Weather Effects During The Battle Of The Bulge And The Normandy Invasion ABSTRACT "A general description of the terrain of the Ardennes-Ejiel area is given, and weather related decisions concerning the final attack date and the buildup of the German offensive push are noted. Surface meteorological charts for 16 and 23 December 1944 are presented and show that a modified cold maritime polar air mass was over the Ardennes-Ejiel area when the Battle of the Bulge began. Weather related instances on the battlefield are noted, particularly where fog or snow reduced visibility and where thaws or freezes influenced trafficability. Weather events leading up to D-day are given, and surface weather charts for 3, 4, and 6 June 1944 are shown. Adverse weather conditions before D-day and the lack of timely surface observations caused the German commanders not to suspect an invasion on 6 June 1944. The Germans had no knowledge that a maritime polar air mass was pushing into France from the northwest and would cause weather conditions suitable for the invasion. ACKNOWLEDGMENT I wish to acknowledge the helpful discussions with Mr. Jack Allen and Mr. James Devine in the preparation of this report. The actual weather conditions for tactical Air Force bases and northern battle areas were provided by Mr. John Fuller, Air Weather Service historian." CONTENTS LIST OF TABLES 6 LIST OF FIGURES 6 INTRODUCTION 7 BATTLE OF THE BULGE Terrain, Roads, and Climate Decisions and Weather 9 Decisions 9 Weather and Related Engagements: 16-22 December 1944 10 23-27 December 1944 13 THE NORMANDY INVASION 14 Weather and the Great Decision 14 The Invasion and Supplies 16 SUMMARY 18 TABLES 19 FIGURES 22 REFERENCES 33 LIST OF TABLES 1. Actual Weather Conditions for Tactical Air Force Bases and Northern Battle Areas 19 LIST OF FIGURES 1. The Western Front on 15 December 1944 22 2. Surface meteorological chart for 15 December 1944 23 3. Meteorological conditions, 16-22 December 1944 24 4. Locations of small villages in Belgium and Western Germany 25 5. Locations of small villages in Belgium and Luxembourg 26 6. Surface meteorological chart for 23 December 1944 27 7. Meteorological conditions, 23-27 December 1944 28 8. Weather chart for 1300 Gmt, 3 June 1944 29 9. Weather chart for 1300 Gmt, 4 June 1944 30 10. The Normandy Beachhead 31 11. Weather chart for 0700 Gmt, 6 June 1944 32 Digitized by www.dtic.mil NTIS Accession no. AD-A121 480/8., Includes bibliographical references, Photocopy, Introduction -- Battle of the Bulge : Terrain, roads, and climate ; Decisions and weather -- The Normandy invasion : Weather and the great decision ; The invasion and supplies -- Summary, A general description of the terrain of the Ardennes-Eifel area is given, and weather-related decisions concerning the final attack date and the buildup of the German offensive push are noted. Surface meteorological charts for 16 and 23 December 1944 are presented and show that a modified cold maritime polar air mass was over the Ardennes-Eiffel area when the Battle of the Bulge began. Weather-related instances on the battlefield are noted, particularly where fog or snow reduced visibility and where thaws or freezes influenced traffficability. Weather events leading up to D-day are given, and surface weather charts for 3, 4, and 6 June 1944 are shown. Adverse weather conditions before D-day and the lack of timely surface observations caused the German commanders not to suspect an invasion on 6 June 1944. The Germans had no knowledge that a maritime polar air mass was pushing into France from the northwest and would cause weather conditions suitable for the invasion