MillerA Posted February 13, 2016 Share Posted February 13, 2016 Gsp written at 3am Short term /Sunday through Tuesday/... as of 245 am EST Saturday...considerable uncertainty persists with the wintry weather forecast for Sunday night through Tuesday. One question centers around how quickly the cold and dry Arctic airmass present at onset Sunday night will retreat/modify through the period. Uncertainty also arises over the surface low track forecasts...with the GFS/European model (ecmwf) Camp starting off the surface low west of the mountains and tracking it through the central/southern Appalachians...while the NAM/Gem Camp depict more of a redeveloping Piedmont low to the southeast. These differences will need to be resolved before enough confidence exists to Post a Winter Storm Watch. For the specifics...a northern stream system moving across the upper Midwest on Sunday will extend a warm frontal feature across the southern Appalachians through the day...with associated upglide moisture arriving at middle levels. Lower levels...however...remain mostly dry through late day. Meanwhile...1034 mb surface high pressure will move east through the middle Atlantic region Sunday and offshore Sunday night. The low level thickness trough remaining across the western Carolinas will be cold and dry and favorable for hybrid cold air damming as the precipitation starts ahead of an approaching southern stream wave. The models have trended less amplified and more progressive with this southern wave which sharpens up over the MS River Valley on Monday. A consensus of the varying model profiles promotes a slow warmup with gradual cad erosion late Monday into Monday night. The faster solutions now bring a middle dry slot in quickly behind the wave late Monday night through Tuesday morning...with heaviest precipitation shutting off more quickly. Upglide moisture should get started in earnest across the forecast area before daybreak Monday. Still anticipate nearly all snow at onset with the 850 mb zero degree isotherm along the southern periphery of the forecast area. However...the warm nose aloft should steadily expand and move northward through the day to permit a transition to sleet and then freezing rain throughout most areas by Monday evening. The middle level drying and associated removal of ice nuclei may keep any overnight precipitation rain or freezing rain/freezing drizzle in any lingering colder mountains pockets. Then...northwest upslope moisture on Tuesday morning will diminish through Tuesday afternoon...with a brief lull in precipitation likely. All told...at least advisory snow or ice accums look quite possible for a significant chunk of the forecast area...with mainly the northern mountains at risk of winter storm snow/ice at this point. Winter storm watches could be needed for Monday as early as this afternoon. Link to comment Share on other sites More sharing options...
FallsLake Posted February 13, 2016 Share Posted February 13, 2016 6z GFS is close to the NAM out to hour 60, but it has only .20 or so qpf for RDU. Maybe .35 over towards Greensboro. After that it is warmer eventually taking RDU out of the CAD ~ hour 78. Would look like NW NC could be the jackpot but again temps would be getting close to freezing with heavy rates. Link to comment Share on other sites More sharing options...
MichaelJ Posted February 13, 2016 Share Posted February 13, 2016 We are getting within the range of the NAM's wheelhouse and I would start hugging it as far as thermal profiles and general track is depicted. It tends to overdo precip amounts but it's resolution is an advantage now in most areas Link to comment Share on other sites More sharing options...
