Given the environment in Dubai and Abu Dhabi, where humidity levels can be relatively high, mold growth is more likely after such weather events. The greenish-brown stain on your ceiling suggests the presence of mold, but it’s essential to confirm this through a professional inspection. This is especially important as per the regulations set by the UAE Ministry of Climate Change and Environment (MOCCAE), which require documentation for any remediation activities.

The first step you should take is to cease using the affected area until a professional assessment has been conducted. Avoid touching or cleaning the stain directly, as this can spread mold spores. Instead, isolate the area by covering it with plastic sheeting to prevent the spores from spreading throughout your home.

Given the urgency of the situation and considering the health implications, it would be advisable to contact a professional remediation service such as Saniservice at 800-MOLDS or 800-66537. They are equipped with the necessary expertise to conduct an inspection and provide a detailed plan for mold removal.

In addition to the immediate action of calling in professionals, there are some steps you can take to mitigate the situation until help arrives:

1. Ensure proper ventilation: Open windows if possible, but avoid using fans that may circulate spores.
2. Keep the area dry: Use dehumidifiers or air conditioners if necessary to reduce moisture levels.
3. Document everything: Take photos and notes of the conditions for potential insurance claims or remediation records.

Remember, mold can grow rapidly under the right conditions, so swift action is paramount. Regular maintenance checks and early intervention can significantly prevent more extensive issues in the future.