SKEW T VALUES
TP = Tropopause Height (mb) Height where the tropopause begins, or the temperature curve warms. The location of a tropopause height helps determine severe storm potential. If storm echo tops exceed tropopause height , severe weather is likely.

MW = Height of maximum wind level (mb)
FRZ = Lowest freezing level (mb) or BG if below ground

WB0 = Height of Wet Bulb zero (mb) or BG if below ground
	Potential for hail to reach the surface.

•	Strong- 7,000- 9,000 ft.

•	Moderate- 5,000 7,000 ft.   Or 9,000- 11,000 ft. 
•	Weak- below 5,000 , above 11,000 

PW = Precipitable Water (in)
	Measures the depth of liquid water at the surface that would result after precipitating all of the water vapor in a vertical column usually extending from the surface to 300 mb.

RH = Mean relative humidity (%) from the surface to 500 mb
MAXT = Est. maximum temperature (C) using a 150 mb layer
TH = 1000-500 mb thickness (m)

•	L57 = 700-500 mb lapse rate (C/km)
6.3 C/km Severe Tstorms 
•	7.0 C/km Tornadoes Possible     +7 indicates convective instability is present in the layer

LCL = Lifting condensation level (mb)

LI = Lifted Index (C) using 100 mean layer above surface
	A good measure of potential instability from the surface to 500mb. 

•	+0 Stable but convection possible 
•	0 to -3 C  Marginally Untable  
•	-3 to -6 C  Moderately Unstable  
•	-6 to -9 C  Very Unstable
•	> -9 C  Extremely Unstable 

 Limitations: LI uses a temperature difference between rising parcels and the environment at a single level and therefore cannot account for details in the environmental temperature curve above the LCL and below 500 mb.  

SI = Showalter Index (C)
	A measure of potential instability in the 850 mb to 500mb layer. 

•	+0 Stable but convection possible
•	0 to -3 Marginally Unstable
•	-3 to -6 Moderately Unstable
•	-6 to -9 Very Unstable
•	Greater (less than) -9 Extremely unstable

TT = Total Totals Index

TT = 45 to 50: 	Thunderstorms possible. 
	
TT = 50 to 55:
	Thunderstorms more likely, possibly severe. 
	
TT = 55 to 60:
	Severe thunderstorms most likely. 

KI = K Index

•	K below 30: Thunderstorms with heavy rain or severe weather possible (see note below). 
•	K  30-40: Better potential for thunderstorms with heavy rain. 
•	K =/+ 40: Best potential for thunderstorms with very heavy rain

SW = Sweat Index

•	SWEAT over 300: Potential for severe thunderstorms. 
•	SWEAT over 400: Potential for tornadoes.

EI = Energy Index 
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Parcel Derived Quantities (yellow line on soundings) 

CAPE = 

•	CAPE below 0: Stable. 
•	CAPE = 0 to 1000: Marginally unstable. 
•	CAPE = 1000 to 2500: Moderately unstable.
•	 CAPE = 2500 to 3500: Very unstable. 
•	CAPE above 3500-4000: Extremely unstable.

CINH = 
CIN represents the amount of negative buoyant energy available to inhibit or suppress upward vertical acceleration, or the amount of work the environment must do on the parcel to raise the parcel to its LFC. CIN basically is the opposite of CAPE, and represents the negative energy area (B-) on the sounding where the parcel temperature is cooler than that of the environment. The smaller (larger) the CIN is, the weaker (stronger) must be the amount of synoptic and especially mesoscale forced lift to bring the parcel to its LFC. High CIN values in the presence of little or no lift can cap or suppress convective development, despite possibly high CAPE values. Remember, CAPE is the "available potential" energy. That energy must be released to become "kinetic" energy to produce thunderstorms.

LCL = Lift condensation level (mb)
CAP = Cap strength (C)
LFC = 
EL = Equilibrium level (mb)- Height where the temperature of a buoyantly rising parcel of air again becomes equal to the temperature of the surrounding air. Usually, if the thunderstorm echo heights are above this equlibrium level it is referred to as Over Shooting Tops and is a precursor to severe weather.

MPL = Maximum parcel level (mb) 

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Wind Parameters 
STM = Estimated storm motion (kts) from 0-6000m AG mean layer, spd 75% of mean, direction 30 degrees veer from mean

HEL = Storm relative helicity 0-3000m AG (total value)

•	Hs-r = 150: The approximate threshold for supercell development. 
•	Hs-r = 150 to 299: Weak tornadoes (F0 and F1) possible. 
•	Hs-r = 300 to 449: Strong tornadoes (F2 and F3) possible. 
•	Hs-r over 450: Violent tornadoes (F4 and F5) possible.

SHR+ = Positive shear magnitude 0-3000m AG (sum of veering shear values)

EHI = Energy helicity index (proportional to positive helicity * CAPE) 

•	EHI below 1.0: Supercells and tornadoes unlikely in most cases, but be aware of convective interactions and shear zones that could make EHI values unrepresentative. 
•	EHI = 1.0 to 2.0: Supercells and tornadoes are possible but usually tornadoes are not of violent or long-lived. Can get non-supercell/shear vorticy tornadoes near the leading edge of bow echoes/LEWPS. 
•	EHI = 2.0 to 2.4: Supercells more likely and mesocyclone-induced tornadoes possible. 
•	EHI = 2.5 to 2.9: Mesocyclone-induced supercellular tornadoes more likely. 
•	EHI = 3.0 to 3.9: Strong mesocyclone-induced tornadoes (F2 and F3) possible. 
•	EHI over 4.0: Violent mesocyclone-induced tornadoes (F4 and F5) possible.

BRN = Bulk Richardson number 500-6000m AG (proportional to CAPE/ bulk shear
BRN below 10: 	Strong vertical wind shear and weak CAPE. The shear may be too strong given the weak buoyancy to develop sustained convective updrafts. However, given sufficient forcing, thunderstorms may still develop; if so, rotating supercells could evolve given the high shear.
	
BRN = 10 to 45: 
	Associated with supercell development.
	
BRN over 50: 
	Relatively weak vertical wind shear and high CAPE which suggests multicellular thunderstorm development is most likely

BSHR = Bulk shear value (magnitude of shear over layer) BRN Shear is defined as the magnitude of 0 - 6 km horizontal wind difference

•	25 - 100 ms-1  Tornadic Supercells possible