OKpowdah Posted October 31, 2012 Share Posted October 31, 2012 Long range model guidance is suggesting that the pattern over the Pacific becomes more progressive by next week. This in part supported by positive torque anomalies in the subtropics. The GWO is entering phase 4 and 5 and about to swing into a significant positive phase. The +AAM anomalies propagate poleward, supporting a more progressive pattern in the mid latitudes. Anyway, as this occurs, shortening wavelengths will kick the persistent trough over Alaska southeast toward the Pacific NW by the middle of next week. GEFS show this fall in the PNA ... while also a huge spike in the AO (as supported by the AAM propagation). So it looks like by the end of next week into next weekend, we'll be watching an increasingly active pattern in the Plains. Link to comment Share on other sites More sharing options...
CoastalWx Posted October 31, 2012 Share Posted October 31, 2012 Long range model guidance is suggesting that the pattern over the Pacific becomes more progressive by next week. This in part supported by positive torque anomalies in the subtropics. The GWO is entering phase 4 and 5 and about to swing into a significant positive phase. The +AAM anomalies propagate poleward, supporting a more progressive pattern in the mid latitudes. Anyway, as this occurs, shortening wavelengths will kick the persistent trough over Alaska southeast toward the Pacific NW by the middle of next week. GEFS show this fall in the PNA ... while also a huge spike in the AO (as supported by the AAM propagation). So it looks like by the end of next week into next weekend, we'll be watching an increasingly active pattern in the Plains. What are your thoughts of increasing mtn torque perhaps making things blockier again? Also, ins't increased AAM a precursor to this? Link to comment Share on other sites More sharing options...
brettjrob Posted October 31, 2012 Share Posted October 31, 2012 Link to comment Share on other sites More sharing options...
mnweather Posted October 31, 2012 Share Posted October 31, 2012 Euro looks like it has a day 10 system. Looking warm ahead of it. Link to comment Share on other sites More sharing options...
andyhb Posted October 31, 2012 Share Posted October 31, 2012 GFS has had this for at least 4 runs in a row now. In addition to essentially all of the ensembles. Link to comment Share on other sites More sharing options...
OKpowdah Posted October 31, 2012 Author Share Posted October 31, 2012 What are your thoughts of increasing mtn torque perhaps making things blockier again? Also, ins't increased AAM a precursor to this? The increase in AAM occurring now seems to be mostly located in the subtropics, and is probably related to the coinciding increase in blocking. I think in the next 10 days we'll see the MT AAM anomalies propagated poleward, combined with the FT anomalies around 60N = a big increase in the AO, which we see in the GEFS. This also coincides with the MJO weakening, and cycling across the Indian Ocean. So I think at the very least, the pattern becomes more progressive by late next week. I could see the second half of November get blockier and colder in the east. Link to comment Share on other sites More sharing options...
OKpowdah Posted October 31, 2012 Author Share Posted October 31, 2012 Wouldn't mind seeing that s/w ridge over the Midwest get suppressed a little bit... Link to comment Share on other sites More sharing options...
andyhb Posted November 1, 2012 Share Posted November 1, 2012 Also, on the lighter side of things, the met at Kiro 7 was wearing a tornado costume for Hallowe'en.... Link to comment Share on other sites More sharing options...
andyhb Posted November 1, 2012 Share Posted November 1, 2012 Also, the GFS still shows the post-truncation period system. Edit: I wonder how many limbs the chasers would sacrifice for something like the 00z GFS to verify... Link to comment Share on other sites More sharing options...
Minnesota Meso Posted November 1, 2012 Share Posted November 1, 2012 GFS has had this for at least 4 runs in a row now. In addition to essentially all of the ensembles. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted November 1, 2012 Share Posted November 1, 2012 GFS has had this for at least 4 runs in a row now. In addition to essentially all of the ensembles. Add one more model, the control run of the Euro for it's ensemble members. I was hesitant to start a new thread until the 240hr Euro showed something more solid. Link to comment Share on other sites More sharing options...
andyhb Posted November 1, 2012 Share Posted November 1, 2012 Add one more model, the control run of the Euro for it's ensemble members. I was hesitant to start a new thread until the 240hr Euro showed something more solid. Well yeah, it's really far out, but it's something to keep an eye on. Keep in mind that this would be around the 10th anniversary of the Veterans Day Weekend Outbreak of 2002. Link to comment Share on other sites More sharing options...
