Tropical Storm Chantal succumbed to wind shear last night, the lower and middle layers of the storm were moving faster than its upper level support. In addition, the storm was embedded in very strong easterly trade winds which makes it hard for developing systems to form a closed low by limiting the potential for westerly winds on the southern side of a center. However, the remnants of Chantal still feature a sharp tropical wave and a mid level circulation, both of which need to be monitored for redevelopment near Cuba in the coming days. In fact, several reliable models do redevelop Chantal in the Bahamas and take it into the US East coast AND the National Hurricane Center is giving the remnants a medium 30% chance of redeveloping in the next 48 hours. Although Chantal is no longer a Tropical Cyclone, gusty if not squally showers are still possible in the Greater Antilles and the Bahamas as the tropical wave passes, these showers could produce heavy rain that could lead to isolated flooding. Chantal’s remnants are not a threat to Bermuda.
Heat of the day convective showers (with temperatures in the mid-80s), and small scale areas of convergence embedded in the Bermuda segment of the Bermuda-Azores high are continuing a slight chance for isolated showers as winds remain very light and sometimes variable. The center of high pressure is parked on top of the island allowing for these conditions. However, a trough in the central Atlantic has been cut off from mid-latitude westerly flow and is beginning to retrograde towards Bermuda in the easterly flow south of the Bermuda-Azores ridge of high pressure that is re-establishing itself. As the trough, now inverted after being cut off from the westerlies, approaches this weekend, showers and thunderstorms move in along with an increase in easterly winds. These winds may increase enough to warrant small craft advisories. Although this inverted trough is expected to be very sharp, it is very unlikely that it will become a Tropical Cyclone. This will be much needed rain as no widespread rain event has impacted the island since mid-late June – about 3 weeks. See the latest official forecasts and other weather products for Bermuda at the Bermuda Weather Service.
Additionally, in the Atlantic, a strong tropical wave has emerged off the coast of Africa and bears monitoring for future tropical development as it does appear to have decent low level structure. However, it will have to deal with dry dusty Saharan air to its north, and may run into strong trade winds like Chantal down the line.
Meanwhile, in the Western Pacific, Typhoon Soulik continues its approach to Ishigakijima and Taiwan. The Typhoon ingested some dry air that disrupted its very well formed core yesterday. Despite this, it remains a powerful storm with 10-minute sustained winds estimated at 100mph by the Japanese Meteorological Agency and 1-minute sustained winds estimated at 110mph by the Joint Typhoon Warning Center making it a category 2 equivalent typhoon. There is some room for re-intensification as the storm works out the dry air and re-builds its core thunderstorms. But it doesn’t have a lot of time to do that before interacting with land, so the current forecasts only strengthen it back to 120mph 1-minute sustained winds, or category 3 equivalent. Typhoon Soulik is a fairly large cyclone, with tropical storm force winds extending more than 200miles from its center. Flooding and mudslides along the storm’s path (especially in the mountainous terrain of Taiwan), along with damaging winds and coastal storm surge flooding nearer the center are likely to be the biggest impacts from this Typhoon in Japan, Taiwan, and China.