FM 34-81: Weather Support for Army Operations
AIR WEATHER SERVICE SUPPORT TO ARMY UNITS
AWS is a numbered Air Force command within MAC. It exists to fulfill special worldwide environmental needs of the Air Force, Army, and other Department of Defense (DOD) agencies as directed by the Chief of Staff of the Air Force. AWS personnel and meteorological observing equipment are dedicated to support the unique requirements of the Army while it is in garrison or in a tactical environment. Such AWS units are trained and oriented by the Army on applicable Army organizations, concepts of operations, and weather sensitivities. This chapter describes how AWS is structured and how it supports the Army in the tactical environment.
AWS provides weather support using a centralized weather support structure encompassing large computer processing capabilities and personal tailoring of data for specific users. Air Force Global Weather Central (AFGWC) is at the hub of this structure. Its products are disseminated to theater weather centers which add weather products tailored to the needs of the theater.
WETMs supporting tactical Army units further tailor the products they receive to the near term, smaller AI needs of their supported Army command. The role of centralized products is to provide predominant features of displayed analyses for a given area and time which must be essentially the same for all WETMs. There are advantages to centralizing support for tactical operations. Centralizing support--
- Limits the size of the weather communications facilities.
- Concentrates highly skilled forecasting capabilities.
- Makes the use of large computers feasible.
- Assists and guides the forecasters.
- Saves time and makes products more timely.
- Makes processed information available.
- Significantly enhances the accuracy of forecasts.
Being communications-dependent is one serious disadvantage. When critical communications are disrupted or denied, WETMs must have a backup, stand-alone capability to produce weather products required to support Army units. Another disadvantage of automated weather products is that they are normally developed using a global data base, and mesoscale effects may be lost during the process. Figure 3-1 is an example of a weather information flow.
AIR FORCE GLOBAL WEATHER CENTRAL (AFGWC)
AFGWC at Offutt Air Force Base (AFB), Nebraska, is the largest meteorological center in the world and is the focal point for worldwide weather analysis and forecasting. Weather observations from all over the world are received there via high-speed communications networks along with other data such as satellite imagery.
This timely weather data base is processed on large, modern computers and by specialized weather technicians to analyze the earth's atmosphere in three dimensions twice each day. Sophisticated computer programs manipulate the complex interactions of data elements to develop forecast weather products for immediate dissemination to weather personnel worldwide. These products consist of standard analysis and prognosis charts as well as specialized products requested by SWOs at all support levels.
UNITED STATES AIR FORCE ENVIRONMENTAL TECHNICAL APPLICATIONS CENTER (USAFETAC)
USAFETAC is a part of the AFGWC although geographically separated. USAFETAC stores and processes worldwide climatological data. This data is vital for long-range planning, IPB, and near-term contingency requirements.
FORECAST UNITS (FUs)
Complementing AFGWC are permanent weather centers in other parts of the world which, in addition to AFGWC products, provide tailored products for their respective theaters. These FUs are dedicated to providing weather support to joint US forces or Combined Forces operating in wartime. Currently, FUs are located in Europe, Alaska, Korea, and Central America.
The tactical arm of the AWS support structure is aligned with the vertical command structure of the supported forces. The structure of supported forces often varies depending on the level of conflict, theater of operations, and duration of the conflict. To accommodate these differences, the weather support force adapts to the supported force structure by assigning tactical WETMs to key elements of the command structure during peacetime. These teams deploy with their supported units during a war or contingency.
TACTICAL FORECAST UNITS (TFU)
A TFU would be established at the joint task force (JTF) level to provide support for a specific geographical area or combat operation. It would be activated and deployed to support a wartime mission or contingency. It is either redeployed or deactivated upon completion of the mission. The TFU supports lower echelon WETMs through--
- Direct relay of products from AFGWC, USAFETAC, and the theater FU.
- Limited editing and tailoring of products.
- Local generation of new products.
The TFU may provide all centralized products, using various data sources, during periods when other AWS system support is not available.
