The weather at Khe Sanh throughout February could be characterized in one word--miserable. General Tompkins remarked that, for combat purposes, the weather was the worst that he'd ever seen. The northeast monsoons had long since spilled over into the Khe Sanh Valley and every morning the base was shrouded with ground fog and low scud layers which dissipated around 1000 or 1100. When the sun finally managed to burn through, the cloud ceiling retreated slightly but still hovered low enough to prevent the unrestricted use of airborne artillery spotters and strike aircraft. It was during these periods, when the overcast was between 100 and 500 feet, that enemy artillery, rocket, and mortar fire was the heaviest. The NVA forward observers, perched along the lower slopes of the surrounding hills, called in and adjusted barrages with little fear of retaliation against their own gun positions. Later in the afternoon, when the fog rolled in again and obscured the enemy's view, the incoming tapered off.[33](114) The Marines adjusted their schedule accordingly. They usually worked under the cover of the haze in the morning, went underground during the midday shelling, and returned to their duties later in the afternoon. While the extremely low cloud cover occasionally befriended the men at the base, it constantly plagued the pilots whose mission was to resupply the 26th Marines. The job of transporting enough "bullets, beans, and bandages" to sustain the 6,680 Khe Sanh defenders fell to the C-130s of Marine Aerial Refueler Transport Squadron 152 and the U. S. Air Force 834th Air Division; the C-123s of the 315th Air Commando Wing; the UH-34, CH-46, and UH-1E helicopters of Marine Aircraft Group 36 (MAG-36); and the CH-53 choppers of MAG-16.[34](115) [Illustration: Ground fog in the morning and late afternoon shrouded the base obscuring the view of both the enemy and the Marines. (Photo courtesy David D. Duncan)] [Illustration: The reduced visibility from fog and haze hampered air operations. Crews of Marine UH-1E gunships wait for ceiling to lift. (Photo courtesy David D. Duncan)]