Apr. 2-4 Severe Threat

[Hoosier]

49 minutes ago, andyhb said:

Care to offer a reason why? Broyles was not the only one on that forecast.

Usually when you see the SREF tornado ingredients popping a 90...there's some credence to a significant tornado threat.

Yeah, 90 is usually a pretty good signal for something, whether we are talking about 1, 5, or 10 sig tors.  I guess this comes down to how many of them are expected in a 10% hatched area of this size.

[IWXwx]

It looks like Indystorm had some peas in Fortville. Meanwhile, two more cells are training through Indy metro that are gully washers and dropping nickles. Next stop, Fortville once again.

[Stebo]

2 hours ago, Chicago Storm said:

This is not a 10% hatched kind of day.

Broyles’d again.


.

I would disagree, the parameter space is such that if any prefrontal convection does occur, the potential is there for a couple of significant tornadoes. You have to remember 10% hatched means 90% nothing. I wouldn't be shocked if we get a couple of significant tors today especially across Western KY S IL/IN. Further north it is a bit more conditional but if the conditions do end up in place then yes I could see a couple in the Cinci area after dark this evening.

[tornadohunter]

10 minutes ago, Stebo said:

I would disagree, the parameter space is such that if any prefrontal convection does occur, the potential is there for a couple of significant tornadoes. You have to remember 10% hatched means 90% nothing. I wouldn't be shocked if we get a couple of significant tors today especially across Western KY S IL/IN. Further north it is a bit more conditional but if the conditions do end up in place then yes I could see a couple in the Cinci area after dark this evening.

HRRR has a discrete cell tracking through the 275 loop. Close to cincinnati...

[Jackstraw]

I'm going to guess its due to the cool dense 100% saturated air but every lightning strike in this area all morning sounds like bombs going off.  Maybe its just been awhile 

[Stebo]

1 minute ago, tornadohunter said:

HRRR has a discrete cell tracking through the 275 loop. Close to cincinnati...

Yeah it is those cells just ahead of the lines that will be the ones to watch. Though the front itself back to the west has potential as well too.

[JasonOH]

HRRR initialization hasn't been too great so far with respect to dew points.  If you compare for the 15z HRRR at hour 1 (16z) to the surface map, the dew points are way behind in S IN/IL and W KY.  I'm not thinking the warm front will move as far north as modeled.  I think it will be much further south especially in Ohio with the marginal moisture return so far.  I'm thinking the 60 degree dews make it to somewhere between I70 and US36 in Ohio.  In IN I think the 60 degree dews make it up to a line from Piqua, OH to roughly Lafayette, IN.  Ongoing convection will reinforce the warm front which is why I think higher dew points wont make it as far north in OH.  In C IN, convection is a bit further north, so the warm front should be able to push further north.  I will say, reflectivity initialization wasn't bad on the latest run, so the warming it predicts should be pretty good for the warm sector.  

 

With all of this added together, I think there will be a solid tornado threat from SW KY up through S IL and into S IN.  W OH is much more conditional based on the moisture return being slow.  Observations are key on days like this.

[CheeselandSkies]

MDT risk incoming.

[geddyweather]

SPC looking to go Moderate this update stretching from ~ I-70 to Cincy and then down the OH River toward Paducah and beyond.

[geddyweather]

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1122 AM CDT Tue Apr 03 2018

   Valid 031630Z - 041200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   EASTERN ARKANSAS...NORTHERN MISSISSIPPI...WESTERN AND MIDDLE
   TENNESSEE...SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...WESTERN AND
   CENTRAL KENTUCKY...SOUTHERN AND CENTRAL INDIANA...AND SOUTHWEST
   OHIO...

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   MODERATE RISK AREA OVER PARTS OF THE LOWER AND MID
   MISSISSIPPI...OHIO...AND TENNESSEE VALLEYS...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL TEXAS
   INTO OHIO...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
   TEXAS INTO WESTERN PENNSYLVANIA...

   ...SUMMARY...
   A Moderate Risk for thunderstorms producing widespread damaging
   winds, large hail, and a few tornadoes exists over parts of the Ohio
   Valley and Mid-South regions.

