rduwx Posted February 16, 2012 Share Posted February 16, 2012 18Z is not exciting at all. Same land track, then out to sea with the NAO the way it is. Winners are mtn locations Agree that the 18z gfs is not all that exciting. Maybe it'll end as some snow but the main thing that we're looking at today is trends. The trend of the day is slower and further south. If (big if) that trend continues then we could be talking about something here. Link to comment Share on other sites More sharing options...
packbacker Posted February 16, 2012 Share Posted February 16, 2012 GFS Ens is about 3 hours slower and a tad SE of the OP, SLP tracks right over NC/SC border and heads NE from there. Nice track, shift it about 50 miles south and we could be in business, I have feeling that we are seeing the southward extent of this event. Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 16, 2012 Share Posted February 16, 2012 Anyone read the HPC disco? http://www.daculaweather.com/hpc_disco.php THE 06Z GFS/00Z ECMWF HAVE CONVERGED ON A SOLUTION NEARBY THE NC/SC BORDER WHICH ALSO COMPARES FAVORABLY WITH THE 00Z GEFS/ECMWF ENS/NAEFS MEAN. Link to comment Share on other sites More sharing options...
WeatherNC Posted February 16, 2012 Share Posted February 16, 2012 GFS Ens is about 3 hours slower and a tad SE of the OP, SLP tracks right over NC/SC border and heads NE from there. Nice track, shift it about 50 miles south and we could be in business, I have feeling that we are seeing the southward extent of this event. Agree, wanted to post the 60hr graphic vs the 6z mean at 72, take a look at RAH's site for comparison as that is more telling imo, but will post the 72hr vs 6z @ 84, slower, with maybe some evidence of members trending more favorable for at-least the NW part of our state... Sig difference, that hp over lakes, several 12z members (maybe even a majority) were stronger than the op, running avg 1027 range, not a great source of could but considering yesterday we were still contending with a disturbance in that area, good shift. 6z @ 84 18z @ 72 Link to comment Share on other sites More sharing options...
Isopycnic Posted February 16, 2012 Share Posted February 16, 2012 DT "Guesses" http://www.wxrisk.com/wp-content/uploads/2012/02/1STGUESS.jpg Link to comment Share on other sites More sharing options...
SeVa Posted February 16, 2012 Share Posted February 16, 2012 I am liking the trends for Hampton Roads. It won't take too many changes for us to eek out a quick 1-2inches in the evening. Link to comment Share on other sites More sharing options...
WeatherNC Posted February 16, 2012 Share Posted February 16, 2012 Anyone read the HPC disco? http://www.daculawea...m/hpc_disco.php THE 06Z GFS/00Z ECMWF HAVE CONVERGED ON A SOLUTION NEARBY THE NC/SC BORDER WHICH ALSO COMPARES FAVORABLY WITH THE 00Z GEFS/ECMWF ENS/NAEFS MEAN. EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 215 PM EST THU FEB 16 2012 VALID 12Z SUN FEB 19 2012 - 12Z THU FEB 23 2012 ...UPDATES FROM THE 12Z GUIDANCE... WITH REGARD TO THE POTENTIAL WINTER STORM ACROSS THE MID-ATLANTIC...THERE WAS A TREND NOTED WITH THE ARRIVAL OF THE SUITE OF 12Z GUIDANCE. THE MOST PRONOUNCED SHIFT WAS SEEN IN THE 12Z ECMWF WHICH SEEMED TO BACK UP THE CYCLONE A GOOD 6 HR IN PROGRESSION COMPARED TO THE 00Z ECMWF RUN. THIS PLACES IT CLOSER TO