brettjrob Posted November 1, 2012 Share Posted November 1, 2012 Also, the GFS still shows the post-truncation period system. It has been fairly consistent and indicative of something worth watching, including tonight's run. Brings the 60 F sfc isodrosotherm up into IA/NE ahead of the ejection, with a couple days of antecedent ridging. Will need to watch the ECMWF and GGEM over the next few days for some further support. While the operational GFS is rarely your go-to guidance for details like timing and thermodynamics in the medium range, my subjective impression over the years has been that it's fairly good about correctly depicting the generalities of major western troughs in this (D10-14) range, especially with this type of consistency. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted November 1, 2012 Share Posted November 1, 2012 The increase in AAM occurring now seems to be mostly located in the subtropics, and is probably related to the coinciding increase in blocking. I think in the next 10 days we'll see the MT AAM anomalies propagated poleward, combined with the FT anomalies around 60N = a big increase in the AO, which we see in the GEFS. This also coincides with the MJO weakening, and cycling across the Indian Ocean. So I think at the very least, the pattern becomes more progressive by late next week. I could see the second half of November get blockier and colder in the east. Wxwatcher91....Question for you. Looking at the current SST's between Greenland and Eastern Canada which are showing much above normal, the same thing over Hudson Bay. How far west could the negative west based NAO be? Could it set up further west than the southern tip of Greenland from which I have been able to read is normal? Link to comment Share on other sites More sharing options...
prinsburg_wx Posted November 1, 2012 Share Posted November 1, 2012 It has been fairly consistent and indicative of something worth watching, including tonight's run. Brings the 60 F sfc isodrosotherm up into IA/NE ahead of the ejection, with a couple days of antecedent ridging. Will need to watch the ECMWF and GGEM over the next few days for some further support. While the operational GFS is rarely your go-to guidance for details like timing and thermodynamics in the medium range, my subjective impression over the years has been that it's fairly good about correctly depicting the generalities of major western troughs in this (D10-14) range, especially with this type of consistency. 0z CMC/GGEM has the system at day 10. Link to comment Share on other sites More sharing options...
Minnesota Meso Posted November 1, 2012 Share Posted November 1, 2012 Looking at the summer/fall years 1952, 1960, and 06, there are some similarities, in particular a weak El Nino, with a -PDO and postive AMO as we headed into the winter season. What is different is the Sea Surface Temps, this year they are much warmer than what was shown in those three years. The winters of 52/53,60/61 and 06/07 had snowfall at MSP in mid 40" range. I'm torn with my winter forecast to be near normal ,45" or above normal say 58". At this time I don't see much of chance of below normal snowfall. Link to comment Share on other sites More sharing options...
andyhb Posted November 1, 2012 Share Posted November 1, 2012 Looks like the Euro is still on board too, albeit further north. Also, the agreement on the GFS ensembles is crazy for this far out. Link to comment Share on other sites More sharing options...
andyhb Posted November 1, 2012 Share Posted November 1, 2012 All three models on board once again for 12z. Link to comment Share on other sites More sharing options...
brettjrob Posted November 1, 2012 Share Posted November 1, 2012 All three models on board once again for 12z. ECMWF has gone back to the somewhat-junky look with lower amplitude, while the GFS and its ensembles are full bore ahead carving out a major, slow-moving trough into the Four Corners states. Link to comment Share on other sites More sharing options...
MnWeatherman Posted November 1, 2012 Share Posted November 1, 2012 1000+ CAPE in southern MN on November 10th? Never chased in November before, definitely something a brew'n. Link to comment Share on other sites More sharing options...
MnWeatherman Posted November 1, 2012 Share Posted November 1, 2012 ECMWF has gone back to the somewhat-junky look with lower amplitude, while the GFS and its ensembles are full bore ahead carving out a major, slow-moving trough into the Four Corners states. Junky? Disagree. GFS and ECMWF are both showing similar temperature advection scenarios, along with the 50+kt low level jet. Even with the lower amplitude, it doesn't necessarily cut down its raw power. Link to comment Share on other sites More sharing options...
brettjrob Posted November 1, 2012 Share Posted November 1, 2012 Junky? Disagree. GFS and ECMWF are both showing similar temperature advection scenarios, along with the 50+kt low level jet. Even with the lower amplitude, it doesn't necessarily cut down its raw power. As usual, I'm biased toward looking for tornadic supercell ingredients (in whatever capacity that's possible at this range). The flat ECMWF solution is unlikely to yield strong backing in the low-levels over the warm sector, relative to the GFS. No doubt, both still produce a formidable cyclone with some severe potential. Link to comment Share on other sites More sharing options...
