sauss06 Posted January 31, 2014 Share Posted January 31, 2014 So....anyone want to comment on the CTP discussion? I heard that stuff about snowcover and further SE tracks from the older forecasters like Elliot Abrams when I worked at AccuWx. Not sure if that will work to our advantage here. FROM THERE A MORE IMPORTANT CYCLONE IS MADE TO APPROACH FOR WED...AND THERE IS BETTER AGREEMENT ON TIMING BETWEEN THE ECMWF AND GFS/GEFS. THE ECMWF HAS ITS LOW TRACKING INTO WESTERN PA...BEFORE REDEVELOPING QUICKLY OFF THE MID ATL COAST. THE GFS/GEFS ARE BOTH FURTHER SOUTHEAST...WITH THE GEFS BEING THE MOST EAST AND THUS THE COLDEST SET OF SOLUTIONS. AT THIS POINT A WINTRY MIX IS INDICATED BETWEEN THE VARIOUS MODEL OUTCOMES AS WARM AIR FLOODS IN ALOFT...BUT WITH SO MUCH SNOW COVER AND COLD AIR OVER THE GR LAKES AND NE...WOULD NOT BE SURPRISED IF THE EVENTUAL STORM TRACK WANDERS CLOSER TO THE COAST OVER THE NEXT SEVERAL MODEL RUNS. somewhere along the way someone here said cold generates more cold (or something like that) Link to comment Share on other sites More sharing options...
Itstrainingtime Posted January 31, 2014 Share Posted January 31, 2014 I think my snowcover will be long gone by the time the midweek storm comes...unless I get snow on Monday. Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 somewhere along the way someone here said cold generates more cold (or something like that) Somehow it supposedly shifts the storm track south. I think my snowcover will be long gone by the time the midweek storm comes...unless I get snow on Monday. They are referring to the pretty solid snowcover across the NE quarter of the US...well, except for the Williamsport snowhole. Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 There may be some truth to that; greater snow cover leads to a colder air mass which increases cold air damming and strengthens the baroclinic zone over the east coast. Now, the models may have properly initialized the snow cover information meaning that it is already taken into account in the solutions. Also, if the primary low is strong enough, this effect will not make much of a difference with regards to storm track. That's what I thought. Link to comment Share on other sites More sharing options...
Itstrainingtime Posted January 31, 2014 Share Posted January 31, 2014 Somehow it supposedly shifts the storm track south. They are referring to the pretty solid snowcover across the NE quarter of the US...well, except for the Williamsport snowhole. Makes sense. Eric Horst talks about that a good bit too. Link to comment Share on other sites More sharing options...
Mallow Posted January 31, 2014 Share Posted January 31, 2014 Somehow it supposedly shifts the storm track south. They are referring to the pretty solid snowcover across the NE quarter of the US...well, except for the Williamsport snowhole. If you have good snowcover, that provides a cooling source (obviously). That can act to set up the temperature gradient further south, near the border of the snowcover. If the baroclinic zone is further south, the storm track will be as well. However, I don't know how much I buy it in this case... as heavy_wx noted, the models probably have the snowcover reasonably well-modeled, which means (unless there is a model bias to ignore snowcover WRT baroclinity?) they should have a handle on its impacts. Link to comment Share on other sites More sharing options...
Wmsptwx Posted January 31, 2014 Share Posted January 31, 2014 Yea snow cover is thin or non existent over NCPA Link to comment Share on other sites More sharing options...
djr5001 Posted January 31, 2014 Share Posted January 31, 2014 The 00z has a higher amplitude (though still relatively low amplitude) northern stream disturbance than the GFS which phases with the shortwave over the southern plains. That allows for a more northerly track bringing moderate QPF in to much of PA for Monday. Since both shortwaves will be moving fairly quickly it may take some luck for the phase to occur as the Euro depicts. For the Wednesday event, it's the GFS that has a more substantial phase, allowing for the low to be stronger tracking through the Ohio valley into central NY. The Euro was a nice hit for areas north of about Altoona with about 5" or so at UNV. Interestingly, the southern stream vorticity maxima at 500 mb has a more southerly track into northwest Mexico on the GFS vs the Euro. The GFS however has a less amplified disturbance upstream over the four corners region. This disturbance on the Euro is more amplified and destructively interferes with the lead shortwave upstream, keeping the primary low a little weaker in the Ohio valley. In both cases, the Euro seems to be more willing to amplify these northern stream disturbances originating from the North Pacific. It will be interesting to see how these shortwaves progress in both model space and reality as they are better sampled in the next several days. this is the one thing that I often notice which ends up as the GFS' downfall vs Euro... it often struggles with northern and southern energy and timing for phasing/interaction... especially with shorter windows for interaction... I would watch here what Euro does at 12z and again at 0z tonight to see if indeed the speed has it go back and forth... if it stays consistent I would feel it to be slightly more believeable than if it waffles from run to run than what the GFS does Link to comment Share on other sites More sharing options...
