9-22-06 Mid Mississippi Valley Tornado Outbreak

[TexasStooge]

Not again butler county...

any live streamTV available?

If there is any, take a look at the list of stations in Oklahoma, Kansas, and Texas on the Media Coverage thread that's put together:

http://www.storm2k.org/phpbb2/viewtopic ... 34#1467734

[CrazyC83]

Not again butler county...

any live streamTV available?

I don't think so.

Indeed - nothing. i just tried

Being a mostly rural area, that makes sense.

9 tornadoes now reported.

[CrazyC83]

MESOSCALE DISCUSSION 1995
NWS STORM PREDICTION CENTER NORMAN OK
0500 PM CDT THU SEP 21 2006

AREAS AFFECTED...CENTRAL/EASTERN KS AND CENTRAL/EASTERN OK

CONCERNING...TORNADO WATCH 782...

VALID 212200Z - 212330Z

VALID PORTION OF TORNADO WATCH 782 CONTINUES UNTIL 03Z ACROSS
CENTRAL/EASTERN KS AND CENTRAL/EASTERN OK...WITH CONTINUED POTENTIAL
FOR ISOLATED TORNADOES AND HAIL.

NEARLY STACKED COLD CORE LOW CONTINUES TO PIVOT SLOWLY EASTWARD
ACROSS CENTRAL KS...WITH ATTENDANT OCCLUDED FRONT ARCING ROUGHLY
PARALLEL TO THE I-35/135 CORRIDOR FROM NORTH CENTRAL KS INTO CENTRAL
OK. SCATTERED MINI-SUPERCELLS WITH SUSTAINED LOW LEVEL ROTATION HAVE
BEEN COMMON ALONG THE OCCLUDED BOUNDARY...WITH A NUMBER OF TORNADO
REPORTS ACROSS NORTH CENTRAL KS IN MITCHELL/RUSSELL/LINCOLN
COUNTIES.

WHILE THE ENVIRONMENT IS CHARACTERIZED BY RATHER MODEST TOTAL CAPE
-- GENERALLY 500 J/KG MLCAPE OR LESS -- A RELATIVELY HIGH
CONCENTRATION OF 0-3 KM CAPE OF AROUND 100 J/KG AND ENLARGED LOW
LEVEL HODOGRAPHS WITH 0-1 KM SRH IN EXCESS OF 300 M2/S2 WILL REMAIN
FAVORABLE FOR LOW LEVEL ROTATION/ISOLATED TORNADOES.

ONGOING STORMS ACROSS NORTH CENTRAL KS SHOULD TEND TO WEAKEN OVER
THE NEXT FEW HOURS AS RAIN COOLED/MORE STABLE AIR BECOMES MORE
PREVALENT ALONG THE OCCLUSION. MEANWHILE...IT APPEARS LIKELY THAT AT
LEAST ISOLATED DEVELOPMENT WILL OCCUR ACROSS FAR SOUTH CENTRAL KS
INTO NORTHEAST/EAST CENTRAL OK THROUGH EARLY EVENING...WITH
CONDITIONAL POTENTIAL FOR ISOLATED TORNADOES/HAIL AND ENHANCED WIND
GUSTS INCREASING.

..GUYER.. 09/21/2006


ATTN...WFO...SGF...TSA...TOP...ICT...OUN...GID...

39119838 39299775 38239621 37429516 36579491 35579498
35139621 35239710 36919728 37729767

[TexasStooge]

Just got a Short Term Forecast from the NWS in Ft. Worth:

Code: Select all

SHORT TERM FORECAST
NATIONAL WEATHER SERVICE FORT WORTH TX
448 PM CDT THU SEP 21 2006

TXZ091>095-100>107-115>123-133-134-212341-
COLLIN-COOKE-DALLAS-DELTA-DENTON-ELLIS-FANNIN-GRAYSON-HOPKINS-HUNT-
JACK-JOHNSON-KAUFMAN-LAMAR-MONTAGUE-PALO PINTO-PARKER-RAINS-ROCKWALL-
STEPHENS-TARRANT-VAN ZANDT-WISE-YOUNG-
448 PM CDT THU SEP 21 2006

.NOW...
A TORNADO WATCH IS IN EFFECT THROUGH MIDNIGHT...ALONG AND TO THE
NORTH OF INTERSTATE 20.

