tmagan Posted February 28, 2015 Share Posted February 28, 2015 12Z RGEM ensemble meteogram for KNYC. Link to comment Share on other sites More sharing options...
weatherpruf Posted February 28, 2015 Share Posted February 28, 2015 jm - perhaps you have your storms confused (I know I have a hard time keeping track of them, since there have been so many and so many similar ones this winter), as the 2/21 storm delivered a solid 4-8" for just about all of SE PA/South Jersey (except Cape May/Atlantic Counties) and a solid 3-6" for the rest of NJ north of 195. In the New Brunswick-Edison area, we got about 4" of snow and then about 0.2" of ZR on top of that with temps only getting to 33F after about 1 am, much later than expected. Would love to get a repeat of that much frozen precip. http://climate.rutgers.edu/stateclim/?section=menu&target=wint1415snowtotals#2/21-2/22/15 How many inches you sitting on for this year, and what are your thoughts for this storm? Link to comment Share on other sites More sharing options...
Guest Pamela Posted February 28, 2015 Share Posted February 28, 2015 touché This is OT but did you hear about a group of people debating to walk from LI to CT over the sound? There is a forum thread dedicated to this on some website I was reading. Not sure if it has ever been done before? No...but I *did* stay at a Holiday Inn Express last night!.... Here's a good article on the state of affairs between our states: http://suffolktimes.timesreview.com/2015/02/56449/with-icy-air-comes-a-frozen-long-island-sound/ Link to comment Share on other sites More sharing options...
RU848789 Posted February 28, 2015 Share Posted February 28, 2015 So, if 925's are above freazing and the entire column below is freazing or colder, you get sleet? I'm used to paying attention to 850's and below. Thanks for the schooling. There's no absolute rule on freezing rain vs. sleet, which is why both are so hard to predict. That's because the phase transitions from snow to rain and then from rain back to either sleet or freezing rain are far more complex that just knowing the temperatures at two different pressures (heights above ground, really) in the column. For example, the phase change for a given snowflake of a given mass to melt to become a raindrop of presumably the same mass requires a sum total of heat imparted from the atmosphere, so in order to truly do the calculation, one would need to know the actual continuous temperature profile of the entire column (for the above freezing part where melting is occurring), as well as how long that snowflake resided in each section of the column. Same thing for the raindrop, which maybe melts at the ~850 mb level, i.e., one would need to know the continuous temperature profile below that (for the below freezing part) and the time spent in each section of the column at each temp in order to calculate whether the raindrop would refreeze into a sleetdrop before reaching the surface. I assume the models are actually calculating those things on some at least approximate basis (probably taking "slices" of the column every X feet and doing the heat balance over time calcs for each column slice, e.g., the "soundings" of conditions at each slice), and not just assuming one temp at 850 and another at 925 and a third at the surface and doing the heat balance just for those fairly deep slices in the column. Sure, there are rules of thumb, such as if the temp is above freezing for a few thousand feet in the vicinity of 850 mb, the snow will melt and if the column goes back below freezing for several thousand feet below that (i.e., goes below freezing well above the 925 mb elevation), then, yes, the melted snowflakes will refreeze into sleet...or if the column doesn't go back below freezing until 925 mb or even lower, i.e., if only the last few hundred feet of the column down to the surface are below 32F, then the melted snowflake will not freeze into sleet while falling, but the water droplet will likely cool to 32F or below (supercooling is possible) and will then freeze on contact with the below 32F surface it strikes. All of the above is just a really long way of saying that there will be times when 850 mb is above freezing and 925 mb and below is below freezing and the result is sleet and there will be times when the result is freezing rain. Depends on the actual continuous temperature profile of the entire column below where the snowflake melts. Link to comment Share on other sites More sharing options...
tim Posted February 28, 2015 Share Posted February 28, 2015 the gfs keeps getting drier ...my barometric readings are sky high..'banjo' style barometer almost reading 31.00 inches ..digital one says 1045mb..strong high pressure in place. Link to comment Share on other sites More sharing options...
