Alert archive / Arkansas / Mesoscale Discussions in 2009

Mesoscale Discussion 302

March 27, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Mar 27, 2009, 5:53 PM CDT for 4 states. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Mar 27, 2009, 5:53 PM CDT (22:53 UTC)
Expired
Mar 27, 2009, 7:30 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
All 46 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Polk County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Claiborne Parish, LA, East Carroll Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Madison County, MS, Sharkey County, MS, Warren County, MS, Washington County, MS, Yazoo County, MS, Bowie County, TX, Cass County, TX

The radar

The Shreveport radar (KSHV), 167 km from the middle of the area, began a volume at 22:57 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 12:00Z, 10.9 hours before the alert went out and 158 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, Shreveport, LA at 12:00Z on 2009-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 142 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, Shreveport, LA at 12:00Z on 2009-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 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
142 J/kg
Mixed-layer CIN
-191 J/kg
Mixed-layer LCL
516 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

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 26, 9:28 PM CDTMesoscale DiscussionSPCHoward, Montgomery, Polk, Scott, Sevier62 min
Mar 27, 12:33 PM CDTMesoscale DiscussionSPCHempstead, Howard, Lafayette, Little River, Miller, Sevier57 min
Mar 27, 12:58 PM CDTTornado WatchSPCHoward, Little River, Miller, Sevier7 hr
Mar 27, 3:34 PM CDTMesoscale DiscussionSPCHoward, Little River, Miller, Sevier56 min
Mar 27, 6:35 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 27 more7 hr
Mar 26, 9:13 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 16 more92 min
Mar 26, 11:53 PM CDTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 7 more97 min
Mar 27, 12:48 AM CDTTornado WatchSPCAscension, Assumption, Iberville, Jefferson, Lafourche, Livingston and 10 more7 hr
Mar 27, 2:23 AM CDTMesoscale DiscussionSPCAssumption, Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard and 3 more67 min
Mar 27, 4:37 AM CDTMesoscale DiscussionSPCJefferson, Lafourche, Plaquemines, Saint Bernard53 min
Mar 27, 6:35 AM CDTMesoscale DiscussionSPCJefferson, Plaquemines55 min
Mar 27, 2:34 PM CDTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Evangeline, Rapides, Saint Landry and 1 more56 min
Mar 27, 2:54 PM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, East Baton Rouge and 14 more6 hr
Mar 27, 4:16 PM CDTTornado WatchSPCCaldwell, Catahoula, Concordia, Franklin, Grant, LaSalle and 1 more4 hr
Mar 27, 4:49 PM CDTTornado WatchSPCCameron3 hr
Mar 27, 6:18 PM CDTMesoscale DiscussionSPCLivingston, Saint Helena, Saint Tammany, Tangipahoa, Washington57 min
Mar 26, 7:32 PM CDTSevere Thunderstorm WatchSPCCooke, Denton, Fannin, Grayson, Jack, Montague and 1 more4 hr
Mar 26, 11:34 PM CDTMesoscale DiscussionSPCDallam, Hartley, Moore, Oldham, Sherman4 hr
Mar 27, 2:55 AM CDTMesoscale DiscussionSPCArmstrong, Carson, Dallam, Deaf Smith, Hansford, Hartley and 9 more4 hr
Mar 27, 8:04 AM CDTMesoscale DiscussionSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Ochiltree and 2 more4 hr
Mar 27, 10:24 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Brazoria and 43 more96 min
Mar 27, 11:48 AM CDTSevere Thunderstorm WatchSPCAustin, Brazos, Burleson, Chambers, Grimes, Hardin and 16 more5 hr
Mar 27, 12:30 PM CDTMesoscale DiscussionSPCCarson, Childress, Collingsworth, Donley, Gray, Hansford and 8 more6 hr
Mar 27, 3:43 PM CDTMesoscale DiscussionSPCChambers, Hardin, Harris, Jasper, Jefferson, Liberty and 6 more62 min

Nearby

Mesoscale Discussions in Arkansas, 2009Mesoscale Discussions in Louisiana, 2009Mesoscale Discussions in Mississippi, 2009Every mesoscale discussion in 2009

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.