March 14-16 2025 Severe Threat

[WxSynopsisDavid]

1 hour ago, JasonOH said:

I’ll leave the 06z HRRR run here for posterity. I think the true analogue for how this will end up is 3/21/1932. Not sure what I would put the floor at, but it’s really high in my opinion. If instability is underdone like usual, I think we are in a world of hurt with the synoptic environment being as good as it is. Barring a morning MCS, which seems unlikely at this time, I think this one is a lock for a really bad day.

To me, it’s a tick away from being a Super Outbreak. Moisture uncertainties are for me the biggest uncertainty. However, another uncertainty for me is just how this open warm sector will evolve tomorrow. In recent years we have seen these open warm sectors/loaded gun environments fail because of morning convection. Important to note, 4/27/11 had morning convection but it did nothing to temper the environment. It’s also not a great sign that the closer we get to tomorrow, the more nastier the model guidance is getting.

[ATDoel]

15 hours ago, WxSynopsisDavid said:

To key off your remarks, whenever the data presents it self in the future, we will know for certain when an outbreak is going to go Super Outbreak. They have a classic, textbook anomalous appearance with every facet of model data we use to measure the environment. At this range, there’s typically no limiting factors. With this weekends outbreak, there are a ton of fail modes possible. Not to mention quite a few scenarios involving timing issues. Moisture return is one of the greater uncertainties right now.

I can't say I agree with you here considering that before our last Super Outbreak, 4/27/2011, we weren't aware it was going to be a super outbreak just the day before it occurred.  Storm Prediction Center Apr 26, 2011 0600 UTC Day 2 Convective Outlook we didn't even get a 45% tornado risk area until the middle of the day on 4/27/2011.

To play devil's advocate here, what do you think happens tomorrow if none of those failure modes materialize?  While I think it would be irresponsible to call for a super outbreak on any given event this far out, I feel like it's also irresponsible to suggest that we have the ability to be absolutely certain when an event will or won't be a super outbreak a this stage of the forecast..

[GoAPPS]

[kayman]

I'm going to go out on a limb but the SPC forecast for Sunday will yield an Enhanced risk area from a north to south area from Suffolk, VA to Sumter, SC.

[WxSynopsisDavid]

56 minutes ago, ATDoel said:

I can't say I agree with you here considering that before our last Super Outbreak, 4/27/2011, we weren't aware it was going to be a super outbreak just the day before it occurred.  Storm Prediction Center Apr 26, 2011 0600 UTC Day 2 Convective Outlook we didn't even get a 45% tornado risk area until the middle of the day on 4/27/2011.

To play devil's advocate here, what do you think happens tomorrow if none of those failure modes materialize?  While I think it would be irresponsible to call for a super outbreak on any given event this far out, I feel like it's also irresponsible to suggest that we have the ability to be absolutely certain when an event will or won't be a super outbreak a this stage of the forecast..

Disagree, because there were a few of us that knew 1 day out that 4/27/11 was going to be the next Super Outbreak. Evidence of that can even be found here if you go back far enough in the threads. The fail modes we have with this weekends event and the moisture issues we have seen on the models, we didn’t have 1 day out for 4/27/11. Most of us were discussing what impact that morning MCS was going to have: would it cap the outbreak to a Regional Tornado Outbreak or create a Conus-Wide Super Outbreak? There are certain anomalous signals that when they present themselves you know if the outbreak is going to become a Super Outbreak. Research 4/3/74 and 4/27/11. And for clarification, the day before 4/27/11, I did not imagine the event producing 200+ tornadoes in that 24hr period. My expectation was total count to be similar to 4/3/74.

[gtg947h]

22 minutes ago, WxSynopsisDavid said:

far enough in the threads

Just dug around to find such a thread, if anyone's curious...

 

I have a lot of family right near FFC, watching this weekend's one closely...

[olafminesaw]

Today's SPC discussion mentions gusts of 60-100mph. Can anyone think of a time when the SPC mentioned wind gusts that high, excluding Derecho setups?

[GaWx]

24 minutes ago, olafminesaw said:

Today's SPC discussion mentions gusts of 60-100mph. Can anyone think of a time when the SPC mentioned wind gusts that high, excluding Derecho setups?

For what area and when is the SPC mentioning 60-100 mph gusts?

