The Winds Aloft Forecast, the FB Winds Product That Rewrites Your Groundspeed Before You Leave the Ramp, and the Altitude-Shopping Decision Every Cross-Country Pilot Needs Before Filing

The Winds Aloft Forecast - formally called Forecast Winds and Temperatures Aloft, and commonly referred to by instructors as the FB winds - is one of the most consequential products in your cross-country planning toolkit. It tells you the expected wind direction, wind speed, and temperature at a series of standard altitudes across the country. If you file for three thousand five hundred feet without consulting it, your groundspeed, fuel burn, and arrival time are all estimates built on assumptions you haven’t verified.

What Is the Winds Aloft Forecast and Where Do You Find It?

The official product lives at the Aviation Weather Center through aviationweather.gov. It’s free, it updates regularly, and it covers the entire country. The name “FB winds” comes from the product’s legacy short code designation - you’ll hear both terms used interchangeably by instructors.

The forecast covers standard altitudes: 3,000 feet, 6,000, 9,000, 12,000, 18,000, 24,000, 30,000, and higher. For most student pilots flying a Cessna 172 or Piper Cherokee on early cross-countries, the 3,000, 6,000, and 9,000-foot levels are the altitudes that drive your planning.

How Do You Read the Winds Aloft Forecast Data?

Each altitude level displays a compact string of numbers. A reading like 21005+09 breaks down as follows:

• First three digits - wind direction in degrees magnetic. 210 means the wind is from 210 degrees.
• Next two digits - wind speed in knots. 05 means five knots.
• Number after the sign - temperature in degrees Celsius. +09 means positive nine degrees Celsius.

The full string tells you: at that altitude, expect a five-knot wind from 210 degrees with a temperature of +9°C. Record that on your navigation log and work through what it means for each planned leg.

What Are the Special Wind Codes to Know?

9999 means winds are light and variable - less than five knots. No meaningful wind component in any direction. For a cross-country, that’s a clean fuel picture: your planned groundspeed is your actual groundspeed.

The second code applies to very high winds. If the first two digits are 50 or greater, subtract 50 from the direction and add 100 knots to the speed. A reading of 7738 decodes to a wind from 270 degrees at 138 knots. You won’t encounter that on a local cross-country, but the code exists and you need to recognize it when flying higher or studying jet stream behavior.

Why Don’t Surface Winds Tell the Whole Story?

The lowest altitude in the Winds Aloft product is 3,000 feet - that’s the floor. It does not reflect surface conditions, and surface winds and winds aloft can describe completely different atmospheres.

A calm surface wind observation does not mean calm air at 4,500 feet. Wind can accelerate significantly with altitude, and that transition happens quickly in certain conditions. The classic trap: calm at the surface, strong southwest flow at 6,000 feet. You climb through 2,000 feet and suddenly you’re fighting a headwind that wasn’t visible in any surface observation - but was clearly shown in the winds aloft forecast.

Always cross-reference the winds aloft forecast with surface winds from the nearest METAR or Terminal Aerodrome Forecast (TAF). A sharp jump in wind speed between the surface and 3,000 feet tells you something real about how the atmosphere is layered and what kind of ride to expect in the lower altitudes.

How Do You Shop for the Best Cruise Altitude?

Altitude shopping means you don’t pick a cruise altitude out of habit. You compare the wind component at every legal altitude for your planned legs and choose the one that gives you the best groundspeed for your route. The Airmen Certification Standards (ACS) expects you to demonstrate this during your practical test.

The rule first. Under FAR 91.159, when flying more than 3,000 feet above the surface:

• Magnetic courses 000–179°: fly odd thousands plus 500 feet - 3,500, 5,500, 7,500, 9,500
• Magnetic courses 180–359°: fly even thousands plus 500 feet - 4,500, 6,500, 8,500

That rule sets your menu. Altitude shopping is choosing intelligently from within it.

Here’s a worked example. Flying from Wichita to Tulsa, the direct magnetic course is approximately 120 degrees - odd-thousands-plus-500 territory. Legal options: 3,500, 5,500, and 7,500 feet.

Pull the winds aloft for both stations:

• At 3,000 feet: 29022 - wind from 290° at 22 knots. Flying 120°, that’s roughly a direct crosswind. Minimal wind component. Groundspeed stays close to true airspeed.
• At 6,000 feet: 26018 - wind from 260° at 18 knots. That puts a headwind component on a 120° track - roughly 8–10 knots of effective headwind. Groundspeed drops below true airspeed.
• At 9,000 feet: 22012 - wind from 220° at 12 knots. Flying 120°, 220° is behind your left shoulder. That’s a tailwind component - roughly 6–8 knots added to groundspeed.