USAF TACTICAL WETM
The WETM prepares operational forecasts and user interface. It is the WETM forecaster or SWO who tells the user what the weather is going to be. The WETM tailors and refines the forecast guidance received from FUs to the specific operational needs of the user in terms of time, space, and form of presentation. Remote support is provided to subordinate commands of each echelon through the G2 or S2 section, which is responsible for transmitting forecasts and weather information to those users in the field. Call-up capability from the subordinate commands to the WETM for special requests or unscheduled forecasts is through area communication networks. Army support WETMs--
- Make maximum use of weather observations from Army sources.
- Use support from other US and Allied weather services.
- Use weather data from all sources both friendly and enemy.
- Use information from weather radar and satellites when available.
- Request specialized forecast products from centralized forecast facilities.
The following describes various weather support teams, their functions, and responsibilities.
--SOF includes SFGs and ranger regiment.
--Corps aviation brigade.
--Division landing zone (LZ).
--Division aviation brigade.
--Mobile observing teams.
When weather support force structure changes are required, the SWO requiring the change will coordinate the change with the supported command and request approval from the SWO at the next higher echelon. For example, if an ACR or separate brigade were to be under operational control to a division, to fight as a division brigade, the division SWO may request that the observer, forecaster, or SWO function be removed from the ACR or brigade WETM and be reallocated. This would be coordinated with the division commander, and the corps SWO would approve or disapprove the decision after consulting with the corps staff.
WETMs will be composed of one or a combination of--
- Officer and noncommissioned officer (NCO) forecasters.
- Weather observers.
- Administrative specialists (at division and higher echelons).
Each element of a WETM has specific responsibilities stated below. They are provided as guidelines for WETM members to provide insight on the WETM's mission, capabilities, and functions. Some responsibilities may not apply or must be tailored to the supported mission, and in some cases, team members share responsibilities. For example, it is common for the SWO to delegate many SWO responsibilities to the NCO forecasters and for NCO forecasters to take, record, and transmit weather observations.
Staff Weather Officer. The SWO, the senior officer of an echelon WETM, is a member of the Army commander's special staff, under the commander's operational control and under the general staff supervision of the G2 or S2. The SWO coordinates directly with the commander and staff on weather service matters and on weather and climate. While tactically deployed, WETM members are under the command of the WETM SWO. Each SWO falls under the command of the SWO to the next higher echelon of command in the weather support force structure; this normally parallels the supported Army force structure. The senior theater SWO has command authority of all weather support force theater personnel. The SWO--
- Commands the WETM and coordinates Air Force weather support activities.
- Advises the supported Army commander on weather support matters to include advice on the use of weather support to enhance the efficiency of combat operations.
- Coordinates with the G2 where subordinate SWO, forecasting, and observing WETM elements are employed.
- Provides daily weather briefings to commanders and their staffs to support current and future operations.
- Provides weather effects information with particular attention to critical weather threshold values which limit systems, operations, or tactics.
- Coordinates with staff officers in determining optimum systems, operations, and tactics to meet mission objectives.
- Prepares weather annexes to plans of the supported command, reviews weather annexes of subordinate commands, and ensures the stated responsibilities are met.
- Advises the Army commander of Air Force weather support capabilities and limitations; coordinates effective methods of providing support to plan and carry out Army operations.
- Requests and/or prepares climatological studies and analyses in support of planned exercises, operations, and commitments.
- Develops weather support procedures and trains Army personnel to use and understand weather information.
- Assists in arranging remote weather support for subordinate units of the command.
- Advises the Air Force of new or unfilled operational weather support requirements for the supported Army command.
- Assists in determining weather support data requirements.
- Monitors weather support provided to lower echelons of the supported Army command.
- Advises the G2 on the need for Army provided weather observations from forward areas.
- Coordinates communication requirements for weather support.
- Monitors meteorological conditions in the AI.
- Evaluates weather data received from the Army or collected by the Air Force.
- Provides weather products for IPB.
- Works closely with engineers, fire support officers (FSOs), G3's, air defense artillery, signal, and other special staff officers.
- Works closely with the chemical officer in discussing the overall synoptic situation; ensuring low-level inversions, wind shifts, diurnal changes, and microscale terrain effects on weather are discussed in detail.
- Coordinates with field artillery to receive upper-air and surface observations taken by the ARTYMET section.
