Surface high pressure with an upper broad cyclonic flow will provide colder than average temperatures, light winds and sunny skies
this weekend on Saturday and some cloudiness on Sunday in Philadelphia.
Saturday will be sunny and cold. High 39. (Average high is about 45). Winds will be light.
Sunday will be similar- sunny and cold with light winds. High 39.
Updated Fri 10:30pm Sunday will have mid and high level cloudiness based on the GFS model. High 38
Outlook: A cold and dry week ahead. Some heavy precipitation (likely rain or mix to rain) next Friday into Saturday.
Saturday Morning Update 8 AM
The forecast is on track with rain starting about 4-5 PM Saturday. High 44.
For Sunday, chance of showers in the morning, then cloudy with a chance of light showers (NBM and GFS) in the afternoon. The NAM continues with a mostly dry and cloudy afternoon. High 63.
Forecast from Friday night:
An approaching low pressure system in the west with it’s associated warm front will pass through our area late Saturday evening into Sunday morning.
Saturday will start chilly with a mix of sun and clouds with temperatures not warming to 40 until noon. Highs will be in the mid 40s during the late afternoon. Clouds move in during the afternoon Saturday and rain starts about 4-5 PM. Rain will become moderate during the evening and night.
The warm front passes north of us early Sunday morning. The GFS and the NBM maintain some showers lingering into the afternoon, while the NAM has the possibility of rain ending around noon. It’s a tough call on whether we’ll have clearing in the afternoon, but I’m feeling the GFS may be holding onto the showers too long. High temperatures 63-67.
Saturday Update 9 AM
While the GFS LAMPS maintains high chance of rain arriving by 12-2 PM, the recent runs of the NBM show a slightly later arrival of the rain: 1-3 PM. A small change.
Cold high pressure move off to the east. A disturbance approaching from the southwest will bring rain and milder temperatures on Saturday,
Saturday will start cloudy and temperatures will rise from below freezing into the low 40s by 1PM. Arriving with the milder temperatures will be rain. The rain may arrive as early as 12-2 PM. The rain will become heavy late afternoon into the evening. Temperatures continue to rise into the 40s.
The low pressure system that brought us the rain will be gone before daybreak Sunday. Sunday will be partly sunny and a bit warmer than average for this time of year. High 52. (Average high about 50).
Outlook: Rainy on Monday and another outbreak of cold air expected by Tuesday, although not as cold as we’ve had the past few days.
Some instability cloudiness developed today (Friday), not captured by the models.
High pressure will build in tonight into Saturday. Mostly sunny skies early Saturday will allow high temperatures to reach 43. (The NAM is suggesting some instability cloudiness may develop as well.)
Additional clouds move in during the late afternoon Saturday as a return flow of moisture rides up over the edge of the high pressure system.
Sunday is looking mostly cloudy and chilly as the upper level moisture continues to ride over the edge of the slowly retreating high pressure system. High 43.
Outlook: a disturbance riding over the upper ridge may bring some light precipitation (snow) Monday evening. Will watch. Thanksgiving day looks quiet, next weekend rainy. The final week of November may be mild.