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Fm 1-30 Meteorology for Army Aviators

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Fm 1-30 Meteorology for Army Aviators plh i-Ä3i> FM 1-30 METEOROLOGY FOR ARMY AVIATORS 3ft \ 'ih \ w &T "V Æ -TTr A C4 UPf. f'-'A \ is '■Q&3Î, & ^ î W? vA HEADQUARTERS, DEPARTMENT OF THE'ARMY MAY 1976 RETURN TO ÄSi'Y LIBRARY ROOM 1 A 516 PENTAGON c. l 11 I I L \ ii j *FM 1-30 FIELD MANUAL HEADQUARTERS DEPARTMENT OF THE ARMY No. 1-30 WASHINGTON, D.C., 31 May 1976 METEOROLOGY FOR ARMY AVIATORS Paragraph Page PART ONE. WEATHER PRINCIPLES AND THEORY CHAPTER 1. INTRODUCTION 1- 1-1 1—1-5 2. THE ATMOSPHERE I Section I. General 2- 2-1 1—2-3 II. Temperature and Heat Energy 2-4—2-10 2-3—2-8 III. Moisture 2-11—2-15 2-10—2-15 IV. Pressure 2- 2- 116—2-23 5—2-22 CHAPTER 3. CLOUDS Section I. General 3- 3- 11, 3-2 II. Cloud Types 3- 3- 32—3-6 , 3-3 CHAPTER 4. ATMOSPHERIC CIRCULATION Section I. General Circulation 4- 4- 11—4-6 —4-4 II. Secondary Circulation 4-7—4-10 4-9—4-14 III. Hurricanes 4- 4- 111—4-20 9—4-23 CHAPTER 5. ATMOSPHERIC STABILITY AND INSTABILITY Section I. Atmospheric Stability 5- 5- 11—5-6 —5-6 II. Interpreting the Atmospheric Sounding Diagram 5- 5- 77—5-9 , 5-8 CHAPTER 6. AIR MASSES Section I. General 6- 6- 11—6-6 , 6-2 II. Air Masses Affecting the United States 6- 6- 73—6-11 —6-7 CHAPTER 7. FRONTAL WEATHER 7- 7- 11—7-7 —7-17 8. FOG 8- 8- 11—8-5 —8-3 9. ICING 9- 9- 1l—9-15 _9-ll 10. THUNDERSTORMS 10- 10- 13—10-8 —10-17 PART TWO. WEATHER FACILITIES AND THEIR APPLICATION CHAPTER 11. WEATHER SYSTEMS Section I. General 11- ll_l_H-8 1—11-5 II. Teletype Sequence Reports 11-6—11-20 11-10—11-22 CHAPTER 12. SURFACE FACSIMILE MAPS 12- 12-1—12-8 1—12-5 13. WINDS ALOFT 13- 13- 11—13-5 14. CONSTANT PRESSURE CHARTS AND HIGH ALTITUDE WEATHER 14- 14- 11—14-10 —14-8 15. RADAR AND WEATHER 15- 15- 11—15-7 —15-7 CHAPTER 16. FORECASTS Section I. Introduction 16- 16- 11,16-2 II. Teletype Forecasts 16-3—16-5 16-1—16-7 III. Facsimile Prognostic Charts 16-6—16-9 16-8—16-10 CHAPTER 17. WEATHER FLIGHT PLANNING Section I. Preflight Planning 17-1_17-5 17-1—17-3 II. In-flight Planning 17-6—17-8 17-6—17-8 APPENDIX A. REFERENCES A-l B. UNITS OF MEASURE FOR METEOROLOGICAL ELEMENTS B-l C. WEATHER OUTSIDE THE TEMPERATE ZONE C-l Section I. Polar and Subpolar Regions. c-l—C-4 II. Tropical Weather C-5—C-7 GLOSSARY . Glossary-1 INDEX Index-1 m *This manual supersedes TM 1 —300, r10 June 1963, including all changes. ■ I *4 PART ONE WEATHER PRINCIPLES AND THEORY CHAPTER 1 INTRODUCTION 1 — 1. Purpose must also avoid severe turbulence and plan his This manual provides Army aviation personnel with flight to cope with icing conditions that could exist the general principles of modern meteorology. Its in cloudless air. primary purpose is to serve as a text for the Army 1 —4. Meteorology in the High Threat aviator’s study of meteorology and as a continuing reference for day-to-day flight operations. However, Environment it also has application and provides meteorological The effects of weather on the battlefield and adjacent information that can assist in planning and conduct- areas can, in many cases, determine the decisions of ing combat operations. the commander and significantly influence the out- come of the battle. Army aviation units, as an essen- 1 -2. Scope tial part of the combined arms team, must be able to a. This manual covers theoretical aspects of mete- operate successfully in a number of differing meteor- orological phenomena, the weather facilities available ological environments and landscapes affected differ- at airfields, severe weather warnings, types of fore- ently by the weather. The high threat posed by the cast, and information which will enable Army avia- enemy on the battlefield makes it necessary to con- tion personnel to interpret and evaluate weather duct combat operational missions in the terrain conditions. Although the general information con- flight environment close to the earth’s surface to tained in this manual is required background infor- avoid detection by electronic means and destruction mation for weather forecasters, the manual does not by highly sophisticated air defense weapons. It is include operational forecasting techniques. essential that Army aviation units be able to provide b. Users of this manual are encouraged to submit firepower, movement of troops, logistical support, recommended changes or comments to improve the and surveillance and reconnaissance for the ground manual. Comments should be keyed to the specific tactical elements even during periods of adverse page, paragraph, and line of the text in which the meteorological conditions. Army aircraft will operate change is recommended. To insure understanding routinely with a minimum of navigational aids and and complete evaluation, reasons should be provided minimum air traffic control facilities. Each aviator for each comment. Comments should be prepared must be dependent on individual proficiency and using DA Form 2028 (Recommended Changes to knowledge of meteorological phenomenon to make Publications and Blank Forms) and forwarded to the