Alert archive / Oklahoma / Mesoscale Discussions in 2011
Mesoscale Discussion 604
The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2011, 7:08 PM CDT for 34 counties in Oklahoma; 19 counties in Texas. It was in force for 97 min.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2011, 7:08 PM CDT (00:08 UTC)
- Expired
- Apr 26, 2011, 8:45 PM CDT
- In force
- 97 min
- Issued by
- the Storm Prediction Center
All 53 counties
Beaver County, OK, Beckham County, OK, Blaine County, OK, Bryan County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garvin County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Jefferson County, OK, Johnston County, OK, Kiowa County, OK, Love County, OK, Major County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Roger Mills County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Woodward County, OK, Archer County, TX, Baylor County, TX, Childress County, TX, Clay County, TX, Collingsworth County, TX, Foard County, TX, Gray County, TX, Hansford County, TX, Hardeman County, TX, Hemphill County, TX, Hutchinson County, TX, Knox County, TX, Lipscomb County, TX, Montague County, TX, Ochiltree County, TX, Roberts County, TX, Wheeler County, TX, Wichita County, TX, Wilbarger County, TX
The radar
The Altus AFB radar (KFDR), 70 km from the middle of the area, began a volume at 00:10 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 nearest sounding before it
Norman, OK (KOUN), launched 00:00Z, 0.1 hours before the alert went out and 145 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1149 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 124 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
257
ACUS11 KWNS 270008
SWOMCD
SPC MCD 270008
OKZ000-TXZ000-270145-
MESOSCALE DISCUSSION 0604
NWS STORM PREDICTION CENTER NORMAN OK
0708 PM CDT TUE APR 26 2011
AREAS AFFECTED...PORTIONS SWRN/S-CENTRAL/NWRN OK...NW TX...ERN
PANHANDLES OF TX/OK.
CONCERNING...SEVERE THUNDERSTORM WATCH 218...
VALID 270008Z - 270145Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 218
CONTINUES.
SVR POTENTIAL ACROSS WW AREA...HOWEVER...MAY DIMINISH THROUGH
REMAINDER EVENING WITH LOSS OF DIABATIC SFC HEATING AND RESULTANT
CONTRIBUTIONS TO LOW-LEVEL LAPSE RATES. POTENTIAL FOR ISOLATED LRG
HAIL WILL CONTINUE FOR ANOTHER COUPLE HOURS WITH ACTIVITY FARTHER NW
ACROSS PORTIONS TX/OK PANHANDLES...MOVING INTO NWRN OK.
SFC MESOANALYSIS SHOWS COLD FRONT WELL S OF WW AREA -- FROM SRN
PORTIONS DFW METROPLEX SWWD OVER NRN HILL COUNTRY THEN NWWD PAST
ABI...BECOMING WARM FRONT NWWD INTO SFC LOW LOCATED OVER EXTREME
N-CENTRAL TX PANHANDLE. WARM FRONT SHOULD LIFT NEWD INTO SWRN OK
THROUGH 06Z. DEEP-LAYER ASCENT IN FORM OF BOTH DCVA AND ELEVATED
WAA MAY REMAIN RELATIVELY MAXIMIZED JUST E AND NE OF THAT
LOW...WHICH IS FCST TO MOVE SEWD ALONG WARM FRONT. ERN PANHANDLES
ARE CHARACTERIZED BY 250-700 J/KG MLCAPE ROOTED NEAR 700 MB BUT WEAK
EFFECTIVE SHEAR...BASED ON MODIFIED RUC SOUNDINGS. MUCAPE WILL
INCREASE WITH SEWD EXTENT ACROSS WRN OK AND NW TX...BUT SO WILL
CINH...MAKING ADDITIONAL POTENTIAL VERY CONDITIONAL ACROSS CURRENT
WW AREA. DEPENDING ON INTERVENING CONVECTIVE TRENDS...WW MAY BE
ALLOWED TO EXPIRE AS SCHEDULED AT 03Z...AND/OR AT LEAST PARTIALLY
CLEARED BEFORE THEN.
..EDWARDS.. 04/27/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FWD...OUN...LUB...AMA...
LAT...LON 33489793 33519989 35270057 35810171 36410187 36880099
36809909 35809787 34759627 33969622 33789725 33489793SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 8:53 PM CDT | Mesoscale Discussion | SPC | McCurtain | 97 min |
| Apr 27, 8:40 AM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Haskell, LeFlore, Sequoyah | 65 min |
| Apr 26, 9:42 PM CDT | Tornado Watch | SPC | Anderson, Angelina, Bell, Brazos, Burleson, Cherokee and 29 more | 7 hr |
| Apr 26, 11:33 PM CDT | Mesoscale Discussion | SPC | Angelina, Brazos, Burleson, Falls, Grimes, Houston and 18 more | 117 min |
| Apr 27, 3:29 AM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Delta and 22 more | 2 hr |
| Apr 27, 4:53 AM CDT | Severe Thunderstorm Watch | SPC | Bowie, Camp, Cass, Cherokee, Franklin, Gregg and 9 more | 5 hr |
| Apr 27, 9:48 AM CDT | Mesoscale Discussion | SPC | Harrison, Marion, Panola | 27 min |
Nearby
Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011
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.