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Sat Apr 14, 2012, 02:41 AM

Life Threatening Tornado Outbreak For OKC, Wichita, Omaha Saturday - Please k/r for wide visibility

TO THE MODS: I have posted weatherdude's post in it's entirety because I am certain he wants this information disseminated far and wide. Thank you

Life Threatening Tornado Outbreak For OKC, Wichita, Omaha Saturday (New Diary Posted)
by weatherdude

A new diary was posted at 1130 PM CDT talking about the Friday evening model runs and what they mean for the Saturday tornado outbreak.

843PM CT: Once the 00z (700PM CT) model runs come out, I'll write up another diary on this situation.

554PM CT: I changed the title because of some confusion over what the abbreviations meant.

UPDATE 1255PM CT: I've updated to show the latest SPC forecast. The SPC has expanded the high risk/60% zone into parts of Nebraska and Iowa, to include the cities of Omaha, Lincoln, and Norfolk NE. Anyone in the red MDT (moderate) risk zone, and especially in the purple HIGH risk zone, needs to be alert for a major, intense tornado outbreak tomorrow. The environment is capable of supporting EF-4 to EF-5 tornadoes in the moderate risk zone, and especially in the high risk zones. That's why I'm sounding so Chicken Little-y about this. This has the makings to be a very dangerous outbreak, so please alert those you know about the situation and keep a close eye on the weather over the next 48 hours.

PS -- What I mean by "unprecedented" is that the forecast itself is unprecedented, not necessarily the outbreak. [strike]The SPC has, as far as I know, never issued a high risk zone 3 full days in advance of a tornado outbreak, and they've definitely never issued a 60% risk zone for severe weather.[/strike] Their certainty in this forecast is unprecedented, but in a good way (in that they're getting the word out really early).

They've done this once before on April 6, 2006 for a major tornado outbreak across parts of the southeast. There was also a 60% severe weather risk on that day. The resulting outbreak produced 94 tornado reports, 215 wind damage reports, and 565 hail reports.

PPS -- The tornadoes occurring this evening across Oklahoma are not part of the outbreak mentioned in this diary. The last week or so has been one long severe weather episode across this part of the country, which will come to a head tomorrow with the outbreak mentioned below. The threat will shift east on Sunday.


A major severe weather outbreak is expected across the Central Plains on Saturday afternoon and evening, with an absolutely unprecedented severe weather forecast coming from the Storm Prediction Center. A full two days before the outbreak, the SPC has issued a high risk for severe weather across parts of Oklahoma and Kansas, including the Oklahoma City metro area, as well as Wichita KS.



With extremely strong shear and relatively high amounts of CAPE forecast to be in place on Saturday, any storms that fire from Texas to Iowa are expected to turn quickly severe, with the worst weather occurring over central parts of Oklahoma and Kansas. Helicity -- a measure of spin that can occur inside of a thunderstorm -- is off the charts in this area. As of the model runs at 8PM last night, the helicity in Wichita KS was near 750. A value of 450 is sufficient for violent EF-4 to EF-5 tornadoes to develop.

The SPC is so confident that very dangerous severe weather will occur, that not only have they issued a high risk an unprecedented 2 days in advance, but they've also issued a 60% risk for severe weather, another absolutely unprecedented forecast. Not even during the strongest ongoing severe weather have I seen them issue a 60% risk zone.



I typed this diary at 125AM Central Time, and scheduled it to post at 900AM. I'm likely still sleeping by the time this diary posted, but I wanted to get the word out now that a very dangerous, life-threatening situation is expected to develop on Saturday. If you or anyone you know lives in the area under any threat for severe weather (within the yellow, red, or purple shading), let them know to keep a hawk-like watch on the weather today and tomorrow.

I'll have another diary later this evening on the outbreak, and definitely throughout the day tomorrow.

Here's a link to the Storm Prediction Center - http://www.spc.noaa.gov/.

NWS Oklahoma City - http://www.srh.noaa.gov/oun/
NWS Wichita KS - http://www.crh.noaa.gov/ict/
NWS Dallas/Fort Worth - http://www.srh.noaa.gov/fwd/
NWS Topeka KS - http://www.crh.noaa.gov/top/
NWS Omaha, NE - http://www.crh.noaa.gov/oax/

http://www.dailykos.com/story/2012/04/13/1083015/-Unprecedented-Severe-Weather-Forecast-Life-Threatening-Situation-For-OKC-Wichita-Saturday

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Reply Life Threatening Tornado Outbreak For OKC, Wichita, Omaha Saturday - Please k/r for wide visibility (Original post)
FourScore Apr 2012 OP
elleng Apr 2012 #1
Arctic Dave Apr 2012 #2
longship Apr 2012 #3
MadHound Apr 2012 #4
KatyaR Apr 2012 #5

Response to FourScore (Original post)

Sat Apr 14, 2012, 02:43 AM

1. Kick

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Response to FourScore (Original post)

Sat Apr 14, 2012, 02:55 AM

2. K&R

 

Stay safe everybody.

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Response to FourScore (Original post)

Sat Apr 14, 2012, 06:47 AM

3. Kick

As a former Wichita resident, I worry for my friends.

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Response to FourScore (Original post)

Sat Apr 14, 2012, 06:54 AM

4. Here in Mid Mo it's been raining since late Thursday night,

 

Had a major line come through early this morning, hail, lots of lighting, and lots of rain. We'll see what the rest of the day brings.

I'm actually happy we're getting this rain, we need it. The tornadoes, not so much.

Everybody stay safe out there, and close to a hole in the ground.

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Response to FourScore (Original post)

Sat Apr 14, 2012, 10:10 AM

5. Big kick for OKC.

We've had storms ongoing since late yesterday afternoon, a few tornadoes, lots of rain and wind. I'm staying close to home today, that's for sure.

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