It is possible to generate an image that depicts a TAF forecast in N-Flight Planning (N-FP). Currently, this is available through the Context menus from the map. This article describes how to interpret what the graphical display is showing and the options available to control its appearance. The sample image below displays most of the content of a TAF.
TAF from sample image
TAF CYVR 171140Z 1712/1818 31008KT P6SM FEW040 BKN240
FM171800 28010KT P6SM FEW060 SCT080
TEMPO 1718/1805 P6SM -SHRA SCT040 BKN060
BECMG 1800/1802 12006KT
FM180500 10012KT P6SM SCT012 BKN060
TEMPO 1805/1808 5SM -SHRA BR BKN012 OVC060
FM180800 12010KT P6SM SCT008 OVC030
TEMPO 1808/1818 4SM -SHRA BR OVC008
RMK NXT FCST BY 171500Z
General
The image is broken down in one-hour increments along the x-axis.
A label for the hour is drawn at six-hour intervals. This example image shows 24, but the feature has been updated to show '00'.
A horizontal line will be drawn at each 10,000-foot (FL100) increment.
A solid line will be drawn at ground level. Some space is provided underneath to show that the significant weather can be seen when the ceiling is very low.
A green line is drawn to show either:
The current time if no flight is selected
The ETD if a flight is selected.
Visibility
Line of circles at top of image
Shade of circle changes on logarithmic scale:
9999m = 100% (white)
1000m = 50% (gray)
100m = 0% (black).
Wind
Second line of circles from top
Notch shows direction of wind
The gust value will be used if present.
The circle will begin to be shaded light red when the warning threshold is reached (10kt).
The circle will be a solid red when the danger threshold is reached or exceeded (40kt).
Cloud
Clouds and ceiling are displayed for FL000 to FL200 (default).
Cloud shade is determined by amount (OVC, BKN, SCT, FEW) where OVC will be darkest, and FEW will be lightest.
The ceiling (usually from OVC or BKN clouds) will be displayed as a red line.
Significant Weather
Significant weather will be displayed as a colored region below the ceiling (or lowest cloud group).
Color is determined by the weather type:
The following types will be given a blue shade:
Showers (SH)
Thunderstorms (TS)
Drizzle (DZ)
Rain (RA)
Squall (SQ)
Funnel cloud (FC).
The following types will be given a gray shade:
Snow (SN)
Snow grains (SG)
Ice crystals (IC)
Ice pellets (IP)
Hail (GR)
Mist (BR)
Fog (FG).
The following types will be given a red shade:
Smoke (FU)
Volcanic ash (VA)
Dust (DU)
Sand (SA)
Haze (HZ)
Dust whirls (PO)
Sandstorm (SS)
Dust storm (DS).
Each additional weather type will increase the intensity of the color (e.g.: TSRA will be darker than just RA).
The intensity of the color will increase for heavy intensity (+).
The intensity of the color will decrease for light intensity (-).
How Conditions are Applied
There are three types of change types in a TAF:
The initial type or FM (from) type establishes a new set of conditions completely replacing any previously stated conditions.
Change types, such as BECMG (becoming), will replace only specific elements of the previous time group. Therefore, a BECMG with only a visibility value, would only change the visibility going forward and other elements would remain the same. The exception would be SigWx, which will always use the current periods values (even when empty).
There are provisional types, such as TEMPO (temporary) or PROB (probability), that may happen for an intermediate period, but otherwise, the original values are retained. By default (see configuration), PROB and TEMPO values will override values, if they are more limiting. Therefore, if there was a temporary ceiling lower than the previously mentioned value, it would be used.