Newman

The 18z Canadian suite (RGEM and CMC) bullish for snow Friday

I'll relay the message to Kyle! We appreciate the support at MU

Radar got sheared apart like all the mesos predicted just before it got here. Not even a flurry here while HBG, Lanco, and much of the central PA region saw accumulating snow

DeCaria is great, so is Dr. Sikora. But Dr. Clark especially is amazing, great funny guy and really challenges the students to do well. I took Meteorological Instrumentation with him this past semester, so much fun in that class building and installing some instruments around campus

From November 1st to today, December 20th, the Philadelphia area has only seen 0.82" of precip, Wilmington DE 1.19", and Trenton area 1.28"... all of which are record low amounts in this ~50 day stretch. New Brunswick NJ, Allentown, and Reading are close to record low amounts as well. It has been a really dry stretch to close out astronomical Autumn

I agree with the sentiments above that chances will increase as we head into the latter half of December and into the New Year. However, I would caution that our biggest risk in a -EPO, -PNA, west based -NAO pattern is cold and dry. Shortwaves will want to eject out of the SW and squeeze underneath the block. That typically lends credence towards weakening and shredding of the shortwaves. Or, if the block is too strong/west the systems will dive underneath us and whiff. Central PA is typically better off in these cases anyway compared to EPA or NYC/NJ... but it's still something to watch.

-EPO, west based -NAO means the risk is cold and dry not warm and wet as we head into the latter half of December and into January. -PNA means we eject systems and they squeeze underneath the block. If they aren't potent enough they'll get shredded apart.

I'd throw in the early December 2017 storm as well. Ended up with 6-8" in Berks

The PNA region looks to stay negative, so we'll definitely need those higher heights in the NAO region and high latitudes to force storms underneath the block. I like the look of the 50/50 region too, you'd build H across SE Canada. I just wonder if 1. Amplification of shortwaves could be obtained in a more zonal pattern and 2. If we'll have any semblance of a southern jet in this Nina regime

Mount Holly on tomorrow: I do think the overall environment will be highly favorable for a strongly forced and organized line of convection (likely a QLCS given the boundary orientation to the mean flow) along the cold front during the evening which may be capable of damaging winds and brief, weak tornadoes.

Who called my name

There is nothing in the next 2 to 3 weeks that would suggest we see snow, especially Philly SE but even NW burbs too. Ugly look for awhile

Take a look at the upper air differences between the GFS and Euro. That energy coming down from Manitoba is the 12/6 event we're tracking. But most importantly, look at the confluence and energy over the northeast at hour 144. Completely different look, and heights are a lot lower over the east on the Euro due to the confluence. This doesn't allow for heights to build in time and, verbatim, the Euro is a clipper redeveloper that crushes New England. In a fast Nina flow that we have, surprises and changes will be the common story. Lots of small mood flake events in this fast flow with some occasional nice surprises when things line up correctly Euro: GFS:

GFS with something for the 6th

Actually have a fine dusting on the cars and cold surfaces

Some small flurries occasionally here too

That's very surprising considering mping snow reports coming from Lebanon, Harrisburg, and Manheim. Still waiting to hear if it's snowing down in Lanco yet too

Looks like some mping snow reports coming in from York around Hanover and near Carlise too

Would love to hear some reports from y'all as the snow heads east, for anyone who will be awake to see it lol. Looks like the radar isn't as paltry as some of the short range guidance was suggesting

KU is Kocin-Ucellini... check out the "Northeast Snowstorms" book by them. We call historical snowstorms KU's sometimes

Something really interesting I wanted to share... the October 2021 averaged PDO index value came out to -2.55. In the entire PDO historical data set dating back to 1900, that's the most negative it's ever been since 1961. In fact, in the entire data set which takes monthly values, there's only ever been around 9 months across the past 121 years that have had a lower negative PDO value. That means 9 out of 1,450 months

I'd totally be down, however it would depend on the extensiveness of the details inside. A localized "KU" climatology book would be awesome, but if it's just surface details and doesn't get into the meat of each event I would pass.

Yes I am very much involved with the MU Weather Information Center forecasts and what not, but I did not have any say in what Kyle Elliott was doing with the winter forecast. His general reasoning, however, is 2nd year Nina's with the SST regime we're in are close in similarity to 2011-12 and 2017-18. The MJO will likely spend the most time as well in the unfavorable phases due to the SST pattern. The biggest wild card, as he mentioned in his bullet points, is the chance for high latitude blocking. The QBO is in a strong easterly (negative) phase right now which favors blocking. There's a lot to consider in a winter like the one coming up, I'm glad I don't have to release any official forecasts myself! I think a 22-27" snowfall winter is reasonable

12z Ukmet is a crusher for much of Philly east