WHERE THE 12Z/00Z UKMET...BUT STILL NOT AS FAR SOUTH AND WEST AS THE 12Z CMC WHICH MAINTAINED ITS POSITION FROM EARLIER. THE 12Z GFS NOW RESIDES ON THE EASTERN FRINGE OF THE MODEL SPREAD WITH A SOLUTION THAT LOOKS VERY MUCH LIKE THAT OF ITS PRECEDING RUN AS WELL AS THE 12Z/06Z GEFS MEAN. TO ACCOUNT FOR THE TRENDS IN THE 12Z MODELS...THE FRONTAL SYSTEM WAS SLOWED A TAD WHICH PLACES IT CLOSER TO THAT OF THE 12Z GFS. THE OTHER MAJOR PLAYER IS THE AMPLIFIED UPPER TROF ACROSS THE WEST. WITH THE EXCEPTION OF THE 12Z UKMET/ECMWF...THERE STILL REMAINS SUPPORT FOR THE PREFERRED SLOWER SOLUTION OF THE EJECTING LONGWAVE TROF ACROSS NORTHERN MEXICO. ONE POSITIVE SIGN WAS THE 12Z ECMWF BACKED OFF ON THE SIGNIFICANT TROF OVER THE MID-ATLANTIC ON DAY 6 WITH THE SYSTEM NOW DISPLACED WELL TO THE NORTH. MODEL DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 219 PM EST THU FEB 16 2012 VALID FEB 16/1200 UTC THRU FEB 20/0000 UTC ...SEE NOUS42 KWNO ADMNFD FOR THE STATUS OF THE UPPER AIR INGEST... 12Z NAM/GFS EVALUATION INCLUDING THE ECMWF AND PREFERENCES ...SHORTWAVE TROUGH OVER THE OHIO VALLEY... LARGE-SCALE MODEL FORECASTS ARE SIMILAR. ...UPPER LOW NEAR SOUTHERN CALIFORNIA... PREFERENCE: GFS OR 00Z ECMWF THE SOLUTION SPREAD IS QUITE SUBSTANTIAL FROM SATURDAY ONWARD...WITH THE LOW'S TRACK POSSIBLY DEPENDENT UPON THE EVOLUTION AND INTERACTIONS OF 3 SEPARATE SHORTWAVE TROUGHS MOVING TO ITS NORTH. MODEL INITIALIZATION OF THESE SYSTEMS IS A CONCERN...PARTICULARLY THE SHORTWAVE TROUGH ENTERING BRITISH COLUMBIA...WITH MID-LEVEL DIAGNOSTICS FIELDS FROM THE GFS ALIGNING BEST WITH THE STRUCTURE SEEN ON WATER VAPOR IMAGERY COMPARED TO THE NAM AND ECMWF...WHICH APPEAR WORST. AMONG THE REMAINING SOLUTIONS...THE CANADIAN PRODUCES AN OUTLIER SOLUTION CROSSING THE GULF COAST AND THUS IS DISCARDED...WHILE THE UKMET IS VERY MUCH LIKE THE NAM/ECMWF BUT HAS A TENDENCY TO OVER-DEVELOP OR DEEPEN CYCLONES. THUS...CONFIDENCE IN THE UKMET IS LOW. FINALLY...THE GLOBAL ENSEMBLE MEANS...INCLUDING THE GFS/ECMWF ENSEMBLE MEANS ARE SLIGHTLY SLOWER AND FASTER THAN THE GFS RESPECTIVELY BUT WHEN AVERAGED RESULT IN A GFS-LIKE SOLUTION. THUS...ENSEMBLE MEMBER SUPPORT FOR THE GFS IS QUITE GOOD...AND GIVEN THE EXISTING SPREAD AND UNCERTAINTY INVOLVING MULTIPLE SMALL-SCALE SYSTEMS...THE ENSEMBLE MEANS MAY OFFER THE MOST MEANINGFUL AND CONSISTENT DAY-TO-DAY FORECAST CHANGES THAT ADEQUATELY ACCOUNT FOR THE POTENTIAL SOLUTION ENVELOPE. ANOTHER ALTERNATIVE WOULD BE TO USE A POOR-MANS ENSEMBLE THAT AVERAGES ALL OF THE DETERMINISTIC SOLUTIONS...EXCEPT FOR PERHAPS THE CANADIAN WHICH IS AN OUTLIER. HOWEVER...THIS APPROACH MAY NOT PROPERLY ACCOUNT FOR THE DISPERSION OF SOLUTIONS. THUS...UNTIL THESE MULTIPLE SYSTEMS CAN BE BETTER SAMPLED...THE PREFERENCE IS BETWEEN THE GFS/ECMWF ENSEMBLE MEANS...WHICH IS BEST APPROXIMATED BY THE 12Z OPERATIONAL GFS WITH THE 00Z ECMWF A CLOSE SECOND. CONFIDENCE: LOW ...SHORTWAVE TROUGH INFLUENCING THE PLAINS/MIDWEST/GREAT LAKES FRI-SAT... PREFERENCE: GFS OR 00Z ECMWF THE GFS LIES NEAR THE MODEL CONSENSUS...WHILE THE NAM/ECMWF ARE FASTER. GIVEN LARGER-SCALE PREFERENCES AND INITIALIZATION CONCERNS DESCRIBED ABOVE...FOR CONSISTENCY THE PREFERENCE IS FOR THE GFS OR THE 00Z ECMWF. CONFIDENCE: LOW http://www.hpc.ncep.noaa.gov/html/discuss.shtml Link to comment Share on other sites More sharing options...
