downeastnc Posted January 25, 2014 Share Posted January 25, 2014 ggemens.JPG pretty impressive for an ens mean Looks good and its been fairly consistent with this slow west trend of the moisture....... 1.25" QPF with 15-20:1 ratios Link to comment Share on other sites More sharing options...
superjames1992 Posted January 25, 2014 Share Posted January 25, 2014 Are the GGEM Ensembles totally out to lunch or are they on to something? It's hard to believe because they seem to be getting wetter with each successive run. Perhaps the GGEM op's coming up short at 12z was just a blip? That's pretty crazy to see those kind of amounts from an ensemble mean, and it's even pretty good all the way to the foothills, with 0.50" just a stone's throw away from the Triad. The amounts for E NC are just insane. BTW, the Euro's ensemble mean at 12z shows about 1" of snow for GSO, 2" for RDU, 1" at CLT, 4" at ILM, and around 3.5" at PGV. That's all using 10:1 ratios, so in reality you're probably looking at higher totals. Note the operational showed nothing at any of those locations (except a little at ILM). Link to comment Share on other sites More sharing options...
packbacker Posted January 25, 2014 Share Posted January 25, 2014 Allan just tweeted, key data pieces get sampled for tomorrow's runs. Link to comment Share on other sites More sharing options...
dsaur Posted January 25, 2014 Share Posted January 25, 2014 Larry, Delta? Does Macon have an archive containing winter storm data? Just curious how often a situation like this will give Macon frozen precip where Atl gets none, or little. As I recall it's not so uncommon...maybe once in 10 years central Ga will get a hit? Once in 15? Most often light to light/moderate. Tony Link to comment Share on other sites More sharing options...
senc30 Posted January 25, 2014 Share Posted January 25, 2014 It is mostly referring to far inland because most members live there. The coastal rep. is decent but seemingly quiet only because the numbers are much smaller. Where do you live? SE NC within 50 of coast? I live about 30-35 miles west of topsail beach. Thanks for the response! Link to comment Share on other sites More sharing options...
HWY316wx Posted January 25, 2014 Share Posted January 25, 2014 Allan just tweeted, key data pieces get sampled for tomorrow's runs. I will follow that up with him saying he is leaning towards and Eastern Carolinas / GA solution. Link to comment Share on other sites More sharing options...
Disco-lemonade Posted January 25, 2014 Share Posted January 25, 2014 Allan just tweeted, key data pieces get sampled for tomorrow's runs. Is that going to start with tonights 0zs? Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 25, 2014 Share Posted January 25, 2014 Looks like to me that the problem with the 18Z GFs is that the timing of the northern vort and southern stream is not quite there, and when it occurs, it occurs too late. Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 25, 2014 Share Posted January 25, 2014 Not to mention stuff is left hanging back SW... Link to comment Share on other sites More sharing options...
GaWx Posted January 25, 2014 Author Share Posted January 25, 2014 Larry, Delta? Does Macon have an archive containing winter storm data? Just curious how often a situation like this will give Macon frozen precip where Atl gets none, or little. As I recall it's not so uncommon...maybe once in 10 years central Ga will get a hit? Once in 15? Most often light to light/moderate. Tony I don't keep any data for Macon. However, I do know that they got hit pretty hard with ~7" of snow (2nd biggest on record I think) heavier toward Augusta) on 2/25/1914 from 0.66" of liquid. ATL got 2.5-3" of snow from ~0.20"...high ratios? SAV got only a tiny bit of snow followed by some IP and then a major/damaging ZR from a grand total of ~1.20" of precip. Their high was only 33. I do think that 2/25/1914 may be a good analog to study for the upcoming threat. IF SAV/CHs get mainly ZR/IP, then that and other analogs suggest that there'd likely be 1"+ S back at least to ATL. (Of course, we know about 2/1973. But SAV mainly got snow from that.) Link to comment Share on other sites More sharing options...
