Weather and snow guns

Too warm for guns on all 15 slopes now. First cold spell: Leonid Tyagachev Ski Club, Shukolovo, from 7 November, 07:00, 4 h down to −2.2°.

Can snow be made on the 15 slopes of Moscow and the region right now, and when is the next cold night? Guns depend on the wet-bulb temperature: air temperature and humidity together.

Gun calculator Pro view adds air temperature, humidity, wind, chance, hourly table, formulas and the gun catalogue.

All slopes now

SlopeGun nowWet bulbAir, humidity, windNext 7 daysWorth starting?
Leonid Tyagachev Ski Club, Shukolovo Cannot run +0.1° +0.2° · 97 % · 4 m/s Weak: 4 h from 7 November, 07:00
Sorochany Cannot run 0.0° +0.1° · 98 % · 4 m/s Weak: 4 h from 7 November, 07:00
Spas-Kamenka Cannot run +0.1° +0.2° · 97 % · 4 m/s Weak: 4 h from 7 November, 07:00
Stepanovo Cannot run 0.0° +0.2° · 97 % · 4 m/s Weak: 4 h from 7 November, 07:00
Tseleevo Cannot run +0.1° +0.2° · 97 % · 4 m/s Weak: 4 h from 7 November, 07:00
Volen Cannot run 0.0° +0.2° · 97 % · 4 m/s Weak: 4 h from 7 November, 07:00
Yakhroma Park Cannot run 0.0° +0.2° · 97 % · 4 m/s Weak: 4 h from 7 November, 07:00
Loza, Sergiev Posad Cannot run +0.1° +0.3° · 96 % · 4 m/s Weak: 3 h from 7 November, 09:00
Vorobyovy Gory / Sparrow Hills Cannot run +0.7° +1.0° · 95 % · 4 m/s Weak: 1 h from 7 November, 10:00
Olimp, Kolomna Cannot run +1.2° +1.5° · 95 % · 4 m/s Weak: 8 h from 7 November, 18:00
Freestyle Park, Dzerzhinsky Cannot run +1.0° +1.5° · 92 % · 4 m/s No window in 7 days
Guy Severin Ski Club, Chulkovo Cannot run +0.9° +1.3° · 94 % · 4 m/s No window in 7 days
Kant, Nagornaya Cannot run +0.7° +1.0° · 94 % · 4 m/s No window in 7 days
Lata Trek, Krylatskoye Cannot run +0.8° +1.2° · 92 % · 4 m/s No window in 7 days
Lisya Gora, Balashikha Cannot run +0.8° +1.1° · 95 % · 4 m/s No window in 7 days
  • Excellent, −7° and colder
  • Good, −4° to −7°
  • Marginal, −2° to −4°
  • Limit, −1° to −2°
  • Too warm

This shows what the weather allows, not whether guns are running. Operators decide by water, power and schedule.

Percent of the gun’s top water flow, our estimate. Each day is four blocks: night, morning, afternoon, evening.

Yes means at least 6 hours in a row at about 30 % or more within three days. Our rule of thumb; the operator decides.

Forecast for 05:00 Moscow time, MET Norway.

Wet bulb on one chart

+4°0°−2°−4° 07.1108.1109.1110.1111.1112.1113.11
Wet bulbAir Grey lines are the other slopes. Below the −2° line guns can work. Steps are hourly for about two days, then six-hourly.

Guns here: Leonid Tyagachev Ski Club, Shukolovo

16 snow machines, types not split. Make: TechnoAlpin TR10 AM × 6.

3 more announced.

LOMOSREG, анкета клуба Л. Тягачёва

Checked 6 November · Leonid Tyagachev Ski Club, Shukolovo

Seven days on this slope

DayColdest wet bulbHours for gunsChanceSnow, one fan gunSnow, all gunsWater, all guns
6 November−1.0°020 %———
7 November−2.2°556 %40 m³646 m³429 m³
8 November−0.7°021 %———
9 November+2.0°04 %———
10 November+0.3°019 %———
11 November−1.5°043 %———
12 November−0.8°035 %———
13 November+3.3°06 %———

Upper bound: every gun at reference flow with enough water and pumps. Real output is lower.

Next 48 steps

Gun calculator

Enter the gun and the weather. The box shows how much snow it lays per hour and per night, and at what wind.

With nozzles and bore filled in, top flow is computed from them: Q = n × 0,7 × A × √(2Δp/ρ).

Result

— m³Snow per hour

— m³Snow for the shift

Gun works at
— %
Wet bulb
—
Water per shift
— m³
Layer on the area
— cm
Energy, guns only
— kWh
Snow density
— kg/m³
Lost to air and drift
— %

At what wind

WindSnow per hourPlume driftAdvice

An estimate for planning, not a manufacturer’s figure. The gun’s own chart beats this calculator. Assumptions are listed below.

How a gun makes snow

123456
  1. Water under pressure
  2. Compressed air
  3. Nucleators: ice seeds
  4. Nozzles: fine droplets
  5. Fan throws the plume
  6. Droplets cool in flight by evaporating, so the wet bulb decides

Hours for guns over ten winters

  • −2°
  • −4°
  • −7°

Average hours per month at or below each wet-bulb limit, Dmitrov district, winters 2016/17 to 2025/26. ERA5 reanalysis through Open-Meteo, computed by us.

WinterFirst 24 h in a rowHours Nov–Dec
2016/1731 October 20161055
2017/1826 October 2017602
2018/1930 October 20181024
2019/2031 October 2019420
2020/2117 November 2020755
2021/2210 November 2021828
2022/2315 November 20221036
2023/2425 October 2023885
2024/256 November 2024725
2025/2616 November 2025361

Formulas and assumptions

Wet bulb: psychrometric equation solved by bisection with Magnus saturation pressure, sea-level pressure from the forecast.

