Santa Clause Posted December 26, 2012 Share Posted December 26, 2012 Some guesses Unv: 5-9 Ipt : 3-6 Aoo: 4-8 Jst: 4-8 MDT: 2-4 Avp: 3-6 Lbs: 1-2 Link to comment Share on other sites More sharing options...
WmsptWx Posted December 26, 2012 Share Posted December 26, 2012 Hoping for a little more than 3.9 inches up here, although if it never changes over to liquid, I'll consider that a sufficient consolation prize. Link to comment Share on other sites More sharing options...
canderson Posted December 26, 2012 Share Posted December 26, 2012 This looks like a classic Turnpike divider enhanced by CAD. The Johnstown - UNV - IPT corridor north should bank with this one. MDT will get a decent slop before the rain kills it, while LNS and York see a bunch of rain. Link to comment Share on other sites More sharing options...
NortheastPAWx Posted December 26, 2012 Author Share Posted December 26, 2012 UK still pretty cool...drama-free all snow event 80N. Link to comment Share on other sites More sharing options...
Santa Clause Posted December 26, 2012 Share Posted December 26, 2012 PSU I have a feeling you and I will be in this together mixing wise. Link to comment Share on other sites More sharing options...
JamieOber Posted December 26, 2012 Share Posted December 26, 2012 If we get 8-9 inches of snow with some sleet and ice on top, that kind of snowcover is hard to get rid of. We had a solid snowcover for much of the winter in 2003-2004 around here due to that. Link to comment Share on other sites More sharing options...
NortheastPAWx Posted December 26, 2012 Author Share Posted December 26, 2012 ^ Not like the 2007 V-Day storm with 13" of snow and 4-5" of sleet which froze under temps <5°F! That pack stuck around until late March. Link to comment Share on other sites More sharing options...
Jim Marusak Posted December 26, 2012 Share Posted December 26, 2012 have to admit, i've been stuck here in the mid-west pattern for a while but just am looking back in NEPA for the folks, now that I have the time to after working 12 straight. have the NAM and GFS been running as warm in northeast and north-central PA on a run-to-run basis with this thing? or is this a one-run anomaly and i should go with a more canadian regional/euros solution for this? and how have the 850's been trending up here for this event? catch me up to speed real quick. Link to comment Share on other sites More sharing options...
Jim Marusak Posted December 26, 2012 Share Posted December 26, 2012 ^ Not like the 2007 V-Day storm with 13" of snow and 4-5" of sleet which froze under temps <5°F! That pack stuck around until late March. that was a total CF, i remember that one because to most people i knew i was saying 12 or so" of snow, then all of a sudden, about 6 hrs early, i started hearing sleet at the house in honey pot, and saw the freezing rain way too early into reading and the IP way too early into the i-78 corridor. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 The NAM and GFS both had initialization errors with their 850 temperatures being to warm. The NAMs was more significant I believe. . The GFS error was more up in the OH valley. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 MODEL DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 1121 PM EST TUE DEC 25 2012 VALID DEC 26/0000 UTC THRU DEC 29/1200 UTC STORM MOVING ACROSS THE SOUTH AND EAST ====================================== PREFERENCE: NON-NAM COMPROMISE WITH AVERAGE CONFIDENCE INITIALLY, THE 00Z NAM APPEARS TO BE 2-3C TOO WARM WITH ITS 850 HPA FREEZING LINE ACROSS VIRGINIA/MARYLAND AND THE UPPER OHIO VALLEY. THE 00Z GFS PROBLEMS ARE CONSTRAINED TO A 2-3C ERROR IN THE UPPER OHIO VALLEY. THESE 850 HPA TEMPERATURE ERRORS HAVE POSSIBLE IMPLICATIONS FOR THEIR FORECAST WINTER WEATHER PRECIPITATION TYPES EARLY ON. SEE WINTER WEATHER GRAPHICS/PRODUCTS FROM HPC AND LOCAL FORECAST OFFICES FOR MORE ON SNOW/SLEET/FREEZING RAIN EXPECTATIONS WITH THIS CYCLONE. DURING THE SHORT RANGE PERIOD, THE 00Z NAM BECOMES A SLOWER THAN THE REMAINDER OF THE GUIDANCE WITH THE SYSTEM MOVING THROUGH THE NORTHEAST FROM LATE THURSDAY ONWARD, AND LIES NEAR THE SOUTHWEST CORNER OF THE 12Z GLOBAL ENSEMBLE SPREAD WITH ITS ASSOCIATED SURFACE LOW POSITION FRIDAY MORNING. TREND-WISE, THE GUIDANCE HAS STRENGTHENED THIS SYSTEM OVER THEIR PAST DAY OF RUNS, BUT THE NAM HAS STOPPED TRENDING QUICKER/NORTHEAST. WITH THE 21Z SREF/18Z GEFS/12Z ECMWF ENSEMBLE MEANS SUPPORTING THE QUICKER NON-NAM CONSENSUS, THE PREFERENCE IS FOR A NON-NAM COMPROMISE HERE WITH AVERAGE CONFIDENCE CONSIDERING ITS PROGRESSIVE NATURE. ...MODEL TREND GRAPHICS AT www.hpc.ncep.noaa.gov/html/model2.shtml ...500 MB FORECASTS AT www.hpc.ncep.noaa.gov/h5pref/h5pref.shtml Link to comment Share on other sites More sharing options...
