SnowNiner Posted January 8, 2019 Share Posted January 8, 2019 1 hour ago, Cold Rain said: RAH sounds really bullish this far out. Really good discussion. There remains little to no change in forecast rationale from 24 hrs ago, with average to above average forecast confidence in the overall pattern, but below average confidence in details. The middle Atlantic states will be firmly influenced by cold, continental polar high pressure extending from the upr Midwest to the Carolinas through the end of the week. 850 mb temperatures trailing a pair of polar fronts that will cross cntl NC tonight and Wednesday are forecast to nadir around minus 11-12 at GSO by 12Z Thu. Related cold air advection will support a strong nwly breeze, amidst a deeply mixed boundary layer, even nocturnally Wed night, with wind chill values in the teens through late morning Thu. Although the wind will subside by Thu night, the presence of a "break-off", 1030 mb surface high over the wrn Carolinas Fri morning will support colder air temperatures - mostly between 20 and 25 degrees. High temperatures will be similarly chilly, in the upr 30s to mid 40s Thu and perhaps a 2-3 degrees less cold on Fri. While the aforementioned mid-upr low/trough will lift newd and away from the nern US through the end of the week, renewed nrn stream amplification, with a few distinct shortwave troughs embedded within, is forecast to occur from cntl Canada to the cntl Appalachians Fri-Mon. At the same time, a srn stream shortwave trough is forecast to migrate across the srn US, likely immediately preceding the nrn stream troughs (ie. slightly out of phase), through Sat-Sat night. None of those features, most borne from the large, deep cyclone over the ern/e-cntl N. Pacific this morning, are not forecast to reach the NOAM rawinsonde network until 12Z Thu; and it will likely be the 00Z Fri NWP runs that provide a marked boost in model agreement and forecast confidence - after those features will have been sampled twice by the upr air network (12Z Thu and 00Z Fri), and previous model run initialization influences been dampened by hopefully "better" data. Further complicating the forecast by D6-7 --and possible continuation of large scale ascent, deformation, precipitation production over the middle Atlantic states-- will be the degree of Arctic stream amplification across the sern Canada/Great Lakes/Northeast vicinity, as well as the ejection of additional srn stream energy beneath a developing Rex block over the wrn CONUS. Despite those complexities and details, the overall pattern will be one supportive of cyclogenesis from the GOM to the middle Atlantic coast, with a track and intensity close to the preferred GEFS and EPS means. Specifically, such a solution is unlike the wrn outlier 00Z/8th deterministic GFS track, which favors an inland track through ern NC and warmer solution for cntl NC; and it is closer to the 00Z/8th deterministic ECMWF track (ie. more offshore and colder for cntl NC), and stronger. Additionally strong confluence aloft over the nrn middle Atlantic states and Northeast, though to varying degrees given the uncertainties aloft described above, will favor a well-positioned, and strong, cold high extending across the middle Atlantic states - one that will provide sufficient cold air to support measurable snow across parts of the middle Atlantic Piedmont, including probably the climatologically-favored nrn and wrn NC Piedmont, from late Sat-early Sun, and potentially longer. I liked the fact that they preferred the ensembles track, rather than the constant GFS/FV3 inland track. That's huge imo. I'm not bought into this yet, as GSP is not bullish, says it's a mixed bag Miller B that changes everybody to rain Saturday night and Sunday. That wouldn't be the case though I don't think if the ensembles track is correct. 2 Link to comment Share on other sites More sharing options...
CaryWx Posted January 8, 2019 Share Posted January 8, 2019 Where's that 850 line ajr refers to lining up? Link to comment Share on other sites More sharing options...
ajr Posted January 8, 2019 Share Posted January 8, 2019 1 minute ago, CaryWx said: Where's that 850 line ajr refers to lining up? Verbatim looks to be around the northern border counties on the GFS -- obviously it's going to move around a bunch the next few days Link to comment Share on other sites More sharing options...
