Alert archive / Mississippi / Heat Advisories in 2012

Heat Advisory 4, NWS Memphis, TN

July 21, 201222 counties in Mississippi; 20 counties in Tennessee; 12 counties in Arkansas

NWS Memphis, TN issued this heat advisory at Jul 21, 2012, 3:04 PM CDT for 22 counties in Mississippi; 20 counties in Tennessee; 12 counties in Arkansas. It took effect at Jul 24, 2012, 10:00 AM CDT. It was in force for 57 hr.

The area

The counties it named.

The facts

Issued: Jul 21, 2012, 3:04 PM CDT (20:04 UTC)
In effect from: Jul 24, 2012, 10:00 AM CDT
Expired: Jul 26, 2012, 7:00 PM CDT
In force: 57 hr
Issued by: NWS Memphis, TN

All 54 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lawrence County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, Randolph County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 41 km from the middle of the area, began a volume at 20:03 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

Little Rock, AR (KLZK), launched 12:00Z, 8.1 hours before the alert went out and 55 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 947 J/kg
Mixed-layer CIN: -161 J/kg
Mixed-layer LCL: 1082 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: -27 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.5

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Memphis, TN wrote its last area forecast discussion before this heat advisory went out at Jul 21, 12:53 PM CDT, 2 hours 11 minutes earlier.

Area forecast discussion, Jul 21, 12:53 PM CDT, 2 hours 11 minutes before

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Hazardous weather outlook, Jul 21, 9:33 AM CDT, 5 hours 31 minutes before

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In the hours before

Special weather statement, Jul 21, 1:55 PM CDT, 1 hour 9 minutes before

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Special weather statement, Jul 21, 2:57 PM CDT, 7 minutes before

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Special weather statement, Jul 21, 2:58 PM CDT, 6 minutes before

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Special weather statement, Jul 21, 3:01 PM CDT, 3 minutes before

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The office that day

Everything else NWS Memphis, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 7:06 PM CDT	Special Weather Statement	MEG	Tate	24 min
Jul 20, 8:22 PM CDT	Special Weather Statement	MEG	Lafayette	53 min
Jul 20, 8:36 PM CDT	Severe Thunderstorm Warning	MEG	Calhoun, Lafayette, Yalobusha	39 min
Jul 20, 10:34 PM CDT	Severe Thunderstorm Warning	MEG	Lee, Pontotoc, Union	41 min
Jul 21, 1:41 AM CDT	Special Weather Statement	MEG	Pontotoc	34 min
Jul 21, 2:29 AM CDT	Special Weather Statement	MEG	Monroe	31 min
Jul 21, 1:55 PM CDT	Special Weather Statement	MEG	Tunica	35 min
Jul 21, 3:01 PM CDT	Special Weather Statement	MEG	DeSoto	29 min
Jul 21, 2:57 PM CDT	Special Weather Statement	MEG	Hardin	33 min
Jul 21, 2:58 PM CDT	Special Weather Statement	MEG	Phillips	32 min

Nearby

Heat Advisories in Mississippi, 2012 Heat Advisories in Tennessee, 2012 Heat Advisories in Arkansas, 2012 Every heat advisory in 2012

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.