A POWERFUL UPPER LEVEL STORM SYSTEM IN KANSAS IS CAUSING A DRY LINE
TO MOVE INTO THE EXTREME NORTHWESTERN PARTS OF NORTH TEXAS.  AT 5
PM THE DRY LINE WAS LOCATED ALONG A LINE FROM BRECKENRIDGE...TO
GRAHAM...TO DUNCAN OKLAHOMA.  ISOLATED SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF THIS DRY LINE BETWEEN 5
AND 7 PM.

BECAUSE THE ATMOSPHERE IS UNSTABLE AND DUE TO STRONG TURNING OF WINDS
WITH HEIGHT...THERE IS THE POTENTIAL FOR SEVERE WEATHER ACROSS THE
TORNADO WATCH AREA THIS EVENING.  SHOWERS AND THUNDERSTORMS WILL MOVE
TO THE NORTHEAST AT 40 MPH...AND PERSONS ENGAGED IN OUTDOOR
ACTIVITIES SHOULD KEEP AN EYE TO THE WESTERN SKY AND MOVE INDOOR
SHOULD THREATENING WEATHER APPROACH.

[wxmann_91]

While I dont expect a tornado outbreak at any time today through saturday..a significant episode appears likely at least saturday. I think SPC is too agressive on the tornado threat today...nocturnal tornadoes are hard to get and...the destabilization zone with all that rain looks very narrow. Id say more like a 5% area...and in central KS ahead of the low.

friday is a little more potent but still not major IMO. low will close off in iowa with another emerging out of Colorado. Looks like there will be significant rain and cloud cover over the warm sector friday morning... and Im not sure if the low level moisture will be good enough. Id say Arkansas is the best bet for severe friday.

saturday the low emerging on Friday should really move northeastward and deepen a bit. I expect a low near 1000 mb in IL by saturday afternoon. Positive tilt of trough nature with a sagging front makes me believe the tornado threat wont be too high, but more of a line segment affair. Will opt to go with a broad 5% tornado threat on saturday, with a localization to 10...perhaps 15% on the day 1. If the cyclone is more intense than i am thinking, or an area of significant low level moisture/destabilization cooincide and develop together, a narrow moderate risk might become necessary. Will monitor this event..especially saturday.

I agree, and I too think Friday is the big day. Tonight, the stronger low level shear will be unjuxtaposed with the best low level moisture. Screaming LLJ of 60 kt (!) will be over western MO but the dewpoints are not even 50 there. It turns out that SPC was also forecasting a nocturnal outbreak on March 8 earlier this year in the exact same area they are forecasting a nocturnal outbreak today. It busted. Likewise, unless I see 60's dewpoints reach MO where the 60 kt LLJ yes, or the LLJ in the MDT risk area can strengthen to >50 kt, I'm not going to count on the boundary layer remaining coupled enough to support a nocturnal outbreak.

Saturday the best dynamics outrun the best instability, quite common actually for this to happen, I'm not even looking at it.

Still some details need to be sorted out but actually I believe Goss is a little too bullish. I do not expect a high risk tomorrow unless the 0Z models can somehow drastically change.

[wxmann_91]

Wow, this really appeared unexpected, isn´t it ?

Well, there were vague signs of it, but to explode this fast was unexpected.

Now 7 tornadoes today.

This was a classic cold core setup. When temperatures aren't that high and we've got a strong vertically stacked low barreling toward the area, it doesn't take much instability for a serious outbreak. (11/27/05 would be a good example.) It's too bad that the SPC will many times miss cold core setups. (although I'm not bashing them by any means)

[CrazyC83]

MESOSCALE DISCUSSION 1996
NWS STORM PREDICTION CENTER NORMAN OK
0551 PM CDT THU SEP 21 2006

AREAS AFFECTED...NCNTRL/NERN TX...SERN OK AND WRN AR

CONCERNING...TORNADO WATCH 783...

