Archive Severe threat April 26-27, 2011

[TW Archive]

mwbwhorton
Posted 26 April 2011 - 03:43 PM

Storms really firing now from dallas ft worth to waco and austin.....

 

[TW Archive]

bingcrosbyb
Posted 26 April 2011 - 03:54 PM

Off the charts high Craven-Brooks number.

 

[TW Archive]

NorthGaWeather
Posted 26 April 2011 - 04:00 PM

Mr. Nelson's FFC AFD...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
444 PM EDT TUE APR 26 2011

...WIDESPREAD SEVERE THUNDERSTORMS AND TORNADOES EXPECTED MAINLY WEDNESDAY EVENING... SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/

PRIMARY CONCERN IS INTENSITY AND TIMING FOR SEVERE CONVECTION. INGREDIENTS FOR SEVERE STORMS ON WEDNESDAY COULD BE DISCUSSED IN GREAT DETAIL ...BUT SUFFICE TO SAY THAT THERE ARE ALL THERE AND IN ABUNDANCE.

IN THE NEAR TERM...CONVECTION HAS FAILED TO MATERIALIZE IN SPITE OF TEMPS IN THE LOW 80S. A LACK OF A SFC FOCUSING MECHANISM SUCH AS A FRONT OR OTHER BOUNDARY MAY BE TO BLAME ALTHOUGH SFC CONVERGENCE WAS INCREASING OVER NE ALABAMA AND FAR NW GA. NEAR TERM POPS MAY BE TOO HIGH IF STORMS FAIL TO DEVELOP...FOR NOW HAVE FAITH THAT A FEW STORMS WILL FIRE. IF IT HASNT BY 7PM...PROBABLY NEED TO LOWER POPS. SIMILARLY...STORMS OVER THE MID SOUTH ALSO SLOW TO DEVELOP. MODELS SHOW STORMS SHOULD DEVELOP INTO A SQUALL LINE /QLCS/ AND PUSH EAST INTO AL OVERNIGHT BEFORE WEAKENING. HAVE GONE AT OR BELOW GUIDANCE FOR POPS LATE TONIGHT AND WED MORNING...BUT THESE MAY NEED TO BE TWEAKED FURTHER DOWN BASED ON TRENDS EVOLUTION OF QLCS TO THE WEST.

PRIMARY CONCERN IS LATE WED AFTERNOON AND ESP WED NIGHT. MOST LIKELY TIME WILL BE BETWEEN 6PM AND MIDNIGHT. INSTABILITY WILL REMAIN VERY HIGH WITH MLCAPE 1500-3000 J/KG JUST TO THE WEST. STRONG VERTICAL WIND SHEAR IS PROGGED TO BE IN PLACE AS WELL... 0-1KM BULK SHEAR IS 40-50KTS PEAKING AROUND 03Z OVER NORTH GA. AS DISCUSSED EARLIER...COMPOSITE INDICATES SUCH AS SIG TOR PARAMETER OR EHI ARE AT EXTREME LEVELS...NEAR THE HIGHEST I HAVE PERSONALLY SEEN ON MODEL PROGS. IT IS POSSIBLE THE MODELS ARE OVERDOING THE INSTABILITY AND THUS THE STP...HOWEVER IT SEEMS TO BE IN LINE SO FAR TODAY.

 

[TW Archive]

mbrewer
Posted 26 April 2011 - 04:07 PM

18Z NAM run has the surface winds backing a little more toward the S and SE in response to the low. That is one large area of high EHI values for tomorrow

 

[TW Archive]

mwbwhorton
Posted 26 April 2011 - 04:08 PM

massive energy coming out of the texas panhandle hense the severe t storm watch up that way,dr forbes just said when the panhandle energy hits the moister flow its going to explode....
Edited by mwbwhorton, 26 April 2011 - 04:09 PM.

 

[TW Archive]

mwbwhorton
Posted 26 April 2011 - 04:11 PM

Also dfw storm is a well defined supercell according to forbes now....

 

[TW Archive]

sutton82
Posted 26 April 2011 - 04:12 PM

I wouldn't be surprised if that storm se of dallas was producing right now.

 

[TW Archive]

mhking
Posted 26 April 2011 - 04:15 PM

Snowowl, on 26 April 2011 - 01:31 PM, said:

Huffines posted this todaylease remember, even in 'outbreaks', tornadoes are still random and fairly rare. Remain aware, avoid panic-spreaders.