Wmsptwx Posted January 31, 2014 Share Posted January 31, 2014 Could someone get djr an orange tag already?? Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 Wmsptwx, snowcover is solid across most of NC PA. Keep in mind, your situation is unique. Although that should change this weekend. Link to comment Share on other sites More sharing options...
NeffsvilleWx Posted January 31, 2014 Share Posted January 31, 2014 Wmsptwx, snowcover is solid across most of NC PA. Keep in mind, your situation is unique. Although that should change this weekend. Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 The NWS map I posted earlier show pa and the IPT hole. Link to comment Share on other sites More sharing options...
sauss06 Posted January 31, 2014 Share Posted January 31, 2014 Could someone get djr an orange tag already?? i agree. The NWS map I posted earlier show pa and the IPT hole. i thought you put the hole on your map Link to comment Share on other sites More sharing options...
pasnownut Posted January 31, 2014 Share Posted January 31, 2014 Thanks. I was just getting ready to do the same.... Nut Link to comment Share on other sites More sharing options...
Wmsptwx Posted January 31, 2014 Share Posted January 31, 2014 It's real believe me. Even a lot of N.Lycoming county just has snow piles. Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 God did, Sauss. He hates IPT Link to comment Share on other sites More sharing options...
NeffsvilleWx Posted January 31, 2014 Share Posted January 31, 2014 Thanks. I was just getting ready to do the same.... Nut Here's the coop data: Link to comment Share on other sites More sharing options...
snowalot Posted January 31, 2014 Share Posted January 31, 2014 Nice article reposted on the Philly side about the model volatility and how we really need to take it one day at a time: http://www.americanwx.com/bb/index.php/topic/38386-vendor-forecast-discussion/?p=2707193 As I said before what you see on the models is not set in stone in any way. This isn't an easy pattern to decipher as the models have shown us. With the atmosphere in transition it truly is down to looking at the present day or two, seeing what the results are and then going from there. Of course since the models show a plethora of solutions, one must have found just the right parameters to display what will happen, but chances are that if the model verifies it won't be because of what it had inputted today. Let's see what today's model suite says about the Monday event. Link to comment Share on other sites More sharing options...
NortheastPAWx Posted January 31, 2014 Share Posted January 31, 2014 Nice article reposted on the Philly side about the model volatility and how we really need to take it one day at a time: http://www.americanwx.com/bb/index.php/topic/38386-vendor-forecast-discussion/?p=2707193 As I said before what you see on the models is not set in stone in any way. This isn't an easy pattern to decipher as the models have shown us. With the atmosphere in transition it truly is down to looking at the present day or two, seeing what the results are and then going from there. Of course since the models show a plethora of solutions, one must have found just the right parameters to display what will happen, but chances are that if the model verifies it won't be because of what it had inputted today. Let's see what today's model suite says about the Monday event. Steve DiMartino is a notorious snowhound. Link to comment Share on other sites More sharing options...
NortheastPAWx Posted January 31, 2014 Share Posted January 31, 2014 Fwiw the 12z GFS snow map indicates essentially no snow from UNV south. Just looking at maps, this run seems like light snow -> light ice -> rainstorm. Link to comment Share on other sites More sharing options...
EasternUSWX Posted January 31, 2014 Share Posted January 31, 2014 Fwiw the 12z GFS snow map indicates essentially no snow from UNV south. Just looking at maps, this run seems like light snow -> light ice -> rainstorm. Continues to trend west and warmer. Barely stays at freezing south of UNV. Link to comment Share on other sites More sharing options...
