What is a flash appeal? OCHA's timeline and when it gets issued
A flash appeal is the document OCHA issues to ask donors for money in the first days after a sudden-onset crisis: a major earthquake, a cyclone landfall, a flood that displaces hundreds of thousands of people in a week. OCHA drafts it in days, not the weeks a full Humanitarian Response Plan takes, because the funding needs to move while the caseload is still being counted.
If you've drafted one before, you know the pressure isn't the writing. It's the numbers. Donors reading a flash appeal want to see who's affected, where, and by how much, and in the first days after an event that data is thin. Field teams aren't deployed yet. Local authorities are triaging life-safety needs, not filling in damage tables. You're often working from preliminary reports, a few photos from partners on the ground, and whatever remote sensing you can get your hands on.
When does OCHA issue a flash appeal
OCHA and the Emergency Relief Coordinator typically call for a flash appeal within the first 72 hours to a week after a sudden-onset disaster, once the Humanitarian Country Team judges that the national government can't absorb the response alone and international assistance is needed. That judgment weighs scale of displacement, a government request for support, and whether existing response mechanisms in-country can handle the need. A major flood in a country with an active HRP might get folded into that existing plan instead. A cyclone hitting a country with no current response architecture is a clearer case for a standalone flash appeal.
Flash appeal vs humanitarian response plan
The two documents answer different questions on different clocks.
A flash appeal covers the acute phase, usually three to six months, and gets drafted in days. It triggers pooled funds like CERF rapid response grants and gets donors moving before the full scope of damage is confirmed. It's intentionally lean: priority needs, rough caseload estimates, the sectors mobilizing first.
A Humanitarian Response Plan is the longer document, usually annual, built once there's been time for proper needs assessment, cluster coordination, and a full Humanitarian Needs Overview. It's where the detailed, sector-by-sector figures live. Flash appeals sometimes get absorbed into an HRP later in the year, once the emergency phase ends and the response settles into something closer to protracted caseload planning.
If you're drafting a flash appeal, you're writing under the first clock, not the second. The numbers you have at day three are the numbers that go in the document, revised versions notwithstanding.
The OCHA flash appeal timeline, roughly
- Day 0 to 3: event occurs, initial situation reports circulate, government request for international assistance (if any) comes in.
- Day 2 to 5: OCHA, in consultation with the HCT, decides whether to launch a flash appeal versus folding the response into an existing plan.
- Day 3 to 7: appeal drafting, sector leads submit preliminary needs and funding requirements, affected-population and damage figures get compiled from whatever sources are available.
- Day 5 to 10: appeal launches publicly, often alongside a CERF allocation announcement.
- Weeks 2 to 8: revisions as field assessments catch up and replace early estimates.
That second-to-last window, days 5 through 10, is where the damage figures in your draft get the most scrutiny. A ministry estimate of "thousands of homes damaged" doesn't hold up in a document that's about to go in front of donor desks. A structure-by-structure count, even a preliminary one, does.
That's the gap a damage assessment from very-high-resolution imagery is built to close: a defensible count of affected structures, delivered in days rather than weeks, formatted the way appeal tables and pooled-fund allocation sheets already expect, without waiting on field teams who haven't deployed yet. If you're staring down a flash appeal deadline and need a damage count that holds up, take a look at Humanitarian Damage Assessment.