998: Pressure, to the nearest tenth of a millibar. Add either a 10 or 9 in front based on which would bring the value closer to 1000. The pressure here is 999.8 millibars (mb).
-03: Pressure tendency the last 3 hours, to the nearest tenth of a millibar. The pressure here has fallen .3 mb the last 3 hours
Middle Circle (filled in w/ mostly black): Cloud cover. It's mostly black showing that this station is mostly cloudy. Technically, this represents a broken sky with 7/8 of the sky covered with clouds.
Black line, extending from circle: Wind barb. It points to where the wind is coming from. The wind here is from the southwest, hence a southwest wind. The two lines extending represent 20 knot winds with each line representing 10 knots.
Symbol between 77 and 68: This is the present weather field and in this case shows that there is a thunderstorm occuring at the station
symbol next to -03: That line is the pressure tendency. The 1st hour the pressure was steady, then fell the last two hours.
Triangle(with a dot above it): Previous weather, or the weather one hour ago. In this case it was a light rain shower.