April 26th-30th, 2014 Major Tornado Outbreak

[andyhb]

Alright, with that said, here goes nothing.

 

For tomorrow, there's no two ways around it, AR and vicinity is literally right in the firing line for significant/long-tracked tornadoes, including an extremely high nocturnal threat. All of the high-res guidance is in agreement with this (sustained supercells for a long period of time), with the low level shear absolutely exploding as the LLJ rapidly strengthens towards 00z (or even before for that matter) and the surface winds back very strongly, in addition to plenty of instability/moisture. I'm basically expecting a high risk to be issued for a sizable chunk of the current moderate risk at the 06z update because of this. In addition to that, the threat further north along the dryline to the warm front cannot be discounted either, as the SREF (and several high res models) has been hitting this area too quite hard. Storm mode will obviously be in question, but any supercells that do manage to become longer lasting will have potential for significant severe. I won't be too surprised if the moderate risk area is expanded substantially northward to account for this.

 

Obviously with Monday and Tuesday, there are questions about antecedent convection, but as several have mentioned across the different weather forums, the setup here will favour morning convection moving rather rapidly out of the primary threat areas, which may limit any negative effects on destabilization (in addition to potential outflow boundary generation/etc). The models also continue to show strong moisture surges with upper 60s/70s dews becoming entrenched over large areas on the respective days (both days also have substantial potential up into the GL/OV region as well as the moisture surges northward and upper support increases over a large area). This combined with several vort maxes rotating around the painfully slow moving parent upper trough should yield new development for both days, which also will spur on development of secondary surface lows as the Euro has been hinting for ~8 or more runs in a row now. This should serve to cause strengthening of the LLJ and backing of the surface winds to the S/SSE, which will obviously enhance low level/directional shear with already strong speed shear through the column. Combining these elements with the broad nature of the trough strongly suggests fast moving supercells will be the mode of choice for at least a decent period on both days, capable of significant tornadoes. It also suggests that any bowing segments/QLCS development will likely be full of embedded LEWPs, book-end vortices and supercells.

 

I have a feeling we're going to be exhausted at the end of this one, folks.

[janetjanet998]

low topped supercells may form by noon over NE in the cold core region with arcs of them(more classic type) developing south as the day goes on

 

there could be several spokes of them

 

I have seen tornado warnings issued by 10am in similar set ups in April starting near the low

[Disc]

KLIT is the bullseye in regards to.. well everything right now.

 

[hm8]

[JoMo]

Alright, with that said, here goes nothing.

 

For tomorrow, there's no two ways around it, AR and vicinity is literally right in the firing line for significant/long-tracked tornadoes, including an extremely high nocturnal threat. All of the high-res guidance is in agreement with this (sustained supercells for a long period of time), with the low level shear absolutely exploding as the LLJ rapidly strengthens towards 00z (or even before for that matter) and the surface winds back very strongly, in addition to plenty of instability/moisture. I'm basically expecting a high risk to be issued for a sizable chunk of the current moderate risk at the 06z update because of this. In addition to that, the threat further north along the dryline to the warm front cannot be discounted either, as the SREF (and several high res models) has been hitting this area too quite hard. Storm mode will obviously be in question, but any supercells that do manage to become longer lasting will have potential for significant severe. I won't be too surprised if the moderate risk area is expanded substantially northward to account for this.

 

Obviously with Monday and Tuesday, there are questions about antecedent convection, but as several have mentioned across the different weather forums, the setup here will favour morning convection moving rather rapidly out of the primary threat areas, which may limit any negative effects on destabilization (in addition to potential outflow boundary generation/etc). The models also continue to show strong moisture surges with upper 60s/70s dews becoming entrenched over large areas on the respective days (both days also have substantial potential up into the GL/OV region as well as the moisture surges northward and upper support increases over a large area). This combined with several vort maxes rotating around the painfully slow moving parent upper trough should yield new development for both days, which also will spur on development of secondary surface lows as the Euro has been hinting for ~8 or more runs in a row now. This should serve to cause strengthening of the LLJ and backing of the surface winds to the S/SSE, which will obviously enhance low level/directional shear with already strong speed shear through the column. Combining these elements with the broad nature of the trough strongly suggests fast moving supercells will be the mode of choice for at least a decent period on both days, capable of significant tornadoes. It also suggests that any bowing segments/QLCS development will likely be full of embedded LEWPs, book-end vortices and supercells.

