In late January 2018 a huge snowstorm swept across Iran, causing major disruptions.
By Saviz Sehatkashani (ASMERC), Abolghasem Ghazanfari (IRIMO) and Jochen Kerkmann (EUMETSAT)
The snow started on 25 January, but peaked on 27 January with some areas of western and northern Iran having at least 20 cm. All the schools and both the airports in Tehran were closed.
The accumulated snow levels at Imam Khomeini and Mehrabad airports, from 27 to 29 January, were 80 cm and 30 cm respectively. The heavy snowfall was the result of the domination of high pressure extending zonally from Balkhash to the Aral Sea, with the core of 1050 hPa at surface level.
On the animated Meteosat-8 Water Vapour three hourly imagery (Figure 2) the development of the cyclonic system with the occluded front that passed over Iran on 27/28 January can be seen.
On 27 January, visibility reduced to just 100 m at Imam Khomeini and 300 m at Mehrabad airport. On 28 January visibility was still reduced — 400 m at Imam Khomeini and 200 m at Mehrabad.
The 30 cm recorded at Mehrabad was the second highest snowfall amount since the station was set up 60 years ago — beaten only by 40 cm in 1993.
In general, across the country 275 km of main roads and 489 km of cross-country roads struggled to keep open during the the snow and resulting blizzards. In order to try to reduce traffic problems, all government organisations started their working day two hours later than usual. Schools and universities in Tehran province were closed.
Despite the impacts of the snow, it was welcomed due to the low levels of precipitation the Tehran area had previously had during autumn and winter. It played a key role in calmness and happiness of Tehran residents' public opinion, particularly the children who got to play in it (see photo by Newsha Tavakolian).
The lying snow could still be clearly seen on the Meteosat-8 and 10 Snow RGBs on 2 February, 06:00 UTC (Figures 4 & 5). The snow-covered ground appears as orange on the RGBs.
First snow blankets Tehran, many other Iranian cities (IRNA)
North Iran gets massive snow dump (Strait Times)
Heavy Snow in Tehran Shuts Schools, Airports (Iran Front Page)