Alert archive / Kentucky / Mesoscale Discussions in 2009

Mesoscale Discussion 1773

August 4, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2009, 2:36 PM CDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Aug 4, 2009, 2:36 PM CDT (19:36 UTC)
Expired
Aug 4, 2009, 4:00 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
All 106 counties

Alexander County, IL, Gallatin County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, Williamson County, IL, Adair County, KY, Allen County, KY, Ballard County, KY, Barren County, KY, Boyle County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Casey County, KY, Christian County, KY, Clinton County, KY, Crittenden County, KY, Cumberland County, KY, Daviess County, KY, Edmonson County, KY, Fulton County, KY, Graves County, KY, Grayson County, KY, Green County, KY, Hardin County, KY, Hart County, KY, Hickman County, KY, Hopkins County, KY, Larue County, KY, Laurel County, KY, Lincoln County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marion County, KY, Marshall County, KY, McCracken County, KY, McCreary County, KY, McLean County, KY, Metcalfe County, KY, Monroe County, KY, Muhlenberg County, KY, Ohio County, KY, Pulaski County, KY, Russell County, KY, Simpson County, KY, Taylor County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Wayne County, KY, Webster County, KY, Whitley County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dent County, MO, Douglas County, MO, Greene County, MO, Howell County, MO, Iron County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Perry County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO, Campbell County, TN, Cheatham County, TN, Clay County, TN, Cumberland County, TN, Fentress County, TN, Jackson County, TN, Macon County, TN, Montgomery County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Scott County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Wilson County, TN

The radar

The Paducah radar (KPAH), 73 km from the middle of the area, began a volume at 19:39 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

Nashville Metro, TN (KBNA), launched 12:00Z, 7.6 hours before the alert went out and 166 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, Nashville Metro, TN at 12:00Z on 2009-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3443 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, Nashville Metro, TN at 12:00Z on 2009-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 square meters per square second.1939Sfc1 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
3443 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
680 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

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
Aug 4, 4:06 AM CDTSevere Thunderstorm WatchSPCAdams, Brown, Calhoun, Greene, Hancock, Jersey and 2 more5 hr
Aug 4, 7:11 AM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 8 more94 min
Aug 4, 7:39 AM CDTSevere Thunderstorm WatchSPCBond, Cass, Champaign, Christian, Clark, Clay and 37 more4 hr
Aug 4, 3:09 PM CDTSevere Thunderstorm WatchSPCAlexander, Franklin, Gallatin, Hardin, Jackson, Johnson and 8 more7 hr
Aug 4, 6:21 PM CDTMesoscale DiscussionSPCAlexander, Johnson, Massac, Pope, Pulaski, Union114 min
Aug 4, 4:37 AM CDTMesoscale DiscussionSPCBoone53 min
Aug 4, 8:41 AM CDTSevere Thunderstorm WatchSPCCarroll, Gallatin, Henry, Jefferson, Oldham, Owen and 1 more6 hr
Aug 4, 8:47 AM CDTMesoscale DiscussionSPCBoone, Carroll, Gallatin, Grant, Henry, Jefferson and 5 more58 min
Aug 4, 11:41 AM CDTMesoscale DiscussionSPCAdair, Anderson, Barren, Boyle, Breckinridge, Bullitt and 43 more94 min
Aug 4, 12:21 PM CDTSevere Thunderstorm WatchSPCAdair, Allen, Anderson, Barren, Bell, Bourbon and 58 more7 hr
Aug 4, 3:29 PM CDTSevere Thunderstorm WatchSPCHarlan, Knott, Leslie, Letcher, Perry6 hr
Aug 4, 5:45 PM CDTMesoscale DiscussionSPCAllen, Barren, Breckinridge, Butler, Daviess, Edmonson and 9 more90 min
Aug 4, 1:10 AM CDTSevere Thunderstorm WatchSPCAndrew, Atchison, Holt, Nodaway6 hr
Aug 4, 2:11 AM CDTMesoscale DiscussionSPCAdair, Caldwell, Chariton, Daviess, DeKalb, Gentry and 13 more2 hr
Aug 4, 5:49 AM CDTMesoscale DiscussionSPCAtchison, Holt56 min
Aug 4, 6:34 PM CDTSevere Thunderstorm WatchSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 35 more4 hr

Nearby

Mesoscale Discussions in Kentucky, 2009Mesoscale Discussions in Missouri, 2009Mesoscale Discussions in Tennessee, 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.