Bobgram Heat Domes

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 28 June2026 Heat Domes A severe "heat dome" gripped the UK and Western Europe, shattering June temperature records. A "heat dome" happens when a large, strong area of high pressure (a big fat High or BFH) coincides with light winds aloft and so gets parked over a region. It acts like a lid on a pot. It traps hot air and pushes it down toward the ground. This sinking air dries out the clouds. Without clouds to block the sun, the ground gets very hot, which causes the air temperatures to spike. So far humans have caused the planet to heat up by 1.36C above levels of the late 1800s, leading scientists reported earlier this month. That might not sound a lot. But even a small increase in the Earth's average temperature can shift heat extremes to much higher levels. All this has gone viral in a post on Facebook: comparing a mock up forecatss done in 2012 showing French temperature in 2050 compared with an actual forecast for France last week. www.facebook.com/JeffBerardelli/posts/when-reality-surpasses-fictiontop-fict ional-forecast-for-august-2050-broadcast-b/1551964656500367/ Go figure.. TROPICS The latest cyclone activity report is at zoom.earth and tropic.ssec.wisc.edu and Tropical Cyclone Potential is from www.ospo.noaa.gov/products/ocean/tropical/tcfp/ . Tropical Storm Arthur soaked parts of eastern Texas and Louisiana. . Japan braced for a rare one-two punch from Typhoon Mekkhala and Tropical Storm Higos, which were expected to unleash widespread flooding within days of each other's arrival. Tonight there are no named storms but we can see a new tropical depression building this week over Micronesia. WEATHER ZONES Weather Zones Mid-week GFS model showing isobars, winds, waves (purple), rain (red), MT (Monsoonal trough), STR (Subtropical Ridge), SPCZ (South Pacific Convergence Zone) CZ (Convergence Zone) SPCZ is expected to have a normal week and still be situated from Solomon Islands to Samoa. Low1 to NE of NZ extending a trough eastward and has a ridge on its northside over Tonga->Cooks. High H1 near 42S 150W and High H2 1033hPa over Tasmania act like shoulders with the Low as the head, all moving east. Low l2 from the west is expected to reach Tasmania by Thursday and then turn into a complex muti-centred low over NZ from Sunday 5 to Thu 9 July. Rain accumulation for next week below. Wind accumulation for next week from windy.com above >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 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. >>>>>>>>>>>>>>>>