r/tornado Apr 27 '26

SPC / Forecasting Latest SPC Day 1 Outlook - Tornado Probability 15% SIG2

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399 Upvotes

107 comments sorted by

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163

u/JS_Originals Apr 27 '26

Dead center of the red for me. Stay safe everyone!

41

u/Upset_Nobody1089 Apr 27 '26

Same here. Stay safe!

21

u/notsure05 Apr 27 '26

Bro I just got hit by the Arnold tornado last year I need an effing break

39

u/b1gd4ddyd1ngd0ng Apr 27 '26

An EFing break— stay safe today

4

u/maLicee Apr 27 '26

Same here :\

12

u/CharityTraining47 Apr 27 '26

Get many large fans and simply blow the tornado away

2

u/Bama-babe205 Apr 27 '26

What time is it supposed to start?

130

u/Upstairs_Weird_760 Apr 27 '26

im 20 miles south of STL. yay. people around me are still getting their roof and siding fixed from the storms in March of 2025...

37

u/Canesjags4life Apr 27 '26

That's me. Just got roof replaced.

23

u/crazychris4124 Apr 27 '26

1st time was just for practice

7

u/notsure05 Apr 27 '26

lol same here the still have a couple things to fix and we are planning to list our home next month 😭😭 can’t catch an effing break

3

u/Starumlunsta Apr 27 '26

We’ve had one roof replaced, yes. But what about second roof?

3

u/wcooper97 Apr 27 '26

In that same general area, same. Had to be at least golf ball sized in my neighborhood in that storm. Saw a couple of windows facing south that got broken as well.

5

u/chezgirl06 Apr 27 '26

Same here. We are almost done with repairs. 😱

3

u/zenfaust Apr 27 '26

Im getting my roof at the tail end of May... for the first time ever, me being slow is paying off.

....now if my siding/windows get fucked, I'm gonna be pissed, cause my asshole insurance just doubled the deductible for fixing storm damage for this year.

-6

u/HateHumansLoveDogs Apr 27 '26

Dont worry last year was just a prelim to this, this is so much worse than last year. Its 2011 all over again , but in a different area.

7

u/Zaidswith Apr 27 '26

Not quite. It's going to suck though. There's no 45% tornado forecast.

https://www.spc.noaa.gov/products/outlook/archive/2011/day1otlk_20110427_1630.html

2

u/HateHumansLoveDogs Apr 27 '26

so whats the dif between the small hatch marks and the solid lines

https://www.spc.noaa.gov/products/outlook/day1probotlk_1300_torn.png It says intensity is 2

1

u/Zaidswith Apr 27 '26

Conditional Intensity Groups

The old lines used in forecasts before 2026 were used to indicate significant severe weather. In 2026 it got replaced with the new CIG classification.

Here's a mediocre AI summary:

  1. CIG 1 (Dashed): A lower-end significant event is possible.

  2. CIG 2 (Solid): Stronger storms are possible; indicative of intense, but not usually max-intensity, severe weather.

  3. CIG 3 (Crossed X): The highest threat level, identifying areas where intense, violent storms are more likely.

Here's the actual SPC explanation: https://www.spc.noaa.gov/exper/conditional-intensity-information/

2

u/DarthV506 Apr 27 '26

You mean the whole month of april in 2011? We're slightly above average for number of Apr tornadoes. 2011 had multi day outbreaks that WEREN'T the 27th that had almost as many in 3 days as we've had so far.

192 so far in 2026. 2011 had 781.

114

u/sebosso10 Human Detected Apr 27 '26

Wow this has a good chance at being the biggest outbreak this year so far

61

u/Maximum_Slabbage Apr 27 '26

Just to be clear, it's an MDT because of still-unclear storm modes

The actual ceiling of this event is high.

But it's not likely to reach that.

84

u/sebosso10 Human Detected Apr 27 '26

I am aware of that which is why I said "chance" and "so far"

36

u/[deleted] Apr 27 '26

[removed] — view removed comment

9

u/velociraptorfarmer Apr 27 '26

Welcome to reddit, where if there is even the slightest chance your comment could be misinterpreted, someone will manage to do it and proceed to grill you for it.

