Upstate Tiger Posted January 22 Share Posted January 22 There's been some talk about the correlation and timing of cold in the SE to winter storms. Just for fun, I went back and looked at some memorable winter storms to see what temps looked like in the days leading up to these storms. This is for the Greenville, SC area. The far right column is new snow depth. With the exception of 1982, the cold air arrives within 24 hours of the onset of the storm. February 2014 January 2011 February 2004 January 1996 March 1993 January 1988 January 1987 January 1982 March 1980 February 1979 6 2 Link to comment Share on other sites More sharing options...
GaWx Posted January 22 Share Posted January 22 1 hour ago, Upstate Tiger said: There's been some talk about the correlation and timing of cold in the SE to winter storms. Just for fun, I went back and looked at some memorable winter storms to see what temps looked like in the days leading up to these storms. This is for the Greenville, SC area. The far right column is new snow depth. With the exception of 1982, the cold air arrives within 24 hours of the onset of the storm. February 2014 January 2011 February 2004 January 1996 March 1993 January 1988 January 1987 January 1982 March 1980 February 1979 Very interesting post as it is backed by a good sized sample of real data. The results makes sense because USUALLY the cold needs to get there in advance for a BIG snow as opposed to the cold chasing moisture/rain change to snow scenario for which usually it dries out too quickly. But this also shows that it is best that the cold not come in too far in advance or else there’s a rapidly increasing staleness risk since cold in the SE usually modifies quickly/850s rise above 0C. Because 1982 was so extremely cold in advance, it had an extra day or so of time before 850s got too warm for snow. 3 Link to comment Share on other sites More sharing options...
tarheelwx Posted January 22 Share Posted January 22 Stark changes in the 12z GFS eh? TW Link to comment Share on other sites More sharing options...
GaWx Posted January 22 Share Posted January 22 17 minutes ago, tarheelwx said: Stark changes in the 12z GFS eh? TW Indeed. After getting mild, the 12Z GFS has no warmth for over a full week, Jan 29-Feb 5+. Plus a wedge may follow. That would be longer than the mild ~5 days preceding it. Of course, fwiw since it is the wild swinging op GFS. 3 Link to comment Share on other sites More sharing options...
NorthHillsWx Posted January 22 Share Posted January 22 Well the idea of 3 weeks of solid warmth is getting derailed at least in the ops. Canadian actually first to pick up on the cooler first week of Feb (it’s backed off somewhat). GFS has trended way colder 3 Link to comment Share on other sites More sharing options...
tarheelwx Posted January 22 Share Posted January 22 Just goes to show that early February is not set in stone in any way shape or form as of yet. TW 3 Link to comment Share on other sites More sharing options...
GaWx Posted January 22 Share Posted January 22 29 minutes ago, NorthHillsWx said: Well the idea of 3 weeks of solid warmth is getting derailed at least in the ops. Canadian actually first to pick up on the cooler first week of Feb (it’s backed off somewhat). GFS has trended way colder There's been a short break in the mild pattern in the SE that has been suggested for a good number of days of runs for near the end of Jan/start of Feb in between mild periods lasting ~one week prior and one week+ afterward. So, the earlier idea of 3 weeks in a row of solid warmth was exaggerated by whomever was saying that imo. But the 12Z GFS has only ~5 days of warmth on the entire run...a pretty significant outlier vs other runs. Though not betting on it, I hope it happens. Keep the warmth away as much as possible as we have enough of it at other times of year. 4 Link to comment Share on other sites More sharing options...
GaWx Posted January 22 Share Posted January 22 Even though the 12Z GEFS doesn't have the cold of the 12Z GFS, even it has a period of pretty close to normal in much of the SE US Jan 29-Feb 2. So, a break in the warmth over most of the SE is quite likely around then, whether it includes actual BN cold or not. I’d actually bet on a couple of BN days for many as ensemble means smooth out daily anomalies due to timing differences of members. 2 Link to comment Share on other sites More sharing options...
Brick Tamland Posted January 22 Share Posted January 22 I'm sure we'll get cold again in February after the warm up this week. I just don't think we'll have any precip to go along with it when it's cold enough for snow. It's been the same thing the last few winters. Cold and dry, warms up and rains, drys out in time for it to get cold again. Until that doesn't happen I don't see any reason to believe it's going to be any different in regards to snow chances in NC outside the mountains, and especially for the Triangle and east. 1 1 2 Link to comment Share on other sites More sharing options...
GaWx Posted January 22 Share Posted January 22 The latest 48 member CFS ens (4 member x 12 runs through 6Z on 1/22) stays the course for most of Feb in the SE with a -AO, Aleutian trough/+PNA, BN H5 hts, and a wet Gulf low favoring subtropical flow (split flow in combo with the +PNA) all combining for plenty of potential for especially mid Feb through early Mar. This run actually lowers H5 earlier. 4 1 Link to comment Share on other sites More sharing options...
