Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 70

January 18, 2017Beauregard Parish, Calcasieu Parish, Louisiana; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jan 18, 2017, 2:41 PM CST for Beauregard Parish, Calcasieu Parish, Louisiana; 4 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jan 18, 2017, 2:41 PM CST (20:41 UTC)
Expired
Jan 18, 2017, 5:15 PM CST
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
5%

Counties Beauregard Parish, LA, Calcasieu Parish, LA, Jasper County, TX, Jefferson County, TX, Newton County, TX, Orange County, TX

The radar

The Lake Charles radar (KLCH), 65 km from the middle of the area, began a volume at 20:43 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 12:00Z, 8.7 hours before the alert went out and 67 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 2017-01-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 729 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 2017-01-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 square meters per square second.19395878Sfc1 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
729 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
512 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 17, 7:08 PM CSTMesoscale DiscussionSPCAransas, Calhoun, Duval, Jackson, Jim Wells, Kleberg and 5 more2 hr
Jan 18, 1:49 AM CSTMesoscale DiscussionSPCAustin, Colorado, Fort Bend, Harris, Liberty, Montgomery and 3 more86 min

Nearby

Mesoscale Discussions in Texas, 2017Mesoscale Discussions in Louisiana, 2017Every mesoscale discussion in 2017

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.