Particularly dangerous situation (PDS) tornado watch issued, explosive supercells imminent

UPDATE:  7PM EDT  MONSTER TORNADO on LIVE WEBSTREAMING near Norman OK

STREAMING LINK

Update by Ryan Maue

A Particularly Dangerous Situation (PDS) tornado watch (#356) has just been issued for Central Oklahoma and North Central Texas including DFW and OKC.

DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER...

THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE

POSSIBLE IN THESE AREAS.

Tornado likelihood is very high…  SPC Convective Outlook:

...CENTRAL/SOUTHERN PLAINS...

MORNING SATELLITE LOOPS SHOW A VIGOROUS AND PROGRESSIVE MID/UPPER

LEVEL SHORTWAVE TROUGH OVER THE SOUTHERN ROCKIES. THIS FEATURE IS

FORECAST TO ROTATE RAPIDLY EASTWARD INTO THE PLAINS AND BECOME

NEGATIVELY-TILTED THIS EVENING. LATEST TCC PROFILER DATA SHOWS 90+

KNOT FLOW AT 6KM...INDICATIVE OF THE MID/UPPER LEVEL WIND MAX THAT

WILL NOSE INTO THE PLAINS THIS EVENING. MEANWHILE... SOUTHERLY LOW

LEVEL WINDS WILL MAINTAIN UPPER 60S AND LOWER 70S DEWPOINTS ACROSS

MUCH OF NORTH TX...OK...AND SOUTHERN/CENTRAL KS. BY MID AFTERNOON

THE DRYLINE WILL EXTEND FROM WEST-CENTRAL KS INTO WESTERN OK AND

WESTERN NORTH TX. STRONG HEATING AND RICH MOISTURE...COUPLED WITH

NEAR DRY-ADIABATIC MID LEVEL LAPSE RATES...WILL YIELD AN EXTREMELY

UNSTABLE AIR MASS WITH MLCAPE VALUES OF 4000-4500 J/KG.

PRESENT INDICATIONS AND LATEST OPERATIONS/MESOSCALE MODEL GUIDANCE

INDICATE THAT DISCRETE SUPERCELL THUNDERSTORMS WILL FORM ALONG THE

KS/OK DRYLINE BY MID AFTERNOON AND MOVE RAPIDLY NORTHEASTWARD WITH A

RISK OF A FEW TORNADOES AND VERY LARGE HAIL. EARLY IN THE

EVENT...THE GREATEST TORNADO THREAT WILL BE OVER KS AS STORMS

INTERACT WITH PRE-EXISTING OUTFLOW BOUNDARY AND BACKED LOW LEVEL

WINDS.

AS THE AFTERNOON PROGRESSES...CONTINUED HEATING AND LARGE SCALE LIFT

DUE TO APPROACHING UPPER TROUGH MAY LEAD TO MULTIPLE ROUNDS OF

CONVECTIVE DEVELOPMENT ALONG THE DRYLINE. THESE STORMS WILL ALSO

TRACK ACROSS THE HIGH RISK AREA DURING THE EVENING. LOW LEVEL WINDS

WILL BE STRENGTHENING...WITH ALL CONDITIONS FAVORING THE

POTENTIAL FOR LONG-TRACKED STRONG/VIOLENT TORNADOES AND

VERY LARGE HAIL OVER PORTIONS OF NORTH TX...CENTRAL OK...AND

CENTRAL KS

Real-time Forecast Links:

Tornado Probability -- Outlook issued 1625z May 24, 2011

NCEP 4-km Radar Forecast from two versions of the WRF model (ARW and NMM cores):  48-hour animation initialized at 12:00z on May 24, 2011 (from Ryan Maue’s FSU website)

============================================================== UPDATE: I’ve added my own radar product for people to watch, click the image to animate it: If you want to track storms at the local level, download a free copy of StormPredator

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MarkW
May 24, 2011 11:10 am

Can’t buy a freaking break this year.

May 24, 2011 11:31 am

Anthony, do you really think this is happening? I’m in the middle of it, and I just aint seeing it. Of course, bad things can happen fast. I’m keeping my eyes (and ears) open.
[ryanm: yes, keep an eye to the skies]

Douglas DC
May 24, 2011 11:35 am

Not good. Not good at all…

James Sexton
May 24, 2011 11:37 am

We’re all holding our breath in SE KS and SW MO. Here’s to hoping these models are just as effective as most climate scientists’.
P.S. Anthony, you got the link messed up to Ryan’s site, you put the “r” on the other side of the forward slash.

SteveSadlov
May 24, 2011 11:37 am

The cold pool conveyor belt just keeps on giving. The Joplin storm was our storm from mid week last week. Today’s dirty weather is the wave that came through late in the week. The storm that will hit us tomorrow will be a real trouble maker in the S. Plains. There is another one for Memorial Day weekend and another early the following week. No end of pain in sight.

May 24, 2011 11:41 am

Anthony or Ryan, I’ll add that our local weathermen (who are among the best in the world for these situations) are still warning strongly, though odds are only around 50/50. Still, this from one local: “wind gusts of 55 to 75 mph and nearly baseball-sized hail.” Still, from what I see so far, I’m optimistic that it will not get bad. (But what do I know. I’m a metallurgist, not a meteorologist.)

Lance
May 24, 2011 11:45 am

Lets pray that people are given enough time to cover and few people injuried.