CAD_Wedge_NC Posted February 16, 2012 Share Posted February 16, 2012 Agree, wanted to post the 60hr graphic vs the 6z mean at 72, take a look at RAH's site for comparison as that is more telling imo, but will post the 72hr vs 6z @ 84, slower, with maybe some evidence of members trending more favorable for at-least the NW part of our state... Sig difference, that hp over lakes, several 12z members (maybe even a majority) were stronger than the op, running avg 1027 range, not a great source of could but considering yesterday we were still contending with a disturbance in that area, good shift. I agree with the idea that this set-up is trending away from the full phasing we saw in earlier runs. To my untrained eye, if you look at the GFS 12z runs vs. the 18z runs you can see the timing is becoming less favorable for a big phase. This might get interesting after all........ Overall, I like the slower solutions we are seeing from the latest runs. As mentioned before, it will give time for the HP to build in and the 50/50 to become better established. If tonight's solutions continue with the trend of slowing the system down and digging it further southward, coupled with more confluence over SE Canada, then we could all get into some fun and games. Still a lot of time before we see the exact outcome of this winter storm, but it has lots of potential. Link to comment Share on other sites More sharing options...
Jon Posted February 17, 2012 Share Posted February 17, 2012 DT "Guesses" http://www.wxrisk.co...02/1STGUESS.jpg I'll be well inside the 8"+ area this Sunday. Bad news is the gf doesn't want to be stranded in SE WV so she'll want to leave before any real snow falls. Link to comment Share on other sites More sharing options...
HKY_WX Posted February 17, 2012 Share Posted February 17, 2012 Something I noticed when looking over the latest UKMET/GFS. These two models tend to shift in trends and they are both trending each run towards separating the wave in the northern stream that previously was coming in and speeding up/taking over the southern s/w. What this is doing, is reducing the shear on the southern vort and preventing it from speeding up. This also is allowing the sfc HP time to slide in, deflecting the SLP from tracking towards the NE into the Apps or Piedmont of the southeast. In the latter frames of the animation below, you can see how the piece which jet's east over the great lakes allows the sfc HP to slide in relatively fast and also allows the other northern stream s/w piece to slide in behind the incoming stj vort and creating the deformation/upper low zone on the back side. Ultimately I think this is the models starting to realizing the strength of the southern branch. It is essentially forcing the polar jet energy to split into two different pieces instead of shearing apart the southern stream and sending it northeast into the Tennessee Valley. You can see how massive it is below on the WV loop. Something to watch tonight for trending purposes. Link to comment Share on other sites More sharing options...
Rankin5150 Posted February 17, 2012 Share Posted February 17, 2012 Something I noticed when looking over the latest UKMET/GFS. These two models tend to shift in trends and they are both trending each run towards separating the wave in the northern stream that previously was coming in and speeding up/taking over the southern s/w. What this is doing, is reducing the shear on the southern vort and preventing it from speeding up. This also is allowing the sfc HP time to slide in, deflecting the SLP from tracking towards the NE into the Apps or Piedmont of the southeast. In the latter frames of the animation below, you can see how the piece which jet's east over the great lakes allows the sfc HP to slide in relatively fast and also allows the other northern stream s/w piece to slide in behind the incoming stj vort and creating the deformation/upper low zone on the back side. Ultimately I think this is the models starting to realizing the strength of the southern branch. It is essentially forcing the polar jet energy to split into two different pieces instead of shearing apart the southern stream and sending it northeast into the Tennessee Valley. You can see how massive it is below on the WV loop. Something to watch tonight for trending purposes. AWESOME write-up Brandon! Great points to consider. Hope all is well!! Link to comment Share on other sites More sharing options...
jburns Posted February 17, 2012 Share Posted February 17, 2012 I'll be well inside the 8"+ area this Sunday. Bad news is the gf doesn't want to be stranded in SE WV so she'll want to leave before any real snow falls. For God sakes man, lie to her. This is a one storm year. Link to comment Share on other sites More sharing options...
