2012 U.S Severe Weather (Videos-Photos-Stats-Forecasts)

[cycloneye]

Updated forecast for Thursday in Deep South

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT WED APR 04 2012

VALID 051200Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE GULF
COASTAL STATES AND FL...

...SYNOPSIS...

CUTOFF UPPER LOW THAT WILL LIKELY BE OVER AR BY 12Z THURSDAY WILL
ADVANCE ESEWD AS IT PHASES WITH AMPLIFYING NRN STREAM TROUGH. AT THE
SURFACE AN E-W ORIENTED FRONT WILL MOVE SLOWLY SWD THROUGH THE TN
VALLEY AND CAROLINAS. COLD FRONT ACCOMPANYING THE UPPER TROUGH WILL
ADVANCE THROUGH THE SERN STATES AND EXTEND FROM A SURFACE LOW OFF
THE CAROLINA COASTS SWWD ALONG THE GULF COASTAL AREA BY THE END OF
THIS PERIOD.

...SERN STATES...

SEVERE THREAT THIS PERIOD REMAINS CONDITIONAL OVER A PART OF THE
EXISTING SLIGHT RISK AREA DUE TO POTENTIAL FOR STORMS TO BE ONGOING
OVER PORTIONS OF CNTRL/SRN MS AND AL WITHIN ZONE OF DPVA JUST AHEAD
OF THE PROGRESSIVE UPPER TROUGH. THESE STORMS WILL EXIST WITHIN AN
ENVIRONMENT CHARACTERIZED BY MODEST MUCAPE AND 35-45 KT EFFECTIVE
WLY UNIDIRECTIONAL SHEAR...BUT WINDS IN THE SFC-3KM LAYER SHOULD
REMAIN RELATIVELY WEAK. THIS ENVIRONMENT WILL BE AT LEAST MARGINALLY
SUPPORTIVE OF STORM ORGANIZATION...AND THE EARLY STORMS COULD POSE
SOME THREAT FOR ISOLATED DAMAGING WIND AND HAIL. EXTENT OF THE EARLY
CONVECTIVE DEVELOPMENT WILL DICTATE DESTABILIZATION POTENTIAL LATER
IN THE DAY...AND ADDITIONAL STORMS MAY DEVELOP ALONG RESIDUAL
OUTFLOW BOUNDARIES AND WHERE SUFFICIENT BOUNDARY LAYER WARMING
OCCURS IN REMAINING PARTS OF WARM SECTOR.

MODEST WLY BOUNDARY LAYER WINDS SHOULD TRANSPORT RICHER LOW LEVEL
MOISTURE INTO THE FL PENINSULA. MID-UPPER FLOW AND VERTICAL SHEAR
WILL STRENGTHEN OVERNIGHT IN ASSOCIATION WITH APPROACHING MID LEVEL
JET WITHIN BASE OF UPPER TROUGH. THUS THE RISK FOR A FEW STRONG TO
SEVERE STORMS WILL INCREASE THURSDAY EVENING OR OVERNIGHT WITH THE
APPROACH OF THE UPPER TROUGH. ISOLATED DAMAGING WIND AND HAIL WILL
BE POSSIBLE WITH THE STRONGER STORMS.



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[cycloneye]

Preliminary Stats of April 3rd event







http://www.srh.noaa.gov/fwd/

[Cyclenall]

Is this like the 15th straight day of Slight Risk? There hasn't been a break of them for a long while now. I can't tell if this is normal or not because I just started monitoring the SPC page since April of last year. Lots of hail days and general severe weather (For total severe weather we might be breaking a record).

I'm sure there was at least one EF4 from yesterday's outbreak...well built homes/structures flattened to the ground (not many) were shown in Royse City TX.

[cycloneye]

Is this like the 15th straight day of Slight Risk? There hasn't been a break of them for a long while now. I can't tell if this is normal or not because I just started monitoring the SPC page since April of last year. Lots of hail days and general severe weather (For total severe weather we might be breaking a record).

