Forecast CAPE (Convective Available Potential Energy is beginning to ramp up over the Delta. Higher CAPE will allow the Thunderstorm updraft to strengthen and cloud tops to achieve much higher altitudes. With the moisture in place right now, don't be surprised to have a few storms race across with high precipitation rates. The storms tomorrow night are going to move really fast, with the potential for some high winds. Tornado threat for the Delta seems moderate at best. The northerly position of the Warm Front puts the Delta under southerly flow. Low-level turning of the winds is very important for tornado formation, something the Delta environment won't have tomorrow. (Unless something really surprising happens) If a Mesoscale boundary can establish itself before the main convection begins, we could see a heightened Tornado risk, but I highly doubt that will happen. A boundary can ramp up Tornado risk by turning the low level winds, effectively increasing Bulk Shear. I'll post the Jackson, MS and Little Rock, AR Soundings and Hodographs in the morning and briefly discuss them before the event starts to unfold.
800 Joules/Kg CAPE in February is considered strong.
The Shear Environment is still forecast to be strongest North of the Delta, but that doesn't exempt us from some straight line winds.
EHI is a parameter consisting of Shear and CAPE. A forecaster looks at EHI to determine the best Instability/Shear combination. Interestingly enough, there is an EHI bull's-eye over the MS Delta.
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