Friday, May 6, 2011

May 9-11 Severe Weather Threat: Maximum Threat (Issued May 6)

With the severe weather threat about 3 days out, The Weather Centre has made initial theories about the potentially worst hit areas for the May 9-11 areas.
Below is the projected CAPEs and CINs.
Ignoring the blue dashed lines, look at the red shaded areas. Using the legend at the left, the GFS model is predicting CAPE values of possibly over 4000 j/kg.
This is a sudden increase in instability which suddenly decreases 6 hours later. That likely means that the predicted cold front has suddenly hit the unstable air mass.
That said, it can be expected the major severe weather should occur around 7pm CDT on May 10.
Below is the lifted index, which indicates more instability. The more negative, the more unstable.
The index will be at least -8, indicating very strong instability. This will also be very sudden. That said, the unstable air mass will be very strongly and quickly impacted by the storms.

The worst areas projected to be hit by severe thunderstorms are:
-East Oklahoma
-South Central Iowa
-Southeast Kansas
-North Missouri

Snapshot Forecast: May 6

Light showers with embedded storms will move east from the Ohio Valley and regroup in the 'entrance' to the Northeast.
There, these showers may become more of thunderstorms, and small hail isn't out of the question.
Scattered showers will also affect the Northwest into Montana.
Even West Texas may get in on isolated sprinkles.
Below are today's high temperatures.