May 29th - June 3rd?, 2022 | Severe Weather

[Neoncyclone]

https://www.spc.noaa.gov/products/md/md0958.html 

Pretty gnarly mid-level lapse rates this morning in C IA

[Ingyball]

I'm not nearly as confident for Tuesday as SPC is. We lose the upper flow and it look like we will be dealing with linear convection along the cold front instead of discrete cell. Shear overall looks marginal right now. Flooding over parts of south-central and southeast Kansas may end up being the greatest concern. 

[ElectricStorm]

Wednesday is looking solid for my area now with the Day 4 slight risk up. Could be a good way to start June 

[ClicheVortex2014]

 

[ElectricStorm]

Monday is looking like it could be a pretty big tornado event. Parameters are looking pretty dang nasty...

[ElectricStorm]

Yep... 15 hatched tornado area added for tomorrow 

[ClicheVortex2014]

There's the day 2 moderate. Really thought it would've been for damaging winds at first, but nope. Tornadoes.

Talk of 2000+ mlcape/70+ knots effective shear(!!!!) and long-track/intense tornadoes. YIKES.

DAY 2 CONVECTIVE OUTLOOK    
NWS STORM PREDICTION CENTER NORMAN OK  
1229 PM CDT SUN MAY 29 2022  
  
VALID 301200Z - 311200Z  
  
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS  
OF WESTERN MINNESOTA...FAR NORTHEAST SOUTH DAKOTA...AND FAR  
SOUTHEAST NORTH DAKOTA....  
   
..SUMMARY  
  
NUMEROUS SEVERE THUNDERSTORMS ARE FORECAST ACROSS PARTS OF THE UPPER  
MIDWEST WITH SCATTERED SEVERE STORMS SOUTHWARD INTO THE CENTRAL  
GREAT PLAINS ON MONDAY AND MONDAY NIGHT.  LARGE TO GIANT HAIL, 60-80  
MPH GUSTS, AND SEVERAL TORNADOES ARE PROBABLE, INCLUDING THE  
POSSIBILITY FOR A COUPLE OF INTENSE LONG-TRACK TORNADOES OVER PARTS  
OF THE UPPER MIDWEST.  
   
..SYNOPSIS  
  
A STRONG MID-LEVEL JET STREAK WILL ROUND THE BASE OF THE LARGER  
SCALE TROUGH ACROSS THE WESTERN CONUS AND STRENGTHEN TO NEAR 100  
KNOTS AS THE UPPER-LEVEL LOW AMPLIFIES ACROSS THE NORTHERN PLAINS.  
MEANWHILE, A SURFACE LOW WILL DEEPEN AS IT MOVES FROM THE CENTRAL  
PLAINS INTO THE UPPER MIDWEST. AS THIS OCCURS, LOW-LEVEL FLOW WILL  
STRENGTHEN AND THE COLD FRONT WILL SHARPEN ACROSS EASTERN  
NEBRASKA/SOUTHEAST SOUTH DAKOTA AS IT MOVES NORTHEASTWARD.   
   
..UPPER MIDWEST  
  
SEVERAL CLUSTERS OF THUNDERSTORMS WILL LIKELY BE ONGOING AT THE  
BEGINNING OF THE PERIOD ACROSS EASTERN SOUTH DAKOTA/MINNESOTA. THIS  
WILL LIKELY HAVE SOME IMPLICATIONS ON THE LOCATION OF THE GREATEST  
SEVERE WEATHER THREAT DURING THE AFTERNOON/EVENING, WITH HINTS OF  
REMNANT OUTFLOW BOUNDARIES IN SOME 12Z CAM GUIDANCE. REGARDLESS OF  
MORNING CONVECTIVE COVERAGE, SIGNIFICANT MASS RESPONSE ASSOCIATED  
WITH THE DEEPENING SURFACE LOW SHOULD SUPPORT AIRMASS RECOVERY  
ACROSS A MAJORITY OF THE WARM SECTOR. IN FACT, RAP FORECAST  
SOUNDINGS INDICATE TEMPERATURES ONLY NEED TO WARM INTO THE MID 70S  
TO ERODE INHIBITION NEAR THE SURFACE LOW AND UPPER 70S FARTHER EAST  
IN THE WARM SECTOR. THIS COULD HAPPEN AS EARLY AS 15-16Z ACROSS  
SOUTHEAST SOUTH DAKOTA IN A STRONGLY SHEARED WIND PROFILE SUPPORTIVE  
OF SUPERCELLS AND ALL SEVERE WEATHER HAZARDS.   
  
