After a quick look at the morning data, it still looks like our part of Virginia will have minimal effects from this week’s nor’easter.
Regarding precipitation, the question is how far westward the precipitation shield moves, as the storm center will be much farther east. The secondary question is whether it will be cold enough to support snow.
While the ECMWF has been bullish, and fairly consistent, on putting down a stripe of accumulating snow from Richmond to Washington during Wednesday evening, I am still not sold. I have much respect for that model, but the ground is still fairly warm for substantial accumulation. And model-watchers remember that the ECMWF threw down 4″ of snow in Danville from Sandy a few days before impact. We see how that worked out.
Having said that, if the snow does wait until after sunset to develop, the actual surface temperature will be lower, and accumulation on grassy and elevated surfaces is a distinct possibility 30 miles either side of the I-95 corridor in Virginia.
The ECMWF is also the most aggressive in sending any precipitation back into our part of the state. Time frame is Wednesday afternoon and night, but the amount is less than a 0.25″ of liquid. The measurable precipitation line backs as far west and south as South Boston – Smith Mountain Lake – Roanoke. Leaving Martinsville and the New River Valley with zero precipitation.
So, this is a very close matching of storm track and timing. While still too early to give up on any snow, it is not the most likely scenario. Like last week, elevation will play a substantial role in precipitation type. And to emphasize, there is little reason to expect anything else but light precipitation in our part of Virginia.
Best guess for Greater Lynchburg would be for some very light rain to develop late Wednesday afternoon, perhaps mixing with some wet snowflakes, but simply too warm to see any accumulation. Precipitation would end late Wednesday night, with sun breaking from between the clouds by Thursday afternoon. A chilly north breeze also develops Thursday, so afternoon temperatures will probably be stranded in the 40s.
Across Southside Virginia, chances are even lower for snow… or for any precipitation for that matter. Remember, however, that this storm will have its beginnings in the Carolinas, so some very light rain could wander into the communities near the North Carolina state line as early as Tuesday evening.
But it is very clear that the worst of this storm remains east and north of Lynchburg and Southside Virginia.
And to be sure, it will be a windy, cold, and wet time Wednesday (south) and Thursday (north) from the Chesapeake to New England. Light to moderate coastal flooding is expected, depending on how individual areas did through Sandy, but as mentioned earlier, the storm is absolutely not another Sandy. And accumulating snow is not expected along the coastline. Inland areas, toward Hagerstown, Harrisburg, Scranton, through the Adirondacks and Berkshires are at biggest risk for a high-impact (greater than 4″) snow.
Yes, there could be a westward shift in the track, but to this point, the data has been fairly consistent, so I do not expect a dramatic change by tomorrow. Nonetheless, refinements in the forecast should be expected tomorrow.
Update. 2:45pm Monday
New simulation from the ECMWF model is about 150 miles farther east with the center of the storm and its precipitation shield. This shift brings it in line with most of the remaining computer simulations. Both rain and snow stock down substantially for our part of Virginia. Also dramatically reduces (the already small) chance of snow from Washington to Richmond.
Ironically, this track brings up the chance for accumulating snow in Greater Philadelphia Wednesday night, although the chance there is still only marginal. Onset still 48 hours away, so still time to iron details out tomorrow.