Wow Posted January 25, 2014 Share Posted January 25, 2014 18z GFS crapped out and held the southern s/w way back and cut it off from the main flow. The NAM continues to be progressive with it, travelling well south into Mexico, drawing up a sfc low deep from the GOM. If the polar s/w does come into far west enough to phase into it, the jet ahead of it will turn more southerly and and precip field will blossom over the SE. Link to comment Share on other sites More sharing options...
dsaur Posted January 25, 2014 Share Posted January 25, 2014 I don't keep any data for Macon. However, I do know that they got hit pretty hard with ~7" of snow (heavier toward Augusta) on 2/25/1914. ATL got 3" of snow. SAV got only a tiny bit of snow followed by some IP and then a major/damaging ZR from a grand total of ~1.20" of precip. Their high was only 33. I do think that 2/25/1914 may be a good analog to study for the upcoming threat. IF SAV/CHs get mainly ZR/IP, then that and other analogs suggest that there'd likely be 1"+ back at least ton ATL. (Of course, we know about 2/1973.) Thanks, Doc feel good. Remind me about zrain It's cold enough up here to where if this is a weak wandering up and down the state of some weak impulses along the coast, I'll see sn/sleet, thank you very much, lol. If there is more moisture, and a strong enough push up the state, it sure looks like it could be a zrain/ip deal for some if it's a storm with a warm tongue, and it's prime climo time for it. The op majors make you think it's probably a nuisance event, but the members make you think is probably going to be more. Fun to watch, for central and south Ga. and SC. T Link to comment Share on other sites More sharing options...
Jon Posted January 25, 2014 Share Posted January 25, 2014 Comparing the 0z Euro (hr 78) v/s 12z Euro (hr 66)... Top is 12z run and bottom is 0z, still a ways to go though I mean lets be real here...is that really going to sit there over baja and spin in one place for 3+ days? Seems ridiculous that it's not going to keep on movin'. Can't wait until this gets sampled. Link to comment Share on other sites More sharing options...
Lookout Posted January 25, 2014 Share Posted January 25, 2014 wpc they have icing along the mid gulf coast ...GULF COAST..A BROAD/DEEP UPPER LEVEL TROUGH WILL BE IN PLACE OVER THE EASTERN2/3 OF THE NATION WITH A COLD FRONT WELL SOUTH OF THE GULF COASTAT THE START OF THE PERIOD ALONG WITH LOW LEVEL COLD ADVECTION.THE MODEL GUIDANCE HAS BEEN ADVERTISING THE POTENTIAL FOR ASIGNIFICANT ICE STORM ALONG THE SOUTHERN GULF COAST STATES ONTUE...WITH A KEY PLAYER BEING A MID-LEVEL SHORTWAVE TROUGHDROPPING SOUTHWARD FROM THE NORTHERN ROCKIES INTO THE SOUTHERNPLAINS AND MISSISSIPPI VALLEY. THE 12Z NAM / 09Z SREF WERE THEMOST AGGRESSIVE FOR ICE ACROSS THE SOUTH...WITH A GREAT DEAL OFOVERRUNNING OF THE COLD AIR GENERATING A LARGE SWATCH OF ICE/SLEETFROM THE UPPER TEXAS COAST...ENEWD TO THE COAST OF THE CAROLINASAND SNOW ON THE NORTHERN FRINGE. GIVEN THE ENSEMBLE SPREAD AND THENAM/SREF WEIGHING IN ON THE EDGE OF THE ENSEMBLE MEMBERS WITHRESPECT TO THE UPPER TROUGH...THE WPC IDEA WAS TO DOWNPLAY THENAM/SREF IDEA BUT KEEP SOME DEGREE OF ICING INTO THE DEEPSOUTH...MORE THAN DEPICTED IN THE USUALLY TRUSTWORTHY GFS/ECMWF.GIVEN THE ENSEMBLE MEANS IN THE GEFS/EC SHOWING THE 0.10 QPF INCHLINE WELL INLAND FROM THE GULF COAST...THIS LED US TO THINK THEDETERMINISTIC GFS/EC WERE LIKELY TOO DRY. CONVERGENCE OF SOLUTIONSIS EXPECTED OVER THE NEXT 24 HOURS TOWARD SOMETHING IN THE MIDDLEOF THE EXTREMES BUT NO SINGLE DETERMINISTIC MODEL WAS FAVORED FORSNOW/ICE OUTPUT.OTTO Link to comment Share on other sites More sharing options...