I don't talk much on the board here (I prefer to let more experienced voices speak -- I soak it all in, myself), but this guy sounds outright irresponsible and potentially dangerous. He could honestly be putting people's lives at risk with talk like that.

That being said, hi everyone, and thanks for putting up with lurkers like me here.

M

 

[TW Archive]

steveklein
Posted 26 April 2011 - 04:17 PM

re: huffines
well, he is right in a way... in even the most severe outbreaks, what % of land actually suffers tornado damage? 1%?

 

[TW Archive]

ALhurricane
Posted 26 April 2011 - 04:20 PM

steveklein, on 26 April 2011 - 04:17 PM, said:

re: huffines
well, he is right in a way... in even the most severe outbreaks, what % of land actually suffers tornado damage? 1%?

Well if I follow his logic, then we should all just cancel our homeowner's insurance...

 

[TW Archive]

steveklein
Posted 26 April 2011 - 04:21 PM

tornado warnings now out for arkansas storms. FOX16 streaming live online http://www.fox16.com/content/live/default.aspx

 

[TW Archive]

bhwhiz
Posted 26 April 2011 - 04:23 PM

BMX:

AND NOW FOR THE MAIN EVENT. A SIMILAR SETUP WILL EXIST FROM WHAT WE
SAW BACK ON APRIL 15TH...AS SEVERAL WAVES OF ENERGY WILL BE MOVING
INTO OUR AREA FROM THE ARKLAMISS WITH A 65KT 850MB JET DEVELOPING.
WE WILL HAVE TO CLOSELY WATCH THE DEVELOPMENT OF THE LINE OF
THUNDERSTORMS...AS THIS WILL HAVE A LARGE IMPACT ON THE DEVELOPMENT
OF SEVERE THUNDERSTORMS LATE IN THE DAY. IF THE LINE HOLDS
TOGETHER...SEVERE PARAMETERS WILL BE GREATLY REDUCED ONCE THE LINE
PASSES. OUR CONFIDENCE IN THAT SOLUTION IS VERY LOW HOWEVER...AND WE
ARE EXPECTING THE LINE TO BE GREATLY WEAKENED BY THE TIME IT REACHES
OUR AREA...AND WILL ALLOW FOR A RAPID DESTABILIZATION OF THE
ATMOSPHERE AFTER MIDDAY TOMORROW. AFTER TALKING WITH SPC...THE
UNCERTAINTY IN THE STRENGTH AND LOCATION OF ONGOING CONVECTION
TOMORROW MORNING IS THE ONLY FACTOR THAT IS PREVENTING THE ISSUANCE
OF A HIGH RISK OF SEVERE STORMS AT THIS TIME.
LOOKING AT THE LATEST FORECAST SOUNDINGS...NOT MUCH HAS CHANGED IN
RELATION TO PARAMETERS THAT WE HAVE BEEN ADVERTISING OVER THE PAST
FEW DAYS. ONE WORD COMES TO MIND AFTER LOOKING AT SEVERAL SOUNDINGS.
DANGEROUS. A WEAK CAP SHOULD BE IN PLACE THROUGH THE EARLY MORNING
HOURS...THEN RAPIDLY ERODE DURING THE LATE MORNING AND EARLY
AFTERNOON. AMPLE TURNING OF THE WINDS WITH HEIGHT...DRY AIR
ALOFT...AND STEEP LAPSE RATES WILL BE PREVALENT ACROSS ALL OF
CENTRAL ALABAMA TOMORROW AFTERNOON. THE MOST UNSTABLE AREAS WILL BE
GENERALLY ALONG AND NORTH OF INTERSTATE 20...BUT I MUST STRESS THAT
ALL OF CENTRAL ALABAMA WILL BE UNDER THE GUN.

