Sunday forecast trends colder; wet snow possible in Md., West Va. mountains GFS model indicates temperatures only in the 40s in Washington, D.C. at 2 p.m. SundayReady for a shock to the system? The temperature Sunday afternoon may be nearly 40 degrees colder than this afternoon (Friday) in Washington, D.C. Some of the latest model guidance suggests temperatures will have a difficult time getting out of the 40s Sunday, with temperatures in the mid-40s during the afternoon, along with rain. GFS model is forecasting a high of 53 degrees Sunday in Washington, D.C., which may be generous.The National Weather Service in Sterling writes (bold text indicates my added emphasis): Recall a few days ago we talked about the GFS model simulating snow in Washington, D.C. Sunday. Well, it may not be that far off. You may only need to drive about 2-3 hours to encounter the white stuff. High elevations in the the Laurel Highlands in southern Pennsylvania as well as the mountains of western Maryland (Garrett county) may see wet snow or mixed rain and snow, writes the NWS office in Pittsburgh: Snow is probably most likely in some of the higher peaks of West Virginia, around Snowshoe, for example. Says the NWS office in Charleston: While snow is exceptionally rare in D.C. in early October, it's fairly common along West Virginia's highest ridges, above 3 to 4 thousand feet. As the NWS office Charleston reminds us: