March 17-18 Severe Weather Event

[NorthHillsWx]

Take the high risk piece out of the SPC’s forecast and that moderate risk area was spot on. Not a bad forecast by any means. 

[PackGrad05]

Would you say that the probability of no tornados per unit area in a high risk area is the same as a tornado per unit area in the slight risk area?  

Areas in the high risk had tornados.  A majority of the tornado reports (as of that graphic) were in the high area.  What percentage of the high risk area needs to have a tornado for it not to be considered a bust?  

You could argue that sliver of the slight was also a bust since it had numerous warnings and a tornado report... or could you?

 

[Quincy]

3 minutes ago, PackGrad05 said:

Would you say that the probability of no tornados per unit area in a high risk area is the same as a tornado per unit area in the slight risk area?  

Areas in the high risk had tornados.  A majority of the tornado reports (as of that graphic) were in the high area.  What percentage of the high risk area needs to have a tornado for it not to be considered a bust?  

You could argue that sliver of the slight was also a bust since it had numerous warnings and a tornado report... or could you?

 

This is a time sensitive version of the PPF (practically perfect forecast):

There is some debate that the CIPS PPF method isn’t the best. I’d reference Gensini’s enhanced version tomorrow, once it updates. 
https://atlas.niu.edu/pperfect

[the ghost of leroy]

TORCON 9 

[yoda]

1 hour ago, David Reimer said:

Perhaps I wasn't being sarcastic after all. One of those failure modes came to fruition this evening. There were certainly several tornadoes this afternoon in portions of Mississippi and Alabama. A few of them were significant (EF2+). Was today a 'high risk caliper event'? I'm leaning towards no. I don't fault the 06Z forecaster as their small high risk was placed alright. The 45% tornado late this morning and the continuation of the high risk at 01Z? You've got to be freaking kidding me. There's a rain shield with a few lightning strikes blasting across that 01Z high risk. There aren't even any severe storms in the rain shield! I'm afraid today will add a 'crying wolf' syndrome to some residents in those regions. They sure haven't forgotten April 27, 2011 - but we're coming up on the ten year anniversary. Today's tornado probabilities were identical to those on April 27, 2011. I don't expect every high risk to be a generational outbreak, but I sure do expect more than what we got today. One long-track tornado does not verify a 'high risk'. One EF2+ tornado does not verify a high risk (although I bet we do see at least two from this afternoon's activity). 

Jeff disagrees strongly

https://mobile.twitter.com/VORTEXJeff/status/1372373456629731330

[cheese007]

9 minutes ago, Quincy said:

This is a time sensitive version of the PPF (practically perfect forecast):

There is some debate that the CIPS PPF method isn’t the best. I’d reference Gensini’s enhanced version tomorrow, once it updates. 
https://atlas.niu.edu/pperfect

That's actually a really neat tool! Another fun time sink avoiding real work lol

[janetjanet998]

20 minutes ago, PackGrad05 said:

Would you say that the probability of no tornados per unit area in a high risk area is the same as a tornado per unit area in the slight risk area?  

Areas in the high risk had tornados.  A majority of the tornado reports (as of that graphic) were in the high area.  What percentage of the high risk area needs to have a tornado for it not to be considered a bust?  

You could argue that sliver of the slight was also a bust since it had numerous warnings and a tornado report... or could you?

 

I think that some people think it "busted" because those Tornadoes happened rather early and were not part of a second "main event" of long tracked tornadoes moving from MS into AL in the evening that never materialized

just for the record as I have said before  over the years, I don't think there is sucha  thing as a "bust" since its a RISK factor...but then again I'm old fashioned

A high probability,   or risk,  of something happing doesn't mean it will happen every time 

 

[MattPetrulli]

Cells in NE AL beginning to show more signs of developing, embedded mesocyclones. 

[jrips27]

 

[janetjanet998]

5 minutes ago, MattPetrulli said:

Cells in NE AL beginning to show more signs of developing, embedded mesocyclones. 

2 TOR warned now

LLJ working its magic as usual starting this time at night in the SE

 

[Witness Protection Program]

26 minutes ago, NorthHillsWx said:

Thanks for the graphic pack, I stand corrected on my “most tornadoes occurred outside the high risk area statement.” However, it was definitely along the extreme southern and eastern edges. The vast majority of the area, the absolute highest level they can give for an outbreak, saw little to no severe weather. Definitely gives the impression of a bust 

I understand your point, but OTOH, 16 of 20 reports being in the center oval seems pretty darn impressive for more than just archery.