MOST SEVERE WEATHER PARAMETERS ARE OFF THE CHARTS TOMORROW
AFTERNOON. THE CRAVEN/BROOKS SIGNIFICANT SEVERE PARAMETER...WHICH
INCORPORATES 100MB MLCAPE AS WELL AS THE 0-6KM SHEAR...IS BETWEEN
60000 TO 80000. USUALLY YOU WILL SEE SIGNIFICANT SEVERE EVENTS OCCUR
WHEN THE VALUE IS ABOVE 20000. THAT ON TOP OF ALMOST 3000J/KG OF
SBCAPE IS A VERY DANGEROUS MIXTURE. 0-6KM SHEAR OF 60-80KTS...WITH
VECTORS SUGGESTING SUPERCELL DEVELOPMENT REMAINS IN PLACE AHEAD OF
THE FRONT. ALONG THE FRONT...SHEAR VECTORS CONTINUE TO INDICATE THE
DEVELOPMENT OF SUPERCELLS UNTIL LATE IN THE EVENING AS THE FRONT
APPROACHES EASTERN ALABAMA. THE SHEAR VECTORS THEN BECOME SLIGHTLY
MORE PARALLEL TO THE FLOW...INDICATING A MORE LINEAR
DEVELOPMENT...BUT TORNADOES ALONG THE LINE WILL CONTINUE TO BE
POSSIBLE. ONCE AGAIN...THE DEVELOPMENT OF STORMS TONIGHT WILL HAVE A
MODEST IMPACT ON THE MESOSCALE TOMORROW...AND HOW THE EVENT PLAYS
ITSELF OUT. I MUST ALSO STRESS THAT NOW IS THE TIME TO REVIEW YOUR
SEVERE WEATHER PLAN TO PROTECT YOUR LIFE AND PROPERTY...TOMORROW
WILL BE TOO LATE!

 

[TW Archive]

steveklein
Posted 26 April 2011 - 04:24 PM

ALhurricane, on 26 April 2011 - 04:20 PM, said:

Well if I follow his logic, then we should all just cancel our homeowner's insurance...

well, actually... for every dollar the average person puts into insurance, they will get less than a dollar back over the course of their lifetime. you only do it as an insurance to a catastrophic loss... over an infinite sample size, insurance is a bad investment. unfortunately, because of the randomness of catastrophe, we can't take that risk.

 

[TW Archive]

steveklein
Posted 26 April 2011 - 04:25 PM

new tornado warnings coming out across arkansas. now 4 separate tornado warnings in arkansas alone.

 

[TW Archive]

ALhurricane
Posted 26 April 2011 - 04:26 PM

steveklein, on 26 April 2011 - 04:24 PM, said:

well, actually... for every dollar the average person puts into insurance, they will get less than a dollar back over the course of their lifetime. you only do it as an insurance to a catastrophic loss... over an infinite sample size, insurance is a bad investment. unfortunately, because of the randomness of catastrophe, we can't take that risk.

I rest my case

 

[TW Archive]

