Kaner587 Posted March 22, 2013 Share Posted March 22, 2013 Expect 0z nam to drop 30 in on metro. Nam is useless Lol that wouldn't surprise me in the least Link to comment Share on other sites More sharing options...
jm1220 Posted March 22, 2013 Share Posted March 22, 2013 The Euro and ensembles are about 75% of what we should be factoring in at this range. The fact that they showed a NW trend from last run is important and a confidence booster. Link to comment Share on other sites More sharing options...
earthlight Posted March 22, 2013 Share Posted March 22, 2013 It's all going to come down to the incredibly frustrating upper level low/gyre north of New England. Several days ago when myself and a few others were talking about the potential for a sharp cutoff on the northern edge, we alluded to something similar to this occurring. These historically strong blocking episodes, and in this case historically negative AO for this time in the season, are notorious for producing events like this. In our case this time around, the gyre to the northeast of New England is very expansive and causes a very compressive circulation that is pressing down on the entire mid level height field. The 12z Euro trended much more favorable with this feature, but it still remains just a hair too overwhelming with the feature. We need to see this continue to shift northeast or become less aggressive. This is why we're seeing some models shunt the surface low off to the east -- it simply cannot advance farther north because it is being compressed by the poor wave spacing between the the vort max over the Mid Atlantic and the large upper level low to the north. These features are notoriously unpredictable and wreak havoc on forecast models in the medium range. So I wouldn't write anything off yet. Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 Gfs it's going to be a big here Link to comment Share on other sites More sharing options...
earthlight Posted March 22, 2013 Share Posted March 22, 2013 Through 54 hours the GFS is less compressed with the height field over New England..owing to the upper level low being farther north and the southern most vort in relation to that gyre being weaker. Nice illustration to compare the 12 and 18z runs drawing on the post above. Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 Over running hr 63 secondary is inside obx Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 Light to mod snow hr 66 Hr 69 994 east of Delmarva light - mod snow continues. Mod in snj Link to comment Share on other sites More sharing options...
earthlight Posted March 22, 2013 Share Posted March 22, 2013 That was a huge jump towards a less compressed height field..the surface low is tucked in off the NJ Coast now. It's just a hair disjointed with the vort max in the trough base though...I would bet money that the CCB goes just southeast of NYC this run. Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 Wow hr 72 992 low mod up to NYC heavy snow snj. Ccb brushing coast Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 Hr 75 988 easy of jersey show mod preciep back to nw jersey. Ccb just se of NYC like John said Link to comment Share on other sites More sharing options...
earthlight Posted March 22, 2013 Share Posted March 22, 2013 There are two vort maxes in the base of the trough at 72 hours that aren't completely phased and that allows things to escape a bit east. This run is another tick towards a huge solution. Link to comment Share on other sites More sharing options...
JSantanaNYC Posted March 22, 2013 Share Posted March 22, 2013 Every time we get a storm, the 18z run of the GFS is the one that shows the "OMG" solution first. Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 Hr 79 984 wow. Ccb just brushing NYC and jersey shore. Long Island into ccb Link to comment Share on other sites More sharing options...
earthlight Posted March 22, 2013 Share Posted March 22, 2013 I think every single person in this subforum will take this at 75 hours out though...it successfully transfers the mid level centers to the coastal low and the upper level height field orientation is much more favorable. http://www.meteo.psu.edu/~fxg1/AVNEAST_18z/f75.gif Link to comment Share on other sites More sharing options...
Allsnow Posted March 22, 2013 Share Posted March 22, 2013 .75 gets close to NYC this run Link to comment Share on other sites More sharing options...
RU848789 Posted March 22, 2013 Share Posted March 22, 2013 The Euro ensembles are def improved as well...better than 00z. The best thing about the Euro was that it was a marked improvement over the 00z run...and that is an important thing to see at this range. It is very close to showing a big solution...the ensembles don't necessarily add confidence to the fact that the big solution is coming..but it's good to see them improved. We are running short on time for the Euro to show another big bump to the NW. Usually after around 66-72 hours out whatever changes it makes will be small ticks and variations and nothing major. We need a good run tonight. Just curious if you or others saw the NWS-Philly discussion, where they said "...the latest 12Z Euro is indicating considerably more snow..." - are they referring to the ensembles and not the actual run? Just seems like an odd thing to say if several of the other models are showing more precip (unless they're showing more precip, but less snow, due to increased rainfall) than the Euro, as per what I can glean from this thread (although I'll admit I've only skimmed it). At the very least, having a shot at several inches of snow on 3/25 is pretty damn cool. .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... -- Changed Discussion -- THE MAIN FEATURE OF INTEREST FOR THE LONGER TERM IS THE STORM THAT IS FCST TO DEVELOP ALONG THE MID ATLANTIC COAST AND BRING WINTRY PRECIP TO THE AREA SUNDAY NIGHT THROUGH MONDAY. THIS EVENT IS STILL THREE DAYS AWAY AND THERE IS CONSIDERABLE UNCERTAINTY REGARDING QPF AND PRECIP TYPE. GUIDANCE GENLY AGREES THAT AN UPPER LOW WILL DEVELOP OVER THE CENTRAL US BY SUNDAY AND TRACK EWD TO CAUSE FAIRLY STRONG CYCLOGENESIS ALONG THE MID-ATLANTIC COAST ON MONDAY. DIFFS ARISE WRT TIMING, PRECIP AMOUNT AND TYPE. FOR QPF...WE ARE THINKING IN TERMS OF AROUND 0.5 INCH OVER DELMARVA AND SRN NJ...WITH .25 TO .33 OVER NRN NJ AND ADJ PA. HEAVIEST PRECIP SHOULD BE DURING THE DAY ON TUESDAY. PRECIP TYPE WAS BASED MAINLY ON LOW-LEVEL THICKNESS AND SREF P-TYPE PROBS... MOSTLY SNOW N AND W OF PHILLY...A RAIN/SNOW TRANSITION ZONE ROUGHLY ALONG THE NJ TURNPIKE CORRIDOR...AND MOSTLY RAIN OVER COASTAL SECTIONS OF SRN NJ AND DE. THE RAIN/SNOW WILL TEND TO SHIFT NWWD DURG THE DAY ON MONDAY AS LOW-LEVEL TEMPS RISE ABOVE FREEZING. NO SGFNT SLEET OR FREEZING RAIN IS EXPECTED WITH THIS EVENT. AT THIS TIME...SNOW AMOUNTS ARE EXPECTED TO BE IN THE 2 TO 4 INCH RANGE WELL N AND W OF PHILLY...1-2 INCHES LOWER DEL VLY...TO LITTLE OR NO ACCUM NEAR THE SHORE AND SRN DE. IT SHOULD BE NOTED THAT SOME GUIDANCE LIKE THE LATEST 12Z ECMWF IS INDICATING CONSIDERABLY MORE SNOW. http://forecast.weather.gov/product.php?site=NWS&issuedby=PHI&product=AFD&format=CI&version=1&glossary=0&highlight=off Link to comment Share on other sites More sharing options...
