2018 Short to Medium Range Severe Thread

[RCNYILWX]

Certainly wouldn't rule out slight risk verifying for elevated hailers with strong effective shear and sufficient mucape but my perception is that it's fairly rare to get a slight risk worthy elevated hailer event around here.

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[hawkeye_wx]

Getting missed north and south has been the theme so far this month around here.  This morning's storms mostly missed south.  I got a quarter inch of rain.

[snowlover2]

Latest day 1 shifted the slight risk south some in IN/OH. Basically centered along I-70.

 

Quote

Day 1 Convective Outlook 
   NWS Storm Prediction Center Norman OK
   1128 AM CDT Sat May 12 2018

   Valid 121630Z - 131200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PARTS OF
   MID-ATLANTIC STATES...

   ...SUMMARY...
   Scattered severe storms with damaging winds as the primary hazard
   are most likely across portions of the Upper Ohio Valley to the
   Mid-Atlantic Coast in the late afternoon and evening.

   ...Corn Belt to Mid-Atlantic Coast...
   A pair of MCVs in conjunction with a strong baroclinic zone will be
   the primary drivers of severe storm development expected to begin in
   the late afternoon. While the overall synoptic pattern is more
   typical of mid-late June, boundary-layer moisture is not of
   summertime quality and will likely mitigate a greater severe weather
   threat. 12Z NAM soundings appear to have the typical moist bias in
   increasing mean-mixing ratios well above other guidance such as the
   RAP, which results in overdone buoyancy profiles at peak heating.

   Primary severe focus is expected to develop downstream of the
   remnant MCV currently near the MI/OH/IN border region. Robust
   diabatic heating south of the surface front that lies from central
   OH to PA should result in scattered storm development late afternoon
   from east-central OH across southern PA. The eastern extent of
   frontal placement near the Mid-Atlantic Coast has lower confidence
   given an extensive stratus deck that is only slowing eroding across
   eastern PA and most of NJ. Most CAM guidance appears to have trended
   southward with simulated storms in this region. Baroclinicity will
   be most pronounced along this portion of the front, in conjunction
   with enlarged low-level hodographs. This should yield a confined
   risk for a discrete supercell or two with an associated tornado
   threat. Otherwise, an initial large hail threat is anticipated on
   the eastern periphery of the expansive EML. This should transition
   to primarily a strong to isolated severe wind gust risk as storms
   evolve into clusters and line segments amid nearly unidirectional
   deep-layer wind profiles. These hazards will likely persist through
   much of the evening until storms move off the coast and weaken with
   diminishing nocturnal instability.

   Farther west, an MCV near the MO/IA/IL border should translate east
   and likely cross the surface front across parts of central IL/IN
   later this afternoon. Most CAMs are not that suggestive of
   convection intensifying in this region, although a few indicate
   potential for a strengthening cluster. CAPE/shear will be sufficient
   for potential intensification and have adjusted south MRGL/SLGT risk
   probabilities for hail/wind hazards.

   Low-level warm advection will again increase across IA into northern
   IL/IN tonight with widespread elevated storms well north of the
   surface front. This activity will quickly evolve into clusters with
   embedded isolated marginally severe hail risk in the strongest
   updrafts.

   

   ..Grams/Marsh.. 05/12/2018

 

[IllinoisWedges]

Looks like daily potential for severe storms will continue. MCS tomorrow night running through 1-3k MUCAPE. Next day looks like a typical summer day with a potential MCS at night with the lingering SBCAPE. Shades of July. 

[Chicago Storm]

As expected, tonight is not slight worthy.

 

Tomorrow night and Monday look much more interesting.

[HillsdaleMIWeather]

Models are slowly pushing the instability further and further north Monday 

[snowlover2]

Slight risk added to EC IN/good chunk of Ohio for tomorrow on latest day 2. Slight risk for parts of IA/MO/IL also.

Quote

Day 2 Convective Outlook 
   NWS Storm Prediction Center Norman OK
   1228 PM CDT Sun May 13 2018

   Valid 141200Z - 151200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE
   SOUTHERN PLAINS TO THE MID MS VALLEY AND ACROSS PARTS OF THE OHIO
   VALLEY...

