nzucker Posted December 23, 2012 Share Posted December 23, 2012 The 850 line on the NAM barely reaches Cape May, NJ. With a weak low and limited WAA, that's got to be snow. Link to comment Share on other sites More sharing options...
KEITH L.I Posted December 23, 2012 Share Posted December 23, 2012 The 850 line on the NAM barely reaches Cape May, NJ. With a weak low and limited WAA, that's got to be snow. there is a problem with 920 temps i think..whatever lol Link to comment Share on other sites More sharing options...
nzucker Posted December 23, 2012 Share Posted December 23, 2012 there is a problem with 920 temps i think..whatever lol Here is the NAM sounding for HPN (White Plains) at 36 hours: The freezing depth is around 975mb. That should be cold enough for snow given that 850s are around -2C. It warms after that though, so we might change over. You are also at a bigger risk than I being on Long Island where the boundary layer warming is stronger. For Central Westchester, however, this is a snow sounding. Link to comment Share on other sites More sharing options...
Isotherm Posted December 23, 2012 Share Posted December 23, 2012 Definitely begins as a couple hours of snow on the NAM for NYC. Around 9pm-11pm, then looks like it changes to mix/light rain by 06z. However, surface winds are now depicted NELY throughout the event so I'm wondering if the NAM is a bit too torchy in the lowest 50-100mb. Still have 24-36 hours to sort this out. NYC at 03z XMAS Eve: Link to comment Share on other sites More sharing options...
WeatherFox Posted December 23, 2012 Author Share Posted December 23, 2012 Definitely begins as a couple hours of snow on the NAM for NYC. Around 9pm-11pm, then looks like it changes to mix/light rain by 06z. However, surface winds are now depicted NELY throughout the event so I'm wondering if the NAM is a bit too torchy in the lowest 50-100mb. Still have 24-36 hours to sort this out. NYC at 03z XMAS Eve: This is a nail bitter of a forecast. NWS has gone back and forth with some snow versus no snow. Accu-Weather has been forecasting a mix. If we verify, Snow88 will be happy to at least see some snow falling and if we are lucky we could get a quick and brief inch on the grass . Link to comment Share on other sites More sharing options...
WintersGrasp Posted December 23, 2012 Share Posted December 23, 2012 This is a nail bitter of a forecast. NWS has gone back and forth with some snow versus no snow. Accu-Weather has been forecasting a mix. If we verify, Snow88 will be happy to at least see some snow falling and if we are lucky we could get a quick and brief inch on the grass . Yep...tough forecast but I think it is a bigger deal for the majority due to the timing and the idea of "snow on Christmas Eve/Christmas"....otherwise it's the difference between no snow and maybe a coating on grassy surfaces....not any sort of danger to driving or travel which is the usual concern and basis of the NWS and any local weather center's forecasts Link to comment Share on other sites More sharing options...
WintersGrasp Posted December 23, 2012 Share Posted December 23, 2012 Though I will say....I do think that there IS about 90% chance that those in the NW suburbs of NYC have a coating early Christmas morning and still a 70% chance that us within miles of the city do as well .....it's not the few inches that we thought possible just a day ago but it's flakes on Christmas nonetheless Link to comment Share on other sites More sharing options...
MJO812 Posted December 24, 2012 Share Posted December 24, 2012 0z Nam has the low going right under NYC. Looks like snow everywhere and snow and rain near the coast but no accumulations near the coast. Link to comment Share on other sites More sharing options...
isnice Posted December 24, 2012 Share Posted December 24, 2012 0z Nam has the low going right under NYC. Looks like snow everywhere and snow and rain near the coast but no accumulations near the coast. It's probably rain or sleet. It's not just warm at the surface, it's warm all the way up to 900mb. Link to comment Share on other sites More sharing options...
denvillenj Posted December 24, 2012 Share Posted December 24, 2012 hows mmu look for tomorrow night? Link to comment Share on other sites More sharing options...
MJO812 Posted December 24, 2012 Share Posted December 24, 2012 It's probably rain or sleet. It's not just warm at the surface, it's warm all the way up to 900mb. Which is weird because the low goes beneath us. Remember when the models showed really cold air with this little system? Link to comment Share on other sites More sharing options...
rgwp96 Posted December 24, 2012 Share Posted December 24, 2012 hows mmu look for tomorrow night? if nam is right where u are in denvile would probably have 1-2 inches of snow and a little sleet mixed in Link to comment Share on other sites More sharing options...
brenjames Posted December 24, 2012 Share Posted December 24, 2012 The first thousand feet is warm rain or sleet at close look. Link to comment Share on other sites More sharing options...
denvillenj Posted December 24, 2012 Share Posted December 24, 2012 rgwp i'm just north of rt 80 700 ft... hope we can get something on the ground for christmas morning Link to comment Share on other sites More sharing options...
MJO812 Posted December 24, 2012 Share Posted December 24, 2012 What? lol NYC Sanitation department "DSNY issues snow alert for Mon. 12/24 at 4 pm for chance of slushy coating. Salt spreaders are loaded. " Link to comment Share on other sites More sharing options...
eduggs Posted December 24, 2012 Share Posted December 24, 2012 It's probably rain or sleet. It's not just warm at the surface, it's warm all the way up to 900mb. Based on the 0z NAM soundings, I'm seeing snow to rain along the immediate coast. Mostly snow at KNYC. And all snow just N&W. Surface temps near the City rise just above freezing, but there are no really warm layers in the column. Temperatures should rise above freezing during the day almost everywhere after the precipitation stops. It's probably a good idea to go with half the NAM QPF at this point as a preliminary forecast. So we're looking at roughly a tenth of an inch liquid. If we're lucky some people will officially get a white Christmas! Link to comment Share on other sites More sharing options...
