Severe Weather - April 26th - Potential Tornado Outbreak

[Thunder]

Other storms in NW OK.

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
456 PM CDT SUN APR 26 2009

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
NORTHWESTERN DEWEY COUNTY IN NORTHWEST OKLAHOMA...
SOUTHEASTERN ELLIS COUNTY IN NORTHWEST OKLAHOMA...
SOUTHERN WOODWARD COUNTY IN NORTHWEST OKLAHOMA...

* UNTIL 600 PM CDT

* AT 456 PM CDT...A THUNDERSTORM WITH A HISTORY OF PRODUCING
TORNADOES WAS LOCATED 12 MILES SOUTH OF HARMON...MOVING NORTHEAST
AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE HARMON...MUTUAL...SHARON AND VICI.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. LEAVE MOBILE HOMES AND VEHICLES. IF POSSIBLE...MOVE
TO A BASEMENT OR STORM SHELTER. OTHERWISE MOVE TO AN INTERIOR ROOM OR
HALLWAY ON THE LOWEST FLOOR. STAY AWAY FROM WINDOWS AND OUTSIDE
WALLS.

[venture]

Bulletin - eas activation requested
tornado warning
national weather service norman ok
542 pm cdt sun apr 26 2009

the national weather service in norman has issued a

* tornado warning for...
Northwestern major county in northwest oklahoma...
Southeastern woods county in northwest oklahoma...
Eastern woodward county in northwest oklahoma...

* until 645 pm cdt

* at 542 pm cdt...a thunderstorm with a history of producing
tornadoes was located 15 miles southwest of quinlan...moving
northeast at 40 mph.

* locations in the warning include avard...hopeton...quinlan and
waynoka.

[venture]

Radar run down.

On going tornadic storm in NW Oklahoma. Main area is north of Mutual on US 183 at County Road N2130. This will move into the Quinlan, Waynoka, and Mooreland areas.

Southwest Oklahoma storms, which have potential to impact the Metro in a couple to few hours. Strong is over Snyder right now moving NE. Its structure has been fluctuating quite a bit lately. It will need to be watched as it moves into a better environment for tornadoes.

Another storm is near Mangum down to Gould to Eldorado, then a break and another storm over Quanah, TX. Sporadic rotation is shown on radar with these. These will likely develop further as they move north.

[venture]

Bulletin - eas activation requested
tornado warning
national weather service norman ok
547 pm cdt sun apr 26 2009

the national weather service in norman has issued a

* tornado warning for...
Northwestern dewey county in northwest oklahoma...
Southeastern ellis county in northwest oklahoma...
Southwestern woodward county in northwest oklahoma...
Northwestern roger mills county in western oklahoma...

* until 645 pm cdt

* at 548 pm cdt...national weather service doppler radar indicated a
severe thunderstorm capable of producing a tornado 3 miles west of
crawford...moving northeast at 20 mph.

* locations in the warning include crawford and harmon.

[venture]

Short term forecast
national weather service norman ok
543 pm cdt sun apr 26 2009

.now...
...regional weather discussion...

Early this evening...radar and satellite observations...along with forecast models...indicated that severe storms will occur in two primary clusters. One cluster was in progress over northwest oklahoma from reydon to near woodward and alva. Thunderstorms will develop repeatedly where an outflow boundary intersects a dryline in the eastern texas panhandle...just west of roger mills county oklahoma. A second cluster of storms had formed in western north texas and southwest oklahoma. Supercells were scattered along a line from guthrie to quanah texas...to hollis oklahoma. And a separate isolated supercell was located near frederick oklahoma. These storms will move northeast...and eventually may turn to the east later this evening. All of these storms will produce large hail...and the more isolated storms will produce destructive hail of baseball size or larger.

Although storms were interacting and producing outflow...they were also meeting exceptionally strong inflow. With low pressure intensifying in the texas panhandle...surface winds across north texas and oklahoma had increased from the southeast...at 30 to 40 mph...with some gusts over 50 mph near the inflow to thunderstorms. This will offset the effects of outflow...and maintain a distinct threat of tornadoes into the evening hours.

