British Airways A321 G-MEDG operating BA237 London Heathrow – Moscow Domodedovo (depart London Heathrow 16th January) diverted to Riga in the early hours of this morning due to weather at Moscow. The aircraft then returned Riga – London Heathrow still using the BA237 callsign. As a result BA236 Moscow Domodedovo – London Heathrow was cancelled.