The East Coast Low

The northwest cloudband full of moisture picked up from the Indian Ocean, slowly moved in a southwesterly direction across the country  giving much needed rainfall to drought  ridden areas.  Passing through Alice Springs it hailed leaving the area snow-like in vivid contrast to the red earth.

A vanguard of the northwest cloud reached Queensland early Saturday 18th June where with other systems It developed into the East Coast Lows we are all too familiar with, having already experienced one a few weeks ago.

At Maleny the first precipitation of the system was at midnight on Saturday and rained continuously and ended at 11.30 pm on Sunday June 19th. Total rainfall for the period of the storm was 117 mm.  Northeast winds were gale force reaching a peak at Maleny of 45 km/hr at 2.15pm on Sunday. We were fortunate not to sustain anything like the damage to property by tornado like winds  at Mooloolaba where roofs have been blown off, cars crushed and powerlines downed.

Maleny’s Hottest June Day on Record

On Thursday 9th we had the hottest day on record with temperature soaring to 27.3ºC.  The previous record was 25.2ºC on June 29th 2003

WW2 D-Day Weather

In the late spring of 1944, most people knew the invasion of mainland Europe was imminent, but very few knew where and when. It was the job of the senior meteorologists to advise the Supreme Commander as to when.

Bomber and fighter aircraft each required different cloud conditions.
Very strict minimum weather conditions were laid down, with different flight criteria for each arm of the operation. Bomber and fighter aircraft each required different cloud conditions. Gliders needed a moonlit night with no fog or mist.

The Army needed firm dry ground, so no heavy rain before the date. The Navy needed winds no stronger than 10 knots, good visibility and no prolonged high winds in the western approaches for the days immediately preceding the operation, thus limiting the size of any waves and swell in the English Channel. These quiet conditions should then persist for as long as possible after the initial assault.

It would have been much easier if the date of the assault could be decided at very short notice, but this was not possible, as a large invasion force could not be kept waiting around indefinitely for suitable weather.

It was decided that the senior meteorologists of the Meteorological Office, the Naval Meteorological Service and the Weather Service of the United States Army Air Force, would work independently on predicting the likely weather patterns. Dr Stagg of the British Meteorological Office, seconded as a Group Captain in the RAF, was appointed as the       co-coordinating forecaster to brief the Supreme Commander and his staff.

The forecasters were concerned with two parts of the forecast – the detailed requirements for the start of the invasion, and the much longer period for the build-up of the troops after that.

At first the meteorologists studied the climatology at the most likely time of the invasion, to give them an idea of the most usual weather for that time of year. This showed that either May or June was probably better than July, but it was already too late for arrangements to be made for May.

The tide, state of the moon and time of sunrise combined favourably on June 3rd and the following two days. A fine quiet spell in late May gave way to more unsettled westerly winds, and by the beginning of June there was a very common weather picture, with an Azores high pressure belt extending into the Bay of Biscay and a frontal system and its attendant low pressure areas stretching from Scotland and into the western Atlantic.

All the forecasting advice now hinged on the movement of the lows and the weather fronts, but in 1944 forecasters trying to see 48 hours ahead was at or beyond the limits of what was possible.

On the strength of this uncertainty on June 3rd, the Supreme Commander postponed the invasion…
It looked as though the weather in the Channel would be marginal for the proposed landings on June 5th. Being sandwiched between the high pressure belt over France and the low pressure further north meant that the south-westerly winds would be too strong and bring in too much cloud, making the bombing in advance of the attack very difficult. On the strength of this uncertainty on June 3rd, the Supreme Commander postponed the invasion for 24 hours.

The three weather centres continued to debate the possible solutions in the weather scenario. Low pressures were developing in the western Atlantic and moving northeast across Scotland. This kept the weather fronts to the northwest and consequently continued to feed in strong south-westerly winds through the English Channel.

The general consensus was that there was likely to be little change in the overall picture, but then unexpected developments occurred on Sunday, June 4th.

Although pressure was falling quickly over Ireland and a cold front was moving quickly east, an observation was being reported from a ship stationed due south of Iceland, which showed sustained, rising pressure. This observation was from a Royal Navy vessel stationed there for the specific purpose of providing meteorological observations from an area, which has a major influence on Britain’s weather patterns.

Stagg realised that nothing could stop the cold front moving through the Channel, and it now also looked as if a low pressure system out in the mid-Atlantic would slow down and intensify. More important, however, was the information from the Navy ship.

Taken together with all the other data, it could indicate that a ridge of high pressure was developing behind the cold front, which was presently sweeping over the Channel. If this continued, there could be enough of a window in the unsettled weather over the Channel, and the assault area, just for the critical hours on Tuesday June 6th.

If this happened, there could be a period of improved weather in the landing zones long enough to allow the first critical assaults to be made on June 6th. By the early hours of that morning, the weather would be suitable for the heavy bombers, although large areas of cloud might curtail later operations. This however, was likely to be high enough to enable the fall of shot to be spotted for the naval heavy guns.

Stagg now had to persuade the Supreme Commander to take advantage of this most unlikely break in the very unseasonable weather and hope that the German forecasters on the French coasts had not spotted this subtle change in the weather pattern.

…the weather outlooks had changed so violently in recent days.
Stagg informed General Bull on the Sunday evening of the probability of the weather window on the 6th (Tuesday), but it was treated with some understandable caution, since the weather outlooks had changed so violently in recent days.

On Sunday evening (June 4th), the Commanders-in-Chief and their senior staff assembled in the library. Stagg and Yates entered and briefed them on the recent weather developments, describing the latest optimism. Air Chief Marshal Tedder asked what confidence Stagg had in the forecast he had just given, and was told that the confidence was high for a spell of fine weather behind that cold front, but not so high for a continued settled spell after that.

The Supreme Commander then discussed the position with his Chiefs. The atmosphere was tense and grave. He then asked General Montgomery if there was any reason why they should not launch the attack on June 6th, to which Montgomery replied, “No. I would say go”

They all met again at 0415 on Monday, June 5th. The room was quiet when General Eisenhower asked Stagg for his opinion, and was told that no substantial change had taken place since the last briefing and that fair weather would extend through all of southern England that night and last into Tuesday afternoon.

There would be small amounts of cloud and the winds in the assault area would be Beaufort Force 3 to 4, locally Force 5. Later on Tuesday it would become cloudier with more unsettled weather at times again between Wednesday and Friday. The relief was immediate. The Supreme Commander broke into a broad smile and told Stagg that if this forecast came off they would all have a celebration when the time came.

The El Niño Episode is Over

El Niño is often, but not always, associated with drought. But the drying influence of the 2015–16 El Niño was initially tempered somewhat by very warm temperatures in the Indian Ocean. From April to August, above-average rainfall fell over parts of inland Western Australia, New South Wales and eastern Victoria.

But by spring, the Indian Ocean was helping El Niño, resulting in Australia’s third-driest spring on record, limiting growth at the end of the cropping season. A record early heatwave in October further reduced crop production in the Murray-Darling Basin.

The northern wet season produced a record-low three tropical cyclones in the Australian region. The previous record was five, which happened in 1987–88 and again in 2006–07 – both El Niño years.

Fewer clouds and less tropical rain contributed to the most severe coral bleaching event on record for the Great Barrier Reef.

The combination of heat and low rainfall brought a very early start to the fire season, with more than 70 fires burning in Victoria and around 55 fires in Tasmania during October. Dry conditions in Tasmania also resulted in hundreds of fires being started by dry lightning in mid-January 2016. The fires damaged large areas of the Tasmanian Wilderness World Heritage Area, including areas of rainforest and bogs, which may not have seen fire for centuries.

May 2016 Climate Summary


The last month of autumn brought some surprises in the form of unusual weather for the time of year with temperatures ranging from 4ºC on the 30th to 27ºC on the 10th   On five days we were below ten degrees. The mean temperature for the month was  18 degrees, representing  three degrees below the average for May.

For most of the month our weather was the result of a synoptic pattern of high pressure system covering the whole country  and a series  of intensive low pressure troughs   moving through The Bight  and lower Tasman Sea.’

Rainfall for the month is 56mm, well below the 120 year norm of 139mm. It rained on ten days. The highest recorded was in 1903 with 611mm, and the lowest in 1927 with 3.0mm.

There were 142 Bright Sun hours and 93mm of evapotranspiration

El Niño ends with the tropical Pacific Ocean returning to a neutral El Niño–Southern Oscillation (ENSO) state. Sea surface temperatures across the tropical Pacific have cooled to neutral levels, supported by much cooler-than-average waters beneath the surface. International climate models indicate the tropical Pacific Ocean will continue to cool, with six of eight models suggesting La Niña is likely to form during the austral winter (June–August) with 50% of it happening

East Coast Low Pressure Trough Line

New Picture (2)

East Coast Low update 5.6.2016 at 9.00am

The East Coast Low did not behave like an East Coast Bomb as the low pressure trough moved out of area and down into NSW at a faster rate than expected. Storm rainfall from the system as it passed over the Ranges was 117mm and wind gusts peaked at 45 km/hr at 4.00am Saturday

A satellite image of the current position of the low pressure trough  line is shown in the map above


Latest Synoptic Situation

.Synoptic Situation: Issued by The Bureau of Meteorology at 5:01 am Saturday, 4 June 2016

A strong upper trough over the southern interior of Queensland will shift east into southeast Queensland today, before moving off the southern coast during Sunday.

A surface trough is deepening near the Capricornia or Wide Bay coast, with a low pressure system possibly developing and slipping southwards over southern Queensland waters during the day and most likely moving offshore or into New South Wales late Saturday.

A moist easterly wind flow to the south of the surface trough is expected to combine with the upper feature to generate heavy rain, which may lead to flash flooding, over areas southeast of about Hervey Bay to Toowoomba to Warwick today. 24 hour totals of 30 to 150mm are likely over inland parts, with falls in excess of 250mm possible nearer to the coast and ranges.

The heavy rain areas should start contracting southeast during Saturday morning as the trough shifts southwards, easing around Brisbane from mid-afternoon, and easing around the Gold Coast during Saturday evening.

Damaging winds, with peak gusts of around 90km/h, are possible in coastal areas and about the Scenic Rim near and south of the surface trough today.

The trough or low will also generate large swells as it slips southwards during Saturday, with dangerous surf conditions and significant beach erosion developing about exposed beaches between Fraser Island and the Gold Coast during Saturday morning, easing slightly over the Fraser Coast and Sunshine Coast waters during Saturday afternoon.


Forecast Saturday 4th June

Forecast Saturday 4th June

Sunshine Coast area

Cloudy. Very high (95%) chance of rain, most likely in the morning, and easing in the afternoon. The chance of a thunderstorm in the morning and afternoon. Heavy falls possible. Winds northeasterly 15 to 25 km/h increasing to 25 to 35 km/h in the morning then shifting westerly 15 to 20 km/h in the late afternoon.

Dangerous surf conditions will tend large and powerful during the afternoon, and are expected to be hazardous for coastal activities such as rock fishing, swimming and surfing.

Area of Severe Weather Warning

Map 3.6.16