Monday, October 01, 2012

Trending Colder This Weekend, Eventually...

There's a good bit of agreement in place that a cooldown will take place at some point towards the end of this coming weekend. A ridge will push up along the West Coast late this week, which will help push down a trough in the Eastern US. A cool front looks to push east through Canada, trailing down into the Lakes and eventually Northeast for Friday night into early Saturday.

There's uncertainty about how this front behaves as it gets down to our latitude -- especially as computer modeling is trying to fire up a disturbance along the front for Sunday, which means a possible chance of rain for the latter half of next weekend.

The Euro creates a stronger disturbance along the front and has the front waffle across the region on Saturday before the low pushes northeast through the Lakes, pulling the front north of us for a time before pushing back through as a cold front.  The model's been lagging on pulling the middle atmosphere trough into Eastern Canada and also tries to send some energy around the base of the trough in a more pronounced fashion than the GFS.  The GFS runs a much weaker system through just to our south (it's lacking that extra "kick" in the mid atmosphere that the Euro has), which paints some early morning rains across the Delmarva, Philly, and New Jersey but with just a singular frontal boundary passage.

The result for our forecast is a fair bit of uncertainty -- if the Euro is right we could be pretty mild on Sunday, if the GFS is right we will be struggling to get much above 60.  Saturday looks to be in comparable agreement as the front lies just south of us -- around 70, perhaps a notch milder south of the city.

Regardless of the uncertainty in Sunday's forecast, the weather early next week will be very Fall-like as the potential of the season's first frost in the Poconos looms on Monday morning and the threat of another morning in the 30's is not out of the question just to the city's north.  Our step down into the cold season continues...albeit slowly.