famartin Posted November 26, 2012 Share Posted November 26, 2012 New NAM went back to mostly snow at TTN (had been switching back and forth on the 12Z). Still just a bit too warm in the BL on the raw NAM soundings at NYC... that's the difference between being right under the heaviest band, and being either side of it by 20-30 miles. Still not buying the excessive NAM QPF. Maybe someone will get over a half inch but it won't be as widespread as the NAM shows. Link to comment Share on other sites More sharing options...
Zelocita Weather Posted November 26, 2012 Share Posted November 26, 2012 Wonder if we can pull off another Philly/SE PA Robbery like 11/7? I never mind being on the northern edge of the heaviest band 12-24 hours out... Link to comment Share on other sites More sharing options...
famartin Posted November 26, 2012 Share Posted November 26, 2012 Wonder if we can pull off another Philly/SE PA Robbery like 11/7? I never mind being on the northern edge of the heaviest band 12-24 hours out... Maybe this is revenge for 11/7, areas west of Philly get 6" while NYC gets a trace... Link to comment Share on other sites More sharing options...
Kaner587 Posted November 26, 2012 Share Posted November 26, 2012 Hi res nam looks juiced up Link to comment Share on other sites More sharing options...
earthlight Posted November 26, 2012 Share Posted November 26, 2012 I think we can easily find where the NAM has the best lift and a band of moderate precipitation to the NW of the developing surface low. This is definitely the best run yet for areas in SE PA/Central NJ and the Western NJ suburbs. Link to comment Share on other sites More sharing options...
Zelocita Weather Posted November 26, 2012 Share Posted November 26, 2012 Curious to see the snowfall output with the 18z NAM...I would think 2"+ would be more expansive to the north and east in NJ... Link to comment Share on other sites More sharing options...
forkyfork Posted November 26, 2012 Share Posted November 26, 2012 this run is colder than 12z and shows snow into the city now Link to comment Share on other sites More sharing options...
earthlight Posted November 26, 2012 Share Posted November 26, 2012 Link to comment Share on other sites More sharing options...
Dsnowx53 Posted November 26, 2012 Share Posted November 26, 2012 Is there really that much onshore flow that would keep areas just east of NYC that much warmer than areas just west of NYC? I really wouldn't be surprised if areas just east of NYC also got accumulating snows based on the 18z NAM output. This is much more elevation and precip rate dependent than proximity to the ocean, IMO. Not that the ocean will have no effect, but I don't see central NJ getting 6" and Queens and western LI getting 0. Link to comment Share on other sites More sharing options...
Ericjcrash Posted November 26, 2012 Share Posted November 26, 2012 Is there really that much onshore flow that would keep areas just east of NYC that much warmer than areas just west of NYC? I really wouldn't be surprised if areas just east of NYC also got accumulating snows based on the 18z NAM output. This is much more elevation and precip rate dependent than proximity to the ocean, IMO. Not that the ocean will have no effect, but I don't see central NJ getting 6" and Queens and western LI getting 0. Yeah, I just have a hard time believing anyone gets that much snow though, but the NAM seems to think so. Link to comment Share on other sites More sharing options...
ag3 Posted November 26, 2012 Share Posted November 26, 2012 RGEM appears to have a precip bump from its 12z run. Off the terrible black and white maps, I'm adding up 10-13mm. So about .50" into NYC. Similar to the NAM. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted November 26, 2012 Share Posted November 26, 2012 Yeah, I just have a hard time believing anyone gets that much snow though, but the NAM seems to think so. I don't think so either, but the confluent flow to the north will be able to provide a nice area of enhanced lift. The sharp cutoff represents this pretty well. Anyone that gets in on the mid level frontogenesis band may be able to pick up several inches. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted November 26, 2012 Share Posted November 26, 2012 Am nervous about those boundary layer temps. Latent heat absorption by melting snow might wipe out any surface-based warm layer, which could make this event mostly snow. Models mishandled this on 11/7, and I suspect they may be mishandling it with this upcoming event. I also don't see a strong onshore flow that would make Queens and even Long Island that much warmer than areas just west of NYC. It seems that lots of snowfall algorithms treat Long Island as a heat island even when there is a northerly flow or a very weak flow. Link to comment Share on other sites More sharing options...
famartin Posted November 26, 2012 Share Posted November 26, 2012 Is there really that much onshore flow that would keep areas just east of NYC that much warmer than areas just west of NYC? I really wouldn't be surprised if areas just east of NYC also got accumulating snows based on the 18z NAM output. This is much more elevation and precip rate dependent than proximity to the ocean, IMO. Not that the ocean will have no effect, but I don't see central NJ getting 6" and Queens and western LI getting 0. No, if the NAM output it to be believed, then they'd probably get close to the same, central NJ a little more. Link to comment Share on other sites More sharing options...
ag3 Posted November 26, 2012 Share Posted November 26, 2012 18z NAM total snow: Link to comment Share on other sites More sharing options...
earthlight Posted November 26, 2012 Share Posted November 26, 2012 0.60" snow over Central and NE NJ...pretty impressive. Link to comment Share on other sites More sharing options...
