Philadelphia Area Weather Forecasts

Philly Weekend Weather Forecast -Early Edition

The closed upper low will remain to our west through Saturday, as moisture continues to stream in from the east and southeast.

Saturday looks to be cloudy.  The GFS and NAM continue with periods of rain, mostly in NJ, but extending into the PHL area.    As mentioned, forecast placement of precipitation in closed low situations is often inaccurate and difficult to model.  That said, the statistically based MOS (model output statistics) maintains a 50-60% chance of rain each 6 hour period, which is high.  So plan on a cloudy, wet day.    High  69.

(I think a peek at the short range  HRRR model Saturday morning will be needed to update and clarify the actual placement of the showers on Saturday.)

The closed low is expected to lift out on Sunday.  Mostly cloudy, maybe some sunny breaks.  Still a slight chance of a shower.  High 73.

As for Hurricane Matthew, current forecast tracks move it away from the NJ coast, although there are still some statistical ensemble model members that maintain a more westerly track.  This hurricane is already taking an unusually southern and western track, though forecast to so.  Still needs to be watched

Tropical Storm Outlooks

Tropical Storm Matthew -> Hurricane Matthew

Tropical storm Matthew is expected to become a hurricane within 24 hours.  Long range statical “ensemble” models continue to show the storm moving up the North Carolina coast next Wednesday -Thursday and then  possibly to the NJ coastline Friday, although the current trend is to start motion eastward into the Atlantic, minimizing effects here.

What is fascinating: the long range models have consistently showed a hurricane developing with this approximate track for more than a week.

With a closed low affecting our weather now and a strong tropical system developing, expect weather forecasts to be less reliable and changeable over the next week.

Tropical Storm Outlooks

“Interesting” Tropical Weather Possible Next Week

It’s way too early to take this seriously, but the GFS model has been showing a hurricane to develop and be blocked from eastern movement so that it hugs the mid Atlantic coastline sometime in the timeframe of next Wednesday thru Friday.  As depicted currently, this could easily rival hurricane  Sandy.  There have been several model runs showing this possibility.  Again, way too early, but this needs to be watched.

Weather… and Other Things 'Up in the Air'