Santa Clause Posted December 26, 2012 Share Posted December 26, 2012 Wow...guess that could skew things. Off quite a bit. Link to comment Share on other sites More sharing options...
Jim Marusak Posted December 26, 2012 Share Posted December 26, 2012 The NAM and GFS both had initialization errors with their 850 temperatures being to warm. The NAMs was more significant I believe. . The GFS error was more up in the OH valley. it definitely looks way warm at 850 at AVP in both models, ~ +4C at AVP at the peak with the NAM and the GFS compared to say 0C that I could estimate off the canadian. that would explain it a lot if the initalization was that bad. was it a bad RAOB upstream that caused it, convective contamination from down south, or just a bad smoothing job? Link to comment Share on other sites More sharing options...
jm1220 Posted December 26, 2012 Share Posted December 26, 2012 Wow...guess that could skew things. Off quite a bit. Mixing oftentimes makes it north of where predictions have it in these kind of mid level WAA events. The most obvious example is VD 2007 when most of PA mixed, but just prior to the storm progs only had mixing up to maybe Rt. 22. I remember seeing the mix line charging north through JST/AOO and knew we were cooked in State College. We had about a foot of cement at the end of it. We had stinging sleet and temps in the teens. Wicked. I would expect mixing of some sort to make it to I-80 before the storm's done, but hopefully most of the precip is done by then. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 I've heard convection with the NAM and upstream with the GFS. Neither I feel handled the strength of the storms in the south this evening particularly well. I'm located just west of Harrisburg and I'm starting to fear a nasty ice storm here. The temperature is 29 and falling in Camp Hill with a dew point of 20. Winds are just slightly the NNE (10 degrees) and the barometer just stopped rising just after midnight. That high pressure is doing a number here. Link to comment Share on other sites More sharing options...
Jim Marusak Posted December 26, 2012 Share Posted December 26, 2012 Mixing oftentimes makes it north of where predictions have it in these kind of mid level WAA events. The most obvious example is VD 2007 when most of PA mixed, but just prior to the storm progs only had mixing up to maybe Rt. 22. I remember seeing the mix line charging north through JST/AOO and knew we were cooked in State College. We had about a foot of cement at the end of it. We had stinging sleet and temps in the teens. Wicked. I would expect mixing of some sort to make it to I-80 before the storm's done, but hopefully most of the precip is done by then. this may be one where everyone in here may have to be a bit of a mesonet point for p-type to see the final verdict. because that's exactly how the calls had to be changed on the VD-2007 storm. and unfortunately, the signals weren't timely enough with the PennDot district in charge of the I-78 corridor, and they needed to get people out of their cars with the National guard. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 Down to 27, DP of 19. I'm just starting to worry about a freezing rain event here >.25 Link to comment Share on other sites More sharing options...
Jim Marusak Posted December 26, 2012 Share Posted December 26, 2012 I've heard convection with the NAM and upstream with the GFS. Neither I feel handled the strength of the storms in the south this evening particularly well. I'm located just west of Harrisburg and I'm starting to fear a nasty ice storm here. The temperature is 29 and falling in Camp Hill with a dew point of 20. Winds are just slightly the NNE (10 degrees) and the barometer just stopped rising just after midnight. That high pressure is doing a number here. hopefully they can get that corrected for the 06Z run, that should be initalized soon. because if not, I may start to wonder if that modified 3dvar they're running for initialization is really part of the problem. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 Anyone know any details of the EURO for 0Z? Link to comment Share on other sites More sharing options...
MAG5035 Posted December 26, 2012 Share Posted December 26, 2012 Final call map on the storm, no major changes. Evened the 6" line out a bit in eastern PA so it is running pretty much right thru Scranton attm. Million dollar question is how much mixing gets into this region, if NE PA manages to stay all snow, they're going to get the 10-14 forecasted further west. It continues to be American vs foreign guidance in that regard with NAM/GFS and co. continuing to ram mixing up into NE PA. I left the line over Scranton/WB as they will likely be a couple inches either side of 6" (aka 4-8 inches). 3 inch line unchanged except for shrinking the SW PA hole a bit. Widened 10-14" zone in the north. That's interesting about the model initialization errors on the 850 temps... certainly something to monitor. I've not really liked the NAM's warm take on this system since this event has gotten into its range. The GFS is a little better but still kind of warm for this setup with a high to the north and sufficient CAD. I think alot of mixing that occurs will be in the form of sleet in C-PA, with liquid mainly relegated south and east of Harrisburg. I don't really see a deep push of very warm air at the lowest levels. Very highly anomalous easterly 850 winds were cited as possible cause of warming that particular layer enough to mix in some of the area. I'm beginning to think this is going to be like our cutter event bout 5 days ago in that the main bulk of precip comes in a major slug a bit ahead of the low. I just wonder if it outruns enough to be able to thump more snow in Sus Valley places before mixing and/or changing. Euro is coming in cold again btw by looks of text data. Gonna be very interesting to see if it ends up winning this thermal battle. My map will be too low amount wise in alot of the southeast if these colder Euro runs straight up verify. Link to comment Share on other sites More sharing options...