In addition...flooding is likely to continue with the storm cluster in northwest oklahoma. These storms will move into northern oklahoma
later this evening...and areas that experienced heavy rain on saturday night...will very quickly see runoff and renewed flooding this evening.

[venture]

Mesoscale discussion 0587
nws storm prediction center norman ok
0544 pm cdt sun apr 26 2009

areas affected...portions central/srn ks...central/wrn ok...nw
tx...and ern tx panhandle.

Concerning...tornado watch 190...192...

Valid 262244z - 262345z

the severe weather threat for tornado watch 190...192...continues.

Severe threat -- including potential for significant tornadoes and
damaging hail -- will continue across much of ww areas past
scheduled 00z expiration time for ww 190...and probably well past
03z expiration of ww 192. Therefore...we are planning to replace ww
190 and at least some of 192 with one consolidated/pds tornado watch
that will go past midnight local time. Haskell/throckmorton counties
tx -- in wfo sjt jurisdiction -- are being switched from ww 192 to
ww 193.

Damaging tornado already has been observed by media and chasers with
earlier storm in nw ok now moving into woodward county...and
environment will remain favorable for more of these with any
relatively discrete storms whose inflow is not too disrupted by
other activity. Tornado potential may increase with
pronounced/discrete supercell in sw ok...that should move from fdr
area newd toward caddo county during next couple hours. Additional
activity is expected to develop over ern tx panhandle and nw tx and
move newd as well...with mix of linear...embedded-supercell and bow
modes. Modified raobs...vwp/profiler data and ruc soundings all
indicate boundary layer shear remaining quite favorable and
reactively maximized over wrn ok...extreme s-central ks and portions
nw tx sw of cds -- e.g. 0-1 km srh 300-500 j/kg. Vertical
veer/back/veer profile that has been evident in wind profiles across
this region appears to be contributing to some linear
tendencies...but is progged to become more classically veering with
height through remainder afternoon/evening. Pressure falls analyzed
across nrn tx panhandle...ern ok panhandle and swrn ks indicate sfc
flow will remain favorably backed over this region...keeping
hodographs enlarged. Nearly uncapped air mass with 1500-2000 j/kg
mlcape will be maintained through evening hours as loss of mixing
and moist advection each keep effective inflow parcels nearly
sfc-based.

..edwards.. 04/26/2009

[venture]

Replacement tornado watch...
WWUS30 KWNS 262312
SAW5
SPC AWW 262312
WW 195 TORNADO KS OK TX 262315Z - 270800Z
AXIS..85 STATUTE MILES EAST AND WEST OF LINE..
45WNW EMP/EMPORIA KS/ - 90SW SPS/WICHITA FALLS TX/ ..AVIATION COORDS.. 75NM E/W /38SE SLN - 36NNE ABI/ HAIL SURFACE AND ALOFT..3 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 550. MEAN STORM MOTION VECTOR 23035.

REPLACES WW 190..KS OK TX
REPLACES WW 192..OK TX



URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 195
NWS STORM PREDICTION CENTER NORMAN OK
615 PM CDT SUN APR 26 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTH CENTRAL INTO SOUTHEASTERN KANSAS
WESTERN AND CENTRAL OKLAHOMA
NORTHWEST TEXAS INCLUDING THE EASTERN PANHANDLE

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 615 PM UNTIL
300 AM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 45 MILES WEST NORTHWEST OF
EMPORIA KANSAS TO 90 MILES SOUTHWEST OF WICHITA FALLS TEXAS. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).

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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 190...TORNADO WATCH NUMBER 192. WATCH NUMBER 190 192
WILL NOT BE IN EFFECT AFTER 615 PM CDT. CONTINUE...WW 193...WW
194...

