jacksonでnullpointerがでる…

jackosonでjsonを読み込みましたが、うまくいきません
ヌルポインターが出ます
原因を昨日から追求していますがわかりませんでした
jsonはライブドアの天気apiです
aeraという項目は読み込むことができましたが
telopという項目は配列になっておりますがそこができないのです

public void tenki(String location, String area) throws MalformedURLException, IOException {
        this.area = area;
        URL url = new URL("http://weather.livedoor.com/forecast/webservice/json/v1?city=" + location);
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setRequestMethod("GET");
        con.connect();
        String json_st = "";
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()))) {
            String line = "";
            while ((line = reader.readLine()) != null) {
                json_st += line;
            }
            System.out.println(json_st);
        }
        ObjectMapper ob = new ObjectMapper();

        JsonNode json = ob.readTree(json_st);
        area = json.get("title").textValue();
        Weather = json.get("forecasts").get("telop").textValue();//ここでヌルポインタが発生する...

        System.out.println(area);

    }
}

jsonの例です(大阪)
{
	"pinpointLocations": [
		{
			"link": "http://weather.livedoor.com/area/forecast/2710000",
			"name": "大阪市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2714000",
			"name": "堺市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720200",
			"name": "岸和田市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720300",
			"name": "豊中市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720400",
			"name": "池田市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720500",
			"name": "吹田市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720600",
			"name": "泉大津市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720700",
			"name": "高槻市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720800",
			"name": "貝塚市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2720900",
			"name": "守口市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721000",
			"name": "枚方市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721100",
			"name": "茨木市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721200",
			"name": "八尾市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721300",
			"name": "泉佐野市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721400",
			"name": "富田林市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721500",
			"name": "寝屋川市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721600",
			"name": "河内長野市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721700",
			"name": "松原市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721800",
			"name": "大東市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2721900",
			"name": "和泉市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722000",
			"name": "箕面市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722100",
			"name": "柏原市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722200",
			"name": "羽曳野市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722300",
			"name": "門真市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722400",
			"name": "摂津市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722500",
			"name": "高石市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722600",
			"name": "藤井寺市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722700",
			"name": "東大阪市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722800",
			"name": "泉南市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2722900",
			"name": "四條畷市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2723000",
			"name": "交野市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2723100",
			"name": "大阪狭山市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2723200",
			"name": "阪南市"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2730100",
			"name": "島本町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2732100",
			"name": "豊能町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2732200",
			"name": "能勢町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2734100",
			"name": "忠岡町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2736100",
			"name": "熊取町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2736200",
			"name": "田尻町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2736600",
			"name": "岬町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2738100",
			"name": "太子町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2738200",
			"name": "河南町"
		},
		{
			"link": "http://weather.livedoor.com/area/forecast/2738300",
			"name": "千早赤阪村"
		}
	],
	"link": "http://weather.livedoor.com/area/forecast/270000",
	"forecasts": [
		{
			"dateLabel": "今日",
			"telop": "雨",
			"date": "2017-10-29",
			"temperature": {
				"min": null,
				"max": {
					"celsius": "18",
					"fahrenheit": "64.4"
				}
			},
			"image": {
				"width": 50,
				"url": "http://weather.livedoor.com/img/icon/15.gif",
				"title": "雨",
				"height": 31
			}
		},
		{
			"dateLabel": "明日",
			"telop": "曇のち晴",
			"date": "2017-10-30",
			"temperature": {
				"min": {
					"celsius": "12",
					"fahrenheit": "53.6"
				},
				"max": {
					"celsius": "15",
					"fahrenheit": "59.0"
				}
			},
			"image": {
				"width": 50,
				"url": "http://weather.livedoor.com/img/icon/12.gif",
				"title": "曇のち晴",
				"height": 31
			}
		},
		{
			"dateLabel": "明後日",
			"telop": "晴れ",
			"date": "2017-10-31",
			"temperature": {
				"min": null,
				"max": null
			},
			"image": {
				"width": 50,
				"url": "http://weather.livedoor.com/img/icon/1.gif",
				"title": "晴れ",
				"height": 31
			}
		}
	],
	"location": {
		"city": "大阪",
		"area": "近畿",
		"prefecture": "大阪府"
	},
	"publicTime": "2017-10-29T11:00:00+0900",
	"copyright": {
		"provider": [
			{
				"link": "http://tenki.jp/",
				"name": "日本気象協会"
			}
		],
		"link": "http://weather.livedoor.com/",
		"title": "(C) LINE Corporation",
		"image": {
			"width": 118,
			"link": "http://weather.livedoor.com/",
			"url": "http://weather.livedoor.com/img/cmn/livedoor.gif",
			"title": "livedoor 天気情報",
			"height": 26
		}
	},
	"title": "大阪府 大阪 の天気",
	"description": {
		"text": " 近畿地方は、前線や台風第22号の影響で雨が降っています。\n\n 今日の近畿地方は、前線や台風第22号の影響で、雷を伴い非常に激しい\n雨が降り、南部では大荒れの天気となるでしょう。\n\n 明日の近畿地方は、寒気や湿った空気の影響で、おおむね曇りとなり、北\n部では雨の降る所がある見込みです。",
		"publicTime": "2017-10-29T10:38:00+0900"
	}
}

エラー内容は
Exception in thread "main" java.lang.NullPointerException
at gotenki.tenki(gotenki.java:58)
at main.tenki(main.java:181)
at main.main(main.java:133)
mainの方は呼び出しメソッドで引数に間違いはありません
ぜひどうすればいいのかご教授ください