STRONG INSTABILITY IS EXPECTED ACROSS CENTRAL/WESTERN MINNESOTA  
WHERE THE HREF MEAN MLCAPE EXCEEDS 2000 J/KG ACROSS A BROAD REGION  
WHERE EFFECTIVE SHEAR WILL BE IN EXCESS OF 70 KNOTS. THEREFORE,  
NUMEROUS SUPERCELLS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF THE  
COLD FRONT AS IT MOVES NORTHEASTWARD THROUGH THE AFTERNOON. SURFACE  
WINDS ARE FORECAST TO REMAIN SOUTHEASTERLY EAST/NORTHEAST OF THE  
SURFACE LOW AS IT DEEPENS THROUGH THE AFTERNOON. THESE BACKED  
SURFACE WINDS COMBINED WITH A 35-40 KNOT LOW-LEVEL JET  
(STRENGTHENING TO 50 KNOTS BY 00Z) WILL PROVIDE AMPLE LOW-LEVEL  
SHEAR SUPPORTIVE OF STRONG TORNADOES. ADDITIONALLY, THE DEEP-LAYER  
SHEAR VECTOR ORIENTATION WILL SUPPORT DISCRETE OR SEMI-DISCRETE  
STORM MODE WHICH WILL ALSO INCREASE TORNADO POTENTIAL. THERE MAY BE  
TOO MUCH FORCING AND STORM INTERACTION ACROSS EASTERN SOUTH DAKOTA  
AND NORTH DAKOTA WHICH COULD HAVE A DETRIMENTAL IMPACT ON TORNADO  
POTENTIAL, BUT A MORE DISCRETE MODE IS EXPECTED WITH EASTWARD  
EXPANSE. THEREFORE, A MODERATE RISK HAS BEEN ADDED FOR THE REGION  
WHICH IS MOST LIKELY TO HAVE THE GREATEST STORM COVERAGE THAT  
REMAINS DISCRETE ENOUGH FOR A SIGNIFICANT TORNADO THREAT. THE  
AMBIENT ENVIRONMENT (2000+ J/KG MLCAPE) AND 70+ KNOTS OF EFFECTIVE  
SHEAR WITH STRONG LOW-LEVEL SHEAR COULD SUPPORT LONG-LIVED/INTENSE  
TORNADOES WITH ANY SUPERCELLS WHICH CAN REMAIN DISCRETE FOR AN  
EXTENDED PERIOD OF TIME.   
   
..CENTRAL PLAINS  
  
FARTHER SOUTH ALONG THE FRONT, MORE ISOLATED THUNDERSTORM  
DEVELOPMENT IS EXPECTED WITH MORE VEERED LOW-LEVEL FLOW. ENOUGH  
MID-LEVEL FLOW IS EXPECTED TO OVERLAP THE WARM SECTOR TO PROVIDE  
AMPLE SHEAR FOR STORM ORGANIZATION IN A VERY UNSTABLE ENVIRONMENT.  
THEREFORE, SUPERCELLS WILL BE THE PRIMARY STORM MODE WITH ANY  
DEVELOPMENT ALONG THE FRONT.   
  
