Alert archive / Louisiana / Mesoscale Discussions in 2012

Mesoscale Discussion 70

January 25, 201219 parishes in Louisiana

The Storm Prediction Center issued this mesoscale discussion at Jan 25, 2012, 1:41 PM CST for 19 parishes in Louisiana. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Jan 25, 2012, 1:41 PM CST (19:41 UTC)
Expired
Jan 25, 2012, 3:15 PM CST
In force
94 min
Issued by
the Storm Prediction Center

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, West Baton Rouge Parish, LA

The radar

The Lake Charles radar (KLCH), 90 km from the middle of the area, began a volume at 19:41 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.7 hours before the alert went out and 89 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.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 12:00Z on 2012-01-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 28 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2012-01-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 241 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
28 J/kg
Mixed-layer CIN
-201 J/kg
Mixed-layer LCL
576 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
241 m²/s²
0-3 km storm-relative helicity
341 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

202 
ACUS11 KWNS 251942
SWOMCD
SPC MCD 251941
LAZ000-MSZ000-TXZ000-252115-

MESOSCALE DISCUSSION 0070
NWS STORM PREDICTION CENTER NORMAN OK
0141 PM CST WED JAN 25 2012

AREAS AFFECTED...LA INTO WRN MS

CONCERNING...TORNADO WATCH 15...

VALID 251941Z - 252115Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 15 CONTINUES.

THE TORNADO AND SEVERE WIND THREAT PERSISTS ACROSS TORNADO WATCH
15...AND A REPLACEMENT WATCH IS LIKELY.

LINE OF CONVECTION WITH EMBEDDED LEWPS AND MESOCYCLONES IS NEAR THE
SABINE RIVER...ORIENTED NNE TO SSW. SURFACE OBSERVATIONS INDICATE
THAT THE WARM FRONT HAS SHIFTED NWD TO THE LA/AR BORDER AND ACROSS
NWRN MS...WITH TEMPERATURES NOW IN THE MID 70S F. THUS...THERE MAY
BE SOME INCREASE IN WIND POTENTIAL WITH THE APPROACHING BOWS NOW
OVER NRN LA.

TO THE S...POCKETS OF HEATING HAVE YIELDED SCATTERED SHOWERS AHEAD
OF THE MAIN LINE...AND NEAR A SECONDARY WARM/MOIST FRONT DELINEATING
LOW 60S DEWPOINTS TO THE N AND UPPER 60S TO THE S. WITH THE INFLUX
OF BETTER MOISTURE...AND VERY FAVORABLE WIND PROFILES AS SEEN ON 18Z
LCH SOUNDING...THE THREAT FOR TORNADOES REMAINS...ESPECIALLY OVER
CNTRL AND SRN LA.

..JEWELL.. 01/25/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...JAN...LIX...LCH...SHV...

LAT...LON   29409136 29519422 30069379 31169355 31319334 31379262
            31119175 30729124 30299117 29709111 29409136

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 25, 7:56 AM CSTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 24 more7 hr
Jan 25, 11:24 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 25 more2 hr
Jan 25, 2:08 PM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 41 more7 hr
Jan 25, 4:49 PM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Avoyelles, Cameron, Catahoula and 24 more86 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.