Alert archive / Louisiana / Mesoscale Discussions in 2012
Mesoscale Discussion 2167
The Storm Prediction Center issued this mesoscale discussion at Dec 16, 2012, 9:49 PM CST for 18 parishes in Louisiana. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Dec 16, 2012, 9:49 PM CST (03:49 UTC)
- Expired
- Dec 16, 2012, 10:45 PM CST
- In force
- 56 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA
The radar
The Lake Charles radar (KLCH), 97 km from the middle of the area, began a volume at 03:50 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
Lake Charles Mun, LA (KLCH), launched 00:00Z, 3.8 hours before the alert went out and 95 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
- 745 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- -43 m²/s²
- 0-3 km storm-relative helicity
- 18 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
231
ACUS11 KWNS 170349
SWOMCD
SPC MCD 170349
LAZ000-170445-
MESOSCALE DISCUSSION 2167
NWS STORM PREDICTION CENTER NORMAN OK
0949 PM CST SUN DEC 16 2012
AREAS AFFECTED...SRN LA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 170349Z - 170445Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...INCREASING THUNDERSTORM ACTIVITY WILL TRACK E/NEWD ACROSS
SRN LA TONIGHT. SEVERE THREAT IS EXPECTED TO REMAIN LOW AND A WATCH
IS NOT ANTICIPATED. HOWEVER...AN ISOLATED STRONG WIND GUST MAY BE
POSSIBLE WITH THE STRONGEST STORMS.
DISCUSSION...THUNDERSTORMS WERE INTENSIFYING ACROSS PORTIONS OF SRN
LA THIS EVENING. AN OUTFLOW BOUNDARY FROM AFTERNOON CONVECTION
EXTENDED S/SW FROM THE FL PANHANDLE INTO THE GULF WATERS SOUTH OF LA
PER 03Z SFC OBS. BEHIND THE BOUNDARY...DEWPOINTS WERE IN THE LOW 60S
WITH DEWPOINTS NEAR 70 TO THE EAST OF THE BOUNDARY. MOIST ADVECTION
OVER THIS BOUNDARY IS LIKELY RESPONSIBLE FOR THE INCREASE IN
ELEVATED THUNDERSTORM ACTIVITY. 00Z RAOBS FROM LCH AND LIX INDICATE
POOR LOW AND MID LEVEL LAPSE RATES WITH ONLY MARGINAL ELEVATED
INSTABILITY. THEREFORE...DESPITE ADEQUATE SHEAR FOR SEMI-ORGANIZED
STRUCTURES THE SEVERE THREAT IS EXPECTED TO REMAIN LOW AND A WATCH
IS NOT ANTICIPATED.
..LEITMAN/MEAD.. 12/17/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LIX...LCH...
LAT...LON 28899368 28969398 29229409 29969335 30339276 30679192
30859105 30699069 30259062 29979079 29639115 29439182
28899368Nearby
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.