   ...SUMMARY...
   Severe thunderstorms, capable of damaging winds and large hail, will
   be possible Monday afternoon and evening from parts of the southern
   Plains northeastward to the mid Mississippi Valley. Elsewhere, a few
   severe storms will be possible from the mid/upper Ohio Valley
   eastward to the Mid-Atlantic. The main threat with these cells will
   be damaging wind.

   ...Southern Plains to the mid Mississippi Valley...
   Severe/convective evolution appears somewhat uncertain across
   portions of the region on Monday. Within a regime of approximately
   25-40 kt 500mb southwesterlies overlying the southern Plains and
   Missouri Valley, several weak/convectively augmented impulses will
   likely be transiting northeastward through the day. Focused
   ascent/warm advection ahead of each of these impulses will likely
   encourage convective initiation along both a dry line extending
   southward from southern Kansas into western Oklahoma/Texas, as well
   as a front extending to the northeast towards the Kansas City metro
   area and points east/northeast. The strongest flow aloft (and
   potential for greatest storm organization) will likely exist from
   northeast Kansas to the mid Mississippi Valley. Furthermore, a nose
   of focused warm advection will likely be placed in this zone as
   well, such that scattered convection is expected by afternoon. In
   turn, steep mid-level lapse rates (giving rise to moderate/strong
   buoyancy) should yield a few multicell clusters, with embedded
   supercell elements, primarily capable of damaging winds and large
   hail near/south of the front. To its north, large hail will be the
   primary threat.

   With south/southwestward extent, decreasing flow aloft will likely
   reduce storm organization. Nonetheless, favorable heating/lapse
   rates should encourage a damaging wind threat with any deeper cores
   during the afternoon/evening.

   ...Ohio Valley to the Mid Atlantic...
   Considerable uncertainty also exists across this region on Monday.
   It is likely that some residual convective system will be ongoing
   across parts of Indiana and Ohio Monday morning, resulting from
   overnight convection generating in northern Illinois. With the Ohio
   Valley remaining on the edge of a plume of steep mid-level lapse
   rates, any stronger surface-based convection will likely be capable
   of damaging winds. Additionally, related to this convective system,
   a mid-level speed maximum will be transiting the Midwest through the
   morning/mid-day hours, which should assist some with convective
   system maintenance and downward momentum transport.

   Uncertainty remains in that there is some spatial offset between the
   zone of greatest destabilization (due to timing of the
   wave/potential MCS) over the Mid-Atlantic and corridor of better
   mid-level flow over the Midwest. A slight risk has been introduced
   across the mid/upper Ohio Valley, where the highest confidence
   exists in the potential for an ongoing convective system, capable of
   damaging winds, during the first half of the day. Farther southeast,
   a decrease in mid-level flow/expected organization, as well as
   greater uncertainty with downstream convective development,
   precludes an upgrade at this time. However, if confidence in a more
   robust, east/southeastward propagating system increases, the slight
   risk may be expanded southeast accordingly.

   ...MAXIMUM RISK BY HAZARD...
   Tornado:   2%     - Marginal
   Wind:     15%     - Slight
   Hail:     15%     - Slight

   ..Picca.. 05/13/2018

 

 

[Hoosier]

Sky looking fairly dark to the south, so I checked radar and discovered there is a nice little bow that is warned about 35 miles away.

[CoalCityWxMan]

11 minutes ago, Hoosier said:

Sky looking fairly dark to the south, so I checked radar and discovered there is a nice little bow that is warned about 35 miles away.

Produced a lot of marginally severe hail from central Iowa through Illinois. Surprised with how well it’s held together 

[CheeselandSkies]

Interesting that E. IA/N. IL/S. WI are in the SPC 70% area for thunderstorms from 04Z-12Z tonight, but area radars are completely quiet at the moment.

[Harry Perry]

12 minutes ago, CheeselandSkies said:

Interesting that E. IA/N. IL/S. WI are in the SPC 70% area for thunderstorms from 04Z-12Z tonight, but area radars are completely quiet at the moment.

Majority of short range guidance shows covective development along the front by roughly 06z. Interesting note, that same guidance is still thinking there are storms ongoing in north central Indiana at the current hour and there is nothing - so this should be an interesting night lol. 

