An amplified jet stream moves a cold front through late Saturday afternoon into early evening.
Saturday will be sunny and mild for most of the day with high temperatures in the low to mid 60s. Clouds increase about 3-4 pm, then a brief light shower about 5-7pm with a dramatic shift and increase in winds from the northwest. Temperatures drop rapidly into the 40s.
Sunday will be mostly cloudy, continued windy and chilly with high temperatures only about 45.
It’s too soon to give my annual Winter Climate Outlook, but I’d like to share some observations about current weather trends.
We’ve been in a mild pattern, but a highly advertised jet stream amplification for late Saturday into Sunday will give us the first taste of cold windy weather for next week. We might have some light snow showers on Sunday.
For Wednesday before Thanksgiving, and Thanksgiving Day, the models have been showing another cold front moving through with showers early in the day Thursday. The intensity of the low pressure system with this cold front has been hard to model and it’s looking less strong with recent model runs.
The first week of December is looking very active across the country and cold in our area, as a more amplified jet pattern seems to be developing.
High pressure will again dominate Philly weather for this weekend, giving us fair skies and closer to average temperatures.
While much has been made of the chilly temperatures for Saturday, the actual expected high of 51 isn’t that far off from historical averages.
The dip in the jet stream giving us this cooler weather will relax by Sunday and temperatures will rebound to above average (60) by Sunday afternoon.
Truly cold weather has been conspicuously absent so far this Fall and the long range model forecasts don’t show much in the way of typical large latitude jet stream dips. So the general feeling is that truly cold weather may wait to make its appearance until late December or early January, just as it has over the past few years.