List of convective parameters and other important details

Bartosz Czernecki, Mateusz Taszarek, Piotr Szuster

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All CAPE parameters are calculated by integrating parcel’s positive buoyancy between level of free convection (LFC) and equilibrium level (EL). All CIN parameters are calculated by integrating parcel negative buoyancy between parcel initialization height and level of free convection (LFC). Most-unstable (MU) parcel is defined based on the highest theta-e between surface and 3 km above ground level (AGL). A default mixed-layer (ML) parcel is calculated by averaging theta and mixing ratio over 0–500 m AGL layer and initializing from surface. If other user-defined parcel lifting options are choosen, all parameters that use mixed-layer (ML) parcel (e.g. STP_new) will now use a user-defined manual-lift (ML) parcel.

Computed parameters:

Below is the full list of parameters computed and exported with the sounding_compute() function:

Parcel parameters

[1] MU_CAPE – convective available potential energy, derived from the most-unstable parcel. Units are J/kg.

[2] MU_CAPE_M10 – convective available potential energy in the temperature below -10°C, derived from the most-unstable parcel. Units are J/kg.

[3] MU_CAPE_M10_PT – convective available potential energy in the parcel temperature below - 10°C, derived from the most-unstable parcel. Units are J/kg.

[4] MU_02km_CAPE – convective available potential energy between surface and 2 km AGL, derived from the most-unstable parcel. Units are J/kg.

[5] MU_03km_CAPE – convective available potential energy between surface and 3 km AGL, derived from the most-unstable parcel. Units are J/kg.

[6] MU_HGL_CAPE – convective available potential energy in a hail growth layer (between 0°C and −20°C), derived from the most-unstable parcel. Units are J/kg.

[7] MU_CIN – convective inhibition, derived from the most-unstable parcel. Units are J/kg.

[8] MU_LCL_HGT – height of the lifted condensation level, derived from the most-unstable parcel. Units are m AGL.

[9] MU_LFC_HGT – height of the level of free convection, derived from the most-unstable parcel. Units are m AGL.

[10] MU_EL_HGT – height of the equilibrium level, derived from the most-unstable parcel. Units are m AGL.

[11] MU_LI – lifted index (at 500 hPa), derived from the most-unstable parcel. Units are K.

[12] MU_LI_M10 – lifted index (at -10°C), derived from the most-unstable parcel. Units are K.

[13] MU_WMAX – estimated updraft speed (a square root of two times CAPE), derived from the most-unstable parcel. Units are m/s.

[14] MU_EL_TEMP – temperature of the equilibrium level, derived from the most-unstable parcel. Units are °C.

[15] MU_LCL_TEMP – temperature of the lifted condensation level, derived from the most- unstable parcel. Units are °C.

[16] MU_LFC_TEMP – temperature of the level of free convection, derived from the most- unstable parcel. Units are °C.

[17] MU_MIXR – mixing ratio at the height of the most-unstable parcel. Units are g/kg.

[18] MU_CAPE_500 – convective available potential energy, derived from the most-unstable parcel excluding lowest 500 m AGL. Units are J/kg.

[19] MU_CAPE_500_M10 – convective available potential energy in the temperature below - 10°C, derived from the most-unstable parcel excluding lowest 500 m AGL. Units are J/kg.

[20] MU_CAPE_500_M10_PT – convective available potential energy in the parcel temperature below -10°C, derived from the most-unstable parcel excluding lowest 500 m AGL. Units are J/kg.

[21] MU_CIN_500 – convective inhibition, derived from the most-unstable parcel excluding lowest 500 m AGL. Units are J/kg.

[22] MU_LI_500 – lifted index (500 hPa), derived from the most-unstable parcel excluding lowest 500 m AGL. Units are K.

[23] MU_LI_500_M10 – lifted index (at -10°C), derived from the most-unstable parcel excluding lowest 500 m AGL. Units are K.

[24] SB_CAPE – convective available potential energy, derived from the surface-based parcel. Units are J/kg.

[25] SB_CAPE_M10 – convective available potential energy in the temperature below -10°C, derived from the surface-based parcel. Units are J/kg.

[26] SB_CAPE_M10_PT – convective available potential energy in the parcel temperature below - 10°C, derived from the surface-based parcel. Units are J/kg.

[27] SB_02km_CAPE – convective available potential energy between surface and 2 km AGL, derived from the surface-based parcel. Units are J/kg.

[28] SB_03km_CAPE – convective available potential energy between surface and 3 km AGL, derived from the surface-based parcel. Units are J/kg.

