burgertime Posted February 24, 2015 Share Posted February 24, 2015 Still a lot of variation on the outcome of the Wednesday Night event when looking only at the models. We should see things start to come together by the 0z this evening. Images courtesy of Weatherbell Hi-Res NAM looked just as wet to me vs. last nights run for total QPF...not sure why that WX bell map looks the way it does. If anything it's wetter. 00z 6z I think it's about the same as in reality as 6z came in a little wetter for this morning which that accounts for. Link to comment Share on other sites More sharing options...
NavarreDon Posted February 24, 2015 Share Posted February 24, 2015 Part of WPC's take on the system ON DAY 2...THE 12-00Z UKMET AND ECMWF AND 12Z ECMWF ENSEMBLE MEAN SHOW A WELLDEFINED 700 MB WAVE CROSSING THE LOWER MS VALLEY AND THESOUTHEAST/SOUTHERN APPALACHIANS AND TOWARDS THE MID ATLANTICCOAST. SNOW IS EXPECTED TO DEVELOP ACROSS SOUTHEAST AR/NORTHERNMS AS UPPER DIVERGENCE/LOWER CONVERGENCE MAXIMA DEVELOP IN ACOUPLED JET REGION AT 300 MB. THIS COUPLET MOVES ACROSS THESOUTHERN APPALACHIANS/NC/SOUTHERN VA.THIS SYSTEM SHOULD BEGIN TO TAP A SURGE IN LL MOISTURE. THISMOISTURE WILL GET LIFTED OVER A LOW-MID LEVEL FRONT TO PRODUCE ABAND OF SNOW AND MIXED PRECIPITATION TYPES.A DECENT AMOUNT OF SPREAD EXISTS WITH THE GUIDANCE. THE 00Z NAM ISA CLEAR OVER-AMPLIFIED SOLUTION AT 700 MB AND IS THE ONLY MODELWITH A CLOSED LOW IN THE ARKLATEX. THIS RESULTED IN GREATER SNOWAMTS AND THE AXIS EXTENDING FURTHER NORTH THAN THE OTHER MODELS.THE 00Z GFS FORECAST A FLATTER 700 MB WAVE AND THE RESULTANT SNOWAXIS WAS FURTHER SOUTH IN THE SOUTHEAST/SRN APPALACHIANS/NC. LESSWEIGHTING WAS GIVEN TO THE GFS/NAM ...WITH THE 21Z SREF MEANSUPPORTED BY THE ECMWF ENSEMBLE MEAN AS WELL AS THE OPERATIONALECMWF/UKMET RUNS. THE 03Z SREF MEAN AMPLIFIED THE 700 MB WAVE EVENMORE AND MOVED THE QPF AXIS FURTHER NORTH IN THE MID ATLANTIC..SOWE WILL FOLLOW LATER GUIDANCE TO SEE IF THIS TRANSLATES INTO ATREND IN THE MODELS. Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 The ATL folks better lookout, you are starting to get in the range of RGEM's money time. This would be a historic ATL winter storm... Below is the output from the 6z RGEM for ATL. That's 7-9" of snow. Link to comment Share on other sites More sharing options...
RevDodd Posted February 24, 2015 Share Posted February 24, 2015 Question: Since our biggest threat in SE NC is cold, not moisture, any thought that today's snow blanket might help nudge temps down a bit ... or would the resulting drop be inconsequential? Thanks! Link to comment Share on other sites More sharing options...
burgertime Posted February 24, 2015 Share Posted February 24, 2015 To my knowledge the euro did good with today. It was one of the wettest models around here. But I would say I don't think the nam is correct because it's too strong and north with the H5 look. Not even the southern branch happy doc is. Sent from my iPhone Well I should say it didn't do well for this area IRRC but then again I wasn't focused on this storm today. I just remember it being a whiff and yet here I sit with a dusting already and more on the way. I wouldn't discount the NAM (and I'm not saying that cause it jackpots me)...it always does the best with ULL features and 5h ....though RGEM is money these days so it's going to be a battle between those two just IMHO. Link to comment Share on other sites More sharing options...
burgertime Posted February 24, 2015 Share Posted February 24, 2015 Question: Since our biggest threat in SE NC is cold, not moisture, any thought that today's snow blanket might help nudge temps down a bit ... or would the resulting drop be inconsequential? Thanks! Depending on how much lays down it should help. We need a good widespread 2 inches to really drop temps tonight making it that much harder for it to warm tomorrow. If that happens and QPF outputs on models are correct...LOOKOUT! Link to comment Share on other sites More sharing options...
