chrisbray
EF4
I am aware of the broader and more significant threat in the TX/OK/ARK area, but I will selfishly stick to MO/IL/IN/KY as this is my target area. I will let others handle the rest.
Yesterday morning I noticed the NAM starting to suggest a decent sized unstable airmass advecting up towards central IL/IN, much farther than tho Ohio River Valley models has previously been limiting it to. While the main trough and shortwave well be well to the west, there is still sufficient flow overspreading the region to introduce a conditional threat to the area - this has been noticed by the SPC as well, introducing a marginal risk overnight and suggesting in their recent day2 outlook there is a categorical upgrade more model consensus is reached. The warm sector is progged to have great moisture quality a depth - Euro/NAM show upper 60s dews and the moist layer extending through the 850mb layer - and instability of around 2k MLCAPE for the most part. Shear is there as well, with models showing generally 45 knots bulk shear 0-6.
There are to main concerns for me -
1: how far north does the front actually get? In my experience, these subtle warm front setups often get hung up much farther south than forecast models believe leading up to the event. This is often due to convective reinforcement which global models have issues resolving, but CAMs can show. Indeed I already see hints of this happening with widespread overnight convection on the HRRR. Of course, this we won't know until the morning of. If it's apparent that the front doesn't get much past I-64, then I can't justify a few hours of driving to chase amongst the forests of southern Illinois. If it's closer to I-70, that area is surprisingly doable.
2: Is there actual forcing for storms? The presence of the warm front is always welcome for enhancing shear/vorticity in the area, and there is indeed upper level flow all across the area. But so far there is no real consensus on timing of subtle waves or impulses during peak heating that would be enough to initiate. I'm very welcome to help finding them here, as I feel this is one of the harder areas for me master. It seems like there might be small perturbations in the 500mb flow crossing the area tomorrow with slight height changes, but not really sure how much of it is real and how much is just convective influence on the models. On the other hand, the 18z just came out with an MCV from overnight convection tracking right along I-70, which would be the ideal scenario for me!
TLDR - assuming the warm sector makes it somewhat near I-70 and isn't wiped by overnight convection, and there are signs of initiations from CAMS in the morning, it will likely be enough to get me out the door since I am confined to local chases only this season, and given the weak long range signals for May, it may be one of the few opportunities for a while
Yesterday morning I noticed the NAM starting to suggest a decent sized unstable airmass advecting up towards central IL/IN, much farther than tho Ohio River Valley models has previously been limiting it to. While the main trough and shortwave well be well to the west, there is still sufficient flow overspreading the region to introduce a conditional threat to the area - this has been noticed by the SPC as well, introducing a marginal risk overnight and suggesting in their recent day2 outlook there is a categorical upgrade more model consensus is reached. The warm sector is progged to have great moisture quality a depth - Euro/NAM show upper 60s dews and the moist layer extending through the 850mb layer - and instability of around 2k MLCAPE for the most part. Shear is there as well, with models showing generally 45 knots bulk shear 0-6.
There are to main concerns for me -
1: how far north does the front actually get? In my experience, these subtle warm front setups often get hung up much farther south than forecast models believe leading up to the event. This is often due to convective reinforcement which global models have issues resolving, but CAMs can show. Indeed I already see hints of this happening with widespread overnight convection on the HRRR. Of course, this we won't know until the morning of. If it's apparent that the front doesn't get much past I-64, then I can't justify a few hours of driving to chase amongst the forests of southern Illinois. If it's closer to I-70, that area is surprisingly doable.
2: Is there actual forcing for storms? The presence of the warm front is always welcome for enhancing shear/vorticity in the area, and there is indeed upper level flow all across the area. But so far there is no real consensus on timing of subtle waves or impulses during peak heating that would be enough to initiate. I'm very welcome to help finding them here, as I feel this is one of the harder areas for me master. It seems like there might be small perturbations in the 500mb flow crossing the area tomorrow with slight height changes, but not really sure how much of it is real and how much is just convective influence on the models. On the other hand, the 18z just came out with an MCV from overnight convection tracking right along I-70, which would be the ideal scenario for me!
TLDR - assuming the warm sector makes it somewhat near I-70 and isn't wiped by overnight convection, and there are signs of initiations from CAMS in the morning, it will likely be enough to get me out the door since I am confined to local chases only this season, and given the weak long range signals for May, it may be one of the few opportunities for a while