   ...AR/MS northeastward through much of the OH/TN Valleys...
   An active severe weather day is expected across the MS/OH/TN Valleys
   today with numerous strong/severe thunderstorms affecting a large
   area.  The primary focus for severe storms will be a progressive and
   deepening shortwave trough moving across the central Plains.  A
   deepening surface low and cold front in advance of this system will
   sweep across the risk area this afternoon through tonight, resulting
   in a fast-moving squall line extending from IL/IN/OH southward into
   the Mid South.  Visible satellite imagery shows broken cloud cover
   across most of the warm sector, promoting heating and
   destabilization.  Forecast soundings suggest a corridor of moderate
   CAPE values ahead of the front by mid-afternoon as thunderstorms
   begin to form.  Initial activity may be supercellular in nature,
   with a risk of tornadoes (some strong) and large hail from northwest
   AR/western MS into parts of southern IL/IN and western KY. 
   Eventually, the storms should congeal into a line with multiple
   bowing segments as it progresses across the MDT and ENH risk areas
   with the potential for widespread damaging winds and a few QLCS
   tornadoes.

   ...TX/LA...
   Scattered strong to severe thunderstorms have developed this morning
   over central TX, ahead of a southern stream shortwave trough.  This
   activity will persist through the day and spread into LA, with a
   risk of large hail and damaging wind gusts.  By mid-afternoon,
   thunderstorms are expected to form along the advancing cold front
   and affect these same areas.

   ...IN/OH...
   A persistent cluster of thunderstorms is affecting much of
   central/northern IN and OH.  The air mass south of the activity
   continues to warm, leading to a favorable environment for
   severe/supercell thunderstorms.  This corridor remains in the higher
   tornado/damaging wind probability area for both warm frontal
   activity this afternoon, and the squall line activity later today.

   ..Hart/Jewell.. 04/03/2018

 

[CoachLB]

[Jackstraw]

Tor watch coming.  I'm liking the the southern flank of the line moving into Central and southern IN atm.

[tornadohunter]

47 minutes ago, Stebo said:

1 minute ago, Jackstraw said:

Tor watch coming.  I'm liking the the southern flank of the line moving into Central and southern IN atm.

  Mesoscale Discussion 0205
   NWS Storm Prediction Center Norman OK
   1141 AM CDT Tue Apr 03 2018

   Areas affected...Central and southern Indiana...far northern
   Kentucky...western Ohio

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

   Valid 031641Z - 031915Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Storms are expected to increase in intensity this
   afternoon with a few tornadoes possible along with large hail.
   Additional severe storms are likely later this evening.

   DISCUSSION...Scattered storms persist from southern IL across
   central IN and into OH along and north of a warm front. This
   boundary will gradually shift northward due to boundary layer
   heating/mixing to the south and strengthening warm air advection via
   a backing 50-60 kt low-level jet. While some of the activity is
   currently elevated, a transition may occur in a few hours allowing
   storms along the warm front to become supercells and/or bows.
   Additional storms may also form south of the warm front as the air
   mass continues to destabilize, most likely across southern IN, far
   northern KY, and southwest OH. Wind profiles will become
   increasingly favorable for supercells and tornadoes throughout the
   day as the low deepens.

[Jackstraw]

^ It was just a reminder lol

[geddyweather]

Shear is really jacked across south central IN/OH currently. 50-60kts 0-6km, 35-40kts at the lowest levels (0-1km). CAPE starting to surge into that area as well. Hedge a bet that we see at least a couple TORs in that region. Damaging wind threat is also amplified with those tall numbers.

[Sydney Claridge]

32 minutes ago, JasonOH said:

HRRR initialization hasn't been too great so far with respect to dew points.  If you compare for the 15z HRRR at hour 1 (16z) to the surface map, the dew points are way behind in S IN/IL and W KY.  I'm not thinking the warm front will move as far north as modeled.  I think it will be much further south especially in Ohio with the marginal moisture return so far.  I'm thinking the 60 degree dews make it to somewhere between I70 and US36 in Ohio.  In IN I think the 60 degree dews make it up to a line from Piqua, OH to roughly Lafayette, IN.  Ongoing convection will reinforce the warm front which is why I think higher dew points wont make it as far north in OH.  In C IN, convection is a bit further north, so the warm front should be able to push further north.  I will say, reflectivity initialization wasn't bad on the latest run, so the warming it predicts should be pretty good for the warm sector.  