May 24, 2011 11:49 am

Noticed that; I’m in the SE corner of that PDS watch box too.
The corresponding, preceding Mesoscale Discussion issued at 12:18 PM CDT:
http://www.spc.noaa.gov/products/md/md0925.html
AREAS AFFECTED…NW TX…WRN AND CNTRL OK
CONCERNING…SEVERE POTENTIAL…TORNADO WATCH LIKELY
VALID 241718Z – 241845Z
STORM INITIATION IS EXPECTED ACROSS WRN OK AND NW TX OVER THE NEXT HOUR. SUPERCELLS SHOULD RAPIDLY DEVELOP WITH A THREAT FOR LARGE HAIL AND TORNADOES. A TORNADO WATCH WILL LIKELY NEED TO BE ISSUED BY 18Z.
SFC ANALYSIS SHOWS A 997 MB LOW IN THE NRN TX PANHANDLE WITH A DRYLINE EXTENDING SWD FROM THE LOW ACROSS FAR WRN OK INTO WEST TX. THE DRYLINE IS STARTING TO ADVANCE EWD WITH VISIBLE SATELLITE IMAGERY SHOWING AN EXPANDING FIELD OF CUMULUS FROM I-40 IN WRN OK SWD TO NEAR SAN ANGELO IN WCNTRL TX. AS FURTHER DESTABILIZATION OCCURS THIS AFTERNOON AND THE CAP WEAKENS … RAPID CELL INITIATION IS EXPECTED TO OCCUR ALONG THIS CORRIDOR. AS THIS OCCURS…A 50 TO 65 KT MID-LEVEL JET EJECTING NEWD TOWARD THE SRN PLAINS WILL CREATE STRONG DEEP LAYER SHEAR PROFILES VERY FAVORABLE FOR SUPERCELLS. AS STORMS INTENSIFY … VERY LARGE HAIL GREATER THAN 2 INCHES IN DIAMETER WILL BECOME LIKELY. IN ADDITION … A 30 TO 40 KT LOW-LEVEL JET IS IN PLACE ACROSS NW TX AND WRN OK. AS THIS FEATURE STRENGTHENS…LOW-LEVEL SHEAR WILL BECOME VERY FAVORABLE FOR TORNADOES. WITH 0-3 KM STORM RELATIVE HELICITIES INCREASING INTO THE 450 TO 600 M2/S2 RANGE … LONG-TRACK STRONG TORNADOES ARE EXPECTED TO OCCUR LATE THIS AFTERNOON INTO EARLY THIS EVENING.
..BROYLES.. 05/24/2011
.

May 24, 2011 11:55 am

Also, the 1633z / 1:33 PM CDT surface map: http://oi53.tinypic.com/11gsz2f.jpg
Dew points round about 70’s throughout the corridor defined for the watch …
.

reason
May 24, 2011 12:07 pm

I should’ve been a storm-chaser.

Darkinbad the Brightdayler
May 24, 2011 12:20 pm

Keep your heads down guys, Climate change may or may not kill your grandchildren but you’ve got to live long enough to have them!

reason
May 24, 2011 12:24 pm
Robert M
May 24, 2011 12:24 pm

Any tornado is bad, don’t get me wrong, but we really need to catch a break with these awful F3+ long duration storms. It is one thing to hunker down in an inner room or hallway when a “little” (Heh, the only little tornadoes are ones you are not in…) one hits, (been there done that, no scars except on my psyche…;-) ) but these huge half mile+ wedge tornadoes are simply not survivable in many cases as we have sadly seen.
If you are under the gun, good luck and stay close to a basement somewhere!

May 24, 2011 12:35 pm

From OKC, it has begun. Pop-ups increasing west of Lawton and north, both sides of I-40. We could be in for a bumpy ride.

Common Sense
May 24, 2011 12:38 pm

Best real-time source:
http://www.wunderground.com/wundermap

May 24, 2011 12:38 pm

And … we have ignition along the dryline in Oklahoma –
Visible sat image 1915z / 2:15 PM CDT – http://oi51.tinypic.com/jauayp.jpg
.

BenfromMO
May 24, 2011 12:40 pm

This is not looking good…the only thing I think OK, SW MO and SE KS can hope for really at this point is that the tornadoes do what they did in St. Louis and skip the killing and just destroy property. That or land somewhere where people are not at…..

May 24, 2011 12:42 pm

For Central Oklahoma, these guys are what I depend on:
http://www.news9.com/category/167025/weather-storm-tracker
http://www.4warn.com/

May 24, 2011 12:44 pm

Thanks Ryan M.
Right now (2:40 CDT) it’s warm (82°F), windy (25 mph), humid (69%), and the pressure (29.60 in.) is falling. Everything’s right for thunderstorms and tornadoes.
I’ve been keeping up with the radar at:
http://radar.weather.gov/radar.php?rid=TLX&product=N0R&overlay=11101111&loop=yes
Wish I had Athony’s weather app (http://www.stormpredator.com/index.htm). And a TV to run it on.
OK S.

May 24, 2011 12:45 pm

Ryan, maybe my Java needs to be updated, but I am not getting your links to work.

May 24, 2011 12:45 pm

19:37z / 2:37 PM CDT Fredrick (FDR) .5 deg 124 nmi WSR-88D image:
http://oi53.tinypic.com/w8tkld.jpg
I see T-storm ignition has taken place in Texas on this one too …

clype
May 24, 2011 12:45 pm
May 24, 2011 12:47 pm

MarkW says on May 24, 2011 at 11:10 am:
Can’t buy a freaking break this year.

The upside is, Mark, “We’ve got rain!” (we’ve been in a bit of drought for awhile in Tejas)
.

May 24, 2011 1:01 pm

13:54 mountain time Dodge City Ks radar is showing some 68-70 dbz cells, one is tracking just south of Garden City. Looks like there will be some healthy storm development if they are getting returns like that this early in the day.
There are another pair of strong cells that on their current track (if they live that long) will track through the Wichita Ks area.
Eastern Colorado has a strong group of storms near the Colorado Kansas border.
It looks like the severe storms folks will have a busy day.
Current storm tracks are from the south west to the north east. Current development is in the west end of Oklahoma, Kansas area and the extreme east part of Colorado.
Larry

clype
May 24, 2011 1:05 pm

Dodge City doppler showing tornado, severe thunderstorm and flash flood warnings.