[29] SB_HGL_CAPE – convective available potential energy in a hail growth layer (between 0°C and −20°C), derived from the surface-based parcel. Units are J/kg.

[30] SB_CIN – convective inhibition, derived from the surface-based parcel. Units are J/kg.

[31] SB_LCL_HGT – height of the lifted condensation level, derived from the surface-based parcel. Units are m AGL.

[32] SB_LFC_HGT – height of the level of free convection, derived from the surface-based parcel. Units are m AGL.

[33] SB_EL_HGT – height of the equilibrium level, derived from the surface-based parcel. Units are m AGL.

[34] SB_LI – lifted index (500 hPa), derived from the surface-based parcel. Units are K.

[35] SB_LI_M10 – lifted index (at -10°C), derived from the surface-unstable parcel. Units are K.

[36] SB_WMAX – estimated updraft speed (a square root of two times CAPE), derived from the surface-based parcel. Units are m/s.

[37] SB_EL_TEMP – temperature of the equilibrium level, derived from the surface-based parcel. Units are °C.

[38] SB_LCL_TEMP – temperature of the lifted condensation level, derived from the surface- based parcel. Units are °C.

[39] SB_LFC_TEMP – temperature of the level of free convection, derived from the surface-based parcel. Units are °C.

[40] SB_MIXR – mixing ratio at the height of the surface-based parcel. Units are g/kg.

[41] ML_CAPE – convective available potential energy, derived from the mixed-layer parcel. Units are J/kg.

[42] ML_CAPE_M10 – convective available potential energy in the temperature below -10°C, derived from the mixed-layer parcel. Units are J/kg.

[43] ML_CAPE_M10_PT – convective available potential energy in the parcel temperature below -10°C, derived from the mixed-layer parcel. Units are J/kg.

[44] ML_02km_CAPE – convective available potential energy between surface and 2 km AGL, derived from the mixed-layer parcel. Units are J/kg.

[45] ML_03km_CAPE – convective available potential energy between surface and 3 km AGL, derived from the mixed-layer parcel. Units are J/kg.

[46] ML_HGL_CAPE – convective available potential energy in a hail growth layer (between 0°C and −20°C), derived from the mixed-layer parcel. Units are J/kg.

[47] ML_CIN – convective inhibition, derived from the mixed-layer parcel. Units are J/kg.

[48] ML_LCL_HGT – height of the lifted condensation level, derived from the mixed-layer parcel. Units are m AGL.

[49] ML_LFC_HGT – height of the level of free convection, derived from the mixed-layer parcel. Units are m AGL.

[50] ML_EL_HGT – height of the equilibrium level, derived from the mixed-layer parcel. Units are m AGL.

[51] ML_LI – lifted index, derived from the mixed-layer parcel. Units are K.

[52] ML_LI_M10 – lifted index (at -10°C), derived from the mixed-layer parcel. Units are K.

[53] ML_WMAX – estimated updraft speed (a square root of two times CAPE), derived from the mixed-layer parcel. Units are m/s.

[54] ML_EL_TEMP – temperature of the equilibrium level, derived from the mixed-layer parcel. Units are °C.

[55] ML_LCL_TEMP – temperature of the lifted condensation level, derived from the mixed-layer parcel. Units are °C.

[56] ML_LFC_TEMP – temperature of the level of free convection, derived from the mixed-layer parcel. Units are °C.

[57] ML_MIXR – mixing ratio at the height of the surface-based parcel. Units are g/kg.

Temperature and moisture parameters:

[58] LR_0500m – temperature lapse rate between surface and 500 m AGL. Units are K/km.

[59] LR_01km – temperature lapse rate between surface and 1 km AGL. Units are K/km.

[60] LR_02km – temperature lapse rate between surface and 2 km AGL. Units are K/km.

[61] LR_03km – temperature lapse rate between surface and 3 km AGL. Units are K/km.

[62] LR_04km – temperature lapse rate between surface and 4 km AGL. Units are K/km.

[63] LR_06km – temperature lapse rate between surface and 6 km AGL. Units are K/km.

[64] LR_16km – temperature lapse rate between 1 and 6 km AGL. Units are K/km.

[65] LR_26km – temperature lapse rate between 2 and 6 km AGL. Units are K/km.

[66] LR_24km – temperature lapse rate between 2 and 4 km AGL. Units are K/km.

[67] LR_36km – temperature lapse rate between 3 and 6 km AGL. Units are K/km.

[68] LR_26km_MAX – maximum temperature lapse rate between 2 and 6 km AGL (2 km steps). Units are K/km.