Lookout Posted January 25, 2014 Share Posted January 25, 2014 wpc discussion. They stay dry inland but wanted to add their thoughts to the discussion. DAYS 2 AND 3......GULF COAST/SOUTHEAST/FL...THE MODELS ARE IN RATHER POOR CORRELATION WITH THE QPF...CERTAINLYMORE SO COMPARED TO THEIR MASS FIELD DIFFERENCES. THE MAINDIFFERENCE DEALS WITH TO WHAT DEGREE THE SRN STREAM WILL BECOMEINVOLVED IN TERMS OF BOTH THE DISTRIBUTION OF THE PCPN (I.E. HOWFAR N INTO THE GULF COAST/SOUTHEAST/SOUTHERN MID-ATLANTIC REGIONTHE PCPN WILL GET) AS WELL AS AMOUNTS...PARTICULARLY NEAR THE GULFCOAST. THE NAM TRENDED MUCH WETTER AT 12Z COMPARED TO PRIORRUNS...INDICATIVE OF A MORE PROGRESSIVE SRN STREAM WAVE AND THUS ABROADER EXPANSION OF WAA/OVERRUNNING PCPN...HOWEVER THE 18Z NAMHAS SINCE BACKED OFF ON THIS IDEA CONSIDERABLY (ESPECIALLY WITHRESPECT TO THE NRN EXTENT). HOWEVER...GIVEN THE LACK OFCONSISTENCY WITH THE NAM (AND THE SREF MEAN FOR THAT MATTER)...WPCSTAYED FAIRLY CLOSE TO A BIAS-CORRECTED GEFS MEAN...WHICH IS STILLSOMEWHAT WETTER THAN THE OPERATIONAL GFS/UKMET/ECMWF...BUTNEVERTHELESS INCORPORATES THE IDEA OF MORE SRN STREAM INTERACTIONTOWARD THE END OF DAY 3...WHICH IS WHERE THE OPERATIONAL ECMWF ISTRENDING (THOUGH AGAIN...NOT TO THE BULLISH EXTENT AS THE NAM ORSREFMEAN). EXPECT A LLVL BOUNDARY (INVERTED SFC TROUGH) TO GETFRONTOGENETIC SUPPORT VIA THE RIGHT ENTRANCE REGION OF THE UPPERLEVEL JET STREAK...ANY SRN STREAM SUPPORT WOULD ONLY AMPLIFY THEFORCING AND EXTEND THE OVERRUNNING PCPN FARTHER N INTO THE COLDERAIR. FOR FURTHER DETAILS REGARDING THE WINTER WEATHERPROBABILITIES ASSOCIATED WITH THIS SYSTEM...PLEASE REFER TO THEWPC'S SUITE OF WINTER WEATHER PRODUCTS... INCLUDING THE LATESTQPFHSD DISCUSSION. Link to comment Share on other sites More sharing options...
packbacker Posted January 25, 2014 Share Posted January 25, 2014 18z GEFS mean roughly the same as 12z GEFS mean. Just checked the 18z NAVGEM, misses the phase but close, for such a progressive model kind of what I expect. Earlier runs it had some interaction, not a lot and was producing a very nice event. Link to comment Share on other sites More sharing options...
calculus1 Posted January 25, 2014 Share Posted January 25, 2014 WPC still staying quite west with the best snow probabilities, according to the SREF mean (hat tip to WeatherNC). Here are the 1+ inch probabilities of snowfall by 00Z Wednesday. It's amazing how different these probabilities are from what all the operational models seem to be describing. As Lookout posted, those few incredibly wet members of the SREF ensemble might be overly skewing the mean left. That's one of the downsides of a mean versus a median. I wonder what the SREF median (if that were even possible to create) would look like. Link to comment Share on other sites More sharing options...