CaryWx Posted January 8, 2019 Share Posted January 8, 2019 The GFS ensembles look like they have a stronger HP at 1040. That's stout if it verifies. Didn't most of the other guidance have it 1034-1038 or so? Link to comment Share on other sites More sharing options...
griteater Posted January 8, 2019 Share Posted January 8, 2019 16 minutes ago, SnowNiner said: I liked the fact that they preferred the ensembles track, rather than the constant GFS/FV3 inland track. That's huge imo. I'm not bought into this yet, as GSP is not bullish, says it's a mixed bag Miller B that changes everybody to rain Saturday night and Sunday. That wouldn't be the case though I don't think if the ensembles track is correct. The Greenville NWS "changes everybody to rain" wording is a bunch of bunk IMO, especially for the hardcore CAD areas in the foothills. Yeah, Raleigh NWS is going with more of a Miller A with mostly snow where temps allow and Greenville NWS is going with the Miller A/B Hybrid, mixed bag scenario. I favor the mixed bag scenario, but not "changing to rain in all areas". 2 1 Link to comment Share on other sites More sharing options...
sarcean Posted January 8, 2019 Share Posted January 8, 2019 7 minutes ago, griteater said: The Greenville NWS "changes everybody to rain" wording is a bunch of bunk IMO, especially for the hardcore CAD areas in the foothills. Yeah, Raleigh NWS is going with more of a Miller A with mostly snow where temps allow and Greenville NWS is going with the Miller A/B Hybrid, mixed bag scenario. I favor the mixed bag scenario, but not "changing to rain in all areas". Correct me if I'm wrong but Raleigh is normally quite conservative to call for snow so I think its big they are so bullish on this storm so far Link to comment Share on other sites More sharing options...
BullCityWx Posted January 8, 2019 Share Posted January 8, 2019 6z EPS run looks significantly better than 0z. 2" mean line moved about 100 miles east. 2 Link to comment Share on other sites More sharing options...
CentralNC Posted January 8, 2019 Share Posted January 8, 2019 2 minutes ago, sarcean said: Correct me if I'm wrong but Raleigh is normally quite conservative to call for snow so I think its big they are so bullish on this storm so far Yeah the last time GSP was more bullish so it's the other way around this time. Go figure. 1 Link to comment Share on other sites More sharing options...
griteater Posted January 8, 2019 Share Posted January 8, 2019 Both NWS offices have become more apt to be bullish in the extended range over the years. Not sure why that is, but in the old days, they were typically conservative until it got close in. 1 Link to comment Share on other sites More sharing options...
tarheelwx Posted January 8, 2019 Share Posted January 8, 2019 FWIW. In the past, RAH was always very conservative early in the season, but once we had a good storm they’d be much less conservative the remainder of the season. Kind of like getting a kid to jump off the diving board the first time......it was hard but each time became a little easier unless there was a disappointing bust along the way. For whatever reason, the more bullish attitude regarding winter weather resets over the summer. TW 1 1 Link to comment Share on other sites More sharing options...
BullCityWx Posted January 8, 2019 Share Posted January 8, 2019 I think the 6z ICON would’ve been a good run if it had ran out through the duration. It was snowing in Charlotte and Greenville at 120. Link to comment Share on other sites More sharing options...
kvegas-wx Posted January 8, 2019 Share Posted January 8, 2019 4-5 days out. Time for @OrangeburgWX to see if he can go 2-2 with storm threads this season. Reel it in! Link to comment Share on other sites More sharing options...
Blue_Ridge_Escarpment Posted January 8, 2019 Share Posted January 8, 2019 8 minutes ago, Queencitywx said: I think the 6z ICON would’ve been a good run if it had ran out through the duration. It was snowing in Charlotte and Greenville at 120. Out to 90 on 12Z ICON it’s colder and low further south. Link to comment Share on other sites More sharing options...
BornAgain13 Posted January 8, 2019 Share Posted January 8, 2019 12z ICON looks like it's coming in with the goods! Link to comment Share on other sites More sharing options...
HKY_WX Posted January 8, 2019 Share Posted January 8, 2019 I posted an update for anyone interested... https://m.facebook.com/TheHuffmanbarometer 4 1 Link to comment Share on other sites More sharing options...
Jonathan Posted January 8, 2019 Share Posted January 8, 2019 4 minutes ago, HKY_WX said: I posted an update for anyone interested... https://m.facebook.com/TheHuffmanbarometer Brandon do you think north of I-40 has a decent shot to stay all snow or do we mix? Would really love to see another Miller A but a B/hybrid would mix a lot of folks. Also, both GFS models continue bringing the goods with southern storm after southern storm and big Canadian HPs dropping down every few days. Fun times ahead? Link to comment Share on other sites More sharing options...
Jonathan Posted January 8, 2019 Share Posted January 8, 2019 The ICON HAS to be too warm with a 1040-1041 HP in a beautiful spot. 32F line runs right along the VA/NC border. It has this problem with the December storm too, IIRC. Link to comment Share on other sites More sharing options...
