A METAR tells you what the weather is right now. A TAF tells you what it is expected to be over the next 24 to 30 hours. For drone pilots planning a shoot or a mapping mission, a TAF is the most useful weather document to read the night before -- before you load equipment, drive to the site, and set up.
TAFs are issued every 6 hours (at 0000, 0600, 1200, and 1800 UTC) for airports with instrument approaches. They are not available for every location, but any airport with a METAR will typically have a TAF.
TAF Structure
A TAF follows the same general structure as a METAR but covers a time range rather than a single observation. Here is an example:
TAF KHWD 111730Z 1118/1218 27010KT P6SM SKC
FM1200 26015G25KT 5SM HZ BKN025
TEMPO 1200/1204 VRB20KT 2SM TSRA OVC010Breaking this down:
TAF KHWD -- TAF for Hayward Executive Airport (ICAO code KHWD)
111730Z -- issued on the 11th at 1730 UTC
1118/1218 -- valid from the 11th at 1800 UTC to the 12th at 1800 UTC (24-hour window)
27010KT P6SM SKC -- the base forecast: wind 270 degrees at 10 knots, visibility greater than 6 statute miles, sky clear
FM1200 -- "From 1200 UTC" -- a permanent change in conditions beginning at this time: 26015G25KT means wind 260 degrees at 15 knots gusting to 25 knots; 5SM HZ means 5 statute mile visibility in haze; BKN025 means broken clouds at 2,500 ft AGL
TEMPO 1200/1204 -- temporary conditions between 1200 and 1204 UTC: VRB20KT (variable wind 20 knots), 2SM TSRA (2 miles visibility in thunderstorm and rain), OVC010 (overcast at 1,000 ft AGL)
Change Group Indicators
TAFs use specific codes to indicate how and when conditions change.
FM (From) -- a permanent change. Conditions before FM no longer apply after the time shown. Use FM groups to understand the overall trajectory of the day's weather.
TEMPO -- temporary fluctuations expected to last less than one hour and occur less than half the time in the period shown. TEMPO conditions may affect your flight window but are not the dominant pattern.
PROB -- probability. PROB30 means a 30 percent chance of the conditions following. PROB40 means 40 percent. These appear when forecasters are not confident enough to include a condition in the main forecast but consider it worth noting.
BECMG (Becoming) -- a gradual change expected to occur within the time window shown and then persist. Less abrupt than FM.
What to Look for as a Drone Pilot
Wind and gusts. The wind group in each change period shows what you can expect at the airport -- not necessarily at your flight site, but it is a strong indicator. Plan around the gusts figure, not the average wind speed. If FM1400 shows 15G28KT, expect 28-knot gusts after 1400 UTC.
Visibility. Any visibility below 3 SM prohibits Part 107 operations. Look for HZ (haze), FG (fog), BR (mist), RA (rain), and SN (snow) -- each can drive visibility below legal minimums.
Ceiling. Sky condition codes tell you the height of cloud layers. BKN and OVC (broken and overcast) indicate significant cloud coverage. A ceiling below your planned operating altitude may not prohibit flight -- you can fly below a cloud layer -- but ceilings below a few hundred feet create practical problems for VLOS operations.
Thunderstorms. TS anywhere in the TAF for your operating window is a serious flag. TSRA (thunderstorm with rain) and VCTS (vicinity thunderstorms) both warrant rescheduling.
UTC to Local Time Conversion
TAFs use Zulu time (UTC). Convert to your local time before planning.
California is UTC-7 during Pacific Daylight Time (PDT, March through November) and UTC-8 during Pacific Standard Time (PST, November through March).
If a TAF shows FM2000Z during PDT, that is 1:00 PM local time. Get comfortable converting -- misreading Zulu time is one of the most common errors when planning flights around TAF windows.
TAF Coverage Area
A TAF applies to conditions within 5 statute miles of the airport it is issued for. If your flight site is 8 miles from the nearest TAF station, treat the forecast as directional guidance rather than a precise prediction for your location.
Open terrain, coastal proximity, and elevation differences all create microclimatic variations that TAFs cannot capture. The METAR at the airport gives you the current observed conditions. The TAF gives you the forecast trend. Use both.
TAF in UAS SkyCheck
UAS SkyCheck's Pilot-tier weather panel includes the TAF outlook from the nearest TAF-issuing airport. The TAF section shows the plain-English interpretation of the 6-hour outlook, flags deteriorating conditions, and identifies the source airport and its distance from your location.
This is particularly useful for planning sessions the evening before a shoot -- you can run a check at home, read the TAF outlook, and make a go/no-go decision before committing to an early morning drive to the site.
Putting It Together
A practical TAF workflow for a morning shoot:
- The evening before: run a check in UAS SkyCheck for your planned location
- Read the full TAF for the nearest station -- identify any FM, TEMPO, or PROB groups during your planned window
- Note the wind, visibility, and ceiling for your launch time and planned duration
- The morning of: run a second check and compare the METAR to the TAF prediction
- If actual conditions match or are better than forecast, proceed. If conditions are worse, re-evaluate.
A TAF that looked acceptable the night before may show afternoon TEMPO thunderstorms. Getting up early and flying before that window is not just efficient -- it is the safer operation.
UAS SkyCheck Pilot tier includes the TAF outlook for the nearest airport alongside live METAR and wind data. Check your full weather picture before every flight at uas-skycheck.app.