Paramotor Weather FAQ

What is the Send Score?

The Send Score is a 0 to 10 summary of the forecast for each hour. It starts at 10 and takes points off for: forecast wind and gusts at 10 meters (33 ft) compared with your limits, wind shear between the surface and about 600 ft and in deeper layers above that, forecast visibility under 3 miles, chance of rain, how fast the temperature drops with height up to about 5,000 ft, and CAPE (instability).

Labels: 8.5 and up is Great, 7 to 8.4 is Good, 5 to 6.9 is Marginal, and under 5 is Poor. A rain chance over 50% sets the hour to 0 and marks it NO-GO. CAPE of 4,000 J/kg or more also drops the score to 0. Wind and gusts can take off at most 6 points, so a very windy hour can still show a middling score. Always look at the actual wind numbers, not just the score. Tap the ⓘ next to any score for the breakdown.

The score only knows what the forecast model knows. It can't see turbulence from trees, buildings or terrain at your field, individual thermals, rotor, gust fronts, or storms the model misses. It is not a safety rating. A high score means the forecast looks favorable, not that the air will be smooth or safe.

What is a good wind speed for flying a paramotor?

There is no single safe number. What works depends on your wing, your weight, your experience, your launch area and how steady the wind is. Part 103 doesn't set a wind limit; it's your call. If you're newer to the sport, set your limits with your instructor.

Paramotor Winds lets you set your own max sustained wind and max gust in the settings. The defaults (9 mph sustained, 12 mph gusts) are Alex's personal settings, not a recommendation for you. The grid colors and Send Score are judged against whatever limits you set.

How steady the wind is matters as much as its average. The force of the wind on you and your wing rises with the square of its speed, so 20 mph pushes about four times as hard as 10 mph, and a gust from 8 to 14 mph roughly triples the push.

The forecast wind is a model value for the hour over a grid area at 10 meters (33 ft), not a measurement at your field. Forecast gusts are the model's highest gust over the past hour. Wind at your launch can be stronger, gustier or from a different direction, especially near trees, buildings and terrain.

What do AGL and MSL mean?

AGL means above ground level, and MSL means above mean sea level. Paramotor Winds labels heights as AGL by default, and you can switch to MSL in the settings.

The “0 ft” row shows the model's wind at 10 meters (33 ft). The rows above it are estimates: the app takes the model's winds at 80 meters and at a series of pressure levels, works out how high each pressure level sits above the ground elevation for your location, and fills in the heights in between. Pressure-level heights shift from hour to hour, and the ground elevation comes from a 90 meter terrain model that can differ from your exact launch spot. Treat the rows as a forecast of the general wind profile, not exact winds at exact heights.

What is a TFR, and how do I check for one?

A TFR (temporary flight restriction) closes a piece of airspace for a set time. A common one covers major sporting events: during regular or postseason MLB, NFL and NCAA Division I football games at stadiums with 30,000 or more seats, plus certain NASCAR and IndyCar races, flight is prohibited within 3 nautical miles and up to and including 3,000 ft AGL, from 1 hour before the scheduled start until 1 hour after the event ends.

The TFR button in Paramotor Winds shows TFRs from the FAA's TFR system on a map, with active ones in red and upcoming ones in orange. Stadium TFRs are marked (est.) because the app estimates them from public game schedules. Those estimates can miss events or end too early, for example when a game runs long.

Paramotor Winds is not an official source. Before every flight, check current TFRs and NOTAMs at tfr.faa.gov or get an official briefing from Flight Service at 1-800-WX-BRIEF (800-992-7433).

What is a METAR?

A METAR is an official surface weather observation from an airport weather station, routinely issued near the top of each hour, with special reports (SPECI) in between when conditions change. Paramotor Winds shows the latest report from the station nearest you, in plain English with the raw report underneath.

A METAR describes conditions at that airport at the time of the report. It isn't a forecast, and conditions at your field may be different, especially if the station is far away or the terrain is different.

What are winds aloft, and why are they stronger than surface winds?

Winds aloft are the winds at the heights you actually fly. Near the ground, friction from terrain, trees and buildings slows the wind down. That friction fades with height and becomes small above the lowest few thousand feet; strong wind and rough terrain push it higher. So winds aloft are often stronger than what you feel on the ground.

The direction can change with height too. Friction turns the surface wind toward lower pressure, so in the Northern Hemisphere the wind often turns clockwise (veers) as you climb. That's a tendency, not a rule: terrain, fronts and sea breezes can make the wind behave differently.

