All about Surface Station Plots!

Image Description: Map of U.S Surface Station Models Map of the continental U.S with Surface Station Models scattered throughout.

What is a Surface Station Model?

They are used to show many weather observations on a map.
Show observations are at the surface.
Can show the spatial relationship of weather observations.

Temperature & Dewpoint Temperature

Temperature (shown in red here) and Dewpoint Temperature (shown in green here) are reported in °F to the nearest whole number.

In this example:

Temperature = 56°F

Dewpoint temp = 50°F

Wind

Wind barbs (plotted in magenta here) represent the wind direction (in degrees) and the wind speed (in knots).

In this example, the wind is coming from the north (0 degrees) at 15 knots.

If there is a wind gust reported, it will be written on top.

In this example, the wind is from the north at 15 knots gusting to 27 knots.

If the winds are calm, they are indicated by a circle around the central point.

In this example, the wind would be reported as calm.

Cloud Cover

The center circle represents cloud cover.

Image Description: Cloud Cover Indicators

The following indicators refer to the center circle of a surface station model.

Open, not filled : Clear Conditions
Open, not filled: Sky clear
A line down the middle : Few Clouds (12.5% - 25%)
1/4 filled : Scattered Clouds (37.5 - 50%)
3/4 filled : Broken Clouds (62.5% - 87.5%)
Filled in : Overcast (100%)
"X" : Sky is Obscured
"M" : Sky Cover is Missing

In this example, the cloud cover is overcast.

Visibility

Visibility is reported in statute miles (shown in light blue here).

In this example, the visibility is 3/4 statute miles.

Significant Weather

Significant Weather is reported by special symbols (shown in yellow here).

Image Description: Common Weather Symbols Left Column 2 dots - Light Rain 3 dots - Moderate Rain 4 dots - Heavy Rain 2 stars - Light Snow 3 stars - Moderate Snow 4 stars - Heavy Snow 2 apostrophes - Light Drizzle Triangle with dot inside - Ice Pellets (Sleet) Sideways "S" with a dot inside - Freezing Rain Sideways "S" with an apostrophe inside - Freezing Drizzle Right Column Upside down triangle with a dot on top: Rain Shower Upside down triangle with a star on top: Snow Shower Two triangles put together at the base : Showers of Hail Two, perpendicular arrows : Drift/Blowing Snow "S" with an arrow crossing it : Dust Storm 3 horizontal lines : Fog Infinity Sign : Haze Vertical line with a squiggle : Smoke "R" with an arrow : Thunderstorm Cyclone symbol : Hurricane

Image Description: Significant Weather Example The symbol used in this example is two dots. This represents light rain.

In this example, the significant weather is light rain.

Sea Level Pressure

Sea-level pressure (SLP) is reported in the top right (shown in pink here), and is done in the same manner as a METAR:

A decimal goes between the second and third numbers.
If the first two numbers are:
- - > 50, add a 9 on the front
  - < 50, add a 10 on the front

Image Description: Sea Level Pressure SLP is reported as a 3 digit number in the top right of a surface station model. Review previous instructions for how to decode. Number in top right is 107

In this example, the sea level pressure is 1010.7 mb.

Pressure Tendency

Pressure Tendency is reported in the bottom right (shown in purple here).

It is defined as the 3-hour pressure change, in tenths of a mb.
The symbol illustrates how this pressure change occurred over the past 3-hours.

$Image Description: Pressure Tendency Symbols Left column Backwards slash (\) : Continuously Falling \ with a short, flat line on the bottom (\_) : Falling then Steady \ with a short, angled line on the bottom : Falling before a lesser rise \ with a short, angled line at the top: Riing before a greater fall Right Column: Forward slash (/) : Continuously rising / with a short, flat line at the top : Rising, then steady / with a short, angled line at the bottom : Falling before a greater rise / with a short, angled line at the top : Rising before a lesser fall Flat line (-) : Steady$

$Image Description: Pressure Tendency Example Pressure tendency is highlighted in purple at the bottom right of the surface station plot as: -15\$

In this example, pressure continuously fell 1.5 mb in the past 3 hours.

Can you decode this surface station model? (Answer revealed if you click the arrow!)

Temperature: 20 °F

Dew Point: 16 °F

Wind: 5 kts from the north

Cloud Cover: Sky Cover Missing

Visibility: 8 Statute Miles

Current Weather: Thick Fog

Sea-level Pressure: 980.7 mb

Pressure Tendency: Increasing 2.8 mb continuously

$Image Description: Example of a Surface Station Model Wind: 5 kts from the North Barb is pointing in the North Direction. One, half line representing 5 kts. Cloud Cover: Sky Cover Missing The circle has an "M" on the inside Temperature: 20 °F Noted in the top left Dew Point: 16 °F Noted in the bottom left Visibility: 8 Statute Miles Noted to the left the significant/current weather symbol Current Weather: Thick Fog Symbol is three thick lines in between the temperature and dew-point temperatures Sea-level Pressure: 980.7 mb Noted as 807 in the top right Refer to "Sea-level" pressure section to learn how to decode the number Pressure Tendency: Increasing 2.8 mb continuously Noted as +28\ in the bottom right Refer to the "Pressure Tendency" section to learn how to decode the number$

AtSci 110 Surface Station Model Appendix

Previous Page: TAFs | Next Page: Upper-Level Station Models

Page updated

Google Sites

Report abuse