Same aircraft. Same engine setting. Same fuel load. At 3,500 feet you’re neutral. At 5,500 feet you’re fighting a headwind. At 7,500 feet a tailwind is working for you.

The pilot who checks this before the flight and climbs to 7,500 feet arrives with more fuel, in less time, and with a healthier reserve than the pilot who defaulted to 3,500 because it’s familiar. Altitude shopping is free, takes about three minutes during planning, and produces a measurable difference in the actual flight.

Why Does the Temperature Column Matter?

The temperature data in the winds aloft forecast feeds directly into your true airspeed calculation. Converting indicated airspeed to true airspeed requires both pressure altitude and outside air temperature. Your E6B or flight calculator app asks for both.

The standard atmosphere assumes a lapse rate of roughly two degrees Celsius per thousand feet. The real atmosphere is not always standard. If the forecast shows +15°C at 6,000 feet when standard would predict around +4°C, the air is warmer and less dense than the model assumes. Your true airspeed is higher than a standard calculation would give you, and your density altitude is higher than you might assume - both matter for performance.

The temperature column is also the foundation of icing awareness. Under VFR, student pilots should not be in icing conditions. But knowing how to read temperature aloft is a building block for instrument work. When temperatures approach 0°C or below at cruise altitude in the presence of visible moisture, that combination becomes significant. Build the habit of reading the temperature column now, every time.

How Do You Use Winds Aloft Across a Longer Route?

For a short hop, one station forecast may be sufficient. For a route spanning 200–300 miles, pull winds aloft data for several stations along the route. The Aviation Weather Center provides a map view showing wind direction and speed overlaid on the country at a selected altitude - a planning tool many student pilots never discover until an instructor points it out.

A frontal boundary sitting across your route can mean winds from the southwest at departure and from the northwest by the time you’re three-quarters of the way there. The effective wind component on the same leg changes character mid-flight. Knowing that in advance enables better altitude choices, smarter fuel stop decisions, and better go/no-go calls.

How Reliable Is the Winds Aloft Forecast - and What Do You Do When It’s Wrong?

The winds aloft forecast is a forecast. It is very good, but it is not guaranteed. Actual conditions can and do differ from what the product showed on the ground.

This is exactly why you write the forecast winds on your navigation log before departure. During the flight, when you check actual groundspeed against planned groundspeed, you have a reference point. If you planned for a 12-knot tailwind and you’re actually fighting an 8-knot headwind, the forecast was off by 20 knots. That’s not a crisis - but it means your fuel math needs revision, and the sooner you do that arithmetic, the more options remain available.

Catching that discrepancy early, while you still have multiple good alternates and a healthy fuel reserve, is what separates a managed situation from an emergency. The pilot who waits until fuel gauges force a decision is in a much harder position than the pilot who revised the plan 60 miles back.

Forecast accuracy by time horizon:

• Six-hour forecast - most reliable. Use this for a departure two hours from now.
• Twelve-hour forecast - accurate but beginning to degrade. Use this for evening-before planning, then recheck in the morning.
• Beyond 24 hours - treat as general guidance, not precision planning. Weather systems can shift faster than models anticipated.

If you planned the night before, pull the product again the morning of your flight. The atmosphere may have changed its mind overnight.

How Do You Build the Winds Aloft Forecast Into Your Routine?

Add a dedicated column to your navigation log for winds aloft. For each leg, record the forecast wind direction, speed, and temperature at your chosen altitude. During the flight, compare actual groundspeed to planned groundspeed at each checkpoint.

Notice when the two match. Notice when they diverge. Use that information to make real-time decisions about altitude, fuel stops, and routing. That active, in-flight weather monitoring is exactly what an examiner wants to see at the practical test - not a pilot who recited a list of weather products, but a pilot who uses the forecast to make decisions as conditions develop.

Key Takeaways

• Pull the winds aloft forecast for every cross-country. It directly determines whether your fuel math is accurate before you leave the ramp.
• Altitude shop every leg. Compare wind component at each legal altitude and choose the one that serves your route, terrain constraints, and fuel picture.
• Write forecast winds on your navigation log and use them in flight to validate groundspeed - catch discrepancies early, while options remain.
• Don’t skip the temperature column. It informs true airspeed corrections and density altitude awareness.
• On routes over 200 miles, pull data for multiple stations along the route - winds change character across fronts and geography.
• Recheck the forecast the morning of a flight planned the night before. The six-hour forecast is the most reliable for near-term departures.