Thursday, April 30, 2009

Severe Potential Friday & Saturday

A lot of people have asked about the threat for severe thunderstorms on both Friday and Saturday.

FRIDAY
Let's first tackle Friday's forecast. The front will reside out west, so we will see a strong SW wind which will bring heat and humidity back to the area.


This will make the atmosphere slightly unstable.


Jet stream winds will be strong enough to provide some speed shear (winds increasing with height). In addition, with surface winds from the southwest and jet stream winds from the west, there is some directional shear (twist) in the atmosphere.


With the front so far away on Friday, thunderstorms will remain very isolated, so we are not expecting widespread severe weather.

SATURDAY
The front will settle into the area on Saturday.


The atmosphere will also become unstable.


Just like on Friday, jet stream winds will be moderately strong from the west, so we will have both speed and directional shear.


Taking this all into account, the threat for severe storms looks higher for Saturday. The key to the forecast is sunshine. If we are stuck in thick cloud cover, then the severe potential will drop.

It's something we are watching very closely and will have more updates to come!