[Harry Perry]

Wouldn’t be surprised to see the slight risk expanded farther north for Monday evening, especially if instability builds. 

[Hoosier]

This outlook is bananas

[Stebo]

7 minutes ago, Hoosier said:

This outlook is bananas

All boils down to timing, right now the area from Chicago into MI/IN/NW OH look prime on short term models this afternoon with a wave coming out of the plains, also a warm frontal boundary lifts northward through the day.

[nwohweather]

It’ll be interesting where the outflow boundary gets laid down this morning. Might get some decent winds today as the disturbance moves east combining with a fairly unstable environment

[Hoosier]

8 hours ago, Stebo said:

All boils down to timing, right now the area from Chicago into MI/IN/NW OH look prime on short term models this afternoon with a wave coming out of the plains, also a warm frontal boundary lifts northward through the day.

I mean it looks like a banana.  

Had some non severe hail here earlier this morning.  

[Chicago Storm]

Decent CAPE/DP/Lapse Rates/Shear combo today, which should lead to scattered severe storms this afternoon/evening. Few OFB's around from overnight/morning activity as well.

[beavis1729]

54 minutes ago, Chicago Storm said:

Decent CAPE/DP/Lapse Rates/Shear combo today, which should lead to scattered severe storms this afternoon/evening. Few OFB's around form overnight/morning activity as well.

Severe T-storm Watch just issued for much of IL and MO.  ORD is at 81/61...a nice recovery from the rain earlier.  PIA is 89/68.

 

[snowlover2]

Pretty nice looking bow echo moving just north of St. Louis.

[geddyweather]

81/70/70 here. What a pity if we can't get anything to fire bc these are the juiciest numbers I've seen in quite awhile. Think I only got remotely close to this once last summer, not sure about further in the past.

Clusters in IL/MO doing well so there may be some hope, but it will all be post-sunset.

[Powerball]

17 hours ago, Hoosier said:

This outlook is bananas

[Chicago Storm]

There really wasn't any tor potential today...But I ended up drifting west for the heck of it this afternoon, and ended up on the supercell that moved near DKB. Encountered a lowering, though not much rotation. It did have some mid-level rotation at the time per radar though. Also picked up some dime size hail.

[snowlover2]

38 minutes ago, Chicago Storm said:

There really wasn't any tor potential today...But I ended up drifting west for the heck of it this afternoon, and ended up on the supercell that moved near DKB. Encountered a lowering, though not much rotation. It did have some mid-level rotation at the time per radar though. Also picked up some dime size hail.

Wow awesome pics.

[kevlon62]

There really wasn't any tor potential today...But I ended up drifting west for the heck of it this afternoon, and ended up on the supercell that moved near DKB. Encountered a lowering, though not much rotation. It did have some mid-level rotation at the time per radar though. Also picked up some dime size hail.

Great shots.

Nice stretch of decent action going lately. I was headed home just south of that Washington County, WI EF-0 last week and sat in suburban MKE traffic with a few hail cores passing through.

Tonight we were at the high school track as a cell popped just southwest and moved overhead before we made it to the cars. Good thunder and rain now for almost the past hour.

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[Benadrill]

**** tier storms all week

[NTXYankee]

At this point I will be happy with a rain shower that lasts more than a minute for the sake of my lawn.  Haven’t had anything in my part of Columbus during this whole stalled front scenario.

[snowlover2]

Tornado warning now for Columbus Ohio. Over Ohio State currently.

Quote

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Wilmington OH
600 PM EDT TUE MAY 15 2018

The National Weather Service in Wilmington has issued a

* Tornado Warning for...
  Central Franklin County in central Ohio...
  Northwestern Fairfield County in central Ohio...

* Until 630 PM EDT.

* At 559 PM EDT, a severe thunderstorm capable of producing a tornado
  was located near Ohio State University, moving east at 35 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without
           shelter. Mobile homes will be damaged or destroyed.
           Damage to roofs, windows, and vehicles will occur.  Tree
           damage is likely.