Changes often show up aloft before they reach the surface, so stronger winds a few thousand feet up can be a sign the surface wind will pick up once the day starts mixing. In Paramotor Winds, everything above the lowest rows is a model estimate, not a measurement.

What is the best time of day to fly a paramotor?

Often the first couple of hours after sunrise and the last couple of hours before sunset, when winds are typically lighter and thermals weaker. That's a common pattern, not a promise. Fronts, sea breezes, storms and terrain can override it.

On a typical sunny day over land, the air is calmest around sunrise. As the sun heats the ground, thermals develop, usually by late morning, and build into the afternoon. That mixing brings faster wind from aloft down to the surface, so surface wind often peaks in the afternoon. Convective turbulence is usually most active on warm afternoons. As heating fades, wind and thermals usually ease, sometimes quickly, though some ground keeps releasing heat into the evening.

Part 103 allows flying only between sunrise and sunset, plus up to 30 minutes before sunrise and after sunset with an anticollision light in uncontrolled airspace. The “Daytime hours only” filter in Paramotor Winds shows from about an hour before sunrise to an hour after sunset, which is wider than that legal window.

What is wind gradient?

Wind gradient is the change in wind speed with height near the ground. The wind is slowest right at the surface and increases with height, often quickly in the lowest part of that layer.

It matters most when landing. As you descend from faster wind into slower wind, your airspeed can drop. A wind shadow behind a tree line, building or hill makes the change sharper and less predictable. In any real wind, avoid landing in the lee of obstacles.

What is wind shear?

Wind shear is a change in wind speed or direction over a short distance, up and down or side to side. Where layers of air move differently, the boundary between them can be turbulent. Strong shear often occurs across temperature inversions, along fronts and sea breeze fronts, and in thunderstorm outflow.

The most dangerous low-level shear comes from microbursts and gust fronts near showers and thunderstorms. The FAA describes microburst shear as extremely hazardous to all types of aircraft, and microbursts can come from clouds with little or no rain reaching the ground.

The Send Score compares the model's 10 meter wind with its winds at 80, 120 and 180 meters (about 260 to 590 ft), plus two deeper layers above that, and takes off points for big changes in speed or direction. Forecast models smooth out shear, so no shear penalty doesn't mean no shear.

What causes gusts, and what is gust spread?

Gusts are short bursts of faster wind caused by turbulent eddies: wind tumbling over obstacles, thermals mixing faster air down from aloft, and shear between layers. On windy, thermal days, the air sinking to replace rising thermals brings faster wind down to the ground. Those are the dark ripples you see racing across a pond or a field of grass.

Gust spread is the difference between the gusts and the sustained wind, and a big spread means uneven air. In Paramotor Winds, the score loses points as sustained wind approaches your max, as gust spread grows past 4 mph, and when gusts go over your max gust. Forecast gusts are a model estimate; real gusts at your field can be stronger.

How is wind direction reported?

Wind is named for the direction it blows from, so a north wind blows from the north. Aviation reports give it in degrees: 360 is north, 90 is east, 180 is south and 270 is west. Speeds in aviation reports are in knots, and 1 knot is about 1.15 mph.

Written reports and forecasts, such as METARs and winds aloft forecasts, use true north. Spoken airport broadcasts (ATIS, and ASOS or AWOS radio or phone) use magnetic north. In the Paramotor Winds grid, each arrow points the way the wind is blowing toward.

What is rotor, and how far from trees and buildings should I stay?

Rotor is a rolling eddy of air that can form downwind of obstacles such as hills, ridges, tree lines and buildings. More generally, the churned-up air behind obstructions is called mechanical turbulence. How strong it gets and how far downwind it reaches depends on wind speed, surface roughness, the size and shape of the obstacle, and how stable the air is. In stable air the eddies can carry a long way before they die out.

Rotor is dangerous because it can feel like a steady breeze, and behind a hill or tree line the wind can even blow the opposite way from the real wind. Pilots have launched into rotor thinking it was the true wind. Compare the windsock with the forecast and the winds aloft, and look at what the wind is doing upwind of obstacles. If you suspect rotor, don't launch there. In the mountains, rotor under mountain waves can be severe to extreme.

There is no proven formula for a safe distance behind an obstacle. Give obstacles as much room as you can, more in stronger wind, and treat the downwind side of anything big as suspect.

How can I tell if the air is turbulent before I launch?

Watch things that move with the wind: trees, tall grass, water, flags, windsocks and smoke. A windsock or flag that keeps swinging or snapping, or smoke that breaks up quickly, points to turbulent air near the ground.