DISCUSSION...COMBINATION OF EXTREME LOW AND DEEP LAYER SHEAR...ALONG
WITH MODERATE INSTABILITY...WILL MAINTAIN ENHANCED RISK OF SEVERE
THUNDERSTORMS THROUGH THE EARLY MORNING HOURS TONIGHT. ACTIVITY
WILL BE SUSTAINED AS STRONG VERTICAL MOTION OVERSPREADS THE REGION
AHEAD OF SHORTWAVE TROUGH MOVING ACROSS THE HIGH PLAINS.
ENVIRONMENT WILL FAVOR LONG-LIVED SUPERCELLS AND BOW ECHO
STRUCTURES. TORNADO THREAT REMAINS HIGH WITH ANY SUSTAINED
SUPERCELLS...ALTHOUGH LOW LEVEL HODOGRAPHS WILL INCREASE AS LLJ
INTENSIFIES THIS EVENING WHICH SHOULD FURTHER INCREASE TORNADO
POTENTIAL. VERY LARGE/DAMAGING HAIL AND DAMAGING WINDS WILL BE
ADDITIONAL HAZARDS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 23035.

TORNADO WATCH PROBABILITIES FOR WT 0195
NWS STORM PREDICTION CENTER NORMAN OK
0618 PM CDT SUN APR 26 2009

WT 0195 PDS
PROBABILITY TABLE:
PROB OF 2 OR MORE TORNADOES : 90%
PROB OF 1 OR MORE STRONG /F2-F5/ TORNADOES : 70%
PROB OF 10 OR MORE SEVERE WIND EVENTS : 50%
PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS : 60%
PROB OF 10 OR MORE SEVERE HAIL EVENTS : 70%
PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES : 80%
PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS : >95%

&&
ATTRIBUTE TABLE:
MAX HAIL /INCHES/ : 3.0
MAX WIND GUSTS SURFACE /KNOTS/ : 60
MAX TOPS /X 100 FEET/ : 550
MEAN STORM MOTION VECTOR /DEGREES AND KNOTS/ : 23035
PARTICULARLY DANGEROUS SITUATION : YES

[Karried]

Now I don't want to go to sleep tonight.. there is probably nothing worse than a night tornado.

[FritterGirl]

Mike Morgan after it again. Three supercells headed toward metro. Peak time between 7:45 and 11 ish. Guess I need to go get the closet prepped. May just sleep there with motorcycle helmet on. Oh boy.

MM said the type of tornado watch is PSA or PDA? (did I hear that correctly weather fans?) - something to the effect that this elevates the severity of the storms (any potential tornados) to a minimum F3.

Yikes!

[venture]

PDS - Particularly Dangerous Situation. If you look at my post a couple back, i have the watch details and probabilities...one is about the tornado intensity.

PROB OF 1 OR MORE STRONG /F2-F5/ TORNADOES : 70%

So that just means than at least 70% chance of at least 1 EF2 or higher.

[FritterGirl]

I think it's time to get the closet put together just in case. So much for watching my PBS show. Looks like I need to keep the weather on.

[venture]

Starting to show some broad rotation on the storm in Kiowa and Caddo Counties. Area of concern would be just south of Mountain View. Storm is moving NNE.

[Karried]

70 % Here ???? omg

[venture]

High Risk has been shifted east to include the entire OKC metro area over night.





DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0759 PM CDT SUN APR 26 2009

VALID 270100Z - 271200Z

...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PART OF SRN KS...MUCH OF
WRN/CENTRAL OK AND WRN PART OF N TX...

...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK AREA
FROM SW TX TO ERN KS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE
UPPER MS VALLEY...

ONGOING SIGNIFICANT SEVERE WEATHER OUTBREAK IS EXPECTED TO PERSIST
WELL AFTER DARK FROM CENTRAL PART OF TX THROUGH MUCH OF OK TO KS.
THREAT FOR LONG-LIVED TORNADIC SUPERCELLS...VERY LARGE/DESTRUCTIVE
HAIL AND DAMAGING WINDS REMAIN POSSIBLE ACROSS THE MODERATE AND HIGH
RISK AREAS INTO THE EARLY MORNING HOURS TONIGHT.

...SRN PLAINS TO CENTRAL/ERN KS AND LOWER MO VALLEY...
HIGH RISK HAS BEEN SHIFTED SLIGHTLY EWD TO HIGHLIGHT THE GREATEST
LIKELIHOOD FOR LONG-LIVED TORNADIC SUPERCELLS THROUGH THIS EVENING
INTO THE EARLY MORNING HOURS TONIGHT...WITH THE ERN EXTENT GENERALLY
RESIDING ALONG THE I-35 CORRIDOR FROM NRN TX TO SRN KS.