May 24, 2011 1:16 pm

FYI if anyone wants to pay a small fee for the direct radar feed without delay, I recommend weathertap.com I have no association with them other than I am a subscriber and have used their products to watch storm development when I was storm chasing.
http://www.weathertap.com/
The free radar products you get on the web are usually delayed about 15 minutes from real time, and during a potential severe storm event like this, it is nice to see the radar scans as they update and be able to look at various tilt levels and even the doppler return wind speeds.
Larry
REPLY: StormPredator, linked in the body of the message, at http://www.stormpredator.com offers a free data feed, direct from NWS with no delay. Has all the products. You can also track storms with it and get ETA’s as well as RT watch/warning overlays – Anthony

May 24, 2011 1:19 pm

Gary England on Channel 9 out of Oklahoma City is showing (at 2:15 CDT) a live video of a tornado out by Canton, OK. A small one so far.
OK S.

May 24, 2011 1:21 pm

So far, none of these are “right-movers” (from the mean wind) – not even the T-storm to the west of Dodge City.

Supercells are usually found isolated from other thunderstorms, although they can sometimes be embedded in a squall line. Because they can last for hours, they are known as quasi-steady-state storms.
Supercells have the capability to deviate from the mean wind. If they track to the right or left of the mean wind (relative to the vertical wind shear), they are said to be “right-movers” or “left-movers,” respectively.
http://en.wikipedia.org/wiki/Supercell

And Ryan, your links and animation worked for me w/Opera 11.x as the browser.
.

May 24, 2011 1:28 pm

Just watch one of the storm chaser choppers catch a small tornado touchdown. It is dark now. So far, tracks are heading north of the OKC metro, but it is looking like it is only beginning. We cleaned out the storm cellar this morning. The kids are ready.

James Sexton
May 24, 2011 1:30 pm

Lonnie E. Schubert says:
May 24, 2011 at 12:45 pm
Ryan, maybe my Java needs to be updated, but I am not getting your links to work.
======================================================
I sent the link to some colleagues, and its happening to them to. I use FF w/o any problems, but it won’t run on my IE either………. anyone got any ideas?

May 24, 2011 1:30 pm

Sorry, that should have been 3:15 CDT and there’s a quarter-mile wide tornado on the ground, also, east of Canton. No more updates, I promise.
OK S.

May 24, 2011 1:33 pm

HEADS UP – Mesoscale Discussion concerning Central Texas
Note in particular the discussion about the ‘cap’ (capping inversion Cinh) being gone and the mid-level jet.
http://www.spc.noaa.gov/products/md/md0930.html
MESOSCALE DISCUSSION 0930
NWS STORM PREDICTION CENTER NORMAN OK
0215 PM CDT TUE MAY 24 2011
AREAS AFFECTED…ERN PARTS OF THE CONCHO VALLEY INTO CNTRL TX
CONCERNING…SEVERE POTENTIAL…TORNADO WATCH LIKELY
VALID 241915Z – 242045Z
A SEVERE THREAT WILL LIKELY DEVELOP ACROSS THE CONCHO VALLEY INTO CNTRL TX THIS AFTERNOON. AS CELLS INITIATE … SUPERCELL DEVELOPMENT WILL LIKELY OCCUR WITH A POTENTIAL FOR LARGE HAIL AND TORNADOES. A TORNADO WATCH WILL LIKELY BE NECESSARY OVER THE NEXT HOUR ACROSS THE REGION.
A DRYLINE IS CURRENTLY LOCATED ACROSS WEST TX AND IS STARTING TO ADVANCE MORE QUICKLY EWD. VISIBLE SATELLITE IMAGERY SHOWS CUMULUS JUST AHEAD OF THE DRYLINE FROM NEAR WICHITA FALLS SWD TO NEAR SAN ANGELO.
THE CAPPING INVERSION IS NOW GONE ACROSS THE MCD AREA AND STORM INITIATION WILL BECOME INCREASINGLY LIKELY AS CONVERGENCE INCREASES ALONG THE DRYLINE. MESOANALYSIS SHOWS STRONG INSTABILITY IN PLACE WITH MLCAPE VALUES FROM 3000 TO 4000 J/KG.
IN ADDITION…PROFILER DATA SUGGEST 0-6 KM SHEAR VALUES ARE AROUND 40 KT. THE SHEAR SHOULD RAPIDLY INCREASE AS A 65 TO 80 KT MID-LEVEL JET MOVES INTO THE REGION FROM THE WEST MAKING CONDITIONS VERY FAVORABLE FOR SUPERCELLS. THE MORE DOMINANT SUPERCELLS SHOULD HAVE A THREAT FOR VERY LARGE HAIL OF GREATER THAN 2 INCHES IN DIAMETER. IN ADDITION … STRENGTHENING LOW-LEVEL SHEAR LATE THIS AFTERNOON SHOULD ALSO RESULT IN A TORNADO THREAT WITH AN ISOLATED STRONG TORNADO THREAT POSSIBLE AS WELL.
..BROYLES.. 05/24/2011
.

May 24, 2011 1:51 pm

Also note, Ryan, they have extended PDS TW #356 further south; it now includes Stephenville (former site of the WSR-57 that used to cover our area) for instance:
http://www.spc.noaa.gov/products/watch/ww0356.html
http://www.spc.noaa.gov/products/watch/ww0356_radar_big.gif
.

