Weather Fronts and Pressure Centers

Weather fronts appear as lines that indicate the leading edge of an air mass.

 

Front Symbol

Description

 

 

 

 

 

 

 

Cold front

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Warm front

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stationary front

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Occluded front

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Trough

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pressure-center symbols often appear near weather fronts.

Pressure- Description

Center

Symbol

Indicates a low-pressure center, which is a region of relatively lower pressure. Moving away from a low- pressure center results in increased pressure. Winds flow counterclockwise around low-pressure centers in the northern hemisphere.

Indicates a high-pressure center, which is a region of relatively higher pressure. Moving away from a high- pressure center results in decreased pressure. Winds flow clockwise around high-pressure centers in the northern hemisphere.

Viewing a Marine Forecast or an Offshore Forecast

1Select Weather > Menu > Weather Menu > Change Weather > Forecast.

2Pan the chart to an offshore location.

The Marine Forecast or Offshore Forecast options appear when forecast information is available.

3Select Marine Forecast or Offshore Forecast.

City Forecasts

City forecasts appear as weather symbols. The forecast is viewed in 12-hour increments.

Symbol

Weather

Symbol

Weather

 

Partly cloudy

 

 

 

 

 

 

 

Fair (sunny, hot, clear)

 

 

 

 

 

 

 

 

 

 

 

Cloudy

 

 

 

 

 

 

 

Rain (drizzle, sleet, showers)

 

 

 

 

 

 

 

 

 

 

 

Windy

 

 

 

 

 

 

 

Foggy

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thunderstorms

 

 

 

 

 

 

 

Snow (snow showers, flurries,

 

 

 

 

 

 

 

 

 

blizzard, blowing snow, sleet,

 

 

 

 

 

 

 

 

 

freezing rain, freezing drizzle)

 

Smoke (dusty, hazy)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Viewing Sea Conditions

The Sea Conditions chart shows information about surface conditions, including winds, wave height, wave period, and wave direction.

Select Weather > Menu > Weather Menu > Change Weather > Sea Conditions.

Surface Winds

Surface wind vectors appear on the Sea Conditions chart using wind barbs that indicate the direction from which the wind is blowing. A wind barb is a circle with a tail. The line or flag attached to the tail of the wind barb indicates the wind speed. A short line represents 5 knots, a long line represents 10 knots, and triangle represents 50 knots.

Wind Barb

Wind Speed

Wind Barb

Wind Speed

 

 

 

 

Calm

 

 

 

 

 

 

 

20 knots

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5 knots

 

 

 

 

 

 

 

50 knots

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10 knots

 

 

 

 

 

 

 

65 knots

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15 knots

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Wave Height, Wave Period, and Wave Direction

Wave heights for an area appear as variations in color. Different colors indicate different wave heights, as shown in the legend.

The wave period indicates the time (in seconds) between successive waves. Wave period lines indicate areas that have the same wave period.

Wave directions appear on the chart using red arrows. The direction of each arrow pointer indicates the direction in which a wave is moving.

Viewing Forecast Sea Conditions Information for Another Time Period

1Select Weather > Menu > Weather Menu > Change Weather > Sea Conditions.

2Select an option:

•To view forecasted sea conditions for the next 12 hours,

select Next Forecast or , and to view forecasts, up to 36 hours, in 12-hour increments, select Next Forecast or again.

•To view the forecasted sea conditions for the previous 12

hours, select Previous Forecast or , and to view previous forecasts, up to 36 hours ago, in 12-hour increments, select Previous Forecast or again.

Viewing Fishing Information

The weather Fishing chart shows present water temperature, present surface pressure conditions, and fishing forecasts.

Select Weather > Menu > Weather Menu > Change Weather > Fishing.

Surface Pressure and Water Temperature Data

Surface-pressure information appears as pressure isobars and pressure centers. Isobars connect points of equal pressure. Pressure readings can help to determine weather and wind conditions. High-pressure areas are generally associated with fair weather. Low-pressure areas are generally associated with clouds and the chance of precipitation. Isobars packed closely together show a strong pressure gradient. Strong pressure gradients are associated with areas of stronger winds.

Pressure units are shown in millibars (mb), inches of Mercury (inHg), or hectopascals (hPa).

Colored shading indicates the surface temperature of the water, as shown in the legend in the corner of the display.

Forecasting Fish Locations

You can show areas that contain optimal weather conditions for specific species of fish.

NOTE: This feature is not available on all devices and in all subscriptions.

1From the weather Fishing chart, select Menu > Weather Menu > Fish Species.

2Select a species of fish.

3 Select On.

4Repeat steps 2 and 3 to show areas with optimal weather conditions for additional species of fish.

Shaded areas indicate optimal fishing areas. If you have selected more than one species of fish, you can select a shaded area to view the fish species that are included in the shaded area.

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