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 06 September 2026 A review of last month's weather Here is a link to a YouTube clip giving an animated loop of the isobars and streamlines For last month is at youtu.be/yc2pJnX6RVU Most of the month brought anticyclones along 30 to 40south but passing troughs with lows crossed New Zealand on 9, 14-15 and 28-29 August The fascinating feature of the month was the number of lows forming near the equator, a facet of this strengthening El Nino. In an El Nino the Walker Circulation over the Pacific equator shifts so that its rising pillar gets close to 180deg/ Kirimati. In an El Nino the Walker Circulation over the Pacific equator shifts so that its rising pillar gets close to 180deg/ Kiribati. Sea Surface temperature anomalies from psl.noaa.gov/map/clim/sst.shtml El Nino 's warmth in the eastern equatorial pacific continues to intensify , and that cooler patch on its southwest side over Southwest pacific is bringing dry conditions . A time/longitude plot shows anomalies now getting over +4 degrees C This is record breaking. Average isobars for past month The subtropical ridge has weakened in north Pacific. In the south Pacific it has resumed between New Zealand and South America and weakened over Australia. Pressure anomalies for past two months From www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html The anomaly pressure pattern for last month shows well above normal pressures between Queensland and northern New Zealand, surrounded by a moat of lower than normal pressures. The 1020 isobar has shifted north across Tasmania and extended eastwards along 30S to east of New Zealand. TROPICS Tropical cyclone activity increased sharply during the week, with Tropical Storm Edouard lashing the U.S. Gulf Coast with strong winds and dumping nearly 2 feet of rain on portions of eastern Texas. . Former Typhoon Saidel triggered evacuations and transport disruptions in China's Zhejiang province with tropical storm force. . Several other tropical cyclones spun up over the open waters of the Atlantic, and the eastern, central and western Pacific Ocean Hawaii is now under threat from both LOWELL and KARINA. WEATHER ZONES High H1 south of Tahiti at30S is moving off to the southeast. Low L1 and L2 belong to a trough crossing New Zealand on Monday then moving off to the east A zone of light winds on the north side of this system is travelling eastwards in tandem along 20S, fading the trade winds. Another low from the Southern Ocean and associated trough is expected to cross southern New Zealand on Thursday and Friday. Avoid. High H2 in Aussie bight by Wednesday is expected to travel into central Tasman Sea by end of the week. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 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. >>>>>>>>>>>>>>>>