ACTIVE WEATHER WEEK

An active week, weather-wise, is on tap for Philadelphia.

An upper air high pressure system has set up in the center of the country and disturbances are forecast to rotate around the the edge of high pressure system, moving through our area from the northwest almost every 24 hours.

Following another cool and dry day on Monday, clouds move in Tuesday.  The first disturbance approaches from the northwest Tuesday night with showers and thunderstorms.  A second and third disturbance is forecast for Wednesday night and  again Thursday night.

Here’s the current GFS forecast, with the three disturbances shown—

GFS forecast Tuesday midnight. (Click on image for a larger view.)

Expect some changes in the exact track (for instance, the current NAMNEST has the first disturbance moving  more to our south) and timing of each disturbance.

WEEKEND WEATHER FORECAST

A cold front will gradually move through Friday night. The main effect of this frontal passage will be a drop of dew points.   Skies will clear after daybreak Saturday.

A secondary cold front moves through Saturday evening.  Some sprinkles possible far northwest of the city Saturday evening.

Saturday —

  • Mostly sunny skies
  • High temp 81.2°sd 1.6° Dew points drop to the 50s.
  • light winds WNW 6-10 mph with gusts to 15

Sunday—

  • Sunny and cool.
  • High temp 69.6°sd 2.2°
  • Light winds NW 5-7 mph with gusts to 17