Pilotised

Weather

Weather Radar & SIGMETs

Two hours of precipitation radar you can scrub through, every active SIGMET drawn as a hazard area you can filter by level, and the flight category each field is reporting right now. Tap an area for its levels, validity and movement, or a field for the wind, the runway it favours and how old the report is.

Loading the map

Radar frames, hazard areas and airfield reports arrive one after the other.

What the colours mean

Colour on the map always means weather. Airfield dots are sized by aerodrome class and never coloured by it, so nothing competes with the picture. The key on the map lists only the layers you have switched on, including the radar scale in dBZ.

Flight category, observed

  • VFR · Ceiling above 3,000 ft and visibility over 5 miles
  • MVFR · Ceiling 1,000 to 3,000 ft or visibility 3 to 5 miles
  • IFR · Ceiling 500 to 1,000 ft or visibility 1 to 3 miles
  • LIFR · Ceiling below 500 ft or visibility under 1 mile

Hazard areas

  • Thunderstorms and tropical cyclone
  • Volcanic ash
  • Turbulence and mountain wave
  • Icing
  • IFR conditions, mountains obscured and anything else

Drawn as hatched outlines rather than solid fills, so the radar underneath stays readable. The hatch angle and the dash of the outline differ by hazard family, so two families sharing a colour still separate.

Thunderstorm reports

  • Thunderstorm at the field, solid ring and bolt
  • Thunderstorm in the vicinity, dashed ring
  • Cumulonimbus reported, ring marked CB

Each one sits beside its airfield on a short leader, not on top of it, so the field stays visible and can still be opened.

Reading the map

The level filter asks the question a pilot asks first: does this affect me at my altitude. A SIGMET is a volume, and areas that publish no level are always kept on the map and labelled as such, because an unknown level is not the same as a level that does not apply.

Hazard areas and airfield reports are always current. Scrub the loop to a nowcast frame and they dim, because they were never part of that picture. The timeline says so on every frame.

Radar is full resolution to zoom 7 and upscaled beyond it, which the layer panel states where you can see it. Lower the radar opacity to read the coastline underneath.

The address bar carries the centre, zoom, layers, level band and open airfield, so a view can be sent to whoever you are flying with.

Where the data comes from

SIGMETs come from NOAA’s Aviation Weather Center, from both the international and the US domestic feed, so UK FIRs such as London and Scottish appear alongside the rest of the world. Movement is read from the numeric fields where the feed publishes them and from the report text where it does not, which is how the UK gets a vector at all.

G-AIRMETs are a United States product, so they are an optional layer rather than an always-on one: switch them on and you get turbulence, icing, IFR conditions, mountain obscuration, low-level wind shear and freezing-level contours, each with the flight levels it applies between. There is no equivalent outside the US, so for low-level hazards elsewhere use your national forecast, which in the UK is the Met Office F215.

Flight category and thunderstorm reports are what aerodromes are publishing in their own METARs, not a model and not a lightning-strike network. Radar comes from RainViewer, which composites national radar networks; the timeline shows the exact age of the frame you are looking at rather than asking you to assume one.

For training and reference only. Always use an approved briefing source for operational decisions.