Severe WX March 23-25th, 2023

[UncleJuJu98]

It would be fitting if this was the setup that produced something higher end (like 1/12, or perhaps even beyond that) given the model inconsistency that has plagued it from longer range. Seems like we've had numerous setups already this year that had much better consistency and agreement from further out, only for them to still fall apart or at least diminish considerably in ceiling inside of Day 4.

Lol very good point haha the more unsuspecting the event the higher it produces like 1/12 . Both of our higher end forecasted and hyped events busted majorly.

 

[UncleJuJu98]

From Birmingham NWS morning discussion:

From a synoptic perspective, there are several bullish factors
pointing toward a potentially significant severe weather event
across the MS/AL region. In fact, the shape of the 500mb trough on
the global models is classic and suggestive of a tornado outbreak
across the Deep South. Of course there are other ingredients that
need to fall into place for that potential to be realized, but we
are seeing trends in that direction. Moisture quality and
instability has improved when looking at the trend of 850-925 mb
dewpoints, but models are very likely not handling the lowest part
of the boundary layer correctly during the overnight hours.
Temperatures on Friday will reach the 80s across the region, and
there is no good reason why temperatures should fall into the mid
to upper 60s during the evening in the midst of southerly winds
and an increasing low-level jet, as shown by some models.
Correcting for this bias suggests that temperatures will be in the
70-73F range as dewpoints increase into the mid to upper 60s.
This should yield more instability than currently depicted by the
GFS and ECMWF. Additionally, cold advection at 500mb is being
indicated, and the leading edge of this appears to be paired with
the expected corridor of severe storms. This should help maintain
or enhance mid-level lapse rates through the event, while
tempering the effects of latent heat release and not allowing the
atmosphere to turn over.

That's pretty concerning wording from bham lol...

 

[MichelleH]

That's pretty concerning wording from bham lol... View attachment 18871

Our own Matt Grantham wrote this morning's AFD.

 

[JBishopwx]

NWS Jackson, who usually follows the SPC lead, has a risk area out for Sunday also.

 

[UncleJuJu98]

As we are gearing up for a potential tornado/ severe event I'd like to note to everybody it'll be on a Friday evening into early Saturday so work shouldn't be a issue for Mississippi and Alabama folks. Which makes me happy. I'll be doing my best impersonation of a armchair meteorlgist on radarscope hahah

 

[warneagle]

This is a very unscientific observation but it's one I've made over many years of amateur armchair forecasting. On the forecast soundings for Friday cherry-picked from the areas of highest EHI, I'm consistently seeing at least one, often more "sig" analogs in the SARS list (Birmingham at 18Z 12/16/00 - 2000 Tuscaloosa F4 - seems to be a common one).

A lot of times I've seen events where the forecast soundings in the days leading up to it have impressive numbers for the parameters and may even trip the "PDS TOR" tag, but if they don't have any analog matches or only "weak" ones, it's a red flag that there's something subtly "off" about the environment and the event is likely to bust or underperform.

This is something I look for as well and I've noticed the same trend. I think it's just my natural instinct as a historian to look for historical parallels, so I pay a lot of attention to the analogs, and my interpretation at least is that if there are strong analogs then it's more likely that the environment that the models are depicting is a realistic severe weather scenario rather than some artifact of the model or something like that.

 

[UncleJuJu98]

 

[Taylor Campbell]

That's two days old and was overblown by the 4/27/11 analog.

 

[Argus]

A friend of mine is going to start his funnel cake business on Saturday and his daughter's going to a military ball that evening. Looks like it might mess up their plans.

 

[UncleJuJu98]

That's two days old and was overblown by the 4/27/11 analog.

Not necessarily overblown, just look at current cips is identical the threat area on cips will move around. It still takes into account the top 15 analogs not just one overblown one. Albeit I'm not banking on a widespread outbreak lol

 

[JPWX]

FYI the last Moderate Risk for Mississippi into Alabama in March was March 30th, 2022.

 

[JBishopwx]

 

[UncleJuJu98]

View attachment 18873
View attachment 18874

View attachment 18876

Seems like the MMFS and CSU severe probability forecasting model are zoning in around the Delta and points west for a enchanced significant corridor.

 

[CheeselandSkies]

I really hope Little Rock, Jackson, Shreveport, Ft. Polk and New Orleans radars are all functioning come Friday afternoon/evening.

 

[UncleJuJu98]

12z nam is incredibly cellular.

850mb vertical vort and simulated radar indicate supercellular.

 

[UncleJuJu98]

Instability is very high for a overnight / morning event in Alabama. Although I'm curious... As to whether the best shear and instability will mesh dynamics maybe lifting off before the best instability I'm the morning.

This isn't looking good folks. The wacky stage of the NAM is starting to wear off I'm afraid getting into a more solid range.

 

[CheeselandSkies]

Interesting that the first sniff of the 3K NAM out to 00Z Saturday is rather muted with the EHI as well as the simulated reflectivity/updraft helicity, but that seems to be somewhat common with that model. For some reason it doesn't really mirror the regular NAM to the extent you'd think it would, at least at the end of its range.

I wonder if it maybe has a later deepening of the surface low and hence the low level jet response and consequent enlarging of the hodographs takes place after the end of the run. Because the regular NAM looks extremely dangerous especially across northeastern Arkansas/the MO bootheel at 0Z Saturday. But, the hodographs are large and strongly curved across most of AR/LA.

 

[UncleJuJu98]

Interesting that the first sniff of the 3K NAM out to 00Z Saturday is rather muted with the EHI as well as the simulated reflectivity/updraft helicity, but that seems to be somewhat common with that model. For some reason it doesn't really mirror the regular NAM to the extent you'd think it would, at least at the end of its range.

I wonder if it maybe has a later deepening of the surface low and hence the low level jet response and consequent enlarging of the hodographs takes place after the end of the run. Because the regular NAM looks extremely dangerous especially across northeastern Arkansas/the MO bootheel at 0Z Saturday. But, the hodographs are large and strongly curved across most of AR/LA.

Definetly I've quit looking at the 3km nam at this point and just wait for the long range RAP and WRF runs lol

 

[Scott81]

Buckle up! It could be a wild ride!

 

[WesL]

Buckle up! It could be a wild ride!