The greatest threat Sandy poses to the Washington, D.C. area is damaging winds and to some extent flooding rainfall.
While Sandy will be at sea this weekend, a last-minute left hook scenario is becoming more likely.
How nasty wind and rain would be in the District and nearby areas on the I-95 corridor will depend on where landfall occurs. A landfall in New England would have much less impact than a westward landfall across the Delmarva.
At this point it appears a doomsday track northwestward across southeastern Virginia is not so likely in terms of tidal concerns on the Chesapeake Bay and the Potomac River. The wind flow would not be right for such an event.
However, a westward path over the Delmarva would bring serious coastal flooding and wind damage to the beaches. The same path would bring locally heavy rain, flash and urban flooding potential on the western flank of the storm, in the Washington, D.C. and Baltimore areas.
Even if Sandy cruises into New England, a period of strong west to northwest winds could develop over Virginia and Maryland as colder air rushes in, perhaps enough to cause downed tree limbs and power outages.
Ripple-effect flight delays could build Monday and Tuesday from the Midwest to the South caused by direct impact from Philadelphia northward to New York City and Boston.
A train of storms will slam into the Northwest United States well into next week and perhaps through much of December.
Downpours will continue the threat for flooding across parts of southern India this week.
Tens of thousands will gather in rainy and mild conditions at 30 Rockefeller Plaza in New York City on Wednesday, Dec. 2, 2015, for the 83rd annual Christmas tree lighting.
Rain will spread across much of the Eastern states into the second day of December 2015.
Snow will linger across parts of the northern Plains to the Upper Midwest as December begins.
Following several days of dry weather, a weak area frontal boundary will bring rainfall to northern France Thursday night into Friday.
Casper, NY (1982)
22" of snow. 4" shy of the record for all of December.
Dubuque, IA (1985)
Blizzard-like conditions brought an all time record 18.6 inches of snow.
Alta, Utah (1951)
64.0" snow, greatest single snowstorm in state's history (2nd-7th).