Saturday morning forecast

Synopsis:

 

There is an area of low pressure affecting our weather for today. It will cut across the north-central part of the Commonwealth, producing snow and sleet in the northern and western portions of the state. The southern and eastern parts of Pennsylvania will see more of a freezing rain and rain event. This should move out by tonight, leaving only the areas around Lake Erie with a few flurries. Then, tomorrow, we will see a bit of a break, with partly to mostly cloudy skies across the region. Monday, a new area of low pressure will move in, producing another round of a wintry mix. Any precipitation left over Monday night will change to snow, as a cold front is expected to pass through, giving everybody much colder temperatures through the rest of the workweek.

 

Short-term:

 

An area of low pressure will move from the southwest, cutting across the state today, giving almost the whole state one form of precipitation or another. North and west of the low, it will be predominantly a snow and sleet event, while to the south and east of the low, it will be mainly freezing rain and rain, as a sector of milder air tries to move in from the south. Where exactly the dividing line between the colder and milder air will be is not absolutely certain. The 00Z GFS model has the low cutting right along the middle part of Pennsylvania, moving northeastward. This would have the north and west parts of the Commonwealth getting mainly snow and sleet, while the south and east areas receive mainly freezing rain and rain. However, the 00Z and 12Z WRF model has the low moving through the northwest part of the state, which would keep the snow and sleet more to the northwest (areas including Erie and Bradford), while most other places get freezing rain and rain. The 12Z GFS model also has it moving through the northwest and north central part of Pennsylvania, keeping the snow and sleet further northwestward. In any case, there will be a hodgepodge of precipitation, so people need to take caution out there. Most of Pennsylvania is currently under a WINTER WEATHER ADVISORY.

For tonight, the precipitation should move out, leaving behind only a few possible snow showers around Erie and the northwest region near Lake Erie. Tomorrow should be dry, as a weak upper-level ridge moves through, giving most areas partly to mostly cloudy conditions. However, by Monday, another area of low pressure, bringing with it a cold front, will move towards the Commonwealth. The 540-mb. line will try to move up towards Pennsylvania on Monday, but won't reach us. Winds will be out of the S to SW, bringing slightly milder temperatures, which means another round of mixed precipitation. However, once the cold front moves through, any leftover precipitation will be snow, and winds will shift, coming from the W and NW. It will be noticeably colder Monday night and through the rest of the week ...

 

Long-term:

 

Much colder air will move in behind the front Monday night. Tuesday will be considerably colder, as a Canadian area of high pressure sweeps down into the Midwest, pushing colder air towards us as well. It will be partly to mostly sunny in many areas Tuesday and Wednesday, but temperatures will only be in the 20s and 30s throughout the state. Another chance of snow comes into the picture for Thursday as a low moves to the north. Friday, a reinforcing shot of Arctic air from Ontario comes to Pennsylvania, and temperatures will be even colder. The 510 mb. line will make its' way down to Pennsylvania Thursday night, persisting into Friday, so it should be quite cold.