VALID 212251Z - 220045Z

22Z MESOANALYSIS PLACES A 985 MB LOW OVER NCNTRL KS WITH A DRYLINE
EXTENDING SWD THROUGH CNTRL OK AND INTO NCNTRL TX JUST WEST OF KABI.
A DOUBLE STRUCTURE WARM FRONT EXISTED ACROSS THE ARKLATEX. THE
NRN-MOST FEATURE EXTENDING FROM THE LOW SEWD ACROSS NERN OK INTO
SWRN AR. A MARINE WARM FRONT...A DEMARCATION OF MORE QUALITY
TROPICAL MSTR...WAS LIFTING NWD THROUGH NERN TX AND SWRN LA.

WATER VAPOR IMAGERY SUGGESTS THAT A WEAK MID-LEVEL JETLET MAY BE
MIGRATING INTO THE RED RVR REGION ALONG THE BASE OF THE UPPER LOW.
MESOANALYSIS TIME SERIES SHOWS THAT A REGION OF MODEST PRESSURE
FALLS HAS PERSISTED ACROSS THE METROPLEX AND MAY BE A REFLECTION OF
THIS MID-LEVEL JETLET. THOUGH THE CUMULUS ALONG THE DRYLINE APPEAR
FLAT...WARM ADVECTION HAS BEEN INCREASING ACROSS SERN OK AND NERN TX
WHERE CONVECTIVE CLOUDS HAVE BEEN GROWING. IN FACT...A FEW TSTMS
WERE BEGINNING TO DEVELOP IN THIS REGION.

LATEST RUC IS SIMILAR TO PREVIOUS MODEL RUNS IN INCREASING TSTMS
FROM EXTREME NERN TX NEWD INTO WRN AR THROUGH LATE EVENING. MORE
QUALITY MSTR WAS LAGGING SOMEWHAT SOUTH OF THE REGION...BUT COULD
BECOME A FACTOR IN FURTHER DESTABILIZATION LATER ON. TSTMS THAT CAN
MANAGE TO BECOME ROOTED INTO THIS ENVIRONMENT COULD BECOME
SUPERCELLULAR GIVEN FAVORABLE VERTICAL SHEAR. RIGHT-MOVING STORMS
WILL HAVE ACCESS TO 250+ M2/S2 0-1KM STORM RELATIVE HELICITY...
INCREASING THE RISK OF TORNADOES. THIS WILL BE ESPECIALLY THE CASE
FOR STORMS THAT CAN DEVELOP VCNTY THE RED RVR IN NERN TX AND SERN OK
EWD INTO SWRN AR...OR ALONG THE NRN EDGE OF THE RETURNING TROPICAL
ENVIRONMENT.

..RACY.. 09/21/2006

[CrazyC83]

One thing to remember:

If the SPC goes High Risk tomorrow, it would be the first time EVER that they would have done so in the month of September. It is the only month with no High Risk issuances so far.

[CrazyC83]

The activity is starting to pick up in the MDT area.

[HurricaneBill]

The activity is starting to pick up in the MDT area.

There was a little activity in Louisiana too.

[WindRunner]

Watch this Atoka County OK cell . . . 73dBz just showed up on the lowest tilt, and SRV is showing a decent couplet. Also, it appears an odd-angled hook is trying to form with this cell. They already issued the TOR for the county ahead of it, which it shouldn't be near for another 20mins or so.

[simplykristi]

Is that the couty near Muskogee? Or in NE OK?

Kristi

[CrazyC83]

The Muskogee cell has no warning, but a TVS (23kt) indicated. Should be a tornado warning on that cell.

[JonathanBelles]

The Muskogee cell has no warning, but a TVS (23kt) indicated. Should be a tornado warning on that cell.

just like the supercell the other day that killed a 10 year old girl

[simplykristi]

Looks like that cell in NE OK is weakening.

That stom to the east of Muskogee looks wicked.

Kristi

[CrazyC83]

Forecast Discussion
SPC AC 220048

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0748 PM CDT THU SEP 21 2006

VALID 220100Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF SERN OK...NERN TX
AND SWRN AR...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL/SRN
PLAINS INTO MO AND AR...

