SnowGoose69 Posted November 27, 2012 Share Posted November 27, 2012 This is the problem with November snows around here, you need dynamic lows which we had two weeks ago and not this time, although one can argue the Thanksgiving 1989 storm was not the most dynamic storm ever. The 1995 one was not either, there was alot more cold air infiltrating though as it was occurring. Link to comment Share on other sites More sharing options...
Guest Pamela Posted November 27, 2012 Share Posted November 27, 2012 This is the problem with November snows around here, you need dynamic lows which we had two weeks ago and not this time, although one can argue the Thanksgiving 1989 storm was not the most dynamic storm ever. ...and of course, the cold anticyclone must be in place....I don't know what we are under now...saw six separate centers of high pressure over New England and eastern Canada with one model run... Link to comment Share on other sites More sharing options...
famartin Posted November 27, 2012 Share Posted November 27, 2012 This is the problem with November snows around here, you need dynamic lows which we had two weeks ago and not this time, although one can argue the Thanksgiving 1989 storm was not the most dynamic storm ever. That was a very cold storm. Much colder than this (or November 7 for that matter). Link to comment Share on other sites More sharing options...
tmagan Posted November 27, 2012 Share Posted November 27, 2012 Of course doesn't help with water temperatures near fifty degrees either. Link to comment Share on other sites More sharing options...
Ericjcrash Posted November 27, 2012 Share Posted November 27, 2012 I have to admit being somewhat mystified by the degree of the warmup many of the models (including the latest 0z RGEM) seem to be indicating. It seems that whatever cold air is currently in place will quickly be eroded as marine air engulfs the immediate coast. I didn't buy it when I saw a few models show it the other day...but with less than 12 hours to go and it still showing up on some models...it is very troubling to say the least. A Slight N/NE wind wouldn't warm us up so much IMO. Link to comment Share on other sites More sharing options...
Storm At Sea Posted November 27, 2012 Share Posted November 27, 2012 Stagnant, unimpressive airmass. 35 this hour up in Syracuse. Link to comment Share on other sites More sharing options...
Guest Pamela Posted November 27, 2012 Share Posted November 27, 2012 A Slight N/NE wind wouldn't warm us up so much IMO. I agree with you and that is what I wrote last night....thats where the *mystified* part comes in.... Link to comment Share on other sites More sharing options...
uofmiami Posted November 27, 2012 Share Posted November 27, 2012 Are the winds suppose to be east off the water? NAM Fous data I saw is all NE to N wind, so water temps should not be an issue. What models are showing an Easterly wind to be concerned about with this upcoming event? Link to comment Share on other sites More sharing options...
Chris L Posted November 27, 2012 Share Posted November 27, 2012 1-2" for the area is probable depending on the NAM, but I'd be surprised if we get any totals on the pavement sfc, but the grassy sfc, most likely will see. Link to comment Share on other sites More sharing options...
Ericjcrash Posted November 27, 2012 Share Posted November 27, 2012 Are the winds suppose to be east off the water? NAM Fous data I saw is all NE to N wind, so water temps should not be an issue. What models are showing an Easterly wind to be concerned about with this upcoming event? N/NE Link to comment Share on other sites More sharing options...
Guest Pamela Posted November 27, 2012 Share Posted November 27, 2012 Of course doesn't help with water temperatures near fifty degrees either. Seriously, the RGEM isn't even close to snow here...it has rain in NE CT...for it to be off by that much...would be positively monumental. Link to comment Share on other sites More sharing options...
kevbo81 Posted November 27, 2012 Share Posted November 27, 2012 .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... 00Z NAM SUPPORTED BY THE 12Z ECMWF. THIS PLACES THE MAIN MID LVL FROGEN OVER THE SRN 2/3 OF THE CWA TUE. THE 12Z ECMWF INDICATED -4C AT H85 THRU THE CITY FOR THE ENTIRETY OF THE EVENT. THE 00Z NAM HAS FOLLOWED SUIT WITH -4C OR COLDER ACROSS MOST OF THE CWA. THICKNESSES IN THE 12Z ECMWF/18Z GFS/00Z NAM NEVER GET ABV 537 DAM. THIS LENDS TO INCREASED CONFIDENCE IN A MAINLY SNOW EVENT. LIMITING FACTOR FOR SNOW ACCUMS WILL BE SFC TEMPS. WARMER SFC TEMP INFLUENCE ACROSS THE CITY AND LI WITH NNE/NE FLOW OFF THE WATER. IN ADDITION TO LLVL TEMPS...ANY DISPLACEMENT OF THE HEAVIEST BAND TO THE S WILL SERVE AS A SECOND LIMITING FACTOR AND GREATLY REDUCE ACCUMS. HAVE BUMPED UP SNOWFALL FOR THE ENTIRE AREA WITH THIS UPDATE. NAM SNOW ALGORITHM...ALTHOUGH USUALLY ON THE HIGH SIDE...DOES PRODUCE A 10 INCH POTENTIAL WHERE THE HEAVY BAND SETS UP. A GOOD RULE OF THUMB IS TO TAKE THIS VALUE AND DIVIDE BY 2...SO MAX AROUND 5 INCHES IN THE BAND. HAVE BEEN CONSERVATIVE WITH THE SNOW TOTAL UPDATE...AS IT IS BASED MAINLY ON THE 12Z ECMWF...00Z NAM AND TRENDS. WILL ALLOW SUBSEQUENT FCSTS TO INCORPORATE THE REMAINDER OF THE 00Z DATA AS IT COMES IN TNGT. THE PRECIPITATION ENDS FROM NORTHWEST TO SOUTHEAST TUE EVENING WITH LOWS FALLING INTO THE 20S AND 30S. NYC SHOULD STAY JUST ABOVE THE FREEZING MARK WITH TEMPERATURES RANGING FROM 32 TO 35 DEGREES. Link to comment Share on other sites More sharing options...