superjames1992 Posted February 17, 2012 Share Posted February 17, 2012 I'll be well inside the 8"+ area this Sunday. Bad news is the gf doesn't want to be stranded in SE WV so she'll want to leave before any real snow falls. You have to make it happen. Have to stay! Where are going going in SE WV? I think you need to take the gf up to Flat Top Mountain to go skiing at Winterplace. The skiing would be awesome with the snow falling and you've got ~3,500 ft. elevation at Flat Top. Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 FWIW SREF Mean @15z has snow for a good chunk of NC...from just north of CLT @84 to just west of RDU @84 then most of NC as it's exiting @87. Eastern NC is mostly all rain. Link to comment Share on other sites More sharing options...
WeatherNC Posted February 17, 2012 Share Posted February 17, 2012 18z GFS mems best vs worst Best Worst 18z overall, most give the boarder counties at-least an advisory level event, several with some tokens down into the triangle 12z for comparison, funny how p004 went from 1'+ for NW VA to our worst case with 18z Link to comment Share on other sites More sharing options...
valkhorn Posted February 17, 2012 Share Posted February 17, 2012 18z GFS mems best vs worst Best Worst 18z overall, most give the boarder counties at-least an advisory level event, several with some tokens down into the triangle 12z for comparison, funny how p004 went from 1'+ for NW VA to our worst case with 18z And Knoxville gets shafted This is going to be tempting to drive to somewhere along I81 to see this in action. Link to comment Share on other sites More sharing options...
DaculaWeather Posted February 17, 2012 Share Posted February 17, 2012 Here's the HPC Snow and Ice Disco. They mentioned things slowing down some too. http://www.daculaweather.com/hpc_prob_snow_disco.php Link to comment Share on other sites More sharing options...
tnweathernut Posted February 17, 2012 Share Posted February 17, 2012 Looking like the 0z NAM is a little sharper with the southern vort at 36 with a 2 mb better high in the midwest (1028 vs 1026) Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 NAM is out to 36...this keeps our energy out west slow...lines up with 18z NAM. It does look different at 500..energy over the Lakes is sharper. Some light energy diving down the Rockies and not as much separation in the streams. Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 @42 it looks interesting....though it may phase with that energy near the plains? Link to comment Share on other sites More sharing options...
packbacker Posted February 17, 2012 Share Posted February 17, 2012 Interesting the northern stream is a little quicker. Link to comment Share on other sites More sharing options...
tnweathernut Posted February 17, 2012 Share Posted February 17, 2012 NAM has a lot of interaction between the streams at 42. I would think this plasters eastern KY and western VA and West Virginia Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 One bad thing, NAM looks further north and looks close to 18z GFS at the same time frame out to 48. This is what Chris talked about earlier why you should throw out the 12z and 18z runs it didn't have that energy in the plains. Link to comment Share on other sites More sharing options...
Dunkman Posted February 17, 2012 Share Posted February 17, 2012 One bad thing, NAM looks further north and looks close to 18z at the same time frame. It's not farther north at 48h...not yet at least. It is slower, and stronger. 0z 48h 18z 54h Link to comment Share on other sites More sharing options...
tnweathernut Posted February 17, 2012 Share Posted February 17, 2012 It's a little faster than the 18z NAM, but the low is also a little stronger (probably a reason it's a little further north, looks like a negative tilt a little sooner than 18z) the high pressure to the north is also a little stronger.....by a smidge. Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 It is slower than the 18z GFS @51 and not as much interaction...I've got too many windows open on this laptop Link to comment Share on other sites More sharing options...
tnweathernut Posted February 17, 2012 Share Posted February 17, 2012 It's not farther north at 48h...not yet at least. It is further north, or a little faster when you compare the 54 hr 18z NAM with the 48 0z. Edit: Maybe I need to clear my cache, lol. Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 It is further north, or a little faster when you compare the 54 hr 18z NAM with the 48 0z. Edit: Maybe I need to clear my cache, lol. Looks like TN might get hammered in the next few frames. Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 @60 it still hasn't really phased. Link to comment Share on other sites More sharing options...
tnweathernut Posted February 17, 2012 Share Posted February 17, 2012 Looks like TN might get hammered in the next few frames. I can see Kentucky getting hammered, not so sure about TN. Low is further north and going more severely negative sooner which should lift that low further north than previous runs. JMO Link to comment Share on other sites More sharing options...
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