EARLY EVENING REGIONAL RADARS INDICATED A QLCS EXTENDING FROM FAR
NWRN MO SWWD THROUGH SRN KS TO NWRN OK...WITH MORE DISCRETE
SUPERCELLS LOCATED FROM SWRN OK TO SW TX. ALTHOUGH 90 KT SWLY MID
LEVEL JET WILL TRANSLATE FROM THE CENTRAL PLAINS TO THE UPPER MS
VALLEY OVERNIGHT...A BAND OF 50-60 KT SWLY MID LEVEL WINDS WILL
ACCOMPANY A SHORT WAVE TROUGH TRACKING EWD ACROSS THE SRN PLAINS.
ASCENT AHEAD OF NM TROUGH WILL MAINTAIN LIKELIHOOD FOR ADDITIONAL
TSTMS DEVELOPING AND SPREADING ENEWD ACROSS THE SRN PLAINS THROUGH
EARLY MONDAY MORNING. THE STRONG MID LEVEL JET COUPLED WITH FURTHER
STRENGTHENING OF A SLY LLJ ACROSS THE SRN PLAINS WILL MAINTAIN
EFFECTIVE BULK SHEAR /35-50 KT/ ACROSS MODERATE/HIGH RISK AREAS.
SLY LLJ WILL SUPPORT RICH MOISTURE INFLOW INTO ONGOING STORMS
RESULTING IN LOW LCLS...WHILE STRONG LLJ INCREASES SIZE OF LOW LEVEL
HODOGRAPH CURVATURE FOR ATTENDANT TORNADO THREAT. IN
ADDITION...STEEP MID LEVEL LAPSE RATES /7-8 C/KM/ SPREADING EWD
ACROSS SRN PLAINS WITH NM TROUGH WILL SUPPORT CONTINUED THREAT FOR
VERY LARGE HAIL FROM KS SWD THROUGH OK TO SW TX.

FARTHER W INTO OK/TX PANHANDLES...LATE AFTERNOON/EARLY EVENING
SURFACE ANALYSES INDICATED THE DRY LINE RETREATING WWD...ENHANCED BY
CONVECTIVE OUTFLOW...THROUGH WEST CENTRAL/SWRN KS AND ALSO TOWARD
CENTRAL PARTS OF OK/TX PANHANDLES. ALTHOUGH STRONGER/SEVERE
ACTIVITY IS LOCATED WELL E OF THE DRY LINE AT THIS TIME FROM NEAR
CDS TO NWRN OK/CENTRAL KS...THERE REMAINS THE POTENTIAL FOR NEW TSTM
DEVELOPMENT LATER THIS EVENING/TONIGHT AS A MID LEVEL TROUGH MOVES
EWD FROM CENTRAL NM. MODERATE INSTABILITY ALONG AND E OF DRY LINE
COMBINED WITH 30-40 KT OF EFFECTIVE SHEAR SUGGESTS ANY NEW
DEVELOPMENT VICINITY OF DRY LINE WOULD POSE A THREAT FOR SEVERE
STORMS.

[rod4soonrs]

What is "shot size hail"? Morgan is inventing hail sizes now.

[jstanthrnme]

I heard that too.

I was looking at KOCO's interactive radar earlier today, and it said "Hen-egg size hail possible" and "teacup size hail". I'm still scratching my head..

[venture]

NWS Norman's HWO kinda disregards the guidance of the people in the same building. lol

855 PM CDT SUN APR 26 2009

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...THIS EVENING AND TONIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A RISK OF SEVERE THUNDERSTORMS ACROSS MOST OF
WESTERN...CENTRAL...AND NORTHERN OKLAHOMA AND WESTERN NORTH TEXAS.

LOCATION...
ALL OF WESTERN...NORTHERN...CENTRAL AND SOUTHERN OKLAHOMA AND
ADJACENT AREAS OF WESTERN NORTH TEXAS.

TIMING...
WIDELY SCATTERED TO SCATTERED SEVERE WEATHER WILL CONTINUE THROUGH
AT LEAST MIDNIGHT...WITH A SLOW DECREASE IN THE NUMBER OF SEVERE
STORMS AFTER MIDNIGHT.