famartin Posted November 27, 2012 Share Posted November 27, 2012 The problem with the lighter wind is that it has more residence time over the water to be influenced by it. It also means it won't have as much influence further inland. But if you are near a coast where the wind will be coming off the water itself... Link to comment Share on other sites More sharing options...
ag3 Posted November 27, 2012 Share Posted November 27, 2012 Seriously, the RGEM isn't even close to snow here...it has rain in NE CT...for it to be off by that much...would be positively monumental. GFS is even worse. Rain/Snow line is almost all the way into PA. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted November 27, 2012 Share Posted November 27, 2012 The problem with the lighter wind is that it has more residence time over the water to be influenced by it. It also means it won't have as much influence further inland. But if you are near a coast where the wind will be coming off the water itself... That's a good point regarding the duration of the fetch. It won't traverse very far, but where it does hit would be affected. Immediate north shore beaches would seem to suffer more, intuitively, than the immediate south shore. ...though that seems odd to say. But of course, the hillier north shore regions not along the water will still do better than most locations on Long Island in this setup -- all else being equal. Link to comment Share on other sites More sharing options...
earthlight Posted November 27, 2012 Share Posted November 27, 2012 The RGEM is starting to get warmer now...which is definitely concerning for the immediate suburbs. Link to comment Share on other sites More sharing options...
famartin Posted November 27, 2012 Share Posted November 27, 2012 Given latest trends, I'll allow a coating to an inch or so in the city. Not much different from my earlier Trenton forecast (which was coating most likely, maybe 1-2" if a heavier band develops over them) Link to comment Share on other sites More sharing options...
Mitchel Volk Posted November 27, 2012 Share Posted November 27, 2012 The N to NE winds will be a problem for the Jersey shore and maybe parts of LI, but the city it will not. In addition, the winds pick up to about 15mph by the afternoon so temperatures should drop in the afternoon. The moderate rate of snow should help cool the air down too, also I think the FOUS data is a little too warm for the NYC Metro. So 1" to 4 for the city. Link to comment Share on other sites More sharing options...
ag3 Posted November 27, 2012 Share Posted November 27, 2012 Of course doesn't help with water temperatures near fifty degrees either. The sound is 44-47 degrees right now. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted November 27, 2012 Share Posted November 27, 2012 The RGEM is starting to get warmer now...which is definitely concerning for the immediate suburbs. I wonder what's causing this, despite the trends to increase precipitation. Perhaps the storm itself nudging a tad north is making a difference. Link to comment Share on other sites More sharing options...
Guest Pamela Posted November 27, 2012 Share Posted November 27, 2012 That's a good point regarding the duration of the fetch. It won't traverse very far, but where it does hit would be affected. Immediate north shore beaches would seem to suffer more, intuitively, than the immediate south shore. ...though that seems odd to say. But of course, the hillier north shore regions not along the water will still do better than most locations on Long Island in this setup -- all else being equal. I'll see what the SUNY model has to say...I trust it the most as it usually can nail the r/s line by as little as two city blocks. Link to comment Share on other sites More sharing options...
MJO812 Posted November 27, 2012 Share Posted November 27, 2012 1-2" for the area is probable depending on the NAM, but I'd be surprised if we get any totals on the pavement sfc, but the grassy sfc, most likely will see. Nick Gregory is going with 1-2 inches for NYC and 2-4 just outside of NYC. Link to comment Share on other sites More sharing options...
