Plains Tornado Outbreak 4/14-15

[CrazyC83]

MESOSCALE DISCUSSION 0509
NWS STORM PREDICTION CENTER NORMAN OK
0237 PM CDT FRI APR 13 2012

AREAS AFFECTED...SERN KS THROUGH A PORTION OF EXTREME SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 131937Z - 132130Z

A FEW STORMS MAY DEVELOP OVER SERN KS BY 21Z. SUPERCELLS WITH
ISOLATED LARGE HAIL WILL BE THE PRIMARY THREAT...BUT AN ISOLATED
TORNADO OR TWO CANNOT BE RULED OUT...MAINLY DURING THE EARLY
EVENING.

EARLY THIS AFTERNOON A WEAK FRONTAL BOUNDARY EXTENDS FROM NERN KS
SWWD THROUGH S-CNTRL KS AND WRN OK. THE ATMOSPHERE HAS DESTABILIZED
IN MOIST WARM SECTOR WHERE DIABATIC WARMING AND LOW 60S DEWPOINTS
BENEATH STEEP LAPSE RATES HAVE CONTRIBUTED TO 1500-2000 J/KG MLCAPE.
CUMULUS IS INCREASING ALONG THE BOUNDARY AS WELL AS IN WARM SECTOR
AND LATEST OBJECTIVE ANALYSIS SHOWS ONLY A WEAK CAP REMAINING.
THEREFORE A FEW STORMS WILL LIKELY DEVELOP WITHIN THE NEXT HOUR OR
SO. LOW LEVEL SHEAR HAS DECREASED IN WAKE OF PRIMARY LLJ THAT HAS
SHIFTED NEWD INTO THE MID MS VALLEY AREA. HOWEVER...DEEP SHEAR OF
35-40 KT WILL SUPPORT SUPERCELLS CAPABLE OF MAINLY ISOLATED LARGE
HAIL. SOME THREAT FOR AN ISOLATED TORNADO OR TWO MAY INCREASE TOWARD
EVENING AS THE LLJ STRENGTHENS.

..DIAL.. 04/13/2012


ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON 37059501 37059604 37049694 37499635 38339583 38829520
38059466 37509430 37059501

[CrazyC83]

I have a REALLY, REALLY bad feeling about this. This setup is like something I have never seen before in the Plains and Midwest...from Minnesota to Texas.

[Ntxw]

I have a REALLY, REALLY bad feeling about this. This setup is like something I have never seen before in the Plains and Midwest...from Minnesota to Texas.

This is actually a very typical significant multi-day outbreak for the plains. If anywhere in the country this most likely place to happen, also the most prepared, not to say it isn't dangerous...

Mid morning tomorrow for the central plains looks bad, then later in the evening along I-35.

SW-Central-NE Ok and SE Kansas this evening.

[CrazyC83]

20Z: virtually unchanged it appears

[TwisterFanatic]

I have a REALLY, REALLY bad feeling about this. This setup is like something I have never seen before in the Plains and Midwest...from Minnesota to Texas.

This is actually a very typical significant multi-day outbreak for the plains. If anywhere in the country this most likely place to happen, also the most prepared, not to say it isn't dangerous...

It might be a 'typical' April set-up, but the parameters a off the charts.

[apocalypt-flyer]

News media is already picking it up, using terms like 'life threatening'.

Considering the variables in the equation for tomorrow's setup there's nothing wrong with that given that quite a number of official watches and warnings will include that term. Though I do know what you mean but I reckon tomorrow's scenario will justify it. Unfortunately.

[CrazyC83]

No change.

SPC AC 131951

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0251 PM CDT FRI APR 13 2012

VALID 132000Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR NWRN TX...OK...SERN
KS...SWRN MO AND NWRN AR...

NO CHANGES WERE REQUIRED TO THE SLIGHT RISK AREA. PREVIOUS
DISCUSSION REMAINS VALID.

...SRN CA...
HAVE REMOVED THE SEVERE HAIL PROBABILITIES OVER SRN CA. IT APPEARS
THAT INSTABILITY WILL REMAIN WEAK ENOUGH SUCH THAT ANY HAIL SHOULD
REMAIN SUB-SEVERE. SOME OF THE STRONGER CELLS MAY CONTAIN PEA TO
MARBLE SIZE HAIL.

