Back to one 9-day ECMWF model loop this week.
With the exception of the Atherton Tableland (Qld) and some coastal areas, not much to report.
Keep an eye on https://meteologix.com/au for more site-specific analysis.
Image loop courtesy Meteologix
With the climate models refreshing their monthly outputs this week, Jon and Janine talk through likely scenarios and main influences this calendar year, relevant climate research relating to grain markets and discuss implications for livestock and broadacre cropping industries.
To access the 20-minute recording, click on the image below!: 👉
This is last heat wave plot for the year! Unlike other years, no story here for anywhere in Australia.
About heat waves
Heatwaves are calculated using the forecast maximum and minimum temperatures over the next three days, comparing this to actual temperatures over the previous thirty days, and then comparing these same three days to the 'normal' temperatures expected for that particular location. Using this calculation takes into account people's ability to adapt to the heat. For example, the same high temperature will be felt differently by residents in Moree compared to those in Orange, who are not used to the higher range of temperatures experienced in Moree. The full forecast can be accessed here: http://www.bom.gov.au/australia/heatwave/
This is pretty rare. Water vapour levels are in the extreme range basically all week. The image below shows a concentration of water vapour over central-eastern Australia for the period Sunday through Wednesday.
The water vapor content of the atmosphere is of critical importance to nearly every facet of atmospheric science. Observing the processes that determine the water vapor content of the atmosphere is, therefore, of fundamental importance. As the earth’s surface is the source of most atmospheric water vapor, observations of vertical turbulent transport of water vapor in the planetary boundary layer have been the subject of many research projects. Evapotranspiration can vary significantly across the earth’s surface due, for example, to variability in insolation, vegetation cover, soil properties, and precipitation. Area-averaged water vapor flux measurements are necessary to get a large-scale view of surface–atmosphere interactions.
The Extreme Forecasting Index (EFI) is an integral measure of the difference between the ensemble forecast (ENS) distribution and the model climate (M-climate) distribution. This allows the abnormality of the forecast weather situation to be assessed without defining specific (space- and time-dependant) thresholds. The EFI takes values from -1 to +1. If all the ensemble members forecast values above the M-climate maximum, EFI = +1; if they all forecast values below the M-climate minimum, EFI = -1. Experience suggests that EFI magnitudes of 0.5 - 0.8 (irrespective of sign) can be generally regarded as signifying that "unusual" weather is likely whilst magnitudes above 0.8 usually signify that "very unusual" weather is likely. Although larger EFI values indicate that an extreme event is more likely, the values do not represent probabilities as such.
Two leading models this week: 9-day ECMWF and NCEP 15-day loop.
Some serious rainfall activity predicted for parts of Australia’s NW and eastern areas.
A sneak peek at the updated multi-week models just now shows the BOM model going extreme wet ‘till mid-April, JMA showing slightly above average and the IRI model much more cautious with a focus on rain events for inland NSW, Qld channel country and the Gulf for the next 3 weeks.
Updated SSTs show waters warming to Australia’s north and the Coral Sea continues to warm up, which is encouraging.
Keep an eye on https://meteologix.com/au for more site-specific analysis.
Image loop courtesy Meteologix
The MJO is showing a weak pulse in Phase 1 in the African region, however, the guidance suggests it’s unlikely to influence our climate for the next fortnight.
The next 3 weeks could see some game-changing rainfall events, with all multi-week models showing broad consensus for rainfall across eastern Australia.
The long term situation looks more nuanced in 2021. ENSO is heading towards neutral, as is the IOD. However, the Modoki index maybe the climate story of 2021.
Some tropical cyclone activity in the northwestern tropics and possibly the Gulf of Carpentaria in the coming fortnight, with FN Qld gaining a reprieve from recent wetter conditions.
The chart above shows lower air pressure pretty much over the entire continent. The large area of low pressure makes the MJO virtually indiscernible.
Some excellent falls in Southern Qld catchments overnight - that badly needed rain. Click on the link for an updated map. http://www.bom.gov.au/australia/flood/?ref=ftr
Weekly rain shows some fantastic falls across the tropics, Central Qld and parts of eastern Australia. March looks like it could be wetter than February.
Australian 7-day rainfall map courtesy http://www.bom.gov.au/climate/maps/rainfall/?variable=rainfall&map=totals&period=week®ion=nat&year=2020&month=12&day=17
Model commentary: IRI model has a wet tone so that in itself is an achievement. It hasn’t been excited by anything much since the December rain. It is favouring more rain across NSW than Qld, whereas the BOM model is more aligned with the 9-15 day ‘weather’ models showing Qld as the main beneficiary of decent 100-200mm+ totals. JMA, who has been the form horse of the campaign, favours rain events throughout the next 4 weeks in a general sense across the eastern half of Australia. The ACCESS-S model did a very poor job over Qld this summer, so let’s hope the current “80% chance” for rain over most of that state is not a poison chalice. Keep an eye on the Meteologix 10 day Forecast XL for a full summary of all ‘weather models’ as events draw closer for your area: https://meteologix.com/au
The chart below shows a weak pulse of the MJO in Phase 1 over Africa. Models are anticipating the MJO to run out of steam and go back into its shell. It is essentially buried among the broad-scale La Nina pattern still at play, making it difficult to track. Nothing much to see here.
