April 26th-30th, 2014 Major Tornado Outbreak

[janetjanet998]

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0751 AM CDT SUN APR 27 2014  
 
VALID 271300Z - 281200Z  
 
...THERE IS A MDT RISK OF SVR TSTMS OVER FAR ERN PARTS OF  
KS/OK...NERN TX...AR...WRN/CNTRL/SRN MO...NWRN MS AND WRN TN...  
 
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO VALLEY TO ERN  
TX AND THE LOWER MS VALLEY...  
   
..SUMMARY  
 
WIDESPREAD SEVERE THUNDERSTORMS CAPABLE OF TORNADOES...VERY LARGE  
HAIL AND DAMAGING WINDS ARE LIKELY FROM THE MIDDLE AND LOWER  
MISSOURI VALLEY SOUTH THROUGH THE OZARKS INTO LOWER MISSISSIPPI  
VALLEY THIS AFTERNOON INTO TONIGHT. THE GREATEST RISK FOR A FEW  
INTENSE TORNADOES WILL EXIST ACROSS MUCH OF ARKANSAS PERHAPS INTO  
WESTERN AND CENTRAL MISSOURI THIS AFTERNOON INTO TONIGHT.  
   
..SYNOPSIS  
 
A POWERFUL SHORT-WAVE TROUGH AND ASSOCIATED 70-80 KT MIDLEVEL JET  
STREAK WILL TRANSLATE FROM THE CNTRL/SRN HIGH PLAINS INTO THE UPPER  
MIDWEST WITH THE SYSTEM CLOSING OFF AN UPPER LOW OVER THE CNTRL  
PLAINS. ON THE HEELS OF THE INITIAL SHORT-WAVE TROUGH...A CHANNELED  
VORTICITY MAXIMUM AND ATTENDANT 70+ KT JET STREAK AT 500 MB WILL  
PROGRESS THROUGH THE SRN PLAINS INTO THE OZARK PLATEAU BY TONIGHT.  
IN RESPONSE TO THIS UPPER-AIR PATTERN EVOLUTION...A 40-50+ KT SLY  
LLJ WILL MIGRATE FROM ERN PARTS OF THE GREAT PLAINS INTO MS  
VALLEY...ENHANCING THE POLEWARD FLUX OF HEAT AND MOISTURE THROUGH  
THE WARM SECTOR OF THE SYNOPTIC CYCLONE.  
 
AT THE SURFACE...A LEE CYCLONE OVER SWRN NEB WILL GRADUALLY FILL AS  
IT SLOWLY DEVELOPS ENEWD INTO ERN NEB BY 28/12Z. A TRAILING PACIFIC  
FRONT WILL SURGE EWD THROUGH THE CNTRL PLAINS INTO OZARKS/OZARK  
PLATEAU WITH THE SRN EXTENSION OF THE FRONT MOVING MORE SLOWLY EWD  
THROUGH CNTRL INTO ERN TX. MEANWHILE...A WARM FRONT WILL STEADILY  
MOVE NWD THROUGH THE LOWER/MID MO AND MID MS VALLEYS.  
 
...SRN PLAINS INTO THE LOWER MS VALLEY THIS MORNING THROUGH  
TONIGHT...  
 
TSTMS HAVE RECENTLY DEVELOPED ALONG AND JUST AHEAD OF THE PACIFIC  
FRONT OVER OK/N TX ALONG THE SRN FRINGE OF STRONGER HEIGHT  
FALLS/DCVA ATTENDANT TO THE SHORT-WAVE PROGRESSING NEWD INTO THE  
CNTRL PLAINS. THESE STORMS ARE LIKELY SLIGHTLY ELEVATED AND ROOTED  
WITHIN A MOIST WARM CONVEYOR BELT AIR STREAM WHICH COINCIDES WITH  
STEEP MIDLEVEL LAPSES AND MUCAPE OF 2000-2500 J/KG. AREA VAD DATA  
INDICATE A VEER-BACK SIGNATURE WITH HEIGHT WHICH SHOULD YIELD  
COMPLEX STORM MODES CAPABLE OF MAINLY LARGE HAIL AND LOCALLY  
DAMAGING WINDS AS ACTIVITY SHIFTS NEWD THIS MORNING.  
 