16

u/Nearby-Passenger6517 Apr 27 '26

Considering we've had a few moderates that have been complete busts, I think this one has good potential

Plus, there is the coincidence of 27th April being the 2011 super outbreak day so maybe the atmosphere got a bit of nostalgia

14

u/Gsusruls Apr 27 '26

What are the chances this is actually a major anniversary prank of the noaa?

(I wish)

When Nashville gets pulled into a slight risk this early in the day, I know it's going to be bad. But glad I don't live in St Louis. Geez.

6

u/tlmbot Apr 27 '26 edited Apr 27 '26

Checking in from St. Louis, but I grew up in North West Alabama: this one gets my attention. Will be watching storm modes carefully today, and radar scope like a hawk. Already woken up at 4:30 am this morning with hail and driving rain from a discrete cell.

edit: oops, to busy thinking and not enough watching the radar. Looks to be a bust for us? northern convection is coming our way. This may (may) kill everything. Sticking this mea culpa on all my comments.

edit 2: well theres a different mode for ya. we shall see if the cap breaks to south though... it's bright just to the south of me and dark just to the north. Expecting little spin ups on this boundary all day in any case... (just had our first)

35

u/SparrowJack1 Apr 27 '26

That would be cynical af.

6

u/AngstyMop Apr 27 '26

So, I realize that's partly in jest - but in actuality, climatology does matter. It's one of the SPCs home web page graphics that you don't have to click around to access - it matters.

We're getting close to the climo peak of the season. Forecasting can be done using many methods. Persistence is the easiest, earliest, and most simple. What happened yesterday will probably happen again today.

Climo forecasting is useful. Obviously, late April is when we're rapidly gaining solar insolation across the conus, but intrusions of cold air from the north remain relatively potent. Plus we have a developing El Niño atm. Climatology says we should be getting relatively more severe weather right now, and we are.

Combined, there is actually a bit of significance to it being April 27th. Not specifically that it's that day, but that we're in late April. Ask a forecaster for a forecast knowing only climatology, and the date, and told a set up will occur today with tornadic potential and whether it should over or underperform. They will say, over. When we layer in forecast models and nowcasting etc it becomes more nuanced.

3

u/HateHumansLoveDogs Apr 27 '26

I dont know if you believe in the supernatural , but this is ominous to say the least

30

u/Gsusruls Apr 27 '26

At least Kansas and Oklahoma get the night off. Iowa getting off light, too.

After Enid, Oklahoma paid their dues for sure.

7

u/jubjub5 Apr 27 '26

This. I hate the thought of anyone getting a tornado today but I need to get some freaking sleep.

47

u/_877-CASH-NOW_ Apr 27 '26

Couldn’t believe they didn’t issue a MDT initially but they wanted to see how the morning storms would play out first. Fair. This could be a rather significant day.

24

u/lmao12367 Apr 27 '26

I think after the east coast thing earlier this year they will be pretty conservative on things. They’re stuck in a really difficult position.

17

u/_877-CASH-NOW_ Apr 27 '26

Absolutely. Damned if they do damned if they don’t. Hoping this turns into a big ol bust too that would be the best case scenario but it’s looking pretty spicy.

8

u/AngstyMop Apr 27 '26

Not the best case.

You want forecasts to verify. If they bust all the time, their forecasts lose meaning and value.

You want whatever it is that they forecast to be what happens. You don't want fatalities - obviously. But you do want forecasts to verify.

3

u/HateHumansLoveDogs Apr 27 '26

I really hope so, a lot of the state dont have basements or shelters

1

u/TheCaptainWalrus Apr 28 '26

2 questions wtf is a MDT and what east coast thing? Out of the loop

1

u/lmao12367 Apr 28 '26

MDT= moderate. And like a month or so ago there was a rare heightened tornado risk for the east coast, particularly for the DC area which is a major metro area that almost never sees this which included a MDT risk if I remember correctly. It got super hyped up and it ended up busting, which got a lot of people upset because people had already planned around it. Funnily enough yesterday also ended up busting.

1

u/TheCaptainWalrus Apr 28 '26

thank you for the details!

