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Fri Apr 13, 2012, 03:52 AM

Tornado outbreak likely in the Plains this weekend?

Well, ladies and gents, it's that time of year again, where one day it's nice and sunny and pouring cats & dogs the next.

I'm a bit of a weather watcher and I have been keeping a good eye on this next potential event for several days now.
Apparently, the National Weather Service is starting to become a little concerned; the SPC in Norman recently issued a High Risk for severe weather for much of central Okla. and southern Kan. The Moderate Risk zone stretches all the way from Abilene to Omaha and Des Moines, IA.

http://www.spc.noaa.gov/products/outlook/day2otlk.html


DAY 2 CONVECTIVE OUTLOOK RESENT 1
NWS STORM PREDICTION CENTER NORMAN OK
0102 AM CDT FRI APR 13 2012

VALID 141200Z - 151200Z

...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF OK AND KS...

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NW TX...CNTRL
AND WRN OK...CNTRL AND ERN KS...SE NEB...NW MO AND FAR SW IA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID-MO
VALLEY...UPPER MS VALLEY...SRN PLAINS AND CNTRL PLAINS...

TORNADO OUTBREAK LIKELY ACROSS THE SRN AND CNTRL PLAINS NWD INTO THE
MID-MO VALLEY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT

...SRN AND CNTRL PLAINS...
AN IMPRESSIVE UPPER-LEVEL LOW WILL MOVE EWD ACROSS FOUR CORNERS
REGION SATURDAY AS A POWERFUL 90 TO 110 KT MID-LEVEL JET EJECTS NEWD
INTO THE SRN AND CNTRL PLAINS. AHEAD OF THE SYSTEM...A CORRIDOR OF
MODERATE TO STRONG INSTABILITY IS FORECAST ACROSS ECNTRL KS...CNTRL
OK INTO NW TX. THIS COMBINED WITH STEEP MID-LEVEL LAPSE RATES AND
STRONG LOW-LEVEL SHEAR WILL BE VERY FAVORABLE FOR SEVERE STORMS AND
A TORNADO OUTBREAK WILL BE LIKELY ACROSS THE SRN AND CNTRL PLAINS
FROM LATE SATURDAY AFTERNOON LASTING THROUGH THE EVENING AND INTO
THE OVERNIGHT PERIOD.

NAM AND NAMKF FORECAST SOUNDINGS AT 00Z SATURDAY EVENING FROM SALINA
KS SWD TO AROUND OKLAHOMA CITY SHOW MLCAPE VALUES FROM 2000 TO 3000
J/KG WITH 0-6 KM SHEAR IN THE 60 TO 75 KT RANGE. IN
ADDITION...HODOGRAPHS ARE LARGE AND LOOPED WITH 0-1 KM SHEAR VALUES
IN THE 30 TO 40 KT RANGE. THIS ENVIRONMENT SHOULD BE VERY FAVORABLE
FOR SUPERCELLS AND TORNADOES. 0-3 KM STORM RELATIVE HELICITIES ARE
FORECAST TO BE AROUND 400 M2/S2 WHICH IS IDEAL FOR STRONG TORNADOES
AND A TORNADO OUTBREAK APPEARS LIKELY. THE GREATEST THREAT FOR
SIGNIFICANT TORNADOES SHOULD EXIST SATURDAY EVENING FROM SALINA SWD
TO OKLAHOMA CITY. 700 TO 500 MB LAPSE RATES AROUND 7.5 C/KM WILL
ALSO BE FAVORABLE FOR LARGE HAIL AND HAIL GREATER THAN 2 INCHES WILL
BE POSSIBLE THE MORE INTENSE SUPERCELLS. A WIND DAMAGE THREAT WILL
ALSO EXIST DUE TO THE EXPECTED INTENSE NATURE OF THE STORMS.

