Alert archive / Oklahoma / Mesoscale Discussions in 2015
Mesoscale Discussion 521
The Storm Prediction Center issued this mesoscale discussion at May 6, 2015, 5:25 PM CDT for 33 counties in Oklahoma; 19 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 6, 2015, 5:25 PM CDT (22:25 UTC)
- Expired
- May 6, 2015, 7:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 52 counties
Alfalfa County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Jackson County, OK, Jefferson County, OK, Kingfisher County, OK, Kiowa County, OK, Logan County, OK, Love County, OK, Major County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Pottawatomie County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Foard County, TX, Hardeman County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Stephens County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX
The radar
The Altus AFB radar (KFDR), 40 km from the middle of the area, began a volume at 22:28 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Norman, OK (KOUN), launched 12:00Z, 10.4 hours before the alert went out and 134 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1226 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 562 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 219 m²/s²
- 0-3 km storm-relative helicity
- 308 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 9.1
The text
As transmitted, in the capitals the NWS used until 2016.
737
ACUS11 KWNS 062225
SWOMCD
SPC MCD 062225
OKZ000-TXZ000-KSZ000-070030-
MESOSCALE DISCUSSION 0521
NWS STORM PREDICTION CENTER NORMAN OK
0525 PM CDT WED MAY 06 2015
AREAS AFFECTED...OK/WRN N TX
CONCERNING...TORNADO WATCH 133...
VALID 062225Z - 070030Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 133 CONTINUES.
SUMMARY...SEVERE/TORNADO RISK PERSISTS ACROSS THE WW AREA...WHERE
SEVERAL SUPERCELLS ARE ONGOING ATTM.
DISCUSSION...SEVERAL SUPERCELLS ARE ONGOING ATTM FROM CENTRAL KS SWD
ACROSS WRN OK AND INTO WRN N TX...WITH STORMS INITIATING NEAR AND E
OF A WEAK DRYLINE EXTENDING FROM W CENTRAL KS ACROSS WRN OK INTO THE
TX SOUTH PLAINS.
ENVIRONMENT AHEAD OF THE DRYLINE HAS BECOME MODERATELY UNSTABLE
/MIXED-LAYER CAPE 1500 TO 2500 J/KG/...AS HEATING OF AN INCREASINGLY
MOIST /MID 60S TO NEAR 70 DEWPOINTS/ BOUNDARY LAYER HAS OCCURRED
THIS AFTERNOON. THIS CONTINUES TO FUEL AN INCREASE IN BOTH STORM
COVERAGE AND INTENSITY -- AIDED BY VERY FAVORABLY VEERING FLOW WITH
HEIGHT AS WINDS SHIFT FROM SSELY AT THE SURFACE TO WSWLY AT MID
LEVELS.
WHILE SEVERAL SEVERE STORMS ARE ONGOING...ONE LARGE STORM W OF OUN
/NORMAN OK/ HAS BECOME PARTICULARLY INTENSE -- WITH MULTIPLE
TORNADOES REPORTED WITH THIS STORM RECENTLY. THE STORM HAS BEEN
MOVING SLOWLY WITH CONTINUED UPDRAFT REGENERATION ON ITS WRN
FLANK...BUT ATTM IT APPEARS THAT THE STORM SHOULD AFFECT THE SRN OKC
METRO AREA INCLUDING THE MOORE/NORMAN VICINITY IN THE NEXT HOUR OR
SO.
..GOSS.. 05/06/2015
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ICT...FWD...OUN...SJT...
LAT...LON 32579994 33549991 36739941 37089782 36189697 34839695
32509768 32579994SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 6, 1:03 PM CDT | Mesoscale Discussion | SPC | Comanche, Cotton, Greer, Harmon, Jackson, Jefferson and 3 more | 117 min |
| May 6, 1:09 PM CDT | Mesoscale Discussion | SPC | Woods | 3 hr |
| May 6, 1:23 PM CDT | Tornado Watch | SPC | Alfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 29 more | 8 hr |
| May 6, 3:27 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 28 more | 2 hr |
| May 6, 6:34 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 34 more | 86 min |
| May 5, 7:41 PM CDT | Mesoscale Discussion | SPC | Borden, Briscoe, Childress, Cottle, Crosby, Dickens and 15 more | 2 hr |
| May 5, 8:07 PM CDT | Tornado Watch | SPC | Coke, Cottle, Crosby, Dickens, Fisher, Foard and 14 more | 4 hr |
| May 5, 9:56 PM CDT | Mesoscale Discussion | SPC | Borden, Callahan, Coke, Cottle, Crosby, Dickens and 23 more | 94 min |
| May 6, 1:46 PM CDT | Mesoscale Discussion | SPC | Brown, Callahan, Coke, Coleman, Concho, Crockett and 22 more | 119 min |
| May 6, 3:00 PM CDT | Tornado Watch | SPC | Brown, Coke, Coleman, Concho, Crockett, Fisher and 12 more | 7 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2015Mesoscale Discussions in Texas, 2015Every mesoscale discussion in 2015
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.