The Iceman

Ok lets throw out the current modeling because it “sucks” so let’s talk climatology since that’s basically Ralph’s main reason for not giving up hope since it’s “climatologically our snowiest month”. Of the top 25 largest Feb snowstorms that have occurred in Philadelphia history since 1950(since that’s all ENSO data goes back) how many of them occurred in a 2nd year moderate-borderline strong Nina? 0. What was the largest individual snowstorm in Philadelphia in those said years? 3.6”. All of those years were below normal average February in snowfall. Saying “oh feb isn’t over basically only because it is Feb. 3rd and it’s climatologically our snowiest month” is disingenuous without factoring in ENSO. Hey I like snow, hope we see a good threat come into the picture and that the models are wrong and the +PNA/-EPO stays around all month plus we get the transient blocking required for our huge snowstorms… but I don’t know why I’m getting sass for basically stating what historically happens in a 2nd year medium-strong Nina’s and the models now showing those very outcomes short and long term. Every threat will be “fragile” as Ralph says because we have no blocking. We know how “fragile” set up’s work 9 times out of 10 in these parts. It isn’t a close the blinds look because of the cold lurking nearby(for now), but it also isn’t an ideal pattern for warning level events by any stretch of the imagination and the pattern as currently modeled only degrades as we head into mid month which is typical of Nina climatology, especially in 2nd year Nina’s. As I said above, an advisory level event wouldn’t surprise me, but odds are against a warning level February snowstorm for the Philadelphia metro area and average monthly snowfall as it looks right now. Hopefully the models do a 180 and we see some blocking show up and I’m wrong and everyone ends up above average on the month. It’s a weather board meant for discussing long term prospects, sorry for sharing my opinion.

MJO heads out of the cod and into phase 4 by mid month, good luck getting snow with that. There aren’t any real true threats up through mid month on the ensembles with the AO and NAO firmly positive despite the cold air delivery source from the -EPO and western ridge. Anything that amplifies will cut west and anything weaker will be shunted and sheared out south. Maybe we get lucky and one of these shortwaves in the southern and northern streams time together just right like the tues/weds “threat” but Nina February’s are historically warm and snowless for a reason. Once we lose the western ridge as the MJO heads into phase 4, I expect we are above normal the 2nd half of the month. Maybe punt was the wrong word as I suppose we could score a surprise advisory level snow from a northern stream dominant system while we have the -EPO/+PNA but I do not see anything worth honking about right now and the pattern is only going to get worse as the month progresses. If you see a time frame that you like, feel free to shout it out, outside of maybe a flukey advisory level system, I don’t see diddly but cold and dry until the western ridge breaks down and temps warm up. We really needed at least transient AO/NAO help the first half of the month and right now I’m not seeing it. Give me some reasons to have hope Ralph.

For some reason I just have very little memory of that storm. 13-14 was one of my favorite winters in my lifetime too, there were so many events to track and we seemed to get lucky every time with them working out. But looking at the storm reports, we had a .25" of ice on top of likely a 6-10" snowpack, I can see how there were some issues.

Either need that northern vort to speed up so we can get it to phase or slow down to allow the southern stream to move further northwest via the SE ridge. It's all timing. Some blocking definitely would help in this situation but if the ridge out west can sharpen a bit, that can also do the trick. Still some time for things to improve on it, but I do think it's a long shot as a flush hit.

RIP snowpack fog really did a number on it overnight and I expect the rain and high temps to finish it off tonight besides the plow piles. Next couple weeks look uneventful, rain, snow, or otherwise. But at least it won't be stupid cold after this weekend. Looks seasonable next week, maybe slightly below normal but then 2nd half of the month is looking above normal as the SE ridge amps up. I think barring a surprise event in the next week, the rest of the month looks to be a punt. Hopefully we can get something in March with the shorter wavelengths to get some of us to around average snowfall(and get the N and W folks at least one decent event) but way too early to tell. Overall we could of done worse in a Nina down here. Feel for you Lehigh Valley/N and W guys though, this was the winter from hell up there.

I respectfully disagree. I really don’t think it will be that severe. Even the gfs now has temps in the upper 20s/low 30s during most freezing rain and I just don’t think it will accrete after temps being in the 40s overnight with plain rain. By the time temps get into the mid 20s which you really would need for accretion, it looks to change over to a period of sleet. I’m just not seeing it but will admit if I am wrong. Also storms over by noon up in the Lehigh valley so I don’t think Friday night is much of a concern. If anything it would be Friday morning. I think Monroe/Pocono region is more at risk for severe ice and they are currently under a watch.

18z NAM colder and more GFS like. Not quite as fast with the cold air arriving but definitely sped things up from 12z, however the intensity of the cold is still nothing like the GFS/Meso's. 3km NAM also not quite as cold. Also FWIW, the long range HRRR is very warm, basically all rain even up towards the lehigh valley. Pocono's though get a devastating ice storm on it.

