tmagan Posted January 6, 2011 Share Posted January 6, 2011 p type issues? or coastal hugger with enough blocking making it all snow up until you get to the actual low? No blocking high to the north always means you can have p-type problems, but with this high amplitude pattern, I'd be surprised if this didn't head up the coast. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 I actually agree with this as well...i actually just wrote a whole discussion on it.... I want this storm to have the track depicted in your sig and avatar Nice amplification btw lol Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 On another note its damn cold this morning-- getting close to the teens here! Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 6, 2011 Share Posted January 6, 2011 On another note its damn cold this morning-- getting close to the teens here! Its actually 18 currently here ..I walked to the store a little while ago and needed two jackets Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 6, 2011 Share Posted January 6, 2011 6Z GFS still holds on to a coastal. Not really even a phase with the southern wave but more of a kickout of the leftover mid level circulation. Link to comment Share on other sites More sharing options...
ptb127 Posted January 6, 2011 Share Posted January 6, 2011 I hope you guys are right about the coastal hugger idea.. Seems like this has a better chance to track further west then the last storm did. As modeled right now it's a miss for areas that missed the blizzard earlier in Dec and the friday storm..... Link to comment Share on other sites More sharing options...
TheTrials Posted January 6, 2011 Share Posted January 6, 2011 A very interesting HPC disco, here is the day 5 part and a link to the full text. Interesting about the sampling and the models handling this system better. Could be why we see such similar solutions last night other than the Euro. GUIDANCE DIVERGES FROM DAY 5 TUE ONWARD. DUE TO THE 00Z ECMWF TRENDING SLOWER THAN CONSENSUS WITH ENERGY CROSSING THE CONUS DURING THE PERIOD... THAT MODEL EJECTS THE INITIAL WAVE EWD INTO THE ATLC AND THEN TAKES ANOTHER 1-2 DAYS TO DEVELOP ITS STRONGER WRN ATLC SFC LOW THAT ENDS UP ON THE SRN FRINGE OF THE MODEL/ENSEMBLE ENVELOPE. 00Z GEFS/12Z ECMWF ENSEMBLES SHOW BEST CLUSTERING A LITTLE EWD OF THE 00Z GFS BUT THE GFS IS WITHIN THE SOLN ENVELOPE AND THE UKMET/CMC TRACKS ALSO FALL IN THE MIDDLE TO WRN HALF OF THE SPREAD. WITH ENSEMBLE MEANS OFFERING THE BEST CONTINUITY AMONG GUIDANCE SO FAR... PREFER TO LEAN MORE TOWARD THE 00Z GEFS/12Z ECMWF MEANS WITH ABOUT 1/3 WEIGHTING OF THE GFS TO PROVIDE SOME ADDED STRENGTH FROM DAY 5 TUE ONWARD. IT IS HOPED THAT WITH A LARGER PROPORTION OF THE SUPPORTING ENERGY CROSSING A MAJORITY OF THE CONUS VERSUS ENTERING THE CONUS FROM CANADA WHERE MDLS HAVE MORE DIFFICULTY RESOLVING SHRTWV FEATURES... THAT THIS SYSTEM WILL ULTIMATELY HAVE SOMEWHAT BETTER PREDICTABILITY THAN PRECEDING SYSTEMS AFFECTING THE EAST COAST. http://www.hpc.ncep.noaa.gov/preepd/preepd.html Link to comment Share on other sites More sharing options...
Ji Posted January 6, 2011 Share Posted January 6, 2011 6Z GFS still holds on to a coastal. Not really even a phase with the southern wave but more of a kickout of the leftover mid level circulation. thats even a better sign right? that it could produce a similar storm without a phase Link to comment Share on other sites More sharing options...
