Alert archive / Oklahoma / Mesoscale Discussions in 2012
Mesoscale Discussion 841
The Storm Prediction Center issued this mesoscale discussion at May 19, 2012, 6:30 PM CDT for 13 counties in Oklahoma. It was in force for 30 min.
The area
The outline as issued.
The facts
- Issued
- May 19, 2012, 6:30 PM CDT (23:30 UTC)
- Expired
- May 19, 2012, 7:00 PM CDT
- In force
- 30 min
- Issued by
- the Storm Prediction Center
Counties Alfalfa County, OK, Blaine County, OK, Canadian County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grant County, OK, Kay County, OK, Kingfisher County, OK, Major County, OK, Roger Mills County, OK, Woods County, OK, Woodward County, OK
The radar
The Vance AFB radar (KVNX), 102 km from the middle of the area, began a volume at 23:31 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
Lamont, OK (KLMN), launched 12:00Z, 11.5 hours before the alert went out and 133 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
- 450 J/kg
- Mixed-layer CIN
- -768 J/kg
- Mixed-layer LCL
- 1247 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 330 m²/s²
- 0-3 km storm-relative helicity
- 445 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
723 ACUS11 KWNS 192331 SWOMCD SPC MCD 192330 OKZ000-TXZ000-200000- MESOSCALE DISCUSSION 0841 NWS STORM PREDICTION CENTER NORMAN OK 0630 PM CDT SAT MAY 19 2012 AREAS AFFECTED...NWRN OK CONCERNING...SEVERE THUNDERSTORM WATCH 282... VALID 192330Z - 200000Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 282 CONTINUES. SUMMARY...PRIMARY THREAT FOR DMGG WINDS AND LARGE HAIL WILL CONTINUE ACROSS WW 282 THROUGH AT LEAST THE NEXT 1-2 HRS. CLUSTER OF STORMS WILL EVENTUALLY SHIFT E-SEWD WITH A GRADUALLY DECREASING DMGG WIND/HAIL THREAT EXPECTED BEYOND SUNSET. DISCUSSION...RADAR TRENDS INDICATE RAPID DEVELOPMENT OF CONVECTION OCCURRING WITHIN A WELL-MIXED BOUNDARY LAYER ALONG A SEWD MOVING COLD FRONT...ANALYZED FROM 40 WNW CSM TO 10 NE AVK AS OF 23Z. THE STRONGEST STORMS WILL CONTINUE TO REMAIN CAPABLE OF PRODUCING DMGG WINDS AND LARGE HAIL...AND A PERHAPS A BRIEF/WEAK TORNADO...THROUGH AT LEAST THE NEXT 1-2 HRS...WITH THE ENVIRONMENT REMAINING SUFFICIENTLY UNSTABLE THROUGH SUNSET. LATEST CONVECTION-ALLOWING MODEL GUIDANCE INDICATES A TSTM CLUSTER WILL PROPAGATE E-SEWD LATER THIS EVENING. OBJECTIVE ANALYSIS FIELDS AND SOUNDINGS FROM EARLIER TODAY SUGGEST A STRONGER CAPPING INVERSION IS IN PLACE WITH EWD EXTENT...WHICH ALONG WITH DIURNAL COOLING EFFECTS...SHOULD LEAD TO A REDUCED DMGG WIND THREAT WITH TIME. A THREAT FOR HAIL COULD PERSIST GIVEN THE PRESENCE OF STEEP MIDLEVEL LAPSE RATES AND MUCAPE VALUES EXCEEDING 1000 J/KG. ..ROGERS.. 05/19/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OUN...AMA... LAT...LON 35339811 35330022 35700005 36999880 36999694 35339811
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 2:36 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Major, Woods, Woodward | 84 min |
| May 19, 3:52 PM CDT | Severe Thunderstorm Watch | SPC | Alfalfa, Beckham, Blaine, Caddo, Canadian, Custer and 12 more | 6 hr |
Nearby
Mesoscale Discussions in Oklahoma, 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.