- Provides the ARTYMET section with data when needed.
- Ensures operator maintenance of Army supplied equipment.
Weather Forecaster. The weather forecaster, either an officer or an NCO, is the specialist who applies the weather analysis and forecasting tools to the weather data base. Weather analysis, the intervening step between weather observing and forecasting, is based on observations over a synoptic area. Synoptic observations require that all observations be taken on a predetermined schedule. These observations include surface and upper air, taken from all sites, inside and outside the operational area.
The unscheduled observation data acquired by many Army units in support of their own operations are also important to the forecaster. Weather forecasting capabilities are the greatest at the higher echelons where specialized personnel and computerized equipment can be used. At lower echelons, weather forecasters tailor forecasting products to the particular requirements of supported Army units. Weather forecasters--
- Monitor and analyze weather observations, forecasts, satellite imagery, radar information, and other data received.
- Ensure data critical for accurate analysis is requested.
- Keep the SWO informed of current and expected weather, particularly conditions adverse to the supported mission.
- Tailor forecast information received from higher echelons to the supported mission.
- Provide services normally provided by higher echelon WETMs if these units are not available.
- Collect and forward to higher echelons the forecasts and observations from lower echelons.
- Assist the SWO and perform delegated SWO responsibilities.
- Perform the meteorological watch for specific routes, target locations, and AIs.
- Disseminate products to the G2 or S2.
- Coordinate forecasts with other WETMs.
- Operate all meteorological equipment including satellite receivers, radar, or other available weather data display equipment used as the basis for weather forecasting.
- Prepare and disseminate forecasts. Forecast services include providing--
--Forecasts focused on specific missions, locations, and weather parameters critical to current operations and for future planning.
--Forecasts of upper-air winds.
--Forecasts of precipitation and temperature amounts to support terrain team hydrographic and trafficability predictions.
--Forecasts and mission briefings to aircrews which may be operating from the division LZ.
--Data for chemical downwind messages.
--Nuclear fallout bulletins from the theater-level WETMs.
--Tailored forecasts for transmission to lower echelons.
--Forecasts and observations, as required, to ATC.
--Astronomic, climatic, oceanographic, and illumination data.
--Weather products for IPB.
--Weather warnings for mission areas and deployed locations.
--Forecasts tailored for other MSCs. For example, road condition forecasts for logistic support; precipitation forecasts for maintenance facilities; the most usable radio frequencies for signal elements; and the height of inversion, stability, and low-level wind forecasts for deliberate smoke operations.
Weather Observer. Enlisted weather observers provide part of the basic observation input for weather support to the tactical Army. The continuous monitoring of atmospheric conditions, recording of surface weather observations, and transmitting data to higher echelons provide the basis for forecasts and are essential to satisfy Army requirements for current weather information. Weather observers--
- Take, record, and disseminate weather observations.
- Assist the forecaster in weather station operations.
- Plot standard weather maps and charts.
- Receive and forward FALOPs and aircraft observations pilot reports (PIREPs) or target weather indicators (TARWIs) from lower to higher echelons.
- Update or transmit weather displays to the TOC.
- Operate all meteorological equipment including satellite receivers, radars, weather data display, and applicable data transmission and receiving equipment.
- Assemble and operate modification table of organization and equipment (MTOE) and tables of distribution and allowance (TDA) items.
- Train Army personnel to take limited observations.
- Relay observations and forecasts to aircrews, ATC personnel, and other agencies on request.
Administrative Specialist. Administrative specialists are an integral part of the WETMs they are assigned to support. While they are not weather specialists, their assistance in managing administrative details is essential to the WETM's success.
WETMs assigned to different echelon levels are tailored to meet the customer's mission and requirements described in Chapter 1. The following provides details of the WETM structure and the support provided to each level of command.
EAC. EAC is supported by an EAC WETM that generally is derived from the headquarters of the weather squadron that supports the MACOM during peacetime. The commander of that weather squadron is the MACOM SWO and, when deployed, becomes the EAC SWO. The WETM may split into cells to support--
- EAC main, rear, and alternate CPs.
- EACIC operations.
