Monday, April 30, 2012
..CENTRAL/SOUTHERN PLAINS... WIDESPREAD THUNDERSTORMS HAVE BEEN ONGOING OVERNIGHT ACROSS PARTS OF KS/OK/MO. THESE STORMS HAVE RESULTED IN A WELL-DEFINED OUTFLOW BOUNDARY THAT EXTENDS ROUGHLY FROM AMA-SPS-ADM-FSM. EASTERLY LOW LEVEL WINDS ON THE NORTH SIDE OF THE BOUNDARY WILL HELP TO TRANSPORT AMPLE MOISTURE WESTWARD INTO THE TX PANHANDLE. MOST MODEL SOLUTIONS AGREE ON STORMS FORMING ALONG THE DRYLINE/REMNANT OUTFLOW BOUNDARY BETWEEN 19-22Z...AS A WEAK SHORTWAVE TROUGH NOW NEAR THE 4-CORNERS AREA APPROACHES THE REGION. THE 12Z AMA RAOB ALSO SUPPORTS RATHER EARLY INITIATION WITH STEEP LAPSE RATES AND ONLY A MINIMAL CAP. STRONG DEEP LAYER EFFECTIVE SHEAR AND MEAN FLOW ORTHOGONAL TO DRYLINE WILL PROMOTE DISCRETE SUPERCELL DEVELOPMENT WITH VERY LARGE HAIL POSSIBLE. THE TORNADO POTENTIAL WILL BE DEPENDENT ON THE EVOLUTION OF THE REMNANT OUTFLOW BOUNDARY...BUT THERE DOES APPEAR TO BE SOME RISK OF A FEW TORNADOES DURING THE EVENING FROM SOUTHWEST KS INTO THE TX PANHANDLE AND SOUTHWEST OK. DURING THE EVENING...STORMS MAY GROW UPSCALE AND SPREAD EASTWARD ACROSS PORTIONS OF WESTERN/CENTRAL OK WITH AN CONTINUED RISK OF HAIL AND DAMAGING WINDS.
Posted by Steve Douglass at 9:08 AM
Friday, April 27, 2012
Friday, April 13, 2012
..SRN AND CNTRL PLAINS...
AN IMPRESSIVE UPPER-LEVEL LOW WILL MOVE EWD ACROSS FOUR CORNERS
REGION SATURDAY AS A POWERFUL 90 TO 110 KT MID-LEVEL JET EJECTS NEWD
INTO THE SRN AND CNTRL PLAINS. AHEAD OF THE SYSTEM...A CORRIDOR OF
MODERATE TO STRONG INSTABILITY IS FORECAST ACROSS ECNTRL KS...CNTRL
OK INTO NW TX. THIS COMBINED WITH STEEP MID-LEVEL LAPSE RATES AND
STRONG LOW-LEVEL SHEAR WILL BE VERY FAVORABLE FOR SEVERE STORMS AND
A TORNADO OUTBREAK WILL BE LIKELY ACROSS THE SRN AND CNTRL PLAINS
FROM LATE SATURDAY AFTERNOON LASTING THROUGH THE EVENING AND INTO
THE OVERNIGHT PERIOD.
Posted by Steve Douglass at 9:48 AM
Wednesday, April 11, 2012
Posted by Steve Douglass at 6:30 PM
Posted by Steve Douglass at 5:56 AM
Monday, April 9, 2012
..THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON THROUGH TONIGHT
FOR WRN OK AND NW TX...
...WRN OK/NW TX AREA THROUGH TONIGHT...
