April 11-13, 2022 | Tornado Outbreak

[ClicheVortex2014]

SPC forecasters draw synoptic maps for every event. Here’s the one for today

 

[ClicheVortex2014]

4 minutes ago, StormfanaticInd said:

Wonder if they will issue a moderate risk for tomorrow 🤔 

I'm sure it'll be issued by the time the event starts tomorrow. My question is if we'll see it in the next hour. I think it's more likely than not, but I could also see them be cautious with the potential for morning convection in the area.

[Iceresistance]

CAPE is over 3500 in NW Oklahoma, CINH is below 100 now, the Daytime heating is doing it's work by eroding the cap & increasing the instability.

[ClicheVortex2014]

Nasty supercell in N IA tonight but HRRR is hinting at some low-level stability. If that verifies, the supercell will have issues putting down a tornado. If the low-levels turn out to be even slightly unstable, there'll be a huge tornado threat.

I'm wondering if some storm-scale or local-scale processes will occur to feed the supercell warmer air than HRRR is showing. I think even 5 degrees warmer would make a significant difference.

Edited April 12, 2022 by ClicheVortex2014

[ElectricStorm]

[ClicheVortex2014]

Smallish day 2 moderate risk for tornadoes issued. Larger 45% hatched winds. Could be the biggest overall severe weather day of the year so far

 

DAY 2 CONVECTIVE OUTLOOK    
NWS STORM PREDICTION CENTER NORMAN OK  
1229 PM CDT TUE APR 12 2022  
  
VALID 131200Z - 141200Z  
  
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LOWER TO MID MS  
RIVER VALLEY...  
   
..SUMMARY  
  
NUMEROUS SEVERE THUNDERSTORMS APPEAR LIKELY ACROSS A LARGE PORTION  
OF THE LOWER/MID MISSISSIPPI VALLEY INTO THE MIDWEST, AND LOWER OHIO  
VALLEY ON WEDNESDAY. DAMAGING WINDS, SOME OF WHICH COULD BE  
SIGNIFICANT, SEVERAL TORNADOES (SOME STRONG), AND LARGE TO VERY  
LARGE HAIL WILL LIKELY OCCUR.  
   
..SYNOPSIS  
  
AN UPPER-LEVEL WAVE, CURRENTLY SHIFTING INTO THE NORTHERN PLAINS,  
WILL LARGELY MEANDER OVER THE NORTHERN CONUS FOR THE NEXT 24-48  
HOURS. AT THE SURFACE, A STRONG COLD FRONT ASSOCIATED WITH THE  
ATTENDANT SURFACE LOW WILL CONTINUE TO SURGE TO THE EAST/SOUTHEAST  
ACROSS THE MS RIVER VALLEY THROUGH THE DAY. THE LOW TO MID-LEVEL  
COLD SURGE BEHIND THE FRONT WILL HELP PIVOT THE UPPER-LEVEL TROUGH  
AXIS INTO THE GREAT LAKES BY LATE WEDNESDAY. THIS WILL FAVOR BROAD  
HEIGHT FALLS ACROSS THE NORTHERN MS VALLEY INTO THE GREAT LAKES.  
THIS BROAD SCALE ASCENT, COMBINED WITH CONTINUED POLE-WARD ADVECTION  
OF HIGHER THETA-E AIR AHEAD OF THE FRONT, WILL HELP DESTABILIZE A  
BROAD REGION FROM THE LOWER MS VALLEY INTO THE GREAT LAKES.  
STRENGTHENING FLOW ALONG/AHEAD OF THE FRONT WILL SUPPORT WIDESPREAD  
ORGANIZED CONVECTION.   
   