 

I have a feeling we're going to be exhausted at the end of this one, folks.

 

Excellent write-up. I'm already exhausted from worrying about tomorrow. 

[B.Sebo]

Excellent write-up. I'm already exhausted from worrying about tomorrow. 

 

You ain't the only one, brother!

[andyhb]

Good grief, even the GFS and its crummy resolution is putting out an outbreak of supercells tomorrow evening.

[NCsandhills]

You guys I am seriously worried for my mom in Cabot tomorrow. It seriously looks to be right in the bulls-eye. I have already warned her and told her to keep her phone handy tomorrow because I'll be "tracking" the storms (by that I mean mainly following here, twitter and GRanalyst lol). 

 

Thank you for the information, y'all...it is super helpful, and I am helping to communicate the severity of tomorrow's situation via my FB account...which has tons of central AR folk. Hopefully people in AR are aware and taking this seriously. But, my experience in central Ark. says they are not. :/

[Jim Marusak]

You guys I am seriously worried for my mom in Cabot tomorrow. It seriously looks to be right in the bulls-eye. I have already warned her and told her to keep her phone handy tomorrow because I'll be "tracking" the storms (by that I mean mainly following here, twitter and GRanalyst lol). 

 

Thank you for the information, y'all...it is super helpful, and I am helping to communicate the severity of tomorrow's situation via my FB account...which has tons of central AR folk. Hopefully people in AR are aware and taking this seriously. But, my experience in central Ark. says they are not. :/

 

if there is a chance people there will take your advice, they will listen to one of their own, like you, compared to others. especially since you know the challenges of talking to them and getting the message across.

 

i know when severe weather or big winter storms are possible back in eastern PA where a lot of friends and family are, they trust me a lot more than any of the local TV mets, not only because i was their HS weatherman, but because I can talk their language and push the right buttons to have them take action.

 

as long as you did the best your could in explaining things in term you know they can understand, you did/are doing what you can. that's all you can do. something that i know all too well, but even when you try to live by that you can still be a big worry wart, but for good reason.

[Ozarkwx]

Yeah well, this is the first time since 5/4/03 I have had more than minor concerns about an upcoming event.  I know this is probably paranoid, but I am even considering video taping the contents of the house for insurance purposes in the morning.  (Probably a good idea since I have never done it.)  

 

What concerns me about this area is that there is a common belief that the Ozark "mountains" are inhospitable to tornadoes.  That plus tornadoes "don't like" Beaver Lake.  Thus, no tornado sirens needed here. 

[wxmeddler]

Not tomorrow related, This is back on the TX/NM line at Clovis AFB, but worth mentioning. No TS nearby just outflow.

SPECI KCVS 270402Z AUTO 31043G71KT 4SM TS HZ SQ FEW004 23/M08 A2951 RMK AO2 $

[janetjanet998]

Not tomorrow related, This is back on the TX/NM line at Clovis AFB, but worth mentioning. No TS nearby just outflow.

SPECI KCVS 270402Z AUTO 31043G71KT 4SM TS HZ SQ FEW004 23/M08 A2951 RMK AO2 $

 

very interesting feature and showing up on radar all over NW texas...some sort of wind shift line

[JoMo]

Yeah well, this is the first time since 5/4/03 I have had more than minor concerns about an upcoming event.  I know this is probably paranoid, but I am even considering video taping the contents of the house for insurance purposes in the morning.  (Probably a good idea since I have never done it.)  

