Newman

Correct going into 09-10 the QBO was in a rather strong easterly regime which bodes well for the high latitude regions. This year we will likely be transitioning from westerly to easterly. I saw a tweet that said the most probable and similar QBO analog year is 1995-96. Keep in mind last year's QBO transitioned easterly to westerly, this year will be the opposite.

The current look, featuring cooling in the east based regions of the ENSO with western regions remaining warmer. The PDO is positive with a warm pool south of Alaska, but not to the extent of 2013-14 obviously. A cold pool east of Newfoundland in the Atlantic with warm waters immediately south of Greenland.

Thanks to some help from another forum, I found the 2003-04 winter and it looks like a semi-decent analog right now. We were coming off a prior El Nino winter, ENSO turned weak Nino/Neutral for the winter, Positive PDO, Positive AMO, and there was low solar activity. I expect all of the same for this upcoming winter. However, the summer of 2003 transitioned into a neutral phase much quicker than what is currently forecasted for this summer/fall/winter. I would throw in 2004-05 in case we remain more El Nino, rather than completely neutral. I like 2004's QBO transition into winter as well. It's much better than 2003 and it's close to what I think we could see this winter. A later transition of the QBO could yield later stratospheric impacts deep into winter (February and March, but things like that are fickle and require other variables to look at). 2004-05 also had a warm Atlantic and low solar, but not as warm of a Pacific. 1966-67 is a solid analog with regards to the positive ONI values maintaining closer toward fall/winter. And in case we go more Nina/neutral, it's even greater. I thought about 1959-60 as well. That winter was very very similar to 2003-04 with a transition to neutral much quicker than what is expected this year. It was coming off a weaker El Nino, +AMO, +PDO, low-ish solar activity. But again, the QBO went easterly to westerly during the winter. I like a 2003/1959 winter looking at a warm Atlantic, a fairly warm Pacific, weak El Nino/Neutral ENSO, lower solar, and then throw in a similar QBO progression seen entering the 2004-05 winter with a switch from westerly to easterly and a later transition from weak El Nino to neutral conditions seen in 1966-67 and you have something like this: Obviously, be aware there is more to a winter than just the variables I pointed out. AAM tendencies, the NAO background state, etc. all are important variables among others. Last year we got killed with a Pacific that would not slow down. We'll see how the Pacific cooperates this year. A lousy Pacific is always more concerning over a lousy Atlantic pattern. I'm excited for fall and the introduction of winter to see what we got on our hands this year.

I've just started to look towards what this winter may deliver, and 2003-04 seems like a strong analog. It was coming off a prior El Nino winter, it was mainly weak Nino/Neutral during the winter, it had a positive PDO, positive AMO, and low solar activity. However, the summer of 2003 transitioned into a neutral phase much quicker than what is currently forecasted for this summer/fall/winter. I would throw in 2004-05 in case we remain more El Nino, rather than completely neutral. I like 2004's QBO transition into winter as well. It's much better than 2003 and it's close to what I think we could see this winter. A later transition of the QBO could yield later stratospheric impacts deep into winter (February and March, but things like that are fickle and require other variables to look at). 2004-05 also had a warm Atlantic and low solar, but not as warm of a Pacific. 1966-67 is a solid analog with regards to the positive ONI values maintaining closer toward fall/winter. And in case we go more Nina/neutral, it's even greater. That's what I see right now at least.

The hail threat today across PA is not going to be one to overlook! Already a storm warned for baseball sized hail: Destructive, baseball-size hail and wind gusts to 70 mph.

Really the only wild card seems to be how well we recover from this morning rain and cloud cover for todays severe threat. Mount Holly continues to become more and more concerned on their 8am update: Additionally, given the fairly quick movement of the line of showers/storms, concern continues to increase that the post-storm environment will quickly recover/destabilize to support a potentially significant severe threat this afternoon/evening, especially south of I-78.

The cell passing through Johnstown and the other one SW of State College look dangerous. Definitely rotation on both and both look like supercells. Heads up Central PA folk.

HRRR agrees with the WWA issued as well.

WWA across SE PA for 2-4". 18z NAM agrees.

Euro:

12k NAM Kuchera, which I think is more reliable in this case with the warmth aloft.

I think the I-95 area will battle sleet and rain for the most part, although it's close. There's clearly a warm layer up top. For those 30 miles or so NW of Philly, it's going to likely be a wet isothermal bomb. However, if the I-95 area can cool the column enough, they could easily see a wet paste job. Temps are very marginal and it'll come down to snow rates and dynamic cooling aloft.

Could Someone explain why Greenland ice is at a record level with regards to surface mass balance? If there is any sign for this to decrease and get back to normal levels, what is it?