A SUBSET OF THE ONGOING STORMS WILL LIKELY BECOME SURFACE-BASED BY  
LATE MORNING INTO AFTERNOON OVER ERN OK INTO NERN TX WITH OTHER IN  
SITU STORM DEVELOPMENT ALONG THE FRONT. ADDITIONAL TSTMS ARE  
ANTICIPATED BY AFTERNOON AHEAD OF THE FRONT FROM THE ARKLATEX NEWD  
ACROSS AR...IN THE WAKE OF THE MORNING ELEVATED STORMS. BOTH THESE  
REGIMES WILL BE ENCOURAGED BY THE ARRIVAL OF THE NEXT MIDLEVEL JET  
STREAK PROPAGATING THROUGH THE RED RIVER VALLEY.  
 
THE COMBINATION OF MODERATE INSTABILITY AND RELATIVELY STRONG  
VERTICAL SHEAR WILL PROMOTE A MIXTURE OF SUPERCELL AND BOWING  
STRUCTURES CAPABLE OF TORNADOES...VERY LARGE HAIL AND DAMAGING  
WINDS. THE MOST FAVORABLE ENVIRONMENT FOR LONG-LIVED SUPERCELLS AND  
MULTIPLE INTENSE TORNADOES WILL LIKELY MATERIALIZE OVER AR TOWARD  
THE DELTA REGION OF NWRN MS LATER THIS AFTERNOON INTO TONIGHT.  
HERE...MLCAPE OF 2000-2500 J/KG WILL ALIGN WITH EFFECTIVE SRH OF  
250-350 M2/S2 AND 50-60 KT OF DEEP-LAYER SHEAR TO CREATE A VERY  
FAVORABLE ENVIRONMENT FOR UPDRAFT ROTATION. AN UPGRADE TO A  
CATEGORICAL HIGH RISK REMAINS POSSIBLE OVER THIS AREA LATER TODAY.  
   
..NEB/KS EWD INTO MID MS VALLEY LATE THIS MORNING INTO TONIGHT  
 
ELEVATED TSTMS HAVE GRADUALLY INCREASED IN COVERAGE EARLY THIS  
MORNING OVER THE CNTRL PLAINS ALONG THE LEADING EDGE OF HEIGHT FALLS  
ATTENDANT TO THE HIGH PLAINS SHORT-WAVE TROUGH...AND ROOTED WITHIN A  
BELT OF ISENTROPIC ASCENT ALONG THE NOCTURNAL LLJ. THIS ACTIVITY MAY  
CONTINUE TO INCREASE IN AREAL COVERAGE THIS MORNING WHILE MOVING  
NEWD INTO THE MID AND LOWER MO VALLEY. LARGE HAIL AND LOCALLY  
DAMAGING WIND GUSTS WILL BE THE PRIMARY HAZARDS WITH THESE STORMS.  
 
UNCERTAINTY IN DEGREE OF AFTERNOON DESTABILIZATION HAS INCREASED  
OVER THE LAST COUPLE OF HOURS OWING TO THE GROWING EXTENT OF  
ELEVATED TSTMS. WHERE BREAKS IN THE CLOUDS CAN OCCUR...CONTINUED  
BOUNDARY LAYER MOISTENING COUPLED WITH STRONG COOLING ALOFT WILL  
PROMOTE MLCAPE APPROACHING 1000-2000 J/KG. WHEN COUPLED WITH  
VERTICALLY VEERING WIND PROFILES AND 40-50 KT OF DEEP-LAYER  
SHEAR...THE ENVIRONMENT WILL BE SUPPORTIVE OF A MIXTURE OF BOWING  
AND SUPERCELL STRUCTURES CAPABLE OF TORNADOES /SOME POSSIBLY  
STRONG/...VERY LARGE HAIL AND DAMAGING WINDS. THE POTENTIAL FOR  
ISOLATED TORNADOES WILL EXIST AS FAR W/SW AS WRN NEB/NERN CO/NWRN KS  
INVOF THE DEEP-LAYER CYCLONE WHERE STEEP LAPSE RATES WILL COINCIDE  
WITH HIGH AMBIENT VERTICAL VORTICITY.  
 