RU848789 Posted February 28, 2015 Share Posted February 28, 2015 How many inches you sitting on for this year, and what are your thoughts for this storm? 34" in Metuchen this winter, which is likely about 4-5" more than most others would have measured, since I'm a nut about measuring at the exact end of the snowfall, regardless of whether it's 7 pm or 4 am, which will result in 1/2" to 1" greater snowfall in a snow to sleet/ZR/rain scenario vs. measuring 1-2 hours after the changeover (after compaction occurs) and that's happened at least 3-4 times this winter. In addition, the two very high snow/liquid ratio storms compacted quite quickly after sunrise, so getting those measurements at the end of the snowfall made a difference. Anyway, I'm not a forecaster, so I don't make predictions, per se. Like any other non-pro, I have a gut instinct and I can read the model output, so I'd say 2-4" for NYC and close by suburbs in NE NJ, LI seems like a good bet right now. I'm hoping I'm far enough north (25 miles SW of Central Park) to be part of that 2-4" swath (on the low side, of course) in Central Jersey, but I can see that dwindling down to an inch or less by the time one reaches 195; alternatively areas north of I-80 in NJ (west of 287) and north of 287 in the Hudson Valley may see 4-7" of snow. Some sleet and freezing rain are a definite concern, too, especially south of the 80/287 region, where it's more likely to stay all snow. Anyone who reads my post from a few minutes ago on sleet vs. freezing rain would know I would never presume to try to predict either of those, given the complexity. Link to comment Share on other sites More sharing options...
Metasequoia Posted February 28, 2015 Share Posted February 28, 2015 There's no absolute rule on freezing rain vs. sleet, which is why both are so hard to predict. That's because the phase transitions from snow to rain and then from rain back to either sleet or freezing rain are far more complex that just knowing the temperatures at two different pressures (heights above ground, really) in the column. For example, the phase change for a given snowflake of a given mass to melt to become a raindrop of presumably the same mass requires a sum total of heat imparted from the atmosphere, so in order to truly do the calculation, one would need to know the actual continuous temperature profile of the entire column (for the above freezing part where melting is occurring), as well as how long that snowflake resided in each section of the column. Same thing for the raindrop, which maybe melts at the ~850 mb level, i.e., one would need to know the continuous temperature profile below that (for the below freezing part) and the time spent in each section of the column at each temp in order to calculate whether the raindrop would refreeze into a sleetdrop before reaching the surface. I assume the models are actually calculating those things on some at least approximate basis (probably taking "slices" of the column every X feet and doing the heat balance over time calcs for each column slice, e.g., the "soundings" of conditions at each slice), and not just assuming one temp at 850 and another at 925 and a third at the surface and doing the heat balance just for those fairly deep slices in the column. Sure, there are rules of thumb, such as if the temp is above freezing for a few thousand feet in the vicinity of 850 mb, the snow will melt and if the column goes back below freezing for several thousand feet below that (i.e., goes below freezing well above the 925 mb elevation), then, yes, the melted snowflakes will refreeze into sleet...or if the column doesn't go back below freezing until 925 mb or even lower, i.e., if only the last few hundred feet of the column down to the surface are below 32F, then the melted snowflake will not freeze into sleet while falling, but the water droplet will likely cool to 32F or below (supercooling is possible) and will then freeze on contact with the below 32F surface it strikes. All of the above is just a really long way of saying that there will be times when 850 mb is above freezing and 925 mb and below is below freezing and the result is sleet and there will be times when the result is freezing rain. Depends on the actual continuous temperature profile of the entire column below where the snowflake melts. Very thorough and complex. Thanks. I'll just let the professionals figure out p-type. Link to comment Share on other sites More sharing options...
NorthShoreWx Posted February 28, 2015 Share Posted February 28, 2015 North shore of Long Island is its own micro climate. The bluffs really insulate it, and the sound, especially this time of year, does nothing to warm it up. I've seen many times where the LIE is the dividing line between sn+ and rn/ip. I remember in the February 2013 blizzard driving down William Floyd and it was horrific from 25a to 495. Once I hit 495, it switched to heavy sleet and rain. The difference over approximately a mile was about twelve inches. Most years that's true. This year it gets a prize for understatement. Taken today from Short Beach in Smithtown: Alas, We aren't going to get much sound enhancement with all that ice Link to comment Share on other sites More sharing options...
The 4 Seasons Posted February 28, 2015 Share Posted February 28, 2015 NAM looks like it increased QPF in the three hour interval between 21Z and 00Z and 00Z and 03Z. Only out to 33 right now. Link to comment Share on other sites More sharing options...
