The weather pattern is evidence
Write down which room is affected, where the stain appears and what the weather was doing. If you noticed the direction of the wind, include it without guessing a speed. A recurring pattern is useful even when the roof is dry during inspection.
Record whether the leak starts immediately or later. Water can travel behind cladding or along framing before it reaches a visible surface. The time delay can be part of the investigation rather than a reason to dismiss the connection with rain.
Junctions matter as much as the broad roof surface
Walls, chimneys, valleys and penetrations interrupt the covering. Flashing routes water around these interruptions, and its relationship to adjacent materials matters. A defect above the roof-wall junction may let water enter behind otherwise sound roofing.
Roof edges and a shallow addition can introduce other pathways. The assessment should examine the assembly appropriate to the symptom rather than assume every intermittent leak needs a new field of shingles.
Why more sealant may not resolve it
Sealant can be part of a specified detail, but a visible bead is not proof that the underlying water path is correct. Covering a gap may leave water trapped or allow it to reappear elsewhere. The repair needs to explain what failed and how water will leave the assembly afterward.
Ask whether roofing, masonry, siding or another trade is responsible for the relevant component. If a proposal stops at the roof surface while water enters from a wall above, clarify the missing part of the scope before work begins.
Turn an intermittent symptom into an assessable request
Collect safe photos, earlier invoices and a simple weather timeline. Do not try to reproduce a leak by spraying the roof yourself; uncontrolled water testing can create damage and misleading results. Any investigative test should be agreed with the professional conducting it.
After repair, track the same symptom rather than judging success only by a dry day. Report recurring water promptly with the date and conditions. Follow-up is easier when the initial findings and completed scope are documented.
One more useful question
Does a leak during wind mean shingles blew off?
Not necessarily. Water may enter at an edge, wall, flashing or penetration. Missing material is one possibility among several that need assessment.
Further technical reading
Manufacturer references are educational; they do not imply certification or affiliation.
GAF: understanding roof flashingGAF: recognizing roof damage