BY THIS EVENING INTO TONIGHT...TSTMS MAY CONSOLIDATE INTO CLUSTERS  
OR A QLCS WITH THE RISK FOR PRIMARILY DAMAGING WINDS AND HAIL  
SPREADING EWD INTO THE MID MS VALLEY.  
 

[Disc]

90 contour showing up now.

 

[OUGrad05]

I am very surprised central and SW Ar didn't get an upgrade to high risk.  Not even that, but tor probs are 15%.  

It seems that there is a significant risk of tornadic activity from KC down to northern LA.  However, I'm wondering how much this morning convection will inhibit development, especially along the I44 corridor and to the north.  I think I would have carved out a high risk from Ft Smith, to Little Rock, down to Texarcana and El Dorado...

 

Over the next couple of hours I would suspect we'll see some of this activity in OK become surface based slowly as the storms progress eastward.  

[JoMo]

(Time Sensitive)

 

It's pretty cloudy west of here....

 

[OUGrad05]

JoMo it's pretty cloudy here in the Tulsa area no doubt.  Strong SE breeze at the moment and humidity sitting at 80%...

[NavarreDon]

 MESOSCALE DISCUSSION 0415   NWS STORM PREDICTION CENTER NORMAN OK   0903 AM CDT SUN APR 27 2014   AREAS AFFECTED...NORTH TEXAS   CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON    VALID 271403Z - 271430Z   PROBABILITY OF WATCH ISSUANCE...95 PERCENT   SUMMARY...A SEVERE TSTM WATCH WILL BE COORDINATED SHORTLY FOR PARTS   OF NORTH TEXAS AHEAD OF THE DEVELOPING LINE OF THUNDERSTORMS. SEVERE   HAIL AND WIND WILL BE THE MAIN THREATS.   DISCUSSION...ENVIRONMENTAL CONDITIONS HAVE BECOME FAVORABLE FOR   SEVERE STORMS AND A WATCH ISSUANCE WILL BE COORDINATED BETWEEN THE   SPC AND THE AFFECTED LOCAL NATIONAL WEATHER SERVICE OFFICES SHORTLY.   ..DEAN/DIAL.. 04/27/2014   ATTN...WFO...FWD...   LAT...LON   31339755 32439702 33199677 33489673 33729618 33809550               33639542 33539541 33169563 32959575 32639580 32299569               32029562 31739551 31579584 31229590 31139619 30989659               31049717 31339755 

[radarman]

 

 MESOSCALE DISCUSSION 0415   NWS STORM PREDICTION CENTER NORMAN OK   0903 AM CDT SUN APR 27 2014   AREAS AFFECTED...NORTH TEXAS   CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON    VALID 271403Z - 271430Z   PROBABILITY OF WATCH ISSUANCE...95 PERCENT   SUMMARY...A SEVERE TSTM WATCH WILL BE COORDINATED SHORTLY FOR PARTS   OF NORTH TEXAS AHEAD OF THE DEVELOPING LINE OF THUNDERSTORMS. SEVERE   HAIL AND WIND WILL BE THE MAIN THREATS.   DISCUSSION...ENVIRONMENTAL CONDITIONS HAVE BECOME FAVORABLE FOR   SEVERE STORMS AND A WATCH ISSUANCE WILL BE COORDINATED BETWEEN THE   SPC AND THE AFFECTED LOCAL NATIONAL WEATHER SERVICE OFFICES SHORTLY.   ..DEAN/DIAL.. 04/27/2014   ATTN...WFO...FWD...   LAT...LON   31339755 32439702 33199677 33489673 33729618 33809550               33639542 33539541 33169563 32959575 32639580 32299569               32029562 31739551 31579584 31229590 31139619 30989659               31049717 31339755 

 

Yeah a few broken cells entered the western edge of the DFW metro and congealed into a line very quickly.  I don't see it breaking up too much as it heads toward the radar hole and strengthens.  Anything that pops out front could rotate briefly before being overtaken and I could definitely see a QLCS or three, but with the exception of a cool shelf cloud the chase might be pretty lousy.

