternoon and evening. It appears, however, as if the richest moisture will slide just to our west, into the Ohio Valley and along the western slopes of the Appalachians, but some 0.25 to 0.75 rainfall amounts may occur in most of Southwest Virginia. Certainly not a drought breaker, but at least a little wetness for a region in growing and intensifying states of dryness. This cold front will have some Arctic punch, but the windy cold behind it will only carry us back to near normal for early December — mid 20s to low 30s lows, mid 40s to low 50s highs — for a few days before the next mild trend ahead of the next developing storm system in the central U.S. Higher elevations may see a few snowflakes early Tuesday, but this doesn’t look to be a substantial upslope snow shower event.
The early week storm looks to be the first of maybe 3 or 4 (or even more) similar storms in the next 2-3 weeks (or more) as punches of Arctic air collide with the mild Pacific-influenced air covering much of the nation. Unfortunately for Southwest Virginia snow lovers, the main wintry effects will be focused on the central U.S., as they are tonight with blizzard conditions in the Dakotas. It’s a volatile pattern setting up nationally, the results of which may set up our weather pattern for the heart of the winter season after Christmas and into early 2013. I still think we end up cold by late month and/or early January, but much is unsettled.