A DIFFUSE FRONT EXTENDS FROM NRN OK INTO SW KS...WITH BOUNDARY LAYER
DEWPOINTS OF 56-60 F REPRESENTATIVE OF THE TX/OK WARM SECTOR N OF
I-10. ALOFT...THE LARGE SCALE RIDGE EXTENDS FROM FAR W TX NNWWD TO
THE NRN ROCKIES...THOUGH AN EMBEDDED/SUBTLE SPEED MAX IS EXPECTED TO
CREST THE RIDGE IN CO TODAY AND MOVE SEWD OVER OK TONIGHT. DAYTIME
HEATING/MIXING WILL HELP CONSOLIDATE A DRYLINE ACROSS THE
CENTRAL/ERN TX PANHANDLE THIS AFTERNOON. THE PRIMARY FOCUS FOR
THUNDERSTORM DEVELOPMENT WILL BE THE DRYLINE/FRONT IN ADVANCE OF THE
SUBTLE SPEED MAX THIS AFTERNOON...WITH STORMS EXPECTED TO SPREAD
SEWD ACROSS WRN/CENTRAL OK AND NW TX OVERNIGHT.
MODIFIED FORECAST AND OBSERVED SOUNDINGS SUPPORT AFTERNOON MLCAPE
VALUES NEAR 1500 J/KG AS A RESULT OF THE MODEST LOW-LEVEL MOISTURE
BENEATH MIDLEVEL LAPSE RATES OF 8.5 C/KM. MEANWHILE...VERTICAL
SHEAR PROFILES ARE FORECAST TO BE FAVORABLE FOR SSEWD-MOVING
SUPERCELLS WITH NWLY EFFECTIVE-BULK SHEAR OF 35-45 KT. LOW-LEVEL
SHEAR WILL BE STRONGEST INVOF THE SURFACE FRONT ACROSS NW OK THIS
AFTERNOON...WHERE EFFECTIVE SRH COULD APPROACH 200 M2/S2.
THE GENERAL SCENARIO IS FOR STORMS TO FORM AROUND 21Z NEAR THE
DRYLINE/FRONT INTERSECTION AND THEN SPREAD SEWD THROUGH THE EVENING.
DISCRETE SUPERCELLS WILL BE POSSIBLE WITH THE INITIAL
DEVELOPMENT...WITH AN ATTENDANT RISK FOR VERY LARGE HAIL AND A
COUPLE OF TORNADOES. LATER THIS EVENING INTO TONIGHT...CONVECTION
WILL TEND TO GROW UPSCALE INTO A CLUSTER OR TWO...AIDED BY A 30 KT
SSWLY LLJ AND ASSOCIATED WARM ADVECTION. THE RISK FOR AT LEAST
ISOLATED LARGE HAIL AND DAMAGING WINDS WILL PERSIST WELL INTO
...FAR W TX/SE NM THIS AFTERNOON/EVENING...
BOUNDARY LAYER DEWPOINTS IN THE 40S TO NEAR 50 HAVE SPREAD WWD INTO
FAR W TX/SE NM. THE 12Z EL PASO SOUNDING SUPPORTS THE POTENTIAL FOR
HIGH-BASED STORM DEVELOPMENT THIS AFTERNOON NEAR AND JUST E OF THE
HIGHER TERRAIN. MLCAPE APPROACHING 1000 J/KG AND EFFECTIVE BULK
SHEAR NEAR 25 KT SUGGEST SOME RISK FOR ISOLATED HAIL/STRONG WIND
Posted by Steve Douglass at 6:08 AM
Saturday, April 7, 2012
Friday, April 6, 2012
TX CAPROCK THIS EVENING...
A DRYLINE WILL BECOME BETTER DEFINED THIS AFTERNOON AS MIXING AND
THE LEE TROUGH CONSOLIDATE THE MOISTURE GRADIENT NEAR THE CAPROCK.
THOUGH THERE IS NO CLEAR LARGE SCALE SUPPORT FOR THUNDERSTORM
DEVELOPMENT...L0W-LEVEL ASCENT ALONG THE DRYLINE MAY SUPPORT THE
DEVELOPMENT OF A HIGH-BASED STORM OR TWO THIS EVENING. VERTICAL
SHEAR IS FORECAST TO BE SUFFICIENT FOR SUPERCELLS IN AN ENVIRONMENT
WITH MLCAPE OF 750-1000 J/KG...AND ISOLATED LARGE HAIL AND/OR STRONG
GUSTS WILL BE POSSIBLE. STILL...SPARSE STORM COVERAGE SUPPORTS ONLY
LOW HAIL/WIND PROBABILITIES.
