The Cold was the Easy Part

This late week's forecast was challenging from the get-go.  But I was fairly certain the cold was coming.  And as shown below from the NWS, a freeze watch has been issued for our immediate area Thursday night into Friday morning.  This watch extends into northern MD as well.  See below...

With the passing of a weak low pressure system just south of PA on Thursday, cold air will advect south once the low passes our longitude and send cold air bleeding south into the Mid-Atlantic.  Most of the precip will be past, so snow will not really be an issue for the KMDT area.  However, in the northern and northeast part of the state, snow could accumulate a few inches, especially at elevation!  Here is the latest NAM's take on accumulated for Thursday's snowfall.

But the real interesting situation develops late Friday into Saturday.  The modeling is now coming into some sort of consensus, that being a storm, not as strong as originally modeled, and slightly off the coast a bit further.  BUT CLOSE ENOUGH TO AFFECT OUR WX SATURDAY.  The Japanese model is the most bullish for nasty snowfall for our region during Saturday into Sunday.  I believe this scenario is a bit overblown!  This would be a major snowstorm from downeast ME to around Philly!

The Euro is a bit flatter and further away from the coast, but still having an impact along the I-95 corridor...and possibly back to us here in Harrisburg!

Then the Japanese model spins up a doozy from the remnants of Rina which is currently spinning her way around the Gulf!  Look at this moisture laden system.  This solution does have some potential for the middle of next week!  Snow is not a concern with this as the thicknesses are much higher (warmer), but heavy rain would be a concern!

So as we march onto November, the atmosphere begins its countdown to winter and the cold weather season.  Had this pattern set up like this in December and January, my oh my, this would be rather intriguing!  But it is only October, and winter type precip is transient when it occurs.  But I do believe people will get a real dose of cold when Friday morning arrives and feel just how cold it became so quickly.  So I hope you enjoyed this last mild day for quite some time as the afternoon temps achieved 66F; it felt quite balmy at Landis Field.  But the cold air is ready to pounce and be in our area in spades beginning late Thursday and through the weekend.  Sunday will prove to be a nice day with a huge dome of high pressure over PA as shown below, but it will still have a bit of a bite to the air.

Speaking of bite, Happy Halloween y'all.  After all, Halloween has its origins not in ghosts or goblins, but as a cross quarter day, that being a day halfway between the Autumnal Equinox and the Winter Solstice!  All Saints Day falls close to the 4th Quarter Day of the Earth's Revolution cycle.  Halloween, a pagan celebration of All Hallow's Eve was recognized close to the 4th Quarter day of the annual solar cycle.  It still seems to be the most celebrated of the quarter days, although I'm partial of the celebration commemorating my buddy from Punxsutawney, PA, that being Groundhog's Day!

Enjoy your end of the week!

Smitty

AA:  Damp and raw Thursday with rain ending as the cold air arrives, then a cold Friday with the potential for some wintry type precip on Saturday.  Middle of next week, we could have a real soaker from the tropical disturbance down in the Gulf tonight.