The Madden – Julian Oscillation (MJO) is a tropical disturbance that moves eastward around the global tropics every 30-60 days and has proven to influence rainfall and temperature conditions. The strength of the MJO may increase or decrease as it progresses eastwards, affecting the level of convection and influence on both precipitation and temperature. The diagram below is used by scientists to track the path of the MJO showing predicted dates through various phases (see December MJO explainer). A short YouTube cartoon explaining the MJO can be found here
(from U.S Climate Prediction Center)
NCEP TC watch is showing activity in the NW of Australia in week 1 and potential TC activity in the same region with the addition of the Gulf.
The MJO signal is weak and not near the Australian region. The outlook is a fairly general reflection of the SSTs (bottom figure) and broad-scale mean sea level pressure anomaly posted in “climate in brief”. Drier in FN Qld and more tropical activity in NW Australia and the eastern Australian mid-latitudes.
A bit drier this week, with SE Australia and most of Qld still needing moisture. Central-eastern areas and WA well set-up for winter crop 2021.
The latest IRI Enso outlook is unchanged since February (RHS). Still not a strong signal for La Niña to meet thresholds, but none-the-less El Niño still a long-shot for 2021 at this stage.
ENSO Modoki, one of the few autumn drivers statistically significant during winter crop planting, although weakening, is showing a continuation of the current wet signal. This is encouraging for much of northern Australia and the central-eastern Australian cropping belt. We need to keep an eye on this. The current signal is holding on the right side of neutral.
The Indian Ocean Dipole outlook is inherently erratic this time of year. The current JAMSTEC IOD outlook is not offering much and looks to be quite close to zero in the neutral range.
The chart above shows higher-than-normal probabilities (blue line - red arrow) of the La Niña hanging around. In the critical spring months, the board Nino3.4 indicator shows a possible La Nina return. https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-cpc_plume
The scientists at JAMSTEC developed the Modoki index. The red line is the mean of the model run. It shows this driver in neutral-wet phase through our Autumn and winter, which can do nothing but good for rainfall prospects!
Forecast chart courtesy: https://iri.columbia.edu/our-expertise/climate/forecasts/seasonal-climate-forecasts/
The prediction for extreme water vapour levels shows a concentration over the mid-latitudes over the weekend, where moisture is streaming across from NW Australia.
The water vapor content of the atmosphere is of critical importance to nearly every facet of atmospheric science. Observing the processes that determine the water vapor content of the atmosphere is, therefore, of fundamental importance. As the earth’s surface is the source of most atmospheric water vapor, observations of vertical turbulent transport of water vapor in the planetary boundary layer have been the subject of many research projects. Evapotranspiration can vary significantly across the earth’s surface due, for example, to variability in insolation, vegetation cover, soil properties, and precipitation. Area-averaged water vapor flux measurements are necessary to get a large-scale view of surface–atmosphere interactions.
The Extreme Forecasting Index (EFI) is an integral measure of the difference between the ensemble forecast (ENS) distribution and the model climate (M-climate) distribution. This allows the abnormality of the forecast weather situation to be assessed without defining specific (space- and time-dependant) thresholds. The EFI takes values from -1 to +1. If all the ensemble members forecast values above the M-climate maximum, EFI = +1; if they all forecast values below the M-climate minimum, EFI = -1. Experience suggests that EFI magnitudes of 0.5 - 0.8 (irrespective of sign) can be generally regarded as signifying that "unusual" weather is likely whilst magnitudes above 0.8 usually signify that "very unusual" weather is likely. Although larger EFI values indicate that an extreme event is more likely, the values do not represent probabilities as such.
Two leading models this week: 9-day ECMWF and NCEP 15-day loop.
Some serious activity predicted for parts of Qld previously missing out, as well as eastern NSW.
Moisture from Australia’s north-west seems to be joining up with moist air in the Coral Sea and where exactly it lands will be interesting.
A game-changing event for those who’ve been on the skinny end of a pop-gun La Nina so far this summer.
Keep an eye on https://meteologix.com/au for more site-specific analysis.
Image loop courtesy Meteologix
2020-2021 Summer season saw the La Niña signal convert to good rainfall and cooler temps in NSW, but the decile 1-2 rain in SE Qld was less telegraphed and completely missed by the majority of models. A prudent reminder that expert commentary on analogue or “like” years should remain a key part of due diligence and risk management, despite statistical methods falling out of favour among some scientists.