* Locations impacted include...
  Columbus, Reynoldsburg, Grove City, Upper Arlington, Gahanna,
  Hilliard, Pickerington, Bexley, Canal Winchester, Groveport, Ohio
  State University, Whitehall, Grandview Heights, Obetz, Lithopolis,
  Urbancrest, Valleyview, Marble Cliff, Brice and Port Columbus
  Airport.

This includes the following Interstates...
I-70 in Ohio between mile markers 91 and 112.
I-71 in Ohio between mile markers 102 and 114.

 

[geddyweather]

On 5/14/2018 at 7:36 PM, geddyweather said:

81/70/70 here. What a pity if we can't get anything to fire bc these are the juiciest numbers I've seen in quite awhile. Think I only got remotely close to this once last summer, not sure about further in the past.

Clusters in IL/MO doing well so there may be some hope, but it will all be post-sunset.

Well, this ended up verifying quite nicely. 81/70/70 played quite a roll in the development of a cluster of storms over NE IN and NW OH last (Monday) night. This cluster evolved into a string of supercells with some intense updrafts which, soaking in the residual heat and moisture, produced ping-pong to golf ball sized hail. All of this happened after 10pm and really ramped up after the 11pm hour, with multiple storms producing hail and intense lightning. 

The storm of the night was by far located near Kendallville, IN. This cell roared eastbound across nrn IN and into NW OH, having evolved from an initial cluster near South Bend. At it's peak, it was warned multiple times for golfball sized hail from Kendallville all the way to the Bryan, OH area. A snap of it's core revealed the intense nature of the storm as it crossed I-69 near Auburn. (1)

Runner-up storm of the night goes to the second biggest cell, which traveled ENE from the OH/IN state line and up along the Maumee River. Skirting the Defiance and Napoleon areas, this storm became warned for ping-pong ball sized hail just after 11pm. The intense updraft of this storm was evident well to the south from my home in Columbus Grove, as the tower was so frequently lit up with lightning flashes and anvil crawlers that you could make out all the features: from the base, inflow bands, little striations, and more. Despite having an AP Calculus exam in the morning, this was too good to pass up, so I ventured north and got these shots from a distance as the cell continued ENE toward Toledo. (2-5) 

So, all in all, not a bad evening. This guy gets structure of the year for me so far. Now, if we can just keep this up...

 

 

[snowlover2]

SPC mentioning possible severe weather on Saturday and Sunday for southern GL/OV areas.

Quote

  Day 4-8 Convective Outlook 
   NWS Storm Prediction Center Norman OK
   0355 AM CDT Wed May 16 2018

   Valid 191200Z - 241200Z

   ...DISCUSSION...
   Models indicate that there may be some adjustments to the mid/upper
   flow during this period.  While it appears that large-scale blocking
   may persist within the mid-latitude westerlies, guidance suggests
   that it will shift inland of the Pacific coast, into areas near/east
   of the Canadian/U.S. Rockies by the middle of next week, as the
   leading edge of a strong zonal Pacific jet approaches the Pacific
   Northwest coast.  As ridging becomes more prominent over interior
   North America, western Atlantic subtropical ridging into the
   Northeast is forecast to become suppressed by broad large-scale
   troughing within the mid-latitude westerlies.  Upstream, another
   southern branch closed low may develop and migrate inland of the
   California coast early next week, before turning northeastward
   toward the northern Rockies.  It appears that this will also
   maintain the suppression of subtropical ridging centered near/south
   of Baja into the Mexican Plateau.

   It might not be out of the question that the remnants of the
   preceding closed low advancing into the central Plains by this
   coming Saturday, and upper portions of the middle Mississippi Valley
   into the vicinity of the southern Great Lakes/Ohio Valley region
   Sunday, could be accompanied by some continuing risk for organized
   severe storm development.  This potential could be a little higher
   Sunday than Saturday, when some possible phasing of the wave with a
   northern branch impulse could result in strengthening wind fields,
   in the presence of better low-level moisture near/east of the
   Mississippi Valley.  At the present time, due to substantial
   lingering uncertainties, severe probabilities are being maintained
   at less than 15 percent, and severe weather potential through the
   remainder of the period still appears relatively low.

   ..Kerr.. 05/16/

 

[hlcater]

NAM/GFS 12z runs look nice along the warm front on Saturday, but the position and to a degree, the orientation of this boundary is still up in the air.