Tacoma Posted February 13, 2016 Share Posted February 13, 2016 Gsp written at 3am Short term /Sunday through Tuesday/... as of 245 am EST Saturday...considerable uncertainty persists with the wintry weather forecast for Sunday night through Tuesday. One question centers around how quickly the cold and dry Arctic airmass present at onset Sunday night will retreat/modify through the period. Uncertainty also arises over the surface low track forecasts...with the GFS/European model (ecmwf) Camp starting off the surface low west of the mountains and tracking it through the central/southern Appalachians...while the NAM/Gem Camp depict more of a redeveloping Piedmont low to the southeast. These differences will need to be resolved before enough confidence exists to Post a Winter Storm Watch. For the specifics...a northern stream system moving across the upper Midwest on Sunday will extend a warm frontal feature across the southern Appalachians through the day...with associated upglide moisture arriving at middle levels. Lower levels...however...remain mostly dry through late day. Meanwhile...1034 mb surface high pressure will move east through the middle Atlantic region Sunday and offshore Sunday night. The low level thickness trough remaining across the western Carolinas will be cold and dry and favorable for hybrid cold air damming as the precipitation starts ahead of an approaching southern stream wave. The models have trended less amplified and more progressive with this southern wave which sharpens up over the MS River Valley on Monday. A consensus of the varying model profiles promotes a slow warmup with gradual cad erosion late Monday into Monday night. The faster solutions now bring a middle dry slot in quickly behind the wave late Monday night through Tuesday morning...with heaviest precipitation shutting off more quickly. Upglide moisture should get started in earnest across the forecast area before daybreak Monday. Still anticipate nearly all snow at onset with the 850 mb zero degree isotherm along the southern periphery of the forecast area. However...the warm nose aloft should steadily expand and move northward through the day to permit a transition to sleet and then freezing rain throughout most areas by Monday evening. The middle level drying and associated removal of ice nuclei may keep any overnight precipitation rain or freezing rain/freezing drizzle in any lingering colder mountains pockets. Then...northwest upslope moisture on Tuesday morning will diminish through Tuesday afternoon...with a brief lull in precipitation likely. All told...at least advisory snow or ice accums look quite possible for a significant chunk of the forecast area...with mainly the northern mountains at risk of winter storm snow/ice at this point. Winter storm watches could be needed for Monday as early as this afternoon. can't believe with the trends of a more south track that GSP wouldn't be thinking more folks in the winter storm watch than just the N. Mtns. But then again at 2:45 this morning is when this was put out, GFS has trended south with the storm. Link to comment Share on other sites More sharing options...
AppalachianWedge Posted February 13, 2016 Share Posted February 13, 2016 I have lived in the triad for 40 years and this has all the signs of an over performing storm. I remember multiple times throughout my life that Frank Deal said "get your bread and milk...it's gonna be the big one" and we would sit and wait and watch clouds for 6 hours and then the sun came out. I also have seen like now where there is not a lot of chatter about a storm. What will happen is at the last minute, the NWS will issue a Winter Storm Warning and there will be several people under prepared for this possible ice storm. Link to comment Share on other sites More sharing options...
Tacoma Posted February 13, 2016 Share Posted February 13, 2016 I have lived in the triad for 40 years and this has all the signs of an over performing storm. I remember multiple times throughout my life that Frank Deal said "get your bread and milk...it's gonna be the big one" and we would sit and wait and watch clouds for 6 hours and then the sun came out. I also have seen like now where there is not a lot of chatter about a storm. What will happen is at the last minute, the NWS will issue a Winter Storm Warning and there will be several people under prepared for this possible ice storm. seems like this winter every storm we've had has outperformed the predictions. Link to comment Share on other sites More sharing options...
mackerel_sky Posted February 13, 2016 Share Posted February 13, 2016 We are getting within the range of the NAM's wheelhouse and I would start hugging it as far as thermal profiles and general track is depicted. It tends to overdo precip amounts but it's resolution is an advantage now in most areasIt absolutely nailed the Jan 22/23rd events profiles!! Everybody doing the snow dance and most got alot of sleet, and the NAM got it right! Link to comment Share on other sites More sharing options...
No snow for you Posted February 13, 2016 Share Posted February 13, 2016 Still not buying the huge ice storm for gsp. I think a cold nose will save is like it has many times in the past. Will still fill my cars up with gas and firewood but gsp has been the center of so many ice storms that turned into pingers or sleet. Link to comment Share on other sites More sharing options...
PackGrad05 Posted February 13, 2016 Share Posted February 13, 2016 The 6Z GFS is now giving wake county more frozen than the 6Z NAM They flip flopped lol Link to comment Share on other sites More sharing options...
FallsLake Posted February 13, 2016 Share Posted February 13, 2016 The 6Z GFS is now giving wake county more frozen than the 6Z NAM They flip flopped lol It's better than previous runs but it would still only give .25 or less qpf for most in Wake County. The NAM is closer to .40 (near RDU) Through hour 63 (best accrual time): GFS http://mag.ncep.noaa.gov/Image.php?fhr=063ℑ=data%2Fgfs%2F06%2Fgfs_namer_063_precip_p48.gif&model=gfs&area=namer¶m=precip_p48&group=Model+Guidance&preselected_formatted_cycle_date=20160213+06+UTC&imageSize=M&ps=model NAM http://mag.ncep.noaa.gov/Image.php?fhr=063ℑ=data%2Fnam%2F06%2Fnam_namer_063_precip_p48.gif&model=nam&area=namer¶m=precip_p48&group=Model+Guidance&preselected_formatted_cycle_date=20160213+06+UTC&imageSize=M&ps=model Link to comment Share on other sites More sharing options...
