PHILLY TUES-THURS STORM UPDATE

Tonight’s NAM data just became available.  Here’s a quick update.

A mixed precipitation event for Tuesday.  Snow before daybreak ( 1-2 inches possible by daybreak), then changing to rain or rain mixed with snow in most of the Philadelphia area, then back to light snow before ending. Little or no final accumulation expected,  except on grassy surfaces expected at this time.

Precip ends Tuesday night .  Latest NAM  has second storm  on Wednesday hugging coast, instead of going out to sea.  Some snow possible. This supports the statistical models from earlier today.   Too early to give specifics about Wednesday.  (It’s difficult to get accumulating snow in March during daytime hours. ).

It’s l daylight saving time— the GFS data won’t be available until after midnight for Wednesday’s forecast.

PHILLY STORM OUTLOOK FOR TUES-THURS

Last night’s two model runs continue to show some snow and mixed precipitation starting Monday night into Tuesday.  Current track is a bit further south, increasing chance of snow vs. rain, but QPFs are less.

We’re NOT talking about a major snowstorm for Philly; more likely a significant snow for areas much further inland.  Details about specific accumulations still uncertain, but it appears more like a 3 inch range total with sleet and possible rain mixed in for Philly.  The usually “more likely on grassy surfaces” instead of roadways.  That’s the current best guess.

What’s more significant with the latest model runs- the second low that forms on Wednesday is now looking like it might move out to sea, essentially missing us on Wednesday;  this is true of the deterministic models (GFS, CMC, ECMWF etc).   The statistical models still show a ”signal” for snow in our area on Wednesday, so we’re not out of the woods yet.

This is a complex binary-type system.  Still too early to be sure about  details, expeciallly with the second low for Wednesday.  Changes likely.