Posted by Steve Douglass at 9:12 AM
Wednesday, April 4, 2012
Tornado-wrecked Dallas begins assessing damage
By PAUL J. WEBER, Associated Press –
ARLINGTON, Texas (AP) — The tornado hurtled toward the nursing home. Physical therapist Patti Gilroy said she saw the swirling mass barreling down through the back door, after she herded patients into the hallway in the order trained: walkers, wheelchairs, then beds.
"It wasn't like a freight train like everybody says it is," said Gilroy, who rounded up dozens to safety at Green Oaks Nursing and Rehabilitation Center. "It sounded like a bomb hit. And we hit the floor, and everybody was praying. It was shocking."
The National Weather Service said as many as a dozen twisters touched down in a wrecking-ball swath of violent weather that stretched across Dallas and Fort Worth. The destructive reminder of a young tornado season Tuesday left thousands without power and hundreds of homes pummeled or worse.
As the sun rose Wednesday over the southern Dallas suburb of Lancaster, one of the hardest hit areas, it was clear that twisters had bounced in and out of neighborhoods, destroying homes at random. Vehicles were tossed like toys, coming to rest in living rooms and bedrooms.
At one house, a tornado had seemingly dipped into the building like an immersion blender, spinning directly down through an upstairs bedroom and wreaking havoc in the family room below before lifting straight back up and away. A grandfather clock leaned slightly but otherwise stood pristine against a wall at the back of the downstairs room that was filled with smashed furniture and fallen support beams.
Despite the intensity of the slow-moving storms, only a handful of people were hurt, a couple of them seriously, and no fatalities were reported as of late Tuesday.
The Red Cross estimated that 650 homes were damaged. Around 150 Lancaster residents stayed in a shelter Tuesday night.
"I guess 'shock' is probably a good word," Lancaster Mayor Marcus Knight said.
The exact number of tornadoes won't be known until surveyors have fanned across North Texas, looking for clues among the debris that blanketed yards and rooftops peeled off slats.
April is typically the worst month in a tornado season that stretches from March to June, but Tuesday's outburst suggests that "we're on pace to be above normal," said National Weather Service meteorologist Matt Bishop.
An entire wing at the Green Oaks nursing home in Arlington crumbled. Stunning video from Dallas showed big-rig trailers tossed into the air and spiraling like footballs. At the Cedar Valley Christian Center church in Lancaster, Pastor Glenn Young said he cowered in a windowless room with 30 children from a daycare program, some of them newborns.
Ten people in Lancaster were injured, two of them severely, said Lancaster police officer Paul Beck. Three people were injured in Arlington, including two Green Oaks residents taken to a hospital with minor injuries, Arlington Assistant Fire Chief Jim Self said.
Gilroy said the blast of wind through Green Oaks lasted about 10 seconds. She described one of her co-workers being nearly "sucked out" while trying to get a patient out of the room at the moment the facility was hit.
Joy Johnston was also there, visiting her 79-year-old sister.
"Of course the windows were flying out, and my sister is paralyzed, so I had to get someone to help me get her in a wheelchair to get her out of the room," she said.
In one industrial section of Dallas, rows of empty tractor-trailers crumpled like soda cans littered a parking lot.
"The officers were watching the tornadoes form and drop," Kennedale police Chief Tommy Williams said. "It was pretty active for a while."
Most of Dallas was spared the full wrath of the storm. Yet in Lancaster, television helicopters panned over exposed homes without roofs and flattened buildings. Residents could be seen walking down the street with firefighters and peering into homes, looking at the damage after the storm passed.
Hundreds of flights into and out of Dallas-Fort Worth International Airport and Dallas Love Field were canceled or diverted elsewhere Tuesday. About 500 flights remained grounded Wednesday, airport officials said.
The storms knocked out power for thousands. Utility Oncor said nearly 14,000 homes and businesses, mainly in the Arlington area, still had no electricity early Wednesday.