[Jim Marusak]

current radar in central and north-central texas. hail signatires all the way up and down i-35 from north of the metroplex to Crawford/Waco.

 

and looking at the obs down there real quick, how long until you think the 2nd line is in the offing down there given the dryline back still neat wichita falls/breckenridge?

[OceanStWx]

(Time Sensitive)

 

It's pretty cloudy west of here....

 

Morning SGF sounding.

 

But watch what happens with progged boundary layer heating/moistening (from 72/60 to 76/63) and cooling aloft. These are model forecast temps aloft so there could be some issues with convection ongoing, etc. But it will be close.

 

[UKStormFan]

First post. 

 

Living over in the UK at the moment, but I enjoy following things in this neck of the woods during tornado season, 

 

Struggled to find a decent American weather forum, which is strange given the magnitude of the country and the range of weather. 

 

Just a couple of questions - 

 

- Anywhere I can find live news covering this?

- Is there a weather channel stream anywhere around the block?

- Anyone in particular I should be following on Twitter/Facebook?

 

Cheers.

Stay safe everyone.

[tornadotony]

Yeah I'm not gonna lie...the southern half of that convective gives me only about 10% concern right now.  There's hardly any cold pool behind the storms, they're very cellular.  As they move east, if they stay this way, these bands will likely break apart into more discrete supercells as destabilization occurs and shear vectors become more perpendicular to the band orientation.  It also means that these cells likely won't destroy potential behind them, at least across far S MO and AR/LA.  Now that part of the line in KS has a better cold pool established behind it, so it's likely a different story up there.

[Derecho!]

First post.

Living over in the UK at the moment, but I enjoy following things in this neck of the woods during tornado season,

Struggled to find a decent American weather forum, which is strange given the magnitude of the country and the range of weather.

Just a couple of questions -

- Anywhere I can find live news covering this?

- Is there a weather channel stream anywhere around the block?

- Anyone in particular I should be following on Twitter/Facebook?

Cheers.

Stay safe everyone.

if there happens to be a local news station with an interesting stream at the moment it usually gets posted here. otherwise try Wikipedia and "list of television stations in Arkansas" (and the same for Missouri). ABC, CBS, NBC, and Fox stations may or may not have live continuous news streaming at any given time, on a link on their website. large cities like Little Rock will have all 4 networks, smaller towns may only have 1-2 of the networks, but they will all have their own local independent weather coverage.

This coverage varies widely in quality, and unfortunately stations in this area lack the dedicated chasers and tornado focus of stations in Oklahoma City. I'm not from the area but many posters on this thread are and they could likely comment on the best local stations for weather in Little Rock, Springfield, etc.

[Jim Marusak]

First post. 

 

Living over in the UK at the moment, but I enjoy following things in this neck of the woods during tornado season, 

 

Struggled to find a decent American weather forum, which is strange given the magnitude of the country and the range of weather. 

 

Just a couple of questions - 

 

- Anywhere I can find live news covering this?

- Is there a weather channel stream anywhere around the block?

- Anyone in particular I should be following on Twitter/Facebook?

 

Cheers.

Stay safe everyone.

first off, thanks for looking here for weather chat, where as most can agree here, when it comes to the nastiest of storm situations, this board does have a very diverse, but very informed set of posters. politics when the weather is calm can cause a lot of disagreement in here (in the off-topic section), but when it does come to weather information, this is one of the best places, imho to go for informed chat.

 

as for live news streams, you will see them posted from time to time, especially in the regional forums as local tv stations head into wall-to-wall coverage and open up streams. Last I knew the Weather Channel doesn't have a live stream online. but Weathernation does. and i'm wondering what will happen when accu-weather starts theirs in the fall. but when they are available, you'll see them posted.

