The featured chart presents the highest forecasted surface based convective available potential energy (CAPE) from the GFS model for a grid point near Ames since the first of the year. This variable gives an indication to the degree of instability in the atmosphere that helps to facilitate thunderstorms. Values above 1,000 typically are when the stronger storms are possible. While values shown are well below 1,000 for surface based air parcels, CAPE computed for elevated parcels is expected to be larger and will allow for some hail producing storms in the coming week.

Voting:
Good = 12
Bad = 2

Tags:   cape  

The featured map displays the RUC computer weather model forecast of surface based CAPE for yesterday afternoon. CAPE is a measure of the vertical accelerations possible if air is forced upward initially. Typically, values of around 3,000 indicate severe storms are possible. Due to the extreme surface temperatures and dew points yesterday, values were over 10,000 J/Kg. Values this large are extremely rare.

Voting:
Good = 35
Bad = 10

Tags:   cape   model