Pre storm analysis with Derived Products and METOPS sounding

The Grand Forks CWA was recovering from a previous line of showers.  The sun was returning and heating the environment.

Temps were recovering into the mid 80s with DPs in the low to mid 60sby 20z.
Metars showed a wind shift line SW/NW right on the border of our CWA.

Derived Cape at 1902z ran from 450-500 in our northwest counties to 175-200 in the southwest. There was a gradient that lined up with the wind shift line (west of wind shift line dropped  to zero).  Animation showed the gradient moving with the wind shift.

Derived TPW ran in the 1.2-1.3" range on the average.  Animation showed a gradient moving from west to east with the highest values along the wind shift, dropping to 0.6" behind  the wind shift. 

Conclusions of Derived Cape and TPW:

It was fascinating to see the satellite derived CAPE and TPW oriented to the wind shift line as it moved from west to east (whether the numbers are exact or not, the relative orientation was there).  We expect initiation along that line.

We also picked a METOPS-A sounding in the far southwest part of the CWA where instability looked the highest.

The original METOPS-A sounding was from 1647z, and we were now at 20z.  CAPE was zero, not very unstable.
The original is below:

Modifying it to 20z ob T=84F and C=63 we got SB CAPE 1443.  I used the method I learned yesterday of following mixing ratio to modify DP up from surface.  Also modified T a little bit above the surface to look more like reality.
Edited METOPS-A Sounding below:

Conclusion of METOPS-A:

Modifying the sounding was necessary since 2 hours had elapsed from 1706-1902 and heat and moisture had jumped considerably.

Davis Nolan
WKRN Meteorologist

Our environment is not overly unstable.