Kevin Irvine's Long Range Weather Forecasts
Contact; David Clarke
"Long-range weather forecasts" are periodically broadcast on Australian Broadcasting Corporation (ABC) radio in South Australia. I decided to investigate the reliability of these forecasts; my conclusion - they are as good as deciding whether it's going to rain by the toss of a coin. I was surprised and disappointed to find out that the ABC makes no effort to check whether there is some correlation between the forecasts and the weather. I suspect that many listeners would assume the forecasts do show some similarity to the weather simply because they are broadcast by a (generally) reputable broadcaster. It must be stressed that what is being discussed here is not the long-term outlooks released by the Australian Bureau of Meteorology based on such things as the Southern Oscillation Index. I have no reason to doubt the scientific basis of Bureau forecasts.
The table below gives both the forecast weather and the weather that the Bureau and I recorded. I believe that the reader will see that there is very little that the two have in common. Note that one period when the forecaster got it fairly right (June 5-10th), was when he could have listened to the Bureau's forecast (generally for four days ahead). I recorded the forecasts and weather for the period 13th April to 6th July, and the whole of the record is given below. I suppose the moral is, let the buyer beware (caveat emptor). |
Date | Forecast | Actual weather | Comments |
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The forecaster generally forecast only the rainy periods, he didn't usually mention the dry periods; hence, where no entry below, take as fine. | I have tried to record the days when the rain actually fell, rather than when it was tipped out of the rain gauges. All the observations below have been checked against Australian Meteorological Bureau data, and some notes are from M.B. publications. | ||
13-Apr-01 | Fine | ||
14-Apr-01 | Weak change | Fine | |
15-Apr-01 | Fine | Fine | |
16-Apr-01 | Fine | Fine | |
17-Apr-01 | Fine | ||
18-Apr-01 | Fine | ||
19-Apr-01 | Rain coming | Fine | |
20-Apr-01 | General rain | Fine | |
21-Apr-01 | General rain | Fine | |
22-Apr-01 | General rain | Light rains a few places in SA | |
23-Apr-01 | General rain | Fine | |
24-Apr-01 | Clearing | Fine | |
25-Apr-01 | Clear | Fine | |
26-Apr-01 | Fine | ||
27-Apr-01 | Showers in some areas | ||
28-Apr-01 | Fine | ||
29-Apr-01 | Fine | ||
30-Apr-01 | Fine | ||
1-May-01 | Fine | ||
2-May-01 | Fine | ||
3-May-01 | Scattered showers | ||
4-May-01 | Scattered showers | ||
5-May-01 | Fine | The day of the monthly long-range forecast | |
6-May-01 | Fine | ||
7-May-01 | Fine | ||
8-May-01 | Fine | ||
9-May-01 | Rain Whyalla & Victor Harbor, little elsewhere | ||
10-May-01 | Fine | ||
11-May-01 | Showers | Fine | |
12-May-01 | Showers | Fine | |
13-May-01 | Showers | Fine | |
14-May-01 | Showers, some rain | ||
15-May-01 | Rain some places (incl. Adelaide) | ||
16-May-01 | Some rain Maitland, Naracoorte, little elsewhere | ||
17-May-01 | Good rains Adelaide, Vic. Harbor, Clare (4mm at Crystal Brook) | ||
18-May-01 | Rain | Rain | |
19-May-01 | Rain | Some showers | |
20-May-01 | Rain | Fine | |
21-May-01 | Wet | Fine | |
22-May-01 | Fine | ||
23-May-01 | Fine | ||
24-May-01 | Fine | ||
25-May-01 | Fine | ||
26-May-01 | General rains | ||
27-May-01 | General rains | ||
28-May-01 | General rains | ||
29-May-01 | Fine | ||
30-May-01 | Fine | ||
31-May-01 | Fine | ||
1-Jun-01 | A little rain in Adelaide? | ||
2-Jun-01 | Fine | The day of the monthly long-range forecast | |
3-Jun-01 | Fine | ||
4-Jun-01 | Fine | ||
5-Jun-01 | Showers | General rains throughout the | In May the original forecast was for rain 7-9/6 but changed |
6-Jun-01 | Showers | state from about 5th to 10th | to 5-9/6 in his forecast on 2/6. Listened to |
7-Jun-01 | Showers | Rain | the Bureau forecast? |
8-Jun-01 | Showers | Rain | |
9-Jun-01 | Showers | Rain | |
10-Jun-01 | Rain | ||
11-Jun-01 | Rain | ||
12-Jun-01 | Rain | ||
13-Jun-01 | Rain | ||
14-Jun-01 | Mainly fine | ||
15-Jun-01 | Fine | ||
16-Jun-01 | Good rains to 21st | Fine | |
17-Jun-01 | Rains | Fine | |
18-Jun-01 | Rains | Fine | |
19-Jun-01 | Rains | Fine | |
20-Jun-01 | Rains | A few showers | |
21-Jun-01 | Rains | A few showers | |
22-Jun-01 | A few showers | ||
23-Jun-01 | Fine | ||
24-Jun-01 | Fine | ||
25-Jun-01 | Fine | ||
26-Jun-01 | Fine | ||
27-Jun-01 | Fine | ||
28-Jun-01 | Fine | ||
29-Jun-01 | Fine | ||
30-Jun-01 | Fine | ||
1-Jul-01 | Fine | ||
2-Jul-01 | Fine | ||
3-Jul-01 | Fine | ||
4-Jul-01 | Rain | ||
5-Jul-01 | Rain | ||
6-Jul-01 | Some showers |
I have quoted the predictions as soon as I read them and before the time of the predicted events. I later recorded the actual weather. I have not selectively picked predictions that were either right or wrong.