I'm sure there was at least one EF4 from yesterday's outbreak...well built homes/structures flattened to the ground (not many) were shown in Royse City TX.

I guess that on Thursday they will have an update about the classifications of the tornadoes of April 3rd. I would have put a Moderate Risk before the April 3rd event began,but I dont work at SPC.

[cycloneye]

Cyclenall and rest of peeps,I think this extraordinary video has not been posted here. Wow! is the word to describe this as the tornado moves over the highway and all traffic stops to avoid the debris.

http://www.youtube.com/watch?feature=pl ... zpuNmhvqN4

[brunota2003]

Love that he was actually silent the whole time, despite the open mic. Crazy actually seeing the circulation on the roadway itself, and to that one driver that decided it would look cool to everyone else if he stopped like 20 or 30 feet away from the main part...it just looks stupid!

[cycloneye]

Love that he was actually silent the whole time, despite the open mic. Crazy actually seeing the circulation on the roadway itself, and to that one driver that decided it would look cool to everyone else if he stopped like 20 or 30 feet away from the main part...it just looks stupid!

Yes,that driver was crazy getting very close to the center of it with the debris swirling around.

[Fyzn94]

This bad boy caught me by surprise. It's a severe thunderstorm that's producing TENNIS BALL-SIZE HAIL.

[CrazyC83]

15 straight days of a risk area is very rare in April. In June or July it is the norm.

[cycloneye]

Forecast of slight Risk for Thursday in the SE U.S

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1236 AM CDT THU APR 05 2012

VALID 051200Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE SERN U.S....

...SERN U.S...

EARLY THIS MORNING WV IMAGERY CLEARLY DEPICTS AN EWD MOVING UPPER
LOW ALONG THE OK/AR BORDER...EAST OF TUL. THIS FEATURE WILL SHIFT
INTO AR THEN DIG SEWD TO A POSITION JUST SW OF MEM BY 18Z. LATEST
SHORT RANGE MODEL GUIDANCE IS IN GENERAL AGREEMENT REGARDING THIS
EVOLUTION WITH A POCKET OF COLD 500MB TEMPERATURES...ON THE ORDER OF
MINUS 18-20C...EXPECTED TO OVERSPREAD AR/NRN MS JUST NORTH OF WELL
DEFINED MID LEVEL JET CORE BY EARLY AFTERNOON. ALTHOUGH LOW LEVEL
MOISTURE IS NOT PARTICULARLY HIGH ACROSS THIS REGION IT APPEARS SFC
DEW POINTS WILL HOLD IN THE 50S PRIOR TO CONVECTIVE OVERTURNING. IN
FACT THUNDERSTORMS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE
PERIOD WITHIN THE EXIT REGION OF UPPER JET OVER AR...POSSIBLY
EXTENDING SEWD TOWARD THE CNTRL GULF COAST WITHIN THE WARM ADVECTION
ZONE. LOW LEVEL CONVERGENCE IS NOT EXPECTED TO BE PARTICULARLY
FOCUSED BUT IN THE ABSENCE OF MEANINGFUL INHIBITION IT WOULD SEEM
PLAUSIBLE THAT CONVECTION SHOULD DEVELOP WITH MINIMAL LOW LEVEL
CONVERGENCE...ESPECIALLY DURING THE HEAT OF THE DAY. FOR THIS
REASON HAVE OPTED TO EXPAND THE SLIGHT RISK TO INCLUDE MUCH OF THE
CNTRL/ERN GULF STATES INTO SC.