am19psu Posted January 6, 2011 Author Share Posted January 6, 2011 It's not really a phase, at least in the typical sense. If you look at the vorticity maps on the eWall, you'll see the southern s/w gets sheared out, but the western s/w arrives in time to keep cyclongenesis going. Lee Grenci would call that a "one-two punch" instead of a phase. Euro ensemble members are all over the board again. 10% show a Miller B, probably 40% show some sort of coastal event, and 50% are OTS. Ish. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 It's not really a phase, at least in the typical sense. If you look at the vorticity maps on the eWall, you'll see the southern s/w gets sheared out, but the western s/w arrives in time to keep cyclongenesis going. Lee Grenci would call that a "one-two punch" instead of a phase. Euro ensemble members are all over the board again. 10% show a Miller B, probably 40% show some sort of coastal event, and 50% are OTS. Ish. That Ish part at the end is the best lol I had a vision of a system going out to sea and then hooking back at the last moment, leaving you in suspense lol. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 6, 2011 Share Posted January 6, 2011 thats even a better sign right? that it could produce a similar storm without a phase I don't even know what to call it. All guidance is now suggesting the southern wave drops right along the GOM and/or into the GOM. There are a lot of complex interaction going on here. One thing is pretty certain. There will be a LOT of precipitation/convection with this system, and when dealing with migratory lows like this, a ton of diabatic heat is released through the depth of the wave when they interact with the GOM under this scenario. Heights rise quickly as a result of the latent warming and the system craps out fast. GFS suggests this. ECM on the other hand keeps the wave in the mid levels in-tact, and as a response to the incoming trough, the height field response is to "kick" the migratory low out ahead of the east progressing trough. As Am19psu said, the GFS has the migratory wave crapping out real fast as heights rise rapidly. The western trough moves in as this process occurs and helps support continued low level cyclogenesis as the system heads E. CMC is junk and I don't even consider it a valid solution in the way it handles the migrating southern wave even though it eventually develops a similar solution to the GFS. As you can see though, the GFS is real close to losing this storm OTS. If the incoming trough is too slow, low level cyclogenesis weakens too much and there will be weak development and an OTS solution. Link to comment Share on other sites More sharing options...
Jet-Phase Posted January 6, 2011 Share Posted January 6, 2011 A very interesting HPC disco, here is the day 5 part and a link to the full text. Interesting about the sampling and the models handling this system better. Could be why we see such similar solutions last night other than the Euro. GUIDANCE DIVERGES FROM DAY 5 TUE ONWARD. DUE TO THE 00Z ECMWF TRENDING SLOWER THAN CONSENSUS WITH ENERGY CROSSING THE CONUS DURING THE PERIOD... THAT MODEL EJECTS THE INITIAL WAVE EWD INTO THE ATLC AND THEN TAKES ANOTHER 1-2 DAYS TO DEVELOP ITS STRONGER WRN ATLC SFC LOW THAT ENDS UP ON THE SRN FRINGE OF THE MODEL/ENSEMBLE ENVELOPE. 00Z GEFS/12Z ECMWF ENSEMBLES SHOW BEST CLUSTERING A LITTLE EWD OF THE 00Z GFS BUT THE GFS IS WITHIN THE SOLN ENVELOPE AND THE UKMET/CMC TRACKS ALSO FALL IN THE MIDDLE TO WRN HALF OF THE SPREAD. WITH ENSEMBLE MEANS OFFERING THE BEST CONTINUITY AMONG GUIDANCE SO FAR... PREFER TO LEAN MORE TOWARD THE 00Z GEFS/12Z ECMWF MEANS WITH ABOUT 1/3 WEIGHTING OF THE GFS TO PROVIDE SOME ADDED STRENGTH FROM DAY 5 TUE ONWARD. IT IS HOPED THAT WITH A LARGER PROPORTION OF THE SUPPORTING ENERGY CROSSING A MAJORITY OF THE CONUS VERSUS ENTERING THE CONUS FROM CANADA WHERE MDLS HAVE MORE DIFFICULTY RESOLVING SHRTWV FEATURES... THAT THIS SYSTEM WILL ULTIMATELY HAVE SOMEWHAT BETTER PREDICTABILITY THAN PRECEDING SYSTEMS AFFECTING THE EAST COAST. http://www.hpc.ncep....epd/preepd.html A question for the Mets out there: Does the NOGAPS ever get figured into the HPC discussion at all? If it's as bad as I am to believe here based on comments that I see, what is the model used for? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 6, 2011 Share Posted January 6, 2011 A question for the Mets out there: Does the NOGAPS ever get figured into the HPC discussion at all? If it's as bad as I am to believe here based on comments that I see, what is the model used for? I don't read the discos, but I doubt it. NOGAPS isn't part of the NCEP suite, and in all honesty it is a rather archaic model compared to the rest of the global guidance. The verification scores reflect that. The NAVY runs it, and if anything, I think mostly to initialize some of their other simulations. Link to comment Share on other sites More sharing options...