NCSU2005 Posted January 25, 2014 Share Posted January 25, 2014 WPC still staying quite west with the best snow probabilities, according to the SREF mean (hat tip to WeatherNC). Please correct me if I'm wrong, but I believe if that frame were extrapolated forward the higher probabilities would slide east some. Link to comment Share on other sites More sharing options...
downeastnc Posted January 25, 2014 Share Posted January 25, 2014 No. What WPC is probably betting on is the fact this will not be a coastal hugger meaning better snow chances further east at the coast. What that looks like is they're expecting a N/W Trend to kick in which none of the models are indicating that atm. Its either going to be no storm at all or if it there is one it will typically what happens around this area... best snow potential further west and north of the I 85 corridor. No that map is based solely on SREF output, its not made by anyone. If you read the WPC and look at their QPF outlook you would see they in fact don't think bolded at all. Link to comment Share on other sites More sharing options...
Jon Posted January 25, 2014 Share Posted January 25, 2014 Forget the baja energy for a second and focus on the northern stream energy. With that said, notice the intensity of the kicker from the 06z GFS vs the 18z GFS. Euro isn't modeling this kicker consistently, either. I know this is valid after the storm and some of you might wonder why it even matters. The reason it does is because it essentially shears out anything that wants to hang back west from the northern stream. This image compares the 06z tail end of the northern stream (red) to the 18z tail end of the northern stream (orange) Notice how it just destroys the northern stream energy. The Euro that gave central NC it's snowfall 1) Had the baja energy in a completely separate position and 2) had the kicker weaker and coming in later. If we want this to trend our way we need the baja energy to move east (obviously) but also we need the kicker not to kick us out of the play so hard. It would allow that tail end to hang and dig, and catch the baja energy if it's in the right place. Thoughts? Link to comment Share on other sites More sharing options...
DopplerWx Posted January 26, 2014 Share Posted January 26, 2014 gfs ensembles looked good for the coast, tomorrow's runs will be key with the fresh data ingested. a 100miles trend west with the precip would put the coast and far eastern carolinas in the money spot. Link to comment Share on other sites More sharing options...
NEGa Posted January 26, 2014 Share Posted January 26, 2014 the WPC maps have been odd from this morning to this evening. they were showing a widespread (albeit not heavy) snowfall. now they seem to have switched to a more widespread ice event but still not heavy (between more than .10 but less than .25) not sure what they are seeing. however, to their credit climatology might very well indicate an overrunning event with ice on top of this cold air dome Link to comment Share on other sites More sharing options...
NCSU2005 Posted January 26, 2014 Share Posted January 26, 2014 No. What WPC is probably betting on is the fact this will not be a coastal hugger meaning better snow chances further east at the coast. What that looks like is they're expecting a N/W Trend to kick in which none of the models are indicating that atm. Its either going to be no storm at all or if it there is one it will typically what happens around this area... best snow potential further west and north of the I 85 corridor. Thanks for the response...just doesn't seem to jive with the ensemble members posted on the previous page. Link to comment Share on other sites More sharing options...
pcbjr Posted January 26, 2014 Share Posted January 26, 2014 Forget the baja energy for a second and focus on the northern stream energy. With that said, notice the intensity of the kicker from the 06z GFS vs the 18z GFS. Euro isn't modeling this kicker consistently, either. I know this is valid after the storm and some of you might wonder why it even matters. The reason it does is because it essentially shears out anything that wants to hang back west from the northern stream. This image compares the 06z tail end of the northern stream (red) to the 18z tail end of the northern stream (orange) Notice how it just destroys the northern stream energy. The Euro that gave central NC it's snowfall 1) Had the baja energy in a completely separate position and 2) had the kicker weaker and coming in later. If we want this to trend our way we need the baja energy to move east (obviously) but also we need the kicker not to kick us out of the play so hard. It would allow that tail end to hang and dig, and catch the baja energy if it's in the right place. Thoughts? The only snow that ever stuck here (other than 1899) came from a low out of Baja that "meandered" along the bottom of an arctic front. I agree, Jon, we don't want that energy to get punted. Link to comment Share on other sites More sharing options...
