Hurricane Sandy Discussion 2

Overall, there has not been a large change in the thinking on Sandy and its effects.

NHC 5pm Forecast Advisory on Hurricane Sandy. Note the level of uncertainty late this weekend and early next week.

Sandy is a formidable Category Two hurricane this evening, and will be exiting The Bahamas overnight.  There seems little doubt now that the storm will hook back into the East Coast.  The biggest question is how soon, and how sharp the turn will be.

As mentioned yesterday, the GFS has been catching up with the ECMWF simulation.  They are not in total agreement, as the ECMWF has been more consistent in its last three simulations with a track that brings it closer to the Virginia Capes (daybreak Monday), across the Chesapeake Bay, and toward Washington, DC (by Tuesday morning).

The NHC (above) track is closer to the GFS solution, holding Sandy a bit further offshore, then slamming it into the Jersey Shore on Monday evening.

Both of these outcomes are likely.  But their differences have large implications for our part of Virginia.

We are thinking that the track will be just to the left of the primary NHC track, which leans toward the ECMWF solution without following it exactly.  Here’s how we envision it playing out in our part of Virginia:

Sunday: Rain moves in from the southeast and advances toward the mountains.  Heaviest rain holding toward Emporia, Richmond, but heavier spells of rain develop in Greater Lynchburg and Southside Virginia.  Wind increases to 10-25 mph from the north, but still nothing serious.  Expect the rain to wait until afternoon in most locations.

Sunday night and Monday: Moderate to heavy rain across much of the area, with winds 15-35 mph. Gusts to 40 mph likely along the Blue Ridge Parkway.  Signs of a sharp cutoff to the rain on its southern edge, which means the rain could stop early in the Southside communities.  Total rainfall be the end of Monday will vary widely.  Some places as little as a quarter inch, while other could get 2 inches.  As a general rule, areas north and east (Amherst, Appomattox, Nelson Counties) in the viewing area will have more rain than those south and west (Montgomery, Pulaski, Carroll Counties).

NOAA rainfall forecast for next 5 days. Note the rapid drop-off from 7″+ in New Jersey to less than a tenth in our part of Virginia.

The NOAA map above follows the NHC track.  A shift to the left in the overall track of Sandy drags that heavy rain to the southwest with it.

As the storm moves further northwest Monday night, the cold air that is now advancing across the Plains will push into the Appalachians. Winds will continue strong (15-35 mph), but turn from the west and northwest.  This would bring heavy accumulating snow to the high terrain of West Virginia (perhaps more than 2 feet).  However, in a strong west wind, it is difficult to drag that snow down to the elevations of Lynchburg and Danville.

So, for Monday night and Tuesday, expect gusty winds and snow showers in the higher terrain.  Most likely to see that in Alleghany, Bath, Craig, Giles, Montgomery, Pulaski Counties.  Perhaps some snow squeaks into the higher terrain of Amherst, Nelson, Roanoke, Rockbridge Counties.  Accumulations are not likely, but, it is still too early to discount the possibility entirely.

Those who have been following the ECMWF solution will know that the last couple of runs suggest a few inches of snow as far south as Danville.  Certainly plausible, but I am simply not convinced that the air will be cold enough… nor the moisture deep enough… for a long enough period of time… to make it happen.  Give it another 36-48 hours and let Sandy get closer to the coast.

The consistency of the winds from Sunday night through Tuesday will do a number on the trees.  There will be lots of blowing leaves in the air during that time.  There will also be areas of wet leaves on the roads, cutting back traction.  Think about those things when driving around.

In the Northeast, this still appears as if it will be a devastating storm.  Coastal and river flooding, widespread power outages that will last for several days, and massive tree damage are all very likely early next week.  Huge impacts on air travel. I expect to see scenes of people stranded in airports on the news next week.

On Virgina’s coast, the approach of the storm on Sunday will bring a strong east wind into Virginia Beach and the Eastern Shore, so that is when the coastal flooding will develop. Then, as the center of the storm moves north or northwest of the Virginia Capes Sunday night and Monday, the wind will turn more from the north and northwest, shifting the coastal flooding threat to the northern side of Metropolitan Hampton Roads.  Torrential rain is also expected Sunday night and Monday there, making travel even more difficult.

It may be a good idea, whether in Virginia or the Northeast, to fill the car up in the next 24 hours, get some extra bottles of water, non-perishable foods, and batteries.

To re-emphasize, this is still one of the worst scenarios for Virginia.  Small changes in track in the next 36 hours make a huge impact.  This entire thing could break better or perhaps even slightly worse in that time.  Modifications will be made to the forecast.  Hopefully for the better. Thanks for following along.

About seansublette

Meteorologist at Climate Central. Broadcast meteorologist in Virginia from 1995 to 2015. Born and raised in Richmond, VA. Penn State alumnus. Loves baseball and the rock band Rush. Views are independent of my employer. Past performance does not guarantee future results.
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