Okay then let's get into this... A large trough continues to dominate the western U.S. with a ridge across the east. Two strong disturbances will eject out of the trough and track to the east, northeast. The main dynamics with the first feature will stay well west - northwest of us. There is a slight risk for severe storms under the upper H5 system across the central Plains today including large hail, gusty winds, and even some tornadic activity if convection can become rooted in the boundary layer.
The trailing energy from this system will come close enough to us to bring us shower activity later tonight into tomorrow (Tuesday) morning with mild and mainly dry weather returning Tuesday afternoon.
Quiet conditions will prevail Tuesday evening but after midnight, showers and thunderstorms (mainly elevated) should rapidly develop and spread northeast across the Ohio Valley as the next strong H5 short ejects from the western trough. This H5 wave will enhance the LLJ which will increase from 60 to 75 kts. The strengthening low level convergence on the nose of the LLJ will result in strong vertical motion - showers and thunderstorms.
This batch of showers and storms will moves east, northeast quickly Wednesday morning. Then the next wave of showers and perhaps some thunderstorms will arrive with the main H5 short energy and its associated cold front.
As the system approaches, the wind field will increase dramatically across the Ohio Valley with 0 to 6 k shear values anywhere from 50 to 80 kts from the Ohio Valley and points south.
The prefrontal trough is expected to move through the regio between 18z and 21z Wednesday. This is where our best chance for severe weather will come from IF it happens at all.
As I said before, dynamics... great !! Lift... awesome !! What may be lacking is instability. Check out the latest NAM instability charts... Not much there !
Having said that and at this time, I still think there's a chance we could see a fast moving narrow line of low topped convection do in part to the very strong low level forcing. This may be one of those situtations where there is little or no lightning but the just a narrow zone of very heavy showers embedded within a larger zone of more general rain. As this low topped convection moves through, it still looks to me that there will be the potential for strong straight lined winds and some wind damage - like we need more of that after Ike and then the ice storm. I don't see much of a threat at tornadic weather right now as most if not all the low topped convection will occur along the prefrontal trough in more of a squall line configuration. Of course, if instability were to increase... well that would be a different story as the convective mode would also be different and likely include some discrete cells ahead of the main forcing giving rise to tornadic activity. Again though, at this time I don't see that happening with the instablity now progged by the latest guidance. As always, we'll watch it close for any changes.
Weather History:
1990 - Thunderstorms developing ahead of a cold front erupted over eastern Texas late in the morning, and produced severe weather as they swept across the southeastern states. Early evening thunderstorms spawned a tornado which injured one person at Nat TX, and produced tennis balls size hail which caused more than half a million dollars damage around Shreveport LA. (The National Weather Summary) (Storm Data)
Have a great day all,
Jay
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