Weather forecasts

SportsTrackLive builds a full forecast page for any point on Earth — designed for free-flight pilots and outdoor athletes who need more than an icon and a temperature: wind at altitude, the convective layer, cloud cover by level, and how the models disagree with each other.

Opening a forecast

There are three ways in:

• From an activity page — the orange Forecast button next to Export opens the forecast for the activity's start location.
• From the map — click anywhere on an activity map: an animated cursor marks the point, and its tooltip "Forecast at this location" opens the forecast page for those exact coordinates.
• By URL — Google-Maps-style coordinates, straight in the address bar:

https://www.sportstracklive.com/weather-forecasting/@42.69,2.49

Nearby requests reuse the same forecast point (about 1 km — the grid size of the finest model), so repeated clicks around a takeoff share one page.

The page header

• If the point sits within 1 km of a known site (a locality with recorded activities), the site names the page — Pic Arnau, Tarerach - 42.69, 2.49 — followed by the ground altitude.
• Nearby sites appear as chips: name, distance from your point (in metres below 5 km) and ▲ site altitude. Each chip links to the site's activity page.
• The run caption tells you which model run you are looking at ("Run AROME HD 2026-08-10 14:00" — the estimated initialisation time of the run) and the model's ground elevation.

Seven forecast models

Switch model with one click — the active tabs only offer models that actually cover your point (AROME stops at the French borders; GFS and ECMWF cover the globe; ICON-MP2 appears where Météo-Parapente's fine European domain covers the spot).

Model	Provider	Resolution	Refresh	Range
AROME HD	Météo-France	1.3 km	every 3 h	3 days
AROME	Météo-France	2.5 km	every 3 h	3 days
ARPEGE	Météo-France	11 km	every 6 h	4 days
ICON	DWD	7 km	every 3 h	5 days
GFS	NOAA	13 km	every 6 h	5 days
ECMWF	ECMWF	25 km	every 6 h	5 days
ICON-MP2	Météo-Parapente	2.5 km	twice a day	4 days

AROME HD — the best of both worlds

The 1.3 km AROME HD feed only publishes surface fields. SportsTrackLive automatically merges its high-resolution surface data (wind, temperature, CAPE, precipitation) with the AROME 2.5 km vertical profile — the same approach the reference soaring sites use.

Runs are archived for 14 days: the Runs selector lets you reopen an older run and compare what the model believed yesterday with what it says now. Switching model or day never loses your place — the selected day, ceiling and palette carry over.

The time step: 1 hour, everywhere

A fine-mesh model such as AROME publishes its output hour by hour. That is the whole point of a fine mesh: at 1.3 km resolution, the valley breeze that picks up at 11:00 and the sea breeze that arrives at 16:00 are not the same phenomenon, and a 3-hour step flattens both.

SportsTrackLive shows that hourly step everywhere the model provides it — in the surface view, in the vertical cross-section, in the Stüve diagram. It is the data as published, with no downsampling, where other consumer services keep the hourly step for their paid tier and stop at 3 hours in the free one.

Why it matters in free flight

A flyable window often lasts less than three hours. On a 3-hour step it fits inside a single data point — you see that it was windy in the afternoon, not that it built from 15 to 35 km/h between 14:00 and 17:00.

Surface quick view

A meteogram of the coming days, hour by hour:

• Weather icons day and night — night icons show the actual moon phase.
• Temperature and feels-like, with a smooth temperature curve and the dew point curve behind the numbers.
• Rain (mm), wind and gusts on a colour ramp that saturates as it strengthens, and the wind direction arrows.
• A 1 h / 3 h step toggle (no page reload) and a Now button that jumps back to the current hour after you scrolled.

Vertical cross-section

The heart of the page — altitude rows from the ground up to a selectable ceiling (2000 / 3000 / 4000 / 5000 m, default picked from the day's thermal ceiling), hour columns:

• Wind arrows per cell, coloured by speed (hover for speed, direction, temperature and cloud cover at that level).
• The convective layer highlighted from the ground to the estimated thermal ceiling — computed by the dry-adiabatic method from the model profile. It is an estimate, not a direct model output, and is marked with a dashed ceiling line.
• Cloud cover as a grey veil in the cells, plus dedicated high / mid / low cloud bars.
• Header rows: sea-level pressure, precipitation, CAPE.
• Row scale of 100 m or 200 m, two palettes (classic soaring look, or a full colour ramp where the convective layer switches to a salmon wind ramp), and a dashed now marker.

Emagram

Where the cross-section shows a whole day at once, the emagram shows one hour in detail — the atmospheric sounding as pilots read it. The plot starts at sea level and climbs to about 5 500 m, whatever ceiling the cross-section is set to: the near-black slab at the bottom is the terrain itself, so you see at a glance how much relief sits under the profile.

Two curves carry it:

• the state curve — the air temperature the model reports — coloured by stability, segment by segment:
  • black — stable air: the air cools more slowly with height than both adiabats. Thermals are braked.
  • green — conditional instability: it cools faster than the saturated adiabat but more slowly than the dry one. Thermals can accelerate under the right conditions.
  • red — absolute instability: it cools faster than the dry adiabat (more than 9.8 °C/1 000 m). Thermals accelerate. You will mostly see it hugging the ground on sunny afternoons — that superheated surface layer is where thermals are born.
• the dew point (blue). The gap between the two curves is the humidity: close together means cloud, far apart a dry air mass.

