Analog Forecasts

Analog forecasts compare the evolution of current atmospheric conditions to past years where users may have personal experience to draw from.

pilot on sea ice with submarine
A submarine in the sea ice during the 2020 ICEX. The U.S. Navy's ICEX, or Ice Exercise, is a biennial exercise conducted above the Arctic Circle in cooperation with other branches of the military, government agencies, allied partners, private organizations, and academic institutions.
ICEX provides submarines the opportunity to train in an operationally demanding and challenging environment, as well as an opportunity for scientific studies on ice thickness and the environment. Visit the ICEX website
Photo: United States Navy
model of sea ice forecasting
Observed sea level pressure (top, March 2018) compared to EAPI-forecasted conditions (bottom), each showing a strong high pressure center above Alaska that produced strong winds. This forecast was shared with the US Navy during the 2018 ICEX submarine exercise.

On-the-ground experience is an excellent starting point for decisive action

We have developed a new forecasting technique at the nexus of science and experience-based decision-making. The analog forecasting technique examines forecasts that are days, months, or a year into the future and looks for a time in the past when the weather scenario looked very similar (an analog).

Analog forecasting has many applications

From wildfire management to storm readiness, analog forecasting is useful anytime people can benefit from knowing when today’s conditions are similar to a time in the past.

The United States Navy taps into past experience

Our team provides daily analog forecasts to the U.S. Navy during their biannual ice exercises, known as ICEX, in the Arctic Ocean. The forecasts aim to provide advance notice of potential ice and weather hazards that could impact under-ice submarine activity or the temporary ice camp housing support staff.

To supply the forecasts, sea ice and atmospheric conditions that led to past hazards are analyzed. For example, a crack in the ice damaged a runway that had been used in a previous exercise. The forecast team analyzed the air pressure driving the winds that moved and cracked the ice. Forecasters search for developing atmospheric conditions that are similar. When matches arise, Navy personnel apply their experience responding to past hazards to make faster, safer decisions about the future.

A tool to streamline analog forecasting

To streamline analog forecasting, EAPI and the Scenarios Network for Alaska + Arctic Planning produced a web tool to identify best analogs back to 1949 for six atmospheric variables, including precipitation and sea level pressure. The tool then provides a forecast based on how the weather patterns evolved in those analog years.

Users specify the areas from which the analogs are determined, such as the tropics, where ocean temperatures and pressures can correlate with future weather in Alaska. The tool is designed for forecasting professionals and others with experience using climate data for planning.

Download a PDF about this project

Project Leads

Professor John Walsh is the director of the Center for Global Change & Arctic System Research and the Cooperative Institute for Alaska Research. He's also a President's Professor of Climate Change and Chief Scientist for UAF's International Arctic Research Center.

John Walsh, Chief Scientist, UAF International Arctic Research Center


Hajo Eicken

Hajo Eicken, Director, UAF International Arctic Research Center