Isotherm Posted December 24, 2012 Share Posted December 24, 2012 Based on the 0z NAM soundings, I'm seeing snow to rain along the immediate coast. Mostly snow at KNYC. And all snow just N&W. Surface temps near the City rise just above freezing, but there are no really warm layers in the column. Temperatures should rise above freezing during the day almost everywhere after the precipitation stops. It's probably a good idea to go with half the NAM QPF at this point as a preliminary forecast. So we're looking at roughly a tenth of an inch liquid. If we're lucky some people will officially get a white Christmas! Yeah I agree based on the 00z NAM. I also noticed that latest NAM runs have introduced more of a NELY component at the surface rather than the SELY winds it depicted earlier today. This is a major reason why the lower boundary layer is quite a bit cooler for NYC; the primary dampens out and we even try to get a very weak sfc low just south of the area. If precip intensity can become moderate Christmas Eve, I think there's a good chance we'll have a few hours of snow sticking to grassy surfaces, pretty much areawide. It would be enough for official white Christmas assuming it doesn't get washed away overnight. Link to comment Share on other sites More sharing options...
isnice Posted December 24, 2012 Share Posted December 24, 2012 00z NAM surface parameters for KNYC. Rain... http://68.226.77.253/text/NAMSFC/NAM_KNYC.txt Link to comment Share on other sites More sharing options...
Snow_Miser Posted December 24, 2012 Share Posted December 24, 2012 The 00 rgem was a pretty decent little event NW of I-95. About 4-6 hours of snow for most parts. Link to comment Share on other sites More sharing options...
Allsnow Posted December 24, 2012 Share Posted December 24, 2012 Going to be nice to see snow tonight. Link to comment Share on other sites More sharing options...
PB GFI Posted December 24, 2012 Share Posted December 24, 2012 00z NAM surface parameters for KNYC. Rain... http://68.226.77.253/text/NAMSFC/NAM_KNYC.txt Check out hrs 27-33 850s minus 2 surf 36 not a lock that city doesnt see at least a lil snow Link to comment Share on other sites More sharing options...
isnice Posted December 24, 2012 Share Posted December 24, 2012 12z NAM looks a little better for areas north and west of the city. Could see some wet flakes falling later this evening. Link to comment Share on other sites More sharing options...
TWCCraig Posted December 24, 2012 Share Posted December 24, 2012 I'm not sure what to expect here on the south shore of LI. Most likely will start out as snow, but may change to rain late. Based of the 12z NAM, I don't think surface temps are the problem, the problems are the 925mb temps and the 850's, they go above freezing as the night progresses which will definitely cause a change over to rain. Link to comment Share on other sites More sharing options...
eduggs Posted December 24, 2012 Share Posted December 24, 2012 I'm not sure what to expect here on the south shore of LI. Most likely will start out as snow, but may change to rain late. Based of the 12z NAM, I don't think surface temps are the problem, the problems are the 925mb temps and the 850's, they go above freezing as the night progresses which will definitely cause a change over to rain. Yeah the GFS and NAM have both increased low level warming. There could still be some mood flakes near the coast but accumulations south of I-287 or so look less likely. Looking at obs from around the region, the airmass is marginal. A burst of precip at the onset could lay down at least a coating. We'll see. Link to comment Share on other sites More sharing options...
Quincy Posted December 24, 2012 Share Posted December 24, 2012 This might be one of those events where NYC is all rain, but if any heavier bursts of precipitation move in, it flips back and forth between wet snow/rain. Link to comment Share on other sites More sharing options...
SnoSki14 Posted December 24, 2012 Share Posted December 24, 2012 Let's just be real here, how much QPF are we talking here, maybe .10-.20, so whether it's rain or snow, it's very little either way. Maybe a dusting to an inch at best for some, but that's about it. If it wasn't for Christmas, none of us would even bother with this so called storm. Link to comment Share on other sites More sharing options...
isnice Posted December 24, 2012 Share Posted December 24, 2012 Snowing in some areas of Virginia and D.C. where none was expected. If nothing else, it's a promising sign for flakes this afternoon. Link to comment Share on other sites More sharing options...
TWCCraig Posted December 24, 2012 Share Posted December 24, 2012 Snowing in some areas of Virginia and D.C. where none was expected. If nothing else, it's a promising sign for flakes this afternoon. Yeah, snowing at Washington/Dulles airport right now, though that's not near the center of D.C. Only rain/sleet was forecast for there. Link to comment Share on other sites More sharing options...
Zelocita Weather Posted December 24, 2012 Share Posted December 24, 2012 Air mass is mid to upper 30s near highs for day and dews around 20...it'll snow.... Link to comment Share on other sites More sharing options...
isnice Posted December 24, 2012 Share Posted December 24, 2012 Air mass is mid to upper 30s near highs for day and dews around 20...it'll snow.... I agree. For how long is the question. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.