When we are aware that something dangerous is going to happen, we can prepare ourselves to face it and tide over the danger.
Forewarned here means getting a hint or a warning signal about the impending danger. And forearmed refers to the actions which we take to plan and equip ourselves to face that danger.
Philippines is in that region of the Pacific Ocean that is generally termed as The Ring of Fire since volcanic activity and earthquakes are a common occurrence here.
Philippines has almost 22 active volcanoes and Mayon is one of them. More than 1,200 people were killed and an entire town was buried when it erupted in 1814.
In August 2006 when the volcano showed signs of erupting, the authorities immediately swung into action and warned all the villagers within a radius of 10 km to be careful.
Workers put up warning signals asking people not to venture within 4.5 miles from the crater since the volcano could erupt anytime.
The Philippine Institute of Volcanology and Seismology was well aware of the danger of the volcano erupting and therefore was able to move people in the neighboring areas to safer places.
Thus advance information on the impending disaster certainly gave them time for emergency measures to be put in place. So in this case, the forewarning of seismic activity helped them to get ready to face extreme situations thus avoiding loss of life and property.
In real life we too can protect ourselves from dangerous situations by heeding to the advice of the authorities. We have to follow the good advices of the experienced people in our daily lives.
For example we are often warned by the police to refrain from accepting food or packages from unknown people. We hear stories of how passengers are duped of their belongings by the biscuit bandits who offer them snacks that contain drugs which results in them becoming unconscious.
Many people who have quite often traveled in trains and log-distance buses have come across such incidents which might have duped them of
their belongings. The innocence of many people has placed them in a bad-conditions to face the lose of valuables and belongings.
Similarly we are always warned not to touch unclaimed baggage soon after terrorist attacks for fear that they might contain explosives.