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Severe Weather 4/17/26

As of now I really only see the NAM showing that entirely screwing up the threat. GFS+GEFS Ensembles are still holding strong on OK and KS getting a pretty potent threat.
The trend on the GFS and GEFS is not encouraging. Cold front has been coming further south each run and we still have two days for it to crash further south.
 
Honestly not sure what’s all the hype with Friday. Looks like qlcs slop to me.
Sure the kinematics are upper echelon but when dealing with a cold front, shear vectors go out the window. You’re guaranteed to have immediate upscale growth into a squall line regardless of how favorable the jet streak orientation relative to the PBL winds are.
Not saying it won’t be bad obviously since qlcs events can produce sig tornado outbreaks.
But unless prefrontals form then the violent tornado potential will be less than it was yesterday.
 
Honestly not sure what’s all the hype with Saturday. Looks like qlcs slop to me.
Sure the kinematics are upper echelon but when dealing with a cold front, shear vectors go out the window. You’re guaranteed to have immediate upscale growth into a squall line regardless of how favorable the jet streak orientation relative to the PBL winds are.
Not saying it won’t be bad obviously since qlcs events can produce sig tornado outbreaks.
But unless prefrontals form then the violent tornado potential will be less than it was yesterday.
Friday or Saturday?
 
We may not have had a truly high-end event yet, but the sheer number of events has still been pretty impressive. I keep thinking back to 2024, where our first big event wasn't even until 04/27.
That pattern flip was dramatic. Most likely brought on, as you noted before, by TNI changes.

The one big flag I have for May is the drought. Will the EML be so extremely stubborn that we can’t have CI in the plains region for events?
 
Friday. My bad, always get tricked because tropical tidbits has the days go by once the slider hits 7pm.

They all should, since the weather enterprise generally operates on UTC/Zulu time, and 00Z (midnight) is 7 PM CDT the previous evening.
 
There is outbreak potential up north in the Midwest (MN/IA/WI/IL) based on what I'm seeing come off the latest guidance. Not exactly sure what people are looking at, but it is not the front that is the concern up there. It will be one or more pre-frontal confluence bands initiating supercells into a very impressive parameter space (assuming morning convection is rather minimal).
 
The hrrr is now in range for this Friday so not like it means much but it does indeed show prefrontal development out ahead of the coldfront.
Again though, two days out and I would like to see most or all cams show a similar solution so this by itself is pretty meaningless.

The NAM 3 km also has pre-frontal development (and rather robust, I might add), but kills it in an environment where it shouldn't as per usual.
 
The NAM 3 km also has pre-frontal development (and rather robust, I might add), but kills it in an environment where it shouldn't as per usual.
Yea, for whatever reason the high res NAM has a major inversion layer bias.
But even with that, just looking at 500mb potential vorticity you can tell the forcing in this region will be far from nebulous and by most accounts should support prefrontal convection.
 
Honestly more impressed up north in IA/MN/IL/WI (again, can these guys catch a break?) than the southern plains. Appears more favorable for supercellular development and forcing appears sufficient for prefrontals. If morning convection doesn't wash out the parameter space which I don't see as of now, we have potential for multiple strong tornadoes with any supercell that can mature. Dare I say potential for an outbreak.
 
If any of you doubt me, all you need to do is go look at the ridiculous EML/700-500 mb lapse rates advecting into the Midwest early Friday afternoon on just about every piece of available guidance. That is a major red flag.
 
Honestly more impressed up north in IA/MN/IL/WI (again, can these guys catch a break?) than the southern plains. Appears more favorable for supercellular development and forcing appears sufficient for prefrontals. If morning convection doesn't wash out the parameter space which I don't see as of now, we have potential for multiple strong tornadoes with any supercell that can mature. Dare I say potential for an outbreak.
Shocker lol.. up north
 
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