NWS blend is not enthused with the icing potential really anywhere outside of NE PA:

Really 2 camps right now, you have the GFS/Meso Models bringing the cold air in faster and more dramatically(low to mid 20's as precip falls) vs CMC/Euro/NAM that are slower with the cold air and less intense(Upper 20's/low 30's). Who will come out on top? Those 2 solutions are vastly different outcomes wrt icing potential. I am leaning in the CMC/Euro/Nam camp right now.

Like if this comes to fruition, then there would be major icing concerns despite the daylight and warm temps leading into the changeover.

FWIW the meso model's are also in agreement with the GFS with some being even quicker to bring in the cold air right now. That's a bit concerning. They will be more useful at 00z though as most of them are at range right when they show the temp crash and tend to overdue the cold in these situations from what I remember in past events.

I mean look at the 12z NAM temps.. at 09z areas even up in the lehigh valley are still into the 40's Then as the "freezing rain" moves in, temps are still only 30-31 in the Lehigh Valley, that isn't going to accrete. Temps won't be into the mid 20's until the precip is just about over. Could the Lehigh Valley see a flash freeze? Maybe, but with it being during the daytime that would also be pretty unusual. I just do not see devastating ice storm in this set up for anywhere but NEPA into central PA. Untreated roads may be slick Friday morning in the Lehigh Valley but by Friday night, roads will have all been treated and mostly dried out. Philly and the Burbs, this is a purely rain event at this point. And FWIW the GFS isn't all that different, a tad colder so the "freezing rain" gets down into the Philly burbs but the same issues exist as the NAM.

Don't worry, he'll run off and start his own upstate NY/Central PA weather board soon enough if things aren't to his liking around here. Pretty funny to see him scurry back to AMWX though after he moved out of the Philly area.

Upon further glance, I think even most areas of Berks and Chester should be mostly ice free, maybe some slick spots up there but nothing devastating with power outage and tree damage. Now Central PA and the Pocono region is a much different story. That is where the biggest ice threat looks to be at the moment.

Roads are all still treated from the previous storm so there were no issues at least for me on the way into work and I take mostly all local roads, no highways. The walk to the car though was iffy, my walkway was very slick and my car was coated in ice.

Also Sunday’s storm is dead in the water, the Great Lakes low acts as a kicker. Northern stream way too fast again screws everything up.

I think the gfs is too cold. I’m not worried about ice at all down in the 95 corridor and even the surrounding burbs I think will be mostly ice free. Temps are going to hit 50. It’s going to have a hard time accreting even after temps fall below freezing. I think we at most see a coating of sleet at the end of the storm. Now areas n and w where temps will be closer to freezing during most of the precip, I’d be worried. Places like Lehigh Valley and out by Paul, I could definitely see a heavy ice event for you guys.

Euro was a big shift towards the GFS. Models converging on a solution or more shifts S possible? Pretty interesting set up.

The key is the strength of that high. Gfs has it at 1044 while the euro and nam are weaker with it at 1040(ecm) and 1038(nam) respectively. Strength of that high is going to determine the outcome of frozen. I’m impressed the GFS is holding serve but still skeptical. Btw those TT snow maps are trash, here are the pivotal which don’t show sleet as snow. Don’t want anyone thinking they have a shot of a foot out of this thing. Could be 2-4” of sleet though.

We have seen a tendency for the ECM to be too far NW in the last few weeks as I'm sure you painfully remember however, the GFS was too far SE in the previous system. The results ended up being somewhat in the middle of those 2 models and that's where I think we are headed again. Ice threat for the interior but mainly rain around 95 and the Philly metro area/NJ. But hey I'm just some random weenie that tries to forecast for fun. Won't be surprised if the 18z GFS trends a bit further N as none of the other globals budged at 12z. But who knows, maybe it scores the coup and most of us see some frozen out of this. I think I have more interest in the 2/7 time period for some frozen over a majority of the area though.

GFS on it's own right now though which is my one concern. CMC/UKMET both are too far north for everyone besides N and W and would be mostly rain for the philly metro area. GFS leading the way or is it overdoing the cold? How often do we see plain rain changing to freezing rain which is what the GFS depicts? You would think it would be more sleet than rain if the cold press is that strong.

Shades of 07 on that last GFS run. Would be 2 large sleet events back to back. However, there is still time to bring more snow into the equation especially N and W.

I’m disputing that 9” mark in lower makefield. I was over my siblings houses earlier who live there and there’s no way they saw more than we did.

Maybe Kuchera wasn’t bullshit after all…

Honking for what? flooding rains? But seriously, despite the big highs in place, it looks like we see the return of the big se ridge. Looks purely gradient driven so will depend if the cold air press can overcome the SE ridge. I see potential but it imo that set up favors rain for 95 with nw seeing frozen. Still time for things to change though.