Alert archive / Alabama / Mesoscale Discussions in 2013

Mesoscale Discussion 283

March 18, 201312 counties in Alabama; Holmes County, Florida

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2013, 11:37 PM CDT for 12 counties in Alabama; Holmes County, Florida. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Mar 18, 2013, 11:37 PM CDT (04:37 UTC)
Expired
Mar 19, 2013, 1:00 AM CDT
In force
83 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Butler County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Monroe County, AL, Pike County, AL, Holmes County, FL

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 4.6 hours before the alert went out and 210 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, Tallahassee Rgnl, FL at 00:00Z on 2013-03-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 488 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, Tallahassee Rgnl, FL at 00:00Z on 2013-03-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 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
488 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
744 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
204 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 18, 7:03 PM CDTMesoscale DiscussionSPCCoffee, Covington, Dale, Geneva, Henry, Houston117 min
Mar 19, 2:23 AM CDTMesoscale DiscussionSPCAlachua, Baker, Bay, Bradford, Calhoun, Columbia and 16 more97 min

Nearby

Mesoscale Discussions in Alabama, 2013Mesoscale Discussions in Florida, 2013Every mesoscale discussion in 2013

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.