[69] LR_500700hPa – temperature lapse rate between 500 and 700 hPa (if below ground level, the lowest available level is considered). Units are K/km.

[70] LR_500800hPa – temperature lapse rate between 500 and 800 hPa (if below ground level, the lowest available level is considered). Units are K/km.

[71] LR_600800hPa – temperature lapse rate between 600 and 800 hPa (if below ground level, the lowest available level is considered). Units are K/km.

[72] FRZG_HGT – height of freezing level (0°C), as a first available level counting from the surface. Units are m AGL.

[73] FRZG_wetbulb_HGT – height of wet-bulb freezing level (0°C) as a first available level counting from the surface. Units are m AGL.

[74] HGT_max_thetae_03km – height of the highest theta-e between surface and 3 km AGL (defined as most-unstable parcel). Units are m AGL.

[75] HGT_min_thetae_04km – height of the lowest theta-e between surface and 4 km AGL. Units are m AGL.

[76] Delta_thetae – difference in theta-e between the mean in 3–5 km AGL layer and surface. Units are K.

[77] Delta_thetae_04km – difference in theta-e between lowest value in 0–4 km AGL and surface. Units are K.

[78] Thetae_01km – mean theta-e between surface and 1 km AGL. Units are K.

[79] Thetae_02km – mean theta-e between surface and 2 km AGL. Units are K.

[80] DCAPE – downdraft convective available potential energy, initialized from 4 km AGL with a mean theta-e in 3–5 km AGL layer. Units are J/kg.

[81] Cold_Pool_Strength – difference between surface temperature and temperature of the downdraft (derived from DCAPE procedure) at the surface. Units are K.

[82] Wind_Index – based on original formula from McCann (1994), doi: https://doi.org/10.1175/1520-0434(1994)009%3C0532:WNIFFM%3E2.0.CO;2 Units indicate estimated wind gust in knots.

[83] PRCP_WATER – precipitable water (entire column). Units are mm.

[84] Moisture_Flux_02km – mean wind speed multiplied by mean mixing ratio in the layer between surface and 2 km AGL (both). Units are g/s/m2.

[85] RH_01km – mean relative humidity between surface and 1 km AGL layer. Units are %.

[86] RH_02km – mean relative humidity between surface and 2 km AGL layer. Units are %.

[87] RH_14km – mean relative humidity between 1 and 4 km AGL layer. Units are %.

[88] RH_25km – mean relative humidity between 2 and 5 km AGL layer. Units are %.

[89] RH_36km – mean relative humidity between 3 and 6 km AGL layer. Units are %.

[90] RH_HGL – mean relative humidity in a hail growth layer (between 0°C and −20°C). Units are %.

Kinematic parameters:

If user-defined manual storm motion is choosen, all parameters that use RM and LM Bunkers storm-motion vectors will now use a user-defined manual storm motion vector.

[91] BS_0500m – bulk wind shear between surface and 500 m AGL. Units are m/s.

[92] BS_01km – bulk wind shear between surface and 1 km AGL. Units are m/s.

[93] BS_02km – bulk wind shear between surface and 2 km AGL. Units are m/s.

[94] BS_03km – bulk wind shear between surface and 3 km AGL. Units are m/s.

[95] BS_06km – bulk wind shear between surface and 6 km AGL. Units are m/s.

[96] BS_08km – bulk wind shear between surface and 8 km AGL. Units are m/s.

[97] BS_36km – bulk wind shear between 3 and 6 km AGL. Units are m/s.

[98] BS_26km – bulk wind shear between 2 and 6 km AGL. Units are m/s.

[99] BS_16km – bulk wind shear between 1 and 6 km AGL. Units are m/s.

[100] BS_18km – bulk wind shear between 1 and 8 km AGL. Units are m/s.

[101] BS_EFF_MU – effective shear between parcel initialization height and half of the distance to equilibrium level height, based on the most-unstable parcel. Units are m/s.

[102] BS_EFF_SB – effective shear between parcel initialization height and half of the distance to equilibrium level height, based on the surface-based parcel. Units are m/s.

[103] BS_EFF_ML – effective shear between parcel initialization height and half of the distance to equilibrium level height, based on the mixed-layer parcel. Units are m/s.

[104] BS_SFC_to_M10 – bulk wind shear between surface and −10°C. Units are m/s.

[105] BS_1km_to_M10 – bulk wind shear between 1 km AGL and −10°C. Units are m/s.

[106] BS_2km_to_M10 – bulk wind shear between 2 km AGL and −10°C. Units are m/s.

[107] BS_MU_LFC_to_M10 – bulk wind shear between most-unstable level of free convection and −10°C. Units are m/s.

