When the bomb group arrived overseas, a weather station was already in operation at Grafton Underwood under the direction of Captain Martin of the 18th Weather Squadron. Within a short time, the duties were taken over by Captain Alfred R. Westfall, the Group Weather Officer who had come over with the 384th, but was not previously identified with the weather squadron. Captain Henry G. Horak became the head of the 18th Weather Squadron in October 1943, continuing until late December 1944, when Captain John P. Scarbrough took over the command. Captain Scarbrough remained in that capacity until the end of the European war.
The 18th Weather Squadron provided detachments at each base in England, typically identified with the number of the AAF station to which they were assigned. The detachment trained with the RAF to familiarize forecasters and observers with European weather patterns. Weather detachment personnel were not assigned combat flying duties but did regularly participate in weather forecast flights out of England over the Atlantic to gather metrological data for the daily weather forecasts. In addition, weather detachment personnel flew as observers on combat missions to aid them in understanding weather effects on aircrew and operations. The detachment was assigned to bomb group headquarters under a senior staff officer. There were nine total personnel assigned to the weather detachment including two commissioned officers and seven enlisted men.
The weather detachment operated 24 hours per day with half the assigned personnel on each shift. While observers and forecasters performed separate jobs, in practice each would overlap the other's responsibilities for collecting and collating the voluminous data. Each detachment operated a complete weather station at each base. While the station detachment would issue a forecast for each day and specific forecasts for missions, the detachment also used the data provided by the staff weather officers from wing, division, and Eighth Air Force. Observers gathered data from multiple station instruments each day at specified times. The weather forecasters were commissioned officers who maintained and updated the weather maps for group headquarters.