$valley = array();
$peak = array();

foreach ($data as $date => $events) {
    $v_cycle = 0;
    $p_cycle = 0;

    $valley[$v_cycle] = array('blank',999);
    $peak[$p_cycle] = array('blank',-999);

    $current = 0;
    $previous = 'blank';
    $direction = 0;

    echo '<table border="1">' . PHP_EOL;
    echo ' <tr><th>Date</th><th>Time</th><th>PREDICTED</th><th>OBSERVED</th><th class="dev">DIRECTION</th></tr>' . PHP_EOL;

    foreach ($events as $time => $readings) {
        $predicted = $readings[0];
        $observed = $readings[1];
        $current = ($observed != '---' ? $observed : $predicted);

        if ($previous > $current && $previous != 'blank') {
            if ($direction == 1) {
                $peak[$p_cycle++] = array($time,$current);
            }
            $direction = -1;
        }
        if ($previous < $current && $previous != 'blank') {
            if ($direction == -1) {
                $valley[$v_cycle++] = array($time,$current);
            }
            $direction = 1;
        }

        echo ' <tr><td>' . $date . '</td><td>' . $time . '</td>';
        echo '<td>' . sprintf('%+.2f',$predicted) . '</td>';
        echo '<td>' . ($observed != '---' ? sprintf('%+.2f',$observed) : $observed) . '</td>';
        echo '<td class="dev">' . ($direction == 1 ? 'UP' : ($direction == -1 ? 'DOWN' : 'START')) . '</td>';

        $previous = $current;
    }

    for ($x=0; $x<(sizeof($valley) >= sizeof($peak) ? sizeof($valley) : sizeof($peak)); $x++) {
        echo '<tr><th colspan="2">Peak ' . ($x+1) . ': ' . $peak[$x][0] . '</th>';
        echo '<th colspan="2">Valley ' . ($x+1) . ': ' . $valley[$x][0] . '</td></tr>' . PHP_EOL;
    }
    echo '</table><hr>' . PHP_EOL;

    unset($peak);
    unset($valley);
}