April 26th-30th, 2014 Major Tornado Outbreak

[OceanStWx]

It's a battle of the RAP/12-km NAM vs. 4-km NAM/HRRR/EMC WRF as to airmass recovery extent and low-level shear.  Given the performance yesterday, I'll hedge my bets on the latter.

 

I think the HRRR looks very reasonable right now.

[tornadotony]

I think the HRRR looks very reasonable right now.

As do I.  I think SPC's outlook is right on target.

[1900hurricane]

The 12Z JAN sounding really shows how worked over the atmosphere is right now. However, with the low level jet kicking back up, the mid-level vort max rotating on in, and the vast clearing of clouds, we're well on our way to getting the atmosphere recharged for another round of destructive storms. I'm not as high on today as I was yesterday just because I'm not sure the atmosphere can quite recover to the volatility it had yesterday, but the potential is certainly there for another big severe weather/tornado day. Also really like the SPC's placement of the Moderate today.

 

 

[SouthernWx2]

WSFO Jackson just tweeted the following (below) on their Twitter.....

 

 

NWS Jackson MS ‏@NWSJacksonMS  10m

Here is the updated graphic for today's expected severe weather. Note: SE MS now in a high risk. pic.twitter.com/7IDIoeOT3v

 

[CoastalWx]

The LLJ last night will probably be stronger than what we see this evening, but I did notice winds at 925mb seem like they will be a bit more SW as compared to last night. As long as we recover and I think we will..it could be an interesting late aftn and evening once again.

[OceanStWx]

WSFO Jackson just tweeted the following (below) on their Twitter.....

 

 

NWS Jackson MS ‏@NWSJacksonMS  10m

Here is the updated graphic for today's expected severe weather. Note: SE MS now in a high risk. pic.twitter.com/7IDIoeOT3v

 

I don't think they mean high as in a SPC outlook, that's a local product used to convey their own thoughts (see the extreme category).

[Solak]

‏Backtracking to a couple days ago...

 

@EntergyArk 7m

Officials say 3000+ homes in Vilonia/Mayflower are damaged, uninhabitable. #arwx pic.twitter.com/zfwi54u09L

[Wmsptwx]

Set up not quite as primed as yesterday, but like many have said plenty if severe will likely occur.

[mappy]

WSFO Jackson just tweeted the following (below) on their Twitter.....

 

 

NWS Jackson MS ‏@NWSJacksonMS  10m

Here is the updated graphic for today's expected severe weather. Note: SE MS now in a high risk. pic.twitter.com/7IDIoeOT3v

 

I think that is their own WFO categories, not SPC's categories.

 

edit: ninja'd

[hm8]

[Thrasher Fan]

SPC AC 291630

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1130 AM CDT TUE APR 29 2014

VALID 291630Z - 301200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR SRN

AND ERN MS INTO W CENTRAL/SW AL...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS VALLEY TO THE

GREAT LAKES AND NC/VA...

...SUMMARY...

SCATTERED TO NUMEROUS SEVERE THUNDERSTORMS WILL AFFECT PORTIONS OF

THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS INTO CENTRAL AND EASTERN

GULF STATES THIS AFTERNOON INTO TONIGHT. SEVERAL TORNADOES...A FEW

OF WHICH COULD BE STRONG...VERY LARGE HAIL AND STRAIGHT LINE

DAMAGING WINDS APPEAR LIKELY.

...MS/AL AND VICINITY THROUGH TONIGHT...

A 90-120 KT MID-UPPER JET STREAK WILL TRANSLATE QUICKLY NEWD FROM TX

TO THE OH VALLEY TODAY...WITH ASCENT ACCOMPANYING THE JET STREAK

MANIFESTED AS THE MID CLOUD BAND FROM TXK-JBR. IN RESPONSE TO THIS

JET STREAK...A WEAK SURFACE WAVE IS FORECAST TO DEVELOP NEWD FROM LA

TO THE TN VALLEY...BEGINNING AT THE INTERSECTION OF THE SYNOPTIC

COLD FRONT A REMNANT OUTFLOW BOUNDARY IN CENTRAL LA. IN THE WAKE OF

A LARGE OVERNIGHT MCS...RAPID RECOVERY IS ENSUING FROM LA TO SRN MS

AS SURFACE HEATING OCCURS AND THE MARITIME TROPICAL AIR SPREADS

NEWD. THE PLUME OF STEEPER MIDLEVEL LAPSE RATES HAS BEEN CONFINED

TO THE NW GULF COAST...WITH WEAKER LAPSE RATES WHERE WIDESPREAD

CONVECTIVE OVERTURNING OCCURRED OVERNIGHT.