Chinook Posted November 1, 2012 Share Posted November 1, 2012 I am seeing some consistency with the GFS in the 10-day type range with a trough in the Rockies (Utah area). This could mean some cold and snow for me! You guys are talking about severe weather in the North?????? I used to think tornadoes were impossible in November... and then there was Van Wert. Link to comment Share on other sites More sharing options...
Buckeye05 Posted November 1, 2012 Share Posted November 1, 2012 I am seeing some consistency with the GFS in the 10-day type range with a trough in the Rockies (Utah area). This could mean some cold and snow for me! You guys are talking about severe weather in the North?????? I used to think tornadoes were impossible in November... and then there was Van Wert. Huh? November is one of the most active months for tornadoes, and sometimes called the "second season" Since 2001, only the years 2003, 2007, and 2009 have escaped a notable outbreak or tornadic event of some kind during the month of November. Link to comment Share on other sites More sharing options...
brettjrob Posted November 1, 2012 Share Posted November 1, 2012 Huh? November is one of the most active months for tornadoes, and sometimes called the "second season" Since 2001, only the years 2003, 2007, and 2009 have escaped a notable outbreak or tornadic event of some kind during the month of November. He probably meant outside Dixie Alley and the Southeast. No denying that the late autumn period strongly favors that region. Significant events in the Plains like last year (Nov 7) are rather anomalous. Probably a bit less so in the Midwest, but still hardly a year-to-year event. Link to comment Share on other sites More sharing options...
andyhb Posted November 2, 2012 Share Posted November 2, 2012 ECMWF has gone back to the somewhat-junky look with lower amplitude, while the GFS and its ensembles are full bore ahead carving out a major, slow-moving trough into the Four Corners states. Yeah, for you. Also, what I don't want to see is this becoming some slow moving meridional slop with the ridge becoming too amplified ala 3/18-19. GFS still looks nice though. Link to comment Share on other sites More sharing options...
andyhb Posted November 2, 2012 Share Posted November 2, 2012 00z GFS still on it, albeit the timing is a bit different (which is to be expected most certainly at this range). Link to comment Share on other sites More sharing options...
brettjrob Posted November 2, 2012 Share Posted November 2, 2012 Yeah, for you. Also, what I don't want to see is this becoming some slow moving meridional slop with the ridge becoming too amplified ala 3/18-19. GFS still looks nice though. I hear ya, but the painful truth is that 3/18 with its lone three-hour-long supercell in SW OK was one of the better events this year for the Southern Plains. There was a period for a few years in the past where I hated nothing more than meridional setups. But 2012 has made me care less about that and more about just getting the energy to eject cleanly over the warm sector, instead of skimming north/west in an anafrontal fashion... regardless of orientation. The model consensus for this system doesn't look especially promising in that regard, either, and the 00z GFS seems to be hedging slightly more that way vs. its earlier runs. Baroclinicity... it's fundamental. Link to comment Share on other sites More sharing options...
andyhb Posted November 2, 2012 Share Posted November 2, 2012 Well the Euro/CMC to a lesser extent say goodbye to a clean ejection, for now. Also, keep in mind that this is a possible transition event, so the models will likely have more problems than normal resolving it. Regardless, with the amount of energy progged to move SSE from the NE Pacific next week, this needs to be closely monitored, because, as highlighted above, the teleconnections would likely support an increase in activity during this timeframe. Link to comment Share on other sites More sharing options...
andyhb Posted November 2, 2012 Share Posted November 2, 2012 The H5 pattern on the 12z GFS reminds me very strongly of one of the Euro runs prior to 4/14, although the increasing trend (as can be seen in the 12z GFS ensemble) in problems getting the trough to eject in a timely manner and not getting somewhat strung out (as with like every other larger scale western system this year, it seems like) is beginning to concern me. Link to comment Share on other sites More sharing options...
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