Philadelphia Area Weather Forecasts

WEEKEND WEATHER FORECAST

Update Sat @ 9:30 PM — Sunday’s forecast for sunshine still looks good. High 49° ± 2°. Watching the Monday forecast.

This morning’s latest HRRR and RAP models have the sun breaking out between 2 and 3 PM in many areas.

HRRR 12z – Cloud ceiling height forecast for 3 PM Saturday. Many areas will have breaks in the overcast and sun at times. (Click on image for a larger view.)

Updated Sat @ 7:36 AM— Merry Christmas! The forecast specifics for today remain hard to pin down time-wise. The general trend is that there will be showers early, then a break and even some sun for a bit, then more showers about noon, followed by another break and even some sun about 1-2 PM, then more clouds and showers.

High temp 55.6º ± 3.7º Blue Bell based on the latest NBM model. (The high standard deviation -3.7º reflects the uncertainty in the model forecasts for today.)

The current radar doesn’t match favorably with any model forecasts, so it’s still a lower than usual confidence forecast.

Sunday still looks sunny.

A low pressure system in western NY state will have it’s associated warm front move through after midnight tonight (Friday). It’s associated cold front will move through during the evening Saturday. The front will stall to our south and return on Monday as a warm front. In between, Sunday will be sunny.

There’s been a lack of clarity about Saturday’s forecast details, as covered in my previous post.

NAM model forecast for 8 AM Saturday. Showers depart early morning, but the showers well ahead of the associated cold front arrive late morning. (Click on image for a larger view.)

Saturday

The showers associated with the warm front will move through before daybreak and into the early morning. There’s been a lack of clarity regarding the early morning showers placement, but I’m going to lean on the latest NBM to make the call.

Most models are in agreement with showers returning late morning well ahead of a weak cold front. (The main front moves through on the evening.) Showers will be light. It will become WINDY late morning. There may be some clearing after 1-2 PM although that’s not a certainty.

High temperature 56º ± 3.0º (NBM Blue Bell)

NBM (20z) clouds and precipitation 3PM. Some clearing but high uncertainty about cloud cover (red contours) with showers remaining north. The showers to our west move in the late afternoon and evening with the cold front.

The main cold front moves in in the evening (possibly with additional showers, but a low chance.)

Sunday

The front moves to our south and fair weather moves in. It will still be mild.

High temperature 50.3º ± 2.4º (NBM Blue Bell)

Looking Ahead…

The front that moved through Saturday will return as a warm front Monday. There’s the possibility of light, non-accumulating snow early Monday morning.