Below are some weather maps from the National Weather Service that show weather that can affect either you day's birding or bird movements (especially during migration). Below the maps are legends showing what all the symbols mean.

Today's Forecast

12 Hour Fronts/Precipitation (forecast)

Current Surface Analysis (click for full-size version)

Surface Analysis Loop

Click here. This will open a new window with an animated loop.

Quantitative Precipitation Forecast (amount of rain/snow)

Satellite Surface Map Loop

Current Temperature Contour Plot

Current Weather

Current Radar (from Fox Chicago )

Current Satellite

Fronts Legend

A hash mark denotes a change in frontal type, as in the example below.

<span face=Arial,Helvetica> For more information about an item marked with a (*), click on the appropriate link:

WEATHER

A weather symbol is plotted if at the time of observation, there is either precipitation occurring or a condition causing reduced visibility.
Below is a list of the most common weather symbols:

WIND

Wind is plotted in increments of 5 knots (kts), with the outer end of the symbol pointing toward the direction from which the wind is blowing. The wind speed is determined by adding up the total of flags, lines, and half-lines, each of which have the following individual values:

Flag: 50 kts
Line: 10 kts
Half-Line: 5 kts

If there is only a circle depicted over the station with no wind symbol present, the wind is calm. Below are some sample wind symbols:

PRESSURE

Sea-level pressure is plotted in tenths of millibars (mb), with the leading 10 or 9 omitted. For reference, 1013 mb is equivalent to 29.92 inches of mercury. Below are some sample conversions between plotted and complete sea-level pressure values:

410: 1041.0 mb
103: 1010.3 mb
987: 998.7 mb
872: 987.2 mb

PRESSURE TREND

The pressure trend has two components, a number and symbol, to indicate how the sea-level pressure has changed during the past three hours. The number provides the 3-hour change in tenths of millibars, while the symbol provides a graphic illustration of how this change occurred. Below are the meanings of the pressure trend symbols:

SKY COVER

The amount that the circle at the center of the station plot is filled in reflects the approximate amount that the sky is covered with clouds. Below are the common cloud cover depictions: