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12/18/2018, 7:57 pm EST

Australia Season 1-3 Ahead Outlook

+IOD Weakens; Weak El Nino In-place. Dryness shifts westward. Executive Summary: The outlooks indicate a tendency of drought to shift westward during the summer season with beneficial rains across the northeast areas. A hotter than normal summer across western and southern Australia. El Nino is weak to moderate while +IOD is forecast to weaken. Climate discussion: The global SSTA patterns affecting the Australian climate (Fig. 1) include a choppy weak El Nino, positive phase Indian Ocean dipole (+IOD) expected to weaken, a “warm blob” east of Australia which could enhance East Australia heat mid-summer and then enhance tropical cyclone risk late summer and an evolving warm phase of the Pacific decadal oscillation (+PDO) which correlates to a strengthening El Nino. In November, Australian soil moisture anomalies trended wetter (Fig. 2) largely in-part due to a late season polar vortex south of Australia (Fig. 3) emitting short wave energy (cold fronts) causing the rainfall. The ENSO analog forecast (Fig. 4) features two modern-day weak to moderate El Nino episodes and three other El Nino regimes from several decades ago. The more recent El Nino episodes are counted twice in the constructed analog climate forecast for winter into spring. Forecast confidence is average to above average on the 3-month outlook which is agreeable to weak-to-moderate El Nino. However, the analogs differ in the cool-to-cold season 2019 forecast as the modern day analogs decelerate to La Nina while the older analogs favor El Nino continuing. Fig. 1: Current global SSTA and regions of influence on Australia climate. Fig. 2: Australian anomalous soil moisture regimes as of Nov. 30, 2018. Fig. 3: The polar vortex has split in the southern hemisphere with one center just south of Australia emitting short wave energy into Australia. Fig. 4: The Climate Impact Company ENSO analog forecast through summer 2019-20. Climate outlooks: The outlooks begin with meteorological summer 2018-19 and autumn 2019 compared to previous forecast with the preliminary winter 2019 outlook added. DEC/JAN/FEB 2018-19: The winter 2018-19 outlook indicates cooler and wetter than normal climate across Queensland while anomalous heat is most dominant in western and southern continent. The strongest dryness is in northwest Australia and also southeast Queensland. The forecast is adjusted hotter and drier western sections while the northeast is wetter. Fig. 5-6: The Climate Impact Company meteorological summer 2018-19 temperature and precipitation anomaly forecast for Australia. Previous forecast is below. MAR/APR/MAY 2019: The forecast has changed since the previous outlook although forecast confidence remains below average depending on El Nino strength. Indicated is a cool regime in Western Australia while a warm anomaly is centered on New South Wales. The precipitation forecast trends wetter in Southeast Australia. Fig. 7-8: The Climate Impact Company meteorological autumn 2019 temperature and precipitation anomaly forecast for Australia. Previous forecast is below. JUN/JUL/AUG 2019: The preliminary outlook for next winter is chilly across north and northeast continent while anomalous warmth is expected across Western Australia. The precipitation outlook is somewhat benign with marginal dryness in southwestern sections and wet in the northeast coastal portion of New South Wales. Fig. 9-10: The preliminary Climate Impact Company meteorological winter 2019 temperature and precipitation anomaly forecast for Australia.