Tornado Outbreak April 29-May 2, HIGH RISK AR, TN, MS

[srainhoutx]

Anyone notice Shreveport radar.

[CrazyC83]

Revisiting the already-extended watch.

MESOSCALE DISCUSSION 0448
NWS STORM PREDICTION CENTER NORMAN OK
0504 PM CDT SAT MAY 01 2010

AREAS AFFECTED...NRN MS/AL AND SRN TN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 012204Z - 012300Z

ROTATING STORMS CONTINUE TO DEVELOP OVER PORTIONS OF NRN MS/AL AND
SRN TN. ALTHOUGH A LOCAL TIME EXTENSION HAS BEEN ISSUED FOR
WW124...THE AREA WILL NEED TO BE MONITORED FOR A POSSIBLE NEW WW.

UPPER WAVES NOTED ON WV IMAGERY IN CNTRL MS AND OVER MUCH OF TN THAT
INFLUENCED CURRENT CONVECTION ARE QUICKLY MOVING NEWD...WITH
SUBSIDENCE IN THEIR WAKE. THIS MAY LIMIT MORE ROBUST CONVECTION OVER
THE NEXT FEW HOURS. HOWEVER...HIGHER THETA-E AIR TO THE SOUTH WILL
CONTINUE TO FEED INTO CURRENT CONVECTION...WITH AREA VAD WIND
PROFILE DATA INDICATING AMPLE LOW LEVEL HELICITY /0-3 KM 400-550
M2/S2 / TO SUPPORT ROTATING STORMS CAPABLE OF DMGG WINDS AND ISOLD
TORNADOES. AS UPPER RIDGING QUICKLY PROGRESSES EWD...CONVECTION MAY
BECOME MORE INTENSE AS THE NEXT UPPER DISTURBANCE APPROACHES...AND
AS THE LOW LEVEL JET BEGINS TO INCREASE THIS EVENING. CHARACTER OF
CONVECTION WILL CONTINUE TO BE MONITORED...WITH A WW BECOMING LIKELY
SHOULD MORE ORGANIZATION BE NOTED.

..HURLBUT.. 05/01/2010


ATTN...WFO...MRX...FFC...OHX...BMX...HUN...MEG...JAN...

LAT...LON 33248795 32718910 32959007 33919057 34729041 35538969
35508842 35488789 35678547 35558459 35028466 34368613
33548718 33248795

[CrazyC83]

Anyone notice Shreveport radar.

I'm guessing within 90 minutes there will be so much on the plate we can hardly keep track.

[wx247]

The longer it takes to get going, the closer it is to dark. Nighttime tornadoes are so very, very dangerous.

[brunota2003]

I already cant keep track of it...I gave up on trying to get the images to load...by the time I got one set, they were already 10 or 15+ minutes behind! Anyone care to post radar images here (especially of any cells that have confirmed tornadoes) feel free to.

[KWT]

Anyone notice Shreveport radar.

Ye just had a look at it, there is a lot of cells there ready to up from the looks of things and explode...

I'm going to have a nightmare keeping up with all the warnings I think past 00z....

[CrazyC83]

Anyone notice Shreveport radar.

Ye just had a look at it, there is a lot of cells there ready to up from the looks of things and explode...

I'm going to have a nightmare keeping up with all the warnings I think past 00z....

The staging for posting warnings here should be:

1) The first few cells should have any Tornado Warnings posted. Only the first cell should have a Severe Thunderstorm Warning posted.

2) Once activity gets going, then we should stick to surface-confirmed warnings, those headed for large communities and those with stronger wording.

3) If it gets too hard to handle, only post very strongly-worded ones (like Tornado Emergencies) and those headed to places of high interest.

[Mindi]

Storms firing SE of Hot Springs...will they continue to gain strength?

[CrazyC83]

Storms firing SE of Hot Springs...will they continue to gain strength?

So far it seems they are, but they can't seem to cross severe limits yet. The cap is still trying to fight, but how long does it have left?

[KWT]

I'll leave most of that to you if thats ok Crazy, simply because there is going to be many radar based tornado warnings that I'll put in the other thread that I run and I probably won't be able to do both, Bunkertor did a good job helping me out on that front yesterday night.

As for the cap, well the WRF 0z run this morning didn't really break out anything of note till about 01z, which maybe a little later then what happens but so far its playing out well...as someone else said, the longer it holds the bigger the risk of big night time tornadoes.

[CrazyC83]

I'll leave most of that to you if thats ok Crazy, simply because there is going to be many radar based tornado warnings that I'll put in the other thread that I run and I probably won't be able to do both, Bunkertor did a good job helping me out on that front yesterday night.

I usually don't bother at all on radar-based Tornado Warnings during outbreaks, unless they are headed for a large population center or for one of our own active members.

[srainhoutx]

Welcome Mindi! Hope you learned a thing or two chasing.

[RL3AO]

The NWS servers just can't handle the traffic with the level 3 data. They upgraded the resolution and hopefully they upgrade the servers.

[Mindi]

Thanks srainhoutx! I hope I learned a bit...lol! Looks like the cap is breaking in Arkansas, storms are continuing to fire.

[KWT]

Yeah I can't see the cap lasting much longer to be honest...

RL3AO, I was wondering why they wasn't working earlier on!

[RL3AO]

RL3AO, I was wondering why they wasn't working earlier on!

