UPDATE… Wednesday evening….don’t get too set on a forecast yet….presently looking at snow starting sometime during the day on Saturday….how long will it stay snow?
As the National Weather Service says….
MODEL GUIDANCE DIFFERS HOWEVER ON
TIMING…SPEED…AND STRENGTH OF THE LOW. IN ADDITION…MODELS ARE
ALSO NOT IN COMPLETE AGREEMENT WITH THE STRENGTH AND EXACT POSITION
OF A HIGH PRESSURE SYSTEM…NORTH OF THE CWA [County Warning Area, i.e., the NYC metro area] …WHICH WILL BE A MAJOR PLAYER IN THIS EVENT.
Yes, Saturday morning, another storm may arrive.
Much is uncertain about this storm, but it looks bigger than Tuesday’s storm.
The computer models are bringing it closer to the coast, which would let more warm air in and change the snow on Saturday morning to rain – at some point.
But this is our best estimate at this time and we have a long way to go to Saturday. It’s enough for people to think about how to be ready, based on their plans for the weekend.
Keep listening for updates as we get closer.
In the meantime, the Philadelphia office’s discussion is useful to read to understand the issues the forecasters are dealing with along the northeastern coast of the US for Saturday’s situation.
From Tuesday afternoon’s Weather Forecast Discussion:
THEN ALL ATTENTION TURNS TO A LOW PRESSURE SYSTEM GETTING ITSELF
TOGETHER OVER THE LOWER MISSISSIPPI RIVER VALLEY. CLOUDS FROM THIS
SYSTEM WILL BEGIN TO OVERSPREAD THE REGION FROM THE WEST LATE
FRIDAY NIGHT, WITH PRECIPITATION ARRIVING SATURDAY MORNING.
MOST MODELS ARE IN AGREEMENT THAT PRECIPITATION WILL BEGIN AS SNOW
EVERYWHERE EXCEPT PERHAPS ALONG THE IMMEDIATE DELAWARE AND SOUTH
JERSEY COAST…BUT THEN AS WARMER AIR MOVES IN, A CHANGE OVER TO
SLEET AND RAIN WILL TAKE PLACE PROGRESSIVELY INLAND FROM THE
COAST. THE 12Z GFS [American model] IS COLDER THAN IT`S PREVIOUS RUN, AND MUCH
COLDER THAN THE LATEST ECMWF [European model]. THIS DIFFERENCE BETWEEN THE GFS AND
ECMWF COULD BE THE POSITION AND STRENGTH OF THE LOW DESCRIBED BY
EACH MODEL, BUT A LOT CAN HAPPEN BETWEEN NOW AND THE WEEKEND, SO
STAY TUNED. AS THE SYSTEM GETS WOUND UP OFF THE COAST, ONSHORE
WINDS WILL INCREASE, ESPECIALLY SATURDAY NIGHT. WILL A FULL MOON
APPROACHING ON THE 17TH, WE WILL NEED TO KEEP AN EYE ON THE TIDAL
SITUATION, BUT THIS SYSTEM WILL BE MOVING QUICKLY, SO ANY COASTAL
FLOODING SHOULD BE MINOR.
THE LOW PRESSURE SYSTEM MOVES AWAY SUNDAY AFTERNOON AND NIGHT,
FOLLOWED BY ANOTHER STRONG HIGH PRESSURE SYSTEM FROM THE UPPER
MIDWEST. THIS MEANS MORE COLD WEATHER FOR THE NEW WEEK, BUT
PERHAPS NOT QUITE SO COLD AS WHAT WE`LL EXPERIENCE WEDNESDAY INTO