BooneWX Posted January 22 Share Posted January 22 Weather really does have a memory it seems. In December we were given this exact picture of a death ridge that would rule for 3+ weeks and it ended up being slightly above normal at best with some legitimately warmer days on the front end like this week. The upcoming pattern screams opportunities for CAD and progressive cold shots. It won’t be an ideal pattern for winter weather but when is it ever? 3 Link to comment Share on other sites More sharing options...
Met1985 Posted January 22 Share Posted January 22 1 hour ago, BooneWX said: Weather really does have a memory it seems. In December we were given this exact picture of a death ridge that would rule for 3+ weeks and it ended up being slightly above normal at best with some legitimately warmer days on the front end like this week. The upcoming pattern screams opportunities for CAD and progressive cold shots. It won’t be an ideal pattern for winter weather but when is it ever? We've been being preached that we are going to torch for a whole month that never came to fruition. I've talked about pattern recognition with carversgap and Larry on here a couple of times. Sure we will warm up but after the cold We've seen in my opinion that is pretty normal. 8 Link to comment Share on other sites More sharing options...
GaWx Posted January 22 Share Posted January 22 6 hours ago, tarheelwx said: Stark changes in the 12z GFS eh? TW 18Z GFS, like the 12Z, also has only ~5 truly mild to warm days in the bulk of the SE through the entire run. As a bonus, it like the 12Z has generous (~3-5”) upslope snow in W NC along the TN border. 4 1 Link to comment Share on other sites More sharing options...
tarheelwx Posted January 23 Share Posted January 23 2 hours ago, GaWx said: 18Z GFS, like the 12Z, also has only ~5 truly mild to warm days in the bulk of the SE through the entire run. As a bonus, it like the 12Z has generous (~3-5”) upslope snow in W NC along the TN border. What had looked like a long term major thaw now looks like a run of the mill thaw. No guarantees yet thought. TW 1 1 Link to comment Share on other sites More sharing options...
GaWx Posted January 23 Share Posted January 23 Is this good? To give an idea of how much extra moisture this represents thanks to the subtropical jet, @pcbjr’s abode of Hogtown, FL, is shown getting almost double its normal rainfall for Feb 13-19. Normal is 0.64” and this suggests ~1.20” of qpf along with cold air lurking to the north. It suggests ~1.25” at ATL since normals are much higher there and in other areas of the heart of the SE. The qpf in most of the SE is 1”+. Split flow ftw? At least the ducks are on the pond and it’s mid-Feb during El Niño. Get the right timed mix and look out SE. 2 Link to comment Share on other sites More sharing options...
olafminesaw Posted January 23 Share Posted January 23 Let's see if this one gains any traction. Not a typical system in our area, almost like a clipper 2 Link to comment Share on other sites More sharing options...
JoshM Posted January 23 Share Posted January 23 Now that the cold is gone, back to the monsoon. You just can't make this shit up 1 3 1 Link to comment Share on other sites More sharing options...
GaWx Posted January 23 Share Posted January 23 16 hours ago, tarheelwx said: What had looked like a long term major thaw now looks like a run of the mill thaw. No guarantees yet thought. TW 12Z GFS still has only 6 mild to warm afternoons in NC: Jan 24-28 and Feb 2 out of 16 days. Also, 4 afternoons are actually cold. And this is well before the modeled/supposed good stuff starts after Feb 10, which hopefully would start showing up near the end of the 15-16 day ensemble runs by this weekend. That’s been the timeframe for that for many days. I’ve been posting about this extended model based potential for ~10 days. No slippage yet. 3 Link to comment Share on other sites More sharing options...
Tacoma Posted January 23 Share Posted January 23 1 hour ago, GaWx said: 12Z GFS still has only 6 mild to warm afternoons in NC: Jan 24-28 and Feb 2 out of 16 days. Also, 4 afternoons are actually cold. And this is well before the modeled/supposed good stuff starts after Feb 10, which hopefully would start showing up near the end of the 15-16 day ensemble runs by this weekend. That’s been the timeframe for that for many days. I’ve been posting about this extended model based potential for ~10 days. No slippage yet. I enjoy reading your thoughts my friend, keep up the good work. Very interesting stuff every time I read your thoughts and research. Come on snow. 2 2 Link to comment Share on other sites More sharing options...
