The technological and intelligence war was also escalating. The RAF had been quick to discover "Knickebein" and effectively counter it. However, "X-Verfahren" systems in use among the pathfinders and some of the German bomber units were not disrupted. For much of the war 80 Wing believed their counter-efforts had affected the German navigational aids. They did however, solve the basics of "Y-Verfahren" but it would take two more months to counter the former aid. Operations were reduced in January due to the British weather. All groups were involved in remaining operations to Bristol on 3/4 January 1941, Manchester on 9/10 January, Portsmouth on 10/11 January and London the following night. Attacks on Avonmouth on 16/17 and Swansea on 17/18 January were the first to these targets. Records show that in the Portsmouth operation 19 of II./KG 55's He 111s dropped 18 LC 50 flares, eight SC1800, seven SD1400 ("Sprengbombe Dickwandig" bombs which had some penetrative power for armour-piercing purposes) and seven SC1000 bombs. Severe weather shut down II./KG 55's operations at its Chartres airfield until March 1941. This was the case for III./KG 55 at Villacoublay. III./KG 55 was grounded in Paris.