Cyclone Arnab Case Study: Forecast, Landfall & Response (Part 2)

Did Cyclone Arnab behave exactly as forecasters predicted? The broad landfall area and dangerous wind strength were forecast well, but the crossing took longer than an earlier short-range time window suggested. That difference is a useful lesson: forecasts are updated as a storm moves, and emergency managers must act on the newest warning while preparing for uncertainty in the exact place and time.

Part 1 covered preparations before landfall. This Part 2 follows what the forecast said, what reports recorded during the crossing, and how warnings were turned into evacuation and response actions. Part 3 looks separately at the damage, relief and recovery work after the storm.

1. What was forecast, and what was observed?

Before landfall, the India Meteorological Department (IMD) forecast a crossing in the broad Bapatla–Visakhapatnam coastal sector, south of Yanam. An IMD bulletin issued at 5:30 a.m. IST on 28 October said the very severe cyclonic storm was very likely to cross close to south of Yanam within the next two hours. It forecast maximum sustained winds of 115–125 km/h, gusting to 140 km/h. That was a time-specific bulletin; earlier bulletins had given different windows as the system developed.

IMD’s later account placed the crossing process between 2:00 a.m. and 8:00 a.m. on 28 October, near Narsapur and southwest of Yanam, in the expected coastal sector. Landfall reports described sustained winds around 125–135 km/h and gusts up to 150 km/h. Read carefully: the reported range was somewhat higher than the 5:30 a.m. forecast range, while the predicted coastal zone and severe intensity were broadly similar. The figures are rounded ranges from different updates, so they do not prove that every location experienced the same wind.

2. Why did the crossing take several hours?

“Landfall” is often used as if it were one instant. In a large cyclone, the centre approaches the coast, the eyewall and strongest winds move over land, and the centre finally crosses. Weather bands can stretch far from the centre. IMD therefore reported a crossing process, not a single moment that made the whole district safe. The 2:00–8:00 a.m. interval describes the coastal crossing operation; it does not mean the same wind blew everywhere for six hours.

A forecast window is also not a promise. The storm’s speed, track, size, coastal shape and interaction with land can change the arrival time. At 5:30 a.m., IMD’s “within the next two hours” was a short-range expectation for that update; the later six-hour crossing window includes the full process and an earlier start. These statements can look different because they describe different update times and definitions.

Also readCyclone Arnab Case Study: Before Landfall (Part 1)→

3. How did warnings become response actions?

Before the cyclone arrived, the Union government said the IMD was issuing regular bulletins and that the state had activated control rooms, arranged shelters and moved response teams. NDRF and SDRF teams were placed on standby or deployed, while district officials coordinated transport and evacuation. After the crossing, response priorities shifted to rescue checks, clearing blocked routes, checking power lines, restoring essential services and recording damage.

In a 29 October briefing, the Chief Minister said more than 28,000 people had been moved to rehabilitation centres and described seven review meetings over three days. These are government-reported operational figures. To judge whether the response worked, students would also need district-level information: who was moved, how many returned safely, whether shelters had water and medicine, what areas remained cut off, and how quickly power and roads were restored.

What the numbers can and cannot tell us: an evacuation count shows how many people officials say were moved; it does not show whether all at-risk households were reached or whether the shelters met every need. Likewise, a count of deployed teams is a measure of capacity, not the final result. Part 3 examines the early damage and restoration reports in detail.

4. Was the forecast right—or did the cyclone go beyond it?

The fairest answer is: some elements matched closely, while the short-term timing and reported peak wind values differed. The forecast identified the right broad coastal sector and warned of very severe cyclone winds. The later landfall reports placed the centre in that broad zone, while listing sustained winds and gusts modestly above the 5:30 a.m. forecast bracket. The crossing process also extended beyond the “next two hours” estimate in that bulletin. This is why forecasters issue updates and managers plan for a range of possible conditions.

It would be inaccurate to say the storm was completely unexpected or that every forecast was wrong. It would also be too strong to claim that the forecast perfectly predicted the exact landfall point, minute and local wind. Forecast quality should be assessed across multiple bulletins, at the same issue time and with the same measure—track against track, sustained wind against sustained wind, and time window against observed crossing.

5. What should students learn from the response?

First, use the newest official warning available for the place and time you are discussing. Second, keep the forecast date and issue time next to each number. Third, understand the difference between sustained wind and a short gust, and between the storm’s centre crossing and the period when dangerous weather affects the coast. Fourth, judge response with outcomes: safety, shelter, rescue, service restoration and support for affected families.

One practical lesson for disaster managers is to plan for uncertainty rather than wait for a perfect forecast. Transport, shelters, local warning messages and response teams need to be ready before the exact landfall point is known. After the event, the same records can help answer whether people were reached, which services failed and what should change before the next cyclone.

Also readCyclone Arnab Case Study: Damage, Relief and Recovery (Part 3)→

FAQs

Conclusion: forecasts guide action; evidence tests results

Arnab’s forecast and crossing show why disaster management depends on timely updates and clear communication. IMD identified the broad coastal sector and warned of very severe winds; later reports described a somewhat higher wind range and a longer crossing process than the short-range two-hour expectation in one bulletin. The sensible conclusion is not “the forecast failed” or “everything was exact.” It is to compare each dated forecast with the matching observation, then judge how effectively authorities and communities acted on the warning.

Continue the series: Part 1 · Before landfall  →  Part 2 · Forecast, landfall and early response  →  Part 3 · Damage, relief and recovery.

Sources and evidence notes

• India Meteorological Department, National Bulletin No. 19, 27 October 2026 — earlier forecast for the broad coastal sector and intensity.
• India Meteorological Department, Coastal Bulletin, 28–29 October 2026 — short-range updates, crossing process and subsequent weakening; check issue time on the bulletin.
• Press Information Bureau, preparedness review, 27 October 2026 — official pre-landfall coordination and response readiness.
• The New Indian Express, 29 October 2026 — Chief Minister’s reported review meetings, evacuation and early restoration statements.
• Andhra Jyothy, 29 October 2026 — dated early response and power-restoration figures (Telugu report).
• H View · Part 1: Before landfall — preparedness background for this series.

Editorial note: Forecasts describe what was expected at a specific issue time; observed figures describe later reports. Keep the source, date, time window and measurement beside each comparison. This article is for learning and does not replace current official warnings.