THE LOWER 70S BOUNDARY LAYER DEWPOINTS AND SURFACE TEMPERATURES

WARMING INTO THE LOW 80S WILL RESULT IN MLCAPE OF 2500-3500 J/KG

ACROSS LA BY MIDDAY...WHILE LESSER BUOYANCY WILL DEVELOP NEWD INTO

AL. STRONG DEEP-LAYER VERTICAL SHEAR WILL SUPPORT SUPERCELL

DEVELOPMENT IN THE ZONE OF RAPID DESTABILIZATION...AND A COMBINATION

OF DISCRETE CELLS AND CLUSTERS WILL SUBSEQUENTLY SPREAD NEWD ACROSS

MS/AL DURING THE AFTERNOON. LARGE HAIL /SOME SIGNIFICANT/ AND

DAMAGING WINDS CAN BE EXPECTED WITH THESE STORMS...WITH THE

POTENTIAL FOR ANOTHER MCS TO EVOLVE BY THIS EVENING ACROSS CENTRAL

AL. EFFECTIVE BULK SHEAR AOA 70 KT AND EFFECTIVE SRH OF 150-200

M2/S2 IN A MOISTENING ENVIRONMENT WILL SUPPORT THE RISK FOR

TORNADOES...AND POSSIBLY A COUPLE STRONG TORNADOES WITH THE MORE

DISCRETE STORMS LATER THIS AFTERNOON.

...NC THIS AFTERNOON...

SURFACE HEATING ALONG A WARM FRONT WILL EVENTUALLY RESULT IN

SUFFICIENT DESTABILIZATION FOR THUNDERSTORM DEVELOPMENT THIS

AFTERNOON. THOUGH LAPSE RATES ARE NOT PARTICULARLY STEEP...MODERATE

BUOYANCY IS STILL EXPECTED WITH THE INCREASING LOW-LEVEL MOISTURE.

ALSO...VERTICAL SHEAR PROFILES ALONG THE FRONT WILL BE FAVORABLE FOR

SUPERCELLS...WITH AN ATTENDANT RISK FOR A COUPLE TORNADOES IN

ADDITION TO LARGE HAIL AND DAMAGING WINDS.

...OH VALLEY/GREAT LAKES THIS AFTERNOON...

SURFACE HEATING IS UNDERWAY WITHIN THE WARM SECTOR...BUT THE SURFACE

FOCUS FOR STORM INITIATION IS UNCLEAR GIVEN THE SUBTLE NATURE OF THE

SYNOPTIC FRONT. STILL..WITH THE EXIT REGION OF THE UPPER JET

APPROACHING...SCATTERED LOW-TOPPED STORMS SHOULD FORM AND SPREAD

NWD/NEWD...WITH AN ACCOMPANYING ISOLATED SEVERE RISK.

..THOMPSON/SMITH.. 04/29/2014

[David Reimer]

I'll be setting up on Highway 49 southeast of Jackson probably from Magee to Collins for storms to cross between 20:30Z and 22:00Z. 

[Quincy]

I'll be setting up on Highway 49 southeast of Jackson probably from Magee to Collins for storms to cross between 20:30Z and 22:00Z. 

Looking like a good spot. In Brandon now and gradually heading a bit east early this afternoon. We probably won't have to go far at all.

 

I would like to move east into Alabama later on, setting up for another day of storms across Georgia and the Carolinas tomorrow.

[David Reimer]

Looking like a good spot. In Brandon now and gradually heading a bit east early this afternoon. We probably won't have to go far at all.

 

I would like to move east into Alabama later on, setting up for another day of storms across Georgia and the Carolinas tomorrow.

 

Sounds good! I agree Alabama is probably going to get slammed later tonight but I refuse to head into Alabama. I'll spend the mid-afternoon intercepting whatever storms come across 49 and then start heading back to Texas. Good luck today and stay safe!

[Hoosier]

hello

 

...

BULLETIN - EAS ACTIVATION REQUESTED  TORNADO WARNING  NATIONAL WEATHER SERVICE QUAD CITIES IA IL  1144 AM CDT TUE APR 29 2014    THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A    * TORNADO WARNING FOR...    CENTRAL STEPHENSON COUNTY IN NORTHWEST ILLINOIS...    * UNTIL 1215 PM CDT    * AT 1138 AM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A    TORNADO WAS LOCATED NEAR FORRESTON...AND MOVING NORTH AT 30 MPH.    

[Thrasher Fan]

At last check cloud burn off continues rapidly from west to east across MS, AL and west GA.

[OceanStWx]

 

hello

 

...

BULLETIN - EAS ACTIVATION REQUESTED  TORNADO WARNING  NATIONAL WEATHER SERVICE QUAD CITIES IA IL  1144 AM CDT TUE APR 29 2014    THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A    * TORNADO WARNING FOR...    CENTRAL STEPHENSON COUNTY IN NORTHWEST ILLINOIS...    * UNTIL 1215 PM CDT    * AT 1138 AM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A    TORNADO WAS LOCATED NEAR FORRESTON...AND MOVING NORTH AT 30 MPH.    

