Darrin Rasberry
More time to kill, so I want to open myself to criticism over my current notions about elevated convection. Feel free to instruct and correct any (if not all) that you see are false notions.
True or False:
*An elevated storm is a storm whose inflow air is based somewhere significantly above the surface.
*Therefore inflow will not adversely contribute to any surface wind patterns near or directly underneath the base from which it is drawn.
*Elevated storms may happen over outflow from previous storms given a lifting source (whether the outflow's boundary itself, front, shortwave, dryline, etc.) and given that the air within the outflow has not recovered to the point which it is unstable enough to be drawn.
*The SPC Mesoanalysis Page's LPL (lifted parcel level) effectively and accurately points to areas in which storms passing over it must draw their air above the ground (and therefore most likely elevated).
*Storms may move from elevated to non-elevated (or vice versa) by means of changes in the surface air mass over which it flows.
*For examples of the previous notion, a storm passing from a surface-unstable mass over a warm front, in which the warm air is lifted in upslope regime over the attendant cold air, will become elevated; a surfaced-based storm during the day may turn elevated if the lack of surface heating (attendant to the absence of sunshine on the ground) sufficiently stabilizes the PBL; similarly, a night-time elevated storm surviving the morning may turn surfaced based with surface destabilization caused by daytime heating.
*Elevated storms will never produce a tornado by definition. If a storm labeled as elevated produces a tornado, that means the storm has become surfaced-based.
*Conceivably, funnels may descend to the inflow layer in an elevated storm with sufficiently balanced and powerful wall cloud/mesocyclone. However they do not (at least to my knowledge) due to the lack of "height" below the cloud layer for which to tap inflow.
*Elevated storms may be based above the cap, like those which develop "in front of" warm fronts - the warm air blown from the trailing unstable air mass provides a source of lift as the winds blast it over the front and physics makes that air buoyant, creating both a strong cap over a typically stable PBL and the aforementioned storms simultaneously.
*Another possibility for the creation of elevated convection would be a lifting mechanism initiating convection at midnight. Given that the remnant air itself is sufficiently stabilized on the PBL, the lifting mechanism will therefore reach for perhaps still-unstable air aloft. Here the entire process of convection, from creation through evolution, occurs in an elevated sense given a persistent stable PBL.
*Elevated storms may be either high-based or not high based (base referring to the base of the clouds in this sense for "high based").
*A thunderstorm always has inflow to some degree at some part of the storm (or storm cluster/MCS). This lasts, however great or small, until the last cumulus comprising the storm's remnants dissipates.
*SBCAPE represents the potential energy experienced by parcels near the surface (average of parcels from each height up to 50mb). In a capped environment which a lifting mechanism enters and which PBL solar heating is to be the hammer that "breaks" the inhibition, SBCAPE will be realized at the onset of intitiation, since higher parcels in the moist layer ready for tapping may themselves still be capped while the surface and near-surface parcels are utilized.
*MLCAPE is useful in situations where the unstable parcels from the surface through a significantly deep low-level layer may be tapped without capping interference. If the cap is very weak in a typical unstable air mass, it is MLCAPE that will be realized, since it averages the potential energy that all these tapped particles will experience in updrafts.
*If SBCAPE exists where MLCAPE is very very low, this could very well mean that any convection which develops from the warm surface parcels breaking the CAP could quickly fall to pieces once higher parcels are able to break the CAP and become available for updrafts. Such a situation likely means humidity at the surface is not very deep, or else that a dryline is about to mix out the area.
*MUCAPE examines that parcel in the lowest 300mb which has the highest virtual temperature when it is theoretically "brought to the surface." The CAPE is measured from its height (the LPL or Lifted Parcel Level). This does not mean the parcel produces the highest possible numerical CAPE.
*MUCAPE is useful only when determining the instability on which elevated convection (detectable with a significantly high LPL) feeds, because it will necessarily ignore possible stable layers underneath the LPL. Should storms obviously be surfaced-based on a given day, SBCAPE and MLCAPE should be used instead, as they are averages which necessarily include MUCAPE anyway.
*Likewise when determining instability available to elevated convection SBCAPE and MLCAPE are worthless, unless a reason for the storm to become surface-based exists.
*There is no good forecasting model that predicts the LPL long range. Chasers must rely on typical patterns to predict which initiation will be elevated and where it will not be elevated.