Weather support requests beyond those cells that are unique to a theater of war will be identified by the MACOM to the appropriate Department of the Army (DA) and Air Force staff element. Figure 3-2 shows the locations of the EAC WETM cells and support provided, but depend highly on the theater of operations, contingency, or command structure supported.
In general terms, the EAC WETM functions as the center for weather support to a multicorps operation. Using centralized products from the AWS system, the WETM prepares and tailors products to meet the needs of the EAC commander staff, and subordinate commanders. In addition, finished weather products are prepared to support independent operations. These operations include those of corps, divisions, separate brigades, SOF, aviation brigades, and ACRs whenever the products are not immediately available from the AWS system.
The EAC WETMs--
- Provide weather support to the EAC commander by monitoring meteorological conditions in the lines of communication (LOC), aerial ports of debarkation (APODs), and seaports of debarkation (SPODs).
- Monitor all WETMs that are providing weather support to Army units in the theater.
- Provide a briefing or forecast cell at EAC headquarters. This may be a combined meteorological cell (CMC) with Allied weather services in some theaters.
- Receive, edit, and reformat AFGWC and FU or TFU products into tailored packages for routine distribution to WETMs at corps and below.
- Disseminate all products at EAC to corps and below WETMs.
- Incorporate indigenous products with AFGWC products when developing the weather support plans and annexes.
- Ensure lower echelon WETMs write weather support plans and annexes at their levels and provide general guidance and monitoring of the Army weather support procedures across the theater.
The EACIC WETM--
- Provides climatic and meteorological services in support of the EACIC's intelligence and electronic warfare (IEW) functions.
- Prepares weather analysis products for weather analysis functions of IPB.
- Prepares tailored weather forecasts for the EACIC's target development electronic warfare (EW), counter intelligence, and indications and warning functions.
In addition, weather forecasts are used to help determine which of the MI brigade's collection assets should be employed. Other tailored forecasts and weather observations are provided to support the theater intelligence imagery gathering systems. The EACIC SWO is under the command of the EAC SWO and functions as the weather advisor within the EACIC.
The EAC WETM will provide two 24-hour observing cells to support air traffic at two EAC airfields. For joint and/or combined operations in a theater where a corps does not exist, the theater aviation group or brigade is also a theater aviation unit equal to that of the corps aviation brigade. These requirements include direct, tactical SWO, and 24-hour forecasting and observing support.
Special Operations Forces. Army special operations forces (ARSOF), which include SFGs and ranger regiments, are likely to be employed on politically sensitive, high-risk missions. Employment methods are often highly sensitive to environmental conditions since sophisticated weapons and delivery systems require specific environmental conditions for successful operation.
ARSOF missions include--
- Deep reconnaissance.
- Direct action.
- Terrorism counteraction.
- Unconventional warfare.
- Foreign internal defense.
- Psychological operations (PSYOP).
- Civil affairs.
These ARSOF missions are often joint and/or combined and conducted worldwide, through all types of conflict. A special operations weather team (SOWT) supports the SFG or ranger regiment.
Special Forces Groups. When deployed, the C2 element of the group headquarters is located at the special forces operational base (SFOB). The SFOB receives direct SWO and 24-hour forecasting and limited observing support. Each SFOB can control up to three battalions located at FOBs. FOBs are normally composed of C2 elements from the special forces battalion. Each battalion receives 24-hour forecasting and limited observing support because of the great distances between the SFOBs and FOBs. These isolated locations require special communications or satellite links to relay required basic weather data for forecasts and IPB planning. Figure 3-3 shows the USAF support to SFGs.
Figure 3-3. (21)
Ranger Regiments. Direct weather support is provided by a WETM to support ranger regiments. Figure 3-4 shows SWO, 24-hour forecasting, and limited observing support provided to the ranger regiments.
Figure 3-4. (12)
Corps. The corps WETM--
- Provides dedicated, 24-hour weather support to the corps headquarters.
- Operates in the corps TOC area and is supported by the corps headquarters and headquarters company (HHC).
- Functions as the Army Forces (ARFOR) TFU when no higher echelon is employed.