[Brick Tamland]

Don't think much will happen here in central NC if we don't get some sun in the morning. We usually need some sun to provide the spark for severe storms here. Today has been a lot cooler than forecasted, too 

[olafminesaw]

14 minutes ago, GaWx said:

For what area and when is the SPC mentioning 60-100 mph gusts?

Day 1 for the Midwest in the discussion. Probably better question for the Lakes/Ohio valley subforum, kinda forgot this was the SE thread!

[yoda]

Uh oh

 

[olafminesaw]

[ATDoel]

Day 2 high risk, when has that ever happened before?

[olafminesaw]

They actually reduced the wind threat, removing the 45% area entirely. I guess that may be due to increased confidence in super cell storm mode, which don't tend to produce a wide swath of high straight line winds 

[yoda]

1 minute ago, ATDoel said:

Day 2 high risk, when has that ever happened before?

3rd time ever

[yoda]

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1230 PM CDT Fri Mar 14 2025

   Valid 151200Z - 161200Z

   ...THERE IS A HIGH RISK OF SEVERE THUNDERSTORMS IN CENTRAL/SOUTHERN
   PARTS OF MS/AL...

   ...SUMMARY...
   A tornado outbreak is likely on Saturday across the central Gulf
   Coast States and Deep South into the Tennessee Valley. Numerous
   significant tornadoes, some of which should be long-track and
   potentially violent, are expected on Saturday afternoon and evening.
   The most dangerous tornado threat should begin across eastern
   Louisiana and Mississippi during the late morning to afternoon,
   spread across Alabama late day into the evening, and reach western
   parts of the Florida Panhandle and Georgia Saturday night.

   ...Central Gulf Coast/Deep South/TN Valley...
   After collaboration with WFOs BMX/JAN/MOB, an upgrade to a level
   5-HIGH risk appears warranted for the most likely corridor of
   potentially violent tornadoes, peaking tomorrow afternoon and
   evening. A broader level 4-MDT risk has been expanded somewhat
   eastward for the nocturnal significant tornado threat.

   An intense mid-level jet, 100-110 kts at 500 mb, will eject through
   the basal portion of a broad southern Great Plains shortwave trough.
   This will induce secondary cyclogenesis along an initially
   slow-moving baroclinic zone from the Ark-La-Tex to the central Great
   Lakes. Another day of air mass modification ahead of this wave will
   yield a pronounced plume of rich northwest Gulf moisture that should
   be pristine across southeast LA and southern MS through late
   morning. As mid-level height falls overspread the diurnally warming
   air mass, increasing convective development is expected along the
   deepening baroclinic zone, as well as residual outflows to its
   northeast in the TN Valley from prior late D1 convection.

   Steep mid-level lapse rates atop the richly moist boundary layer
   will yield at least moderate MLCAPE from 1500-2500 J/kg across
   eastern LA into central MS. Vertically veering wind profiles with
   strong anvil-level divergence amid the favorable instability should
   support robust updrafts and intense supercells. Low-level shear will
   strengthen midday through the afternoon, yielding potential for a
   tornado outbreak. 

   The most probable convective corridor will be along the effective
   outflow boundary across central/northern parts of MS into north AL
   and south TN. Along and south of this will be the most favored
   corridor for long-tracked, discrete supercells. These will likely
   develop within north/south-oriented confluence bands as increasing
   large-scale ascent becomes coincident with the peak heating cycle. 
   A volatile combination of kinematic/thermodynamic parameters will
   support potential for long-track, EF3+ tornadoes. The overall
   spatial extent of this threat will be modulated by the degree of
   boundary-layer heating within the mid to upper 60s dew point plume,
   along with where exactly the large-scale outflow boundary sets up
   from late D1/early D2.

   Significant tornado potential, along with very large hail and
   destructive damaging wind gusts, should persist into Saturday night.
   Greater potential for a broken to linear band of thunderstorms is
   anticipated by this time, but wind profiles will still strongly
   favor supercells. As such, a mix of all three hazards may continue
   with sig severe hail potential favored south and sig severe wind
   favored north as the convective band spreads towards the southern
   Appalachians and the northeast Gulf Coast.

[Hollie Maea]

What is the cause for the disconnect between what people on here are saying vs the SPC? This thread is quite bearish in general while meanwhile the SPC just did the third ever Day 2 high.

