New York City on the edge

Even if we take the computer forecast models at their word, we go from a few inches of snow to a foot and a half in the distance from Newburgh to the Bronx, from the north boarder of Connecticut to Long Island Sound.  A little wobble in a wobbly spinning storm means a large change in the results.  More cold air will help the precipitation stay all snow, but also bring drier air and choke off the snow.  Winds off the water will add more moisture, but the ocean is warmer than normal, so even more moisture, but warmer air gets mixed in.  (Warmer ocean from December’s heat waves.)  More likely for DC and perhaps Phily to be deep in the snow (see Capital Weather Gang )

From the National Weather Service NYC…. 6pm forecast discussion….

MODELS DIFFER ON THE PACE AT WHICH THE CUT OFF LOW AND THEN
OCCLUSION TRACK TO THE EAST NORTHEAST OVER THE WEEKEND. THIS RESULTS
IN DIFFERENCES IN THE TIMING/STRENGTH/PLACEMENT OF THE ASSOCIATED
SURFACE LOW. WHAT THE MODELS ARE IN FAIRLY GOOD AGREEMENT ON IS . .
A HIGH WILL REMAIN SUFFICIENTLY STRONG AS IT RETREATS TO THE
NORTHEAST TO KEEP A SUPPLY OF LOW LEVEL COLD AIR FEEDING DOWN INTO
THE REGION THROUGH THE STORM. AS A RESULT...EXCEPT FOR POSSIBLY
MIXING WITH RAIN/SNOW MIX OVER EASTERN AND SOUTHWESTERN SUFFOLK
COUNTY SATURDAY AFTERNOON/EVENING...PRECIPITATION SHOULD BE ALL SNOW
DURING THE EVENT.

Then… timing?

THERE IS SOME UNCERTAINTY IN HOW RAPIDLY SNOW PUSHES NE INTO THE
CWA...WITH SOME POSSIBILITY THAT MOST...IF NOT ALL...OF THE CWA DOES
NOT RECEIVE ANY SNOWFALL UNTIL SATURDAY MORNING.

Perhaps not a flake on Friday?

Then…. how much?

CONFIDENCE HAS INCREASED THAT THE STORM WILL BRING MEASURABLE
PRECIPITATION INTO ALL BUT NORTHERN INTERIOR PORTIONS OF THE TRI-
STATE.... . . . PRECIPITATION SHOULD TAPPER
OFF OVER MOST AREAS SUNDAY MORNING.... . . .

CONFIDENCE IS ALSO INCREASING IN THE IDEA THAT MOST...IF NOT ALL OF
THE SOUTHERN 1/2 OF THE CWA WILL RECEIVE AT LEAST 6 INCHES OF
SNOW...EXCEPT FOR POSSIBLY EASTERN SUFFOLK COUNTY...WHERE RAIN
MIXING IN COULD LIMIT AMOUNTS. FARTHER NORTH...IT IS BECOMING MORE
CERTAIN THAT AN ADVISORY LEVEL (3-6 INCH RANGE) SNOWFALL SHOULD
OCCUR...EXCEPT FOR ACROSS FAR N PORTIONS OF THE LOWER HUDSON
VALLEY/SW CT...WHERE 3 INCHES OF SNOW IS STILL IN QUESTION...BUT
DEFINITELY POSSIBLE. EVEN IN THE NORTHERN 1/2 OF THE CWA...WARNING
LEVEL SNOWS ARE STILL WITHIN THE REASONABLE REALM OF POSSIBILITIES
FOR THIS SYSTEM. GIVEN THE UNCERTAINTY...AND THAT MOST...IF NOT ALL
THE SNOW WILL NOT START FALLING UNTIL SATURDAY...HAVE DECIDED NOT
TO ISSUE ANY WINTER WEATHER HEADLINES WITH THIS ISSUANCE.

The storm brings strong, sustained winds, especially late Friday night into late Saturday, with tides well above normal, helped by the full moon, until the storm gets by us and winds come from the north.

In any case, get ready to be in a safe place by Friday night and ready to stay for a while.

 

 

 

 

 

 

 

 

 

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