That's all that I can think of. Thanks in advance for any of these you choose to tackle!
True or False:
*An elevated storm is a storm whose inflow air is based somewhere significantly above the surface.
*Therefore inflow will not adversely contribute to any surface wind patterns near or directly underneath the base from which it is drawn.
*Elevated storms may happen over outflow from previous storms given a lifting source (whether the outflow's boundary itself, front, shortwave, dryline, etc.) and given that the air within the outflow has not recovered to the point which it is unstable enough to be drawn.
*The SPC Mesoanalysis Page's LPL (lifted parcel level) effectively and accurately points to areas in which storms passing over it must draw their air above the ground (and therefore most likely elevated).
*Storms may move from elevated to non-elevated (or vice versa) by means of changes in the surface air mass over which it flows.
*For examples of the previous notion, a storm passing from a surface-unstable mass over a warm front, in which the warm air is lifted in upslope regime over the attendant cold air, will become elevated; a surfaced-based storm during the day may turn elevated if the lack of surface heating (attendant to the absence of sunshine on the ground) sufficiently stabilizes the PBL; similarly, a night-time elevated storm surviving the morning may turn surfaced based with surface destabilization caused by daytime heating.
*Elevated storms will never produce a tornado by definition. If a storm labeled as elevated produces a tornado, that means the storm has become surfaced-based.
*Conceivably, funnels may descend to the inflow layer in an elevated storm with sufficiently balanced and powerful wall cloud/mesocyclone. However they do not (at least to my knowledge) due to the lack of "height" below the cloud layer for which to tap inflow.
*Elevated storms may be based above the cap, like those which develop "in front of" warm fronts - the warm air blown from the trailing unstable air mass provides a source of lift as the winds blast it over the front and physics makes that air buoyant, creating both a strong cap over a typically stable PBL and the aforementioned storms simultaneously.
*Another possibility for the creation of elevated convection would be a lifting mechanism initiating convection at midnight. Given that the remnant air itself is sufficiently stabilized on the PBL, the lifting mechanism will therefore reach for perhaps still-unstable air aloft. Here the entire process of convection, from creation through evolution, occurs in an elevated sense given a persistent stable PBL.
*Elevated storms may be either high-based or not high based (base referring to the base of the clouds in this sense for "high based").
*A thunderstorm always has inflow to some degree at some part of the storm (or storm cluster/MCS). This lasts, however great or small, until the last cumulus comprising the storm's remnants dissipates.
*SBCAPE represents the potential energy experienced by parcels near the surface (average of parcels from each height up to 50mb). In a capped environment which a lifting mechanism enters and which PBL solar heating is to be the hammer that "breaks" the inhibition, SBCAPE will be realized at the onset of intitiation, since higher parcels in the moist layer ready for tapping may themselves still be capped while the surface and near-surface parcels are utilized.
*MLCAPE is useful in situations where the unstable parcels from the surface through a significantly deep low-level layer may be tapped without capping interference. If the cap is very weak in a typical unstable air mass, it is MLCAPE that will be realized, since it averages the potential energy that all these tapped particles will experience in updrafts.
*If SBCAPE exists where MLCAPE is very very low, this could very well mean that any convection which develops from the warm surface parcels breaking the CAP could quickly fall to pieces once higher parcels are able to break the CAP and become available for updrafts. Such a situation likely means humidity at the surface is not very deep, or else that a dryline is about to mix out the area.
*MUCAPE examines that parcel in the lowest 300mb which has the highest virtual temperature when it is theoretically "brought to the surface." The CAPE is measured from its height (the LPL or Lifted Parcel Level). This does not mean the parcel produces the highest possible numerical CAPE.
*MUCAPE is useful only when determining the instability on which elevated convection (detectable with a significantly high LPL) feeds, because it will necessarily ignore possible stable layers underneath the LPL. Should storms obviously be surfaced-based on a given day, SBCAPE and MLCAPE should be used instead, as they are averages which necessarily include MUCAPE anyway.
*Likewise when determining instability available to elevated convection SBCAPE and MLCAPE are worthless, unless a reason for the storm to become surface-based exists.
*There is no good forecasting model that predicts the LPL long range. Chasers must rely on typical patterns to predict which initiation will be elevated and where it will not be elevated.
That's all that I can think of. Thanks in advance for any of these you choose to tackle!
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