Poimen Posted February 13, 2016 Share Posted February 13, 2016 6z GFS is close to the NAM out to hour 60, but it has only .20 or so qpf for RDU. Maybe .35 over towards Greensboro. After that it is warmer eventually taking RDU out of the CAD ~ hour 78. Would look like NW NC could be the jackpot but again temps would be getting close to freezing with heavy rates. Past experience says the NAM is over doing the amount of QPF here (with the initial thump). I wouldn't be surprised to see its QPF numbers fall more in-line with the GFS in the ensuing cycles. Link to comment Share on other sites More sharing options...
FallsLake Posted February 13, 2016 Share Posted February 13, 2016 Past experience says the NAM is over doing the amount of QPF here (with the initial thump), I wouldn't be surprised to see its QPF number fall more in-line with the GFS in the ensuing cycles. I agree. We could probably take a compromise between the two models for qpf. So at this point, my expectations is ~.25 before temps rise above freezing. Dealing with the CAD, I think we do stay locked in through the the event, but I also think most go above freezing. Lots of mid 30s and rain late Monday night; of course NW NC is the wildcard. Link to comment Share on other sites More sharing options...
Brick Tamland Posted February 13, 2016 Share Posted February 13, 2016 If we get 4 inches of snow, or a couple inches of snow with some sleet and freezing rain, either way it's going to be a mess during the daytime Monday. And if we stay below freezing longer, maybe Tuesday, too. Link to comment Share on other sites More sharing options...
BIG FROSTY Posted February 13, 2016 Share Posted February 13, 2016 06z CMC is sticking to it's guns, But it may not have any ammo? But it has not backed down as of yet!! Link to comment Share on other sites More sharing options...
BIG FROSTY Posted February 13, 2016 Share Posted February 13, 2016 Hr 78 Ice shot Link to comment Share on other sites More sharing options...
PackGrad05 Posted February 13, 2016 Share Posted February 13, 2016 I don't see Tuesday being that big of a deal with the strong rain coming through washing everything away and temps remaining above freezing Link to comment Share on other sites More sharing options...
buckeyefan1 Posted February 13, 2016 Share Posted February 13, 2016 The 06z NAM gives mby .06 of zr with temps at 28 rising to 48.6 with total precip of .51 The 06z GFS gives mby .41 with a temp of 50. Yay rain! Link to comment Share on other sites More sharing options...
UpStateCAD Posted February 13, 2016 Share Posted February 13, 2016 so as of now the GGEM stands basically alone with the extreme cold. It keeps the wedge firmly locked in well into Tuesday for the Upstate and NE Ga (upper to 20's to boot) GFS has taken a baby step to a colder, wetter solution. I can say one thing the Canadian has been rock solid in it's solution. Seems to be getting more extreme each run. I hope it is wrong at least regarding QPF. Link to comment Share on other sites More sharing options...
ozmaea Posted February 13, 2016 Share Posted February 13, 2016 so as of now the GGEM stands basically alone with the extreme cold. It keeps the wedge firmly locked in well into Tuesday for the Upstate and NE Ga (upper to 20's to boot) GFS has taken a baby step to a colder, wetter solution. I can say one thing the Canadian has been rock solid in it's solution. Seems to be getting more extreme each run. I hope it is wrong at least regarding QPF.So what's your precip type forecast for Greer area Monday Sent from my SM-G900P using Tapatalk Link to comment Share on other sites More sharing options...
Stormsfury Posted February 13, 2016 Share Posted February 13, 2016 The 06z NAM gives mby .06 of zr with temps at 28 rising to 48.6 with total precip of .51 The 60z GFS gives mby .41 with a temp of 50. Yay rain! the GFS is so bad, it has to be run at 60z! Seriously, I have thought in 2016, we wouldn't ever see such model confusion. Problem is, this high will not be able to park. Kind of hard to do with a strong surface low around Greenland. On that same note, watch dewpoint depressions today and tomorrow in SC/NC. This airmass should be exceptionally dry and the last major winter storm, the warm front never made it here and temperatures dropped 14 degrees during the Friday morning heavy rain event (which yielded snow showers the next morning.) It also forced a redevelopment around the wedge and low offshore and not thru SC like originally expected. In-situ wedge gets established, this one would get forced to redevelop or go under the wedge. Link to comment Share on other sites More sharing options...