am19psu Posted January 6, 2011 Author Share Posted January 6, 2011 The GFS ops is the 3rd most amplified member of the ensemble guidance. Most of the members are OTS at 6z. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 The GFS ops is the 3rd most amplified member of the ensemble guidance. Most of the members are OTS at 6z. is the ensemble mean very OTS or just a bit east of the OP? From the HPC discussion above it seemed like they thought it was just a tick east of the OP, although its hard to tell with their wording. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 I don't read the discos, but I doubt it. NOGAPS isn't part of the NCEP suite, and in all honesty it is a rather archaic model compared to the rest of the global guidance. The verification scores reflect that. The NAVY runs it, and if anything, I think mostly to initialize some of their other simulations. Has their ever been a move to "fix" these old models to make them run better, or have they just basically been replaced and are only run for legacy reasons? Link to comment Share on other sites More sharing options...
am19psu Posted January 6, 2011 Author Share Posted January 6, 2011 is the ensemble mean very OTS or just a bit east of the OP? From the HPC discussion above it seemed like they thought it was just a tick east of the OP, although its hard to tell with their wording. At 138, the GFS ops has the surface low at 39N 72.5W, while the mean has it at 39N 70W. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 6, 2011 Share Posted January 6, 2011 Has their ever been a move to "fix" these old models to make them run better, or have they just basically been replaced and are only run for legacy reasons? I am not an expert on NOGAPS or FNMOC by any stretch of the imagination, but it always comes down to money. Running a global model takes a lot of testing and work to make it reliable/accurate. Moreover, it takes quite a bit of computing horsepower to "modernize" models to take advantage of things such as more advanced data assimilation schemes (4dvar, ensemble Kalman filtering, etc.) and higher resolutions (both vertical and horizontal). FNMOC does run other simulations including oceanographic simulations, so perhaps it is mostly run to initialize those products. Definitely not run for legacy purposes since it would be a huge waste of computing power--my feeling is it is used for initialization purposes. Anyone with more knowledge/expertise feel free to chime in and/or correct me. Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 6, 2011 Share Posted January 6, 2011 Obviously not the same time frame because they are 12 hours apart but the 06 Z means is SW of the 00z Means..referring to the GFS... 6Z http://raleighwx.americanwx.com/models/gfsensemble/06zgfsensemblep12132.gif versus 00z http://raleighwx.americanwx.com/models/gfsensemble/00zgfsensemblep12144.gif 6 Z http://raleighwx.americanwx.com/models/gfsensemble/06zgfsensemblep12144.gif Versus 00z http://raleighwx.americanwx.com/models/gfsensemble/00zgfsensemblep12156.gif And if you just want to use 144 hrs 6 z http://raleighwx.americanwx.com/models/gfsensemble/06zgfsensemblep12144.gif versus 0z http://raleighwx.americanwx.com/models/gfsensemble/00zgfsensemblep12144.gif Even in that case the precipitation on 6 is further to the NW.... Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 I am not an expert on NOGAPS or FNMOC by any stretch of the imagination, but it always comes down to money. Running a global model takes a lot of testing and work to make it reliable/accurate. Moreover, it takes quite a bit of computing horsepower to "modernize" models to take advantage of things such as more advanced data assimilation schemes (4dvar, ensemble Kalman filtering, etc.) and higher resolutions (both vertical and horizontal). FNMOC does run other simulations including oceanographic simulations, so perhaps it is mostly run to initialize those products. Definitely not run for legacy purposes since it would be a huge waste of computing power--my feeling is it is used for initialization purposes. Anyone with more knowledge/expertise feel free to chime in and/or correct me. Yea legacy was a poor choice of words on my part lol-- I was really trying to say do they use it to "boot up" their more refined products? Even with its errors, I like looking at old NOGAPS and ETA output sometimes, just to hear a different voice, so to speak. Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 6, 2011 Share Posted January 6, 2011 OP 6 z at 144 http://raleighwx.americanwx.com/models/gfs/06zgfs850mbTSLPp06144.gif Versus Means 144 http://raleighwx.americanwx.com/models/gfsensemble/06zgfsensemblep12144.gif Yes the OP is West of the means but pretty much that is always the case at this range... Despite that everything on the 6Z means versus 00z means looks improved..... Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 6, 2011 Share Posted January 6, 2011 Also that most progressive model with a SE known Bias is further west once again .... And that is the one thing that this model is good for ..... Usually this model would be well south and east but its actually even more west... HM mentioned a few days ago about this having the potential to cut and be really amped up... 2. The Jan 11-12 storm has plenty of room to amplify; and while there is a 50-50 low feature, it seems to be moving out to allow this thing to amplify solidly. Also the mean confluence behind the departing 50-50 low weakens with no major CAD signature. This storm, if it wants to, could amplify to the point where a lot of people in the coastal plain change over. Watch for the inevitable H8-7 warming with a setup like this that brings the joyful sounds of sleet to many snow enthusiasts. That being said, there is certainly potential for this to be a solid winter storm for many. and that is exactly what this model is showing.... Link to comment Share on other sites More sharing options...
