Philly dry spell hits 77 degrees Friday

Philadelphia will see its warmest day of the month on Friday.

The region is currently under the influence of a persistent high-pressure system. This pattern has controlled local weather for more than a week. Forecasters report that the system shows no sign of weakening during the current week.

Temperatures will rise sharply starting Thursday. Highs will reach the lower 70s on that day. Friday will bring the peak of the warmup with a high of 77 degrees. That figure is more than 10 degrees above the average for the end of October. Humidity levels should remain comfortable despite the higher heat index.

The upper-level ridge building across the central and eastern United States is the driver for this shift. Warmer air is spreading into the northeast as this ridge strengthens. Clear skies and light winds will accompany the rising temperatures. Nighttime lows will still drop, allowing for comfortable sleep conditions even during the afternoons.

The dry conditions extend into the holiday weekend. Saturday, Halloween, will feature a mix of sunshine and clouds. Temperatures are expected to stay in the lower to mid 70s. No significant rain is in the forecast for that date. Trick-or-treaters can expect temperatures in the 60s during the early evening hours.

Sunday will be slightly cloudier but remains mild. Highs should hover around 70 degrees with mainly dry conditions. A weak cold front caused the slight cooldown seen on Tuesday and Wednesday. The weather pattern shifts back to sunshine and warmth late in the week.

The seven-day outlook projects mostly sunny skies through Thursday. Friday will be sunny with a high of 77 and a low of 52. Saturday will see a high of 70 and a low of 51. Sunday will be partly sunny with a high of 72. Monday brings a chance of showers with a high of 72 and a low of 61.