..MID-MS/LOWER OH RIVER VALLEYS  
  
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE COLD FRONT BY THE  
MID MORNING HOURS ACROSS PARTS OF SOUTHERN MO/NORTHERN AR. MEAN  
STORM MOTIONS ALONG THE FRONT WILL FAVOR A QUICK TRANSITION FROM  
QUASI-DISCRETE CELLS TO MORE LINEAR STORM MODES. CONVECTION WILL  
CONTINUE TO GROW UPSCALE AS IT APPROACHES THE MID-MS RIVER VALLEY  
AMID INCREASING LOW-LEVEL MOISTURE AND DAYTIME HEATING. INCREASING  
LOW-LEVEL FLOW (UP TO 50-60 KNOTS BETWEEN 925-850 MB) WILL LIKELY  
SUPPORT BOWING SEGMENTS AND THE POTENTIAL FOR WIDESPREAD DAMAGING  
WINDS. THE POTENTIAL FOR MULTIPLE 65+ KNOT WIND REPORTS AND/OR  
SIGNIFICANT WIND DAMAGE SUPPORT AN UPGRADE TO A WIND-DRIVEN MODERATE  
RISK FOR PORTIONS OF THE MID-MS/LOWER-OH RIVER VALLEYS. ELONGATED  
0-3 KM HODOGRAPHS AHEAD OF THE LINE WILL ALSO SUPPORT EMBEDDED  
CIRCULATIONS. THE WARM ADVECTION REGIME AND BROAD SCALE ASCENT AHEAD  
OF THE LINE MAY SUPPORT A FEW MORE DISCRETE CELLS ACROSS THE LOWER  
OH RIVER VALLEY BY MID TO LATE AFTERNOON. THIS POTENTIAL MAY BE  
CONDITIONAL ON THE DEGREE OF DESTABILIZATION THAT CAN OCCUR BEHIND  
EARLY-MORNING RAIN/WEAK THUNDERSTORMS THAT SHOULD EXIT THE REGION BY  
EARLY AFTERNOON. HOWEVER, IF DISCRETE CONVECTION CAN BECOME  
ESTABLISHED, ALL HAZARDS WILL BE POSSIBLE, INCLUDING THE POTENTIAL  
FOR LARGE HAIL AND STRONG TORNADOES.  
   
..LOWER MS RIVER VALLEY  
  
THE SURFACE COLD FRONT WILL LIKELY LAG TO THE WEST ACROSS THE  
TEXARKANA/LOWER MS VALLEY REGIONS, BUT THIS WILL ALLOW FOR SEVERAL  
HOURS OF DAYTIME HEATING BETWEEN CLOUD BREAKS AND CONTINUED  
BOUNDARY-LAYER MOISTENING AMID LOW-LEVEL THETA-E ADVECTION. WITH 7-8  
C/KM MID-LEVEL LAPSE RATES ATOP A DEEP, MOIST BOUNDARY LAYER WILL  
LIKELY SUPPORT UPWARDS OF 1500-2500 J/KG MLCAPE BY LATE AFTERNOON.  
GLANCING UPPER-LEVEL ASCENT FROM THE SYNOPTIC WAVE TO THE NORTH  
COMBINED WITH ISENTROPIC ASCENT AND LIFT ALONG ANY CONFLUENCE AXES  
AND/OR LINGERING OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION,  
SHOULD BE SUFFICIENT FOR ISOLATED TO SCATTERED THUNDERSTORMS BY MID  
TO LATE AFTERNOON. ADEQUATE DEEP-LAYER SHEAR AND STRONG FLOW IN THE  
0-3 KM LAYER WILL BE FAVORABLE FOR SUPERCELLS WITH ALL SEVERE  
HAZARDS POSSIBLE. SOME SOLUTIONS HINT AT FORECAST ESRH VALUES  
BETWEEN 300-400 M2/S2, WHICH WILL SUPPORT THE POTENTIAL FOR STRONG  
TORNADOES. THE SIGNAL FOR ISOLATED CONVECTION IS NOTABLE IN RECENT  
CAM SOLUTIONS AND IN ENSEMBLE GUIDANCE, WARRANTING AN UPGRADE TO A  
MODERATE RISK WHERE THE TORNADO POTENTIAL IS HIGHEST.   
   