May 24, 2011 2:07 pm

Interesting to note the original development along the dry line in Texas has ‘leapfrogged’ ahead with the original line dissipating … we now have activity only two counties west of Ft. Worth that showed development about 3:30 PM CDT with intensification by 3:45 PM.
No ‘right-movers’ noted yet either in any of these storms as of about 10 min ago …
.

Garry
May 24, 2011 2:21 pm

The NEXRAD is looking pretty ugly at 5:19PM EDT (you can turn on animation at the link):
http://www.wunderground.com/radar/radblast.asp?ID=OKC

May 24, 2011 2:24 pm

Maybe a good time to review “Tornado Alley” :
http://en.wikipedia.org/wiki/Tornado_Alley
Cutting to the chase, for those that just want the map:
http://upload.wikimedia.org/wikipedia/commons/3/35/Tornado_Alley.gif
.

May 24, 2011 2:39 pm

Noting a couple cells in Texas and Oklahoma with some right-moving tendencies, but nothing outstanding.
When one SEES a strong right-mover, it will be quite apparent … it is a site to behold to see a singular cell moving in a direction not in accord with the other, nearby cells or with the squall line …
ON THE MOTION AND INTERACTION BETWEEN LEFT- AND RIGHT-MOVING SUPERCELLS noaa.gov pdf file
The Tornado: its structure, dynamics, prediction, and hazards Google Book
Safest, best parts of storms, to see tornado? forum posting; disc about right-movers
.

May 24, 2011 2:47 pm

Good right-mover can be seen NNW of DDC WSR-88D at 2145z / 4:45 PM CDT …
Pick a 1 hr loop on the RADAR imagery supplier of your choice.
.

May 24, 2011 2:55 pm

Tornados on the ground in OKC metro.

May 24, 2011 3:04 pm

Mike Morgan (KFOR) just said there is a supercell right where the May third tornado was! It is bad here.

May 24, 2011 3:08 pm

Hate to be a thread hog, but … the tail-end Charlie cell in the line in Texas is a right-mover and Dan Henry CH 4 met says will be in metroplex by 5:30 PM CDT …
Attributes of pendant echo (a hook) are evident as well and confirmed by Doppler TVS signature algo.
.

May 24, 2011 3:16 pm

Mods/Anthony, if this is getting to be too much, let me know …
New MD for this PDS watch box – http://www.spc.noaa.gov/products/md/md0934.html
Note in particular bolded text regarding unstable atmosphere and the ‘moist’ boundary layer.
MESOSCALE DISCUSSION 0934
NWS STORM PREDICTION CENTER NORMAN OK
0448 PM CDT TUE MAY 24 2011
AREAS AFFECTED…CNTRL OK THROUGH N-CNTRL TX
CONCERNING…TORNADO WATCH 356…
VALID 242148Z – 242315Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 356 CONTINUES.
SUPERCELLS CAPABLE OF PRODUCING STRONG TO VIOLENT TORNADOES AND VERY LARGE HAIL WILL MOVE INTO CNTRL OK AND N-CNTRL TX … LIKELY AFFECTING THE OKLAHOMA CITY AND DALLAS-FORT WORTH METRO AREAS BETWEEN 5 AND 7 PM THIS EVENING. GREATEST THREAT CURRENTLY APPEARS ACROSS CNTRL AND S-CNTRL OK.
A LINE OF DISCRETE SUPERCELLS THAT INITIATED ALONG THE DRYLINE EXTENDS FROM NEAR ENID IN N-CNTRL OK SWD TO NEAR MINERAL WELLS IN N-CNTRL TX.
THE DOWNSTREAM ATMOSPHERE IS VERY UNSTABLE WITH 3000-4000 J/KG MLCAPE … VERY STEEP LAPSE RATES AND A MOIST BOUNDARY LAYER.
THE TWIN LAKES VWP ALREADY INDICATE VERY STRONG /60-70 KT/ SFC-6 KM SHEAR AND LARGE HODOGRAPHS WITH 300+ M2/S2 0-1 KM STORM RELATIVE HELICITY.
SEVERAL TORNADOES HAVE ALREADY BEEN CONFIRMED…AND THIS PARAMETER SPACE WILL CONTINUE TO SUPPORT SUPERCELLS CAPABLE OF LONG TRACK … DAMAGING TORNADOES AND VERY LARGE HAIL AS STORMS MOVE THROUGH CNTRL OK AND N-CNTRL TX NEXT FEW HOURS.
..DIAL.. 05/24/2011
.

P Walker
May 24, 2011 3:30 pm

Just checked OKC with my Storm Predator software . Look out folks . Same for you in Salina KS .

May 24, 2011 3:32 pm

Didn’t see if it was posted but, here is a link to Gary England and News9 live streaming coverage in Oklahoma:
http://www.news9.com/category/184600/severe-weather-embedded-live-stream-kwtv1?redirected=true

May 24, 2011 3:39 pm

Live streaming from KFOR:
http://www.kfor.com/news/livestreaming/

May 24, 2011 3:46 pm

“Debris Ball” on RADAR picked up off of KFOR video stream 5:45 PM CDT:
http://oi54.tinypic.com/w89aic.jpg

May 24, 2011 3:57 pm

This storm is spinning on the KS-CO border, and dragging a tail up into it from DFW through OKC to ITC. Wow. Big tornado headed our way, but probably will stay south of us. We have significant hail, and it is getting bigger. Mom and the kids are in the cellar. I’m watching Gary England and Mike Morgan.

May 24, 2011 3:58 pm

A “Grinder” reported by KFOR live stream:
http://oi53.tinypic.com/2ypkb4k.jpg
North side of Washington and heading for Noble …

May 24, 2011 4:02 pm

Grinder (as they called it on-air) w/enhanced contrast:
http://oi53.tinypic.com/2vdsnxf.jpg
about 6 PM CDT from KFOR stream
.