Snow = water × (1 − losses) × 1000 / density. Water = top flow × min(flow share, √(p / p top)).

Losses: 30 % + 2 × air °C, kept to 7–35 % as in Davos; 6 points less for fan guns; plus 1.5 points per m/s above 2 m/s. The last two are our assumptions.

Wind limits, our assumption: fan guns drift above 6 m/s, stop above 10; lances drift above 4, stop above 7. Operators report trouble from gusts of about 9 m/s; lances are more sensitive. Drift = wind × flight time, 5 s for fans, 7 s for lances.

Water temperature: TechnoAlpin’s rule of thumb is that 4 °C colder water equals 1 °C colder wet bulb. The calculator counts from 2 °C water; the forecast tables do not use it.

Cooling towers: a tower cools water towards the wet bulb and never below it, so it works best on the same dry cold nights as the guns. TechnoAlpin gives 30–90 l/s of flow at 15–45 kW depending on the model. Enter the water temperature after the tower in the calculator.

Chance: normal spread around the forecast, 1 °C now plus .35 °C per day. MET Norway gives no spread for this area, so this is our assumption, not a model output.

Reference guns where the make is unknown: fan 640 l/min, lance 120 l/min.

Flow share by wet bulb, our fit

−1.0°5 %
−2.0°13 %
−4.0°30 %
−7.0°62 %
−10.0°88 %
−12.0°100 %

Density, kg/m³

−2.0°500
−4.0°470
−7.0°430
−10.0°400
−15.0°370

Gun catalogue

GunTypeTop flow, l/minMaker’s snow, m³/hPressure, barPower, kWNozzles in useStart
Demaclenko Titan 4.0 Fan gun7201208–502384-1°
Demaclenko Ventus 4.0 Blizzard Fan gun540908–502064-1°
Demaclenko Evo 3.0 Fan gun432728–5016,245-1°
TechnoAlpin TR10 Fan gun757 · flow estimated—8–4023,324-1°
TechnoAlpin TR9 Fan gun568 · flow estimated—8–4019,518-1°
Supersnow 900 Automatic Fan gun6451058–4022120-1°
Supersnow 700 A SE Fan gun480808–401790-1.5°
Supersnow 600 M Fan gun480788–4018,590-1.5°
MND SUFAG Peak Plus Fan gun640968–4026,5310-0.5°
MND SUFAG Super Access Fan gun560818–4023300-0.7°
Экосистема ESG, 36 м³/ч Fan gun600908–16——-2°
Supersnow VIRGA Lance330608–402,212-1.5°
TechnoAlpin V3ee Lance120—8–402,2—-2°
HKD Impulse Lance303—13–40——-2°

TechnoAlpin does not publish top flow in these sources: 757 l/min comes from a SAM figure for the TF10, TR9 is scaled by nozzle count.

Why a gun looks at the wet bulb, not the thermometer

A droplet from a gun loses heat by evaporating, and dry air takes more of it. At −1 °C and 70 % humidity the wet bulb is −2.6°, enough to start. At the same −1 °C and 97 % it is −1.2°, and the gun stays off. Air temperature alone cannot tell the two nights apart.

Makers name a start between −0.5 and −2.5 °C wet bulb, but at the start a gun passes only a trickle: the MND Peak Plus runs from 50 of 640 l/min. A Russian maker writes that near −4 °C a gun gives at most 20–30 % of its top output. That is why this page treats −2 °C as the working line and shows the percent.

Not all water reaches the run. In twelve field tests near Davos, 7–35 % of it was lost, 21 % on average, and losses grew with air temperature. The snow that landed weighed 442 kg/m³ on average. So one cubic metre of water gives roughly two cubic metres of snow: the Krasnaya Gorka complex reports 40 m³ of water to 80 m³ of snow per machine, TechnoAlpin quotes 2.5.

How many gun hours a Moscow winter gives

Over ten winters the Dmitrov district averaged 280 hours at −2 °C wet bulb or colder in November and 489 in December, but the spread is wide: 361 hours for November and December together in 2025/26, 1055 in 2016/17. The first full day below the line came between 25 October and 17 November. Central Moscow differs little: 264 November hours.

TechnoAlpin counts about 1,000 m³ of water for a 30 cm base on one hectare. By our estimate one fan gun at −7 °C wet bulb and a light wind passes 23.8 m³ an hour, so that base takes 40 gun hours. Four guns would need about 10 hours: four nights of 12 hours fit an ordinary December, but only just a warm one like 2025/26.

Fleets differ. By operators’ forms Volen and Stepanovo together report 17 guns and 49 lances with 9 more planned, Sorochany 36 machines, the Tyagachev club 16, Freestyle 12 guns and 3 lances, Kant 12. Even so, in January 2025 Volen had snowmaking capacity for about half of its 14 runs: pumps, water and cold hours limit a slope before the number of guns does.

Public tenders give a price scale. Moscow’s Yauza Park tendered a fan snow machine with a built-in pump at a starting price of 6.05 million roubles in December 2025, a Moscow district office tendered a pump station with snow machines at 18.8 million in October 2026, and Mari El tendered one snow machine at 7.3 million in March 2026. Those are starting prices, not contract totals.

Questions

Can snow be made at 0 °C?

Yes, if the air is dry: at 0 °C and 30 % humidity the wet bulb is −4.1°. In damp weather no, whatever the thermometer says.

Does a cold night mean the slope is open?

No. This page shows what weather allows, not what an operator did. Check the season page and the operator.

What does a gun at 30 % mean?

It can take about a third of its top water flow without producing slush, so it makes about a third of the water into snow per hour compared with a very cold night.

Sources

Where to ski today