Meteorologists said the storms were the result of a slow-moving storm system centered over northern New Mexico.
Dixon reported from Lancaster. Associated Press writers Nomaan Merchant, Terry Wallace and David Koenig in Dallas, Betsy Blaney in Lubbock, Angela K. Brown in Fort Worth and Robert Ray in Lancaster contributed to this report.
Copyright © 2012 The Associated Press. All rights reserved.
Posted by Steve Douglass at 6:14 AM
Monday, April 2, 2012
A TORNADO WATCH WILL LIKELY BE NEEDED FOR PORTIONS OF NWRN TX...THE
ERN OK/TX PANHANDLES...SWRN KS AND WRN OK THIS AFTERNOON AND
MID-AFTERNOON MESOANALYSIS SHOWS A COLD FRONT WAS LOCATED FROM SWRN
KS INTO ERN NM...WHICH IS BEGINNING TO STALL IN RESPONSE TO PRESSURE
FALLS AHEAD OF A POTENT NEGATIVELY TILT MIDLEVEL SHORTWAVE TROUGH. A
DRYLINE ACCOMPANIED BY DEEPENING CUMULUS EXTENDED SWD FROM THE KS
PORTION OF THE COLD FRONT...WHILE A PACIFIC FRONT WAS BEGINNING TO
ENTER W TX. SURFACE TEMPERATURES ALONG THE DRYLINE HAVE WARMED INTO
THE MID 80S...AND DEWPOINTS E OF THE BOUNDARY RESIDE IN THE UPR 50S
TO MID 60S. THE WARM/MOIST AIRMASS LOCATED ACROSS THE WARM SECTOR
COMBINED WITH STEEP MIDLEVEL LAPSE RATES /IN EXCESS OF 8 C PER KM IN
THE 700-500 MB LAYER/ ARE CONTRIBUTING TO A VERY UNSTABLE
ENVIRONMENT...WITH MLCAPE VALUES NEAR 3000 J/KG.
AS THE UPPER DISTURBANCE LIFTS NWD ACROSS THE SRN HIGH PLAINS THIS
AFTERNOON AND EVENING...SHORT-TERM MODEL GUIDANCE INDICATES SURFACE
CYCLOGENESIS WILL RAPIDLY TAKE PLACE OVER NERN NM AND THE TX
PANHANDLE. STRONG LOW-LEVEL SWLY WINDS OVER W TX...POSSIBLY
ACCOMPANYING AN EWD SURGE OF THE PACIFIC FRONT...WILL QUICKLY SPREAD
EWD TOWARD THE DRYLINE...RESULTING IN STRENGTHENING LOW-LEVEL
CONVERGENCE. AS THIS TAKES PLACE...SCATTERED THUNDERSTORM ARE
FORECAST TO DEVELOP FROM THE KS TRIPLE POINT SWD ALONG THE DRYLINE
DURING THE EARLY STAGES OF THIS CONVECTIVE EPISODE
TEMPERATURE-DEWPOINT SPREADS WILL BE NEAR 20F OVER THE WARM
SECTOR...AND MIDLEVEL FLOW/DEEP LAYER SHEAR WILL BE MARGINAL FOR
SUPERCELLS...WHICH MAY NEGATIVELY INFLUENCE THE POTENTIAL FOR
TORNADOES DUE TO EXCESSIVE OUTFLOW. HOWEVER...IF STORMS CAN REMAIN
QUASI-DISCRETE INTO THE EVENING...THEN A COOLER/MORE HUMID BOUNDARY
LAYER COUPLED WITH BACKING/STRENGTHENING 0-1 KM FLOW MAY LEAD TO A
MORE SUBSTANTIAL THREAT OF TORNADOES. OTHERWISE...STORMS WILL POSE A
THREAT FOR VERY LARGE HAIL GIVEN THE PRESENCE OF LARGE BUOYANCY AND
VERY STEEP LAPSE RATES...IN ADDITION TO LOCALLY DAMAGING WIND GUSTS.
Posted by Steve Douglass at 1:15 PM
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