andyhb Posted June 19, 2012 Share Posted June 19, 2012 The dry EMLs have actually been one of the reasons for events not busting further east (i.e. east of the Plains and especially east of the Mississippi) over the past couple of years, suppressing junk convection, the night before March 2nd this year was a good example, as a strong/dry EML overspread the warm sector and limited organized DMC along the northward moving warm front in the early morning hours so that supercells could organize later on. Link to comment Share on other sites More sharing options...
andyhb Posted June 19, 2012 Share Posted June 19, 2012 Cap may not directly be the issue. CINH has apparently eroded for quite a few events this year where convection failed to form. I think in many of these events with warmer 700 mb temps, 0 CINH isn't enough for CI. As shallow convection (i.e. shallow CU field) encounters a warm EML, mixing of dry air parcels with moist ascending air usually kills initial convective plumes. In situations where CI occurs, subsequent plumes gradually moisten the mid-level environment and allow for eventual sustained deep convection. Many of the events this year have failed to reach this point, which suggests to me very dry EMLs are have been the issue this year more so than the cap "failing to break" (which terminologically suggests that CINH remained nonzero). In a synoptic scale sense, i suspect this has to do with many upper level disturbances this year having neutral or positive tilt, which will generally result in upper level forcing displaced to the N and W of the warm sector (and subsequent upper level "support" in eroding EMLs). If there was ever a year to make me dislike positive tilt configurations, this would be it... Link to comment Share on other sites More sharing options...
jpeters3 Posted June 19, 2012 Share Posted June 19, 2012 Reed needs to learn how to not wishcast... Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2012 Share Posted June 20, 2012 The dry EMLs have actually been one of the reasons for events not busting further east (i.e. east of the Plains and especially east of the Mississippi) over the past couple of years, suppressing junk convection, the night before March 2nd this year was a good example, as a strong/dry EML overspread the warm sector and limited organized DMC along the northward moving warm front in the early morning hours so that supercells could organize later on. yeah, obviously you gotta play with it in most big events.. but in the plains it's been more of an issue. not that it's terribly unusual to have eml problems in the northern plains during summer. Link to comment Share on other sites More sharing options...
jpeters3 Posted June 20, 2012 Share Posted June 20, 2012 The dry EMLs have actually been one of the reasons for events not busting further east (i.e. east of the Plains and especially east of the Mississippi) over the past couple of years, suppressing junk convection, the night before March 2nd this year was a good example, as a strong/dry EML overspread the warm sector and limited organized DMC along the northward moving warm front in the early morning hours so that supercells could organize later on. This is a good point, a strong/dry EML certainly isn't always a bad thing - I think this in combination of the particular synoptic organization of this year's events has resulted in many busts. Edit: I have to be careful with my usage of the word "bust" here. When I say bust, i am referring to setups like this one where tornado parameters max out in the warm sector (usually near the warm front triple point) but CI does not occur in the maxed out region. I am not referring to high end SPC forecasts that fail to materialize. Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2012 Share Posted June 20, 2012 Reed needs to learn how to not wishcast... his whole crew is babbling nonsense. "biggest outbreak since april 14 coming". tell that to the potential on other days that fell flat on their faces. it might happen but it was a lot better for their image when we just saw them finding tornadoes on tv rather than imagining them around every corner. Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 20, 2012 Share Posted June 20, 2012 Reed needs to learn how to not wishcast... He's a PPV service now. He has to constantly pump things up regardless of how bad they actually look. (IMO) Because of this, he is no longer a reliable source. Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2012 Share Posted June 20, 2012 The dry EMLs have actually been one of the reasons for events not busting further east (i.e. east of the Plains and especially east of the Mississippi) over the past couple of years, suppressing junk convection, the night before March 2nd this year was a good example, as a strong/dry EML overspread the warm sector and limited organized DMC along the northward moving warm front in the early morning hours so that supercells could organize later on. Yep that's pretty much it. EML has been favorable for east-of-Plains events, unfavorable for Plains events. The difference is, in 2011 we had strong, dynamic systems, whereas this year the jet stream gave up after April. Link to comment Share on other sites More sharing options...
andyhb Posted June 20, 2012 Share Posted June 20, 2012 Lol biggest outbreak since 4/14.... Yes, looking at EHI maps isn't the only thing to take into consideration... Link to comment Share on other sites More sharing options...