I've lived long enough to still be continually amazed at how good weather forecasting has become.  So my acceptable margin of error may be bigger than that of others.

[nwohweather]

This wasn’t a bust. Not legendary so probably didn’t deserve a high risk, but absolutely lived up to a Moderate risk type event. It’s like forecasting 12” of snow and getting 8”. Sure the foot would’ve been cool but it’s still a lot of snow.

I will continue beating the drum that I think tomorrow could wind up being worse. I noticed backing in the hodographs and a possibility of left movers tomorrow definitely increasing the large hail threat. Truthfully it’ll be a perfect day to camp out around Orangeburg and hop on 95 or 26 to chase. I’d be shocked honestly if there is not a violent tornado in SC tomorrow

[Chinook]

most intense rotation tracks from several hours ago (total of 4 hours)

[yoda]

New Day 1... wow.  The huge MOD risk from the Day 2 basically disappeared into a small MOD risk in SE NC/NE SC... even the ENH risk area is smaller.  The 45 percent contour and hatched wind are gone... down to large 30 percent now.  Large 30 percent hail gone... down to large 15 percent.

Disco explains why pretty well too

[Santa Clause]

Yup it’s going to be very localized threat.

[Dustin]

CC drop between Dotham and Enterprise AL this morning.  

[NorthHillsWx]

Tight couplet just west of Kinsey 

[NorthHillsWx]

Looks like it could be showing a debris signature 

[NorthHillsWx]

Certainly looks to be a TOG near Blakely 

[NorthHillsWx]

[NorthHillsWx]

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 AM EDT FOR
NORTHEASTERN EARLY COUNTY...

At 746 AM EDT, a confirmed tornado was located 7 miles east of
Blakely, moving east at 40 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

[NorthHillsWx]

Looks like we’ve had multiple tornado  touchdowns this morning but thankfully most have been short lived and don’t appear to be too severe

[Brick Tamland]

Once again the clouds hang around here and looks like the wedge holds on and wins again.  We have seen it time and time again. People that aren't even mets were predicting this would happen here today. It is what has been happening 9 out of 10 times here the last decade whenever we have a supposedly big threat. It feels like the models are just fooling us time and time again and don't know how to handle things in our current climate.  Same thing happens all the time with winter storm threats, too. Bad thing is the local mets have been really hyping the threat here today, and the one time it actually does happen people won't be listening. 

[Justicebork]

Charge your phone.

[NorthHillsWx]

4 minutes ago, Brick Tamland said:

Once again the clouds hang around here and looks like the wedge holds on and wins again.  We have seen it time and time again. People that aren't even mets were predicting this would happen here today. It is what has been happening 9 out of 10 times here the last decade whenever we have a supposedly big threat. It feels like the models are just fooling us time and time again and don't know how to handle things in our current climate.  Same thing happens all the time with winter storm threats, too. Bad thing is the local mets have been really hyping the threat here today, and the one time it actually does happen people won't be listening. 

Agreed, but it I’ll give RAH kudos- they outlined the limiting factors through their discussions on today’s threat. 
 

WRAL mentioned there’s a high bust potential with today’s threat on their morning news. I’m thinking wedge wins out, based on it being 49 and drizzly with a northeast wind and a system progged to arrive earlier than previously forecast, giving even less time to destabilize 

[eyewall]

4 minutes ago, NorthHillsWx said:

Agreed, but it I’ll give RAH kudos- they outlined the limiting factors through their discussions on today’s threat. 
 

WRAL mentioned there’s a high bust potential with today’s threat on their morning news. I’m thinking wedge wins out, based on it being 49 and drizzly with a northeast wind and a system progged to arrive earlier than previously forecast, giving even less time to destabilize 

Yep. 50F and drizzle isn't going to get the job done.

[PackGrad05]

both RAH and local Mets have said that the warm air really wouldn’t surge up here until after 12 noon if it did.   So I’ll hold off on until tonight to see if things remain stable.   
It’s only 9:55am

[nwohweather]

I’m overly bullish on today. Maybe I’ll get egg on my face but around 1-3 today it’s showing solid instability and helicity levels of 200-400 on top of the storms that spark up. 67° in Charleston at the moment

[Cheeznado]

I chased a really great supercell in Central Alabama yesterday west and SW of Selma. Best SE storm structure I have seen in my 41 years here. Go to https://www.facebook.com/cheeznadophoto

[OpAck]

Down in Wilmington, we're at 70 degrees and there have been a few peeks of sun. Schools in the area are now on a 2-hour early dismissal.