 

and finally as for fb/twitter feeds, we'll probably have to get a list together one of these days of those who want to be followed on twitter and/or facebook for this. some people in here will post their handles on twitter, and i'm sure your following would be appreciated. but when you go onto their profiles and see who they're subscribed to, there's when you'll see who are the people to follow. there's a lot of good out there. just have to go with the more major places as well as who you're comfortable potentially talking to (especially when big winter and/or summer storms make their way to the UK and we might need some info from you).

[SmokeEater]

if there happens to be a local news station with an interesting stream at the moment it usually gets posted here. otherwise try Wikipedia and "list of television stations in Arkansas" (and the same for Missouri). ABC, CBS, NBC, and Fox stations may or may not have live continuous news streaming at any given time, on a link on their website. large cities like Little Rock will have all 4 networks, smaller towns may only have 1-2 of the networks, but they will all have their own local independent weather coverage.

This coverage varies widely in quality, and unfortunately stations in this area lack the dedicated chasers and tornado focus of stations in Oklahoma City. I'm not from the area but many posters on this thread are and they could likely comment on the best local stations for weather in Little Rock, Springfield, etc.

I'll post when live coverage comes available on here.

[Ed Lizard]

I doubt it happens in time for immediate DFW, but a quick check of obs, (oh, and satellite) the dryline is in the far Northwest part of the FWD CWA, the overcast doesn't seem that thick as temps are warming back into the 80s behind the initial line, and I am a bit of a homer, and DFW and points East (maybe to CLL and UTS) are as close as the action comes to my IMBY.

 

Big cap on 12Z FWD sounding, but maybe earlier elevated storms cooled and moistened it a little.  That may be wishful thinking.

[OUGrad05]

Storm to the SE of McAlister probably worth keeping an eye on, been slowl intensifying.

[janetjanet998]

AM CDT SUN APR 27 2014  
 
AREAS AFFECTED...EXTREME ERN KS THROUGH WRN MO AND SWRN IA  
 
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY  
 
VALID 271537Z - 271730Z  
 
PROBABILITY OF WATCH ISSUANCE...80 PERCENT  
 
SUMMARY...SEVERE POTENTIAL INCLUDING THE RISK FOR DAMAGING  
WIND...LARGE HAIL AND TORNADOES IS EXPECTED TO INCREASE FROM EXTREME  
ERN KS THROUGH WRN MO AND SWRN IA LATE THIS MORNING INTO THE  
AFTERNOON. A TORNADO WATCH WILL LIKELY BE NEEDED SOON.  
 
DISCUSSION...BROKEN LINE OF STORMS HAS DEVELOPED A COLD POOL AND IS  
MOVING EAST AT AROUND 25 KT. THE ATMOSPHERE EAST OF THE LINE IS  
MODERATELY UNSTABLE WITH STEEP LAPSE RATES...BUT THE BOUNDARY LAYER  
IS STILL CAPPED AND HAS NOT YET UNDERGONE SIGNIFICANT  
DESTABILIZATION. HOWEVER...SOME BREAKS ARE NOW EVIDENT WITHIN THE  
MULTILAYER CLOUDS ACROSS WRN MO AND THE SFC LAYER CONTINUES TO  
MOISTEN WITH DEWPOINTS RISING INTO THE LOW 60S ALONG THE SLY LLJ  
AXIS. DEEP LAYER WIND AND SHEAR PROFILES WILL INCREASE IN THIS  
REGION THIS AFTERNOON AS A MID-LEVEL JET ROTATES NEWD ALONG THE SERN  
PERIPHERY OF THE UPPER LOW LOCATED ACROSS WRN KS. THUS THE  
ENVIRONMENT WILL GRADUALLY BECOME MORE FAVORABLE FOR SEVERE STORMS.  
WHILE CONVECTIVE MODE IS NOT CURRENTLY FAVORABLE FOR MORE WIDESPREAD  
TORNADO ACTIVITY...SOME CHANGE IN CHARACTER OF THE STORMS MAY OCCUR  
WITH POTENTIAL FOR EMBEDDED SUPERCELL STRUCTURES AS THE BOUNDARY  
LAYER CONTINUES TO DESTABILIZE AND DEEP LAYER WINDS STRENGTHEN.  
 