ISOLATED TO SCATTERED CONVECTION IS ANTICIPATED ACROSS PORTIONS OF  
IOWA/EASTERN NEBRASKA AND POTENTIALLY INTO NORTHEAST KANSAS WITH A  
MORE CONDITIONAL THREAT TO THE SOUTH. CAM GUIDANCE TRIES TO HINT AT  
SOME CONVECTIVE ATTEMPTS ALONG THE DRYLINE AS FAR SOUTH AS I-40 IN  
OKLAHOMA, BUT RISING HEIGHTS AND WARM MID-LEVEL TEMPERATURES WILL  
LIKELY LIMIT STORM POTENTIAL THAT FAR SOUTH. HOWEVER, AN ISOLATED  
THREAT PERSISTS INTO SOUTHERN KANSAS AND PERHAPS NORTHERN OKLAHOMA.  

 

Edited May 29, 2022 by ClicheVortex2014

[ClicheVortex2014]

This kind of sounding is something I'd expect in the cool season. Very strong low-level instability. Steep lapse rates all the way through 6km. It really is more of an early spring/late fall event with the strength of the winds and strong negative tilt.

Storm mode obviously an issue, but SPC does have good reason to believe semi-discrete/discrete cells will likely verify somewhere.

Edited May 29, 2022 by ClicheVortex2014

[ClicheVortex2014]

Full run (edit: through the bulk of the event at least)

 

Edited May 29, 2022 by ClicheVortex2014

[ClicheVortex2014]

A lot of overlap between the high-end derecho earlier this month and the areas facing significant winds tonight

Edited May 29, 2022 by ClicheVortex2014

[ClicheVortex2014]

Watches coming

[snowlover2]

Here's the first watch.

Quote

URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 287
   NWS Storm Prediction Center Norman OK
   335 PM CDT Sun May 29 2022

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     Northwestern Minnesota
     Eastern North Dakota

   * Effective this Sunday afternoon and evening from 335 PM until
     1000 PM CDT.

   * Primary threats include...
     Scattered large hail and isolated very large hail events to 2
       inches in diameter possible
     Scattered damaging wind gusts to 70 mph possible
     A tornado or two possible

   SUMMARY...Scattered thunderstorm development is expected along a
   roughly north-south band near the North Dakota-Minnesota border this
   afternoon, while additional storms could form later this afternoon
   into northeastern North Dakota.  The storm environment will support
   a mix of multicell clusters and some supercells, with the primary
   threats of occasional large hail and damaging outflow gusts.  A
   tornado or two may occur with any mature supercells interacting with
   the surface warm front.

   The severe thunderstorm watch area is approximately along and 60
   statute miles east and west of a line from 20 miles west northwest
   of Roseau MN to 60 miles south of Detroit Lakes MN. For a complete
   depiction of the watch see the associated watch outline update
   (WOUS64 KWNS WOU7).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Severe Thunderstorm Watch means conditions are
   favorable for severe thunderstorms in and close to the watch area.
   Persons in these areas should be on the lookout for threatening
   weather conditions and listen for later statements and possible
   warnings. Severe thunderstorms can and occasionally do produce
   tornadoes.

   &&

   AVIATION...A few severe thunderstorms with hail surface and aloft to
   2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
   few cumulonimbi with maximum tops to 500. Mean storm motion vector
   21025.

   ...Thompson

 

 

[ClicheVortex2014]

MPX is sounding the alarms (so-to-speak for now), as they should

National Weather Service Twin Cities/Chanhassen MN
319 PM CDT Sun May 29 2022

.DISCUSSION...(This evening through Sunday)
Issued at 317 PM CDT Sun May 29 2022

KEY MESSAGES:

...TORNADO OUTBREAK POSSIBLE MONDAY AFTERNOON IN WESTERN MINNESOTA...

- Multiple rounds of severe weather possible this evening into
Monday morning. Strong winds and large hail will be the main
threats, with a small tornado risk existing when storms first
develop early in the evening.

- Tornado outbreak possible Monday afternoon in western MN. Line of
strong to severe storms likely to impact eastern MN into western WI
late Monday afternoon through the evening.

- Much quieter with near normal temperatures Tuesday through next
weekend.