LATEST THINKING IS NOTABLE BOUNDARY LAYER HEATING WILL OCCUR EARLY
IN THE PERIOD JUST AHEAD OF THE UPPER LOW OVER AR...ARCING SEWD
ACROSS MS. THIS WILL ENCOURAGE THUNDERSTORM DEVELOPMENT BY LATE
MORNING AS TEMPERATURES WARM INTO THE UPPER 60S. GIVEN THE FORECAST
MID LEVEL JET CORE THAT WILL OVERSPREAD THIS REGION DEEP LAYER SHEAR
WILL CERTAINLY SUPPORT ORGANIZED UPDRAFTS...SOME OF WHICH MAY
ROTATE. HOWEVER...WEAK LOW LEVEL SHEAR SHOULD LIMIT THE SEVERE
THREAT TO LARGE HAIL AND PERHAPS DAMAGING WINDS. AT THIS TIME
FORECAST PROFILES DO NOT LOOK PARTICULARLY FAVORABLE FOR TORNADOES.

ANOTHER FOCUS FOR THUNDERSTORM INITIATION WILL BE ALONG AN OLD
FRONTAL ZONE THAT WILL BE DRAPED FROM SC...NWWD ACROSS NRN GA INTO
MIDDLE TN. STRONG HEATING ALONG THIS BOUNDARY WILL EASILY ALLOW SFC
PARCELS TO REACH THEIR CONVECTIVE TEMPERATURES AND THUNDERSTORMS
WILL EXPAND IN COVERAGE AND INTENSIFY BETWEEN 18-21Z WITHIN AN
ENVIRONMENT OF SIGNIFICANT DEEP LAYER SHEAR BUT WEAK SWLY FLOW
THROUGH 4KM. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN THREATS
WITH THIS ACTIVITY.



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[cycloneye]

Here is another video of those trailers flying with an explanation by Dr Greg Forbes. But my favorite one is what I posted 6 posts back. That was amazing in the highway.

http://video.msnbc.msn.com/nightly-news ... /#46958043

[Ntxw]

I don't know if this video has been posted yet but it's a good one of the Lancaster/Dallas tornado. Amazing no one died with all that debris...

http://www.youtube.com/watch?v=5DZnmliI-aw&feature=related

[cycloneye]

I don't know if this video has been posted yet but it's a good one of the Lancaster/Dallas tornado. Amazing no one died with all that debris...

http://www.youtube.com/watch?v=5DZnmliI-aw&feature=related

I didn't saw this one.Amazing to see the debris swirling around.

[cycloneye]

Slight Risk on Saturday for Northern Texas/WestCentral Texas/Southern Oklahoma

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT FRI APR 06 2012

VALID 071200Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN OK/NRN TX
WSWWD TO WEST CENTRAL TX....

...SYNOPSIS...
AN UPPER TROUGH...CURRENTLY TRACKING THROUGH THE GREAT BASIN...IS
EXPECTED TO MOVE EWD AS A NEGATIVELY-TILTED SYSTEM FROM THE NRN
PLAINS TO THE UPPER GREAT LAKES BY 12Z SUNDAY. AN UPPER RIDGE WILL
REMAIN CENTERED OVER THE SOUTH CENTRAL STATES ON SATURDAY...WHILE A
CLOSED LOW FORMS ALONG THE NRN ATLANTIC COAST INTO SRN QUEBEC AND A
LARGE TROUGH EVOLVES OVER THE ERN PACIFIC APPROACHING THE WEST
COAST.

AT THE SURFACE...A COLD FRONT ATTENDANT TO THE PROGRESSIVE NRN
PLAINS UPPER TROUGH IS FORECAST TO ADVANCE THROUGH THE UPPER AND MID
MS VALLEY AND SWD INTO THE SRN PLAINS. BY 12Z SUNDAY...THIS
BOUNDARY SHOULD EXTEND FROM LAKE HURON SWWD THROUGH THE LOWER OH
VALLEY INTO AR...TO NRN AND FAR SWRN TX.

...SRN OK/NRN TO WRN TX...
WATER VAPOR IMAGERY INDICATED A LOW LATITUDE IMPULSE OVER THE ERN
PACIFIC /CURRENTLY CENTERED OVER 20N/125W/...WITH MODELS IN
AGREEMENT SHOWING THIS SYSTEM TO MOVE FROM NRN MEXICO TO NRN/CENTRAL
TX DURING DAY 2.