Clouds help too. Cumulus clouds mark rising air, with turbulence below and in them. Near mountains, smooth lens-shaped (lenticular) clouds or ragged rotor clouds point to mountain waves and rotor.

These clues have limits. When the air is too dry for clouds, thermals give little or no warning until you fly into them, and a calm windsock on the ground tells you little about the air a few hundred feet up.

What are thermals, and why do paramotor pilots avoid them?

A thermal is a rising bubble or column of warm air over ground the sun has heated. Bare ground, plowed fields and pavement heat faster than water or vegetation, so thermals can vary a lot over short distances. For every rising current there is sinking air nearby.

Flying through thermals often means lift, then sink, then lift again. Strong thermals can cause serious wing problems, especially for newer pilots, which is why many motor pilots avoid mid-day flying. When the air is too dry for clouds, thermals give little or no warning.

Convective turbulence is usually most active on warm afternoons with light wind. Waiting for the sun's heating to taper off later in the day is a common way to avoid the worst of it.

What is lapse rate?

Lapse rate is how fast the temperature drops as you go up. Rising air that isn't forming cloud cools about 3°C per 1,000 ft (about 5.4°F, or 9.8°C per km). Once it is forming cloud it cools more slowly, roughly 1.2°C to 3°C per 1,000 ft depending on its temperature. The standard atmosphere uses about 2°C per 1,000 ft, but real days vary a lot.

Comparing the actual lapse rate with those numbers tells you how the air will behave. If the air cools more slowly than the cloud-forming rate, it is absolutely stable. If it cools faster than the dry rate, it is absolutely unstable. In between, it is conditionally unstable: stable for clear air, but unstable once rising air becomes saturated and forms cloud.

The Send Score compares the model's 2 meter temperature with its temperature about 1,500 meters (4,900 ft) up. It takes off 1 point at 6°C per km or more and 2 points at 7°C per km or more. That's a rough read on mixing over a deep layer. A strongly heated layer near the ground can be bumpy even with no lapse-rate penalty.

How can I tell stable air from unstable air?

Signs of unstable (thermal, bumpy) air: building cumulus clouds, smoke that rises high, dust devils, gusty winds, and good visibility. Signs of stable (smooth) air: flat layer clouds, smoke that rises and then spreads out flat, steady winds, fog, and haze.

A clear night followed by a clear morning often leads to an unstable afternoon. Overcast days tend to be more stable.

These are clues, not proof. Stable air has fewer thermals, but it can still have shear at inversions, and turbulence behind obstacles lasts longer in stable air.

What is a temperature inversion?

An inversion is a layer where the temperature increases with height instead of decreasing. Inversions are very stable, so there is little turbulence inside them, and they put a lid on thermals.

They often form near the ground on clear nights with light wind, along fronts, and when cold air pools in valleys. Strong wind shear often occurs across an inversion, for example calm air at the surface under much stronger wind above, which can make the air rough as you climb or descend through it.

What is CAPE?

CAPE (convective available potential energy) measures how much energy rising air could gain from instability, in J/kg. Higher CAPE means stronger potential updrafts and thunderstorms if something lifts the air.

CAPE alone doesn't tell you whether storms will form or how rough the air will be. A capping inversion can keep storms from forming even with high CAPE, and low CAPE doesn't mean smooth air.

In Paramotor Winds, the hour details describe CAPE above 100 J/kg as a likelihood of unstable air, 1,000 and up as a strong likelihood, and 3,500 and up as extremely unstable. The Send Score starts taking points off above 600, takes off up to 4 points by 2,500, and drops the hour to 0 at 4,000 or more. These are this site's settings, not official thresholds.

What is density altitude, and how does it affect a paramotor?

Density altitude is how high the air “acts” based on how thin it is. Hot temperatures, low pressure and a high launch elevation all raise it. Humidity matters much less.

Higher density altitude means less engine power, less propeller thrust and less lift from your wing. Expect a longer, faster takeoff run and a weaker climb on hot days and at high fields.

How close is too close to a thunderstorm?

No distance guarantees safety. Turbulence is present in every thunderstorm. The FAA notes that turbulence has been found up to 20 miles from a severe storm, and recommends staying at least 20 miles from any thunderstorm identified as severe. Storms can grow and move quickly, so if storms are nearby or building, stay on the ground.

Thunder can usually be heard only about 10 miles away. The National Weather Service says if you can hear thunder, you are likely within striking distance. To estimate how far away lightning is, count the seconds from flash to thunder and divide by 5 for miles.