Today through Monday morning... The atmosphere has been quickly
recharging in the wake of this mornings activity, with SPC
mesoanalysis already showing 2000-4000 j/kg of MUCAPE along the
MN/Dakotas border, though this is strongly capped. The big question
this period is when do we start tapping into that instability.
Between the cold front over eastern SD, multiple shortwaves rippling
through the southwesterly jet streak overhead, and a strengthening
LLJ, we`ll have ample potential sources to get storms, but there`s
still a good deal of spread on where storms may develop this
evening. However, once storms do get going, we may not get much of a
rest in the MPX area until mid-Monday morning. Given the instability
(2000-3000 j/kg of muCAPE), strong shear (50 kts of 0-6km shear),
and steep mid-level lapse rates, the risk for organized severe
storms, including supercells exists. Another complicating factor is
that we`ll likely see storms develop this evening on the western
edge of the LLJ over MN, but we also have the possibility of seeing
an MCS come out of Nebraska and head into western MN. So there`s
potential for a rather busy 12 hours, if we can force storms through
the capping.

Monday... Confidence continues to increase in a severe weather
outbreak in MN for Memorial Day, with a tornado outbreak possible in
western MN, where the SPC upgraded the Day 2 convective outlook to a
Moderate risk. We look to have two zones of concern for severe
weather. One in western MN closer to the surface low that will be
deepening as it lifts north across eastern SD. The other risk area
will be from roughly a New Ulm to Little Falls line into western WI,
where a line of thunderstorms look likely to develop between 5pm and
7pm.

For western MN, an environment ripe for supercells looks to exist by
the early afternoon. HREF shows several strong, long track Updraft
Helicity tracks across the eastern Dakotas/western MN, indicative of
a risk for long track supercells. The main uncertainty for western
MN is the forcing looks to result in widespread thunderstorm
development, which means lots of cell mergers and other interactions
going on that could be either destructive or constructive, but
that`s something we won`t get a handle on until we`re basically into
the warning phase. As SPC mentions in their Day 2 convective
outlook, the synoptic environment in place will be one favorable for
the development of some potentially destructive and long track
tornadoes depending on how cell interactions and the such work out.

For eastern MN, the CAMs are all in pretty good agreement with a
line of storms developing along an advancing cold front between 5
and 7 pm. The instability/shear parameter space for this area will
also favor supercells. However, the CAMs are showing the primary
storm mode for eastern MN being linear, so the tornado threat does
not look as great as in western MN, but is still present for any
storms we see along the line, along with the attendant risk for
strong winds and large hail. These storms will be on a weakening
trend as they move into western WI and encounter an environment with
less instability.

 

[ClicheVortex2014]

Explosive development in northern Minnesota

 

 

Edited May 29, 2022 by ClicheVortex2014

[snowlover2]

Other watch is up now leaving the enhanced area waiting their turn.

Quote

  URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 288
   NWS Storm Prediction Center Norman OK
   305 PM MDT Sun May 29 2022

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     Western Nebraska

   * Effective this Sunday afternoon and evening from 305 PM until
     900 PM MDT.

   * Primary threats include...
     Scattered damaging wind gusts to 70 mph likely
     Scattered large hail events to 1.5 inches in diameter likely

   SUMMARY...High-based thunderstorms will move eastward into western
   Nebraska this afternoon through late evening.  The storms should
   strengthen in time, with the potential to produce severe outflow
   gusts up to 70 mph, and occasional large hail to 1.5 inches in
   diameter.

   The severe thunderstorm watch area is approximately along and 65
   statute miles north and south of a line from 30 miles west of
   Alliance NE to 35 miles east of Mullen NE. For a complete depiction
   of the watch see the associated watch outline update (WOUS64 KWNS
   WOU8).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Severe Thunderstorm Watch means conditions are
   favorable for severe thunderstorms in and close to the watch area.
   Persons in these areas should be on the lookout for threatening
   weather conditions and listen for later statements and possible
   warnings. Severe thunderstorms can and occasionally do produce
   tornadoes.