May 24, 2011 4:05 pm

Radar sez the “tail-end-charlie” cell has passed me on its way to DFW, and the sky outside agrees. I got a little 1-cm. hail.
The radar also shows something I’ve seen before and don’t understand. Off in west Texas and eastern New Mexico there are points that are centers for cloud formation, with the clouds then streaming off to the east and getting bigger, almost like smoke from a stack. I haven’t checked between times if the points are always in the same place, but my impression is that they aren’t, although they’re usually near where they were last time; that could easily be wrong.
Do those points have a name? What’s going on there?
Regards,
Ric

May 24, 2011 4:05 pm

Tornado seems to be targeting the NWS center in Norman/Noble.

May 24, 2011 5:02 pm

We might have a right mover developing south of Russel Kansas, on the north end of the squall line. If it does not get undercut by out flow from the other storms in the line, it is building to the east and slightly south, which would put it on a trajectory to pass near Salina Ks. Looks like 68 Dbz returns at the moment.
Unfortunately news is reporting fatalities in Oklahoma.
Larry

May 24, 2011 5:08 pm

Well, we have a NEW line of T-storms developing off the the west along a Cooke-Wise-Parker county line here in the DFW area, and, a new MD:
http://www.spc.noaa.gov/products/md/md0938.html
MESOSCALE DISCUSSION 0938
NWS STORM PREDICTION CENTER NORMAN OK
0643 PM CDT TUE MAY 24 2011
AREAS AFFECTED…CNTRL AND ERN OK THROUGH N-CNTRL TX
CONCERNING…TORNADO WATCH 356…
VALID 242343Z – 250045Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 356 CONTINUES.
THREAT FOR STRONG TORNADOES…VERY LARGE HAIL AND DAMAGING WIND IS EXPECTED TO PERSIST FROM CNTRL THROUGH ERN OK INTO N-CNTRL TX THE NEXT FEW HOURS.
NUMEROUS STORMS INCLUDING A FEW SUPERCELLS CONTINUE FROM N-CNTRL TX THROUGH CNTRL AND E-CNTRL OK. MANY STORMS IN CNTRL OK HAVE BECOME TEMPORARILY LESS ORGANIZED DUE TO DESTRUCTIVE INTERFERENCE ASSOCIATED WITH CELL MERGERS AND OUTFLOW INTERACTIONS. HOWEVER … THE ENVIRONMENT REMAINS SUPPORTIVE OF TORNADOES AND VERY LARGE HAIL WITH LARGE 0-1 KM HODOGRAPHS AND STRONG INSTABILITY … AND SOME STORMS WILL LIKELY REORGANIZE DURING THE EVENING.
FARTHER SOUTH STORMS REMAIN MORE DISCRETE ACROSS N-CNTRL TX AND WILL ALSO CONTINUE TO POSE A THREAT FOR VERY LARGE HAIL AND TORNADOES.
..DIAL.. 05/24/2011

May 24, 2011 6:01 pm

Ric Locke says on May 24, 2011 at 4:05 pm:

The radar also shows something I’ve seen before and don’t understand. Off in west Texas and eastern New Mexico there are points that are centers for cloud formation, with the clouds then streaming off to the east and getting bigger, almost like smoke from a stack. I haven’t checked between times if the points are always in the same place, but my impression is that they aren’t, although they’re usually near where they were last time; that could easily be wrong.

Sounds a lot like smoke Ric, from a forest/range fire; yes, they show up! Saw that numerous times here weeks ago when Texas was burning just to our west …
BTW – Tornado Warning for Tarrant (Ft. Worth) and Dallas counties … tennis-ball sized hail and confirmation of the tornado by spotters 8:01 PM CDT as I type …
.

May 24, 2011 6:47 pm

Finally got electricy back and internet up. Tornadoes passed about 4 miles north. Brothers, sisters, and kids all safe. Sun is going down (8:45 CDT) so it’s going to be extra dangerous for the people to the east if the storms keep up.

_Jim says @ 6:01 pm:
Sounds a lot like smoke Ric, from a forest/range fire; yes, they show up! Saw that numerous times here weeks ago when Texas was burning just to our west …

Do you know where the fires are? I don’t see them on the GOES-13 Wildfire ABBA:
http://cimss.ssec.wisc.edu/goes/burn/wfabba/wfabba_rt66nmex_last.html
OK S.

Tim Clark
May 24, 2011 6:54 pm

Hope you folks in danger take cover. It was a cakewalk today here in Wichita. Nothing like the 7 5/8 ” record breaking hail stone last year. Some six inchers went through my skylights.

SteveSadlov
May 24, 2011 6:58 pm

Two dead near OKC.

SteveSadlov
May 24, 2011 7:01 pm

I can now see the incoming high clouds from the next cold front. The low on this one is progged to come into far Norcal then track into the Great Basin. Then, as these late spring monsters always do, hard left turn and on into the Southern Plains.

SteveSadlov
May 24, 2011 7:10 pm

SXUS76 KMTR 250141 RRA
RERMTR
RECORD EVENT REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
640 PM PST TUE MAY 24 2011
THE FOLLOWING SITE TIED A RECORD LOW TEMPERATURE FOR THIS DATE
LOW PREVIOUS YEAR OF
SITE TEMPERATURE RECORD PREVIOUS RECORD
OAKLAND AIRPORT 47 47 1961
$$
MM
========================
Mind you this is to the SE of the incoming front.

SteveSadlov
May 24, 2011 7:11 pm

SXUS76 KMTR 250141 RRA
RERMTR
RECORD EVENT REPORT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
640 PM PST TUE MAY 24 2011
THE FOLLOWING SITE TIED A RECORD LOW TEMPERATURE FOR THIS DATE
LOW PREVIOUS YEAR OF
SITE TEMPERATURE RECORD PREVIOUS RECORD
OAKLAND AIRPORT 47 47 1961
MM
==================================
This is to the SE of the incoming front.