THE MAIN CONCERN FOR THIS FORECAST IS CONVECTIVE COVERAGE. MANY OF
THE MODELS DO NOT DEVELOP NUMEROUS THUNDERSTORMS ALONG THE DRYLINE.
IN SPITE OF THIS...THE MODELS DIMINISH THE CAP ACROSS THE SRN AND
CNTRL PLAINS LATE SATURDAY AFTERNOON SO THIS BRINGS THE MODELS INTO
QUESTION. IN ADDITION...THE MODELS DRIVE A BAND OF LARGE-SCALE
ASCENT ACROSS CNTRL KS DURING THE EARLY EVENING SUGGESTING MANY
STORMS SHOULD INITIATE WITH STORMS INITIATING SWD WITH TIME EARLY
SATURDAY EVENING AS THE LOW-LEVEL JET STRENGTHENS. THESE FACTORS
COMBINED WITH SFC DEWPOINTS IN THE LOWER TO MID 60S F AND VERY
FAVORABLE LOW-LEVEL SHEAR PROFILES SHOULD PRODUCE AND ENVIRONMENT
FAVORABLE FOR A TORNADO OUTBREAK. AFTER COLLABORATION WITH WFOS
WICHITA...NORMAN...TOPEKA...TULSA AND DODGE CITY...A HIGH RISK WILL
BE ISSUED DUE TO THE POTENTIAL FOR A HIGH-END LIFE THREATENING EVENT
ACROSS THE SRN AND CNTRL PLAINS.

...MID-MO VALLEY/UPPER MS VALLEY...
AN IMPRESSIVE UPPER-LEVEL LOW WILL MOVE ACROSS THE FOUR CORNERS
REGION SATURDAY. AT THE SFC...A LOW SHOULD MOVE ACROSS NEB WITH A
WARM FRONT EXTENDING EWD ACROSS IA. THUNDERSTORMS SHOULD BE ONGOING
ALONG THIS BOUNDARY WITH STORMS EXPANDING NWD INTO THE UPPER MS
VALLEY. SOUTH OF THE BOUNDARY...THE MODELS DEVELOP MODERATE
INSTABILITY WITH A DRYLINE LOCATED IN ECNTRL NEB. THUNDERSTORMS THAT
INITIATE ALONG THE DRYLINE AND EWD ACROSS THE WARM SECTOR WILL
LIKELY HAVE AN ENHANCED SEVERE THREAT. STRONG DEEP LAYER SHEAR AND
ENHANCED LOW-LEVEL SHEAR WILL BE FAVORABLE FOR SUPERCELLS AND
TORNADOES. A FEW STRONG TORNADOES MAY OCCUR WITH THE MORE DOMINANT
SUPERCELLS ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS SATURDAY
EVENING. ALTHOUGH A TORNADO OUTBREAK WILL BE POSSIBLE ACROSS PARTS
OF THE REGION...THE GREATEST MOISTURE RETURN SHOULD REMAIN FURTHER
TO THE SOUTH SUGGESTING THE HIGHEST TORNADO THREAT SHOULD EXIST
ACROSS SERN NEB...SW IA...NW MO AND ERN KS WHERE A MODERATE RISK IS
LOCATED.

...NW TX/WCNTRL TX...
AN IMPRESSIVE UPPER-LEVEL LOW WILL MOVE EWD ACROSS THE FOUR CORNERS
REGION AND INTO THE HIGH PLAINS SATURDAY EVENING. MODEL FORECASTS
DEVELOP THUNDERSTORMS ALONG A WELL-DEFINED DRYLINE DURING THE
EVENING FROM WRN OK SSWWD ACROSS NW TX INTO WCNTRL TX. FORECAST
SOUNDINGS SATURDAY EVENING ALONG THIS CORRIDOR SHOW MODERATE
INSTABILITY...STRONG DEEP LAYER SHEAR AND STEEP MID-LEVEL LAPSE
RATES WHICH SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL.
SUPERCELLS SHOULD BE CAPABLE OF PRODUCING 2 INCH OR GREATER HAIL DUE
TO THE THERMODYNAMIC PROFILE. STRENGTHENING LOW-LEVEL SHEAR DURING
THE EVENING SHOULD ALSO RESULT IN A TORNADO THREAT AS WELL.

..BROYLES.. 04/13/2012


From what it looks like now, Dallas/Ft. Worth and Austin are mostly safe for now(though early afternoon storms are forecast)......though I'm not certain if that will remain the case.

Stay safe, everybody. This could be a very rough weekend.