critical decisions concerning the mission, his crew Commander, US Army Aviation Center, ATTN: and passengers, and flight paths. New equipment ATZQ-TD-TL, Fort Rucker, AL 36362, enabling flight under instrument conditions with c. A list of pertinent references is contained in minimal navigational aids must be complemented appendix A. with a thorough understanding of meteorological conditions and the ability to interpret and use it 1 —3. General effectively. Army aviators must be knowledgeable Army aviators must be knowledgeable of existing of meteorological conditions and factors to be able weather conditions prior to commencing a flight. to make the critical decisions necessary and to To do this, the aviator must have a thorough knowl- operate successfully in the high threat environment. edge of the meteorological conditions and factors which produce the weather along his flight route. 1—5. Military Weather Support Functions Although modern navigational systems and flight a. Military meteorological services are specialized techniques make flight into instrument meteor- services organized worldwide to satisfy unique ological conditions (IMC) possible, flight into haz- military requirements. Mobility, responsiveness to ardous weather conditions must be avoided. Not only combat readiness requirements, and alertness to must the aviator be knowledgeable to discern and complement the new weapons systems and concepts avoid hazardous weather associated with IMC, he are hallmarks of the military weather support 1-1 FM 1-30 services. General military user requirements include, Army by the Air Force Air Weather Service. Army but are not limited to: meteorological information meteorological sections provide data, which is assim- necessary to support or enhance particular weapons ilated with other environmental data, in order for systems being deployed or employed; unique fore- the Air Force to make accurate weather forecasts. casts and analysis for command and control systems; (2) Specific meteorological support provided by specialized information such as ballistic data, impact Army weather units include such operations as: prediction, meteorological advisory, and test analysis (a) Meteorological observations and soundings assistance to research and development; and general in the support of artillery weapons systems. meteorological support and information for training (b) Meteorological observations forward of and deployment of military forces. These services division headquarters elements except at some are provided by forecasting and observation facilities, designated airfields. aerial reconnaissance, meteorological satellites, (c) Specialized meteorological support to Army air-transportable units capable of deploying meteor- research and development activities. ological support equipment and personnel to support (d) River-stage and flood forecasting. tactical operations, and a global communications (3) To support artillery weapons systems, there network. is one meteorological section located in each division, b. Atmospheric processes have a significant and two additional sections at each corps level. impact on Army operations. For this reason, the These sections are capable of generating the following Army is continually developing and improving five types of meteorological messages: techniques and equipment that will provide near • NATO ballistic meteorological message. real-time meteorological information as related • Computer ballistic meteorological message. to weapons systems. Since Army operations are • Fallout meteorological message. principally affected by local weather phenomena • Sound-ranging meteorological message. because of the relatively small area over which • Meteorological message for the Air Weather they are concentrated, Army meteorologists are Service. concerned primarily with the detailed weather (4) The ballistic messages allow artillerymen to information in the lower atmosphere directly over make corrections for wind, temperature, and atmos- the battlefield area. pheric density—any of which can cause a projectile (1) Operational environmentto miss servicesits intended for weather target. The fallout message conditions over the immediate battlefield area are allows the corps chemical officer to plot the areas provided by a combination of both the Army and the of nuclear fallout, while the sound-ranging message Air Force environmental service units. However, allows enemy weapons to be located by the sound operational weather forecasting is provided to the of their firing. CHAPTER 2 THE ATMOSPHERE Section I. GENERAL 2 — 1. General a. The atmosphere is the great envelope of air which surrounds the earth. Approximately one-half of the air, by weight, is within the lower 18,000 feet of the atmosphere; the remainder is spread out over a vertical distance in excess of 1,000 miles. No definite outer atmospheric boundary exists; the 21% air particles become less numerous with increasing OXYGEN altitude until they gradually overcome the earth’s gravitational force and escape into space.
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