   &&

   OTHER WATCH INFORMATION...CONTINUE...WW 287...

   AVIATION...A few severe thunderstorms with hail surface and aloft to
   1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
   few cumulonimbi with maximum tops to 500. Mean storm motion vector
   26035.

   ...Thompson

 

 

[ClicheVortex2014]

1 minute ago, snowlover2 said:

Other watch is up now leaving the enhanced area waiting their turn.

 

Here we go

Edited May 29, 2022 by ClicheVortex2014

[ClicheVortex2014]

I was expecting something like this persistent/consistent western troughing because of the sustained moderate Nina/-PDO, but wow. It's been non-stop since November with exception to January and some of February. 

Only thing about the pattern this month is that the troughs just didn't take a favorable tilt. That really killed the high-end event potential. But now, obviously, we're about to have as favorable of a tilt as you can have. That trough is gonna be crazy tomorrow.

Edited May 29, 2022 by ClicheVortex2014

[ClicheVortex2014]

The leading warning for the squall in Nebraska is for 70 mph winds. Starting to ramp up. Nocturnal LLJ will kick in in a couple hours. Tornado threat will develop in the enhanced risk around then, as well.

[ClicheVortex2014]

   Mesoscale Discussion 0965
   NWS Storm Prediction Center Norman OK
   0549 PM CDT Sun May 29 2022

   Areas affected...portions of central and eastern Nebraska...far
   north-central kansas and extreme southeastern South Dakota.

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

   Valid 292249Z - 300015Z

   Probability of Watch Issuance...80 percent

   SUMMARY...A complex convective scenario currently unfolding across
   the central Plains will likely result in scattered severe storm
   coverage in the next couple of hours. Supercells capable of all
   hazards are possible necessitating a Tornado Watch in the next hour.

   DISCUSSION...Ahead of a well developed shortwave trough over the
   western and central Rockies visible on regional satellite imagery,
   surface observations show clearing skies and warming temperatures
   along the western edge of a cirrostartus deck across portions of
   central NE. Roughly correlated with the position of a weakening
   surface cold front also evident across the central Plains, further
   heating of the modified post frontal airmass, and lift from the
   approaching trough should help initiate convection late this
   afternoon into early this evening.

   Initial cumulus towers on visible imagery suggest MLCINH is quickly
   eroding across portions of central NE along the western edge of the
   higher cloud deck. This is matched by SPC mesoanalyis which shows
   1500-2500 J/kg of MLCAPE has developed owing to surface T/TDs in the
   mid 80s and low 50s F respectively. Regional VAD VWPs favor a
   supercellular storm mode with 40-50 kt of effective shear. The
   substantial buoyancy and vertical shear should easily support a hail
   and wind risk initially. The tornado threat is more uncertain, but
   while storms will be high-based/elevated initially. Deeper moisture
   (mid 60s F surface dewpoints) pooled along the front and sheltered
   by the high clouds from deeper mixing should result in lower
   LCL/low-level mesocyclone development farther east.  The enhanced
   backed flow along and east of the front into eastern NE would favor
   a greater tornado threat with any discrete supercells.

   A secondary severe regime may also develop along the dryline/triple
   point across far northern KS and south-central NE. Here very warm
   temperatures (90-100 F) are working to erode remaining MLCINH in a
   moistening environment along a corridor of very steep low and
   mid-level lapse rates of 8-9 C/km. Along the southern fringes of the
   dynamic ascent from the approaching shortwave, it remains unclear if
   and how many storms may develop this afternoon/evening. However,
   should storms develop and move into southeastern NE and far
   northeastern KS, 2000-2500 J/kg of MLCAPE and 40-50 kt of effective
   shear would favor isolated supercells capable of all hazards. Latest
   WOFS guidance does depict a couple storm with strong UH indicating a
   conditional dryline threat this evening.