The 4 Seasons Posted February 28, 2015 Share Posted February 28, 2015 Winter Storm Watches up for CT zones. ...WINTER STORM TO IMPACT THE TRI-STATE SUNDAY AND SUNDAYNIGHT...CTZ006>008-010>012-010415-/O.NEW.KOKX.WS.A.0008.150301T1500Z-150302T1200Z/NORTHERN NEW HAVEN-NORTHERN MIDDLESEX-NORTHERN NEW LONDON-SOUTHERN NEW HAVEN-SOUTHERN MIDDLESEX-SOUTHERN NEW LONDON-313 PM EST SAT FEB 28 2015...WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGHMONDAY MORNING...THE NATIONAL WEATHER SERVICE IN NEW YORK HAS ISSUED A WINTERSTORM WATCH...WHICH IS IN EFFECT FROM SUNDAY MORNING THROUGHMONDAY MORNING.* LOCATIONS...SOUTH CENTRAL AND SOUTHEASTERN CONNECTICUT.* HAZARD TYPES...SNOW.* ACCUMULATIONS...4 TO 8 INCHES OF SNOW.* VISIBILITIES...1/4 TO 1/2 MILE OR LESS AT TIMES. Winter Weather Advisories up for NYC and LI zones ...WINTER STORM TO IMPACT THE TRI-STATE SUNDAY AND SUNDAYNIGHT...CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179-010415-/O.NEW.KOKX.WW.Y.0011.150301T1500Z-150302T1200Z/NORTHERN FAIRFIELD-SOUTHERN FAIRFIELD-WESTERN PASSAIC-EASTERN PASSAIC-HUDSON-WESTERN BERGEN-EASTERN BERGEN-WESTERN ESSEX-EASTERN ESSEX-WESTERN UNION-EASTERN UNION-ORANGE-PUTNAM-ROCKLAND-NORTHERN WESTCHESTER-SOUTHERN WESTCHESTER-NEW YORK (MANHATTAN)-BRONX-RICHMOND (STATEN ISLAND)-KINGS (BROOKLYN)-NORTHWESTERN SUFFOLK-NORTHEASTERN SUFFOLK-SOUTHWESTERN SUFFOLK-SOUTHEASTERN SUFFOLK-NORTHERN QUEENS-NORTHERN NASSAU-SOUTHERN QUEENS-SOUTHERN NASSAU-313 PM EST SAT FEB 28 2015...WINTER WEATHER ADVISORY IN EFFECT FROM 10 AM SUNDAY TO 7 AMEST MONDAY...THE NATIONAL WEATHER SERVICE IN NEW YORK HAS ISSUED A WINTERWEATHER ADVISORY FOR SNOW AND FREEZING RAIN...WHICH IS IN EFFECTFROM 10 AM SUNDAY TO 7 AM EST MONDAY.* LOCATIONS...NEW YORK CITY...LONG ISLAND...NORTHEAST NEW JERSEY...THE LOWER HUDSON VALLEY AND FAIRFIELD COUNTY.* HAZARD TYPES...SNOW...WITH FREEZING RAIN ACROSS NEW YORK CITY...LONG ISLAND...MOST OF NORTHEAST NEW JERSEY...AND COASTAL PORTIONS OF THE LOWER HUDSON VALLEY AND FAIRFIELD COUNTY.* ACCUMULATIONS...SNOW ACCUMULATION OF 2 TO 6 INCHES...ALONG WITH UP TO AROUND A TENTH OF AN INCH OF ICE.* VISIBILITIES...1/4 TO 1/2 MILES AT TIMES. Link to comment Share on other sites More sharing options...
NYC Weather Lover Posted February 28, 2015 Share Posted February 28, 2015 Winter weather advisories just issued for most of the region, no watches except in inland Connecticut. Most of Nj is actually under a hazardous weather outlook. Link to comment Share on other sites More sharing options...
PB GFI Posted February 28, 2015 Share Posted February 28, 2015 Most years that's true. This year it gets a prize for understatement. Taken today from Short Beach in Smithtown: 20150228SeaIce-054s1000.jpg Alas, We aren't going to get much sound enhancement with all that ice Looks like Hudson bay. Lol. Link to comment Share on other sites More sharing options...