[108] BS_SB_LFC_to_M10 – bulk wind shear between surface-based level of free convection and −10°C. Units are m/s.

[109] BS_ML_LFC_to_M10 – bulk wind shear between mixed-layer level of free convection and −10°C. Units are m/s.

[110] BS_MW02_SM – bulk wind shear between 0–2 km mean wind and mean storm motion vector. Units are m/s.

[111] BS_MW02_RM – bulk wind shear between 0–2 km mean wind and right-moving supercell vector. Units are m/s.

[112] BS_MW02_LM – bulk wind shear between 0–2 km mean wind and left-moving supercell vector. Units are m/s.

[113] BS_HGL_SM – bulk wind shear between a hail growth layer (between 0°C and −20°C) and mean storm motion vector. Units are m/s.

[114] BS_HGL_RM – bulk wind shear between a hail growth layer (between 0°C and −20°C) and right-moving supercell vector. Units are m/s.

[115] BS_HGL_LM – bulk wind shear between a hail growth layer (between 0°C and −20°C) and left-moving supercell vector. Units are m/s.

[116] MW_0500m – mean wind speed between surface and 500 m AGL layer. Units are m/s.

[117] MW_01km – mean wind speed between surface and 1 km AGL layer. Units are m/s.

[118] MW_02km – mean wind speed between surface and 2 km AGL layer. Units are m/s.

[119] MW_03km – mean wind speed between surface and 3 km AGL layer. Units are m/s.

[120] MW_06km – mean wind speed between surface and 6 km AGL layer. Units are m/s.

[121] MW_13km – mean wind speed between 1 and 3 km AGL layer. Units are m/s.

[122] SRH_100m_RM – storm-relative helicity between surface and 100m AGL for right-moving supercell vector. Units are m2/s2.

[123] SRH_250m_RM – storm-relative helicity between surface and 250m AGL for right-moving supercell vector. Units are m2/s2.

[124] SRH_500m_RM – storm-relative helicity between surface and 500m AGL for right-moving supercell vector. Units are m2/s2.

[125] SRH_1km_RM – storm-relative helicity between surface and 1 km AGL for right-moving supercell vector. Units are m2/s2.

[126] SRH_3km_RM – storm-relative helicity between surface and 3 km AGL for right-moving supercell vector. Units are m2/s2.

[127] SRH_36km_RM – storm-relative helicity between 3 and 6 km AGL for right-moving supercell vector. Units are m2/s2.

[128] SRH_100m_LM – storm-relative helicity between surface and 100m AGL for left-moving supercell vector. Units are m2/s2.

[129] SRH_250m_LM – storm-relative helicity between surface and 250m AGL for left-moving supercell vector. Units are m2/s2.

[130] SRH_500m_LM – storm-relative helicity between surface and 500m AGL for left-moving supercell vector. Units are m2/s2.

[131] SRH_1km_LM – storm-relative helicity between surface and 1 km AGL for left-moving supercell vector. Units are m2/s2.

[132] SRH_3km_LM – storm-relative helicity between surface and 3 km AGL for left-moving supercell vector. Units are m2/s2.

[133] SRH_36km_LM – storm-relative helicity between 3 and 6 km AGL for left-moving supercell vector. Units are m2/s2.

[134] SV_500m_RM – streamwise vorticity between surface and 500 m AGL for right-moving supercell vector. Units are 1/s.

[135] SV_01km_RM – streamwise vorticity between surface and 1 km AGL for right-moving supercell vector. Units are 1/s.

[136] SV_03km_RM – streamwise vorticity between surface and 3 km AGL for right-moving supercell vector. Units are 1/s.

[137] SV_500m_LM – streamwise vorticity between surface and 500 m AGL for left-moving supercell vector. Units are 1/s.

[138] SV_01km_LM – streamwise vorticity between surface and 1 km AGL for left-moving supercell vector. Units are 1/s.

[139] SV_03km_LM – streamwise vorticity between surface and 3 km AGL for left-moving supercell vector. Units are 1/s.

[140] MW_SR_500m_RM – storm-relative mean wind between surface and 500 m AGL for right- moving supercell vector. Units are m/s.

[141] MW_SR_01km_RM – storm-relative mean wind between surface and 500 m AGL for right- moving supercell vector. Units are m/s.

[142] MW_SR_03km_RM – storm-relative mean wind between surface and 3 km AGL for right- moving supercell vector. Units are m/s.

[143] MW_SR_500m_LM – storm-relative mean wind between surface and 500 m AGL for left- moving supercell vector. Units are m/s.