The FAA advises against taking off or landing with a thunderstorm approaching, because a sudden gust front can cause loss of control. Squeezing in a flight before a storm arrives has a bad track record.

Paramotor Winds shows active National Weather Service alerts, and the Send Score drops for high rain chances and high CAPE. Neither will catch every storm, especially ones that pop up between forecast updates. Check current radar and official weather before flying, and keep watching the sky.

What is a gust front?

A gust front is the leading edge of gusty surface winds from thunderstorm downdrafts. Cold air from the storm hits the ground, spreads out and pushes ahead, bringing a sudden wind shift, a jump in speed and severe turbulence. A shelf cloud or roll cloud, or a line of blowing dust, sometimes marks it, but often there's no visible sign.

Gust fronts often run far ahead of the rain, up to 15 miles according to the FAA, and sometimes farther. They can reach you before any rain does.

Microbursts are small, intense downdrafts that spread out violently at the ground. They can come from heavy rain or from weak-looking showers with little or no rain reaching the ground, including virga (rain that evaporates before it lands). The FAA notes that surface winds in a microburst can reach 45 knots and that it keeps strengthening for about 5 minutes after it hits the ground.

What do clouds tell you about flying weather?

Clouds show what the air is doing. Puffy cumulus mean rising air and instability, and the faster and taller they build, the stronger the convection. Towering cumulus and cumulonimbus with anvil tops warn of violent turbulence. Flat layer clouds usually mean stable air.

Some cloud patterns often come before weather changes: a thin, high cirrostratus veil can come 12 to 24 hours ahead of rain; clouds that steadily lower and thicken often mean a warm front; and altocumulus on a warm, humid morning can point to afternoon thunderstorms. These are general tendencies, not forecasts.

Dry thermals, shear and rotor can be invisible in clear air, so a clear sky doesn't mean smooth air.

What is a sea breeze?

During the day, land heats up faster than water. Cooler air from the water flows inland at the surface, with a return flow aloft. Sea breezes (and lake breezes) are most common on calm, sunny summer days.

The leading edge, the sea breeze front, brings a wind shift and can trigger showers and thunderstorms, especially where breezes from opposite coasts meet over a peninsula. Expect shear and turbulence along it.

Behind the front, the marine air is usually stable and smoother, but wind speed and direction can keep changing through the day. The larger-scale wind strongly affects whether, when and how far inland a sea breeze forms.

What does a falling barometer mean?

A barometer measures air pressure. A rapid fall in pressure often signals an approaching storm or front, and steady or rising pressure often goes with settled weather.

Pressure trends are a rough clue, best combined with the forecast, changes in the wind and what you see in the sky. Rules of thumb that pair pressure with wind direction don't replace a current forecast.

What visibility do I need to fly a paramotor under FAR 103?

14 CFR 103.23 sets flight visibility and cloud clearance by airspace. Class G (uncontrolled), 1,200 ft or less above the surface: 1 statute mile and clear of clouds. Class G more than 1,200 ft above the surface and below 10,000 ft MSL: 1 mile, and 500 ft below, 1,000 ft above and 2,000 ft horizontally from clouds. Class C, Class D, and Class E below 10,000 ft MSL: 3 miles, and 500 ft below, 1,000 ft above and 2,000 ft horizontally from clouds. Class B: 3 miles and clear of clouds. At or above 10,000 ft MSL (Class E, or Class G more than 1,200 ft above the surface): 5 miles, and 1,000 ft below, 1,000 ft above and 1 mile horizontally from clouds.

Under 103.17 you may not fly in Class A, B, C or D airspace, or in Class E airspace designated for an airport, without prior authorization from the ATC facility for that airspace. Under 103.11 you may fly only between sunrise and sunset. Twilight flying, up to 30 minutes before sunrise and after sunset, requires an operating anticollision light visible for at least 3 statute miles and is allowed only in uncontrolled airspace.

These are legal minimums, not a sign that conditions are safe, and this is a summary, not the full rule. Read the current text of 14 CFR Part 103. The Send Score lowers the score when forecast visibility drops below 3 miles, but it doesn't know your airspace and can't tell you whether you meet these rules.

Who is Alex Lang?

I'm a paramotor pilot based in the Atlanta area. I run my own accounting firm, Lang Accountants & Advisors, and I'm passionate about flying. I built Paramotor Winds as a pilot, for pilots.

Follow along on Instagram at @alexlang14.