..NEW YORK AND PENNSYLVANIA  
  
A WEAK UPPER-LEVEL DISTURBANCE, CURRENTLY MOVING OVER CENTRAL TX, IS  
FORECAST TO MOVE INTO THE NORTHEAST BY PEAK DAYTIME HEATING  
WEDNESDAY. A WEAK SURFACE LOW ATTENDANT TO THIS WAVE WILL FAVOR A  
RETURN TO ONSHORE FLOW WITH INCREASING BOUNDARY-LAYER MOISTURE  
THROUGH THE DAY. ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE BY  
LATE AFTERNOON AS THE WAVE MOVES ACROSS THE REGION, AND DEEP-LAYER  
SHEAR SHOULD BE SUFFICIENT TO SUPPORT A FEW STRONG TO SEVERE  
THUNDERSTORMS WITH AN ATTENDANT RISK FOR HAIL, WIND, AND POSSIBLY A  
BRIEF TORNADO.  

 

Edited April 12, 2022 by ClicheVortex2014

[StormfanaticInd]

4 minutes ago, ClicheVortex2014 said:

Smallish day 2 moderate risk for tornadoes issued. Larger 45% hatched winds. Could be the biggest overall severe weather day of the year so far

 

DAY 2 CONVECTIVE OUTLOOK    
NWS STORM PREDICTION CENTER NORMAN OK  
1229 PM CDT TUE APR 12 2022  
  
VALID 131200Z - 141200Z  
  
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LOWER TO MID MS  
RIVER VALLEY...  
   
..SUMMARY  
  
NUMEROUS SEVERE THUNDERSTORMS APPEAR LIKELY ACROSS A LARGE PORTION  
OF THE LOWER/MID MISSISSIPPI VALLEY INTO THE MIDWEST, AND LOWER OHIO  
VALLEY ON WEDNESDAY. DAMAGING WINDS, SOME OF WHICH COULD BE  
SIGNIFICANT, SEVERAL TORNADOES (SOME STRONG), AND LARGE TO VERY  
LARGE HAIL WILL LIKELY OCCUR.  
   
..SYNOPSIS  
  
AN UPPER-LEVEL WAVE, CURRENTLY SHIFTING INTO THE NORTHERN PLAINS,  
WILL LARGELY MEANDER OVER THE NORTHERN CONUS FOR THE NEXT 24-48  
HOURS. AT THE SURFACE, A STRONG COLD FRONT ASSOCIATED WITH THE  
ATTENDANT SURFACE LOW WILL CONTINUE TO SURGE TO THE EAST/SOUTHEAST  
ACROSS THE MS RIVER VALLEY THROUGH THE DAY. THE LOW TO MID-LEVEL  
COLD SURGE BEHIND THE FRONT WILL HELP PIVOT THE UPPER-LEVEL TROUGH  
AXIS INTO THE GREAT LAKES BY LATE WEDNESDAY. THIS WILL FAVOR BROAD  
HEIGHT FALLS ACROSS THE NORTHERN MS VALLEY INTO THE GREAT LAKES.  
THIS BROAD SCALE ASCENT, COMBINED WITH CONTINUED POLE-WARD ADVECTION  
OF HIGHER THETA-E AIR AHEAD OF THE FRONT, WILL HELP DESTABILIZE A  
BROAD REGION FROM THE LOWER MS VALLEY INTO THE GREAT LAKES.  
STRENGTHENING FLOW ALONG/AHEAD OF THE FRONT WILL SUPPORT WIDESPREAD  
ORGANIZED CONVECTION.   
   