MillvilleWx Posted January 31, 2014 Share Posted January 31, 2014 Fwiw the 12z GFS snow map indicates essentially no snow from UNV south. Yeah. I see this being a potential for a nasty IP/ZR event south of I-80 in the normal tricky spots in the valleys. The CAD signature before the storm moves in is very well shown on the GFS and the event is still 120 hours away. The MO this winter has been for models to trend colder at surface closer to the event. I'm concerned for areas especially north of Harrisburg. Plenty of precip to work with for sure throughout the region. Our Upstate Subforum should be frothing at the mouth on this run Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 12z is colder...stronger cad. Link to comment Share on other sites More sharing options...
Wmsptwx Posted January 31, 2014 Share Posted January 31, 2014 Looks like a period of ice to rain. Link to comment Share on other sites More sharing options...
EasternUSWX Posted January 31, 2014 Share Posted January 31, 2014 If colder is truly correct then this will be a devastating ice storm. QPF amounts are near 1" before it would get above 32. Link to comment Share on other sites More sharing options...
EasternUSWX Posted January 31, 2014 Share Posted January 31, 2014 CMC back to euro like solution for Monday. Link to comment Share on other sites More sharing options...
JamieOber Posted January 31, 2014 Share Posted January 31, 2014 I can't post the text output given I'm on my phone but most of the qpf is frozen. .53 falls at unv with both 850 and surface below freezing and most of the recipe is done before surface gets to freezing. Link to comment Share on other sites More sharing options...
djr5001 Posted January 31, 2014 Share Posted January 31, 2014 12z is colder...stronger cad. we have seen good over running snow all winter... I really wouldnt be surprised for many to see more front end snow than the models will show prior to a change over Link to comment Share on other sites More sharing options...
djr5001 Posted January 31, 2014 Share Posted January 31, 2014 I can't post the text output given I'm on my phone but most of the qpf is frozen. .53 falls at unv with both 850 and surface below freezing and most of the recipe is done before surface gets to freezing. UNV WED 06Z 05-FEB -3.8 -2.4 1020 97 100 0.57 562 546 WED 12Z 05-FEB 0.9 7.0 1006 100 100 0.89 558 554 WED 18Z 05-FEB 4.0 2.3 1002 100 17 0.07 550 548 THU 00Z 06-FEB -1.1 -6.9 1010 89 50 0.01 543 535 MDT WED 06Z 05-FEB -1.8 0.6 1022 97 98 0.60 565 548 WED 12Z 05-FEB 1.6 6.9 1009 100 89 0.32 562 555 WED 18Z 05-FEB 4.3 5.6 1003 100 89 0.29 556 553 THU 00Z 06-FEB 2.0 -3.9 1009 90 24 0.01 549 542 IPT WED 06Z 05-FEB -3.8 -4.0 1023 96 100 0.29 561 543 WED 12Z 05-FEB 0.7 5.0 1007 99 100 0.94 558 553 WED 18Z 05-FEB 2.4 3.4 1002 100 28 0.22 549 548 THU 00Z 06-FEB -0.2 -6.3 1008 91 62 0.02 541 535 AVP WED 06Z 05-FEB -4.7 -4.8 1025 94 99 0.15 561 542 WED 12Z 05-FEB -0.4 3.9 1011 98 100 0.73 559 551 WED 18Z 05-FEB 2.2 5.2 1003 100 72 0.47 552 550 THU 00Z 06-FEB 0.9 -4.4 1006 97 49 0.02 542 538 LNS WED 06Z 05-FEB -1.6 0.5 1022 98 100 0.54 566 548 WED 12Z 05-FEB 1.3 6.7 1010 100 75 0.28 563 554 WED 18Z 05-FEB 4.9 6.4 1003 100 98 0.41 557 554 THU 00Z 06-FEB 2.3 -3.1 1008 91 21 0.01 550 544 AOO WED 06Z 05-FEB -2.4 1.1 1018 97 98 0.77 564 550 WED 12Z 05-FEB 1.4 9.0 1006 100 99 0.40 560 555 WED 18Z 05-FEB 5.6 2.0 1003 100 20 0.05 552 550 keep in mind too that the GFS will often boost QPF where it assumes is the warm sector by trying to make it more convective than stable... so these could be a little high... high rates would hinder just how much ice accretion we would see too Link to comment Share on other sites More sharing options...
NortheastPAWx Posted January 31, 2014 Share Posted January 31, 2014 Looks like the GGEM is a little further south than the ECM is on the Monday event. Would not take much of a north push to make it a measurable snow. Link to comment Share on other sites More sharing options...
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