Zelocita Weather Posted November 26, 2012 Share Posted November 26, 2012 GFS coming in juicier and better presentation...0.25"+ throughout area Link to comment Share on other sites More sharing options...
Snow_Miser Posted November 26, 2012 Share Posted November 26, 2012 RGEM appears to have a precip bump from its 12z run. Off the terrible black and white maps, I'm adding up 10-13mm. So about .50" into NYC. Similar to the NAM. Are the precipitation types and thermal profiles similar to the nam as well? Link to comment Share on other sites More sharing options...
ag3 Posted November 26, 2012 Share Posted November 26, 2012 Are the precipitation types and thermal profiles similar to the nam as well? Total Precip: Link to comment Share on other sites More sharing options...
ag3 Posted November 26, 2012 Share Posted November 26, 2012 RGEM increased total precip but it lowered the total snow output. So 18z is warmer: Link to comment Share on other sites More sharing options...
Snow_Miser Posted November 26, 2012 Share Posted November 26, 2012 Thanks ag3. How much ice does the 18z rgem have? It's been showing a good bit of ice to start the storm. Link to comment Share on other sites More sharing options...
WeatherX Posted November 26, 2012 Share Posted November 26, 2012 RGEM increased total precip but it lowered the total snow output. So 18z is warmer: Did you happen to look at how much freezing rain the 18z accounts for in the total? Comparing this run to any of the previous runs today, it's a net increase in snow, verbatim. Link to comment Share on other sites More sharing options...
Sundog Posted November 26, 2012 Share Posted November 26, 2012 It's odd seeing precipitation types such freezing rain pop up on models. What we have is a boundary layer issue. The last thing we'll see is freezing rain. Link to comment Share on other sites More sharing options...
MJO812 Posted November 26, 2012 Share Posted November 26, 2012 Upton "IT SHOULD BE NOTED...IF THE PRECIPITATION IS HEAVIER THAN FORECAST...THE BOUNDARY LAYER WILL COOL...RESULTING IN HIGHER SNOWFALL AMOUNTS. IF THIS OCCURS...SNOWFALL ACROSS LONG ISLAND...NYC AND NORTHEAST NJ COULD SEE AMOUNTS BETWEEN A HALF AND 1.5 INCHES. CONFIDENCE IS TOO LOW TO INCLUDE THESE HIGHER NUMBERS IN THE AFTERNOON FORECAST." Link to comment Share on other sites More sharing options...
WeatherX Posted November 26, 2012 Share Posted November 26, 2012 It's odd seeing precipitation types such freezing rain pop up on models. What we have is a boundary layer issue. The last thing we'll see is freezing rain. That was my point. It's either snow, or rain-so, especially in the areas that models are hitting harder with snow, this is a bullish signal to perhaps get the higher amounts.... Link to comment Share on other sites More sharing options...
ORH_wxman Posted November 26, 2012 Share Posted November 26, 2012 It's odd seeing precipitation types such freezing rain pop up on models. What we have is a boundary layer issue. The last thing we'll see is freezing rain. Its impossible to see freezing rain without a warm layer aloft...or unless weak lift is centered well below the snow growth region...then you can have freezing drizzle, but that doesn't appear to be the case in this setup. The SREFs show no ZR or IP anywhere near NYC. Its either rain or snow. Link to comment Share on other sites More sharing options...
LongBeachSurfFreak Posted November 26, 2012 Share Posted November 26, 2012 Temps are going to drop like a rock now outside the city. Ideal radiational cooling conditions currently!! (They will probaly settle or rise slightly after the clouds move in later but some of the 's are going to get excited.) Link to comment Share on other sites More sharing options...
NJwinter23 Posted November 26, 2012 Share Posted November 26, 2012 This reminds me of last winter's january 19th storm..threading the needle in an otherwise hostile pattern with good enough timing...then the cold sank away into alaska/greenland like it is about to do, despite all of the blocking Link to comment Share on other sites More sharing options...
Isotherm Posted November 26, 2012 Share Posted November 26, 2012 This reminds me of last winter's january 19th storm..threading the needle in an otherwise hostile pattern with good enough timing...then the cold sank away into alaska/greenland like it is about to do, despite all of the blocking Last winter we had no luck threading any needles; this year we've already threaded two needles, Sandy, and the snowstorm a week later. If this autumn is any indication, we may be looking at winter that features more luck for us (though Sandy was not a thread the needle we wanted). Link to comment Share on other sites More sharing options...
NJwinter23 Posted November 26, 2012 Share Posted November 26, 2012 this is a rough map i put together real quickly...ive barely looked into this but i took the nam's heaviest precip axis into mind (while cutting those totals way back of course)....not bad considering I gave it virtually no chance for the coastal plain in this setup a week ago Link to comment Share on other sites More sharing options...
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