...ERN PORTION OF CENTRAL/SRN PLAINS...
WATER VAPOR IMAGERY SHOWS A VIGOROUS UPPER LOW OVER NRN KS LIFTING
NNEWD INTO NEB IN RESPONSE TO UPSTREAM VORTICITY MAX DIGGING SEWD
ACROSS THE NRN INTERMOUNTAIN REGION. OCCLUDED SURFACE LOW NORTH OF
CNK IS EXPECTED TO CONTINUE MOVING NEWD INTO ERN NEB TONIGHT. NRN
PART OF SURFACE DRY LINE ARCING SWD FROM THE LOW ACROSS KS WILL MOVE
INTO ERN KS...WHILE SRN PART OF DRYLINE ACROSS CENTRAL OK AND NORTH
CENTRAL TX IS EXPECTED TO BECOME QUASI-STATIONARY AS STRONGEST
DYNAMIC FORCING LIFTS NWD WITH TIME.

A RELATIVELY NARROW WARM SECTOR HAS BECOME ESTABLISHED FROM
CENTRAL/ERN TX NWD INTO ERN PARTS OF OK AND KS WITH SURFACE DEW
POINTS IN THE LOW/MID 60S EXTENDING AS FAR NORTH AS NERN
OK...DROPPING INTO THE 50S IN ERN KS. COLD AIR ALOFT AND STEEPER
LAPSE RATES ARE LOCATED IN THE IMMEDIATE PROXIMITY OF THE NRN KS
UPPER LOW...WITH PROGRESSIVELY WARMER MID LEVEL TEMPERATURES/WEAKER
LAPSE RATES SWD INTO THE LOW LEVEL MOIST AXIS ACROSS ERN OK AND
CENTRAL/ERN TX. THIS IS RESULTING IN MLCAPE OF AROUND 1000 J/KG
OVER ERN PARTS OF OK AND TX.

EARLIER TORNADIC THUNDERSTORMS OVER CENTRAL KS HAVE MOVED NWD AND
WEAKENED...WHILE NEW STORMS ARE DEVELOPING FROM SERN KS ACROSS ERN
OK. VAD AND PROFILERS EXHIBIT WINDS THAT VEER AND INCREASE IN SPEED
WITH HEIGHT...RESULTING IN STRONG DEEP LAYER VERTICAL SHEAR OF 50-60
KT...AND SRH OF 200-400 MS/S2 IN THE LOWEST 1-3 KM AGL. THE WIND
PROFILES ARE STRONGLY SUPPORTIVE OF SUPERCELL DEVELOPMENT FOR STORMS
THAT CAN REMAIN DISCRETE...AND THE THREAT FOR TORNADOES WILL BE
ENHANCED BY RELATIVELY LOW LCL HEIGHTS AND FAVORABLE SHEAR/SRH IN
THE LOWEST 1 KM. MODEL GUIDANCE FROM RUC...NAM AND SREF AGREE WITH
OBSERVATIONAL DATA SHOWING FOCUS ON THE SERN OK/NERN TX/SWRN AR
REGION FOR AN INCREASED SEVERE POTENTIAL THROUGH THE EVENING HOURS
AND THE HIGHEST SEVERE PROBABILITIES/MODERATE RISK REGION WILL BE
MAINTAINED OVER THIS AREA.

STORMS ARE LIKELY TO SPREAD NEWD INTO MO AND AR DURING THE OVERNIGHT
HOURS...CONSOLIDATING INTO ONE OF MORE MCS/S ARE THEY MOVE INTO A
REGION OF INCREASINGLY ELEVATED INSTABILITY. ALTHOUGH THREAT FOR
TORNADOES AND DAMAGING WIND GUSTS IS EXPECTED TO DIMINISH LATER
TONIGHT...POTENTIAL FOR ISOLATED LARGE HAIL WILL LIKELY CONTINUE
THROUGH THE NIGHT ACROSS MO AND PARTS OF CENTRAL/ERN AR.

..WEISS.. 09/22/2006

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
CURRENT UTC TIME: 0111Z (9:11PM), RELOAD THIS PAGE TO UPDATE THE TIME

[simplykristi]

Line of heavy storms off to my south and west in eastern KS.

Kristi

[CrazyC83]

I agree, that cell is quite intense. Surprised there are no warnings on it. Mind you, there isn't a well-defined hook, but at least a Severe Thunderstorm Warning should be on that cell...

[CrazyC83]

Line of heavy storms off to my south and west in eastern KS.

Kristi

Yep, one of them now has a Tornado Warning on it.

[simplykristi]

That is Miami County KS. OOPS That should be Linn County KS not Miami County KS that has the Tornado Warning.


Kristi