[144] MW_SR_01km_LM – storm-relative mean wind between surface and 500 m AGL for left- moving supercell vector. Units are m/s.

[145] MW_SR_03km_LM – storm-relative mean wind between surface and 3 km AGL for left- moving supercell vector. Units are m/s.

[146] MW_SR_VM_500m_RM – storm-relative mean wind (using a mean of vector magnitude) between surface and 500 m AGL for right-moving supercell vector. Units are m/s.

[147] MW_SR_VM_01km_RM – storm-relative mean wind (using a mean of vector magnitude) between surface and 500 m AGL for right-moving supercell vector. Units are m/s.

[148] MW_SR_VM_03km_RM – storm-relative mean wind (using a mean of vector magnitude) between surface and 3 km AGL for right-moving supercell vector. Units are m/s.

[149] MW_SR_VM_500m_LM – storm-relative mean wind (using a mean of vector magnitude) between surface and 500 m AGL for left-moving supercell vector. Units are m/s.

[150] MW_SR_VM_01km_LM – storm-relative mean wind (using a mean of vector magnitude) between surface and 500 m AGL for left-moving supercell vector. Units are m/s.

[151] MW_SR_VM_03km_LM – storm-relative mean wind (using a mean of vector magnitude) between surface and 3 km AGL for left-moving supercell vector. Units are m/s.

[152] SV_FRA_500m_RM – streamwise vorticity between surface and 500 m AGL for right- moving supercell vector. Units are 1/s.

[153] SV_FRA_01km_RM – streamwise vorticity fraction between surface and 1 km AGL for right-moving supercell vector. Units are 1/s.

[154] SV_FRA_03km_RM – streamwise vorticity fraction between surface and 3 km AGL for right-moving supercell vector. Units are 1/s.

[155] SV_FRA_500m_LM – streamwise vorticity fraction between surface and 500 m AGL for left-moving supercell vector. Units are 1/s.

[156] SV_FRA_01km_LM – streamwise vorticity fraction between surface and 1 km AGL for left- moving supercell vector. Units are 1/s.

[157] SV_FRA_03km_LM – streamwise vorticity fraction between surface and 3 km AGL for left- moving supercell vector. Units are 1/s.

[158] Bunkers_RM_A – azimuth for right-moving supercell vector. See Bunkers et al. (2002), doi: https://doi.org/10.1175/1520-0434(2000)015%3C0061:PSMUAN%3E2.0.CO;2 for further details. Units are °.

[159] Bunkers_RM_M – wind speed for right-moving supercell vector. See Bunkers et al. (2002), doi: https://doi.org/10.1175/1520-0434(2000)015%3C0061:PSMUAN%3E2.0.CO;2 for further details. Units are m/s.

[160] Bunkers_LM_A – azimuth for left-moving supercell vector. See Bunkers et al. (2002), doi: https://doi.org/10.1175/1520-0434(2000)015%3C0061:PSMUAN%3E2.0.CO;2 for further details. Units are °.

[161] Bunkers_LM_M – wind speed for left-moving supercell vector. See Bunkers et al. (2002), doi: https://doi.org/10.1175/1520-0434(2000)015%3C0061:PSMUAN%3E2.0.CO;2 for further details. Units are m/s.

[162] Bunkers_MW_A – azimuth for mean storm motion vector. See Bunkers et al. (2002), doi: https://doi.org/10.1175/1520-0434(2000)015%3C0061:PSMUAN%3E2.0.CO;2 for further details. Units are °.

[163] Bunkers_MW_M – wind speed for mean storm motion vector. See Bunkers et al. (2002), doi: https://doi.org/10.1175/1520-0434(2000)015%3C0061:PSMUAN%3E2.0.CO;2 for further details. Units are m/s.

[164] Corfidi_downwind_A – azimuth for Corfidi downwind vector. See Corfidi (2003) doi: https://doi.org/10.1175/1520-0434(2003)018%3C0997:CPAMPF%3E2.0.CO;2 for further details. Units are °.

[165] Corfidi_downwind_M – wind speed for Corfidi downwind vector. See Corfidi (2003) doi: https://doi.org/10.1175/1520-0434(2003)018%3C0997:CPAMPF%3E2.0.CO;2 for further details. Units are m/s.

[166] Corfidi_upwind_A – azimuth for Corfidi upwind vector. See Corfidi (2003) doi: https://doi.org/10.1175/1520-0434(2003)018%3C0997:CPAMPF%3E2.0.CO;2 for further details. Units are °.