Reflection and key learnings: The 2020 La Niña was slow to arrive and patchy when it did. All but one GCM (US IRI) model got completely sidetracked by the warm SSTs and traditional La Niña precipitation projections. In this 2020-21 event, the atmospheric conditions were slow to align with the warm SST signal, not occurring until around mid-December. International commentators Jason Nicholls (@jnmet) and Ben Noll (@BenNollWeather) predicted the rainfall and convection to be more in-line with 1988-89 with NSW the main beneficiary (mid-panel text). The cooler-than-normal southern Coral Sea, based on research may well have reduced available convection and moisture for rainfall events and this was picked up by the IRI (US) model. This region appears to be warming up now at a rapid rate, so hopefully, those farmers get their turn this Autumn.
Very little extreme heat to trouble the scorers in the coming week through northern and eastern Australia.
About heat waves
Heatwaves are calculated using the forecast maximum and minimum temperatures over the next three days, comparing this to actual temperatures over the previous thirty days, and then comparing these same three days to the 'normal' temperatures expected for that particular location. Using this calculation takes into account people's ability to adapt to the heat. For example, the same high temperature will be felt differently by residents in Moree compared to those in Orange, who are not used to the higher range of temperatures experienced in Moree. The full forecast can be accessed here: http://www.bom.gov.au/australia/heatwave/
The European ECMWF weather model shows some serious rainfall activity through central-eastern Australia during the next 9-day period, as the Coral Sea finally warms up. The US NCEP model is even more bullish for bigger +100mm totals. A sneak peek at the refreshed multi-week models this morning shows NSW in the sweet spot for the remainder of March, with NW tropical moisture streaming down across the desert. More analysis next Friday.
Access courtesy https://meteologix.com/au
Image loop courtesy Meteologix
The MJO is showing a weak pulse in Phase 5 in the Coral Sea, however, the guidance suggests its unlikely to influence our climate for the next fortnight.
Following a wet few days in the coming weather forecast for NSW coast and ranges, March looks much more benign for regions other than the east coast and ranges.
The Autumn seasonal outlook is bullish for wetter than average conditions. Central-eastern areas appear a higher probability to receive above-normal precipitation.
Some tropical cyclone activity in the northwestern tropics and the Coral Sea anticipated in the coming fortnight, with the MJO in the Coral Sea.
The chart above shows lower air pressure pretty much over the entire continent. The large area of low pressure makes the MJO virtually indiscernible.
Some excellent falls in Central Qld catchments overnight - that badly needed rain. Click on the link for an updated map. http://www.bom.gov.au/australia/flood/?ref=ftr
Weekly rain shows some fantastic falls across the tropics and parts of eastern Australia. February is the wettest month in the calendar for many agricultural areas but many on the Downs still need more rain.
Australian 7-day rainfall map courtesy http://www.bom.gov.au/climate/maps/rainfall/?variable=rainfall&map=totals&period=week®ion=nat&year=2020&month=12&day=17
Model commentary: IRI model is back to its bland, doomsday best and is showing no excitement for rain in the coming 4 weeks. JMA, who has been the form horse of the summer, favours the coast and ranges, however, no dry signal with the exception of the far north. NCEP showing activity for the coast and ranges in the coming week, consistent with the 9-day ECMWF loop. The ACCESS-S dry February forecast from a fortnight ago was the kiss-of-death some areas needed, with up to 100mm falling across NSW this week. Keep an eye on the Meteologix 10 day Forecast XL for a full summary of all ‘weather models’ as events draw closer for your area: https://meteologix.com/au
The SAM is fairly stable in positive (wet) phase at the moment and set to continue. The SAM is theoretically coming to the end of its seasonal influence and looks unlikely to be a strong driver in the coming fortnight.
Recent research by Hendon et al, (2014) at the Centre for Australian Weather and Climate Research found the Southern Annular Mode to be the leading mode of circulation variability through parts of inland eastern Australia where cotton is grown; particularly in the spring planting period.
A positive SAM has been proven to increase moisture supply into fronts and troughs forming in eastern Australia. The chart provided by Climate Prediction Center (US) shows the most recent observations of the SAM or (AAO).
A negative SAM traditionally leads to a dry westerly circulation pattern through eastern Australian cropping areas.
BOM researchers Lim and Hendon (2013) found the SAM has the strongest connection with El-Niño Southern Oscillation in October and November – whereby the SAM is influenced most by El Niño or La Niña conditions.
Growers and advisors are encouraged to monitor the phases of the SAM together with seasonal forecasting, multi-week and short term weather models during planting. A short cartoon explaining the SAM can be found HERE.
(from U.S Climate Prediction Center)
NCEP TC watch is showing activity in the NW of Australia in week 1 and the Coral Sea region for both 7-day outlooks.
The MJO signal is weak and not near the Australian region. The outlook is for the tropical convective activity to move into the Coral Sea region, with the sea surface temps (SSTs) there finally warming up (bottom chart). The Gulf and Arafura Sea drier outlook mirrors the average/cool SSTs.
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