SteveSadlov
May 24, 2011 7:13 pm

Sorry, was trying to post the actual report but something about characters in it / format is hanging up Word Press.
OAK tied a record low today.
OAKLAND AIRPORT 47 47 1961

May 24, 2011 7:19 pm

OK S. says on May 24, 2011 at 6:47 pm:
Finally got electricy back and internet up. Tornadoes passed about 4 miles north. Brothers, sisters, and kids all safe. Sun is going down (8:45 CDT) so it’s going to be extra dangerous for the people to the east if the storms keep up.
_Jim says @ 6:01 pm:
Sounds a lot like smoke Ric, from a forest/range fire; yes, they show up! Saw that numerous times here weeks ago when Texas was burning just to our west …
Do you know where the fires are? I don’t see them on the GOES-13 Wildfire ABBA:
http://cimss.ssec.wisc.edu/goes/burn/wfabba/wfabba_rt66nmex_last.html
OK S.

Good to hear everything is okay OK.
Here is sample RADAR imagery that shows what Ric (I’m assuming) was seeing and I saw earlier and still seems to be active (could not find anything else in that area of Texas or NM that matched his description):
Static image capture – http://oi56.tinypic.com/mhd2rd.jpg
If you click on this link you can get a 1 hr loop and the ‘stuff’ seems to move south … could be mil aircraft playing with chaff too (the two wide traces just north of the center of the PPI paint). There also appears to be precip a little further to the north.
.

May 24, 2011 7:33 pm

And – lest we think this is all over for _us_, nature takes one last stab … this time with a line of storms kicked off at the boundary of the dryline (which can also be seen on RADAR capture):
http://oi52.tinypic.com/snma9z.jpg
And the 0223z / 09:23 PM CDT surface conditions:
http://oi52.tinypic.com/33mwyew.jpg
.

May 24, 2011 7:53 pm

Incoming via local CH 21/CH11 live news –
Report – Large Tornado on the ground with debris via Skywarn spotters in SE Dallas county, near I-45 and I-20 Hutchins Tx area … 9:50 PM CDT
.

May 24, 2011 8:01 pm

KFWS WSR-88D image capture, Dallas county:
http://oi55.tinypic.com/34i1xnd.jpg
approx. 10:01 PM CDT

May 24, 2011 8:23 pm

RE: _Jim @ 7:19 pm
Thanks. I slowed the GOES-13 page down. It looks like there was a fire at about 10:00 Zulu south of Perryton in the TX panhandle and another about 10:20 Zulu southeast of Guymon in the OK panhandle.
Hope the people in Dallas are okay.
OK S.

John Public
May 24, 2011 8:37 pm

The north end of the storm came through our area, with Tornado sirens blaring, and based on what we were seeing and hearing on the news we expected to see lots of damage from the storm. After getting out, we saw nothing. Based upon past storm warnings and storms (Tornadoes, 100-mph straight winds, heavy hail, and flooding) that have done lots of damage in our area, this storm for our area seems hyped in comparison.

May 24, 2011 8:47 pm

Sorry. I guess I’m tired from all the storms. About 20:15 Zulu on that fire near Guymon, and 00:15 Zulu on the one near Perryton.
OK S.

savethesharks
May 24, 2011 8:49 pm

It is good to be vigilant.
One day….Dallas may be ground zero.
Let’s hope not.
For now those ground zeros are (if that is bad enough) are named Joplin, Tuscaloosa, and so on.
The sheer loss of life and complete destruction from these storms….here in the 21st Century…should give one pause.
This is a bad year for tornadoes. Not outside the realms of natural variability.
But just bad….really BAD.
Here again is a video to remind us all of the power of nature…and our ability to only be in our best fight or flight mode in response.

Chris
Norfolk, VA, USA

savethesharks
May 24, 2011 9:03 pm

John Public says:
May 24, 2011 at 8:37 pm
The north end of the storm came through our area, with Tornado sirens blaring, and based on what we were seeing and hearing on the news we expected to see lots of damage from the storm. After getting out, we saw nothing. Based upon past storm warnings and storms (Tornadoes, 100-mph straight winds, heavy hail, and flooding) that have done lots of damage in our area, this storm for our area seems hyped in comparison.
================
And that is part of the problem: Weighing the costs of warning people for a potential cry wolf scenario…as opposed to the ACTUAL DANGER.
This dilemma is increased exponentially because of the completely EPHEMERAL nature of tornados.
This problem is solvable….but it will take much ingenuity, knowhow, and foresight.
THE FIRST THING THAT NEEDS TO GO: “Junk” computer-generated or doppler-indicated tornado (or even severe thunderstorm) “warnings”.
This is the government, nanny-state BS Big Brother/Sister “protection” at its worst.
When I was a kid a severe thunderstorm….meant hurricane force winds, hail, and power outages.
Now every blip on the radar that “might” be a severe t-storm…IS declared one.
Enough of this milk-toast, nanny-state BS!
Chris
Norfolk, VA, USA

May 24, 2011 9:49 pm

A few areas hard hit, but most of the OKC metro only saw wind and hail. I’m in for some fence repair. We had three long-track tornados, two rated as violent, with fatalities. National news has picked it up. It seems we lost 5 to 7 in OK and KS. There is a missing three-year-old in the NW metro area. There were many homes flattened, with nothing but the slab remaining. http://www.4warn.com/kfor-photos-ok-tornadoes-may-24-20110524,0,7498593.photogallery and http://www.kfor.com/news/local/kfor-tornado-watches-across-oklahoma-20110523,0,166860.story