 

With all of this added together, I think there will be a solid tornado threat from SW KY up through S IL and into S IN.  W OH is much more conditional based on the moisture return being slow.  Observations are key on days like this.

Upper 60s to lower 70s air temperatures have made it into SW Ohio around Cincinnati, where clearing has occurred.  Columbus and Dayton are still in the lower-to-mid 50s.

For what its worth, the 15z HRRR is depicting at least two stronger cells forming along the I-70 corridor in central Ohio, including moving one over the Columbus metro area.  If the warmer air can make it that far north, perhaps some tornadoes could occur in the vicinity of the warm front, although the model run depicts the warm front just south of Columbus.  The 16z HRRR is moving the 60s dewpoints across the Columbus metro, though the storms depicted don't seem as strong.

[Snowless in Carrollton]

Its a little eerie that this is happening on the anniversary of the 1974 outbreak. Hopefully this will be nothing like that one.

[Indystorm]

Just drove back to Fortville from nw IN Calumet region this morning. Fog and light rain down 65 to LAF then heavy t storms se of there to just north of Noblesville with the WF.  55 and cloudy here now with lighter skies to my south.  As indicated above tor watch coming soon.   Flooding was extensive.  IN 47 west of Sheridan and east of I-65 was flooded in two places over the highway from farm fields overflowing.

[geddyweather]

3 minutes ago, BrandonC_TX said:

Upper 60s to lower 70s air temperatures have made it into SW Ohio around Cincinnati, where clearing has occurred.  Columbus and Dayton are still in the lower-to-mid 50s.

For what its worth, the 15z HRRR is depicting at least two stronger cells forming along the I-70 corridor in central Ohio, including moving one over the Columbus metro area.  If the warmer air can make it that far north, perhaps some tornadoes could occur in the vicinity of the warm front, although the model run depicts the warm front just south of Columbus.  The 16z HRRR is moving the 60s dewpoints across the Columbus metro, though the storms depicted don't seem as strong.

Can confirm the sun is out in and around the Cincy area. Friend in Glendale just sent a photo. That will really amp things up there.

[andyhb]

2 minutes ago, Snowless in Carrollton said:

Its a little eerie that this is happening on the anniversary of the 1974 outbreak. Hopefully this will be nothing like that one.

Yeah, I think you can count on that.

[sjm_888]

2 minutes ago, geddyweather said:

Can confirm the sun is out in and around the Cincy area. Friend in Glendale just sent a photo. That will really amp things up there.

South of Dayton here, sun is out and temp has risen 3 degrees to 58 in a matter of minutes. Should be in mid 60's in an hour of two.

TOR watch just issued.

[CoachLB]

[Indystorm]

60/40 probs on tors in watch area.  Gonna be an active day.

[Jackstraw]

Yards a lake, little over 2in in the last 12 hours on top of snow melt.

[NoDoppler4TnySandz]

Cincy heating up indeed -- pushing mid 70s (car thermometer) but the clouds are starting to fill in over the sun shine.....

[rolltide_130]

44 minutes ago, Snowless in Carrollton said:

Its a little eerie that this is happening on the anniversary of the 1974 outbreak. Hopefully this will be nothing like that one.

The odds of that happening are non-existent. This is a sig threat but not a massive outbreak.

[JPOracle]

Today looking like an active day, Indiana into Ohio looks to like going to light up like a Christmas tree

[Indystorm]

New tor watch coming for southern IL,, se MO bootheel on down to Arkansas and Memphis.  Partial clearing west of the Wabash over to St.Louis on southward will increase insolation and instability.

[Indystorm]

70/50 probs for tors in new watch issuance and HIGH risk almost all across the board!

[Chinook]

1 minute ago, Indystorm said:

70/50 probs for tors in new watch issuance and HIGH risk almost all across the board!

There is not a high risk posted right now.