Severe Severe Weather February 16th -18 2022

[Zander98al]

Peek the cloud cover forecasts from the nam and GFS at the same timeframe almost near midnight before the main action. More cloud breaks will aid in higher lapse rates and instability if these cloud breaks maintain. Already near 6.5+ in projections. Models are probably about to go stupid with potential I'f nam trend is right. SOOO buckle up just in case. No guarantee but we're about to be sampled in a day or two and be in the NAM range.

 

[Zander98al]

Look at the trough at the same timeframe between both models as above. NAM bottom; is still digging some and is still in the downward dive. The GFS is neutral and ready to eject. So the nam is probably indicating to a bit more of a southeastern push of the tro

 

[Zander98al]

18z nam vs 12 GFS. Nam has this more considlated and digging more as it's ejecting of getting ready to eject. Also threw in a euro pic as well lol

 

[Zander98al]

@Myfrotho704_ is the difference in the strength of the troughs by the globals and the nam mean anything?

 

[TileDude]

 

[TileDude]

From Bham NWS afternoon discussion:


LONG TERM...
/Updated at 0238 PM CST Sun Feb 13 2022/

The overall battle of the models continue. While the main
forecast timing, albeit a touch slower, is still very close
with the system sliding through Midday and into the area,
instabilities values are higher this afternoon. Would expect this
to continue until we can get more of the higher resolution. The
overall synoptic pattern still showers a pretty good chance at
seeing severe weather across the the Southeast on Thursday. Trying
to get into the fine details is really too much at this time.
Bottom line is that we will see strong storms and moderate to
heavy rain. Severe storms will be possible especially with the
system sliding through during the afternoon.

 

[Zander98al]

From Bham NWS afternoon discussion:


LONG TERM...
/Updated at 0238 PM CST Sun Feb 13 2022/

The overall battle of the models continue. While the main
forecast timing, albeit a touch slower, is still very close
with the system sliding through Midday and into the area,
instabilities values are higher this afternoon. Would expect this
to continue until we can get more of the higher resolution. The
overall synoptic pattern still showers a pretty good chance at
seeing severe weather across the the Southeast on Thursday. Trying
to get into the fine details is really too much at this time.
Bottom line is that we will see strong storms and moderate to
heavy rain. Severe storms will be possible especially with the
system sliding through during the afternoon.

I think on my posts above the nam is more volatile for our area. The upper level low may not shear out or as fast as the globals which leads to better height falls for the twin states. I've said many times I think this event has a high ceiling. The instability levels like they say that are higher today will continue to rise more and likely. I see the most likely threshold to be 2000j or so. Which is pretty good for a winter setup. You usually only see central Alabama and Mississippi reaching a max of 2500j in the winter time any any given setup.

But the daytime passage of storms is a biggie for winter events when you need the most help you can get with instability

 

[Zander98al]

 

[Darklordsuperstorm]

 

[Zander98al]

Sounding on the Mississippi Alabama state line. The LCL is basically almost scraping the ground with how low it is ?. I tell you when the Thermodynamics catch up. This is going to be a nasty setup. Still questions marks. BUT daytime arrival will alleviate some question marks if true.

 

[Darklordsuperstorm]

I picked a heck of time to take a beach trip for the weekend leaving early Thursday morning. Hopefully this means atleast the weather for a little while on Thursday will be nice and warm ahead of the storms. If nothing else I'll be able to report on what kind of airmass is blasting northward from the GOM.

 

[Arcc]

Sounding on the Mississippi Alabama state line. The LCL is basically almost scraping the ground with how low it is ?. I tell you when the Thermodynamics catch up. This is going to be a nasty setup. Still questions marks. BUT daytime arrival will alleviate some question marks if true. View attachment 113526

Just no way to get around that warm layer though and with the monster moisture advection you are gonna have cloud cover.

 

[Myfrotho704_]

Just no way to get around that warm layer though and with the monster moisture advection you are gonna have cloud cover.

Yep, lapse rates are pretty meager still and the sounding just looks like grunge, looks like a Stratiform/elevated convection fest

 

[Arcc]

Yep, lapse rates are pretty meager still and the sounding just looks like grunge, looks like a Stratiform/elevated convection fest

This look alone makes me almost 100% sure most of AL will be socked in with clouds/showers, if not just rain. In this setup, you absolutely must have sunshine to get prefrontal convection and that likely still wont be enough.

 

[accu35]

How bad is this for south Alabama?

 

[Zander98al]

This look alone makes me almost 100% sure most of AL will be socked in with clouds/showers, if not just rain. In this setup, you absolutely must have sunshine to get prefrontal convection and that likely still wont be enough.

Why would the nws bham be confident in tornadoes then? Cips analogs is also confident in a decent threat.

 

[Myfrotho704_]

This look alone makes me almost 100% sure most of AL will be socked in with clouds/showers, if not just rain. In this setup, you absolutely must have sunshine to get prefrontal convection and that still may not be enough.

Yep, fully saturated tropospheric soundings/poor tropospheric lapse rates and already present stratiform/elevated convection gives this setup a big reason to not be a big deal for AL/eastern miss. Also typically we shift the pseudo warm front south at go time vs modeled a few days before. Lots going against this setup, only area I could see being more interesting is the very southern sections

 

[Arcc]

Why would the nws bham be confident in tornadoes then? Cips analogs is also confident in a decent threat.

Definitely a chance of tornadoes with the front, but for a big pre-frontal threat, this isn't it. You can be confident in severe weather, but also be confident that unless something major changes it wont be a high end threat.

 

[Arcc]

Yep, fully saturated tropospheric soundings/poor tropospheric lapse rates and already present stratiform/elevated convection gives this setup a big reason to not be a big deal for AL/eastern miss. Also typically we shift the pseudo warm front south at go time vs modeled a few days before. Lots going against this setup, only area I could see being more interesting is the very southern sections

Yep, the gulf coast areas is normally the place to watch in these low laspe rate/high shear events. Those wind field shear/profiles are nasty.

 

[Scott81]

It's still early in the game. Things can still change, and probably will.