   While uncertainty in both scenarios is considerable owing to the
   complex arrangement of surface boundaries and cloud cover. It
   appears likely that the severe threat will increase over the next
   couple of hours. A tornado watch will likely be needed for portions
   of the central Plains this evening.

 

[ClicheVortex2014]

Good time for RAP and HRRR to stop loading. At least RAP has recently resumed but RAP is washed. 

Hopefully HRRR comes back before 0z runs start.

[ClicheVortex2014]

Interesting supercell motion in Nebraska. Almost like it’s getting drawn into the squall but it’s not.

Satellite shows cumulus are growing further east in Nebraska… next round should start soon

[ClicheVortex2014]

Damaging wind threat increasing

   Mesoscale Discussion 0966
   NWS Storm Prediction Center Norman OK
   0659 PM CDT Sun May 29 2022

   Areas affected...western Nebraska

   Concerning...Severe Thunderstorm Watch 288...

   Valid 292359Z - 300100Z

   The severe weather threat for Severe Thunderstorm Watch 288
   continues.

   SUMMARY...Several clusters of storms with a damaging wind and hail
   risk should continue eastward this evening.

   DISCUSSION...As of 2350z, regional radar imagery showed a cluster of
   severe storms ongoing across portions of the western NE Panhandle.
   Recent obs of M56 kt at Chadron, NE and several other damaging wind
   reports have been received over the last hour as the initially
   high-based storms have tracked eastward out of eastern WY. Damaging
   wind gusts should continue with the mostly linear storm complex as
   it move eastward toward western/central NE. Moisture advection
   within the post front airmass ahead of the ongoing cluster should
   also result in gradual increase in hail potential along with the
   continued threat for damaging wind gusts as more buoyant conditions
   are encountered. 

   A supercell or two may also evolve along the southern flanks of the
   ongoing convection within the warmer and drier airmass across
   southwestern NE. While confidence is low, more moist/buoyant
   condition to the east would also favor a hail and wind threat with
   any storms able to become established.

 

[snowlover2]

Tornado watch up.

Quote

 URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 289
   NWS Storm Prediction Center Norman OK
   715 PM CDT Sun May 29 2022

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Central and Eastern Nebraska
     Southeast South Dakota

   * Effective this Sunday night and Monday morning from 715 PM
     until 200 AM CDT.

   * Primary threats include...
     A few tornadoes possible
     Scattered damaging winds likely with isolated significant gusts
       to 80 mph possible
     Scattered large hail likely with isolated very large hail events
       to 3 inches in diameter possible

   SUMMARY...Severe storms are expected to develop and increase across
   the region, initially across central/north-central Nebraska and
   eventually into southeast South Dakota and northeast Nebraska. A
   somewhat separate corridor of severe thunderstorm development is
   possible farther to the southeast across south-central/east-central
   Nebraska this evening. Initial supercells are likely, and a
   well-organized cluster of storms may also evolve and accelerate
   northeastward this evening. All aspects of severe weather are
   possible including very large hail, damaging winds, and a few
   tornadoes.

   The tornado watch area is approximately along and 105 statute miles
   north and south of a line from 30 miles west northwest of Broken Bow
   NE to 40 miles east southeast of Yankton SD. For a complete
   depiction of the watch see the associated watch outline update
   (WOUS64 KWNS WOU9).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Tornado Watch means conditions are favorable for
   tornadoes and severe thunderstorms in and close to the watch
   area. Persons in these areas should be on the lookout for
   threatening weather conditions and listen for later statements
   and possible warnings.

   &&

   OTHER WATCH INFORMATION...CONTINUE...WW 287...WW 288...

   AVIATION...Tornadoes and a few severe thunderstorms with hail
   surface and aloft to 3 inches. Extreme turbulence and surface wind
   gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean
   storm motion vector 24030.

   ...Guyer

 

 

[ClicheVortex2014]

OAX is just about ready for tornadic storms. Especially areas upstream (northwest) of there.

[ClicheVortex2014]

Nice EML over SW OH today.

Edited May 30, 2022 by ClicheVortex2014