Dave Springer
May 24, 2011 10:13 pm

Severe weather takes many forms. For instance:
http://www.drought.unl.edu/dm/DM_south.htm
Count your blessings. Uncounted millions of wild animals suffer slow miserable deaths by thirst and starvation in a severe drought. I’d gladly take some severe wet weather right about now. I don’t think we’ve had five inches of rain in as many months. This is when we pray for a major hurricane to hit the coast and drive rain bands far inland.

wayne
May 25, 2011 1:21 am

Here in Oklahoma today one piece of data on tv caught my attention… one channel reported that the cloud sporting the F4 tornado topped above 50,000 ft (15.25 km). That’s the tallest I remember hearing of an anvil-head thunderstorm at this latitude.

kadaka (KD Knoebel)
May 25, 2011 4:40 am

From Dave Springer on May 24, 2011 at 10:13 pm:

Count your blessings. Uncounted millions of wild animals suffer slow miserable deaths by thirst and starvation in a severe drought. (…)

This is obviously something we must immediately get Greenpeace and WWF to work on, maybe even PETA. Drill deep water wells, set up some solar panels, let the generated electricity drive the water pumps, and create watering holes. Broadly speaking, if the skies are sunny and cloudless then conditions are drier and the critters can use the water, if cloudy then cooler and possibly raining so the critters don’t need the water that much. I’m certain those organizations have some funds for global warming research they could channel for this worthwhile project. Maybe they can be convinced it’s all for global warming mitigation, which will look good in their fundraising brochures.
Just don’t use wind turbines as likely only the predators and scavengers will get any real relief, due to the juicy freshly-sliced bird carcasses provided by the turbine blades. As for all the other critters desperately waiting for the wind turbines to provide lots of water so they can survive… WWF and Greenpeace can always just Photoshop out the turbine from their fundraising pics of all the “global warming victims” who had gathered hoping for a sip of water.
=====
Given the great tragedies we’ve seen of tornadoes hitting large cities, it is obvious what must be done.
Trailer homes must be banned from within the borders of all large population centers. It has been proven that tornadoes are drawn to trailer homes due to how frequently they destroy them, just as carbon emissions have been proven to cause global warming. Thus the ban is needed to keep tornadoes from being drawn to such large concentrations of people.
I’m certain federally-funded studies will provide the definitive proof of this effect, as will the subsequent federally-funded studies for several decades to come. Hopefully the researchers will properly include all the hard data generated from their computer models as further definitive proof, as is common in the mature long-established settled science of climatology.
(BTW, who amongst thou, dour of demeanor, wouldst dare to deny a well-needed spot of humor from those who hath been afflicted and affected by these tragic circumstances?)

May 25, 2011 9:42 am

John Public says on May 24, 2011 at 8:37 pm:
The north end of the storm came through our area, with Tornado sirens blaring, and based on what we were seeing and hearing on the news we expected to see lots of damage from the storm. After getting out, we saw nothing. Based upon past storm warnings and storms (Tornadoes, 100-mph straight winds, heavy hail, and flooding) that have done lots of damage in our area, this storm for our area seems hyped in comparison.

John, we escaped any damaging hail, wind and ‘nadoes here as well … but that’s not to say there wasn’t weather just 5 miles away! Listening to the Collin County ARES net on 147.18 MHz there was ‘weather’ experienced by others, notably wind and hail and observed wall clouds. In Dallas and Tarrant counties proper experienced the fuller effects of hail and wind, and perhaps ‘nado action as well.
Now, a segue into a summary of reports from yesterday:
Map, 5-24-2011 Storm reports – http://oi53.tinypic.com/o6a9hz.jpg
Map and location/report data – http://www.spc.noaa.gov/climo/reports/110524_rpts.html
Thankfully, many of us escaped ‘the weather’; we should use the opportunity granted to assist those who were affected, because, surely, our ‘turn in the barrel’ will come about.
.

May 25, 2011 10:07 am

savethesharks says on May 24, 2011 at 9:03 pm:

THE FIRST THING THAT NEEDS TO GO: “Junk” computer-generated or doppler-indicated tornado (or even severe thunderstorm) “warnings”.

It is done so, using automated techniques, since, doing it manually could easily employ half a dozen individuals (analyzing the multiple ‘level plots’ generated by a WSR-88D RADAR, observing for differential velocities, taking into account storm movement, etc) and this would become tedious; this was once the case (doing it manually) using the old WSR-57 and WSR-74 ‘network’ (although not using Doppler; an operator (or several RADAR ops) was actually stationed at a console which had direct control over the WSR-57 RADAR dish and electronics and his job was to analyze, summarize and make observations of RADAR returns as they appeared – there was no storage available aside from the persistence of the phosphor used in the PPI CRT).
Early WSR-88D Tornado Detection Algorithm (TDA):
http://www.nssl.noaa.gov/divisions/warning/swat/tda.php

GOAL: To identify the locally intense circulations associated with tornadoes using Doppler radar data, provide useful guidance to warning operations, and provide at least a 10 minute lead time to tornadoes.
PHILOSOPHY: Identify ALL circulations within Doppler radar data (multiple scans) and distinguish between those which are tornadic and those which are non-tornadic.

This powerpoint (PPT) presentation explains how the WSR-88D (newer software) “Build 10 Tornado Detection Algorithm” works:
wx.db.erau.edu/faculty/mullerb/Wx365/Radar_nws/radarpt3.ppt

The Build 10 Tornadic Detection Algorithm ( TDA ) was developed at the National Severe Storms Laboratory (NSSL) and is designed to detect significant shear regions in the atmosphere. The WSR-88D TDA product in Build 10 displays more operationally pertinent information, and a new graphic symbol.
Performance of the TDA is better than TVS, with a higher probability of detection, some discrimination between tornadic and non-tornadic shear, and a requirement for gate- to-gate shear.