..MID-MS/LOWER OH RIVER VALLEYS  
  
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE COLD FRONT BY THE  
MID MORNING HOURS ACROSS PARTS OF SOUTHERN MO/NORTHERN AR. MEAN  
STORM MOTIONS ALONG THE FRONT WILL FAVOR A QUICK TRANSITION FROM  
QUASI-DISCRETE CELLS TO MORE LINEAR STORM MODES. CONVECTION WILL  
CONTINUE TO GROW UPSCALE AS IT APPROACHES THE MID-MS RIVER VALLEY  
AMID INCREASING LOW-LEVEL MOISTURE AND DAYTIME HEATING. INCREASING  
LOW-LEVEL FLOW (UP TO 50-60 KNOTS BETWEEN 925-850 MB) WILL LIKELY  
SUPPORT BOWING SEGMENTS AND THE POTENTIAL FOR WIDESPREAD DAMAGING  
WINDS. THE POTENTIAL FOR MULTIPLE 65+ KNOT WIND REPORTS AND/OR  
SIGNIFICANT WIND DAMAGE SUPPORT AN UPGRADE TO A WIND-DRIVEN MODERATE  
RISK FOR PORTIONS OF THE MID-MS/LOWER-OH RIVER VALLEYS. ELONGATED  
0-3 KM HODOGRAPHS AHEAD OF THE LINE WILL ALSO SUPPORT EMBEDDED  
CIRCULATIONS. THE WARM ADVECTION REGIME AND BROAD SCALE ASCENT AHEAD  
OF THE LINE MAY SUPPORT A FEW MORE DISCRETE CELLS ACROSS THE LOWER  
OH RIVER VALLEY BY MID TO LATE AFTERNOON. THIS POTENTIAL MAY BE  
CONDITIONAL ON THE DEGREE OF DESTABILIZATION THAT CAN OCCUR BEHIND  
EARLY-MORNING RAIN/WEAK THUNDERSTORMS THAT SHOULD EXIT THE REGION BY  
EARLY AFTERNOON. HOWEVER, IF DISCRETE CONVECTION CAN BECOME  
ESTABLISHED, ALL HAZARDS WILL BE POSSIBLE, INCLUDING THE POTENTIAL  
FOR LARGE HAIL AND STRONG TORNADOES.  
   
..LOWER MS RIVER VALLEY  
  
THE SURFACE COLD FRONT WILL LIKELY LAG TO THE WEST ACROSS THE  
TEXARKANA/LOWER MS VALLEY REGIONS, BUT THIS WILL ALLOW FOR SEVERAL  
HOURS OF DAYTIME HEATING BETWEEN CLOUD BREAKS AND CONTINUED  
BOUNDARY-LAYER MOISTENING AMID LOW-LEVEL THETA-E ADVECTION. WITH 7-8  
C/KM MID-LEVEL LAPSE RATES ATOP A DEEP, MOIST BOUNDARY LAYER WILL  
LIKELY SUPPORT UPWARDS OF 1500-2500 J/KG MLCAPE BY LATE AFTERNOON.  
GLANCING UPPER-LEVEL ASCENT FROM THE SYNOPTIC WAVE TO THE NORTH  
COMBINED WITH ISENTROPIC ASCENT AND LIFT ALONG ANY CONFLUENCE AXES  
AND/OR LINGERING OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION,  
SHOULD BE SUFFICIENT FOR ISOLATED TO SCATTERED THUNDERSTORMS BY MID  
TO LATE AFTERNOON. ADEQUATE DEEP-LAYER SHEAR AND STRONG FLOW IN THE  
0-3 KM LAYER WILL BE FAVORABLE FOR SUPERCELLS WITH ALL SEVERE  
HAZARDS POSSIBLE. SOME SOLUTIONS HINT AT FORECAST ESRH VALUES  
BETWEEN 300-400 M2/S2, WHICH WILL SUPPORT THE POTENTIAL FOR STRONG  
TORNADOES. THE SIGNAL FOR ISOLATED CONVECTION IS NOTABLE IN RECENT  
CAM SOLUTIONS AND IN ENSEMBLE GUIDANCE, WARRANTING AN UPGRADE TO A  
MODERATE RISK WHERE THE TORNADO POTENTIAL IS HIGHEST.   
   