ChescoWx Posted January 6, 2011 Share Posted January 6, 2011 Early look at the Wxsim module detail for the NW Philly burbs has snow developing early in the morning on Tuesday becoming heavy during the day with around 8" of snow accumulating by day's end Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 6, 2011 Share Posted January 6, 2011 Yea legacy was a poor choice of words on my part lol-- I was really trying to say do they use it to "boot up" their more refined products? Even with its errors, I like looking at old NOGAPS and ETA output sometimes, just to hear a different voice, so to speak. If anything, I think this is likely its main use. In all honesty it is completely inferior to the GFS/ECM and even the UK/CMC. I just don't see any use in using it as a forecast utility. Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 6, 2011 Share Posted January 6, 2011 If anything, I think this is likely its main use. In all honesty it is completely inferior to the GFS/ECM and even the UK/CMC. I just don't see any use in using it as a forecast utility. Not at all saying its a good model by any stretch of the imagination but at day 6 (Northern Hem) it is just slightly underneath the ECM (which has dipped low in verification) NH Day 6 Verification About the only good this model has is flagging when the others are too far to the east....when its showing alot further west because of its notorious SE bias with coastals Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 6, 2011 Share Posted January 6, 2011 Not at all saying its a good model by any stretch of the imagination but at day 6 (Northern Hem) it is just slightly underneath the ECM (which has dipped low in verification) NH Day 6 Verification About the only good this model has is flagging when the others are too far to the east....when its showing alot further west because of its notorious SE bias with coastals One of the models is now showing a track right over NYC which would probably put the rain/snow line in upstate NY.... not liking this trend at all. Granted its the DGEX but still. Link to comment Share on other sites More sharing options...
TheTrials Posted January 6, 2011 Share Posted January 6, 2011 Also that most progressive model with a SE known Bias is further west once again .... And that is the one thing that this model is good for ..... Usually this model would be well south and east but its actually even more west... HM mentioned a few days ago about this having the potential to cut and be really amped up... and that is exactly what this model is showing.... I have seen the NOGAPS have a few moments but two days ago it was showing a 960 something bomb on the benchmark for the Norlun event tomorrow, so take that fwiw. Link to comment Share on other sites More sharing options...
am19psu Posted January 6, 2011 Author Share Posted January 6, 2011 Here are the 6z GFS ensemble member tracks (0z didn't come in for some reason) - note no Miller Bs here: And the 0z CMC ensemble members - only about 7/20 Miller Bs: I think I can put the Miller B idea to bed. Now it's really trying to figure out if it is going to come up the coast or head OTS. Link to comment Share on other sites More sharing options...
showmethesnow Posted January 6, 2011 Share Posted January 6, 2011 Here are the 6z GFS ensemble member tracks (0z didn't come in for some reason) - note no Miller Bs here: And the 0z CMC ensemble members - only about 7/20 Miller Bs: I think I can put the Miller B idea to bed. Now it's really trying to figure out if it is going to come up the coast or head OTS. I have always wondered when you look at these charts and they have different groupings are you able to determine if there is a common denominator for each group so that you have an idea on what to key on as far as an outcome? Link to comment Share on other sites More sharing options...
Rainshadow Posted January 6, 2011 Share Posted January 6, 2011 A question for the Mets out there: Does the NOGAPS ever get figured into the HPC discussion at all? If it's as bad as I am to believe here based on comments that I see, what is the model used for? Not often. Neither does the dgex. Both are accessible. Nogaps ensemble members are planned to be included in the NAEFS ensemble system I believe sometime later this month. Link to comment Share on other sites More sharing options...
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