BullCityWx Posted February 24, 2015 Share Posted February 24, 2015 I just heard a forecaster from TWC on WBT in Charlotte say this storm may pass SOUTH OF US. That is borderline criminal negligence. Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 Hi-Res NAM looked just as wet to me vs. last nights run for total QPF...not sure why that WX bell map looks the way it does. If anything it's wetter. 00z 6z I think it's about the same as in reality as 6z came in a little wetter for this morning which that accounts for. He posted the snow depth, not sure why that's off...this is the snow accumulation map. Link to comment Share on other sites More sharing options...
Poimen Posted February 24, 2015 Share Posted February 24, 2015 Past experience says "he who lives by the NAM dies by the NAM." The NAM has 1" qpf west of Ralegih when most, if not all, of the guidance from last night has Raleigh at .5" or less qpf. Until other guidance comes aboard, the NAM should be used with great caution. Link to comment Share on other sites More sharing options...
BullCityWx Posted February 24, 2015 Share Posted February 24, 2015 Past experience says "he who lives by the NAM dies by the NAM." The NAM has 1" qpf west of Ralegih when most, if not all, of the guidance from last night has Raleigh at .5" or less qpf. Until other guidance comes aboard, the NAM should be used with great caution. The NAM did nail this morning though. Link to comment Share on other sites More sharing options...
nchighcountrywx Posted February 24, 2015 Share Posted February 24, 2015 Not true. Take that snowfall map out further than 4 AM on Thursday, and you'll see the totals ramp up across the entire state. The 06Z NAM was incredible for the entire state of NC: See my post. I think we are confusing maps: Total snow (assuming 10:1 ratios) vs Total Snow on the Ground. The NAM Hires is apparently factoring in melting on the ground with surface temperatures above 32 degrees. Overall, be very wary of the high qpf output of the NAM. Don't set yourself up for disappointment. None of us should set ourselves up for disappointment. The NC High Country has had a good 4 to 6 inches so far this morning with a good chance to double that on Wednesday evening.. Prime day for some great skiing either on the slopes or cross country. Come on up and enjoy it. Link to comment Share on other sites More sharing options...
mikepie Posted February 24, 2015 Share Posted February 24, 2015 The ATL folks better lookout, you are starting to get in the range of RGEM's money time. This would be a historic ATL winter storm... Do you know if that is from Hartsfield airport or somewhere else in the metro? Below is the output from the 6z RGEM for ATL. That's 7-9" of snow. Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 Sure am glad I went to bed last night because the 0z GFS/Euro were a debacle. But the 6z GFS looks much better, big improvement with the strength and tilt of the 5h low... IMO....I think you will see something in between the 6z GFS and 6z NAM's. Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 The ATL folks better lookout, you are starting to get in the range of RGEM's money time. This would be a historic ATL winter storm... Do you know if that is from Hartsfield airport or somewhere else in the metro? Below is the output from the 6z RGEM for ATL. That's 7-9" of snow. Not sure, but I suspect city center... Link to comment Share on other sites More sharing options...
deltadog03 Posted February 24, 2015 Share Posted February 24, 2015 Well I should say it didn't do well for this area IRRC but then again I wasn't focused on this storm today. I just remember it being a whiff and yet here I sit with a dusting already and more on the way. I wouldn't discount the NAM (and I'm not saying that cause it jackpots me)...it always does the best with ULL features and 5h ....though RGEM is money these days so it's going to be a battle between those two just IMHO.Oh I hear Ya. I just want to see another model or 2 at least show the H5 look stronger. NAM on its on with that. Hence its further north. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
packfan98 Posted February 24, 2015 Share Posted February 24, 2015 Brad Panovich's call map: Link to comment Share on other sites More sharing options...
Tacoma Posted February 24, 2015 Share Posted February 24, 2015 Not true. Take that snowfall map out further than 4 AM on Thursday, and you'll see the totals ramp up across the entire state. The 06Z NAM was incredible for the entire state of NC: wow looks like the whole state of NC, ETN, N.GA., upstate SC and S. VA. could be widespread 6-10 Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 Brad Panovich's call map: Wow, looks like he bumped that up big time, after just the NAM/SREF output I would guess. Impressive. Latest SREF mean snowfall map, bumped up over previous runs too. Link to comment Share on other sites More sharing options...
franklin NCwx Posted February 24, 2015 Share Posted February 24, 2015 So what's wrong with the nam at 5h? Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 See my post. I think we are confusing maps: Total snow (assuming 10:1 ratios) vs Total Snow on the Ground. The NAM Hires is apparently factoring in melting on the ground with surface temperatures above 32 degrees. Overall, be very wary of the high qpf output of the NAM. Don't set yourself up for disappointment. You are right, the snow depth does factor in melting, about a useful a map as the snow total map, LOL. I would think/hope most people know to cut NAM by 30-40% by now. Link to comment Share on other sites More sharing options...
