The trick with storms is understanding the exact timing of enemy movements and sound masking. During heavy rain freakers lose about 40% of their detection range which gives you roughly 15 meters of safe approach distance from their standard patrol paths. Thunder claps provide 3-4 second windows where you can sprint without detection, just watch for the initial lightning flash as your cue. When setting up an ambush position yourself about 8 meters from sheltered areas, since enemies tend to seek cover under overhangs or in nearby structures letting you predict their movement patterns.

For bike handling reduce speed by 30% on wet terrain and lean into turns at a 45-degree angle to maintain traction through forest paths. Good spot to practice is the cascade region where you'll find plenty of covered corners for testing stealth approaches. Molotovs work best when thrown into doorways during storms since enemies cluster up, giving you about a 5 second burn window before the rain affects the flames. The timing for melee attacks changes too with enemies having slightly longer recovery animations when stumbling on wet ground roughly 1.2 seconds instead of the usual 0.8 which lets you chain attacks more effectively. Just remember that your own movement sounds are masked at the same time so keep an eye on your radar since you won't hear approaching threats as clearly either

The real key is linking these mechanics together watching for lightning flashes as movement windows then using the thunder to mask your repositioning while enemies are distracted. Takes some practice but the patterns become pretty predictable once you get the timing down.