[167] Corfidi_upwind_M – wind speed for Corfidi upwind vector. See Corfidi (2003) doi: https://doi.org/10.1175/1520-0434(2003)018%3C0997:CPAMPF%3E2.0.CO;2 for further details. Units are m/s.

Composite parameters:

[168] K_Index – based on original formula from George (1960): “Weather Forecasting for Aeronautics” Academic Press, London, 1960, p. 673. Units are K.

[169] Showalter_Index – based on original formula from Showalter (1953), doi: https://doi.org/10.1175/1520-0477-34.6.250. Units are K.

[170] TotalTotals_Index – based on original formula from Miller (1972): “Notes on analysis and severe-storm forecasting procedures of the Air Force Global Weather Central”, AWS Tech. Rpt. 200(rev), Air Weather Service, Scott AFB, IL. Units are K.

[171] SWEAT_Index – based on original formula from Bidner (1970): “The Air Force Global Weather Central severe weather threat (SWEAT) index—A preliminary report”. Air Weather Service Aerospace Sciences Review, AWS RP 105-2, No. 70-3, 2-5. Parameter is dimensionless.

[172] STP_fix – (significant tornado parameter fixed-layer) based on the fixed layer formula using surface-based CAPE and CIN. Parameter is dimensionless.

[173] STP_new – (significant tornado parameter) based on the formula from Coffer et al. (2019), doi: https://doi.org/10.1175/WAF-D-19-0115.1. Parameter is dimensionless.

[174] STP_fix_LM – (significant tornado parameter fixed-layer) based on the fixed layer formula using surface-based CAPE and CIN. This version uses left-moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Parameter is dimensionless.

[175] STP_new_LM – (significant tornado parameter) based on the formula from Coffer et al. (2019), doi: https://doi.org/10.1175/WAF-D-19-0115.1. This version uses left-moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Parameter is dimensionless.

[176] SCP_fix – (supercell composite parameter fixed-layer) based on Thompson et al. (2007), “An update to the supercell composite and significant tornado parameters”. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc. P (Vol. 8), but with effective SRH replaced with surface to 3 km AGL SRH and effective bulk wind shear replaced with surface to 6 km AGL bulk wind shear. Based on most-unstable CAPE. Parameter is dimensionless.

[177] SCP_new – (supercell composite parameter) based on formula from Gropp and Davenport (2018), doi: https://doi.org/10.1175/WAF-D-17-0150.1, but with effective SRH replaced with surface to 3 km AGL SRH. This version uses effective shear and CIN term. Based on most-unstable parcel. Parameter is dimensionless.

[178] SCP_fix_LM – (supercell composite parameter fixed-layer) based on Thompson et al. (2007), “An update to the supercell composite and significant tornado parameters”. Preprints, 22nd Conf. on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc. P (Vol. 8), but with effective SRH replaced with surface to 3 km AGL SRH and effective bulk wind shear replaced with surface to 6 km AGL bulk wind shear. Based on most-unstable CAPE. This version uses left-moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Parameter is dimensionless.

[179] SCP_new_LM – (supercell composite parameter) based on formula from Gropp and Davenport (2018), doi: https://doi.org/10.1175/WAF-D-17-0150.1, but with effective SRH replaced with surface to 3 km AGL SRH. This version uses effective shear and CIN term. Based on most- unstable parcel. This version uses left-moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Parameter is dimensionless.

[180] SHIP – (significant hail parameter), based on formula currently used on the Storm Prediction Center mesoanalysis (https://www.spc.noaa.gov/exper/mesoanalysis/) as of 1 March 2021. Parameter is dimensionless.

[181] HSI – (hail size index), based on formula from Czernecki et al. (2019), doi: https://doi.org/10.1016/j.atmosres.2019.05.010. Units are cm.

[182] DCP – based on formula currently used on the Storm Prediction Center mesoanalysis (https://www.spc.noaa.gov/exper/mesoanalysis/) as of 1 March 2021. Parameter is dimensionless.

[183] MU_WMAXSHEAR – most-unstable WMAX multiplied by surface to 6 km AGL bulk wind shear. See Taszarek et al. (2020), doi: https://doi.org/10.1175/JCLI-D-20-0346.1 for further details on WMAXSHEAR. Units are m2/s2.

[184] SB_WMAXSHEAR – surface-based WMAX multiplied by surface to 6 km AGL bulk wind shear. See Taszarek et al. (2020), doi: https://doi.org/10.1175/JCLI-D-20-0346.1 for further details on WMAXSHEAR. Units are m2/s2.

[185] ML_WMAXSHEAR – mixed-layer WMAX multiplied by surface to 6 km AGL bulk wind shear. See Taszarek et al. (2020), doi: https://doi.org/10.1175/JCLI-D-20-0346.1 for further details on WMAXSHEAR. Units are m2/s2.