..DIAL/THOMPSON.. 04/27/2014  
   
 

[wxmeddler]

First post. 

 

Living over in the UK at the moment, but I enjoy following things in this neck of the woods during tornado season, 

 

Struggled to find a decent American weather forum, which is strange given the magnitude of the country and the range of weather. 

 

Just a couple of questions - 

 

- Anywhere I can find live news covering this?

- Is there a weather channel stream anywhere around the block?

- Anyone in particular I should be following on Twitter/Facebook?

 

Cheers.

Stay safe everyone.

 

Welcome! We always enjoy visitors from across the pond.

 

To answer your questions

- Local TV stations will activate live streams once tornado warnings start being issued, usually someone on here gives a link. Otherwise you can just google "Little Rock TV Live" or something like that and see if they have a stream active.

 

- Not that are legal, perhaps the Weather Network might have one that is free but I'm not sure.

 

- @@jimcantore, @@ustornadoes, @@spann

Also, almost all weather related tweets use the hashtag #(state abbreviation)wx, for example Arkansas would be #arwx and Missouri would be #mowx

[OUGrad05]

Temps dropped 15 degrees in about 10 min here at my house.

Lots of great cloud motions capture the potential further East.

Sent from my SM-N900V

[UKStormFan]

I wont, clog up the forum quoting 3 or 4 people, but I'll refer to you all in here. 

 

Thanks for the warm welcome, guidance and direction on where to look next! 

 

I've been lurking around here and always find the US climate to be incredible, it makes our 'eratic' climate look so boring.

 

I'll be searching for some stuff on Twitter and google for the rest and the next couple of days! 

 

Just a couple more questions... is there any sort of 'live chat' feature on the website where people discuss things in real time?! I always find the most interesting form of following the weather to be watching a live channel as they break things down in real time! Lastly, do we have any real time free radars? 

 

Cheers again guys.

[CT Rain]

Looks like skies are clearing pretty quickly in central and southern AR. I think most of AR is primed for an ugly outbreak. 

[andyhb]

Looking at satellite/radar trends, it's pretty obvious that the convection further south along the dryline in S OK and TX (that would go on to impact AR) is weakening substantially.

 

Judging by the fact that we already have upper 60s dew points over most of the region, LCL heights certainly won't be a big issue here.

[Santa Clause]

AR looks primed, some sun is beginning to break through and it's right on time too. Not sure things will become anything other than linear further to the N though..

[Chicago Storm]

Currently north of Newton, KS.

CU field has quickly developed along/ahead of the dryline in C. KS. Environment is worked over though based on meso-analysis. We'll see how quickly things destabilize in the axis behind the storms to the east and the DL.

[tornadotony]

Looking at satellite/radar trends, it's pretty obvious that the convection further south along the dryline in S OK and TX (that would go on to impact AR) is weakening substantially.

 

Judging by the fact that we already have upper 60s dew points over most of the region, LCL heights certainly won't be a big issue here.

Whatever remains of that convective line will likely serve as a confluence zone for numerous supercells this afternoon.

[andyhb]

Up to 81/68 at ELD.

[Chicago Storm]

Currently north of Newton, KS.

CU field has quickly developed along/ahead of the dryline in C. KS. Environment is worked over though based on meso-analysis. We'll see how quickly things destabilize in the axis behind the storms to the east and the DL.

CU field is agitated, with nice vertical growth.

[CoastalWx]

Looks like skies are clearing pretty quickly in central and southern AR. I think most of AR is primed for an ugly outbreak. 

 

That area looks pretty impressive right now.

[andyhb]

On a sidenote, holy moly at the 12z GFS for Tuesday, >70 kts of 0-6 km shear over the northern half of AL.

[TheWeatherPimp]

First tornado watch of the day issued for Eastern Kansas, Western Missouri and Southern Iowa.