Bobgram

Bob McDavitt's ideas for sailing around the South Pacific. Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world. Compiled 30 August 2026 Ocean warmth breaks to 70degrees F barrier Full story is at climate.copernicus.eu/copernicus-daily-global-sea-surface-temperature-breaks -2024-record Note that an August maximum is usually lower than the March maximum. Not this year. And this El Nino is expected to get stronger next few months Of particular interest in our region is the moat of cooler than normal sea between New Guinea and Niue . The South Pacific convergence zone has shifted well north and east, and Fiji/Tonga are approaching drought conditions. Logically the cyclone risk this season is also likely to shift north and east. More on that later in September. As for how this impacts the Island hoppers from Tonga to Tahiti: Well, this coming week shows a typical el Nino pattern over the South Pacific , with strong west to southwest winds south of 30S, an expansive subtropical ridge between 20 and 30S, thundery squalls north of 15Sz. Also there is a tendency for secondary lows to form on fronts as they cross New Zealand (as happened 29 Aug and may happen on 11 Sep. And a tendency for tropical lows to form on the NW shoulder of the migratory Highs as may happen around 6 September rover Austral Islands TROPICS . Downpours from Tropical Storm Narra battered northern Vietnam and China's Guangxi region with floods and landslides. . Typhoon Saudel drenched some of Japan's southernmost islands before taking aim on coastal China. . Passing Tropical Storm Moke brought locally heavy rain to Hawaii while Iselle and Julio spun up to the east, followed by Karina and Lowell. WEATHER ZONES SPCZ is north of its normal position High H1 is moving east along 30S south of French Polynesia. L1 belongs to a broad trough that crossed NZ last few days. A following trough is expected to cross the south of NZ on Monday with strong southerly winds and snow to low levels. High H2 over Tasmania tonight is expected to travel northeast into the Tasman Sea /30S region by Wednesday. L2 follows on the south side of H2, and is likely to broaden outwards into three different troughs crossing NZ on 6, 8, and 11 Sept. There is a chance of a secondary forming over North Island on 10 Sept. Avoid arriving in NZ on the day of a passing trough. Low L3 is expected to start forming on Friday near Rarotonga. It may deepen quickly near 30S as it moves off to the southeast and produce a zone of light winds on its northern side. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> If you would like more details about your voyage, check metbob.com Or Facebook at /www.facebook.com/metbobnz/ Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe at bottom). Weathergram archive (with translator) is at weathergram.blogspot.co.nz. Contact is bob@metbob.com or text 64277762212. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>