SnowGoose69 Posted November 27, 2012 Share Posted November 27, 2012 I'll see what the SUNY model has to say...I trust it the most as it usually can nail the r/s line by as little as two city blocks. It usually is somewhat similar to the NAM since its run off its grid I believe, if it varies largely from the NAM its a red flag. Link to comment Share on other sites More sharing options...
famartin Posted November 27, 2012 Share Posted November 27, 2012 I wonder what's causing this, despite the trends to increase precipitation. Perhaps the storm itself nudging a tad north is making a difference. I noticed the LLJ on the NAM seems to be stronger than before. A pronounced warm push is noticeable on PHL's sounding which makes them mainly rain. It may be that its simply shoving more warm air northward to generate all this enhanced precip. Link to comment Share on other sites More sharing options...
Guest Pamela Posted November 27, 2012 Share Posted November 27, 2012 It usually is somewhat similar to the NAM since its run off its grid I believe, if it varies largely from the NAM its a red flag. I thought it was the old ETA...but you may be right...has the line right over NYC at 7 AM, btw (it is that far along in its midnight run) as precip is moving in at that hour. Link to comment Share on other sites More sharing options...
ORH_wxman Posted November 27, 2012 Share Posted November 27, 2012 I wonder what's causing this, despite the trends to increase precipitation. Perhaps the storm itself nudging a tad north is making a difference. If you look at the BL in the 950mb-975mb range, a stronger system is going to increase this flow out of the ENE...the NAM warms this level between 15z and 18z despite the precip increasing because of the ENE flow. The precip intensity is able to fight it off though and it levels out...also the winds start turn more NE in the BL as the system moves east. The RGEM is probably pushing this BL warmth a little more inland. But it should be watched. This is often the difference between a 35F and rain and 35F with snow falling when 850s are cold enough to snow. Link to comment Share on other sites More sharing options...
Wxoutlooksblog Posted November 27, 2012 Share Posted November 27, 2012 Are the winds suppose to be east off the water? NAM Fous data I saw is all NE to N wind, so water temps should not be an issue. What models are showing an Easterly wind to be concerned about with this upcoming event? Yes, I think once the precipitation starts, all levels should cool sufficiently for this to become an all-out snow event. I do not really see enough of an easterly component of the wind to counter the evaporational and dynamic cooling. It will be a wet snow, however, and as usual should not accumulate easily to pavement. But on grassy surfaces I think somebody in the area will see 6", while most of us will see in the 1-4" range. WX/PT Link to comment Share on other sites More sharing options...
earthlight Posted November 27, 2012 Share Posted November 27, 2012 If you look at the BL in the 950mb-975mb range, a stronger system is going to increase this flow out of the ENE...the NAM warms this level between 15z and 18z despite the precip increasing because of the ENE flow. The precip intensity is able to fight it off though and it levels out...also the winds start turn more NE in the BL as the system moves east. The RGEM is probably pushing this BL warmth a little more inland. But it should be watched. This is often the difference between a 35F and rain and 35F with snow falling when 850s are cold enough to snow. It's been ticking the low level warming up each run a little bit...but the RGEM jumped pretty good there at 00z and now flips the city to all rain during the event and keeps even the surrounding suburbs a sn/ra mix. This has me a little iffy now given the NAM's tendency to like to jump a little too far on the banding and lift ... which could be causing it to dynamically cool the column. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted November 27, 2012 Share Posted November 27, 2012 I noticed the LLJ on the NAM seems to be stronger than before. A pronounced warm push is noticeable on PHL's sounding which makes them mainly rain. It may be that its simply shoving more warm air northward to generate all this enhanced precip. That would definitely make sense. The increased overrunning precip it's showing is a product of more efficient warm air advection to the south colliding with cold air advection that has NOT increased in strength. Thus, you're generating more frontogenesis and lift for precip, but at the cost of advecting a bit more warmer air. The more dynamic systems have a much more efficient area of cold air advection on the cold side of the storm -- thus the CCB. We're not really going to be having a CCB, here. Link to comment Share on other sites More sharing options...
earthlight Posted November 27, 2012 Share Posted November 27, 2012 That would definitely make sense. The increased overrunning precip it's showing is a product of more efficient warm air advection to the south colliding with cold air advection that has NOT increased in strength. Thus, you're generating more frontogenesis and lift for precip, but at the cost of advecting a bit more warmer air. The more dynamic systems have a much more efficient area of cold air advection on the cold side of the storm -- thus the CCB. We're not really going to be having a CCB, here. You can see the WAA surge at the 850mb level, too. SV has the 925mb temperature graphics and you can see the WAA bring the 0c line up to Monmouth County NJ -- and as soundings confirm a little warmer layer below 900mb. But here's the loop for illustrative purposes. http://www.meteo.psu.edu/~fxg1/NAMSFC4_0z/8loop.html Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.