..NEW YORK AND PENNSYLVANIA  
  
A WEAK UPPER-LEVEL DISTURBANCE, CURRENTLY MOVING OVER CENTRAL TX, IS  
FORECAST TO MOVE INTO THE NORTHEAST BY PEAK DAYTIME HEATING  
WEDNESDAY. A WEAK SURFACE LOW ATTENDANT TO THIS WAVE WILL FAVOR A  
RETURN TO ONSHORE FLOW WITH INCREASING BOUNDARY-LAYER MOISTURE  
THROUGH THE DAY. ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE BY  
LATE AFTERNOON AS THE WAVE MOVES ACROSS THE REGION, AND DEEP-LAYER  
SHEAR SHOULD BE SUFFICIENT TO SUPPORT A FEW STRONG TO SEVERE  
THUNDERSTORMS WITH AN ATTENDANT RISK FOR HAIL, WIND, AND POSSIBLY A  
BRIEF TORNADO.  

 

And there it is

[ClicheVortex2014]

Important little note for the lower OV/mid-MS valley... i.e., the 10% hatched tornado.

Discrete warm sector cells are possible but there's question about how much destabilization will occur. So don't be surprised if the moderate risk for tornadoes gets expanded north and possibly slightly east into SW IN/W KY if there's some stronger destabilization. This hypothetical upgrade wouldn't happen until the afternoon

 ...Mid-MS/lower OH river valleys...
   Thunderstorms are expected to develop along the cold front by the
   mid morning hours across parts of southern MO/northern AR. Mean
   storm motions along the front will favor a quick transition from
   quasi-discrete cells to more linear storm modes. Convection will
   continue to grow upscale as it approaches the mid-MS river valley
   amid increasing low-level moisture and daytime heating. Increasing
   low-level flow (up to 50-60 knots between 925-850 mb) will likely
   support bowing segments and the potential for widespread damaging
   winds. The potential for multiple 65+ knot wind reports and/or
   significant wind damage support an upgrade to a wind-driven Moderate
   risk for portions of the mid-MS/lower-OH river valleys. Elongated
   0-3 km hodographs ahead of the line will also support embedded
   circulations. The warm advection regime and broad scale ascent ahead
   of the line may support a few more discrete cells across the lower
   OH river valley by mid to late afternoon. This potential may be
   conditional on the degree of destabilization that can occur behind
   early-morning rain/weak thunderstorms that should exit the region by
   early afternoon. However, if discrete convection can become
   established, all hazards will be possible, including the potential
   for large hail and strong tornadoes.

 

Edited April 12, 2022 by ClicheVortex2014

[Central Illinois]

The hatched wind got a pretty big expansion on the north side

[Neoncyclone]

I know it's getting too close to event to use models but 17z HRRR has 3 big supercells explode off the dryline before the squall comes in. 

[Iceresistance]

Mesoscale discussion has a chance for Supercells in Northern Texas in the next 1-4 hours.

 

EDIT: Boom

Edited April 12, 2022 by Iceresistance

[ClicheVortex2014]

9 minutes ago, Neoncyclone said:

I know it's getting too close to event to use models but 17z HRRR has 3 big supercells explode off the dryline before the squall comes in. 

Fwiw, the cells near the IA/MN border are elevated. No tornado threat but probably massive hail/wind threat 

[Iceresistance]

Thunderstorm watch up for Western Texas for a Supercell south of Abilene.

[ClicheVortex2014]

1 hour ago, ClicheVortex2014 said:

Nasty supercell in N IA tonight but HRRR is hinting at some low-level stability. If that verifies, the supercell will have issues putting down a tornado. If the low-levels turn out to be even slightly unstable, there'll be a huge tornado threat.

I'm wondering if some storm-scale or local-scale processes will occur to feed the supercell warmer air than HRRR is showing. I think even 5 degrees warmer would make a significant difference.

This is what I was wondering about

 

[Iceresistance]

18z Observed soundings has DFW without a cap & OUN has a weak cap.