..JEWELL.. 04/13/2012

.PREV DISCUSSION... /ISSUED 1225 PM CDT FRI APR 13 2012/

[EF-5bigj]

Well im glad its getting coverage that it is I hope the violent one's don't move through cities but it may happen. Give KS and Ok records of violent tornadoes hitting populated area's

[CrazyC83]

I have a REALLY, REALLY bad feeling about this. This setup is like something I have never seen before in the Plains and Midwest...from Minnesota to Texas.

This is actually a very typical significant multi-day outbreak for the plains. If anywhere in the country this most likely place to happen, also the most prepared, not to say it isn't dangerous...

It might be a 'typical' April set-up, but the parameters a off the charts.

The parameters look most similar to April 27, 2011 except in the Plains where such an extreme outbreak (Super Outbreak-like) has never happened that we know of.

[Ntxw]

It might be a 'typical' April set-up, but the parameters a off the charts.

The off the charts parameters are located near I-70 corridor and just north with the warm front. Juicy down south but capping might be an issue/savior down south.

[CrazyC83]

Tweet from Jon Haverfield:

Reports saying SPC is considering an upgrade past high risk for tomorrow... Could be first time that it has happened.. #okwx #kswx

Extreme Risk anyone? How high will the tornado probs be on the Day 1 outlook, could a 60% tornado threat exist?

[TwisterFanatic]

Looks as if the storm just north of Mountain Park, OK is starting to develop a hook echo. Broad rotation on velocity.

[TwisterFanatic]

It might be a 'typical' April set-up, but the parameters a off the charts.

The off the charts parameters are located near I-70 corridor and just north with the warm front. Juicy down south but capping might be an issue/savior down south.

Capping should not be a problem, some question of the amount of convergence though. Storm coverage looked to be an issue today, but radar is lighting up.

[TwisterFanatic]

Wall could be observed on the storm Southwest of Oklahoma City by News9 out of OKC.

[Ntxw]

Capping should not be a problem, some question of the amount of convergence though. Storm coverage looked to be an issue today, but radar is lighting up.

Comment was regarding tomorrow's significant outbreak. Storms have already broken the cap today, though later in NE OK, SE KS might get more serious this afternoon as instability and dewpoints there are much higher.

[Extratropical94]

Tweet from Jon Haverfield:

Reports saying SPC is considering an upgrade past high risk for tomorrow... Could be first time that it has happened.. #okwx #kswx

Extreme Risk anyone? How high will the tornado probs be on the Day 1 outlook, could a 60% tornado threat exist?

Wait... what? Seriously?

I don't think tweeting such things is very helpful. It's probably not gonna be worse than April 27, 2011, not saying that it's gonna be a bust.
But seriously, why would they think of inventing new categories? That might kill the intimidating effect of a high risk, just as a category 6 for 'canes would make category 5ers look weaker and more harmless.

[TwisterFanatic]

Capping should not be a problem, some question of the amount of convergence though. Storm coverage looked to be an issue today, but radar is lighting up.

Comment was regarding tomorrow's significant outbreak. Storms have already broken the cap today, though later in NE OK, SE KS might get more serious this afternoon as instability and dewpoints there are much higher.

Oh, I know. I was just making a general statement about today in my last sentence in my post to you.

[Bunkertor]

Tweet from Jon Haverfield:

Reports saying SPC is considering an upgrade past high risk for tomorrow... Could be first time that it has happened.. #okwx #kswx

Extreme Risk anyone? How high will the tornado probs be on the Day 1 outlook, could a 60% tornado threat exist?

The Tusca tor:cons were much higher. How much is the G2G considering the Jet impacts at 100kt.

[TwisterFanatic]

But I agree about this evening, wind fields will also pick up in the next couple hours or so.

[Bunkertor]

Found this surfing Crazys tweet posts.

NWS Norman ‏ @NWSNorman
From @NWSNorman: WINDOW OF OPPORTUNITY FOR A STRONG TORNADO THIS EVENING WITH LOW LEVEL JET...ENHANCING INFLOW AND LOW LEVEL ROTATION. #okwx