andyhb Posted June 20, 2012 Share Posted June 20, 2012 Yep that's pretty much it. EML has been favorable for east-of-Plains events, unfavorable for Plains events. The difference is, in 2011 we had strong, dynamic systems, whereas this year the jet stream gave up after April. To be honest, in the SE, there have really been very few true "busts" over the past number of years. Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2012 Share Posted June 20, 2012 To be honest, in the SE, there have really been very few true "busts" over the past number of years. I would agree with this. I remember a good number of busts in SE prior to 2006, due to crapvection. This really has been much less of a problem in recent years. (If anything, more recent busts have been more the result of a lack of convection rather than an excess of it.) Link to comment Share on other sites More sharing options...
andyhb Posted June 20, 2012 Share Posted June 20, 2012 A system (particularly in the mid/upper levels) like 4/10/08 most times would produce a very large event, although that had several things outside of the kinematics and relative synoptics working against it (the overall synoptic system was pretty nuts). Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2012 Share Posted June 20, 2012 Cap may not directly be the issue. CINH has apparently eroded for quite a few events this year where convection failed to form. I think in many of these events with warmer 700 mb temps, 0 CINH isn't enough for CI. As shallow convection (i.e. shallow CU field) encounters a warm EML, mixing of dry air parcels with moist ascending air usually kills initial convective plumes. In situations where CI occurs, subsequent plumes gradually moisten the mid-level environment and allow for eventual sustained deep convection. Many of the events this year have failed to reach this point, which suggests to me very dry EMLs are have been the issue this year more so than the cap "failing to break" (which terminologically suggests that CINH remained nonzero). In a synoptic scale sense, i suspect this has to do with many upper level disturbances this year having neutral or positive tilt, which will generally result in upper level forcing displaced to the N and W of the warm sector (and subsequent upper level "support" in eroding EMLs). Good point. I would argue further that the drought has expanded further north this year. Because the jet stream is also further north, it's been picking up drought-enhanced EML's from CO & vicinity. Furthermore, because of the expansion of drought areas, moisture has had a propensity of mixing out, making tornadogenesis that much more difficult, not to mention supercell genesis. Link to comment Share on other sites More sharing options...
jpeters3 Posted June 20, 2012 Share Posted June 20, 2012 Good point. I would argue further that the drought has expanded further north this year. Because the jet stream is also further north, it's been picking up drought-enhanced EML's from CO & vicinity. Furthermore, because of the expansion of drought areas, moisture has had a propensity of mixing out, making tornadogenesis that much more difficult, not to mention supercell genesis. Think about this too - for neutral-to-positively tilted upper level systems, 700-500 hPa flow tends to have a more southeasterly component than for negatively tilted systems. This equates to warmer and drier 700-500 hPa air originating more directly from the intermountain west. Link to comment Share on other sites More sharing options...
Indystorm Posted June 20, 2012 Share Posted June 20, 2012 Yes, the EML has played a significant role in many of the historic outbreaks east of the Mississippi. We shall see what happens in MN this evening. Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2012 Share Posted June 20, 2012 looks like some sustained convection might be getting going in the warm sector now Link to comment Share on other sites More sharing options...
tornadotony Posted June 20, 2012 Share Posted June 20, 2012 looks like some sustained convection might be getting going in the warm sector now The storm on the Lac qui Parle/Chippewa County line might be the real deal if it can sustain itself. Link to comment Share on other sites More sharing options...
jpeters3 Posted June 20, 2012 Share Posted June 20, 2012 looks like some sustained convection might be getting going in the warm sector now Yup, if these little cells going up are sfc based we might be in trouble! Link to comment Share on other sites More sharing options...
Indystorm Posted June 20, 2012 Share Posted June 20, 2012 Keeping an eye on that incipient cell west of Willmar to see if it's the real deal. Link to comment Share on other sites More sharing options...
andyhb Posted June 20, 2012 Share Posted June 20, 2012 Raw parameters certainly are impressive around those things. The storm on Stanga's cam has a nice, low base. Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2012 Share Posted June 20, 2012 just need the storm ne of montevideo to congeal a bit. looks like the central updraft is getting sucked into the lead one. Link to comment Share on other sites More sharing options...
