An experimental version of the American model (GFS-FV3) shows light snow on Northern Virginia during the Sunday afternoon, mainly south of Washington. (TropicalTidBits.com) Every day this week we have highlighted how the Washington region was on the verge of a winter storm coming from the south on Sunday. Small shifts in his final position would, as said, make the difference between no snow, some snow and a lot of snow. Over the past 24 hours, the forecasts for the storm have made a small but logical shift to the south, reducing the chance of snow heaps in the Washington region. It is not yet a game over for snow, but fairly close. While on Wednesday we had 35 percent chance of at least an inch of snow in the region, we would reduce it by 20 percent today. And that may be generous. The chance of a few centimeters or more is a maximum of 10 percent or less. Areas in the north of the district can not even see flake (probability of 60 percent). Our southern suburbs probably have a 50 percent chance of seeing some light snow or gusts that could deposit a dust or so – especially late Sunday afternoon to Sunday evening. "The models have almost slammed the door with the possibility of a big blizzard," said Wes Junker of Capital Weather Gang in an e-mail. He explained that the northern branch of the jet stream is just too strong and does not allow the storm along the southern jetstream to reach far north. "There is still a small chance that we see light snow or gusts but even that chance fades," Junker said. A heavy blizzard for southwestern Virginia (average confidence) and western North Carolina (high self-esteem) remains in the cards, with more than one foot possible. But Washington can be lucky enough to see even a few flakes. Here is a summary of the model predictions for the Washington region, and it is a sad situation for snow-lovers: Operational American (GFS) model: No snow from the north of the district. Turbulent light snow or gusts possible in our southern suburbs Sunday afternoon and evening. Little or no accumulation. Experimental American model (GFS-FV3): no snow from the north of the district. Turbulent light snow or gusts possible in our southern suburbs Sunday afternoon and evening. Little or no accumulation. 48 hours ago this same model predicted 15 to 20 inches and 24 hours ago 3 to 6 inches for the Washington region.
The experimental American model (GFS-FV3) shifted the predicted position of the storm from Sunday the last two days to the south. Predictions for a lot of snow on Tuesday fell to little or no snow from Thursday. (TropicalTidBits, adapted by CWG) Canadian model: No snow within a radius of two provinces of the district. Light snow and gusts may leave from Fredericksburg to the south on Sunday afternoons until Sunday evening. A day ago, at this time, this model predicted a major blizzard for the Washington region. European model: no snow within a radius of two provinces of the district. Light snow and gusts possible Sunday evening from Fredericksburg to the south. The models described above represent the primary predictions in larger modeling systems that contain dozens of simulations. But even in this larger group of projections, the percentage of simulations predicting significant snow has dropped dramatically. For example, the European modeling system, which contains 50 simulations, has really supported the snow forecast for the Washington region. Of the 50 simulations: about 70 to 75 percent do not predict snow. Only 25 to 30 percent predicts at least one dusting. Only 10 percent predict at least two centimeters. Only one simulation (2 percent) predicts a minimum of 6 centimeters.
The European modeling system predicts a 10 to 20 percent chance of an inch of snow in the Washington area from Sunday to Monday. (WeatherBell.com) The American modeling system still holds a 10 percent chance of a major storm (of at least 6 inches) and a 40 percent chance of an inch. Models could still drive the path of the storm a bit to the north, which would increase the chance of at least some light snow in the region. This is something that we will continue to follow.