metallicwx366
Posted 26 April 2011 - 04:27 PM

ID Max Top VIL Severe Hail Hail Max Hail Size Speed Direction (from)
1 U0 69 dBZ 37,000 ft. 66 kg/m² 100% chance 100% chance 2.25 in. 31 knots WSW (240)
1 Z0 67 dBZ 50,000 ft. 77 kg/m² 100% chance 100% chance 3.25 in. 33 knots SW (227)
1 M0 66 dBZ 47,000 ft. 84 kg/m² 100% chance 100% chance 3.25 in. 33 knots WSW (243)
K1 66 dBZ 39,000 ft. 74 kg/m² 100% chance 100% chance 2.25 in. 51 knots SSW (205)
1 U2 64 dBZ 40,000 ft. 72 kg/m² 100% chance 100% chance 2.00 in. 37 knots SW (228)
1 I2 61 dBZ 41,000 ft. 49 kg/m² 80% chance 100% chance 1.50 in. 29 knots SSW (196)
2 L0 61 dBZ 16,000 ft. 31 kg/m² 20% chance 20% chance 0.50 in. 23 knots SW (234)
1 D1 60 dBZ 33,000 ft. 48 kg/m² 60% chance 100% chance 1.25 in. 33 knots SSW (210)
E0 59 dBZ 34,000 ft. 44 kg/m² 60% chance 100% chance 1.25 in. 17 knots WSW (237)
1 D3 59 dBZ 7,000 ft. 14 kg/m² 0% chance 0% chance 0.00 in. New Cell
1 Q1 58 dBZ 41,000 ft. 52 kg/m² 60% chance 100% chance 1.00 in. 41 knots SW (214)
1 V2 58 dBZ 23,000 ft. 34 kg/m² 40% chance 70% chance 0.75 in. 37 knots SSW (204)
1 L2 58 dBZ 34,000 ft. 29 kg/m² 10% chance 90% chance 0.50 in. 49 knots SW (232)
2 X1 55 dBZ 42,000 ft. 51 kg/m² NA% chance NA% chance NA in. 33 knots SW (219)
1 T0 54 dBZ 38,000 ft. 21 kg/m² 60% chance 100% chance 1.00 in. 25 knots SW (219)
B3 54 dBZ 21,000 ft. 16 kg/m² 10% chance 80% chance 0.50 in. New Cell
1 R1 54 dBZ 23,000 ft. 26 kg/m² 10% chance 60% chance 0.50 in. 19 knots SSW (206)
1 J1 54 dBZ 27,000 ft. 22 kg/m² 0% chance 70% chance <0.50 in. 25 knots S (189)
2 X2 52 dBZ 17,000 ft. 15 kg/m² 0% chance 10% chance <0.50 in. 45 knots SW (221)
F3 51 dBZ 28,000 ft. 7 kg/m² 30% chance 90% chance 0.50 in. New Cell
1 E2 51 dBZ 23,000 ft. 16 kg/m² 0% chance 40% chance <0.50 in. 29 knots SSW (208)
2 W2 51 dBZ 41,000 ft. 34 kg/m² NA% chance NA% chance NA in. 35 knots W (276)
2 E3 51 dBZ 11,000 ft. 7 kg/m² 0% chance 0% chance 0.00 in. New Cell
2 Y1 50 dBZ 29,000 ft. 20 kg/m² NA% chance NA% chance NA in. 33 knots SSW (208)
1 G3 47 dBZ 36,000 ft. 5 kg/m² 10% chance 100% chance 0.50 in. New Cell
2 H3 47 dBZ 21,000 ft. 4 kg/m² 0% chance 40% chance <0.50 in. New Cell
1 Z2 47 dBZ 27,000 ft. 12 kg/m² 0% chance 10% chance <0.50 in. 43 knots SSW (209)
2 C3 47 dBZ 33,000 ft. 16 kg/m² NA% chance NA% chance NA in. New Cell
1 Y2 47 dBZ 25,000 ft. 9 kg/m² 0% chance 0% chance 0.00 in. 45 knots SW (227)
2 K2 47 dBZ 15,000 ft. 7 kg/m² 0% chance 0% chance 0.00 in. 49 knots SW (222)
2 I3 46 dBZ 8,000 ft. 1 kg/m² 0% chance 0% chance 0.00 in. New Cell

Edited by metallicwx366, 26 April 2011 - 04:28 PM.

 

[TW Archive]

Harlequhn_Boy
Posted 26 April 2011 - 04:31 PM

That part of AR is very rural, but I'd be the storm in Cleveland County has one on the ground.

 

[TW Archive]

ARCC
Posted 26 April 2011 - 04:31 PM

Cleveland county, AR cell could produce a monster any minute now.

 

[TW Archive]

swbamaweather
Posted 26 April 2011 - 04:33 PM
This is from the AFD from Mobile........THE AREA REMAINS UNDER A SLIGHT RISK OF SEVERE THUNDERSTORMS ON
WEDNESDAY...WITH A MODERATE RISK SITUATED JUST NORTH OF THE FORECAST
AREA. THE MODERATE AREA MAY BE EXTENDED FURTHER TOWARD THE SOUTH DUE
TO THE INCREASE IN THE SEVERE WEATHER POTENTIAL AND HIGHER
CONFIDENCE IN THE SEVERE WEATHER PARAMETERS. INSTABILITY WILL
INCREASE WEDNESDAY AFTERNOON WITH MLCAPES BETWEEN 2500 AND 3500
J/KG. A LOW LEVEL JET WILL ALSO INCREASE TO BETWEEN 40 AND 50
KNOTS...AND SURFACE TO 1 KM HELICITY VALUES COULD BE AS HIGH AS 350
M2/S2. DAMAGING WINDS...LARGE HAIL AND DANGEROUS LONG TRACK
TORNADOES ARE ALL POSSIBLE

 

[TW Archive]

Weatherphreak
Posted 26 April 2011 - 04:49 PM

Memphis is in the bullseye for that cluster in SE Arkansas. Looks like there is another torn warned storm that's gonna be close right at rush hour.