ADVANCED TORNADO DETECTION ALGORITHM USING SUPER-RESOLUTION
AND POLARIMETRIC DATA
ams.confex.com/ams/pdfpapers/155969.pdf

1. INTRODUCTION
The hook shape reflectivity feature has been documented as an indicator of tornadoes [Fujita, 1958], however more than half of the tornadoes have been reported
not associated with apparent hook signature. Tornado vortex signature (TVS) defined as the azimuthal velocity difference at a constant range is a parameter to quantify
the tornado feature based on pulsed Doppler radar observation [Burgess et al., 1975].
The basic idea of the current tornado detection algorithm (TDA) is to search for strong and localized azimuthal shear in the field of mean radial velocities [e.g., Crum and Alberty, 1993; Mitchell et al., 1998]. However, because of the smoothing effect caused by the radar resolution volume, the shear signature can be significantly degraded if the size of tornado is small and/or the tornado is located at far ranges [Brown and Lemon, 1976]. Recently, a neurofuzzy tornado detection algorithm (NFTDA) has been
developed by Wang et al. [2008] within atmospheric radar research center (ARRC) of the university of Oklahoma.
Tornado shear signature and tornado spectral signatures (TSS) are combined in this algorithm, and the performance shows significant improvement.

.

May 25, 2011 11:21 am

They still use human observation ground truth from Skywarn spotters to confirm what the radar is telling them. On many occasions when chasing storms NWS would call us and ask us what we were seeing, then moments after our report the severe warning would go out.
They need the ground truth to sort out some issues that the radar simply cannot tell them. Hail and heavy rain can sometimes be confused, and it really helps to get spotter confirmation that there is in fact a hail signature rather than heavy precipitation.
In addition, the radar cannot see all the way to the ground at a significant distance from the radar due to the curvature of the earth. They may be seeing mid level circulation at the lowest tilt sweep when the storm in 50-100 miles from the radar, and human observation confirming the existence of wall clouds and low level circulation is important to minimize over warning.
One of the problems is the general public has little appreciation of how local storm conditions can be. As a spotter I have dodged 2.5 inch hail on one side of a storm and just a couple miles away another spotter was sitting in bright sunshine and light winds. I have also been less than 1/2 mile from a large tornado and unable to even see it. I have had to drive around for a considerable time to find destructive hail swaths that are only a couple hundred yards wide and a 1/2 mile long. In open country, unless you know what to look for, you can drive right through a tornado path a few hours after it happened and never have a clue it had happened.
During the Last Chance tornado here in Colorado years ago, it put down several small funnels then formed a 1/4 mile wide wedge on the ground that tracked for several miles through farm country. It did remarkably light damage for the size of the storm simply because it failed to hit much. It slam dunked a few cattle killing them, tore up a farmers wind mill and made a grazing hit on the Chris Davis farm, pulled the roof off a barn (leaving a lantern hanging on a post peg untouched) tossing 25′ diameter grain bins a 1/4 of a mile, blowing all the windows out of 3 combines in the field, tried to pickup a household propane tank and spun it around a few times breaking the gas connections, leveled an old steel arch (Quonset hut style) garage, and carried a steel tank 12′ in diameter, and 20 ft long a 1/2 mile, and almost pulled the house off its foundation.
In spite of that long track and its size, it only took down about 3 power poles according to the rural electric crews I talked to that day. If you had not known a tornado had tracked through the area the day before, and did not come within site of the Chris Davis farm you never would have known it had happened except for a couple dead cattle in the fields.
When the wedge first formed, I was less than a mile away on the southwest side and only could see it for a few seconds before it rain wrapped and got swallowed up in the mist and rain.
Larry

SteveSadlov
May 25, 2011 11:50 am

Here’s what’s on tap:
=========================================
ON SUNDAY AN UPPER LOW IS FORECAST TO MOVE SOUTHWARD OVER NORTHERN CALIFORNIA BEFORE HEADING EAST TOWARDS THE GREAT BASIN. THERE ARE DIFFERENCES IN MODEL SOLUTIONS REGARDING THE WESTWARD EXTENT OF THIS LOW`S PATH…THUS WHETHER OR NOT THERE WILL BE ANY SHOWER CHANCES FOR OUR CWA. THE EARLIER RUN OF THE GFS TOOK THIS LOW FARTHER TO THE EAST FOR A COOL BUT DRY SOLUTION FOR OUR AREA… WHEREAS THE ECMWF HAS THE LOW CENTER ITSELF OVER SAN FRANCISCO BY SUNDAY MORNING. THIS WOULD WARRANT PUTTING SOME SHOWER CHANCES INTO OUR FORECAST FOR THAT DAY.
================================================
This one will hit the S. Plains early / mid next week, unless a good blocker builds north from the Gulf.

SteveSadlov
May 25, 2011 11:59 am

Sorry, forgot to mention that today’s front (e.g. the one I described bearing down on us yesterday) is also a good cold pool. Raining here right now (almost unheard of this late in the season).

Robert of Texas
May 25, 2011 7:20 pm

We had a big circulation pass over my house last night. It did some damage to the west (probably a tornado) but by the time it reached my area the circulation was becomming disorganized. Still, once the rain and hail had passed and I knew it was safe, I used this as an excellent opportunity to teach my kids about weather. We counted four small circulating cloud bulges before it had moved on.

rmark
May 25, 2011 8:35 pm

The Hinton – Langston tornado track in Oklahoma happily died down to F1 near Stillwater as it crossed north of our mobile home – the little wind turbine vent on top the storm cellar set up quite the buzz as the tornado passed by.

SteveSadlov
May 26, 2011 9:38 am

See the other thread. Yesterday’s cold pool produced tornadic events here in California.