PB GFI Posted February 28, 2015 Share Posted February 28, 2015 Winter Storm Watches up for CT zones. ...WINTER STORM TO IMPACT THE TRI-STATE SUNDAY AND SUNDAY NIGHT... CTZ006>008-010>012-010415- /O.NEW.KOKX.WS.A.0008.150301T1500Z-150302T1200Z/ NORTHERN NEW HAVEN-NORTHERN MIDDLESEX-NORTHERN NEW LONDON- SOUTHERN NEW HAVEN-SOUTHERN MIDDLESEX-SOUTHERN NEW LONDON- 313 PM EST SAT FEB 28 2015 ...WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGH MONDAY MORNING... THE NATIONAL WEATHER SERVICE IN NEW YORK HAS ISSUED A WINTER STORM WATCH...WHICH IS IN EFFECT FROM SUNDAY MORNING THROUGH MONDAY MORNING. * LOCATIONS...SOUTH CENTRAL AND SOUTHEASTERN CONNECTICUT. * HAZARD TYPES...SNOW. * ACCUMULATIONS...4 TO 8 INCHES OF SNOW. * VISIBILITIES...1/4 TO 1/2 MILE OR LESS AT TIMES. Winter Weather Advisories up for NYC and LI zones ...WINTER STORM TO IMPACT THE TRI-STATE SUNDAY AND SUNDAY NIGHT... CTZ005-009-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179- 010415- /O.NEW.KOKX.WW.Y.0011.150301T1500Z-150302T1200Z/ NORTHERN FAIRFIELD-SOUTHERN FAIRFIELD-WESTERN PASSAIC- EASTERN PASSAIC-HUDSON-WESTERN BERGEN-EASTERN BERGEN- WESTERN ESSEX-EASTERN ESSEX-WESTERN UNION-EASTERN UNION-ORANGE- PUTNAM-ROCKLAND-NORTHERN WESTCHESTER-SOUTHERN WESTCHESTER- NEW YORK (MANHATTAN)-BRONX-RICHMOND (STATEN ISLAND)- KINGS (BROOKLYN)-NORTHWESTERN SUFFOLK-NORTHEASTERN SUFFOLK- SOUTHWESTERN SUFFOLK-SOUTHEASTERN SUFFOLK-NORTHERN QUEENS- NORTHERN NASSAU-SOUTHERN QUEENS-SOUTHERN NASSAU- 313 PM EST SAT FEB 28 2015 ...WINTER WEATHER ADVISORY IN EFFECT FROM 10 AM SUNDAY TO 7 AM EST MONDAY... THE NATIONAL WEATHER SERVICE IN NEW YORK HAS ISSUED A WINTER WEATHER ADVISORY FOR SNOW AND FREEZING RAIN...WHICH IS IN EFFECT FROM 10 AM SUNDAY TO 7 AM EST MONDAY. * LOCATIONS...NEW YORK CITY...LONG ISLAND...NORTHEAST NEW JERSEY...THE LOWER HUDSON VALLEY AND FAIRFIELD COUNTY. * HAZARD TYPES...SNOW...WITH FREEZING RAIN ACROSS NEW YORK CITY...LONG ISLAND...MOST OF NORTHEAST NEW JERSEY...AND COASTAL PORTIONS OF THE LOWER HUDSON VALLEY AND FAIRFIELD COUNTY. * ACCUMULATIONS...SNOW ACCUMULATION OF 2 TO 6 INCHES...ALONG WITH UP TO AROUND A TENTH OF AN INCH OF ICE. * VISIBILITIES...1/4 TO 1/2 MILES AT TIMES. 2 to 6 not bad. Much better than 1 to 2. Should end up 4 to 6 but that's a big jump since this AM Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 28, 2015 Share Posted February 28, 2015 From SV NCEP is still experiencing delays in delivering model data to its ftp server today (2/28). (Affecting HRRR, NAM, and GFS products) Link to comment Share on other sites More sharing options...
WintersGrasp Posted February 28, 2015 Share Posted February 28, 2015 2 to 6 not bad. Much better than 1 to 2. Should end up 4 to 6 but that's a big jump since this AM I guess since 2-6 is such a range, they are thinking a couple inches for most of NYC, LI, and NENJ with the higher amounts N since this covers CT.....seems like a good call.....2-3" with some 4s for most, and 4-7" with some 8s north Link to comment Share on other sites More sharing options...
The 4 Seasons Posted February 28, 2015 Share Posted February 28, 2015 Yeah, that storm total forecast map should look a lot different than it did this morning. My first call map yesterday afternoon was for 3-7" for all of CT, going to probably add an inch on both ends for 4-8 statewide, ratios should be a bit higher in the NW to make up for the lesser QPF totals. Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 28, 2015 Share Posted February 28, 2015 http://www.weather.gov/wwamap/wwatxtget.php?cwa=phi&wwa=phi Link to comment Share on other sites More sharing options...
