Last night, some of the computer models suggested Wednesday’s Nor’easter may develop far enough offshore to spare New York and New Jersey from the brunt of the storm. Unfortunately, this morning’s models have nudged the storm closer to the coast again, putting back in play the possibility of an unwelcome blow for areas devastated by Superstorm Sandy.
After reviewing the overnight models which shifted the storm farther out to sea, forecasters at the National Weather Service gently backed off predictions for highs winds and coastal flooding. The NWS Hydrometeorological Prediction Center wrote in its morning discussion:
RECENT MODEL GUIDANCE SUGGESTS THIS AREA OF DISTURBED WEATHER MAY BE NUDGED OFFSHORE A BIT FURTHER THAN PREVIOUSLY THOUGHT WHICH WOULD LESSEN THE IMPACTS OVER THE NORTHEAST...
On its Facebook page, the Eastern Region of the NWS added:
The winds will not be quite as strong, with the windy conditions primarily right along the coast. Wind gusts along the coast could still reach 40 to 50 mph, especially over Cape Cod.
- The track further east will also cause the winds to be more northerly than northeasterly, which will reduce the potential coastal flooding.
But the latest models suggest the NWS’ previous warning that the storm represents a “dangerous situation” for the regions hit hardest by Sandy may turn out most prescient - although a shift back out to sea could happen too.
This is a very delicate forecast where slight shifts in where the storm develops and how rapidly will have profound effects on local conditions.
The following impacts remain possible for the coastal Delmarva through southern New England Wednesday and Wednesday night:
* Winds: North to northeast winds of 20 to 35 mph with gusts of 50 to 60 mph are possible. This could bring some scattered power outages.
* Seas: Wave heights in the surf zone along the coast are expected to build into the 6 to 10 foot range.
* Coastal flooding: Moderate flooding is anticipated around the times of high tide on Wednesday and Wednesday night with a storm surge of 3-4 feet.
* Forecast tides levels are expected to be near 7.5-8 feet above mean lower low water, including in Sandy Hook (NJ), Sandy Heights (NJ), Atlantic City (NJ), Cape May (NJ), Breakwater Harbor (DE), and Rehoboth Beach (DE).
* For New York City, the NWS provides the following forecast for coastal flooding: A SURGE OF AROUND 3 TO POSSIBLY 4 FT STILL LOOKS POSSIBLE WITH THE MID TO LATE WEEK COASTAL STORM. STORM TRACK...TIMING AND INTENSITY UNCERTAINTIES ARE SUCH THAT MULTIPLE TIDE CYCLES COULD EXPERIENCE WIDESPREAD MINOR TO MODERATE COASTAL FLOODING. MAJOR FLOODING BASED ON PRE-SANDY BENCHMARKS NOT EXPECTED
Coastal flood, high wind and storm watches remain in effect for this entire corridor (see image above right).
In an informational briefing, the NWS office in Philadelphia makes the following important points:
* Major coastal flooding is still a slight possibility; the high tides of most concern are the ones around midday
* There will be moderate to severe beach erosion during this event.
* Impact from coastal flooding and strong wave action will be worsened due to effects of Coastal Storm Sandy.
* Dunes have been weakened or washed away; bulkheads damaged or destroyed.
* Coastal storm defenses have been seriously compromised.
Beyond wind and high seas, cold temperatures and snow are possible as well in this corridor especially as you head inland 50-100 miles or so in areas with a little elevation. Philadelphia could see a couple inches of wet snow with higher amounts in the Poconos. New York City and Boston may have a brief period of wet snow, but are likely close enough to the ocean such that precipitation would change to rain.
Total rainfall for areas right along the coast from the Delmarva to New England should be in the range of 1-3 inches (see map).
What about conditions in Washington, D.C. and Baltimore? We are right on the edge of getting some precipitation (rain/snow mix) or nothing. We will have an update mid-afternoon focused on this area.