 

What concerns me about this area is that there is a common belief that the Ozark "mountains" are inhospitable to tornadoes.  That plus tornadoes "don't like" Beaver Lake.  Thus, no tornado sirens needed here. 

 

That's probably a good idea, as long as you remember to take it with you and you have a safe place to go. The 'folklore' gives people a false sense of security. People thought that tornadoes wouldn't get near I-44 for some reason and that they 'always go north' of here. You do have a weather radio, right?

[OKpowdah]

Need to continue to pay close attention to central OK tonight / tomorrow morning. RAP and SPC wrf blow up a nice line ahead of the DL as strong upper level forcing moves in, with still 2000J/kg of CAPE in place, and a heck of a lot of low level shear

[KSWx]

Sorry for going slightly off-topic, but why does the SPC's thunderstorm outlook not correspond with NWS forecasts? As an example, the most recent SPC TO has Topeka at a 10% chance to see thunder all day, meanwhile my NWS forecast says 70% chance. Is it because the NWS forecast is for precipitation in general? Thanks in advance, guys.

[Chicago Storm]

Ended up sitting in S. KS, near Kingman, most of the day on Saturday. Called it a day early and am in Wichita for the night.

Depending on how overnight/morning convection evolves, the current plan is to target E. KS/SE. NE/W. MO on Sunday.

[hm8]

[cyclone77]

Sitting in Cameron MO for the night.  Plan on heading down towards the Joplin/Pittsburg KS area in the morning. 

[RandomBlue]

Ended up sitting in S. KS, near Kingman, most of the day on Saturday. Called it a day early and am in Wichita for the night.

Depending on how overnight/morning convection evolves, the current plan is to target E. KS/SE. NE/W. MO on Sunday.

 

What are you seeing that points you towards SE NE vs. NW AR tomorrow?  SE NE is far outside the moderate area.

[janetjanet998]

What are you seeing that points you towards SE NE vs. NW AR tomorrow?  SE NE is far outside the moderate area.

There will likely be two areas of enhanced severe weather the one you mentioned and Southeast NE area...it will be interesting to see if SPC goes with a high risk if they split it in two within a larger moderate risk....or just have an enhanced moderate risk near the low over Southeast NE area which could be rather early

[RCNYILWX]

Leaving from NWS Chicago at 5am and heading to somewhere near KC to assess, hoping initiation ahead of the DL is not too early and we'll have time to position ourselves well. Tonight's guidance looked pretty impressive for our E KS/W MO target area, but a lot will depend on earlier convection as Chicago Storm mentioned.

Sent from my SCH-I535 using Tapatalk

[andyhb]

Dewpoints surging in AR tonight, already 76/65 at Hot Springs.

[Chicago Storm]

What are you seeing that points you towards SE NE vs. NW AR tomorrow? SE NE is far outside the moderate area.

From a chasing stand-point, terrain.

From a potential stand-point, any where from NE/IA down into LA stands the chance at tornadoes, some potentially strong...And a good deal of the 0z guidance supports this scenario.

If overnight/morning convection does not end up being too much of an issue I can see the moderate risk being extended up into far SE. NE and possibly to the IA/MO border. And if they go high risk, which seems quite possible, I could see that extend well into MO...In addition to most of AR. We'll see...A lot hinges on the early convection potential, especially from the MO/AR border on north.

[brettjrob]

What are you seeing that points you towards SE NE vs. NW AR tomorrow?  SE NE is far outside the moderate area.

 

All of W AR is absolutely unchaseable. I mean that in a literal sense. If you go there for an event like tomorrow's, you don't go there to chase. You go to find an overlook within 20 mi. of your preferred target, if you're so lucky, and cross your fingers. It might sound like an exaggeration, but anyone who's chased much and has driven through W AR knows the ugly truth. The visibility and road network are so hellish that you'd most likely have to compromise your safety to score a good view, and even then it might be in vain.

