Mobile (3)
Auburn (2)

Array
(
[0] => Array
    (
        [0] => Array
            (
                [city] => Mobile
                [numLocations] => 3
            )

        [1] => Array
            (
                [city] => Auburn
                [numLocations] => 2
            )

    )

)

while($row = mysqli_fetch_assoc($result)){
    $state = $row['state'];
    $stateAbv = $row['stateAbv'];
    $city = $row['city'];
    $numSLocations = $values['cnt'];

    if (!isset($rows[$row['state']])){
        $rows[$row['state']] = array();
    }

    $rows[$row['state']][] = ['city' => $city, 'numLocations' => $numStores];
}

foreach($rows as $state => $cities){
   echo array_column($cities, 'numLocations'));
}