GaWx Posted January 23 Share Posted January 23 30 minutes ago, Tacoma said: I enjoy reading your thoughts my friend, keep up the good work. Very interesting stuff every time I read your thoughts and research. Come on snow. Thank you! Where can I sign up for this that just came out from the newest 48 CFS run mean for mid Feb (Feb 13-19)? It has -EPO, +PNA, -AO, -NAO, and the very important and sometimes overlooked split flow (moist subtropical jet underneath and overrunning the bottom of the cold air supply from +PNA) with a good moisture source coming across from Baja CA. This pattern should it materialize would favor any Arctic high to move from the N Plains to near the Ohio Valley as opposed to the colder but drier option of plunging down into the S Plains. What more could one want in terms of overall pattern for SE winter storm potential other than needing to be patient since it would take ~3 weeks to get established? By the way, that timeframe continues to move up as it was 4+ weeks away when I first started seeing it on the extended models over a week ago. 2 1 2 Link to comment Share on other sites More sharing options...
Met1985 Posted January 23 Share Posted January 23 43 minutes ago, GaWx said: Thank you! Where can I sign up for this that just came out from the newest 48 CFS run mean for mid Feb (Feb 13-19)? It has -EPO, +PNA, -AO, -NAO, and the very important and sometimes overlooked split flow (moist subtropical jet underneath and overrunning the bottom of the cold air supply from +PNA) with a good moisture source coming across from Baja CA. This pattern should it materialize would favor any Arctic high to move from the N Plains to near the Ohio Valley as opposed to the colder but drier option of plunging down into the S Plains. What more could one want in terms of overall pattern for SE winter storm potential other than needing to be patient since it would take ~3 weeks to get established? By the way, that timeframe continues to move up as it was 4+ weeks away when I first started seeing it on the extended models over a week ago. Let's do it! 1 Link to comment Share on other sites More sharing options...
eyewall Posted January 23 Share Posted January 23 10 hours ago, olafminesaw said: Let's see if this one gains any traction. Not a typical system in our area, almost like a clipper And it's gone. 1 2 Link to comment Share on other sites More sharing options...
PackGrad05 Posted January 23 Share Posted January 23 35 minutes ago, eyewall said: And it's gone. Worth mentioning that the 00Z EPS showed zilch for that time period. However, the 12Z actually had a few members show something... Grasping at straws, but at least something to watch...until dreams are crushed again. 1 1 Link to comment Share on other sites More sharing options...
Coach McGuirk Posted January 24 Share Posted January 24 This feels like last winter. Everything is a week away. In this case, 2 weeks away. Link to comment Share on other sites More sharing options...
GaWx Posted January 24 Share Posted January 24 The just released extended GEFS is as cold as any run yet for mid to late Feb in the SE and much of the E and C US for that matter. For example, this is very impressive cold for an ensemble mean of 31 members way out on day 27 with these 850 mb anomalies as cold as -7C/-13F! Looking at individual members and considering the degree of cold and the pattern, this run has two main periods that suggest a significantly enhanced chance vs climo for a GOM Miller A/widespread major SE winter storm, Feb 18-19 and Feb 23-24: The exact dates aren’t important as they’ll change with each run. What’s important is the pattern showing up for mid to late Feb on the various extended models for ~10 days of runs now. Not only are they not backing down, the start of the pattern change is gradually moving earlier. This run has the +PNA starting to get reestablished ~Feb 8th. The run from 5 days earlier didn’t have the +PNA getting going til ~Feb 13. But also, the cold signal is generally getting stronger as we get closer. 3 2 3 Link to comment Share on other sites More sharing options...
Leesville Wx Hawk Posted January 24 Share Posted January 24 It’s looking like there will be something to watch moving forward.. Link to comment Share on other sites More sharing options...
wncsnow Posted January 24 Share Posted January 24 Even at day 10 there is no cold at all in Canada. It's going to take a while for any pattern change. Likely post Valentines day if it happens at all. 2 1 Link to comment Share on other sites More sharing options...
Met1985 Posted January 24 Share Posted January 24 Euro Weeklies and the eps, and the GEFS all look good for a return to a more stable winter pattern around the 8th of February. The Weeklies look really good from the 2nd week of February all the way to the first of March. We are looking at the bigger picture here not individual storms at this point. 3 Link to comment Share on other sites More sharing options...
wncsnow Posted January 24 Share Posted January 24 59 minutes ago, Met1985 said: Euro Weeklies and the eps, and the GEFS all look good for a return to a more stable winter pattern around the 8th of February. The Weeklies look really good from the 2nd week of February all the way to the first of March. We are looking at the bigger picture here not individual storms at this point. The big picture says wait at least 3 weeks 1 Link to comment Share on other sites More sharing options...
wncsnow Posted January 24 Share Posted January 24 1 hour ago, Met1985 said: Euro Weeklies and the eps, and the GEFS all look good for a return to a more stable winter pattern around the 8th of February. The Weeklies look really good from the 2nd week of February all the way to the first of March. We are looking at the bigger picture here not individual storms at this point. The weeklies also showed the whole month of January being great into February at one point. We all see how that turned out. One week of cold temperatures and some snow in the mountains 1 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now