 

The "cold air" funnel type tornado. Brief touchdown reported, though there is a decent couplet that showed up south of FEP

[yoda]

Updated Public Severe Weather Outlook from SPC as of 12:52 PM/11:52 AM:

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

 

 

PUBLIC SEVERE WEATHER OUTLOOK    NWS STORM PREDICTION CENTER NORMAN OK  1152 AM CDT TUE APR 29 2014    ...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE GULF COAST STATES  THIS AFTERNOON AND TONIGHT...    * LOCATIONS...    EASTERN AND SOUTHERN MISSISSIPPI    WESTERN ALABAMA    EXTREME EASTERN LOUISIANA    * HAZARDS...    SEVERAL TORNADOES, A FEW INTENSE    SCATTERED LARGE HAIL, SOME BASEBALL SIZE    SCATTERED DAMAGING WINDS    * SUMMARY...    SCATTERED TO NUMEROUS SEVERE THUNDERSTORMS WILL AFFECT PORTIONS    OF THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS INTO CENTRAL AND    EASTERN GULF STATES THIS AFTERNOON INTO TONIGHT. SEVERAL    TORNADOES, A FEW OF WHICH COULD BE STRONG, VERY LARGE HAIL AND    STRAIGHT LINE DAMAGING WINDS APPEAR LIKELY.    

[BuffaloWeather]

 

hello

 

...

BULLETIN - EAS ACTIVATION REQUESTED  TORNADO WARNING  NATIONAL WEATHER SERVICE QUAD CITIES IA IL  1144 AM CDT TUE APR 29 2014    THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A    * TORNADO WARNING FOR...    CENTRAL STEPHENSON COUNTY IN NORTHWEST ILLINOIS...    * UNTIL 1215 PM CDT    * AT 1138 AM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A    TORNADO WAS LOCATED NEAR FORRESTON...AND MOVING NORTH AT 30 MPH.    

1620   SHANNON CARROLL IL 4215 8974 BRIEF TOUCH DOWN. NO DAMAGES REPORTED. (DVN)

[geddyweather]

Definetly priming up again, clearing out quickly over MS and AL. Not seeing any good initiation quite yet, but there is some stuff popping up over northern LA currently. Birmingham area might have to be on guard again if these storms continue taking the same northeast track they did last night.

 

Meanwhile up here in NW OH, clear skies and very juicy outside. SBCape 1500-2000 j/kg, MLCape 1000 j/kg, and 50-60kt of shear at the 6km height. Thinking mostly surface-based stuff here

 

Thoughts?

[geddyweather]

Lookie there....

 

 AREAS AFFECTED...PORTIONS OF NERN AND SERN LA / MUCH OF SRN AND
   CNTRL MS

   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

   VALID 291702Z - 291830Z

   PROBABILITY OF WATCH ISSUANCE...95 PERCENT

   SUMMARY...THUNDERSTORM INITIATION IS FORECAST WITHIN THE NEXT HOUR
   OR TWO.  RAPID SEVERE STORM DEVELOPMENT WILL OCCUR THIS AFTERNOON
   AND A TORNADIC SUPERCELL THREAT WILL LIKELY ENSUE AS STORMS MATURE.

   DISCUSSION...RECENT SURFACE MESOANALYSIS PLACES A COLD FRONT OVER
   PARTS OF THE LOWER MS RIVER VALLEY EXTENDING SWWD INTO THE UPPER TX
   COASTAL PLAIN.  AN ARCING OUTFLOW BOUNDARY FROM A PRIOR MCS
   --CURRENTLY OVER THE NERN GULF OF MEXICO-- IS DRAPED FROM NEAR THE
   MOUTH OF THE MS RIVER INTO FAR SWRN MS.  THE AIRMASS TO THE S AND W
   OF THE OUTFLOW BOUNDARY IS BECOMING QUITE UNSTABLE WITH AN AGITATED
   CU FIELD DEVELOPING OVER MUCH OF LA AND STRONG HEATING OCCURRING
   OVER MUCH OF MS.  AS LOW-LEVEL MOISTURE ADVANCES NWD ON THE BACKSIDE
   OF THE OUTFLOW BOUNDARY...MODERATE TO STRONG /1500-2500 J PER KG
   MLCAPE/ DESTABILIZATION IS EXPECTED. 