nchighcountrywx Posted January 26, 2014 Share Posted January 26, 2014 Courtesy of Levi Cowan: His analysis could be spot on. Thinking some precip is possible around SE gulf coast & Fla, but splitting AK ridge suggests no big storm. We'll see. http://t.co/A8e1vsE94s Link to comment Share on other sites More sharing options...
beanskip Posted January 26, 2014 Share Posted January 26, 2014 Nothing like an 18z DGEX/JMA/NAM coalition to build confidence! Link to comment Share on other sites More sharing options...
calculus1 Posted January 26, 2014 Share Posted January 26, 2014 Please correct me if I'm wrong, but I believe if that frame were extrapolated forward the higher probabilities would slide east some. The SREF mean still is quite west with the bulk of the precipitation. It is one of many tools used to forecast. If this map were extrapolated further, I do not believe the high probabilities would continue to the east because that's not what the mean is currently showing. However, that doesn't mean that the SREF mean is correct. In fact, it's probably wrong and only so far west because of a few really high members. One member is currently showing 8 inches for Hickory, NC, for example. Almost all, if not all, other guidance is pointing to this "storm" hugging the coast and going out to sea. No that map is based solely on SREF output, its not made by anyone. If you read the WPC and look at their QPF outlook you would see they in fact don't think bolded at all. Yep. the WPC maps have been odd from this morning to this evening. they were showing a widespread (albeit not heavy) snowfall. now they seem to have switched to a more widespread ice event but still not heavy (between more than .10 but less than .25) not sure what they are seeing. however, to their credit climatology might very well indicate an overrunning event with ice on top of this cold air dome They are seeing a few wonky members skewing the mean really high and too far west, most likely. I bet the 21Z run will probably trend east. I hope it doesn't, but that's what all other guidance seems to suggest. At least, until we get this energy on shore and properly sampled. Anything can happen inside 48 hours, as we saw with this last little skiff of snow that gave a good portion of NC a little dusting. All this to say, this storm is not written in stone, one way or the other, yet. I'm not a panicky cliff-diver, yet I'm quite realistic too. Things do not look too positive for areas west of I-95, much less west of I-77, right now. That could change by Monday or it could not. I'll just sit back and watch. Whatever will be, will be. Link to comment Share on other sites More sharing options...
packfan98 Posted January 26, 2014 Share Posted January 26, 2014 21z sref's are correcting East. Remember that they are Short Range models and we are not quite into the short range yet. They might be more useful with less than 48 hours before a storm. Link to comment Share on other sites More sharing options...
NEGa Posted January 26, 2014 Share Posted January 26, 2014 The SREF mean still is quite west with the bulk of the precipitation. It is one of many tools used to forecast. If this map were extrapolated further, I do not believe the high probabilities would continue to the east because that's not what the mean is currently showing. However, that doesn't mean that the SREF mean is correct. In fact, it's probably wrong and only so far west because of a few really high members. One member is currently showing 8 inches for Hickory, NC, for example. Almost all, if not all, other guidance is pointing to this "storm" hugging the coast and going out to sea. They are seeing a few wonky members skewing the mean really high and too far west, most likely. I bet the 21Z run will probably trend east. I hope it doesn't, but that's what all other guidance seems to suggest. At least, until we get this energy on shore and properly sampled. Anything can happen inside 48 hours, as we saw with this last little skiff of snow that gave a good portion of NC a little dusting. i tend to agree sadly on the no west shift unfortunately. ironic all this cold air and finally maybe a good storm and the cold air shunts it away from most of us lol it would seem like if the storm is more to the east then there would be less chance of any ice in the interior, not more as they seem to be showing (unless i am just reading it wrong) Link to comment Share on other sites More sharing options...
jtomlinwx Posted January 26, 2014 Share Posted January 26, 2014 I'm relatively new to the in-depth model analyzing. Would someone be kind enough to explain to me what is meant by the "fresh data" the models will receive tomorrow? Thanks! Link to comment Share on other sites More sharing options...
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