Rough start when wet outside

[2003 XLT v8]

Hello everybody.
I have a 2003 explorer 4 .6 - V8.
Recently when its damp outside and I start the car the
service light goes on and it runs rough , it feels like 1 cylinder isn't firing. After it dry's out the light goes off and it run regular again. The car has 95k miles on it ,
Anybody have an idea of what this is, damaged wires ? sparkplug wire issue ? and can fix it myself or is it time to
take it in for the 100k tune up. thanks S

 

[Joe in NY]

You have at least one bad coil. I had a similar problem. When humid out mine would miss fire under load (acceleration). My #5 coil went. You should get a service light which means there is a code.

 

[2003 XLT v8]

Should I replace the coils ?

 

[SPSully]

yup