Alert archive / Mississippi / Mesoscale Discussions in 2009

Mesoscale Discussion 2127

October 22, 2009Chicot County, Desha County, Phillips County, Arkansas; 11 parishes in Louisiana; 30 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Oct 22, 2009, 6:26 PM CDT for Chicot County, Desha County, Phillips County, Arkansas; 11 parishes in Louisiana; 30 counties in Mississippi. It was in force for 34 min.

The area

The outline as issued.

The facts

Issued
Oct 22, 2009, 6:26 PM CDT (23:26 UTC)
Expired
Oct 22, 2009, 7:00 PM CDT
In force
34 min
Issued by
the Storm Prediction Center
All 44 counties

Chicot County, AR, Desha County, AR, Phillips County, AR, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Madison Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Adams County, MS, Amite County, MS, Bolivar County, MS, Carroll County, MS, Claiborne County, MS, Coahoma County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lawrence County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Pike County, MS, Quitman County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Sunflower County, MS, Tallahatchie County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 86 km from the middle of the area, began a volume at 23:27 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

Jackson, MS (KJAN), launched 12:00Z, 11.4 hours before the alert went out and 80 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, Jackson, MS at 12:00Z on 2009-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Jackson, MS at 12:00Z on 2009-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 194 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
843 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
194 m²/s²
0-3 km storm-relative helicity
250 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Oct 22, 5:35 AM CDTMesoscale DiscussionSPCBeauregard, Calcasieu, De Soto, Sabine, Vernon85 min
Oct 22, 5:55 AM CDTTornado WatchSPCAcadia, Allen, Beauregard, Calcasieu, Caldwell, Cameron and 12 more6 hr
Oct 22, 7:48 AM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 19 more117 min
Oct 22, 10:14 AM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 10 more91 min
Oct 22, 11:27 AM CDTMesoscale DiscussionSPCAscension, Assumption, Avoyelles, Caldwell, Catahoula, Concordia and 26 more93 min
Oct 22, 11:58 AM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 40 more7 hr
Oct 22, 3:36 PM CDTMesoscale DiscussionSPCAscension, Assumption, Catahoula, Concordia, East Baton Rouge, East Carroll and 14 more114 min
Oct 22, 4:35 PM CDTTornado WatchSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more4 hr
Oct 22, 6:55 PM CDTTornado WatchSPCAttala, Bolivar, Carroll, Copiah, Covington, Forrest and 22 more3 hr

Nearby

Mesoscale Discussions in Mississippi, 2009Mesoscale Discussions in Louisiana, 2009Mesoscale Discussions in Arkansas, 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.