How to forecastng in AR model

Hi.guys.

I want to forecasting like this ↓

tic
data = iddata(sin(0.1*[1:100])',[]);
plot(data)
sys = ar(data,2);
K = 100;
p = forecast(sys,data,K);
plot(data,'b',p,'r'), legend('measured','forecasted')
toc

And I try this ↓

data =  iddata(g_Fresult_data_4{1,1}(:,3),[]) ;
plot(data) ;
sys = ar(data,2);
K = 98 ;
p = forecast(sys,data,K);
plot(data,'b',p,'r'), legend('measured','forecasted')

g_Fresult_data_4{1,1}(:,3),[] is 98x7 double in 1x1 cell structure. (weather data)

    WD      WS      T       H       HI        UV      AP
  260.542  3.138  11.111  51.666  249.800   8.666  998.825
  210.237  3.235  11.577  50.800  274.266  10.200  998.827
  226.260  3.186  12.085  49.066  359.000  12.066  998.581
  230.127  3.127  12.777  47.800  328.800  11.866  998.617
     .       .       .       .       .       .        .
     .       .       .       .       .       .        .

But plot is resulted below picture.

I do not know yet.. because it is the first time forecasting. I think 'sys=ar~' will be revised. help me.