Forecast radar where you'll be, when you'll be there.
Radar Forecast answers one question: what will the weather be along my planned route at the hour I get there?
Enter a route, a ground speed and a departure time. The app draws the route, computes distance and time en route, and puts an aircraft on the map in the right place at the right time. Drag the timeline and the aircraft moves while the radar changes underneath it, so the picture you are looking at is the forecast for your position at that hour.
Radar Forecast takes the most recent forecast data available for every hour and stitches it into one timeline. HRRR supplies the first 48 hours and RRFS the rest, out to 84. Put your route over it and you can see what the weather will be doing, and where the aircraft will be when it does.
HRRR and RRFS are NOAA's two high-resolution forecast models. Both update every hour on a 3 km grid. Every run looks 18 hours ahead, and the runs at 00, 06, 12 and 18 Z look further: 48 hours for HRRR and 84 for RRFS.
The forecasts are free to download, but they are published run by run, and a run does not arrive all at once. An HRRR run starts posting about 50 minutes after its cycle time. The 21 Z run, for example, begins around 21:50. It can take up to another hour to finish, and RRFS's 84-hour runs take longer still. On their own maps, it is also hard to see where you plan to fly.
High-Resolution Rapid Refresh, NOAA
A 3 km convection-allowing model over the continental United States. Every hourly run reaches 18 hours ahead; the 00, 06, 12 and 18 Z runs reach 48. The app always shows the newest frames available, so the far end of the timeline shortens as a run ages and springs back when the next 48-hour run posts.
Rapid Refresh Forecast System, NOAA
NOAA's next convection-allowing model: hourly updates on a 3 km grid covering North America, built on the FV3 dynamical core. Where HRRR's synoptic runs stop at 48 hours, RRFS reaches 84 from the same 00, 06, 12 and 18 Z cycles. Operational from 14 October 2026.
Three inputs, one slider.
Type identifiers separated by spaces — KFWS KLIT KMEM — then a ground
speed in knots and a departure time in Zulu. Plot draws the route and shows
distance and time en route.
Each step of the timeline is one forecast hour. Left of now, step back through observed radar to see which way a cell is actually tracking. Right of now, the aircraft slides along the route, so the radar you see is the forecast for your position, not for a fixed spot on the map.
Read a cell by its worst return.
Color is reflectivity in dBZ, and the same scale is used for forecast and observed frames, so shading is comparable along the whole timeline. Blues are light returns, below 20 dBZ. Radar Forecast uses the same color scheme as the Garmin Pilot app, which places the dark green at the 30 dBZ level.
Dark green is 30 dBZ — the point at or above which to use extreme caution. If a cell contains anything above dark green, treat the entire cell as that highest intensity.
Route around it, and stop if you need to.
Long-press the map to find nearby fixes and tap one to add it to the route. Tap the route to open the planner, where you can reorder fixes by dragging, delete them, and turn up to three intermediate airports into stops.
Give a stop its ground time in minutes and the aircraft pauses there, so every later leg lines up with the right forecast hour. A fuel stop or a weather hold moves the whole downstream picture, which is the point.
If you know the field but not the identifier, tap the magnifier in the route dialog. Type two or more letters and it searches airports by name — larger fields first, then alphabetically. Pick one and the map flies to it, the airport pulses so you can see which it chose, and the identifier is appended to your route, ready to plot.
Somewhere to route to.
Tap Nav to display fixes. Zoom in to display more fixes and zoom out to display fewer. Long press a location to display a list of nearby fixes. Tap one in the list to add it to your route. Use this feature to route around expected weather.
Display street map, VFR or IFR charts.
The base map button cycles between a street map and the FAA's VFR sectional and IFR enroute charts.
Headwind or tailwind, by leg.
Use the wind table to better estimate your ground speed. It gives the average head or tail wind component for each leg at each cruising altitude. Samples are taken every 50 nautical miles, each one at the time the aircraft actually crosses that point, then averaged across the leg.
The altitudes follow the hemispheric rule — odd thousands eastbound, even westbound — picked from each leg's true course. Tap East or West to force the other direction, and tap again to go back to automatic. Tap IFR to switch to VFR cruising altitudes, 500 feet higher. Tap High to display flight level altitudes, FL200 to FL450.
Probability and severity, by altitude.
Tap Ice to display NOAA's in-flight icing analysis, filtered to the altitude band you care about. Drag the altitude control and the layer redraws.
Tap Severity to choose what the layer shows: severity; severity only where the probability is 25% or more; severity only where it is 50% or more; or probability alone.
Tap anywhere on the map to open the icing column for that point: every level from 2,000 to 30,000 feet, highest first, the way you would read it on a climb. Each level shows its severity — trace, light, moderate or heavy — as a colored bar beside its probability, with an S where supercooled large drops are forecast. The heading gives the base and top of each icing layer, so two layers with clear air between them read as two layers, not one.
The systems behind the cells.
Radar shows you the weather; the prog chart shows you what is driving it. Tap Prog to draw the Weather Prediction Center's surface analysis — cold, warm, stationary and occluded fronts, with highs and lows — over NDFD's forecast weather type, so you can see rain, snow, thunderstorms and freezing precipitation as shaded areas.
It moves with the slider like everything else. Step forward and the fronts march across the map with the cells, which is what tells you whether a line of storms is going to clear your destination before you get there or sit on it. Fronts are published out to 48 hours; past that the shading continues alone.
Another forecast source.
Tap Wx to display METARs and TAFs. Stations are drawn as colored dots in the familiar flight categories, and they come from the forecasters and the stations themselves, not from a model. Where a TAF disagrees with the forecast radar, that disagreement is worth your attention.
METARs and TAFs follow the slider. At the "now" end of the timeline a station shows its METAR, which stays valid for an hour after it was issued. Move the slider forward and each station switches to the TAF period covering that time, so the colors you see are the categories forecast for the hour you would actually arrive. Where a METAR and a TAF are both valid, the METAR wins — an observation beats a forecast. Push far enough ahead that a station's TAF has run out and its dot simply disappears rather than showing you something stale.
Tap any station for its decoded METAR and TAF in full.
Radar imagery carries a level of detail that is misleading. Storms are not in the exact location shown, nor at the exact intensity shown; weather moves and changes constantly. What a forecast does give you is a reasonable estimate of where the weather will be, so you can plan around it.
Radar Forecast is a planning aid. It is not a certified EFB, not authoritative, and not for primary navigation. Always get an official preflight briefing — use ForeFlight, 1800wxbrief.com or aviationweather.gov for go/no-go decisions.
Observed radar is older than it looks, too. In June 2012 the NTSB warned that the NEXRAD mosaic on a cockpit display can be 15 to 20 minutes older than its age indicator shows, and that the display "depicts where the weather WAS, not where it IS." The FAA's current guidance tells pilots to assume data link weather is always at least 7 to 8 minutes older than its time stamp, and to use it only for broad strategic avoidance of adverse weather.
NTSB Safety Alert SA-017, In-Cockpit NEXRAD Mosaic Imagery (June 2012, revised December 2015). FAA AC 00-63B, Use of Flight Deck Displays of Digital Weather and Aeronautical Information (3 June 2024), ¶8.2.1.