BullCityWx Posted January 8, 2019 Share Posted January 8, 2019 Someone smarter than me can speak on this but I swear I remember hearing there's something about the ICON's resolution that doesnt do well with CAD. Link to comment Share on other sites More sharing options...
BornAgain13 Posted January 8, 2019 Share Posted January 8, 2019 12z GFS looks like it will be a little further north from 6z ... looks stronger. Link to comment Share on other sites More sharing options...
ajr Posted January 8, 2019 Share Posted January 8, 2019 Just now, BornAgain13 said: 12z GFS looks like it will be a little further north from 6z ... looks stronger. Earlier phase too it looks like - MA should be happy Link to comment Share on other sites More sharing options...
mackerel_sky Posted January 8, 2019 Share Posted January 8, 2019 10 minutes ago, ajr said: Earlier phase too it looks like - MA should be happy ???? Looks good to me, low S of 6z run! 1 Link to comment Share on other sites More sharing options...
SouthWake33 Posted January 8, 2019 Share Posted January 8, 2019 9 minutes ago, ajr said: Earlier phase too it looks like - MA should be happy Mostly noise...result is fairly similar to 6z for most. HP is slightly weaker. Link to comment Share on other sites More sharing options...
griteater Posted January 8, 2019 Share Posted January 8, 2019 Yeah GFS run was similar...it was a little warmer in the E Piedmont Canadian was colder at the sfc with freezing rain down into SC Link to comment Share on other sites More sharing options...
SnowNiner Posted January 8, 2019 Share Posted January 8, 2019 1 hour ago, griteater said: The Greenville NWS "changes everybody to rain" wording is a bunch of bunk IMO, especially for the hardcore CAD areas in the foothills. Yeah, Raleigh NWS is going with more of a Miller A with mostly snow where temps allow and Greenville NWS is going with the Miller A/B Hybrid, mixed bag scenario. I favor the mixed bag scenario, but not "changing to rain in all areas". It's strange, both the ensembles look they have this rolling south along the gulf coast. Seems like we always get the A/B hybrid no matter what nowadays. Link to comment Share on other sites More sharing options...
griteater Posted January 8, 2019 Share Posted January 8, 2019 6 minutes ago, SnowNiner said: It's strange, both the ensembles look they have this rolling south along the gulf coast. Seems like we always get the A/B hybrid no matter what nowadays. Just don't have enough well-entrenched cold air to the south. We want to see both Tennessee and North Carolina full of cold air prior to the storm as opposed to cold air retreating in TN and hanging on via cold air damming in NC as the storm approaches. Cold air damming is great to have, just need it cold in TN prior to the storm as well for more snow. 3 Link to comment Share on other sites More sharing options...
Orangeburgwx Posted January 8, 2019 Share Posted January 8, 2019 3 hours ago, FallsLake said: Might be time for a dedicated thread..... but I know nobody wants to jinx it. Well I made it last month and it turned out just fine Link to comment Share on other sites More sharing options...
Orangeburgwx Posted January 8, 2019 Share Posted January 8, 2019 1 hour ago, kvegas-wx said: 4-5 days out. Time for @OrangeburgWX to see if he can go 2-2 with storm threads this season. Reel it in! I am soooooo tempted... Link to comment Share on other sites More sharing options...
FallsLake Posted January 8, 2019 Share Posted January 8, 2019 1 minute ago, Orangeburgwx said: Well I made it last month and it turned out just fine It's time. Do it. We wont blame you on the outcome. Link to comment Share on other sites More sharing options...
Orangeburgwx Posted January 8, 2019 Share Posted January 8, 2019 4 hours ago, FallsLake said: No its fine, and you're right they're bullish. Might be time for a dedicated thread..... but I know nobody wants to jinx it. 1 hour ago, kvegas-wx said: 4-5 days out. Time for @OrangeburgWX to see if he can go 2-2 with storm threads this season. Reel it in! Thread made 1 Link to comment Share on other sites More sharing options...
The Alchemist Posted January 8, 2019 Share Posted January 8, 2019 Could any of the mods or red taggers comment on the government shutdown and if the GFS is getting the full current observational data input prior to each model run? Edit - Saw someone post in the mountain thread last night, that they thought the shutdown was affecting it, but don't really see where the would be the case... Link to comment Share on other sites More sharing options...
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