ELEVATED TSTMS ARE EXPECTED TO BE ONGOING AT 12Z SATURDAY FROM NRN
OK THROUGH ERN KS TO SERN NEB WITHIN A LOW LEVEL WAA REGIME
ATTENDANT TO A 40-50 KT SWLY LLJ EXTENDING NEWD FROM NWRN TX.
DESPITE MODERATE ELEVATED INSTABILITY AND STEEP MIDLEVEL LAPSE
RATES...WEAK BULK SHEAR IS EXPECTED TO LIMIT HAIL SIZE WITH THIS
ONGOING ACTIVITY AT THE START OF DAY 2. THE LLJ WILL WEAKEN AS IT
VEERS TO WLY WITH THE ONGOING CLUSTER OF STORMS SHIFTING SEWD INTO
ERN OK TO SWRN MO/NWRN AR SATURDAY MORNING. SIMILAR CAPE/SHEAR
PARAMETER SPACE WILL PRECLUDE A SEVERE WEATHER THREAT.

A GREATER SEVERE WEATHER THREAT IS POSSIBLE SATURDAY AFTERNOON/
EVENING ACROSS SRN OK/NRN TX AND WSWWD INTO WRN TX AS MODERATE
INSTABILITY DEVELOPS ALONG AND S OF THE COLD FRONT MOVING INTO THIS
REGION. ALTHOUGH LOW LEVEL WINDS/SHEAR WILL BE RATHER WEAK..30-40
KT WSWLY MIDLEVEL WINDS WILL CONTRIBUTE TO EFFECTIVE BULK SHEAR OF
30-35 KT TO SUPPORT A MULTICELL STORM MODE. CONVERGENCE ALONG THE
COLD FRONT AND SURFACE HEATING WEAKENING INHIBITION WILL SUPPORT
TSTM DEVELOPMENT WSWWD FROM THE RED RIVER. STEEP MIDLEVEL LAPSE
RATES SUGGEST HAIL WILL BE THE PRIMARY THREAT WITH GUSTY WINDS ALSO
POSSIBLE. ADDITIONAL STORMS WILL BE POSSIBLE INTO FAVORABLE UPSLOPE
REGIME OVER SWRN TX.

..PETERS.. 04/06/2012

[CrazyC83]

At least the first half of April 2012 appears to be nowhere near what April 2011 was. Next chance for an outbreak looks to be late next week - a Friday the 13th outbreak?

[Cyclenall]

I guess that on Thursday they will have an update about the classifications of the tornadoes of April 3rd. I would have put a Moderate Risk before the April 3rd event began,but I dont work at SPC.

I think a lot of people would have put a Moderate up but hindsight is 20/20. On a different note, why was the Royse City TX tornado rated an EF2? A well built home flattened to the ground doesn't sound like it to me. To add, a lot of those tornadoes captured on camera seem way stronger then the ratings show, it goes back to that question of whether it was at its strongest during locomotion over property.

Cyclenall and rest of peeps,I think this extraordinary video has not been posted here. Wow! is the word to describe this as the tornado moves over the highway and all traffic stops to avoid the debris.

http://www.youtube.com/watch?feature=pl ... zpuNmhvqN4

I saw that, absolutely incredible debris footage. There are actually two videos from that same highway and angle but the HD one catches the debris in much better detail and its zoomed. Maybe in the top 10 for best debris footage of tornadoes sub-category for me.

Love that he was actually silent the whole time, despite the open mic. Crazy actually seeing the circulation on the roadway itself, and to that one driver that decided it would look cool to everyone else if he stopped like 20 or 30 feet away from the main part...it just looks stupid!

The circulation was like a mini-category 4 hurricane on land. That one driver who kept getting closer to it is getting so much heat over these videos...I wonder if the driver has seen any of this? It would be cool but dangerous. Some suspect he/she didn't know what they were looking at so they weren't careful .

15 straight days of a risk area is very rare in April. In June or July it is the norm.

Interesting to know. The "15" straight days is just an estimate but a lot of that was in March too.

