The U.S. Weather Service knew on Wednesday or before that Thursday’s temperatures would reach the 50-degree mark, an unusually warm temperature three days before Christmas when over a 30-year period temperatures usually have been near or below freezing.

At Bangor International Airport the temperature reached 53 degrees Thursday.

A year ago, as Christmas approached, highs climbed to the 40s on Dec. 20 in Bangor and Eastport. On Dec. 21, a severe rainstorm swept all of Maine, resulting in one traffic fatality, as temperatures reached 53 in Bangor, 35 in Caribou and 46 in Easport. By Dec. 23, highs sunk to a seasonal 26 degrees in Bangor and 13 in Caribou.

The Old Farmer’s Almanac, printed in Dublin, N.H., was correct in predicting sudden and violent temperature changes in December, but missed the very mild temperatures this Dec. 22, predicting generally cold weather through Dec. 26, and sunny and mild temperatures for Dec. 27 and 28.

The Farmers’ Almanac, printed in Lewiston, Maine, did not predict any particularly high temperatures for New England during December.

But it did mention showers and mild temperatures in New York, Pennsylvania and Virginia Dec. 17-20, showers Dec. 21-24, and warmer temperatures toward the end of the month in southern New England.

The two weather almanacs provide predictions a year at a time. They are legendary for their accuracy and each uses a secret formula.

The Old Farmer’s Almanac says at the beginning of its weather section that it combines a secret formula with “the most modern scientific calculations based on solar activity.”

But, the writer says, “… neither we nor anyone else has as yet gained sufficient insight into the mysteries of the universe to predict weather with anything resembling total accuracy.”

The Old Farmer’s Almanac predicts slightly above-average winter temperatures and snowfall for 1995, wild weather variations from one area to another through the United States, and that some snowy and cold conditions will persist into the spring of 1995.

Sondra Duncan, managing editor of the Farmers’ Almanac in Lewiston, commented that if weather predictions were entirely accurate, Maine people would lose one of their favorite conversation topics.

At the Portland office of the National Weather Service this Thursday, a recording warned of rather frightening storms in the Gulf of Maine.

In a straightforward county-by-county roundup of winds and temperatures, the National Weather Service cautioned people at sea, then forecaster Michael Fitzsimmons came on the line to provide some more personal insights.

Fitzsimmons said that the weather service produces two kinds of reports, one of a period of several days, the other a three-month prediction. The service is available to the public and is used by print, radio and television weather forecasters.

The period of December through February will bring below-normal precipitation, Fitzsimmons said. How does he know? The Portland office only sends out information. “We get the final product, but we don’t do the number crunching in this office. That’s the Climate Analysis Center in Camp Springs, Maryland.”

If a 48-hour forecast is off, it is only by timing, not content, Fitzsimmons said. He agreed that predicting weather is a frustrating occupation where changes often come hourly, but the science has “grown at a pace as fast as that of the medical profession.”

At the Climate Analysis Center in Camp Springs, meteorologist Russell Martin works with computer models of weather patterns to make predictions over six- to 10-day periods.

Longer predictions are possible using comparisons of ocean surface temperatures and the upper atmosphere, Martin said. Getting into seasonal, even yearlong predictions requires use of historic data and very general predictions based on the probability of climatic conditions, the meteorologist said.

As for predictions made by almanacs for specific days, “it simply can’t be done,” Martin said. “If you look at the forecasts, they are no better than random guessing.” He said the high success claimed by some almanacs is because they are so vague “it’s like saying it will be cold sometime this winter.”

The weather service predicts mild temperatures and rain will prevail through Monday in Maine. Lows will be in the low 30s north to mid-30s south; highs will be in the 30s north and 40s south through the weekend.

Our forecast? Keep a warm coat and an umbrella handy.