UpStateCAD Posted February 13, 2016 Share Posted February 13, 2016 So what's your precip type forecast for Greer area Monday Sent from my SM-G900P using Tapatalk from what I've seen I think it's safe to assume zr or ip at least to start. The question is how long does it stay frozen before it transitions to rain. I have no idea what the answer to that is. Link to comment Share on other sites More sharing options...
MichaelJ Posted February 13, 2016 Share Posted February 13, 2016 Hate to say it but I would toss the GGEM at this point Link to comment Share on other sites More sharing options...
ozmaea Posted February 13, 2016 Share Posted February 13, 2016 from what I've seen I think it's safe to assume zr or ip at least to start. The question is how long does it stay frozen before it transitions to rain. I have no idea what the answer to that is.So you're not thinking any snow at all hmmmSent from my SM-G900P using Tapatalk Link to comment Share on other sites More sharing options...
buckeyefan1 Posted February 13, 2016 Share Posted February 13, 2016 the GFS is so bad, it has to be run at 60z! Seriously, I have thought in 2016, we wouldn't ever see such model confusion. Problem is, this high will not be able to park. Kind of hard to do with a strong surface low around Greenland. On that same note, watch dewpoint depressions today and tomorrow in SC/NC. This airmass should be exceptionally dry and the last major winter storm, the warm front never made it here and temperatures dropped 14 degrees during the Friday morning heavy rain event (which yielded snow showers the next morning.) It also forced a redevelopment around the wedge and low offshore and not thru SC like originally expected. In-situ wedge gets established, this one would get forced to redevelop or go under the wedge. NyQuil has given me dyslexic fingers I agree it's a wait and see here at CAE, but I'd be more concerned if I lived in the upstate. It doesn't look pretty there if the wedge holds Link to comment Share on other sites More sharing options...
UpStateCAD Posted February 13, 2016 Share Posted February 13, 2016 Hate to say it but I would toss the GGEM at this point I'm tending to agree....but what if the 2M temps are 31 instead of 27 for most of the duration.....still not good. Link to comment Share on other sites More sharing options...
WSNC Posted February 13, 2016 Share Posted February 13, 2016 Can someone with access gives us an EPS report after they have their morning coffee? Thanks. It's fairly consistent with prior run and op. Low seems to be trending weaker, which should help hold wedge in longer. Control run is significantly weaker with low compared to last run and more in line with mean. Faster with low movement vs previous run. Control and mean, especially control. I assume since control is not as amped with low. Link to comment Share on other sites More sharing options...
packfan98 Posted February 13, 2016 Share Posted February 13, 2016 It's fairly consistent with prior run and op. Low seems to be trending weaker, which should help hold wedge in longer. Control run is significantly weaker with low compared to last run and more in line with mean. That sounds like it's heading in a more favorable direction. Hopefully we will have a consensus with the track of the low by the 12z runs tomorrow. I have a feeling we will see some surprises with surface temperatures and transition times on Monday. Link to comment Share on other sites More sharing options...
MichaelJ Posted February 13, 2016 Share Posted February 13, 2016 If the lows that were projected to be last night were any indication, the cold is not nearly as strong as progged. Our low was forecast to be 19 and it was 26 so it busted pretty bad. Edited to add that this is either not as cold of air as predicted OR it is a little late coming in. Link to comment Share on other sites More sharing options...
Blue_Ridge_Escarpment Posted February 13, 2016 Share Posted February 13, 2016 12Z suite is rolling. First up.... The North American Model Link to comment Share on other sites More sharing options...
packfan98 Posted February 13, 2016 Share Posted February 13, 2016 If the lows that were projected to be last night were any indication, the cold is not nearly as strong as progged. Our low was forecast to be 19 and it was 26 so it busted pretty bad Not necessarily a bad thing. Slower to move in could mean slower to move out. By tonight, the cold will be firmly established. Link to comment Share on other sites More sharing options...
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