* WHAT. Heat index values up to 107 expected. * WHERE. Portions of central, southeast, southwest, and western Arkansas. * WHEN. From noon today to 8 PM CDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 105 expected. * WHERE. Bradley, Cleveland, Desha, Drew, Lincoln, Calhoun, Clark, Dallas, Ouachita, and Pike Counties. * WHEN. Until 8 PM CDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 109 expected. * WHERE. Portions of south central and southwest Arkansas, north central and northwest Louisiana, southeast Oklahoma, and east and northeast Texas. * WHEN. From 10 AM this morning to 7 PM CDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 109 degrees. * WHERE. Portions of south central and southwest Arkansas, north central and northwest Louisiana, and east and northeast Texas. * WHEN. Until 7 PM CDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. A complex of showers and thunderstorms will shift south through portions of East Texas, extreme Southern Arkansas, and North Louisiana this afternoon, which will result in cooler conditions for the mid and late afternoon hours. This may result in portions if not all of the Heat Advisory area being cancelled early.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 465 IN EFFECT UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING AREAS IN ARKANSAS THIS WATCH INCLUDES 3 COUNTIES IN SOUTH CENTRAL ARKANSAS UNION IN SOUTHWEST ARKANSAS COLUMBIA LAFAYETTE IN LOUISIANA THIS WATCH INCLUDES 17 PARISHES IN NORTH CENTRAL LOUISIANA CALDWELL GRANT JACKSON LA SALLE LINCOLN OUACHITA UNION WINN IN NORTHWEST LOUISIANA BIENVILLE BOSSIER CADDO CLAIBORNE DE SOTO NATCHITOCHES RED RIVER SABINE WEBSTER IN TEXAS THIS WATCH INCLUDES 14 COUNTIES IN NORTHEAST TEXAS ANGELINA CHEROKEE GREGG HARRISON MARION NACOGDOCHES PANOLA RUSK SABINE SAN AUGUSTINE SHELBY SMITH UPSHUR WOOD THIS INCLUDES THE CITIES OF ARCADIA, BERNICE, BIG SANDY, BOSSIER CITY, BRADLEY, CARTHAGE, CENTER, CLARKS, COLFAX, COLUMBIA, COUSHATTA, DRY PRONG, EL DORADO, FARMERVILLE, GIBSLAND, GILMER, GRAYSON, HAWKINS, HAYNESVILLE, HEMPHILL, HENDERSON, HOMER, JACKSONVILLE, JEFFERSON, JENA, JONESBORO, LEWISVILLE, LOGANSPORT, LONGVIEW, LUFKIN, MAGNOLIA, MANSFIELD, MANY, MARSHALL, MARTIN, MIDWAY, MINDEN, MINEOLA, MONROE, MONTGOMERY, NACOGDOCHES, NATCHITOCHES, OLLA, PINELAND, PLEASANT HILL, QUITMAN, RINGGOLD, RUSK, RUSTON, SAN AUGUSTINE, SHREVEPORT, SPRINGHILL, STAMPS, STONEWALL, TYLER, WINNFIELD, WINNSBORO, AND ZWOLLE.