Use a Weather Map to Predict Waterfowl Movements
Every year brings a vast amount of new waterfowling gear, but none of these new gadgets will guarantee limits of waterfowl if you cannot use a weather map to predict waterfowl movements. The ability to read and understand a weather forecast map is just as important to your waterfowling success as your duck calls, goose calls, and decoys. You do not have to be a meteorologist to understand a weather map. Learning the basics may give you a tactical advantage for predicting waterfowl movements.
Very few events spur as much anticipation during duck and goose season as an approaching cold front. Duck and goose movements are greatly influenced by theses fall and winter weather events, but due to variations with the intensity and timing, waterfowl are affected by cold fronts in various ways. Along with cold fronts, other weather events, such as heavy rains or deep snow, may significantly stimulate the movements of ducks and geese. Heavy rains can raise water levels and create backwater areas that are easily exploited by puddle ducks. Deep snow may blanket prime feeding areas forcing geese to search out open grain fields.
In this age of technology, it is easy to follow weather trends and predict their effects on waterfowl. With all of the weather resources readily available online, waterfowl hunters do not have an excuse for weather surprises. Even if you do not have internet access, smartphone technology keeps up to date weather apps at your fingertips. Weather forecasts, including wind speed and direction, temperature, cloud cover, and precipitation, can be checked instantly. You can use the information to predict certain weather conditions. If the temperature and dew point are the same, you know there will be a high probability of fog. With the availability of weather websites, you never have to hunt facing into the wind or be caught without your rain coat.
A cold front is the transition zone where a mass of cold air is replacing a mass of warm air. A falling barometer and southerly winds are the general precursors of a cold front. As the front moves through, the winds typically change to the north. High pressure, cooler air, clear skies, and northerly winds follow cold fronts and bring favorable hunting conditions. However, not all cold fronts are equal. Early season waterfowl, including blue-wing teal, shovelers, and pintails, are stimulated to begin their migration with the first mild cold fronts of September. Widgeon and gadwalls follow around mid-October. Mallards and divers begin their migration at the beginning of November. Later waterfowl migrations follow strong cold fronts with heavy snow cover. Heavy snows in the north typically signal the end of the hunting season. Even if a cold front is mild and does not stimulate mass migrations, it will still lead to behavioral changes. Temperature has a direct effect on available food choices. If the temperature drops, waterfowl change from moist-soil foods and seeds to hotter foods, like corn, but if the weather stabilizes following the front, the birds may change back to the moist-soil foods and seeds. Food choices may change any time there is a temperature change. Even though waterfowl may migrate any time during a cold front, they typically choose to use the tailwinds on the back side of a cold front for a more efficient migration. The majority of waterfowl show up after a front.
Warm fronts are the transition zones where masses of warm air are replacing masses of cold air. Warm fronts usually have a more gradual effect than a cold front. Warm fronts typically bring low-hanging clouds, falling pressure, precipitation, and fog followed by stable pressure and rising temperatures. Many hunters expect poor hunting when they see a warm weather forecast, but warm temperatures can be just the ticket if your area has been frozen solid for a week. In many cases, the warmer temperatures will bring back groups of waterfowl. Heavy rains are often associated with winter warm fronts. Those rains can bring immediate and long-term hunting effects. Heavy rains usually keep the birds down, but once the rain stops, the increased water levels and freshly flooded food sources will stir up the birds.
Predicting the weather is a complex task. Plenty of science goes into the prediction, but many unpredictable factors can affect the outcome of the prediction. There are numerous resources that can simplify your understanding of the forecast. The National Weather Service, along with accuweather.com and weather.com, provide highly detailed maps, hourly forecast updates, and Doppler radar imagery. The National Weather Service provides current and predicted river levels as well.
With all of the weather pattern symbols on a surface map, waterfowl hunters should focus on the symbols for warm and cold fronts, low and high pressure, and isobars. Understanding these symbols can help waterfowl hunters predict the severity of an approaching front and what influence it may have on waterfowl. To predict the severity of an impending cold front, look at the isobars. Tightly grouped isobars represent a tight pressure gradient and strong winds. You should also look for the origin of the high pressure following the front. Winter fronts originating in Canada are typically colder and drier. If a winter front originates around the Pacific coast, it will usually be wetter and warmer.
Do not be caught by surprise. Utilize the available weather resources and learn how to read a weather map to predict waterfowl movements. A little effort beforehand can pay huge dividends of full limits of waterfowl.