 

Not like W MO is great, either, but at least if you get ahead of a tornado-producing storm it gives you a reasonable chance to watch it cross the road.

 

Believe me, us chasers are desperate. Actually, desperate is far too casual a word, at this point in 2014. But the Ozarks and Ouachitas are really that bad.

[janetjanet998]

..THERE IS A MDT RISK OF SVR TSTMS FROM EXTREME ERN KS  
ERN  
OK...MUCH OF MO...AR...EXTREME NERN TX...WRN TN AND NWRN MS...  
 
...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN PORTIONS OF THE CNTRL  
AND SRN PLAINS THROUGH MUCH OF THE LOWER-MID MS VALLEY AND WRN TN  
VALLEY...  
   
..SUMMARY  
 
NUMEROUS SEVERE STORMS WITH POTENTIAL FOR STRONG TORNADOES...VERY  
LARGE HAIL AND DAMAGING WIND ARE LIKELY ACROSS MUCH OF THE  
MISSISSIPPI RIVER VALLEY...WITH THE GREATEST THREAT FROM THE  
ARK-LA-TEX INTO ARKANSAS...WESTERN TENNESSEE AND WESTERN AND CENTRAL  
MISSOURI AND ERN KS. A SECONDARY THREAT AREA WILL BE FROM EASTERN  
NEBRASKA INTO IOWA...AND STORMS DEVELOPING IN THIS REGION DURING THE  
DAY WILL ALSO LIKELY PRODUCE LARGE HAIL AND SEVERAL TORNADOES.  
   
..SYNOPSIS  
 
VIGOROUS SHORTWAVE TROUGH WILL BE LOCATED ACROSS ERN WRN KS BY 12Z  
SUNDAY AND LIFT NEWD INTO NEB BY LATE SUNDAY AFTERNOON AND EVENING.  
A SECONDARY IMPULSE/JET MAX WILL ADVANCE THROUGH THE BASE OF THE  
UPPER TROUGH AND THROUGH THE SRN PLAINS...REACHING THE LOWER MS  
VALLEY REGION SUNDAY EVENING. AT THE SFC AN AREA OF LOW PRESSURE  
WILL DEEPEN AND LIFT NWD INTO NEB IN ASSOCIATION WITH THE PRIMARY  
SHORTWAVE TROUGH...WHILE A PACIFIC FRONT/DRYLINE SURGES EWD THROUGH  
THE CNTRL AND SRN PLAINS...REACHING THE MID MS VALLEY REGION BY  
EVENING. A WARM FRONT WILL EXTEND EWD FROM THE LOW AND LIFT NWD  
THROUGH NEB AND IA.  
 
...EXTREME ERN PORTIONS OF CNTRL/SRN PLAINS THROUGH LOWER-MID MS AND  
TN VALLEYS...  
 
IT STILL APPEARS THAT MID-LEVEL CONVECTION MAY DEVELOP ABOVE THE CAP  
EARLY IN THE PERIOD ACROSS PORTIONS OF THE SRN PLAINS AND LOWER-MID  
MS VALLEY AREA. HOWEVER...THIS ACTIVITY IS EXPECTED TO SHIFT NEWD  
ALLOWING FOR UPSTREAM DESTABILIZATION. RICH GULF MOISTURE CURRENTLY  
RESIDES ACROSS ERN TX INTO LA AND WILL ADVECT NWD THROUGH THE  
LOWER-MID MS VALLEY WARM SECTOR WITH UPPER 60S DEWPOINTS AS FAR  
NORTH AS ARKANSAS AND MID 60S INTO MO BENEATH PLUME OF STEEP  
MID-LEVEL LAPSE RATES. THIS PROCESS WILL CONTRIBUTE TO AN AXIS OF  
MODERATE INSTABILITY WITH 1500-2000 J/KG MLCAPE EXPECTED BY MID  
AFTERNOON. HOWEVER...WIDESPREAD MULTILAYER CLOUDS SHOULD TEMPER  
BOUNDARY LAYER WARMING AND DESTABILIZATION TO SOME DEGREE.  
 
