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 Rainfall deciles for the 18 months to August 2018 show large parts of the Murray-Darling Basin are in the lowest 10% of all 18-month periods since 1900. BoM. |
 Outlook is for warm, dry weather to continue
Sat 1 Sep 2018
The BoM's Spring Outlook paints a dismal story for those hoping for an end to the drought. It indicates warmer and drier than average conditions are expected across many parts of Australia in the coming three months. The greatest likelihoods of a drier-than-average season are more than 80% in southern NSW, VIC and SW WA, while the greatest chances of warmer-than-average days are in the north and west of the country.
BoM manager of long range forecasting, Dr Andrew Watkins, rather stated the obvious in releasing the outlook when he said "These regions need a lot of rain to break the current drought." The map above shows that much of one of the worst affected areas, the Murray Darling basin, has had so little rain in the past 18 months that it lies in the bottom 10% of all 18-month totals in the past 119 years. The map for all Australia is here.
The chances of an El Niño developing, which traditionally produce warmer and drier conditions, are given as double the normal. However, Dr Watkins urges caution saying "it is important to remember that the strength of an El Niño event doesn't always translate into the conditions we see. For example, in the past we've had strong El Niño events accompanied by mild conditions and weaker El Niño events accompanied by severe conditions." However, "A number of international models are also predicting [that] a positive Indian Ocean Dipole event could potentially develop during spring which would further exacerbate the drying trend."
The 2018 Spring Outlook is the first end-of-month seasonal outlook produced using the Bureau's upgraded climate outlook model. It provides more accurate and localised outlooks than was previously possible and is certainly evident when you see the new-look charts. The full current Outlook is here* and a briefer archived version is here. The full suite of BoM climate forecast reports is here, including tropical outlooks and monitoring, when the northern wet season is likely to begin, a summary of model outlooks from around the world, and El Niño-Southern Oscillation monitoring and forecasts from BoM, WMO and NOAA.
 Sat 1 Sep 2018 Super Typhoon Jebi heads for Japan and Russia. Claimed to be the most powerful so far in 2018, Category 5 Super Typhoon Jebi was located on the afternoon of Friday 31st EST about 1,500km SE of Japan, and performing an arc that would see it crossing the largest island of Japan, Honshu, just west of Tokyo. This ERCC map, based on forecast information from the Joint Typhoon Warning Center, shows the forecast track at that time which has not changed much in more recent updates.
While Jebi is forecast to weaken as it approaches Japan on Tuesday, it is still expected to cross the coast carrying 160km/h sustained winds before skirting the coastal Primorsky district of Russia, north of Vladivostok. In both countries, heavy rain with the cyclone will be the greatest danger. Over 150 people died and two million were evacuated in Japan in early July in the worst flooding in over 30 years, while so far in August the country has endured two typhoons and a tropical storm [Newshub, USA Today]. Primorsky has not been so badly hit, but recent heavy rain and flooding† has left the ground sodden and ill-prepared for the forecast 250 to 500mm of rain.
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