[186] MU_EFF_WMAXSHEAR – most-unstable WMAX multiplied by most-unstable effective bulk wind shear. See Taszarek et al. (2020), doi: https://doi.org/10.1175/JCLI-D-20-0346.1 for further details on WMAXSHEAR. Units are m2/s2.

[187] SB_EFF_WMAXSHEAR – surface-based WMAX multiplied by surface-based effective bulk wind shear. See Taszarek et al. (2020), doi: https://doi.org/10.1175/JCLI-D-20-0346.1 for further details on WMAXSHEAR. Units are m2/s2.

[188] ML_EFF_WMAXSHEAR – mixed-layer WMAX multiplied by mixed-layer effective bulk wind shear. See Taszarek et al. (2020), doi: https://doi.org/10.1175/JCLI-D-20-0346.1 for further details on WMAXSHEAR. Units are m2/s2.

[189] EHI_500m – (energy helicity index), surface-based CAPE multiplied by 0–500 m storm- relative helicity for right-moving supercells and divided by 160000. Units are m2/s2.

[190] EHI_01km – (energy helicity index), surface-based CAPE multiplied by 0–1 km storm- relative helicity for right-moving supercells and divided by 160000. Units are m2/s2.

[191] EHI_03km – (energy helicity index), surface-based CAPE multiplied by 0–3 km storm- relative helicity for right-moving supercells and divided by 160000. Units are m2/s2.

[192] EHI_500m_LM – (energy helicity index), surface-based CAPE multiplied by 0–500 m storm-relative helicity for right-moving supercells and divided by 160000. This version uses left- moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Units are m2/s2.

[193] EHI_01km_LM – (energy helicity index), surface-based CAPE multiplied by 0–1 km storm- relative helicity for right-moving supercells and divided by 160000. This version uses left-moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Units are m2/s2.

[194] EHI_03km_LM – (energy helicity index), surface-based CAPE multiplied by 0–3 km storm- relative helicity for right-moving supercells and divided by 160000. This version uses left-moving supercell vector for SRH calculation and is dedicated for Southern Hemisphere. Units are m2/s2.

[195] SHERBS3 – based on the formula available in Sherburn and Parker (2014), doi: https://doi.org/10.1175/WAF-D-13-00041.1. This version uses 0–3 km bulk wind shear term. Parameter is dimensionless.

[196] SHERBE – based on the formula available in Sherburn and Parker (2014), doi: https://doi.org/10.1175/WAF-D-13-00041.1. This version uses effective bulk wind shear term. Parameter is dimensionless.

[197] SHERBS3_v2 – based on the formula available in Sherburn and Parker (2014), doi: https://doi.org/10.1175/WAF-D-13-00041.1, but with 700-500 hPa lapse rate replaced with maximum 2 km lapse rate between 2 and 6 km AGL. This version uses 0–3 km bulk wind shear term. Parameter is dimensionless.

[198] SHERBE_v2 – based on the formula available in Sherburn and Parker (2014), doi: https://doi.org/10.1175/WAF-D-13-00041.1, but with 700-500 hPa lapse rate replaced with maximum 2 km lapse rate between 2 and 6 km AGL. This version uses effective bulk wind shear term. Parameter is dimensionless.

[199] DEI – (downburst environment index), a composite product of WMAXSHEAR and Cold Pool Strengths, based on the formula available in Romanic et al. (2022), doi: https://doi.org/10.1016/j.wace.2022.100474. Parameter is dimensionless.

[200] DEI_eff – (downburst environment index), a composite product of WMAXSHEAR and Cold Pool Strengths but using an effective bulk wind shear layer, based on the formula available in Romanic et al. (2022), doi: https://doi.org/10.1016/j.wace.2022.100474. Parameter is dimensionless.

[201] TIP – (thunderstorm intensity parameter), an experimental composite product of CAPE, bulk wind shear, precipitable water and storm-relative helicity. Parameter is dimensionless

Accuracy tables for sounding_compute()

The interpolation algorithm used in the sounding_compute() function impacts accuracy of parameters such as CAPE or CIN and the performance of the script. The valid options for the accuracy parameter are 1, 2 or 3:

accuracy = 1 - High performance but low accuracy. Dedicated for large dataset when output data needs to be quickly available (e.g. operational numerical weather models). This option is around 20 times faster than high accuracy (3) setting. Interpolation is peformed for 60 levels (m AGL):

