Snow Production. Valgrande-Pajares, stopped on 26 April 2023

Wet bulb temperature (Tw) WRF model and observation

Optimal temperature
Marginal temperature
Snow production not advised
Wet-bulb temperature at 1375 m WRF Model 1. Feb. 18, 2024, midnight
Wet-bulb temperature at 1620 m WRF Model 1. Feb. 18, 2024, midnight
Wet-bulb temperature at 1870 m WRF Model 1. Feb. 18, 2024, midnight
Wet-bulb temperature at 1375 m WRF Model 2. Feb. 18, 2024, midnight
Wet-bulb temperature at 1620 m WRF Model 2. Feb. 18, 2024, midnight
Wet-bulb temperature at 1870 m WRF Model 2. Feb. 18, 2024, midnight
Wet-bulb temperature Observatorio AEMET at 1480 m. March 3, 2024, noon

Current values:

Model 1: T = 7.9°C, RH = 48.9%

Model 2: T = 5.4°C, RH = 70.5%.

Aemet (last observation, 12:00): T = -0.8°C, RH = 99.0%

 


Tw base from -48 to +72 hours

 


Wet-bulb temperature calculator



 

 


Additional information

 

With the appropriate wether conditions snow production is more efficient and the result more pleasant for the skier.

Below certain levels of temperature and humidity snow production costs are reduced and snow quality improves. The best weather variable to determine this threshold is the wet-bulb temperature (Tw).

Two upper rows of dials show Tw estimated from a high resolution weather model, the WRF, with slightly different parameters. The third row is Tw calculated from a nearby weather station. Measured data should be close to reality, but in fact there may be discrepancies due to maitenance, wind, snow reflected solar radiation affecting the instrument shields, etc. Color markers allow a rapid evaluation of favourable conditions for snow production.

The last line chart shows data from previous days together with a 72 h forecast. This alows evaluating the performance of the models and their reliability for coming days. The color background makes an easy identification of favourable conditions.

The wet-bulb and dew point calculator is an useful tool for data measured on site. Calculations are based on Stull (2011), which are valid for usual conditions at many resorts. In case of extreme cold or low humidity you may check the US National Weather Service calculator.

Stull, Wet-Bulb Temperature from Relative Humidity and Air Temperature. Journal of Applied Meteorology and Climatology, 2011, 50(11),2267-2269