The comparison against the saturated adiabat is done at each segment's own temperature and pressure — that rate swings from ~4 °C/1 000 m in warm low air to ~9 near −40 °C, so no fixed threshold could classify a profile honestly.

The orange band is the convective layer: from the ground up to the top of thermals, shaded like the cross-section's convective cells. Two named lines carry the numbers directly on the plot:

• Top of thermals — where a bubble leaving the ground at the model's own 2 m temperature (no artificial overheat) stops being warmer than the air around it. It is computed exactly like the cross-section's ceiling, so the two views always quote the same altitude.
• Condensation — where that bubble would cool to its dew point. When it condenses before meeting the state curve, the usable ceiling is the cloud base and the two lines merge: the climb continues inside the cumulus, which is not where anyone flies.

Blue day

No Condensation line means a blue day: the thermal dies dry, before any condensation. That is not missing data, it is the answer — the thermals are there, but nothing in the sky will mark them.

At night and in the early morning the top of thermals sits on the ground: a bubble that is never warmer than its surroundings does not climb.

The background carries the classic sounding guides: isotherms (the 0 °C one stands out), dry and saturated adiabats, and mixing-ratio lines. They are deliberately faint — the coloured state curve must read first. The wind arrows per level, on the right, are the same as the cross-section's: same length, same weight, same meaning.

The temperature axis is fixed, −15 °C to 40 °C, on every hour of every day — so two emagrams can be compared at a glance. It only stretches when a curve would actually leave the frame.

The hour wheel under the plot covers the whole day, 0 h to 23 h. Switching is instant — every profile is already loaded. The legend sits below it.

Why the axes lean

An emagram is not a plain altitude-versus-temperature chart: the isotherms are deliberately slanted. That spread, called skew-T, pulls apart curves that would otherwise crowd onto a vertical line, and keeps the state curve readable across 5 000 m of climb.

Model comparison

One chart, all covering models: surface wind, hour by hour, one line per model for the selected day. Where the models agree you can trust the picture; where the lines split, the day is uncertain — check back after the next runs.

When the forecast point is linked to a live weather beacon, the chart also shows the beacon's readings and each model tab displays its mean absolute error (± km/h) against the beacon over the last hours — so you know which model to believe today. On the cross-section's ground row, a model value that clearly deviates from the live reading is struck through with the beacon's real value shown in violet.

Stüve diagram

For pilots who read soundings: a multi-day time × pressure section (1000 → 500 hPa):

• Temperature field in 5 °C bands (pastel), isotherms every 5 °C with the 0 °C isotherm in white — spot the freezing level at a glance.
• Standard wind barbs (knots: half barb 5, full 10, pennant 50) per pressure level.
• Night bands on the hour axis, day separators, and the same 1 h / 3 h toggle.

Sharing a forecast

Forecasts are for signed-in members. But a pilot planning a flight often needs to show their page to someone without an account — that is what the Share button does, beside the site name and in the bottom bar.

It mints a link that opens the forecasts without an account, for as long as it lasts:

Account	Link lifetime
Free	48 hours
Premium	7 days

Two guarantees worth knowing:

• The link opens only the page you shared. It grants nothing else — if it spreads, it never becomes a skeleton key.
• It expires. After that the recipient gets the public preview of the place and an invitation to sign up. Just share a fresh link.

The Copy link button next to it puts the address on the clipboard — handy when the system share menu offers no copy option, which happens on desktop.

Opening straight in the app

The shared link uses an /open/weather/… address. On a phone with the SportsTrackLive app installed, it opens directly on the right page instead of the browser. Without the app, the same link shows the web page: it is never a dead end.

A forecast stays a forecast

The decision to fly is yours

Everything this page shows — wind, thermal ceiling, cloud base, emagram, cross-section — comes from numerical models. A model simulates the atmosphere; it does not observe it. However fine the mesh, a forecast remains a probability, not a certainty.

SportsTrackLive provides this data for information and flight preparation. It replaces neither the official bulletins of your national weather service, nor NOTAMs and aviation weather bulletins, nor your own judgement in the field. The decision to launch, continue or land remains entirely yours, under your sole responsibility.

A few limits worth keeping in mind:

• Thermal ceiling and cloud base are computed values, not direct model output. They rest on an assumed parcel temperature excess; the actual day can depart from it noticeably.
• Local terrain escapes the models. Even at a 1.3 km mesh, a windy corridor, a valley breeze or a venturi at a col are not resolved. Local knowledge and live beacons remain irreplaceable.
• Uncertainty grows with lead time. A 5-day forecast gives a trend; only the next 24 to 48 hours deserve to be trusted for a flight.
• Models are wrong, and not all in the same way. That is exactly why the page offers the model comparison and the mean error against live beacons: when the lines split, the right reading is "uncertain day", not "let us pick the most favourable model".

Good to know

• Pages refresh automatically as the models publish new runs.
• All times are local to the forecast point.
• The same forecasts are built into the mobile app — tap any point of the 3D map or use the weather button for your own position.