#>  [1]     0   100   200   300   400   500   600   700   800   900  1000  1100
#> [13]  1200  1300  1400  1600  1800  2000  2200  2400  2600  2800  3000  3200
#> [25]  3400  3600  3800  4000  4200  4400  4600  4800  5000  5200  5400  5600
#> [37]  5800  6000  6500  7000  7500  8000  8500  9000  9500 10000 10500 11000
#> [49] 11500 12000 12500 13000 13500 14000 15000 16000 17000 18000 19000 20000

accuracy = 2 - Compromise between script performance and accuracy. Recommended for efficient processing of large numerical weather prediction datasets such as meteorological reanalyses for research studies. This option is around 10 times faster than high accuracy (3) setting. Interpolation is peformed for 318 levels (m AGL):

#>   [1]     0    10    20    30    40    50    60    70    80    90   100   110
#>  [13]   120   130   140   150   160   170   180   190   200   210   220   230
#>  [25]   240   250   260   270   280   290   300   310   320   330   340   350
#>  [37]   360   370   380   390   400   410   420   430   440   450   460   470
#>  [49]   480   490   500   510   520   530   540   550   560   570   580   590
#>  [61]   600   610   620   630   640   650   660   670   680   690   700   710
#>  [73]   720   730   740   750   775   800   825   850   875   900   925   950
#>  [85]   975  1000  1025  1050  1075  1100  1125  1150  1175  1200  1225  1250
#>  [97]  1275  1300  1325  1350  1375  1400  1425  1450  1475  1500  1525  1550
#> [109]  1575  1600  1625  1650  1675  1700  1725  1750  1775  1800  1825  1850
#> [121]  1875  1900  1925  1950  1975  2000  2025  2050  2075  2100  2125  2150
#> [133]  2175  2200  2225  2250  2275  2300  2325  2350  2375  2400  2425  2450
#> [145]  2475  2500  2525  2550  2575  2600  2625  2650  2675  2700  2725  2750
#> [157]  2775  2800  2825  2850  2875  2900  2925  2950  2975  3000  3050  3100
#> [169]  3150  3200  3250  3300  3350  3400  3450  3500  3550  3600  3650  3700
#> [181]  3750  3800  3850  3900  3950  4000  4050  4100  4150  4200  4250  4300
#> [193]  4350  4400  4450  4500  4550  4600  4650  4700  4750  4800  4850  4900
#> [205]  4950  5000  5050  5100  5150  5200  5250  5300  5350  5400  5450  5500
#> [217]  5550  5600  5650  5700  5750  5800  5850  5900  5950  6000  6100  6200
#> [229]  6300  6400  6500  6600  6700  6800  6900  7000  7100  7200  7300  7400
#> [241]  7500  7600  7700  7800  7900  8000  8100  8200  8300  8400  8500  8600
#> [253]  8700  8800  8900  9000  9100  9200  9300  9400  9500  9600  9700  9800
#> [265]  9900 10000 10100 10200 10300 10400 10500 10600 10700 10800 10900 11000
#> [277] 11100 11200 11300 11400 11500 11600 11700 11800 11900 12000 12250 12500
#> [289] 12750 13000 13250 13500 13750 14000 14250 14500 14750 15000 15250 15500
#> [301] 15750 16000 16250 16500 16750 17000 17250 17500 17750 18000 18250 18500
#> [313] 18750 19000 19250 19500 19750 20000

accuracy = 3: High accuracy but low performance setting. Recommended for analysing individual profiles. Interpolation is performed with 5 m vertical resolution step up to 20 km AGL (i.e.: 0, 5, 10, ... 20000 m AGL)

Performance comparison:

library(thunder)
data("sounding_vienna")
t1 = system.time(sounding_compute(sounding_vienna$pressure, sounding_vienna$altitude, sounding_vienna$temp, sounding_vienna$dpt, sounding_vienna$wd, sounding_vienna$ws, accuracy = 1))
t2 = system.time(sounding_compute(sounding_vienna$pressure, sounding_vienna$altitude, sounding_vienna$temp, sounding_vienna$dpt, sounding_vienna$wd, sounding_vienna$ws, accuracy = 2))
t3 = system.time(sounding_compute(sounding_vienna$pressure, sounding_vienna$altitude, sounding_vienna$temp, sounding_vienna$dpt, sounding_vienna$wd, sounding_vienna$ws, accuracy = 3))
print(t1)
#>    user  system elapsed 
#>   0.002   0.000   0.002
print(t2)
#>    user  system elapsed 
#>   0.001   0.004   0.006
print(t3)
#>    user  system elapsed 
#>   0.111   0.000   0.111