Alert archive / Oklahoma / Mesoscale Discussions in 2012
Mesoscale Discussion 484
The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2012, 8:54 PM CDT for 20 counties in Oklahoma; 4 counties in Texas. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- Apr 9, 2012, 8:54 PM CDT (01:54 UTC)
- Expired
- Apr 9, 2012, 10:00 PM CDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
All 24 counties
Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Foard County, TX, Hardeman County, TX, Wichita County, TX, Wilbarger County, TX
The radar
The Altus AFB radar (KFDR), 76 km from the middle of the area, began a volume at 01:56 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, 1.9 hours before the alert went out and 173 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
- 900 J/kg
- Mixed-layer CIN
- -41 J/kg
- Mixed-layer LCL
- 726 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 187 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 2.8
The text
As transmitted, in the capitals the NWS used until 2016.
557 ACUS11 KWNS 100154 SWOMCD SPC MCD 100154 OKZ000-TXZ000-100300- MESOSCALE DISCUSSION 0484 NWS STORM PREDICTION CENTER NORMAN OK 0854 PM CDT MON APR 09 2012 AREAS AFFECTED...WRN OK/NWRN TX CONCERNING...TORNADO WATCH 154... VALID 100154Z - 100300Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 154 CONTINUES. OVERALL CHARACTER OF CONVECTION ACROSS THE TORNADO WATCH IS SLOWLY CHANGING AS BOUNDARY LAYER COOLS AND WEAK WARM ADVECTION BEGINS TO DOMINATE VERTICAL PROCESSES. THIS EVOLUTION IS NOTED WELL IN LATEST RADAR DATA WHERE BANDED ELEVATED TSTMS ARE BEGINNING TO DEVELOP ACROSS WCNTRL-CNTRL OK. HAIL WILL BECOME THE PRIMARY SEVERE THREAT AS THUNDERSTORM MODE TRANSITIONS OVER THE NEXT FEW HOURS. FARTHER SOUTH...LEAD SEVERE SUPERCELL IS MOVING SSEWD AT ROUGHLY 20-25KT ACROSS FORD COUNTY. IF CURRENT SPEED/MOVEMENT CONTINUES THIS ACTIVITY WILL EXIT THE SRN MOST COUNTIES OF THE TORNADO WATCH BETWEEN 03-04Z. A NEW WW MAY BE REQUIRED ACROSS PORTIONS OF NWRN TX AND OK. ..DARROW.. 04/10/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OUN...LUB...AMA... LAT...LON 33730001 36909998 36909817 33749827 33730001
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 8:07 PM CDT | Mesoscale Discussion | SPC | Craig, Nowata, Osage, Rogers, Washington | 83 min |
| Apr 10, 12:52 AM CDT | Mesoscale Discussion | SPC | Greer, Harmon, Jackson, Tillman | 23 min |
| Apr 10, 1:56 PM CDT | Mesoscale Discussion | SPC | Choctaw, McCurtain | 64 min |
| Apr 10, 3:35 PM CDT | Mesoscale Discussion | SPC | Beaver, Cimarron, Ellis, Roger Mills, Texas | 115 min |
| Apr 9, 7:33 PM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Cochran, Crane, Crosby, Dawson and 25 more | 57 min |
| Apr 10, 12:25 AM CDT | Mesoscale Discussion | SPC | Brewster, Pecos, Presidio, Terrell | 35 min |
Nearby
Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012
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.