PB GFI Posted February 28, 2015 Share Posted February 28, 2015 I guess since 2-6 is such a range, they are thinking a couple inches for most of NYC, LI, and NENJ with the higher amounts N since this covers CT.....seems like a good call.....2-3" with some 4s for most, and 4-7" with some 8s northIt's 4 to 6. Slowly stepping there. 18z NAM is out. Looks very good. I think there is 3 to 4 in Monmouth. 4 to 5 KNYC . 6 to 7 N shore of a LI and NNJ 7 to 8 CT Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 28, 2015 Share Posted February 28, 2015 Advisory here for 3-5" of snow and a trace of ice. Link to comment Share on other sites More sharing options...
wkd Posted February 28, 2015 Share Posted February 28, 2015 Link to comment Share on other sites More sharing options...
RU848789 Posted February 28, 2015 Share Posted February 28, 2015 New map up for Mt. Holly - increases across the board, as expected, given the 12Z model suite...2-3" for my house, which is what I said above, so, I'd be happy with that in early March. Link to comment Share on other sites More sharing options...
WintersGrasp Posted February 28, 2015 Share Posted February 28, 2015 New map up for Mt. Holly - increases across the board, as expected, given the 12Z model suite...2-3" for my house, which is what I said above, so, I'd be happy with that in early March. Awesome map.....unless something changes, that looks like it could be very accurate Link to comment Share on other sites More sharing options...
snowman19 Posted February 28, 2015 Share Posted February 28, 2015 Advisory here for 3-5" of snow and a trace of ice.They sped up the timing too, starts late morning, west to east, over and done around midnight Link to comment Share on other sites More sharing options...
Guest Pamela Posted February 28, 2015 Share Posted February 28, 2015 The 12z ARW & 12z GEM LAM were actually pretty dry over North Jersey & NYC...like a 2 to 3 inch event...the ARW was spot on the day before the January blizzard (little snow west of the Hudson) and we all know the LAM has done very nicely. I suppose as the air downslopes down the Kittatinies; significant drying is anticipated...QPF for CT & LI remain about the same as the other models though. Link to comment Share on other sites More sharing options...
SomeWeatherGeek Posted February 28, 2015 Share Posted February 28, 2015 New map up for Mt. Holly - increases across the board, as expected, given the 12Z model suite...2-3" for my house, which is what I said above, so, I'd be happy with that in early March. still a bit conservative imo. 4-6 looks likely for NYC 5 boroughs Link to comment Share on other sites More sharing options...
UlsterCountySnowZ Posted February 28, 2015 Share Posted February 28, 2015 still a bit conservative imo. 4-6 looks likely for NYC 5 boroughs Are you ever conservative? Lol Link to comment Share on other sites More sharing options...
The 4 Seasons Posted February 28, 2015 Share Posted February 28, 2015 New Upton map. Link to comment Share on other sites More sharing options...
snowman19 Posted February 28, 2015 Share Posted February 28, 2015 The 12z ARW & 12z GEM LAM were actually pretty dry over North Jersey & NYC...like a 2 to 3 inch event...the ARW was spot on the day before the January blizzard (little snow west of the Hudson) and we all know the LAM has done very nicely. I suppose as the air downslopes down the Kittatinies; significant drying is anticipated...QPF for CT & LI remain about the same as the other models though. 2-3 wouldn't be bad Link to comment Share on other sites More sharing options...
SomeWeatherGeek Posted February 28, 2015 Share Posted February 28, 2015 Are you ever conservative? Lol lol I'm always optimistic when the trend goes our way. You can't deny the colder trend. Btw off topic but the wave after tomorrow looks like an incoming snow to an ice (nam) storm for our area. I am really excited because 2-3 days ago that was depicted as mostly rain! And of course I'm also excited about the third wave that looks like a good period of snow for us! Especially the coastal sections! February 3rd 2014 comes into mindSent from my iPhone Link to comment Share on other sites More sharing options...
Doorman Posted February 28, 2015 Share Posted February 28, 2015 mojo http://climate.cod.edu/flanis/satellite/reg/index.php?type=northeast-vis-24 Link to comment Share on other sites More sharing options...
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