Same think happened last week. Probably have to buy Allison house feed, even if its just for the busy part of the season. I'm just using my GR2 trial.

[CrazyC83]

The cells in S Arkansas already seem to be rotating, even though wind and hail are not at severe limits yet.

[CrazyC83]

Only a small area in SE Tennessee was put into the new watch with borderline probs (30/10). They might be planning a large PDS watch from central LA to middle TN for mid-evening.

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 126
NWS STORM PREDICTION CENTER NORMAN OK
635 PM EDT SAT MAY 1 2010

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTHERN MIDDLE AND SOUTHEAST TENNESSEE

EFFECTIVE THIS SATURDAY EVENING FROM 635 PM UNTIL 1100 PM EDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 90 MILES WEST SOUTHWEST OF
CROSSVILLE TENNESSEE TO 65 MILES EAST SOUTHEAST OF CROSSVILLE
TENNESSEE. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 124. WATCH NUMBER 124 WILL NOT BE IN EFFECT AFTER
635 PM EDT. CONTINUE...WW 125...

DISCUSSION...REMNANT MCS WILL CONTINUE TO MOVE EWD ACROSS SRN MIDDLE
AND SERN TN THE NEXT FEW HOURS...FED BY A MOISTURE INFLUX FROM THE S
ATOP AND SLOW-MOVING FRONT NEAR THE SRN TN BORDER. THOUGH THE
CONVECTION IN THE NRN PART OF THE WATCH MAY REMAIN SLIGHTLY
ELEVATED...THE STORMS ALONG THE IMMEDIATE FRONT/OUTFLOW ACROSS SRN
TN WILL BE ROOTED AT OR VERY NEAR THE SURFACE. GIVEN THE MOISTURE
INFLUX FROM THE S AND STRENGTH OF VERTICAL SHEAR IN LOCAL VWP/S...A
FEW EMBEDDED ROTATING STORMS AND AN ATTENDANT THREAT FOR A TORNADO
OR TWO WILL PERSIST FOR A FEW MORE HOURS. DAMAGING WINDS AND LARGE
HAIL SHOULD BE THE MORE COMMON THREATS IN THE WATCH AREA THIS
EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 26025.


...THOMPSON

[Mindi]

Storms are exploding in Arkansas, cap is being blown away!

[CrazyC83]

MESOSCALE DISCUSSION 0449
NWS STORM PREDICTION CENTER NORMAN OK
0543 PM CDT SAT MAY 01 2010

AREAS AFFECTED...PARTS OF CENTRAL AND SRN AR/NRN LA/NERN TX

CONCERNING...TORNADO WATCH 125...

VALID 012243Z - 012345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 125 CONTINUES.

CONVECTION/UPDRAFTS ARE BECOMING MORE PERSISTENT FROM WEST CENTRAL
AR /HOT SPRING TO GARLAND COUNTIES AR/ ENEWD TO CROSS COUNTY AR IN
THE VICINITY OF A SURFACE BOUNDARY EXTENDING WSW-ENE THROUGH THIS
REGION. REGIONAL RADARS/LIGHTNING DATA SHOWED STORMS DEVELOPING IN
THIS CORRIDOR. OBJECTIVE ANALYSES INDICATED THIS 40 MILE WIDE ZONE
EXTENDING FROM 30 WSW HOT TO 25 NW MEM IS A FAVORABLE ZONE FOR
SUSTAINED ROTATING UPDRAFTS. THIS WILL BE ESPECIALLY SUBSTANTIAL
WITH ANY STORM THAT TRACKS ENEWD ALONG THE BOUNDARY WHERE ENELY
WINDS ON THE N SIDE OF THE BOUNDARY ARE ENHANCING LOW LEVEL SHEAR
/LIT WSR-88D VWP SFC-1 KM SHEAR 30 KT/. AN ENEWD STORM MOTION ALONG
THE BOUNDARY WILL ALSO PROVIDE A LONGER RESIDENCE TIME FOR THE
UPDRAFTS/SUPERCELLS TO INGEST STREAM-WISE VORTICITY...INCREASING THE
TORNADO POTENTIAL.

AT 22Z...WATER VAPOR IMAGERY SHOWED SHORTWAVE RIDGING MOVING NEWD
ACROSS AR WHICH MAY HAVE BEEN INHIBITING MORE ROBUST UPDRAFT
DEVELOPMENT THUS FAR THIS AFTERNOON. HOWEVER...THE RICH MOIST
BOUNDARY LAYER /SURFACE DEWPOINTS IN THE LOWER 70S/ IS LIKELY
BEGINNING TO SENSE THE EFFECTS OF LARGE SCALE ASCENT/STEEPER MID
LEVEL LAPSE RATES SPREADING NEWD WITH THE APPROACH OF AN UPSTREAM
TROUGH...NOW LOCATED ALONG THE TX RIO GRANDE VALLEY. STRENGTHENING
SWLY MID LEVEL WINDS AND SSWLY LLJ WITH THE APPROACH OF THE RIO
GRANDE TROUGH WILL FURTHER ENHANCE THE LIKELIHOOD FOR STRONG
TORNADIC SUPERCELLS THROUGH THE EVENING.

..PETERS.. 05/01/2010


ATTN...WFO...MEG...JAN...LZK...SHV...

LAT...LON 34529348 34839333 35099266 35459151 35788992 34869048
33749129 32899173 32259238 32349370 32569482 33699418
34299365 34529348