NYC/PHL 12/21-12/22 Threat

[earthlight]

Recent operational mid range ensemble guidance continues to be indicative of a very past pacific low with a whole lot of energy coming east in response to the pacific jet. This, working in tandem with the blocking regime in place, will lead to the potential for some snow events in the medium range and keep us active coming off the gut-wrenching disappointment the last few days. Recent model runs have trended stronger with a northern stream shortwave that ejects eastward from the aforementioned upper level jet stream. What's interesting in the gradient pattern downstream. The confluence (which is lifting out a bit faster, ive noticed on some models lately; probably due to the further east and less amplified solutions with this weekends event) will do it's part to keep the cold air in place and allow this shortwave to scoot eastward. Any slower--and it could certainly suppress and "squash" this shortwave, which should happen to an extent anyway. What we're hoping for here is for it to happen less--in which case the moisture and precipitation could spread eastward and coat our grounds with light snow accumulation for the first time this season, aside from those who were lucky enough to see accumulation from the lake effect streamers. As a brief summary--not expecting anything major, but definitely noticing the potential for some light frozen precipitation..followed by what looks to be another potential threat around Christmas. That threat is way too far out to even garner any of my attention at this point. I included the 18z NAM H5 depiction below...should be noted that the 18z DGEX followed by bringing our area some light snow at 108 hrs. As a note of precaution..this threat could very well be dead within a few days given the rapid changes we have seen in this pattern on guidance thus far. But it's definitely worth at least checking out for now.

[Rtd208]

More like the NO NO NO storm potential lol.

im all for calling this thread the HO HO HO storm potential

[Chris L]

The Chrismas potential needs to be watched, however, I am sure we are a little bit weary conisering the quite bad model performance we had with the current storm. It is quite a convoluted pattern for the models to figure out. Do we want it to be simple, like when the Polar Jet justs digs to the Gulf and forms a shortwave trough, and amplifies and goes boom on the East Coast? That would be ideal; but the weather offers diverse setups all around; that's why we love it, non Mets and Meteorologists alike.

However, that said, the H500 map for the Christmas stom looks pretty nice on the ECMWF... Am I buying it? Not right now...

[earthlight]

The 84 hour NAM is much stronger with the shortwave over the Plains--and seems to have a much more potent upper level setup. But it retrogrades the surface low over the Gulf of Maine and the upper level cutoff low is going to create a problem in getting this storm far north and east. That being said--it's still a decent look for getting some light snow towards the area. The ridging is very pronounced ahead of the shortwave and, although the ULL is cutoff to our east, it is shifting north and east at a good clip and the confluence is rapidly lifting away from the area.

http://www.meteo.psu.edu/~gadomski/WRF_0z/f84.gif

[tmagan]

If anything, it makes for a nice Monday Night game, but I think this gets dampened and suppressed.

[Colin]

Good discussion as always. Any snow is good snow, so hopefully we can get something. After this latest disappointment, I'm not putting as much attention into any possible threat until it's about 12 hours out. We'll see what happens. Hopefully we can all get a coating.

[am19psu]

Recent operational mid range ensemble guidance continues to be indicative of a very past pacific low with a whole lot of energy coming east in response to the pacific jet. This, working in tandem with the blocking regime in place, will lead to the potential for some snow events in the medium range and keep us active coming off the gut-wrenching disappointment the last few days. Recent model runs have trended stronger with a northern stream shortwave that ejects eastward from the aforementioned upper level jet stream. What's interesting in the gradient pattern downstream. The confluence (which is lifting out a bit faster, ive noticed on some models lately; probably due to the further east and less amplified solutions with this weekends event) will do it's part to keep the cold air in place and allow this shortwave to scoot eastward. Any slower--and it could certainly suppress and "squash" this shortwave, which should happen to an extent anyway. What we're hoping for here is for it to happen less--in which case the moisture and precipitation could spread eastward and coat our grounds with light snow accumulation for the first time this season, aside from those who were lucky enough to see accumulation from the lake effect streamers. As a brief summary--not expecting anything major, but definitely noticing the potential for some light frozen precipitation..followed by what looks to be another potential threat around Christmas. That threat is way too far out to even garner any of my attention at this point. I included the 18z NAM H5 depiction below...should be noted that the 18z DGEX followed by bringing our area some light snow at 108 hrs. As a note of precaution..this threat could very well be dead within a few days given the rapid changes we have seen in this pattern on guidance thus far. But it's definitely worth at least checking out for now.

The 84 hour NAM is much stronger with the shortwave over the Plains--and seems to have a much more potent upper level setup. But it retrogrades the surface low over the Gulf of Maine and the upper level cutoff low is going to create a problem in getting this storm far north and east. That being said--it's still a decent look for getting some light snow towards the area. The ridging is very pronounced ahead of the shortwave and, although the ULL is cutoff to our east, it is shifting north and east at a good clip and the confluence is rapidly lifting away from the area.

http://www.meteo.psu.edu/~gadomski/WRF_0z/f84.gif

I merged the two threads, but want to make sure everyone sees earthlight's posts. He's on top of everything, as usual.

[tombo82685]

the 0z nam looks pretty interesting with that clipper,a lot further north than most guidance. We need that h5 vortex off sne to lift out more so.