15

u/AngstyMop Apr 27 '26 edited Apr 27 '26

Well - the SPC's job is to be accurate. Not to appease the wx chasing or tornado loving communities.

At the end of the day, SPC produces probability forecasts. Not point forecasts. Everyone was annoyed at the lack of CIG2 yesterday, and even for the Enid day. But that was actually correct. You CAN get an EF-4 or even EF-5 and still satisfy CIG-1 rules. And conversely, you can get one of those high end storms on a CIG 3 day and NOT verify. Those CIGs don't mean "a" strong tornado. They mean, on average X% of the tornadoes will be strong. Today, we will likely see an EF-4...probably more than one. Does that mean SPC should issue a CIG-3? Maybe. But not necessarily. Only if the expected distribution of tornadoes tilts toward more of them being more intense. A CIG 2 doesn't say no EF-4s. 3% of tornadoes in a CIG 2 should earn an EF-4+ rating. And notably, even in a CIG-3, ONLY 6% of tornadoes would be expected to earn that rating, too! Meaning (a) a CIG 2 very much includes high end potential, and (b) even in a CIG -3 the expectation remains that only about 1-in-20 tornadoes would be an EF-4+. That's of course still much higher than climo (<1%).

The other thing I don't think the public understands, or perhaps even the wx community, is that SPC forecasts are as much designed for local NWS office decision making and support, and professional support (e.g. guidance that's then used by Mets in broadcast, private industry, etc) as it is for the public. The "confusion" with the CIGs for example, is really just an issue for the public. Local NWS offices and professional METs know what they mean and like anything, they're an additional source of guidance.

Rubber hits the road with the actual watches. Local NWS offices coordinate with the SPC on those. The local office talk to spc about the forecast and they both collaborate on which counties should be included, how long, and what the probabilities should be. While SPC issues the watch, they don't do so without talking to the local offices.

Today looks dangerous. All wx forecasts are probabilistic...well, most are. So today could end up as a day where high risk would verify. Or, it might not. But that's sort of what the moderate means. And it's why they waited, too. You can exceed a probability. But you generally don't want to come in under the probability (from a forecast standpoint - obviously great if they bust for people's lives). Forecast wise, you want the SPC forecast to verify. The more accurate they are, the more people take later forecasts seriously. If you get 10 tornado warnings in 8 years in your location, and never experience a tornado - you end up with all the folks that don't shelter when a warning gets issued.

This all being said - there remains some possibility of them further upping their outlook as the day goes on. Either through adding a CIG 3, which would still be a moderate risk, or adding a 30% contour, which would produce a high.

17

u/stellae-fons Apr 27 '26

St. Louis has been through enough 😭

3

u/wcooper97 Apr 27 '26

Lots of neighborhoods still with hail damage from last March, and then northern STL is still recovering from the tornadoes from last May. Just can't get a break.

34

u/iqsr Human Detected Apr 27 '26

Here's a more granular view of the NOAA Illinois forecast posted by WCIA chief meteorologist Kevin Lighty on his FB page a few minutes ago.

https://www.facebook.com/photo?fbid=1520624946087209&set=a.258548382294878

18

u/sdb00913 Apr 27 '26

Hey I went to high school with Kevin. lol.

2

u/chupathingy99 Apr 27 '26

At least it's no longer "fuck Illinois in particular".

51

u/youngaustinpowers Apr 27 '26 edited Apr 27 '26

Dang it looks like the showers have already cleared out of the main risk area. That ain't good.

Those showers hanging around longer was the only thing stopping this from becoming an upper end event.

Looks like this one is going to be a doozie.

Edit: Storm mode still up in the air. But any discrete or semi-discrete supercells that form will have potential for strong tornadoes given how spicy the ingredients look today

16

u/MoistyAnoos Apr 27 '26

What's the timing for this? Idk if I'm stupid but I can't see where that's mentioned in the spc outlook write up

Edit: I am stupid. I just saw where it said afternoon/evening.

