2.5 Significant Eras in the Development of Operational Long-Range Weather Prediction

Monday, 8 January 2018: 11:30 AM
Room 2 (ACC) (Austin, Texas)
Robert William Reeves, NWS, Silver Spring, MD

Significant Eras in the Development of Operational Long-Range Weather Prediction

In February 1870, President Grant signed into law a bill authorizing the Secretary of War to take weather observations at military stations and to warn of storms in the Great Lakes and the Atlantic and Gulf Coasts. Thus was born in the Army Signal Service The Division of Telegrams and Reports for the Benefit of Commerce, eventually to become the Weather Bureau.

Routine weather forecasting was “off and running” and has continued apace since then. But when did the Service “break out” from the strict protocol of issuing 24-hour forecasts to consider extensions into the future? Most would agree that the “modern” era in long-range prediction (L-RP) began with the ground-breaking efforts of Jerome Namias at MIT in the late 1930s. However, from the agency’s earliest days, there was both self-imposed internal pressure by ambitious and/or creative forecasters and external pressure by the public sector to produce long-range predictions.

We recount events and highlight personalities that significantly impacted (L-RP) process. We have chosen two important periods to highlight the often-complex process behind the furthering of prediction science. The first period begins with the agency’s earliest attempts to extend the forecast in the late 1800s up to the mid 1930s and the availability of funds to pursue (L-RP).

The second period covers the 1970s and the creation of a national climate program and the renewed interest in prediction. A variety of factors, including a major El Nino and international politics “conspired” to “rescue” (L-RP).

The administration did not buckle under the pressure to produce long-range predictions and was reluctant for many years to allow their forecasters to experiment beyond the basic 24-hour prediction. Preserving the scientific integrity was of the utmost importance in the mind of the agency’s management.

From the Weather Bureau’s earliest days its principal scientist, Cleveland Abbe, exerted important influence. Prior to his appointment with the new agency, Abbe was with the Cincinnati Observatory, where in 1869 he even attempted what he referred to as his “first long-range forecast,” a 3-day outlook for Cincinnati for September 22 – 24 based upon surface reports from only 10 stations!

He published an article in the MWR in 1901 entitled “The physical basis of long-range weather forecasts.” Abbe laid out the governing equations that would allow prediction of future states of the atmosphere from initial data. Abbe realized that solving the set of governing equations would require surface and upper air data, and he suggested various techniques, including numerical, for solving them. He was not optimistic that the challenge of long-range prediction would be met in his generation.

A flood of private forecasters entered the field at the turn of the century, not all of them reputable. Willis Moore, Chief of the Weather Bureau from 1885 to 1913, opposed these “charlatans” with some harsh language, and the agency resisted all non-scientific methods to extend the forecast. The prevailing view was that the key to extension lay in expanding the observational arrays toward the north and west. Through the 1920s and 1930s, the Weather Bureau continued its policy of discouraging “non-scientific” prediction efforts.

Several decades later, beginning in 1972, a number of factors conspired to alter the course of long-range prediction, starting with a meeting of glaciologists in Providence, R.I. in January. One of the results of the meeting was that a cooling of the earth may be imminent. Organizers George Kukla of the Czechoslovakian Academy of Sciences and Robert Matthews of Brown University wrote to President Nixon, warning that the cooling was a real possibility. The White House forwarded the letter to the State Department since it had cold war implications. An ad hoc panel was convened for review and appropriate action, with international politics, environmental events, and global markets contributing to the deliberations. The climate interests in the federal agencies saw this as an opportunity to propose a national climate program.

The1972/73 El Niño fortuitously appeared, and linkages were made to several, high-impact events, such as the killing winter freeze followed by summer heat wave; drought in the Soviet Union producing 12% shortfall in their grain production in 1972, forcing the country to purchase grain abroad which in turn reduced world grain reserves and helped drive up food prices; collapse of the Peruvian anchovy harvest, impacting world supplies of fertilizer, the soybean market, and prices of other protein feed stocks; and anomalously low precipitation in the Pacific Northwest 1972/73 winter, seriously depleting water reservoir storage. Long-range prediction was now a priority

By the mid-1970s negotiations were underway to establish a national climate program which would include a long-range forecast function. The National Climate Program was signed into law in 1978. The rescue of the enterprise was now complete, and prediction had secured its place in the new National Weather Service Climate Analysis Center.

What started as a somewhat histrionic letter to the White House warning of the coming ice age, concurrent with a major El Niño and related devastating weather effects across the globe, with attendant economic implications and cold war repercussions (Soviets bought American grain at bargain prices), ended with the implementation of an important national plan to address climate issues and gave renewed emphasis to (L-RP).

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