To All;

Today is lining up to produce some of the wildest wx that we’ve seen in quite some time.  With frontal passage this morning, the Satellite Imagery shows a large section of the SJV is now under mostly clear skies.  A secondary band of convective-type showers and Thunderstorms is already organizing along the Coast Range and will be cross the Valley in a few hours.  The atmospheric parameters being set-up this morning are classic SEVERE for the SJV. This is not to say that every spot in the valley will receive a Severe Thunderstorm, but there is a high probability that there will be a few of them around later this afternoon.   Strong SE winds at the surface combined with directional wind shear aloft has the potential to produce rotating Supercell Thunderstorms which may produce any of the following;  heavy downpours of rain, small hail, large hail, gusty downdraft gust-front type winds, frequent lightning, possible funnel clouds and/or small tornadoes.   Hail size could range up to 0.5 to 1 inch in cells which have the strongest updrafts.  The longer the clear skies presently over the SJV allow for diurnal heating to occur, the greater the chances of SEVERE Thunderstorms this afternoon.   If you have access to a camera and see a thunderstorm in progress, please record it for prosperity and share it with us.


In a rare move, the Storm Prediction Center has issued a 2% probability of Tornado for the Great Valley region. 



SPC Hail Outlook; showing 5% chances of 1 inch diameter hail or larger within a 25 mile point.



Current 9am Supercell Parameter chart Friday morning already showing a +2 value over the SJV