Prediction broadcast on (date) | Date of predicted weather | K. Irvine's forecast | Outcome | |||||||||||||||||||||||||||||||||||||||||||||
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April 3rd | Second week of May | "The opening of the season should come in the second week of May just before the Adelaide Cup. Further rain is due in late May and early June." | Rain just sufficient to be called opening fell in at least the Clare area in late April. My information is that the Mount Lofty Ranges had opening rains before the end of April. | |||||||||||||||||||||||||||||||||||||||||||||
April 3rd | July | "July will be the best month of the year for rains with falls due in the first and fourth weeks of the month" | ||||||||||||||||||||||||||||||||||||||||||||||
April 3rd | August | "August will see average rain" | ||||||||||||||||||||||||||||||||||||||||||||||
April 3rd | Winter | "The winter months are looking good for rain" | ||||||||||||||||||||||||||||||||||||||||||||||
Prediction broadcast on (date) | Date of predicted weather | K. Irvine's forecast | Outcome | |||||||||||||||||||||||||||||||||||||||||||||
May 1st | Second and third week of May | "There will be rain in the second week of May just before the Adelaide Cup with further rain in the third week of the month, providing an opening to the season." |
My impression is that opening rains did not fall in most cereal growing
areas of the state in May.
Rain recorded at Crystal Brook for May:
DKC: my rain guage PO: Post office Note: PO rain guages are not normally read on weekends, and I did not check my rain guage every day. | |||||||||||||||||||||||||||||||||||||||||||||
May 1st | June | "Good winter rains will arrive in the first week of June and farmers inland may need this to boost their opening to the season." | ||||||||||||||||||||||||||||||||||||||||||||||
May 1st | July | "July will be the best month for rain with falls in the first
and fourth weeks."
Compare this with the July forecast given in June (DKC) | ||||||||||||||||||||||||||||||||||||||||||||||
May 1st | August to October | "Average rains are forecast through August, September and early October providing an average to good season for farmers." | ||||||||||||||||||||||||||||||||||||||||||||||
Rainfall map for May from Bureau of Meteorology | ||||||||||||||||||||||||||||||||||||||||||||||||
Prediction broadcast on (date) | Date of predicted weather | K. Irvine's forecast | Outcome | |||||||||||||||||||||||||||||||||||||||||||||
June 5th | June | "More rain in the middle of June" |
Rain recorded at Crystal Brook for June:
DKC: my rain guage PO: Post office I would think that most Crystal Brook locals would consider the rain of 2nd June to be the opening rain for the season.
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June 5th | July | "July will be a good month for rain with falls in late June/early
July followed by more rain in the middle of July"
Compare this with the July forecast given in May (DKC) | ||||||||||||||||||||||||||||||||||||||||||||||
June 5th | Remainder of year | "Kevin says there won't be any big rains this year and is expecting the predicted showers to provide falls of between 10 and 20 mm each time." | ||||||||||||||||||||||||||||||||||||||||||||||
Rainfall map for June from Bureau of Meteorology | ||||||||||||||||||||||||||||||||||||||||||||||||
Prediction broadcast on (date) | Date of predicted weather | K. Irvine's forecast | Outcome | |||||||||||||||||||||||||||||||||||||||||||||
July 3rd | First weeks of July | Kevin talked about rain over the next few weeks. His prediction was unspecific and could partly have been taken from 7 or 10-day forecasts available on the Internet. |
Rain recorded at Crystal Brook for July:
DKC: my rain guage PO: Post office Note: PO rain guages are not normally read on weekends, and I did not check my rain guage every day. | |||||||||||||||||||||||||||||||||||||||||||||
July 3rd | Mid to late July | "There'll be further rain in the middle of July and in the fourth week of the month." | ||||||||||||||||||||||||||||||||||||||||||||||
July 3rd | August | "Kevin also says to expect rain in the first week of August." | ||||||||||||||||||||||||||||||||||||||||||||||
July 3rd | September & October | "The spring rains will start in early September and continue through to October which will result in an average season for farmers. Some areas that had their crops in earlier should finish with better than average crops." | ||||||||||||||||||||||||||||||||||||||||||||||
July 3rd | November | "The spring rains will come to an end in early November..." | ||||||||||||||||||||||||||||||||||||||||||||||
July 3rd | Summer | "December will be a reasonable month for temperatures but look out in January and February because Kevin says it's going to be HOT!" |
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Above is the rainfall map for July from Bureau of Meteorology |
Rainfall recorded at Crystal Brook in July DKC: my rain guage PO: Post office
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Above is the rainfall map for August from Bureau of Meteorology |
Rainfall recorded at Crystal Brook in August DKC: my rain guage PO: Post office
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Above is the rainfall map for September from Bureau of Meteorology |
Rainfall recorded at Crystal Brook PO in September
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Above is the rainfall map for October from Bureau of Meteorology |
Rainfall recorded at Crystal Brook PO in October
DKC: my rain guage PO: Post office
This month was a disaster for cereal farmers. Mr. Irvine seems not to have foreseen it at all. |