Hoangminh90,
If no guidance lights onto your parking stand, the use of hand signals during stormy weather is the next best (and safest) thing to do. If your marshaller was connected to your aircraft intercom via his/her headset and the aircraft suffered a lightning strike, your friendly marshaller would get fried through his/her headset and be very lucky to survive. It has happened and no doubt will happen again, although in some countries that I have flown to, if a storm is close to the airport, the ground staff will leave their work area until the storm has passed. Better to arrive slightly late on blox than to dodge a dead/severely injured body on the ramp.
McHale.