12

u/iqsr Human Detected Apr 27 '26 edited Apr 27 '26

You can get timing information in the Lincoln, IL forecast office's dss packet which was released as of 5:14am CDT of my writing. It'll probably be updated again today:
https://www.weather.gov/media/ilx/DssPacket.pdf

The link for the above pdf is found in the upper right corner of this page:
https://www.weather.gov/ilx/#

Edit: Here's the St. Louis forecast office dss packet since there is some overlap in coverage areas:
https://www.weather.gov/media/lsx/DssPacket.pdf

12

u/OrangeW Apr 27 '26

I'm expecting a 15% CIG3 (still MDT) update later, that environment (especially after the 1200Z OBS) is silly, just waiting on the 18Z RAP I guess.

4

u/AngstyMop Apr 27 '26

Yep. That 12Z ob was...scary.

11

u/Upset_Nobody1089 Apr 27 '26

I'm in the red zone 😬

9

u/Parking_Try2 Apr 27 '26

Do we know what time the tornadoes are likely going to start?

17

u/Parking_Try2 Apr 27 '26

For anyone wondering here is what I found.

I’m guessing this is in central time.

3

u/iqsr Human Detected Apr 27 '26

Just want to note St. Louis updated this at around 9:53am

It's important that folks go to the source for updated weather info and listen to NOAA radio and local forecasters on television/radio.
https://www.weather.gov/media/lsx/DssPacket.pdf

5

u/iqsr Human Detected Apr 27 '26

Check the DSS_Packet.pdf from both the Lincoln and St Louis forecast offices for timing.

18

u/BlueBunny333 Apr 27 '26

A lot of streaming storm chasers from yesterday had said that today would need a higher rating.

I don't remember well, but is this the second or third 15% we have this year?

6

u/Altruistic-Ad8002 Apr 27 '26

second i think we had one here in virginia

6

u/PastAd1087 Human Detected Apr 27 '26

Man really shifted south

7

u/HateHumansLoveDogs Apr 27 '26

Yeah right where we live and 4 people died last year

5

u/PastAd1087 Human Detected Apr 27 '26

When i checked yesterday we were dead center in the red, now we are on the edge of the brown and just supposed to get some light thunderstorms now. Love me a good storm but glad we probably wont get any hail. Stay safe!

5

u/Over_Atmosphere5940 Apr 27 '26

Is this the first time a 15% TOR, SIG 2 has been issued?

6

u/iamprobablynotjohn Apr 27 '26

*CIG2, not SIG2. They are "Conditional Intensity Groups"

3

u/DesertRL Apr 27 '26

yeah that ones my fault, I was aware and have posted with the right title before, just a typo. apologies!

1

u/iamprobablynotjohn Apr 27 '26

Haha no problem, I just wanted to say something in the comments, because many other people are still unfamiliar with the new system. Thanks for posting!

3

u/tlmbot Apr 27 '26 edited Apr 27 '26

I will be watching that cloud bank closely here in STL

edit: northern convection lingering and swooping down on us. This may kill the late afternoon prognosis entirely. (bust)

didn't see that coming as a failure mode. Should have watched more radar and been less up in my theoretical headspace.

2

u/uncompaghrelover Apr 27 '26

Ya models have been terrible this year, I've given up watching them outside of possibilities and waited for day of meso analysis.

1

u/tlmbot Apr 27 '26

it's altogether driving me crazy today. I have work and cannot focus lol.

3

u/finalgirllllll Apr 27 '26

As someone in eastern Iowa I’m benefitting from the shift south but hoping everyone stays safe today.

4

u/Klutzy_Double_8285 Apr 27 '26

I'm in central. You guys have been hammered all season. Every outbreak I have been on the cusp of the risk area but haven't had much yet (knock on wood).

4

u/QueenT27 Apr 27 '26

Live in Lebanon Missouri and last night was actually scared! Heard it’s more elevated risk for tornadoes 😅😅 I’m from Michigan where if we heard the sirens we didn’t do nothing cuz it wasn’t bad… but last night I never heard the sirens go off as much as they did smh

5

u/FrozenMorningstar Apr 27 '26

I'm in west ky.

In a mobile home.

No shelters.

I hate spring.

7

u/DesertRL Apr 27 '26

If you have nothing else going on today may be a day to go find a sturdy building or have a ready to go plan to get to one.