[sarcean]

pretty wild watching this move across the US

[ATDoel]

12 minutes ago, Hollie Maea said:

What is the cause for the disconnect between what people on here are saying vs the SPC? This thread is quite bearish in general while meanwhile the SPC just did the third ever Day 2 high.

I'm wondering the same thing, regardless always listen to the SPC and your local NWS!

[WxSynopsisDavid]

NWS Birmingham

[WxSynopsisDavid]

32 minutes ago, Hollie Maea said:

What is the cause for the disconnect between what people on here are saying vs the SPC? This thread is quite bearish in general while meanwhile the SPC just did the third ever Day 2 high.

The disconnect was in relation to the potential fail modes and timing issues. Those have resolved with today’s guidance so far. Reason why NWS SPC and the local NWS offices adjusted accordingly. I can say that if 18z data holds course, most of us on this thread will begin to get an idea of what tomorrow will compare to.

[Brick Tamland]

Alabama has been ground zero for a lot of big tornadoes the past couple of decades. 

[ATDoel]

Just now, Brick Tamland said:

Alabama has been ground zero for a lot of big tornadoes the past couple of decades. 

I think Mississippi might take the crown there, but only just.  I've also noticed our peak tornado season has shifted to March, where historically it's usually been more in April.

[olafminesaw]

3 minutes ago, ATDoel said:

I think Mississippi might take the crown there, but only just.  I've also noticed our peak tornado season has shifted to March, where historically it's usually been more in April.

Pretty darn close

[nwohweather]

Quite possibly the most ominous Day 2 outlook I've ever read. 

The most probable convective corridor will be along the effective
   outflow boundary across central/northern parts of MS into north AL
   and south TN. Along and south of this will be the most favored
   corridor for long-tracked, discrete supercells. These will likely
   develop within north/south-oriented confluence bands as increasing
   large-scale ascent becomes coincident with the peak heating cycle. 
   A volatile combination of kinematic/thermodynamic parameters will
   support potential for long-track, EF3+ tornadoes.

[kayman]

James Spann of WBMA (ABC 33/40)/Birmingham has updated the outlook for Greater Birmingham along with all of Central Alabama.

https://www.alabamawx.com/?p=276258

It is very disturbing and very ominous of a volatile event for South/southwestern MS, most of Alabama, the north and western 2/3rds of Georgia tomorrow through Sunday morning.

 

 

[kayman]

5 hours ago, Brick Tamland said:

Don't think much will happen here in central NC if we don't get some sun in the morning. We usually need some sun to provide the spark for severe storms here. Today has been a lot cooler than forecasted, too 

You might be underestimating the helicity and hodograph forecast for wind shear for Sunday at and east of the Metro Charlotte area. The wind shear will be there.  That is why I have a feeling that an enhanced risk for severe weather outlook might be coming for just east of Charlotte for Central NC and Northeast SC on Sunday morning and midday.  Sunshine isn't always needed for severe weather if the other ingredients such as wind shear, moisture, and latent heating is already present. 

[lilj4425]

9 hours ago, WxSynopsisDavid said:

Not a fan of the sarcasm for an outbreak scenario that is going to be devastating for some. Maybe in the future such banter should be directed to the banter thread.

Live a little. I’m not expecting much severe weather honestly. 

[kayman]

55 minutes ago, lilj4425 said:

Live a little. I’m not expecting much severe weather honestly. 

Speak for yourself.

My immediate family members including my parents live in the Greater Birmingham area of Central Alabama.  I am legitimately concerned for them.

This forum and thread cover the entire Southeast from MS, AL, GA, FL, Southern VA, SC, NC and not just your area. 

Please read the room and have some sense of respect for those of us concerned about the possible severe weather outbreak threat across the Southeast.

[olafminesaw]

16 minutes ago, kayman said:

Speak for yourself.

My immediate family members including my parents live in the Greater Birmingham area of Central Alabama.  I am legitimately concerned for them.

This forum and thread cover the entire Southeast from MS, AL, GA, FL, Southern VA, SC, NC and not just your area. 

Please read the room and have some sense of respect for those of us concerned about the possible severe weather outbreak threat across the Southeast.

I agree, but it does suck that AL & MS don't really have a subforum that's truly theirs. Technically they fall on the western states sub, but nobody posts there from the deep south