andyhb Posted June 20, 2012 Share Posted June 20, 2012 That storm is in a great environment, dews over 70 degrees, 0-3 km EHI of 7-8 (300-400 m2/s2 effective SRH) and little to no SB or ML CINH. Probably the best out of any of the storms in the area. It's definitely trying to organize, although it looks a little high based still, based on the live streams. Link to comment Share on other sites More sharing options...
jpeters3 Posted June 20, 2012 Share Posted June 20, 2012 I would suggest that cells are initiating above sfc based inhibition (elevated); however, there doesn't appear to be a distinct triggering mechanism for elevated convection - LCLs are are 750 - 1000 m, so perhaps that is why the base looks high? Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2012 Share Posted June 20, 2012 it looks kinda crappy Link to comment Share on other sites More sharing options...
andyhb Posted June 20, 2012 Share Posted June 20, 2012 it looks kinda crappy Yeah, kinda fell apart. Link to comment Share on other sites More sharing options...
Ian Posted June 20, 2012 Share Posted June 20, 2012 MESOSCALE DISCUSSION 1226 NWS STORM PREDICTION CENTER NORMAN OK 0912 PM CDT TUE JUN 19 2012 AREAS AFFECTED...ERN SD THRU CNTRL MN CONCERNING...TORNADO WATCH 413... VALID 200212Z - 200345Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 413 CONTINUES. SUMMARY...THE RISK FOR LARGE HAIL AND DAMAGING WIND GUSTS MAY BECOME THE PRIMARY SEVERE THREATS...BUT SUPERCELL DEVELOPMENT WITH TORNADO POTENTIAL STILL CANNOT BE RULED OUT THIS EVENING. DISCUSSION...THE EASTERN SOUTH DAKOTA SURFACE LOW CENTER HAS BEGUN TO WEAKEN. MODELS INDICATE THAT THIS FEATURE MAY MIGRATE NORTHEASTWARD ALONG THE FRONTAL ZONE INTO WEST CENTRAL MINNESOTA DURING THE 03-05Z TIME FRAME. BUT THE SOUTHWESTERLY 850 MB JET IS STILL EXPECTED TO STRENGTHEN FROM 40-50+ KT...INCREASING LOW-LEVEL SHEAR WITHIN THE WARM SECTOR AND ALONG THE WARM FRONTAL ZONE ACROSS SOUTHEASTERN SOUTH DAKOTA NORTHWARD THROUGH CENTRAL MINNESOTA. THE PRIMARY LIMITING FACTOR CONCERNING CONVECTIVE DEVELOPMENT AND SEVERE WEATHER POTENTIAL REMAINS THE STRONG CAPPING BENEATH VERY WARM ELEVATED MIXED LAYER AIR. AS THE WARM SECTOR BOUNDARY LAYER BEGINS TO SLOWLY COOL...HIGHEST PROBABILITIES FOR NEW CONVECTIVE DEVELOPMENT SEEM TO REMAIN IN A CORRIDOR OF STRONGER FORCING ABOVE/NORTH OF THE WARM FRONT...IN CLOSER PROXIMITY TO INFLOW OF AIR EMANATING FROM THE MOIST WARM SECTOR BOUNDARY LAYER CHARACTERIZED BY SURFACE DEW POINTS NEAR 70F. Link to comment Share on other sites More sharing options...
thewxmann Posted June 20, 2012 Share Posted June 20, 2012 As is usual during cap busts, oh so close, yet so far. (You can see the inversions at 650 and 750 mb.) And actually the EML isn't all that dry, surprising enough. Link to comment Share on other sites More sharing options...
jpeters3 Posted June 20, 2012 Share Posted June 20, 2012 As is usual during cap busts, oh so close, yet so far. (You can see the inversions at 650 and 750 mb.) And actually the EML isn't all that dry, surprising enough. Again, wouldn't call it a "cap bust," because there isn't any cap in this sounding. Link to comment Share on other sites More sharing options...
Indystorm Posted June 20, 2012 Share Posted June 20, 2012 Maybe we need to coin a new phrase, like EML suppression. Link to comment Share on other sites More sharing options...
jojo762 Posted June 20, 2012 Share Posted June 20, 2012 Overall, I'm a bit confused to the overall difference between CINH and EML in the Plains. They both seem to serve the same purpose, and do the same things IMO... Although as previously posted there is a bit of a difference of EML in the SE and EML in the Plains... EDIT: In other words EML and CINH both act as a cap in the Plains... Link to comment Share on other sites More sharing options...
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