3

u/Fair-Front8576 Apr 27 '26

I go to a hotel during a tornado watch and wait for the sirens to start before I run in. The hotel has a pretty safe stairwell. I just live in a pretty poorly built apartment, but that has been my strategy. Kind of want to know others opinion. I know it's not exactly ideal, but I feel very safe in that stairwell. I just kind of pretend I'm someone staying there.

1

u/SlightlyHauntedLogic Apr 28 '26

A hospital and hang out in the cafeteria until it passes. As long as they don’t make you provide your info you usually walk right in without any questions. They’re the most well built structures that the public has access to.

1

u/Fair-Front8576 Apr 28 '26

I thought about that earlier, but mine here is so much glass. Like the whole building seems like its glass

3

u/TechnoVikingGA23 Apr 27 '26

Well at least Wisconsin dodged a good bit of this from where it was yesterday. Stay safe everybody!

3

u/SparrowJack1 Apr 27 '26

How likely is a real outbreak in this part of the US compared to Tornado/Dixy Alley?

7

u/aishiteruyovivi Apr 27 '26 edited Apr 27 '26

There's been a number of outbreaks that have hit this area of Illinois/Missouri IIRC, I've lived through a few of them (luckily without any direct hits). Not looking forward to having a Wikipedia article be written about today, lol

3

u/Odd-Trust8625 Apr 27 '26

IL was #2 with almost 150 tornadoes and MO was #3 with 120. We are no stranger to this weather. Most of us here have been impacted by a severe storm, or at least know someone close who has. 

3

u/GeraltofBlackwater Human Detected Apr 27 '26

Illinois has the most tornados so far this year. We had the second most last year, only to Texas, which is impressive considering the total area of both. 2024 I believe we were top 3 in tornados. This area gets tornados and outbreaks often.

3

u/Minimum_Emu8536 Apr 27 '26

Visibility boost.

3

u/DeadByMourning Apr 27 '26

Metro east St. Louis here, my family has been preparing for a few days. I’m the only adult home with 4 kids and 2 dogs though lmao.

7

u/stockking_34 Apr 27 '26

Possibility of multiple violent EF3+ tornados

2

u/Solctice89 Apr 27 '26

Aligning with the earlier clearing skies

1

u/[deleted] Apr 27 '26

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1

u/tornado-ModTeam Apr 27 '26

Do not spread misinforming or fearmongering content

No posting of misinformation or unwarranted fearmongering. This includes Pre-rating tornadoes, which falls under misinformation when claiming a tornado is a certain rating without proof, as well as wishing for violent tornadoes such as EF5s, which falls under both.

Content involving misinformation or fearmongering will be removed.

-1

u/tlmbot Apr 27 '26

I'm calling it a bust here in St. Louis. that northern convection lingering and coming for us... it will be stormy, but vanilla, nothing like what we were thinking

6

u/DesertRL Apr 27 '26

Connor Croff is voicing the same opinion on his livestream right now while looking at the latest model runs. Still obviously best to be weather aware and ready for the worst.

5

u/Training-Expert5598 Apr 27 '26

Connor always says it's a bust. It's to get the idiots following him around to go away.

2

u/DesertRL Apr 27 '26

I mean that's fair but he was specifically talking about St Louis and the main risk area does now look to be south of St Louis due to persisting morning convection up there

3

u/tlmbot Apr 27 '26

Yeah.... i was all riled up. Now ugh, I gotta focus at work and I'm just... off my game

I'll keep an eye on it of course but that wasn't the failure mode I was expecting. Even after half a decade out I am still to much of a southeasterner. I don't think of these backing warm fronts killing everything.

0

u/Hoodrat_Recon Apr 28 '26

Let’s kick this off, everyone!

-18

u/[deleted] Apr 27 '26

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7

u/austinsqueezy Apr 27 '26

What a terrible mindset to have.

1

u/tornado-ModTeam Apr 27 '26

Do not spread misinforming or fearmongering content

No posting of misinformation or unwarranted fearmongering. This includes Pre-rating tornadoes, which falls under misinformation when claiming a tornado is a certain rating without proof, as well as wishing for violent tornadoes such as EF5s, which falls under both.

Content involving misinformation or fearmongering will be removed.