Sometimes the past holds clues to the future, the weather patterns ebb and flow and generally do follow a cycle. Currently we are coming off the back of one of the coldest,harshest and driest winters for many a year. When I was farming in Zimbabwe, the El Nino/La Nina effect was fairly well known and we tried to plan accordingly where we were within the 5-7 year cycle. It is interesting note that warm wet southern hemisphere years correspond with hot dry northern hemisphere years during these cycles. So here are some stats from '75/'76 to jog the memory and for those that cannot remember, or weren't around then, bring you up to speed on what transpired.
1975/1976 (two-year drought):
1. The famous DROUGHT of 1975/76 was memorable for its severity over most of the British Isles, and also for its exceptional persistence. It produced the highest values for a drought index for south-east England in three hundred years. Not since 1749/50 had a period from one summer to the following spring been so dry in southern Britain. At Oxford, every month from May 1975 to August 1976 had below average rainfall with the sole exception of September 1975. It was the DRIEST 16-month period on record for England and Wales. The severity of the drought was highlighted by the acute hydrological impact of an exceptionally dry winter being sandwiched between two hot, dry summers. The drought was most severe in south-eastern England but was felt widely across England and Wales, and the most stringent water supply restrictions were experienced in South Wales, where water was cut off for up to 17 hours a day to domestic consumers. North-west England and much of western Scotland escaped the attentions of this notable drought and were more frequently subject to the passage of fronts associated with cyclonic systems displaced northwards by the high pressure over southern England.
1976 (January):
1. The GALE late on the 2nd (into the 3rd) in 1976 was one of the most severe to affect the British Isles in the twentieth century. Wittering (Cambridgeshire) in the east of England recorded a GUST of 91 knots at 2218 GMT on the 2nd and many stations across the NE of England, East Anglia and the Midlands experienced GUSTS in excess of 70 knots, with mean winds (hourly) 45 knots or more. Strong Gale or storm force was often reached with HURRICANE force 12 reported from some places in South Wales, southwest and northern England. Widespread damage and deaths (23 deaths noted at the time). A caravan site near Doncaster was destroyed. Some FLOODING on the North Sea coast: 4 feet (circa 1.2 m) of flood water in Mablethorpe and Sutton-on-Sea (Lincolnshire). DAMAGE was noted in almost every county of England, Wales & Northern Ireland. There were prolonged power cuts in widely separated areas. Railway services were badly affected in the Midlands because of the collapse of overhead power supplies. At Southend airport, a light aircraft was bodily lifted from the tarmac and thrown onto an adjacent railway line, where it burst into flames and blocked the railway services into London. [HS/23]
1976 (Spring):
1. Less than 50% of normal RAINFALL in the south-east of England during spring: contributing to the ensuing problems during the SUMMER DROUGHT.
1976 (June/July):
1. No previous HEAT WAVE in Britain, nor any since, has ever come close to the duration of the late June/early July 1976 HOT SPELL. From the 22nd June to 16th July, the temperature reached 80 degF daily. Even more remarkable, from 23rd June to 7th July, a period of 15 consecutive days, the temperature exceeded 32 degC somewhere or other in the country.
1976 (May75 - Apr76):
1. For England and Wales, the 12 month period May 1975 to April 1976 was the DRIEST 12 month period since the series began (?EWR) in 1727.
1976 (Summer):
1. It was easily the DRIEST, SUNNIEST and WARMEST summer (June/July/August) in the 20th century (at this date, but see 1995 - which is now regarded as the driest). Only a few places registered more than half their average summer rainfall. In the CET record, it was the WARMEST summer in that series.
2. It was the WARMEST summer in the Aberdeen area since at least 1864.
3. It was the DRIEST summer since 1868 in Glasgow.
4. Probably the HOTTEST summer for over three centuries. CET values were (with anomalies rel. to 1961-90 averages): Jun:17.0(+2.8), Jul:18.7(+2.6), Aug: 17.6(+1.8). In particular, for the period mid-June to mid-July, 1976, this was one (of two, the other being in 1826), WARMEST 30-day periods in the CET series, with a value of 19.7degC.
1976 (September+October):
1. For England and Wales as a whole (EWR), it was the WETTEST such spell in the entire record ... back to 1727. The combined EWP value for September & October=305mm. (Since 1727, the rainfall of September 1976 is 10th wettest in the series.) [ The wettest September + October totals since 1727 were during 1903 (310mm), 1841 (295mm) and 1960 (290mm), therefore the total for 1976 (September+ October) at 305mm is close to a record. ]
1976 (Autumn):
1. A notably VERY WET autumn for all areas ( except for north and west Scotland.) In some parts of northern England, and the extreme south, 200% of average rainfall was recorded. [ Coming after the notably dry spring/summer of course ] Information taken from here: http://alturl.com/x7kf9
Now let's look at the current situation, courtesy of Bryce Anderson from DTN/The Progressive Farmer website, the link to which is on the right hand side bar of my page.
The development of that northern high pressure block is still to be determined; however, La Nina is definitely around and, in fact has reached some historic levels. The Australia Bureau of Meteorology announced recently that its records of the Southern Oscillation Index (SOI)--the barometric pressure component of El Nino/La Nina which tracks the comparison between Tahiti and Darwin--had an average value of +21.1 between August and December 2010. That average is the second-highest Aug-Dec value on record--second only to the La Nina of 1917-18, which had a value of +24.4. But--more to the point in terms of crop concerns--the current La Nina moved past the La Nina of 1975-76, which had a reading from August through December of +18.8.
Now, here's where it gets interesting if you're looking for comparisons. I checked with our contributing analyst Joel Karlin of Western Milling for some corn yields for 1976--and found out--as I thought--that '76 was a real have and have-not year in the Corn Belt.
Here are the numbers. The U.S. national yield declined by 4.2 percent. And in some selected states, Joel sent these yield figures: Eastern Corn Belt states were above trendline for the year, with Illinois +2.1 pct; Indiana +10.4 pct; Ohio +7.6 pct; and Kentucky +23.3 pct.
But, the Western Corn Belt had a much different story: Iowa's yield was down by 11.4 pct; Nebraska down 10.6 pct; and Missouri down 22.3 pct. I don't have yield information for other states west of the Mississippi, but after talking with producers in Sioux Falls about the 1976 season I have no doubt that such declines in yield were similar or even greater.
Now, 1976 was an entire generation ago, and corn production is far, far more advanced. This account is also a look at just one of many parts in the production scenario. Still--the strength of this La Nina bolsters ideas that its influence will be around through at least the first half of the 2011 season--and we will not discount its presence as we approach the end of winter.
So where does that leave us here in the south west? Well, I am not counting my chickens, however my advice is get all land prep done earlier, consolidate moisture in seedbeds and plant early, don't wait for a calender date. Don't ladel nitrogen on, as this will encourage rank vegetative growth which will exaccerbate moisture stress, conserve every blade of grass you can if a livestock farmer and hope like hell we have rain at critical growth stages to see crops through.
Positive Weather Solutions are currently saying it will be a drier, earlier spring too so lets pray that September and October don't produce swamp conditions and make establishing next years(2012) crop hard work. Here is their current outlook. Take note, given they got last year pretty much right, as well as forecast a very cold winter last year and the year before..... http://alturl.com/cwmce