IMPACTS...
HAIL UP TO THE SIZE OF GOLFBALLS.
WIND GUSTS TO 70 MPH.
FLOODING
MAYBE TORNADOES.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL WILL NEED TO
CONTINUE SEVERE WEATHER OPERATIONS THIS EVENING AND INTO THE NIGHT.

DISCUSSION...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS WEST TEXAS AND
OKLAHOMA TONIGHT IN ADVANCE OF AN UPPER LEVEL TROUGH OVER NORTHERN
UTAH. WEAK TO MODERATE INSTABILITY WILL COMBINE WITH VERY STRONG
WIND SHEAR TO PRODUCE SEVERE THUNDERSTORMS...SOME OF WHICH WILL BE
SUPERCELLS. VERY STRONG WINDS JUST ABOVE THE SURFACE MAY MIX TO THE
GROUND IN AND AROUND THE STRONGER STORMS TONIGHT. SOME AREAS ACROSS
NORTH CENTRAL OKLAHOMA RECEIVED VERY HEAVY RAINFALL LAST NIGHT AND
WILL REMAIN VERY SUSCEPTIBLE TO FLASH FLOODING TONIGHT.

PROBABILITY TABLE...
VALID THROUGH 500 AM CDT MONDAY APR 27.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR... 70 PERCENT.

OTHER HAZARDOUS WEATHER...
A FLOOD WATCH IS IN AFFECT FOR PARTS OF NORTHERN OKLAHOMA THROUGH
MONDAY AFTERNOON.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...

THUNDERSTORM OUTLOOK...
STRONG TO SEVERE THUNDERSTORMS ARE AGAIN POSSIBLE ON MONDAY AS THE
COLD FRONT MOVES SOUTH. A SLIGHT RISK OF SEVERE STORMS IS FORECAST
OVER CENTRAL AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS. A
BREAK IN THE ACTION IS EXPECTED ON TUESDAY...BUT THUNDERSTORMS WILL
LIKELY RESUME WEDNESDAY...WITH THE ACTIVE PATTERN REMAINING THROUGH
FRIDAY.

OTHER HAZARDOUS WEATHER...
RIVER FLOODING WILL OCCUR IN AREAS OF NORTHERN AND WESTERN OKLAHOMA
ON MONDAY AND TUESDAY AS A RESULT OF RECENT HEAVY RAINFALL. THOUGH
EXACT AREAS CANNOT BE DEFINED AT THIS POINT...MULTIPLE ROUNDS OF
HEAVY RAINFALL THROUGH NEXT THURSDAY COULD CAUSE FLOODING IN OTHER
AREAS OF OKLAHOMA AND NORTH TEXAS.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT 5 AM
MONDAY MORNING. UNSCHEDULED UPDATES MAY ALSO BE ISSUED SUNDAY
EVENING.

[Karried]

Across the screen about a half hour earlier it said Tornado possibility was Downgraded. Is that true?

[venture]

SPC says no, I would say yes.

[venture]

Quick thoughts on why so far things seem to not have gone...

1) Early convection was a major point and little cap/sun.
2) Supercells that did developed ended up training or going semi-linear really fast.

This is one of those cases that I've talked about, on high risk days if one little thing is out of whack...the whole event fails. So don't think of this as a blown forecast or that the guys got it wrong...one or two little things threw the whole thing off. Now should they still have a high risk up? No.

If the storms didn't line up like they did, they wouldn't have been seeding each other reducing their intensity. So pretty much, the potential was there...but a couple things were out of order and it didn't happen.

[Thunder]

Venture, I'm home now, but the chat is saying to be on standby mode.

I CAN'T TALK! lol

I didn't see much. Little rain, no hail, no tornado, frequent lightning.

[venture]

Power outage a few minutes ago, haven't been able to get it bakc up yet.

[Thunder]

Okay, I'll sit here and wait. lol

[Thunder]

Venture, this is probably nothing, but maybe you got an answer for this?



What is that circle? Just a random shape or something else? It made me think of the hurricane eye, but I know that isn't it. lol

[venture]

It could be a little meso low in the MCS...but that is just a rough guess without looking at anything.

Latest MCD from SPC say they are watching for development in Western/Central OK.