wawarriors4 Posted December 26, 2012 Share Posted December 26, 2012 Euro seems about the same.....if not a touch colder. Sitting in Pittston, PA under absolutely clear skies and radiating nicely. Temp 21 DP 15, pressure 30.28, feels like a winter storm is on the way! Link to comment Share on other sites More sharing options...
2001kx Posted December 26, 2012 Share Posted December 26, 2012 Final call map on the storm, no major changes. Evened the 6" line out a bit in eastern PA so it is running pretty much right thru Scranton attm. Million dollar question is how much mixing gets into this region, if NE PA manages to stay all snow, they're going to get the 10-14 forecasted further west. It continues to be American vs foreign guidance in that regard with NAM/GFS and co. continuing to ram mixing up into NE PA. I left the line over Scranton/WB as they will likely be a couple inches either side of 6" (aka 4-8 inches). 3 inch line unchanged except for shrinking the SW PA hole a bit. Widened 10-14" zone in the north. That's interesting about the model initialization errors on the 850 temps... certainly something to monitor. I've not really liked the NAM's warm take on this system since this event has gotten into its range. The GFS is a little better but still kind of warm for this setup with a high to the north and sufficient CAD. I think alot of mixing that occurs will be in the form of sleet in C-PA, with liquid mainly relegated south and east of Harrisburg. I don't really see a deep push of very warm air at the lowest levels. Very highly anomalous easterly 850 winds were cited as possible cause of warming that particular layer enough to mix in some of the area. I'm beginning to think this is going to be like our cutter event bout 5 days ago in that the main bulk of precip comes in a major slug a bit ahead of the low. I just wonder if it outruns enough to be able to thump more snow in Sus Valley places before mixing and/or changing. Euro is coming in cold again btw by looks of text data. Gonna be very interesting to see if it ends up winning this thermal battle. My map will be too low amount wise in alot of the southeast if these colder Euro runs straight up verify. nice write up mike...been waiting for it. but your just teasing me now with that 10"-14" line being so close Link to comment Share on other sites More sharing options...
WmsptWx Posted December 26, 2012 Share Posted December 26, 2012 Jamie had said earlier today that our Friends in Tulsa had stated that NAM was ****ting the bed with this storm at that point. I guess we can conclude that it's pretty much shat over every square inch of the bed sheets at this point, right? Link to comment Share on other sites More sharing options...
jm1220 Posted December 26, 2012 Share Posted December 26, 2012 I've heard convection with the NAM and upstream with the GFS. Neither I feel handled the strength of the storms in the south this evening particularly well. I'm located just west of Harrisburg and I'm starting to fear a nasty ice storm here. The temperature is 29 and falling in Camp Hill with a dew point of 20. Winds are just slightly the NNE (10 degrees) and the barometer just stopped rising just after midnight. That high pressure is doing a number here. It's a possibility-a lot of times cold surface air is hard to scour out from the Susquehanna Valley. The low looks like it will track roughly along I-95, so lower level warmth could win out. But I would say a lot of slop-sleet and then freezing rain, for many of you guys. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 I expect to go over to slop relatively quickly, it just seems that the cold 2m temperatures love to stay put way longer then expected in these setups around Cumberland county. Link to comment Share on other sites More sharing options...
pawatch Posted December 26, 2012 Share Posted December 26, 2012 Thanks for updates!! Gem looks not so good for some. http://collaboration...pe_gem_reg.html Thanks for the updates! Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 At 3 am that shield of precipitation is flying north. It may make it to Harrisburg by 7 am. Link to comment Share on other sites More sharing options...
Rick G Posted December 26, 2012 Share Posted December 26, 2012 I got called into work and am babysitting a server room, while an air condx is being repaired., beautiful sky clear and cold--23.0 when I left the house. Link to comment Share on other sites More sharing options...
Jns2183 Posted December 26, 2012 Share Posted December 26, 2012 Well 6Z GFS went colder while the NAM went warmer. I'm placing my bets with with colder considering the 0Z NAM had MDT sitting at 32 at this hour and its 27 out currently. Link to comment Share on other sites More sharing options...
Voyager Posted December 26, 2012 Share Posted December 26, 2012 21 here currently so plenty cold for the onset. Link to comment Share on other sites More sharing options...
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