TWO AREAS OF SURFACE BASED THUNDERSTORM INITIATION APPEAR LIKELY  
INCLUDING ALONG THE DRYLINE/PACIFIC FRONT FROM ERN OK/ERN KS AS WELL  
AS FARTHER SOUTH WITHIN PRE-FRONTAL CONFLUENCE ZONE BY MID  
AFTERNOON...AS THE DIFFLUENT UPPER JET EXIT REGION OVERTAKES THE  
WARM SECTOR. DEEP LAYER WIND PROFILES WILL BECOME VERY FAVORABLE FOR  
SUPERCELLS WITH 0-6 KM SHEAR IN EXCESS OF 50 KT AND 0-1 KM STORM  
RELATIVE HELICITY FROM 200-300 J/KG. INITIAL STORMS ALONG THE  
DRYLINE AS WELL AS PRE-FRONTAL CONFLUENCE ZONE WILL LIKELY BE  
DISCRETE AND POSE A THREAT FOR VERY LARGE HAIL AND TORNADOES...A FEW  
OF WHICH COULD BE STRONG. SOME STORMS MAY EVENTUALLY CONSOLIDATE  
INTO ONE OR MORE MCSS DURING THE EVENING BUT WITH A CONTINUED THREAT  
FOR DAMAGING WIND...TORNADOES AND LARGE HAIL AS ACTIVITY DEVELOPS  
TOWARD THE TN VALLEY. A PORTION OF THE LOWER MS VALLEY MAY NEED TO  
BE INCLUDED IN A HIGH RISK IN LATER UPDATES.  
   
..NEB AND IA  
 
COOL TEMPERATURES ALOFT...STEEP LAPSE RATES AND MODEST LOW LEVEL  
MOISTURE WILL SUPPORT A NARROW AXIS OF MODERATE SURFACE BASED  
INSTABILITY IN VICINITY OF WARM FRONT ACROSS KS INTO IA. FORCING FOR  
ASCENT ASSOCIATED WITH THE EJECTING SHORTWAVE TROUGH WILL INCREASE  
BY LATE MORNING SUPPORTING AN ARC OF STORMS IN VICINITY OF WARM  
FRONT. LARGE...VEERING 0-2 KM HODOGRAPHS AND 50 KT EFFECTIVE SHEAR  
WILL SUPPORT SUPERCELLS WITH TORNADOES AND LARGE HAIL AS ACTIVITY  
DEVELOPS NWD. MODERATE RISK MIGHT BE EXPANDED FARTHER NW TO INCLUDE  
A PORTION OF THIS AREA ON NEXT UPDATE.  
  
 

[andyhb]

...well sadly that doesn't surprise me given who was on the D1 outlook...

[L.B. LaForce]

Eastern AR isnt too bad. I remember busting down there on a high risk day, I think it was 5/1/2010. Tornado probs were like 30% hatched. Anyways, its fairly flat on the eastern side, and definitely chaseable. I'm pretty desperate for a chase this season as well, but these systems have either been trash, or really difficult to chase (terrain, jungles, etc..). That is not to say I haven't done it before, heck, MI has its fair share of trees, but strong or violent tornadoes with a lot of trees is not my cup of tea.

[hm8]

Ended up sitting in S. KS, near Kingman, most of the day on Saturday. Called it a day early and am in Wichita for the night.

Depending on how overnight/morning convection evolves, the current plan is to target E. KS/SE. NE/W. MO on Sunday.

 

HRRR says good call

 

 

 

 

[tornadotony]

The 00z Euro has a distinctly discrete convective signal Monday and overnight into Tuesday morning for nrn/cntl MS and AL.

[PSUBlizzicane2007]

Not upgrading to a high risk is quite weird there considering all of the parameters coming together in AR.  That outlook was weirdly written too... Eastern Western Kansas?  How about West Central Kansas?