Mitchell Gaines Posted March 5, 2013 Share Posted March 5, 2013 Quite a snowy run from the NAM. or . Link to comment Share on other sites More sharing options...
tombo82685 Posted March 5, 2013 Share Posted March 5, 2013 What does the mean for PHL, ILG, ACY look like if the three highest and three lowest QPF members are cast out? the sref plumes for 21z aren't out yet. Link to comment Share on other sites More sharing options...
famartin Posted March 5, 2013 Share Posted March 5, 2013 the sref plumes for 21z aren't out yet. NAM has 8-12 for TTN... Link to comment Share on other sites More sharing options...
tcutter Posted March 5, 2013 Share Posted March 5, 2013 NAM has 8-12 for TTN... so half that would be reasonable for the always over-amplified NAM (if it is correct)?? 4-6?? Link to comment Share on other sites More sharing options...
blizzardlover Posted March 5, 2013 Share Posted March 5, 2013 Quite a snowy run from the NAM. or . Yes.. I imagine there are a lot of veeeeeery interested folks in the Mt. Holly WFO waiting for the 0Z GFS to come out... C'mon, you know you want to issue watches..... Link to comment Share on other sites More sharing options...
tombo82685 Posted March 5, 2013 Share Posted March 5, 2013 sref plume for phl is 10, though i didn't take out the high ones and low. Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 The initial band, in the morning with the 700mb frontogen, will peak before it arrives to most of us. It is barely rain because of it from I-95 points SE. But as low level convergence increases around 21z, banding reforms and switches everyone over to snow. Solid 6-12" shot for most of the area. If the initial band were to hold on longer, we wouldn't switch to rain and the low levels wouldn't warm but the NAM/GFS continue to suggest this happens. Good news is that it happens during the daylight hours anyway. Precip isn't impressive anyway after the first surge and before the second one at 21z. Link to comment Share on other sites More sharing options...
chubbs Posted March 5, 2013 Share Posted March 5, 2013 NAM has 8-12 for TTN... Looks like much of the area is similar Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 awesome analysis HM, thanks for sharing this. What is your take on the gefs? I know they are starting to get maybe out of there usefulness. Do you believe the means accum qpf or could it be a fact of the lower resolution not picking up on the cycling you were talking about earlier? At this stage, I find the ensembles usually are lockstep with the operational unless something is really off. Their crappier resolution makes the GEFS useless in terms of banding, yes. Link to comment Share on other sites More sharing options...
Mitchell Gaines Posted March 5, 2013 Share Posted March 5, 2013 Yes.. I imagine there are a lot of veeeeeery interested folks in the Mt. Holly WFO waiting for the 0Z GFS to come out... C'mon, you know you want to issue watches..... We issued one for two counties this afternoon. Midnight shift will decide on that. Link to comment Share on other sites More sharing options...
blizzardlover Posted March 5, 2013 Share Posted March 5, 2013 We issued one for two counties this afternoon. Midnight shift will decide on that. Yes, you did -- was thinking of an expansion. Will make sense to get the Euro and GFS in... Thanks, Mitchell. Link to comment Share on other sites More sharing options...
chubbs Posted March 5, 2013 Share Posted March 5, 2013 According to the SREF ptype probs. Starts as snow in NE Md, N Del and roughly I95 N+W. R/S line advances NW to far northern suburbs or even beyond by 1 PM. Then shifts SE to I95 by 7PM and continues to shore in evening. This is just a broad brush and would vary depending on precip intenisty. As HM pointed out second wave would generate good snows. Link to comment Share on other sites More sharing options...
Mitchell Gaines Posted March 5, 2013 Share Posted March 5, 2013 sref plume for phl is 10, though i didn't take out the high ones and low. It's ticked up a bit. Biggest point from that run is the lowest member is now up to 2.5 inches. Link to comment Share on other sites More sharing options...
Birds~69 Posted March 5, 2013 Share Posted March 5, 2013 Ch6/Accuweather at 10 not really buying the "big" accumulation as of now: Link to comment Share on other sites More sharing options...
Mitchell Gaines Posted March 5, 2013 Share Posted March 5, 2013 Yes, you did -- was thinking of an expansion. Will make sense to get the Euro and GFS in... Thanks, Mitchell. yup any changes in products won't likely come till 4 am or so. Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 SREF/NAM are so close in the morning. There are decent probabilities for snow in NE MD / N DE / SE PA early morning on the SREF. A faster, more in tact, arrival of the h7 fronto band would mean more snow for everyone. Then we wait for round 2. Going to be an interesting GFS run! Link to comment Share on other sites More sharing options...
tombo82685 Posted March 5, 2013 Share Posted March 5, 2013 SREF/NAM are so close in the morning. There are decent probabilities for snow in NE MD / N DE / SE PA early morning on the SREF. A faster, more in tact, arrival of the h7 fronto band would mean more snow for everyone. Then we wait for round 2. Going to be an interesting GFS run! HM what causes the cycling and how can it be sped up so the shaft that appears on the gfs fills in. Does it have to do with the occlusion of the low? Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 HM what causes the cycling and how can it be sped up so the shaft that appears on the gfs fills in. Does it have to do with the occlusion of the low? You need something to sustain banding, just like thunderstorms, and the lift during the maturing/occluding low process can offset the secondary circulation. Once the system becomes vertically stacked, these features that sustain lift are no longer increasing in intensity and either gradually slacken off or weaken altogether. In this case, other features of the storm will begin to focus bands because there is still tremendous lift going on and it will be a gradual process. Link to comment Share on other sites More sharing options...