Edited April 12, 2022 by Iceresistance
No caps (No pun intended)

[Iceresistance]

The storm is now severe. And it's rotating.

Edited April 12, 2022 by Iceresistance

[Iceresistance]

I almost missed a Big storm in Minnesota right now.

[NebraskaEgg]

Something happening here? I assume not, judging by the lack of mention in the warning and here, though I'd like to learn why something isn't happening here if that's the case.

Edited April 12, 2022 by NebraskaEgg

[Iceresistance]

4 minutes ago, NebraskaEgg said:

Something happening here? I assume not, judging by the lack of mention in the warning and here, though I'd like to learn why something isn't happening here if that's the case.

There's Supercells to watch in Texas, may need to wait for a little bit for Iowa, Kansas, & Oklahoma.

[ClicheVortex2014]

22 minutes ago, NebraskaEgg said:

Something happening here? I assume not, judging by the lack of mention in the warning and here, though I'd like to learn why something isn't happening here if that's the case.

Where is that?

[Iceresistance]

Just had a gust close to 40

[Iceresistance]

Just now, ClicheVortex2014 said:

Where is that?

Eastern Minnesota, going to Western Wisconsin

[ClicheVortex2014]

2 minutes ago, Iceresistance said:

Eastern Minnesota, going to Western Wisconsin

Ah. That’s an elevated supercell so there’s no tornado threat since there’s a lot of low-level stability

[NebraskaEgg]

2 minutes ago, ClicheVortex2014 said:

Where is that?

Not quite there anymore, but around 2:26 CDT on the KMPX radar, in the warned storm to the southeast.

[ElectricStorm]

Quote

Mesoscale Discussion 0457
   NWS Storm Prediction Center Norman OK
   0248 PM CDT Tue Apr 12 2022

   Areas affected...northeast NE...southeast SD...extreme southwest MN
   and northwest IA

   Concerning...Severe potential...Tornado Watch likely 

   Valid 121948Z - 122115Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Convective initiation is expected by around 21-23z. A
   tornado watch will likely be needed in the next hour or so. Severe
   thunderstorms capable of large hail, damaging gusts and a few
   tornadoes are possible.

   DISCUSSION...A surface low is located near the central NE/SD border
   as of 19z. A warm front was noted in surface analysis arcing from
   the low across northeast NE into southern IA. Meanwhile, the surface
   cold front was located across central NE and rapidly approaching the
   surface dryline just a few counties to the east. Increasing cumulus
   has been noted in visible satellite imagery along the dryline and
   across the warm sector to the east across northeast NE. The cumulus
   along the dryline has shown modest vertical development where
   capping is likely less than further east. As the warm front
   continues to lift northward and better quality boundary-layer
   moisture works northward in conjunction with strong large-scale
   ascent, convection is expected to develop near the triple point by
   21-23z. 

   Initial convection across southeast SD into southwest MN to near the
   NE/IA border may be elevated near/just to the cold side of the warm
   front, with a better-quality warm sector remaining quite narrow from
   near the MO River into northwest IA. Fast storm motion toward the
   northeast could result in these storms rapidly moving away from the
   better warm sector as they mature. Nevertheless, strong vertical
   shear, steepening midlevel lapse rates and sufficient instability
   should support organized supercells capable of large hail and
   perhaps strong gusts. Any storm that develops in the better warm
   sector or that can anchor to the warm front will access better
   low-level shear and see an increased risk for tornado development.
   Furthermore, any storm that develops further south along the cold
   front/dryline in NE may be higher-based, posing a threat for large
   hail and damaging gusts. If any dryline convection persists eastward
   into better moisture, these cells also could become surface-based
   within the better-quality warm sector with a corresponding increase
   in tornado potential. With time into the evening, more linear
   convective development is expected near/east of the MO River as the
   cold front surges east.

   ..Leitman/Thompson.. 04/12/2022

 

 

Edited April 12, 2022 by OKwx_2001