I don't know if this video has been posted yet but it's a good one of the Lancaster/Dallas tornado. Amazing no one died with all that debris...

http://www.youtube.com/watch?v=5DZnmliI-aw&feature=related

Didn't see this one. Another incredible one, so much debris in the air for an "EF2". Rare to see an "EF2" look that good at times . It could have been shot better with the zooming and getting out of the vehicle, etc. He mentioned that it was his first time and maybe nervous so its not perfect.

At least the first half of April 2012 appears to be nowhere near what April 2011 was. Next chance for an outbreak looks to be late next week - a Friday the 13th outbreak?

Let me guess, a cold outbreak comes with this supposed possible event? Its like you can't get nice heat and severe weather outbreaks on a grand scale at once, because of the high location getting in the way. I'm talking about southern Ontario here though.

[somethingfunny]

At least the first half of April 2012 appears to be nowhere near what April 2011 was. Next chance for an outbreak looks to be late next week - a Friday the 13th outbreak?

It is Sprint Cup weekend at Texas Motor Speedway. They're on a roll with tornado warnings there lately...

[cycloneye]

Day 4-8 Outlook issued on 4/7/12

May be a big outbreak in this period if all the factors are right. Crazy,what do you think?

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT SAT APR 07 2012

VALID 101200Z - 151200Z

...DISCUSSION...
MEDIUM RANGE MODELS REMAIN IN GENERAL AGREEMENT EARLY IN THE
EXTENDED OUTLOOK PERIOD...SHOWING A LONGWAVE TROUGH LINGERING OVER
THE ERN STATES THROUGH D5/WED. MEANWHILE...THE ROCKIES RIDGE WILL
SHIFT EWD INTO THE CENTRAL STATES...WHILE THE UPSTREAM ERN PACIFIC
TROUGH ADVANCES INLAND SUPPORTED BY A PROGRESSIVE BASAL SHORTWAVE
TROUGH APPROACHING SRN CA BY THE START OF D5/WED. THIS LATTER
SYSTEM WILL MOVE THROUGH THE FOUR CORNERS TO CENTRAL HIGH PLAINS ON
D5 BREAKING DOWN THE RIDGE OVER THE HIGH PLAINS.

REGIONAL SEVERE WEATHER THREAT AREAS /30 PERCENT OR GREATER/ ARE NOT
EXPECTED ON D4/TUE OR D5/WED...THOUGH SOME SEVERE STORMS CAN BE
EXPECTED ON D4 ACROSS THE SRN PLAINS...SIMILAR TO WHAT IS EXPECTED
ON D3/MON. SEVERE STORMS WILL ALSO BE POSSIBLE ON D5 OVER THE SRN
AND CENTRAL HIGH PLAINS...BUT LIMITED MOISTURE RETURN WITH NWD
EXTENT SHOULD PRECLUDE THE NEED FOR A REGIONAL SEVERE WEATHER
THREAT.

ALTHOUGH THE GFS/ECMWF DIFFER IN THE TRACK OF THE D4/D5 BASAL
SHORTWAVE TROUGH AS IT EMERGES INTO THE PLAINS WITH THE GFS
MAINTAINING A MORE NRN BIAS...EACH MODEL SHOWS STRONGER SWLY FLOW
ACROSS OK/KS DURING D6/THU ATOP STRONGER SLY LLJ. THESE FAVORABLE
WIND FIELDS/DEEP LAYER SHEAR COMBINED WITH MODERATE INSTABILITY
GIVEN MOISTURE RETURN SUPPORTS A REGIONAL SEVERE WEATHER THREAT AREA
ON D6/THU ACROSS MUCH OF OK INTO CENTRAL AND ERN KS.

BEYOND D6...MODELS ARE SUGGESTING ANOTHER ACTIVE SEVERE WEATHER DAY
COULD DEVELOP ON D8/SAT ACROSS THE SRN PLAINS INTO KS AS THE NEXT
PACIFIC TROUGH ADVANCES INLAND INTO THE PLAINS...BUT TIMING
DIFFERENCES PRECLUDES INTRODUCING ANOTHER REGIONAL SEVERE WEATHER
THREAT AREA.

