** 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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