   AS ASCENT PROVIDED BY A 130 KT JET STREAK AND BOUNDARY LAYER
   HEATING/MOISTENING OCCUR...THUNDERSTORMS ARE FORECAST TO DEVELOP
   FIRST NEAR THE MS RIVER AND SPREAD EWD THIS AFTERNOON THROUGH MS AND
   EVENTUALLY INTO AL.  STRONG DEEP-LAYER FLOW FIELDS WILL STRONGLY
   FAVOR SUPERCELLULAR STORM MODES AND A FORECAST STRENGTHENING IN H85
   FLOW /30-40 KT/ THIS AFTERNOON INTO THIS EVENING WILL BOOST
   LOW-LEVEL SHEAR AND CONCURRENTLY SUPPORT AN INCREASE IN TORNADO
   POTENTIAL.  GIVEN THIS SCENARIO...LONGER-LIVED SUPERCELLS CAPABLE OF
   TORNADOES /SOME POSSIBLY STRONG/ AND A LARGE TO VERY LARGE HAIL
   THREAT IS PROBABLE.

   ..SMITH/THOMPSON.. 04/29/2014
 

[Hoosier]

The "cold air" funnel type tornado. Brief touchdown reported, though there is a decent couplet that showed up south of FEP

 

 

Kinda neat as temps are only in the low 50s in that area.

[wxmeddler]

Hysplit for 400, 700 and near Sfc. for Meridian at 00z.

 

[valkhorn]

Hysplit for 400, 700 and near Sfc. for Meridian at 00z (MEI)20140428_Hysplit_MEI.PNG

 

Edit: Oops, that 700 is actually 500. I messed up, doing another one.

 

Does this mean there's a bullseye around Meridian now?

[mfgmfg]

Does this mean there's a bullseye around Meridian now?

No, I think that's just the point where he initiated the model to work backwards from. Searching the forum for posts on Hysplit seems to say that this method is a way to track where the parcels came from and make some assumptions about their temperature and behavior since then to figure out what temps/moisture you will have at that point? Please correct me if I am wrong.

[wxmeddler]

No, I think that's just the point where he initiated the model to work backwards from. Searching the forum for posts on Hysplit seems to say that this method is a way to track where the parcels came from and make some assumptions about their temperature and behavior since then to figure out what temps/moisture you will have at that point? Please correct me if I am wrong.

 

Correct.

[OceanStWx]

No, I think that's just the point where he initiated the model to work backwards from. Searching the forum for posts on Hysplit seems to say that this method is a way to track where the parcels came from and make some assumptions about their temperature and behavior since then to figure out what temps/moisture you will have at that point? Please correct me if I am wrong.

 

It essentially can backtrack to where a model parcel originated from. So what we can assume is that the 700-500 mb lapse rates will be originating from a point over west TX, while the low level moisture is coming in from straight off the GoM. You could then match observations in these areas to get an idea of expected conditions this afternoon for near MEI.

 

Hysplit can also work forward to forecast where parcels will travel (i.e. in the event of a toxic release).

[Chinook]

Just for kicks. Possible supercell over the Gulf of Mexico, 70 nautical miles from Mobile radar (1644z, this is about 45 minutes ago) rotational couplet tracked through 29.50N 88.38W, to 29.54N, 88.21W.

 

[yoda]

URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 116

NWS STORM PREDICTION CENTER NORMAN OK

1245 PM CDT TUE APR 29 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF

EXTREME SOUTHWEST ALABAMA

PARTS OF NORTHEAST AND SOUTHEAST LOUISIANA

CENTRAL AND SOUTHERN MISSISSIPPI

* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1245 PM UNTIL

900 PM CDT.

* PRIMARY THREATS INCLUDE...

SEVERAL TORNADOES LIKELY WITH A COUPLE INTENSE TORNADOES

POSSIBLE

WIDESPREAD LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2.5

INCHES IN DIAMETER LIKELY

SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 105 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTHEAST OF

MERIDIAN MISSISSIPPI TO 25 MILES WEST OF NATCHEZ MISSISSIPPI.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU6).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

DISCUSSION...THUNDERSTORMS WILL INTENSIFY BOTH ALONG A RETREATING

OUTFLOW BOUNDARY IN SE MS/SW AL...AND IN THE EXPANDING WARM SECTOR

FROM NE LA INTO MS THE NEXT FEW HOURS. DESTABILIZATION AND STRONG

DEEP-LAYER VERTICAL SHEAR WILL FAVOR SUPERCELLS CAPABLE OF PRODUCING

TORNADOES...LARGE HAIL...AND DAMAGING WINDS. A COUPLE STRONG

TORNADOES WILL BE POSSIBLE THIS AFTERNOON WITH THE MOST INTENSE

SUPERCELLS...AS WELL AS ISOLATED VERY LARGE HAIL. BY ABOUT MID

AFTERNOON...THE SEVERE THREAT WILL SPREAD EWD INTO W CENTRAL AL.

[yoda]