By David Ismay 

      There are many great resources (local weather forecasts, web-cams, soundings, windtalkers, other pilots with local experience) to help paraglider pilots make consistent and safe decisions about where and when to fly.  But you may not know much about some of the excellent ones, unless you fly noisy, heavy things with engines from your local airport runway!  As an FAA Private Pilot (who prefers flying an aircraft that fits in a backpack), my goal for this article is to explain several of the formal aviation resources used routinely by airplane pilots—like METARs, TAFs, and FDs—that can also give great information (if you know what you’re looking at) to foot-launched pilots. 

Before getting to the specifics, there are a few basics to keep in mind.  First and foremost, the formal aviation weather system was designed and maintained to ensure the safety of flight for commercial and general aviation aircraft.  The Cessna and 747 pilot use the exact same external system—i.e., weather reports, FAA briefers, in-flight updates—in getting you from SFO to New York overnight or getting me from Oakland to Livermore and back.  So that system naturally focuses tightly around airports, established flight routes, and weather in the very short-term—i.e., it reports accurate current-conditions at airports as well as reliable forecasts measured in hours rather than days.  Second, to those of us used to things like online windtalkers with graphical displays and PDA phone web access, the FAA system can feel a little clunky, old-fashioned, and formal which . . . well . . . it is.  The FAA has been broadcasting this information by radio since long before the age of broadband satellite and internet, so it’s coded in a “proprietary” format.  But it’s a good trade-off because these reports are standardized around the world and they’re very reliable.  Finally, as I’ll discuss below, if you’re looking for a forecast more than 24-hours out, all the information you can get reliably—whether you’re talking to an FAA briefer or your local weatherman—is generally coming from a single source: NOAA’s National Weather Service (NWS).

     Current Conditions.  You can get the current weather conditions at hundreds of sites across the country from Aviation Routine Weather Reports, known (for some reason) as METARs.  Most METARs report the conditions right at an airport runway, but there are also a good number of non-airport, state and federal installations that report into the system.  Many reports are automated—entered by the instrument suite itself—though at smaller airports, they are still entered manually.  And unless you’re listening to an automated-site (ASOS/AWOS) reporting by the minute over an FAA VHF frequency, a METAR is an hourly report.  Nevertheless, it’s a great resource if there’s one near a paragliding site and, in California alone, there are some 150 METAR sites—94 of which are automated and available by local phone access. 

      So, what’s in a METAR report, and how do you read it?  Here’s an example of a (slightly tweaked) report on January 27, 2007, from Ukiah Municipal Airport, the closest reporting station to Potato and Elk Mountain: 

KUKI 271956Z AUTO 08010KT 10SM SCT070 11/04 A3003 RMK AO2 SLP169 T01110039

“KUKI” – Station Identifier: each station has a 3 or 4-digit identifier (for airports it’s the airport code on the charts, e.g., KSFO and KOAK for San Francisco International and Oakland International).  Most online resources use this to retrieve the report, and if you’re talking to a briefer on the phone, you can just give the airport name. 

“271956Z” – Time of Report: the day of the month followed by the time in “Zulu” (the same as Universal Coordinated Time (UTC) or Greenwich Mean Time (GMT)).  Subtract 8 hours for Pacific Standard (PST) or 7 hours for Pacific Daylight Savings (PDT) times.  This was for 1956Z (or 11:56 am in Ukiah) on the 27th. 

“AUTO” – Modifier: notes an automated report (there will be nothing here if it’s a manual entry). 

“08010KT” – Wind: direction in degrees True1 followed by speed in knots; here, winds from the east, 080° T, at 10 knots (11.5 mph).  If, for example, there were gusts to 20 knots, it would read “08010G20KT”. You might also see “00000KT” which means winds are calm, or something like “VRB04KT”, meaning the wind direction is variable at 4 knots. 

“10SM” – Visibility: reports the greatest distance (in statute miles) a ground observer can see and identify objects through at least half the horizon, here, 10 miles. 

“SCT070” – Weather: lots of conditions are reported here (e.g., thunderstorms “TS”, rain “RA”, showers “SH”), but on days with a chance of paragliding, you’ll normally just see the sky condition, i.e., the reported cloud layer(s), here, “scattered” (covering 3/8 to 4/8 of the sky) at 7,000 feet.  Multiple cloud layers are reported one after the other, and “SKC” or “CLR” both report clear skies. 

“11/04” – Temperature/Dewpoint: reported in degrees Celsius, here, temperature is 11° C (52° F), and dewpoint is 4° C (40° F). 

“A3003” – Altimeter Setting: reports the barometric pressure in inches of mercury, here, 30.03 in. Hg.. 

“RMK” – Remarks: reports various details like, here, the type of automated instrumentation: “AO2”, sea-level pressure in millibars: “SLP169” (1016.9 mb), and a more accurate temperature/dewpoint in tenths °C: “T01110039” (11.1° C/3.9° C). 

The basics of a METAR are easy to get used to, but for an explanation of all the various codes you might encounter, look on the NWS website at http://www.srh.noaa.gov/bna/educate/metar/metar-pg13-rmk.html. 

      Forecast Conditions.  Most of the same codes (thankfully) are used in Terminal Aerodrome Forecasts, or TAFs.  These are 24-hour general forecasts for larger airports only—there are about 50 in California—issued four times a day at 0000Z, 0600Z, 1200Z, 1800Z (or 4pm, 10pm, 4am, 10am PST).  Here’s one from Oakland, again from January 27, 2007: 

KOAK 271720Z 271818 VRB03KT 2SM -RA BKN003

     FM1900 21006KT 6SM HZ VCSH BKN010

     FM2200 30005KT P6SM BKN050

     FM0300 VRB03KT P6SM SCT050 BKN090 

“271818” – Valid Period: after the same station ID and report date/time codes, it shows the range of time for which the forecast was valid, here, from 1800Z (10:00am PST) on the 27th until the same time on the 28th.

Gregg Hackett flies at Goat Rock - photo by Ann Sasaki