Winter Storm for Tuesday (Big cities to be hit hard)

Final forecast call for the surprise snow:  Yes, surprise, because 24 hours ago there was no talk of this, but now we have snow coming. Here it is: 

Snow arriving around 8 am. Snow becoming moderate to heavy at times before ending by around 6 pm. Expect 4-5" of fluffy snow. It will be very cold with temps holding in the teens all day, and then dropping late. Low: 1 with gusty winds Wed morning. 

Rationale behind the complexity of forecasting snow amounts: 

1. Clipper system that is strengthening, as it goes to our south. This means that the snow will be light and fluffy. 
2. Deep moisture is not readily available until system is beginning to pull away meaning less snow. 
3. Arctic air will make for good snow making, and vertical motion lines up well with moisture meaning more snow. 
4. Arctic air is pushing and keeping system a little to far south to mean less snow. 
5. 4-6" in our area ... 6-8" Harrisburg ... 8-10 Lancaster ... 8-12" Philly. 
6. I must say that I expect to see 20:1 snow ratios but I have been too high for the most part on bigger systems this year, so ... I am dropping them to 15:1 which is still light. And getting 3/10 of an inch of melted precip would yield to 4.5" of snow. I guess we will see in another 30 hours. 

 


AT LEAST 4" SNOW COMING OUR WAY! MAYBE AS MUCH AS 8"! 


Remember that system I mentioned for Tues?  I said it would be too far SE ... wellllllll, my bad. Even though I adjusted closer (see comments below) than the models had and allowed from some very light snow ... I was not close enough. The major change started Sunday afternoon, I wanted to wait one my run of the models before I pulled the trigger. Well, gotta say we are going to have a winter storm. Now, areas to our south will get more snow ... surprise, surprise, a theme that has repeated itself this year every decent, widespread snowfall we've had this year. Lancaster could get 10" ... Philly: 12" ... Harrrisburg: 8" ... Selinsgrove: 3" ... 

My concern is that the storm could come further north, and as it gets stronger, the winds pick up, and with a dry fluffy snow, conditions get hazardous very fast. Right now snow should begin early tomorrow morning (7-8 am), and get heavy at times during the day, and then taper off a little after dark (5-7 pm). Expect a good 4" with the possibility of more. 

Another update early this afternoon.  

This the Canadian RGEM off their government site. It is leading the way for the bigger snow. This will be a very cold storm also. Fresh arctic air will be in place, for this system. This helps fluff the snow up, and make it dry, so it will blow around making travel tricky at best. Stay tuned for more later.

Not everyone will be happy, but some will: Winter is back. Not that this week has been a veritable heat wave, but it was rather pleasant for the most part. Not too cold, not too stormy. But that will be changing. At least as far as cold is concerned.

Arctic air will be entering the scene today, tomorrow and leave briefly for Monday as the big front drops from the north. Winds will be a factor Sunday and Monday. With that front comes some snow showers/squalls on Monday as well.

Tuesday –Friday will be cold. Highs will mostly be in the teens to near 20 and lows in the single digits to near 10. This is a good 15 degrees below average!  And this is the coldest time of the year for our area. So this is some good old fashioned winter cold.

What about snow?  Not much, but I am watching two systems: one for Tuesday and one for Thursday. Tuesdays I feel will be too far to the SE and off shore. It is possible for it to end up close enough that we get a little light snow. But probably not much if anything. 


Thursdays system is more interesting. I will be an arctic wave (similar to our storm earlier this month). It will strengthen as it moves off the coast and out to sea. How strong it is will be key to how much moisture it can wring out of the atmosphere. This would be a dry fluffy snow, so it won’t take a lot of precipitation to give a decent snow.  


The only other weather maker will be over the next weekend, especially towards later Sat-early Sunday. Not a big system, just some light snows ahead and along a cold front.

This cold weather should lock in for at least the next 10 days, and probably longer. It won’t be super cold all the time, but a week like this last week is not foreseen in the next two weeks at least. The west coast will stay dry for the most part, but a system could bring some needed, but scattered, rain/snow to them by next weekend.  

Specifics:

Sunday: Windy with more clouds than sunshine. High: 34. low: 19.

Monday: Sunshine with increasing clouds, windy. Snow showers/squall possible late. Much colder at night. High: 38 Low: 17.

Tuesday: Partly to mostly sunny and cold. Gusty winds. High: 21. Low: 2.

Wednesday: Partly to mostly sunny and cold. High: 18 Low: 7.

Thursday: Becoming cloudy, still cold. Snow is possible. High: 18. Low: 13.

Friday: Windy and cold. Sunshine and clouds. High: 20. Low: 8.

Saturday: Cold with lots of sun and late clouds. Some light snow possible at night. High: 30. Low: 20.

Sunday: Chilly and windy. Sun and clouds. High: 35. Low: 15.