[eduggs]

The 84 hour NAM is much stronger with the shortwave over the Plains--and seems to have a much more potent upper level setup. But it retrogrades the surface low over the Gulf of Maine and the upper level cutoff low is going to create a problem in getting this storm far north and east. That being said--it's still a decent look for getting some light snow towards the area. The ridging is very pronounced ahead of the shortwave and, although the ULL is cutoff to our east, it is shifting north and east at a good clip and the confluence is rapidly lifting away from the area.

http://www.meteo.psu.../WRF_0z/f84.gif

Nice summary. Trouble is the shortwave over the plains that looks so potent on the 84hr chart is embedded in the longwave ridge and moving toward the upstream side of the Atlantic trof/cutoff. That means it's almost certain to dampen until it is well into open waters. So we're left hoping for the low level lows to hold on long enough to deliver light overrunning snows as essentially the best case scenario (barring some huge changes). Some light powdery accumulations would be very nice, but even that seems relatively low confidence.

[Boreal]

Let's hope this thread ends with a better result than Talking Points.

By the way, this is a bland name. Suggest something better.

PHL/NYC In Search of 12/21--23 Potential

[A-L-E-X]

PHL/NYC In Search of 12/21--23 Potential

I think alliteration gets overplayed but.....

Suspense over a potential Solstice Slammer ?

[tombo82685]

for candy canes and choc chip cookies, here is the 21z sref's at hr 87

[am19psu]

PHL/NYC In Search of 12/21--23 Potential

I like this one best so far, but I'm sure we can do better

[SnowGoose69]

The 00Z NAM has a norlun signature at hour 42...its gone though by 48

[A-L-E-X]

hb for thread name, snow drought, but not as bad as boston

I like that name, has a nice ring to it.

[tombo82685]

I like that name, has a nice ring to it.

lol hahaha we could do the

snow drought, but not as bad as boston

[Isotherm]

lol hahaha we could do the

snow drought, but not as bad as boston

How about, "dec 21-23: if this threat is a no-go, we're gonna pull a midlo and make our own snow"

[am19psu]

lol hahaha we could do the

snow drought, but not as bad as boston

Easily the best one so far, but I don't want to stir up trouble with the other regions.

[tombo82685]

whats pretty crazy, we started that last thread sometime yesterday afternoon, within 24 hours we already had like 50,000 replies and almost 800 posts, impressive. If this was summer that would of taken the whole summer to achieve that.

[hudsonvalley21]

How bout " I'm STILL dreaming of a white Chritsmas" thread . Hopefuly we won't need part 2,3,etc.

[CooL]

wow i think i am desperate at this point. I am watching the GFS tonight to see what it does with the xmas storm

[Snowlover11]

Well hopefully with this next threat like you have said the outcome will be different. I like how its looking but so did the last threat a couple days ago.

[SnowGoose69]

wow i think i am desperate at this point. I am watching the GFS tonight to see what it does with the xmas storm

The first storm is going to give us the finger twice, first by missing us and then by basically shearing out the 2nd system.

[Collegestudent11]

The first storm is going to give us the finger twice, first by missing us and then by basically shearing out the 2nd system.

Well that cannot be good for snowlovers then.

[CooL]

The first storm is going to give us the finger twice, first by missing us and then by basically shearing out the 2nd system.

i hope you mean the clipper system lol im watching the storm after that already

[Isotherm]

The first storm is going to give us the finger twice, first by missing us and then by basically shearing out the 2nd system.

I'm not too ethused about it right now. With the amount of blocking we've got downstream, that may actually hurt our chances by keeping the newly formed H5 vortex positioned near/just NE of New England. Thus the W-E propagating Miller B clipper won't even have a fighting chance w/ that monster, vertically stacked low placed there. I can't look ahead as far as Christmas after experiencing this most recent defeat. After all, it's obvious the models will be highly erratic and essentially useless beyond 3-4 days in a convoluted regime of numerous small short waves ejecting ewd from the Pacific jet, extreme high latitude blocking, plus the backdrop of a strong la nina. So Iet's focus on the Tuesday clipper for now, which doesn't look that hot. But we've now got to root against the weekend system - hope that it's as weak/flat as possible, and consequently closes off further NE. More importantly, it needs to exit stage right or at least lift far enough NE so that the NLY confluence is no longer shielding our region from any type of precip.

[Collegestudent11]

The 0z is a bit closer, however, well out to sea.

DE would actually receive something measurable from this, a few inches.

[tmagan]

The 0z is a bit closer, however, well out to sea.

DE would actually receive something measurable from this, a few inches.

Maybe an inch in southern DE.

[Allsnow]

I'm not too ethused about it right now. With the amount of blocking we've got downstream, that may actually hurt our chances by keeping the newly formed H5 vortex positioned near/just NE of New England. Thus the W-E propagating Miller B clipper won't even have a fighting chance w/ that monster, vertically stacked low placed there. I can't look ahead as far as Christmas after experiencing this most recent defeat. After all, it's obvious the models will be highly erratic and essentially useless beyond 3-4 days in a convoluted regime of numerous small short waves ejecting ewd from the Pacific jet, extreme high latitude blocking, plus the backdrop of a strong la nina. So Iet's focus on the Tuesday clipper for now, which doesn't look that hot. But we've now got to root against the weekend system - hope that it's as weak/flat as possible, and consequently closes off further NE. More importantly, it needs to exit stage right or at least lift far enough NE so that the NLY confluence is no longer shielding our region from any type of precip.

I have been talking about that the last two days...we need this costal to move out and be weak....idk why analog96 was saying we need the storm to retrograde and help our clipper....that really makes little sense to me.....it would just dampen it out

[Absolute Humidity]

Congrats ocean city MD on your GFS inspired 1 - 2 inches.