** Winds and Shear 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]:0-1KM_SRHelicity ->Median 0 to 1 KM storm relative helicity
                          (contours start at 100 m^2/s^2) with union 
			  (dashed red) and intersection (dashed blue) 
			  at storm relative helicity of 100 m^2/s^2.
[MDXN]:0-3KM_SRHelicity ->As above but for 0 to 3 KM storm relative
                          helicity.  Contouring begins at 150 
			  m^2/s^2.
[MDXN]:Effective_Shear ->Median of the effective shear (first contour
                         is 30 kts) with union (dashed red) and 
			 intersection (dashed blue) at 30 kts. Effective
			 shear is defined here as the shear in the lower 
			 50% of the convective cloud between LPL and EL.			
[MNSD]:0-1KM_SRHelicity ->Mean and standard deviation of 0 to 1 KM 
                          storm relative helicity
[MNSD]:0-3KM_SRHelicity ->Mean and standard deviation of 0 to 3 KM 
                          storm relative helicity
[MNSD]:Effective_Shear ->Mean and standard deviation of effective
                         shear (kts).  Effective shear is defined here 
			 as the shear in the lower 50% of the convective 
			 cloud between LPL and EL.
[PR]:0-1KM_SRHelicity>=100 ->Probability 0 to 1 KM storm relative helicity
                             >= 100 m^2/s^2
[PR]:0-1KM_SRHelicity>=150 ->Probability 0 to 1 KM storm relative helicity
                             >= 150 m^2/s^2
[PR]:0-3KM_SRHelicity>=100 ->Probability 0 to 3 KM storm relative helicity
                             >= 100 m^2/s^2
[PR]:0-3KM_SRHelicity>=300 ->Probability 0 to 3 KM storm relative helicity
                             >= 300 m^2/s^2
[PR]:Effective_Shear>=30kts ->Probabilty effective shear >= 30 kts.
                              Effective shear is defined here as the 
			      shear in the lower 50% of the convective 
			      cloud between LPL and EL.
[PR]:Effective_Shear>=40kts ->As above but for 40 kts
[PR]:Effective_Shear>=50kts ->As above but for 40 kts


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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