14 replies, 1844 views

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Replies to this discussion thread
Arrow 14 replies Author Time Post
Reply Tornado outbreak likely in the Plains this weekend? (Original post)
AverageJoe90 Apr 2012 OP
Behind the Aegis Apr 2012 #1
Ecumenist Apr 2012 #2
Behind the Aegis Apr 2012 #3
YellowRubberDuckie Apr 2012 #9
AverageJoe90 Apr 2012 #4
malaise Apr 2012 #5
BadgerKid Apr 2012 #6
AverageJoe90 Apr 2012 #7
YellowRubberDuckie Apr 2012 #8
AverageJoe90 Apr 2012 #10
uppityperson Apr 2012 #11
cr8tvlde Apr 2012 #12
countryjake Apr 2012 #13
YellowRubberDuckie Apr 2012 #14

Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 04:11 AM

1. I am not looking forward to this weekend.

I still don't have the garage cleaned out and can't get the cars in there. I am hoping the hail, should it come, isn't large. Such is life in Oklahoma.

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Response to Behind the Aegis (Reply #1)

Fri Apr 13, 2012, 04:42 AM

2. Boy, Aegis, you're on Oklahoma? M mother's family is from Tulsa... Where are you?

btw, please stay safe. I reallyl like you and always look forward to reading your view on any topic. I will light a candle for you....May any storm scoot around you..

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Response to Ecumenist (Reply #2)

Fri Apr 13, 2012, 04:54 AM

3. I am north of Tulsa.

I just took the puppies out for their "morning" constitutional (the youngest just turned one year old today). The wind is already picking up, but I couldn't smell any rain because a skunk shot his load somewhere near my house. I will charge up the emergency radio and place flashlights in places without the special night lights (they are emergency lights that stay lit in a blackout). Thankfully, we had the dead tree removed this week. Damn, I am being way too chatty. LOL!

Thank you for such a sweet response. BTW, I like you too. You speak your mind, much the way I do. heehee.

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Response to Behind the Aegis (Reply #3)

Fri Apr 13, 2012, 07:22 PM

9. Glad you're prepared.

Fellow Okie here in OKC. They're coming up the Turner right to you. Stay safe!

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Response to Behind the Aegis (Reply #1)

Fri Apr 13, 2012, 08:23 AM

4. We had a close call with hail this last Tuesday after storms moved thru our area.......

Not only did we have to move our Honda into the garage but we actually had to take shelter.....and we lost our power for about 3 hours afterwards......not fun, but at least we came thru that okay.

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 08:29 AM

5. Let's get this to the greatest page for visibility n/t

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 11:42 AM

6. Very serious indeed

Last edited Fri Apr 13, 2012, 12:15 PM - Edit history (1)

The weather boards are pointing out that it is highly unusual for the NWS to issue a High Risk one day in advance. (Arguably reasonable, IMO.)

After the tornado destruction last April (Tuscaloosa may come to mind for some people), the meteorologists have apparently taken steps to get more information out there earlier.

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Response to BadgerKid (Reply #6)

Fri Apr 13, 2012, 07:19 PM

7. Sounds reasonably plausible to me, IMO.

The one bit of good news I've heard is that the La Nina may be starting to weaken by the end of this month.

I just hope there isn't another Joplin or Tuscaloosa event this year.

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 07:21 PM

8. Meteorologists friends of friends are bugging and emailing their friends.

Apparently even they are worried. Conditions are so unstable, one warning said people are going to die. They aren't being melodramatic. We are people who have lived through several EF5 tornadoes.
I'm in Oklahoma. I'll keep you guys as updated as I can.
Local live shots and coverage at News 9's website

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Response to YellowRubberDuckie (Reply #8)

Fri Apr 13, 2012, 07:44 PM

10. All the weather watcher DUers, especially your fellow Sooners, would appreciate that, I'm sure.

And it looks like I'll have to be extra watchful for inclement weather on Sunday myself. I live just north of Dallas and we're liable to get hit sometime between late morning and mid-afternoon from what I've heard so far. Not good, because my sleep schedule's been horribly messed up. =(

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 08:09 PM

11. Friend in Norman, OK had F2 come through town today. Damage and injuries but no deaths so far.

Best of luck to all in tornado lands.

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 08:48 PM

12. Seminole County Oklahoma SE OKC ... just a bit of wind...nothing else. n/t

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 09:02 PM

13. K&R!

Everybody stay safe!

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Response to AverageJoe90 (Original post)

Fri Apr 13, 2012, 09:14 PM

14. More Tornado warnings in SW OK...

They are moving EXTREMELY SLOW. 15-20 MPH. Stay safe and if you have family and friends here, please get in touch if you can. These are deadly and SLOW.
Stay safe!

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