NJwinter23 Posted March 5, 2013 Share Posted March 5, 2013 Quick post here; I'll try to get back a little later... The ECMWF is slower than the GFS with the arrival of the 500mb low. But it isn't just that, it is also very slow as it wraps up, occludes and becomes vertically stacked. The aggregate here in deceleration allows the upstream northern s/w to become more of an influence. This added momentum + the blocking nudges this south off the Mid Atlantic Coast before resuming a NE motion. IF this is incorrect (it is likely overboard and the GFS is likely not enough), it is quite possible the comma head associated with the seaward ECMWF will adjust, once again, NW tonight. These subtle little changes in speed will make a huge difference in comma head placement. The process of vertically stacking is not something we see a whole lot near the VA/NC border, interacting with the warm Gulf Stream etc. It is very possible the models are not properly indicating the banding potential in our area. Any small timing differences in the V.S. process, mid-level low's arrival and next incoming northern stream s/w will make a huge difference for a tiny area. See y'all later I'm not sure if this is what played out in November, but the qpf output in that system was very poorly predicted, particularly the overnight stuff which just kept on going and going. All the models had the storm occluding fairly early and gave the appearance that the dynamics/precip would start dying out by late afternoon/evening...13" later in freehold NJ... Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 GFS does the EURO wobble south with upstream influence...best lift just stays offshore Wednesday evening/night. That could be the checkmate tonight. Link to comment Share on other sites More sharing options...
blizzardlover Posted March 5, 2013 Share Posted March 5, 2013 Not sure I follow... still showing solid QPF into the area, and if it's a little further east, won't it in fact be a bit colder? Do you think this a first sign of the GFS capitulating to the Euro? Link to comment Share on other sites More sharing options...
NJwinter23 Posted March 5, 2013 Share Posted March 5, 2013 Seems like they are meeting in the middle...still has 1" qpf for phl-nyc However, what HM is alluding to with the best lift shifting south of the area on the 00z gfs is a big deal due to the marginal temps. doesnt meen no snow, but we really need the big time lift to make this a meaningful accumulating snow Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 Yes, this is the GFS doing it finally (look closely at the pivoting/pendulum swing vort on southern end that whips the low into a wobble) but I think the ECMWF was still too extreme with it. They are meeting nicely... Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 Not sure I follow... still showing solid QPF into the area, and if it's a little further east, won't it in fact be a bit colder? Do you think this a first sign of the GFS capitulating to the Euro? I didn't mean to sound so gloom/doom but yes. See my original post about the euro's wobble. I said the GFS wasn't doing it enough and the ECMWF was likely too much. They will likely meet tonight reasonably. Link to comment Share on other sites More sharing options...
famartin Posted March 5, 2013 Share Posted March 5, 2013 GFS has 1-3" back home, verbatim... Guess the board should be working better now, compared to the crash it suffered after the NAM came out Link to comment Share on other sites More sharing options...
blizzardlover Posted March 5, 2013 Share Posted March 5, 2013 I didn't mean to sound so gloom/doom but yes. See my original post about the euro's wobble. I said the GFS wasn't doing it enough and the ECMWF was likely too much. They will likely meet tonight reasonably. Gotcha. Well, the Euro will be pretty fun to see roll in. Let's look at the trend though..we went from getting nothing a day or so ago to seeing the NAM and GFS hit us hard with 1"+ QPF and upward in spots. Great trend, and fun to have a legit threat to track this close to the event. Link to comment Share on other sites More sharing options...
famartin Posted March 5, 2013 Share Posted March 5, 2013 I'm not sure if this is what played out in November, but the qpf output in that system was very poorly predicted, particularly the overnight stuff which just kept on going and going. All the models had the storm occluding fairly early and gave the appearance that the dynamics/precip would start dying out by late afternoon/evening...13" later in freehold NJ... I recall that the best precip was more east than what the models showed, back in November. Placement of the CCB seemed to be in error. I verified in TTN only because they were squarely on the opposite side of the axis, Link to comment Share on other sites More sharing options...
NJwinter23 Posted March 5, 2013 Share Posted March 5, 2013 I didn't mean to sound so gloom/doom but yes. See my original post about the euro's wobble. I said the GFS wasn't doing it enough and the ECMWF was likely too much. They will likely meet tonight reasonably. Can we blow up the NAM? Please?? Link to comment Share on other sites More sharing options...
NJwinter23 Posted March 5, 2013 Share Posted March 5, 2013 I recall that the best precip was more east than what the models showed, back in November. Placement of the CCB seemed to be in error. I verified in TTN only because they were squarely on the opposite side of the axis, Yes true that was a big factor that I forgot about...but I also do recall the precip shield was much more expansive and longer lasting than the qpf forecasts would have led on. Outside of the 13" localized blow up in freehold..it was a pretty uniform 4-6" right up through where I am in Stamford CT on up to Worcester, MA Link to comment Share on other sites More sharing options...
HM Posted March 5, 2013 Share Posted March 5, 2013 I haven't really dived into the GFS, but it really kills the morning shot out this way. The QPF distribution is hilarious BTW. Between that and then the further east coastal track, snow amounts are not even half of the NAM. Oh well... lol Link to comment Share on other sites More sharing options...
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