..PETERS.. 04/07/2012

[cycloneye]

Day 4-8 Outlook issued on 4/8/12

Day 5 will be with a big event if all pans out so watch for that.

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT SUN APR 08 2012

VALID 111200Z - 161200Z

...DISCUSSION...
ALTHOUGH MEDIUM RANGE MODELS /00Z ECMWF AND GFS/ DIFFER IN THE TRACK
OF A TROUGH INTO THE CENTRAL U.S. ON D5/THU AND TO SOME DEGREE ON
D7/SAT...THESE MODELS DO AGREE IN A PATTERN CHANGE ACROSS THE CONUS
FROM MID WEEK TO NEXT WEEKEND. A BLOCKING PATTERN WITH A NWLY FLOW
REGIME OVER THE CENTRAL TO SERN U.S. WILL PERSIST INTO D4/WED WITH A
THREAT FOR SEVERE STORMS ACROSS THE SRN AND CENTRAL HIGH PLAINS.
THE PATTERN CHANGE BEGINS ON D5 AS SWLY FLOW DEVELOPS INTO THE
PLAINS DOWNSTREAM OF A LONGWAVE TROUGH EVOLVING OVER THE WRN STATES
THROUGH THE REST OF THE EXTENDED PERIOD.

FOR D5/THU...THE GFS AND ECMWF CONTINUE TO DIFFER WITH THE TRACK OF
THE SHORTWAVE TROUGH FROM LATE D4/WED THROUGH D5. ALTHOUGH THE GFS
IS MAINTAINING A NRN TRACK BIAS WITH WEAKER FORCING ACROSS
KS/OK...THE WARM SECTORS IN EACH MODEL ARE SIMILAR. NORMALLY THESE
TYPES OF MODEL VARIANCES IN THE MID-UPPER LEVELS WOULD RESULT IN NOT
INCLUDING A REGIONAL SEVERE WEATHER THREAT AREA. HOWEVER...GFS
FORECAST SOUNDINGS SUGGEST THE POTENTIAL FOR SUPERCELLS ALONG THE
DRY LINE...BUT WITH LOWER COVERAGE. THIS FACTOR COMBINED WITH THE
FORECAST FOR STRONGER WIND FIELDS PER THE ECMWF SUGGESTS THE
REGIONAL SEVERE WEATHER THREAT AREA WILL BE MAINTAINED INTO D5 WITH
THE POTENTIAL FOR LARGE HAIL AND TORNADOES.

THE MODEL DIFFERENCES WITH THE TRACK OF THE D5/THU TROUGH AFFECT THE
SEVERE WEATHER FORECAST FOR D6/FRI...WITH THE GFS FAVORING A MORE
NRN TRACK ACROSS KS/NEB INTO IA...WHILE THE ECMWF INDICATED A
GREATER THREAT FARTHER TO THE SSE.

FOR D7/SAT...THE GFS/ECMWF ARE IN BETTER AGREEMENT AGAIN WITH
RESPECT TO THE DISTRIBUTION OF LOW LEVEL MOISTURE AND WARM SECTOR
SETUP ACROSS TX INTO KS. GREATEST JUXTAPOSITION OF INSTABILITY AND
STRONG DEEP LAYER SHEAR SUPPORTS ANOTHER REGIONAL SEVERE WEATHER
THREAT AREA SIMILAR TO D5 ACROSS OK/KS.

..PETERS.. 04/08/2012

[CrazyC83]

If wording gets stronger, a new thread might be warranted. However, I don't like creating threads until the threat is significant and well established.

It does look like a significant Southern Plains outbreak on Thursday is possible. But it is fairly early in the season for that area, and things are more likely to go wrong on April 12 than on May 12, since it can be harder for the atmosphere to reload if early activity takes place.