7:00 AM | **Slow-moving storm system to bring us rain here late Wednesday into Thursday...strong NW winds, colder conditions to follow**

6-Day forecast for the Philadelphia, PA metro region

Today

Mainly sunny, becoming breezy, quite mild, highs in the low-to-mid 60’s (normal high is now 55 degrees at PHL); NW winds increasing to around 10-20 mph

Tonight

Partly cloudy, brisk, chilly, lows in the mid-to-upper 30’s

Tuesday

Mainly sunny, not quite as mild, but still above-normal, near 60 degrees for afternoon highs

Tuesday Night             

Mainly cloudy, chilly, maybe a shower, low-to-mid 40’s for late night lows

Wednesday

Mainly cloudy, mild, chance of PM showers, lower 60’s; rain likely at night, slight chance of a thunderstorm

Thursday

Clouds and limited sun, becoming windy, colder, chance of rain showers and a few flakes or ice pellets can mix in at times, near 50 degrees

Friday

Partly sunny, windy, cold, chance of showers, middle 40’s

Saturday

Partly sunny, still windy, cold, upper 40’s

Discussion

The first half of the new work week will be relatively quiet and mild, but the weather turns quite active later this week as a deepening upper-level trough dives into the Mid-Atlantic region. This strong upper-level trough will become a slow-mover thanks to strong blocking high pressure to the north over northeastern Canada. At the surface, an initial low pressure system will head towards the Great Lakes in the late week time period and then a secondary low should form near the northern Mid-Atlantic coastline.

The end result of this unfolding scenario should be occasional rain here from later Wednesday into Thursday morning and there is a slight chance of a thunderstorm. Scattered rain showers are then likely from Thursday afternoon through the day on Friday as the atmosphere will remain quite unstable and it is not out of the question that a few flakes or ice pellets mix in at times. In terms of temperatures, after a mild day on Wednesday ahead of the cold front, it turns noticeably colder on Thursday and it’ll remain cold on Friday with highs limited to the middle 40’s to close out the work week. The winds will become quite strong on the backside of this low pressure system from a northwesterly direction and should last all the from later Thursday through much of the upcoming weekend given the storm’s slow movement. One final note, skiers in the northeastern states may be happy after this late week event as early season accumulating snow is quite likely from upstate PA to upstate NY to interior New England.

Meteorologist Paul Dorian
Arcfield Weather