A weak front will move through Philadelphia in the early morning hours Saturday, accompanied by some showers, mostly before daybreak.
I’m going to try something for this forecast version- it will be based on the newer statistical models– the new National Blend of Models (NBM) and the new Ensemble Kernel Density Model Output Statistics. (EKDMOS). We’ll see how this goes. 🙂
Saturday will start cloudy, but skies will begin to clear during the mid morning hours and partly sunny skies is expected for much of the day. High will be between 61 (NBM) or 66 (EKDMOS) . It will be windy!
Clouds move in later Saturday afternoon as a strong secondary cold front moves through. More showers possible during Saturday night.
Sunday will be mostly sunny with some clouds, chilly and windy with a high of 49(NBM) to 52 (EKDMOS).
(I’ve been incorporating the experimental NBM and EKDMOS for these forecasts over the past year. The EKDMOS is pretty good with forecasting high temperatures. The NBM 3.1 , which now includes the European Models in the blend, was promoted from experimental to operational on Oct 3rd. Let’s see how it does this weekend.)
Look for an update tonight.
Forecast Update Friday 6 PM
The forecast remains on track. Saturday, after pre-dawn showers, becomes mostly sunny with some periods of clouds. Windy. High 63. Some sprinkles Saturday night as a secondary cold front moves through. Sunday is mostly sunny, windy and chilly. High 50.
This weekend’s forecast postmortem: The NBM did pretty good with the high temperatures, winds and precipitation (including Sunday’s brief shower that occurred about 8 AM instead of the predicted 7 AM.) BUT, it did very poorly with the cloudiness/sky cover prediction on both days. It was much cloudier than the NBM forecast. I’ve noticed this in past months. So I’ll have to go back to the GFS humidity fields for cloud cover in future forecasts.
High pressure that brought the easterly flow with cooler and dry weather today will depart as a warm front moves slowly through over the day on Saturday. The warm frontal passage is expected to be dry.
We had some light drizzle Saturday morning that was not predicted be the models. Currently, skies should start to clear with some sun in the early afternoon. Unseasonably warm and humid conditions for Sunday afternoon.
Saturday is expected to be mostly cloudy with gradually increasing humidity. Skies may brighten at times, especially mid to late afternoon. Highs near the average for early October, in the low 70s.
As the front moves north late Saturday, the clouds will lift and we’ll have warmer temperatures in the evening with dew points in the mid 60s.
For Sunday, partly to mostly sunny skies, unseasonably warm and humid. Highs near 83.
It’s been a long time since I was able to post a forecast early on Friday for the upcoming weekend and have confidence that things wouldn’t significantly change in a day or so.
The forecast situation for this weekend looks to be different, where high pressure builds in from the northwest and centers itself over PA, heralding in what has become an anomaly– an extended period of dry weather!
Skies are expected to clear Friday afternoon and sunny skies, light winds and lower dew points should be in store for both Saturday and Sunday. Highs on Saturday about 72 and Sunday about 74. Enjoy!
Currently, the next chance for showers will be in over 7 days from now.