** Instability Options **


** DEFINITIONS **

[CPR]  = Combined probability (Prob_Field_1 x Prob_Field_2 x ... x 
         Prob_Field_N)
[MAX]  = Maximum from any member at each grid point
[MD]   = Median
[MDXN] = Median value contoured.  The dashed red line is the union of 
         all members at the lowest contour value plotted (i.e., where 
	 at least one of the 16 members exceeds the value of the first 
	 median contour).  The dashed blue line is the intersection of
	 all members at the lowest contour value plotted (i.e., where 
	 all 16 members exceed the value value of the first median 
	 contour).
[MIN]  = Minimum from any member at each grid point
[MN]   = Mean
[MNSD] = Mean and Standard Deviation
[PM]   = Probability Matched Mean Value
[PR]   = Probability (percentage of members meeting/exceeding some 
         condition)
[SP]   = Spaghetti



** SPECIFIC INFORMATION ON AVAILABLE FIELDS **

[MDXN]:MLCAPE ->0 to 90 MB AGL parcel averaged CAPE.  Median MLCAPE
                (contours start at 500 J/kg) with union (dashed red) 
		and intersection (dashed blue) at 500 J/kg.
[MDXN]:MUCAPE ->As above but for the most unstable parcel (unmixed)
                surface to 500 mb AGL
[MDXN]:SFC_CAPE ->As above but for the surface parcel
[MNSD]:MLCAPE ->Mean and standard deviation of 0 to 90 MB AGL 
                parcel averaged CAPE
[MNSD]:MUCAPE ->As above but for the most unstable parcel (unmixed)
                surface to 500 mb AGL
[MNSD]:SFC_CAPE ->As above but for the surface based parcel
[PR]:700-500MB_LR>=_8.0 ->Probability 700 to 500 mb lapse rate
                          >= 8 degC
[PR]:DCAPE>=1000 ->Probability downdraft available potential 
                   energy is >= 1000 J/kg
[PR]:MLCAPE>=_1000 ->Probability MLCAPE (0-90 mb parcel ave) >=
                     1000 J/kg
[PR]:MLCAPE>=_2000 ->As above but for 2000 J/kg
[PR]:MLCAPE>=_3000 ->As above but for 2000 J/kg
[PR]:MLCAPE>=_500 ->As above but for 500 J/kg
[PR]:MUCAPE_to_500mb>=_1000 ->Probability most unstable CAPE (surface
                              to 500 mb AGL, unmixed parcel) >= 1000
			      J/kg
[PR]:MUCAPE_to_500mb>=_2000 ->As above but for 2000 J/kg
[PR]:MUCAPE_to_500mb>=_3000 ->As above but for 3000 J/kg
[PR]:MUCAPE_to_500mb>=_500 ->As above but for 500 J/kg
[PR]:SFC_CAPE>=1000 ->Probability surface based CAPE >= 1000 J/kg
[PR]:SFC_CAPE>=2000 ->Probability surface based CAPE >= 2000 J/kg
[PR]:SFC_CAPE>=3000 ->Probability surface based CAPE >= 3000 J/kg
[PR]:SFC_CAPE>=500 ->Probability surface based CAPE >= 500 J/kg


All SREF information presented herein is for guidance purposes 
only and should not be confused with official SPC operational 
forecasts.  Links to official SPC operational products are found 
at the bottom of every menu.

Many of the SREF products were developed for testing the utility 
of SREF analysis in the prediction of SPC mission critical items, 
including: thunderstorms and severe thunderstorms, large scale 
critical fire weather conditions, and mesoscale areas of hazardous 
winter weather. In order to accomplish this goal and test new and 
unqiue methods of SREF application in an operational environment, 
many fields not produced in the NCEP postprocessor were calculated 
locally for SPC purposes.



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