Dsnowx53 Posted March 22, 2013 Share Posted March 22, 2013 It's amazing how much more latitude this has been able to gain since other runs. As I have said before, over the past several days, we have made slow, gradual trends towards a ULL that is less compressive. At 54 hours, the wind barbs are W to E instead of WNW to ESE in Northern New England. We've also seen a more mature and organized area of vorticity with the main storm a bit to the west of previous runs, since the pattern has trended more amplified, and thus, slower. The storm does not race east and have a corresponding secondary low to the southeast...it's able to slow down, and have a secondary tucked in towards the coast and gain latitude. This is also why the timing of the storm has slowed down from Sunday night to a Monday and Monday night event. Link to comment Share on other sites More sharing options...
wkd Posted March 22, 2013 Share Posted March 22, 2013 Earthlight, thanks for your continued excellent analysis but was wondering what the gyre is you refer to? Link to comment Share on other sites More sharing options...
PB GFI Posted March 22, 2013 Share Posted March 22, 2013 I am not that shocked that ths is coming north my argument yeterday was the models were wrong w its strength of the confluence there is plenty of seperation and the error was north. I Looks like ths can start falling overnite sunday with a robust precip field and 850 s at minus 5 the surface should cooperate here There is some wiggle room here 3 days out but i really like the euro ensembles . As the confluence relaxes i thnk the snowfall is uniform around the area i dont see an unusually sharp gradient Link to comment Share on other sites More sharing options...
wkd Posted March 22, 2013 Share Posted March 22, 2013 Earthlight, thanks for your continued excellent analysis but was wondering what the gyre is you refer to? Never mind, I think you are talking about the close upper level low to the northeast. haven't heard it referred to this way by others. Link to comment Share on other sites More sharing options...
MJO812 Posted March 23, 2013 Share Posted March 23, 2013 21z SREFMuch wetter on this run for many areas Link to comment Share on other sites More sharing options...
Weather Fanatic 97 Posted March 23, 2013 Share Posted March 23, 2013 Nam looks way more impressive with that vort already through 33 Link to comment Share on other sites More sharing options...
Weather Fanatic 97 Posted March 23, 2013 Share Posted March 23, 2013 At hr 36 its already closed off! Link to comment Share on other sites More sharing options...
MJO812 Posted March 23, 2013 Share Posted March 23, 2013 SREF members Link to comment Share on other sites More sharing options...
RUNNAWAYICEBERG Posted March 23, 2013 Share Posted March 23, 2013 At hr 36 its already closed off! thats not necc a good thing. on the positive side, the pressing ULL is lifting into a more fav spot which will allow the redevelopment more room to gain latitude. Link to comment Share on other sites More sharing options...
Weather Fanatic 97 Posted March 23, 2013 Share Posted March 23, 2013 Wow many big big hits there Link to comment Share on other sites More sharing options...
RUNNAWAYICEBERG Posted March 23, 2013 Share Posted March 23, 2013 nam is off its rockers...its a massive hit for MO/IL with the initial low. the redevelopment looks good and starts to climb straight north. at h5, its very impressive looking. i love seeing the "boat": http://mag.ncep.noaa.gov/Image.php?model=nam&area=namer¶m=500_vort_ht&cycle=00ℑ=nam%2F00%2Fnam_namer_057_500_vort_ht.gif Link to comment Share on other sites More sharing options...
MJO812 Posted March 23, 2013 Share Posted March 23, 2013 Nam is going to end up much further west than 18z. It is actually phasing a piece of the ULL. Link to comment Share on other sites More sharing options...
Weather Fanatic 97 Posted March 23, 2013 Share Posted March 23, 2013 What a weird evolution! Link to comment Share on other sites More sharing options...
Kaner587 Posted March 23, 2013 Share Posted March 23, 2013 Nam is going to be a huge hit based in 60hr vv's. 63-69 should be heavy snow with Ccb overhead Link to comment Share on other sites More sharing options...
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