audioguy3107 Posted February 24, 2015 Share Posted February 24, 2015 Interesting discussion out of BHM this morning.......they're going with a blend of the NAM/SREF/ and EURO.....they feel the NAM is over amped as well but can't discount it either. Calling for the heaviest snows to be along I-20 and north reaching over toward Anniston. Don't want to weenie out. But looks like here in the northern Atlanta suburbs we're really in the jackpot zone. - Buck Link to comment Share on other sites More sharing options...
burgertime Posted February 24, 2015 Share Posted February 24, 2015 So what's wrong with the nam at 5h?Chris thinks it's too wrapped and slow thus pushing everything too far north. So far it's the only guidance really doing that. Link to comment Share on other sites More sharing options...
VARTV Posted February 24, 2015 Share Posted February 24, 2015 Turned on the tv and WRAL is still glazing over the topic of wed/thur. It's like they are "let's just talk about xyz so maybe they won't notice the snow flake graphic and we can be non committal longer" forget all the overnight models. Lol NBC station (WAVY) in SEVA said something similar... glazed over Thursday's potential event and said let's focus on today's light snow... Link to comment Share on other sites More sharing options...
Brick Tamland Posted February 24, 2015 Share Posted February 24, 2015 Looks like the other models are going more towards the NAM than the GFS. Link to comment Share on other sites More sharing options...
packbacker Posted February 24, 2015 Share Posted February 24, 2015 Chris thinks it's too wrapped and slow thus pushing everything too far north. So far it's the only guidance really doing that. The NAM's do have some skill once inside 36 hours, granted always take the QPF output with a grain of salt but they are keeping the ULL closed off longer each run, it's still closed off at 39 hours of both models on the 6z runs. The 6z GFS did trend stronger, noticeable stronger, I think we will get some insight in a couple of hours on whether the NAM's are off there rocker, but I would suspect they will meet somewhere in the middle SLP track wise. We all know the NAM is like a firehose with QPF so we slash that. Link to comment Share on other sites More sharing options...
franklin NCwx Posted February 24, 2015 Share Posted February 24, 2015 Chris thinks it's too wrapped and slow thus pushing everything too far north. So far it's the only guidance really doing that.it could be, but how much? Most of the sref members agree with the nam. This is what the shorter higher resolution model's are For. In reality the nam and sref is not too far off the 12z Sunday run of the euro and the recent ukie runs. Link to comment Share on other sites More sharing options...
calculus1 Posted February 24, 2015 Share Posted February 24, 2015 See my post. I think we are confusing maps: Total snow (assuming 10:1 ratios) vs Total Snow on the Ground. The NAM Hires is apparently factoring in melting on the ground with surface temperatures above 32 degrees. Overall, be very wary of the high qpf output of the NAM. Don't set yourself up for disappointment. I think you have me confused with somebody else. I'm one of the least emotional posters on this board. I know better than to get too overly-enthused by a single run of computer-generated weather model. However, I also don't try to find the single piece of coal in an otherwise gorgeous field of diamonds. Link to comment Share on other sites More sharing options...
franklin NCwx Posted February 24, 2015 Share Posted February 24, 2015 The NAM's do have some skill once inside 36 hours, granted always take the QPF output with a grain of salt but they are keeping the ULL closed off longer each run, it's still closed off at 39 hours of both models on the 6z runs. The 6z GFS did trend stronger, noticeable stronger, I think we will get some insight in a couple of hours on whether the NAM's are off there rocker, but I would suspect they will meet somewhere in the middle SLP track wise. We all know the NAM is like a firehose with QPF so we slash that.this! We all know the qpf on the nam is usually overdone, but it's the handling of the upper level energy that I like to look at. Along with the orientation of the trough. Link to comment Share on other sites More sharing options...
Met1985 Posted February 24, 2015 Share Posted February 24, 2015 He posted the snow depth, not sure why that's off...this is the snow accumulation map.that's impressive for a lot of the viewing area for sure. Link to comment Share on other sites More sharing options...
Wow Posted February 24, 2015 Author Share Posted February 24, 2015 Brad Panovich's call map: Wow, he really did bump up his ideas fast. Looks reasonable given the model output this morning. We've got a nice blanket of snowfall and currently snowing. 1-2".. that'll keep the ground cool! Link to comment Share on other sites More sharing options...
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