Alert archive / Louisiana / Mesoscale Discussions in 2012
Mesoscale Discussion 752
The Storm Prediction Center issued this mesoscale discussion at May 7, 2012, 7:21 PM CDT for 9 parishes in Louisiana. It was in force for 54 min.
The area
The outline as issued.
The facts
- Issued
- May 7, 2012, 7:21 PM CDT (00:21 UTC)
- Expired
- May 7, 2012, 8:15 PM CDT
- In force
- 54 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
Counties Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Red River Parish, LA, Webster Parish, LA
The radar
The Shreveport radar (KSHV), 61 km from the middle of the area, began a volume at 00:20 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
Shreveport, LA (KSHV), launched 00:00Z, 0.4 hours before the alert went out and 52 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
- 891 J/kg
- Mixed-layer CIN
- -79 J/kg
- Mixed-layer LCL
- 1717 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 30 m²/s²
- 0-3 km storm-relative helicity
- 72 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
718
ACUS11 KWNS 080022
SWOMCD
SPC MCD 080021
LAZ000-ARZ000-TXZ000-080115-
MESOSCALE DISCUSSION 0752
NWS STORM PREDICTION CENTER NORMAN OK
0721 PM CDT MON MAY 07 2012
AREAS AFFECTED...NRN LA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 080021Z - 080115Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...CLUSTER OF THUNDERSTORMS ACROSS FAR SERN OK AND SWRN AR
WILL CONTINUE TO DEVELOP SSEWD INTO NRN LA. A RELATIVELY BRIEF
TEMPORAL THREAT OF STRONG TO SEVERE STORMS MAY EXIST.
DISCUSSION...A MORE WELL-DEFINED CLUSTER OF THUNDERSTORMS HAS
DEVELOPED ALONG THE MERGING COLD FRONT AND OUTFLOW
BOUNDARY...PROGRESSING SSEWD TOWARDS GREATER INSTABILITY. WEAK
LOW-MID LEVEL FLOW /GENERALLY ABOUT 20 KTS BELOW 500 MB PER 00Z LIT
AND SHV OBSERVED SOUNDINGS/ SHOULD MAINTAIN A LOOSELY ORGANIZED
NATURE OF THE ONGOING CONVECTION. STORMS MAY CONTINUE TO PRODUCE
STRONG TO SEVERE WINDS/HAIL FOR A FEW HOURS BEFORE NOCTURNAL COOLING
GRADUALLY BEGINS TO STABILIZE THE BOUNDARY LAYER.
..HURLBUT/THOMPSON.. 05/08/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...SHV...
LAT...LON 32999410 33079294 32899240 32659231 32279236 31919272
31729315 31719363 32539420 32999410SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 7, 7:39 PM CDT | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more | 4 hr |
| May 7, 9:15 PM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more | 60 min |
Nearby
Mesoscale Discussions in Louisiana, 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.