Nembrala Surf Outlook Flags Dawn Southwest Swell on 21 September

Nembrala — — A model-based surf forecast for Nembrala on Monday, 21 September 2026, is calling for a small but long-period southwest swell around dawn, with the best-quality and most powerful conditions currently projected for 5 a.m. local time, according to Surf-Forecast.com’s latest outlook issued on Saturday, 19 September.

Surf-Forecast.com reports that the first swell rated one star or higher in its 16-day outlook is due at 5 a.m. Monday, with a primary swell height of about 0.8 metres, or 2.5 feet, and a period of 16 seconds from the southwest. The same time is listed in the forecast as the break’s best-quality surf, most powerful swell and next surfable swell in the current outlook window.

The forecast notes that winds are expected to be offshore as this swell arrives, although the detailed table presented with the six-day outlook does not specify the exact wind direction at that hour. As with any numerical model, the outlook may change before Monday morning, and surfers are advised to check updated local information and observe the lineup from shore before paddling out.

Key forecast indicators

In its summary for Nembrala, Surf-Forecast.com identifies the Monday 5 a.m. window as the first time in the coming period that surfable swell—rated at least one star—is expected to reach the reef break. At that time, the site lists the primary swell as 0.8 metres at 16 seconds from the southwest, with offshore winds and a calculated wave energy of 302 kilojoules for the most powerful swell during the outlook.

The same outlook distinguishes between the swell aimed at the break and a larger open-ocean swell that is not directed toward the surf spot. The largest open-ocean swell in the forecast is listed at 1.4 metres with an eight-second period at about 2 a.m. Monday, while the smaller but longer-period 0.8-metre swell is the one projected to produce the best surf at Nembrala.

A longer swell period often indicates more widely spaced waves and can be associated with more organised surf, but it does not by itself determine the size or suitability of individual waves breaking on the reef. Local bathymetry, tide state, short-term wind changes and the condition of the reef can all affect how the forecasted swell translates into rideable waves.

• Time: 5 a.m. WITA, Monday, 21 September 2026, as the first 1-star-or-higher swell in the outlook
• Swell: 0.8 metres (about 2.5 feet) primary swell aimed at the break
• Period and direction: 16-second period from the southwest
• Wind: Forecast offshore when the swell arrives, with detailed direction not specified in the six-day summary
• Wave energy: 302 kilojoules in the listing for the most powerful swell in the outlook

Short-range weather and sea-temperature information for Nembrala from the same provider indicates very warm water and air temperatures at this time of year, with a present sea temperature of about 27.2°C and typical values ranging between roughly 26.6°C and 28.2°C. The site describes sunny, very warm conditions that generally do not require thick neoprene, although sun protection such as a rash vest is recommended.

Reef setting, seasonality and safety

Surf-Forecast.com describes Nembrala as an exposed reef break that receives consistent surf. Its statistics and regional guidance point to the dry-season months as the most reliable period for waves, with swells large enough for good surfing conditions occurring for the vast majority of days in October and frequent surfable swells through much of the March–November season.

Separate regional material from Nemberala Beach Resort identifies Nembrala Left as the main break in front of the resort and the premier wave in the area, noting that the spot picks up south to southwest swells generated across the southern Indian Ocean.

According to the resort and other regional guides, peak surf season typically runs from about May through August, with a broader March–November window for consistent surf, and southeast to east-southeast trade winds during the core dry season can provide favourable offshore conditions for the left-hand reef.

Both the forecast and regional guides emphasise that actual conditions on any given day depend on the interaction of swell, tide, wind and reef characteristics. None of the sources consulted provide real-time information on access, crowd levels, lifeguard coverage or specific hazard advisories for Monday morning. Surfers planning to visit Nembrala on 21 September are therefore advised to confirm current local conditions and safety information with operators or authorities on site before entering the water.

Sources

• Surf-Forecast.com – Nembrala Surf Forecast and Surf Report (six-day/16-day outlook)
• Nemberala Beach Resort – Surfing at Nemberala Left
• Indonesian Surf Guide – Ultimate Guide to Surfing in Rote, Indonesia