YET ANOTHER MODEL CHANGE!

Last night’s models continue to change with the forecast for the two storms that’s been forecast for Tuesday through Wednesday evening.

Many deterministic models (NAM, NAVGEM (Navy) and to some extent the ECMWF (European) now suppress the storms to our south, even on Tuesday!  Only the GFS and Canadian models have a precipitation shield that extends into the Philadelphia area as the storm moves to our south.    This would mean less  QPF, although it may mean colder temperatures, flipping things to more snow rather than rain.   (We’re still looking at small amounts, falling in March during the daytime->little accumulations.)

On the other hand, the statistical versions of the models (the ensembles), consistently show some signal for mixed precip in Philadelphia for both Tuesday and Wednesday.

The Wednesday storm also seems to be suppressed to our south and east, with most, but not all models.

So right now, it’s looking like the brunt of both storms will miss us, with the Tuesday storm northern fringe just affecting us and the Wednesday western fringe either just affecting us or missing us.

Expect other changes!

[su_note note_color=”#ebf2d9″]Sunday Noon Update: This morning’s NAM and GFS continue with the trend to suppress the two storms’ precipitation to our south and east both Tuesday and Wednesday.  It appears that mostly Delaware and Maryland will be affected,  with only fringe effects into southern counties of SE Pennsylanvia.  Philadelphia  and areas north will be minimally affected, as it appears now.  [/su_note]

 

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.

Weather… and Other Things 'Up in the Air'