Saturday morning forecast discussion

Synopsis:

 

We will see a couple of systems affecting our weather over the next few days. Currently, an area of low pressure is moving to our south, giving areas of southern PA a few snow and rain showers. This will scoot out (along with the precipitation) by the end of the afternoon. We will see a break for most of tomorrow before a warm front moves through the Commonwealth. Some rain will be seen as a result of this, but not nearly as much as what we will see with the cold front associated with it Monday night. The 540 mb. line will be way to our north on Monday, which will ensure mild to warm weather across the state, and we will see temperatures mostly in the 60s and 70s. This will create a nice divide between colder and warmer air for when the cold front moves through, which could fire up a few thunderstorms along itself. Tuesday, we return to a chillier pattern, with highs where they will be this weekend. There could be a gradual warming trend afterwards, with temperatures approaching April normals.

 

Short-term:

 

One area of low pressure is moving to the south of the state today, giving areas such as Pittsburgh and Johnstown a few rain or snow showers. This will continue through the afternoon - it won't be anything significant. Then, we get a break before the next storm system moves in. A warm front will move through Sunday evening. It will most likely go across the northern areas of Pennsylvania - the 00Z and 06Z runs are pretty consistent with the frontal position. The 540-mb. line will have moved north as well, as a precursor to the warm front. So, for Monday, we'll have warm air across the state, with southerly winds blowing, and only a few showers in the very northern areas. Then, the cold front will sweep through. This looks to happen sometime Monday night. The 00Z GFS and 06Z have the cold front starting to go across PA at about 00Z Monday evening (8 PM), and the 12Z WRF has it moving through starting at about 03Z Monday night (11 PM). The 06Z GFS actually has the front knocking on PA's door by 18Z on Monday (in the afternoon). Since the front is clashing with some pretty warm air, we could see a few thunderstorms with the approach of the front. It seems more likely at this point, based on model consensus, that the front will pass sooner rather than later, but the timing is something to be aware of. Precipitation amounts (heaviest) will probably be about an inch, with greater amounts possible in any embedded thunderstorms. After the FROPA, Tuesday looks to be drier, with only a few scattered showers remaining. Then, we get into a more tranquil pattern for the rest of the week ...

 

Long-term:

 

We will see a slight warming trend through the rest of this upcoming week, with temperatures approaching more normal levels for April. There could be a few rounds of showers - one on Tuesday night into early Wednesday, passing through the southwestern corner of PA, and one with another warm front passage sometime Wednesday night. Thursday night or Friday looks to be when we'll see more widespread rain again, as another cold front passes through. Otherwise, it will be milder and not quite so unsettled as it looks to be short-term.