- Provides guidance to subordinate WETMs at the divisions, separate brigades, and ACRs. This guidance includes tailored weather products of sufficient detail to support their different operations.
- Functions as a hub for collecting weather observations, ARTYMET upper-air soundings, and FALOP data from lower echelons.
- Passes observations from adjacent divisions and corps to its division WETMs so they have a complete picture of the battlefield.
- Operates and maintains weather-dedicated Army equipment including vehicles, generators, and communications equipment (except high frequency (HF) radio teletypewriter (RATT) equipment).
- Maintains other common table of allowances (CTA) equipment such as tents and heaters.
- Functions 24 hours a day and is capable of observing weather and providing forecasting support to a tactical CP for limited periods.
This information is incorporated into the AFGWC data base to make the next forecast and is passed to the theater FU, TFU, or EAC WETMs for their immediate interests. The theater FU, TFU, or EAC WETM ensures that the Air Force forces (AFFOR) WETM gets the lower echelon observations and forecasts so planners for both Army units and tactical air (TACAIR) sorties have coordinated forecasts.
Twenty-four hour observing support is provided for two corps airfields. The location of each WETM is determined by the SWO in coordination with the corps G2.
Corps aviation brigade. The corps aviation brigade receives direct weather support from its separate WETM. This WETM relies on the corps aviation brigade HHC for its field equipment and support. The WETM provides SWO and 24-hour forecasting and observing services to the corps aviation brigade commander and staff. The observing team provides observations from a field aircraft landing zone (LZ). The aviation brigade SWO will coordinate with the aviation brigade S2 to ensure communication and support to the weather observers. The purpose of the WETM is to--
- Help preserve the integrity of the brigade by minimizing aircraft damage and dispersal caused by adverse weather and environmental effects.
- Provide the commander with forecasts on the best opportunity to use aviation to exploit enemy vulnerabilities.
- Maximize the advantage of sophisticated weapon systems, then rapidly determine effects of weather, and turn inside the enemy's decision cycle.
- Plan deep operations in favorable weather conditions.
- Sequence aviation brigade attacks to support the corps commander's plan.
Tailored forecasts and observations help determine--
- Target acquisition ranges.
- Night operations limitations.
- Cargo lift capabilities.
- Flight paths.
- Nuclear, biological, chemical (NBC) prediction. The aviation brigade WETM is capable of providing limited weather support to the corps main CP if needed.
Corps weather support is organized to provide direct support to corps operations as shown in Figure 3-5.
Armored cavalry regiment. An ACR is designed to function as a separate entity under a corps, thus it has its own separate WETM for direct weather support. The ACR WETM acquires its field equipment and support from the ACR headquarters and headquarters troop (HHT). Its highly mobile battle plan, with heavy use of weather sensitive aviation assets, requires the unique tailoring of the WETM.
The current WETM structure is designed for the early stages of battle and may require restructuring as the ACR mission evolves. SWO support is provided at the ACR CP to support the current battle planning strategy and command of the forces. Direct SWO and 24-hour forecasting and observing support are provided at the aviation squadron; 24-hour observing is dedicated for the ACR (LZ) to support organic aviation squadron air traffic. Figure 3-6 shows USAF weather support to ACRs.
Separate brigades. Direct weather support is provided by a WETM to support separate brigades since these units are designed to function as separate entities under the corps. Field equipment and support to this brigade WETM are provided by the HHC. SWO and 24-hour forecasting and observing are provided at the separate brigade CP as shown in Figure 3-7.
The differences in capabilities, mission, and tactics of these units require that weather support be tailored to each unit just as it is for divisions. Weather support in the separate brigade closely parallels weather support in the division.
The difference between the support is that in the separate brigade heavy emphasis is placed on the close-in operations. Close-in operations narrow the scope of the AO and focus of weather support. Normally, current observations and 12-hour forecasts are provided for close-in operations.
The WETMs place emphasis on current observations from Army field elements to support the commander's immediate battle plan and as the basis for forecasting support. Adverse weather limits surveillance and air operations. Precipitation may limit maneuver since these units depend on speed and maneuverability for survival. The AI of these units also depends heavily on how they are employed and their capability. As a corps asset, this could coincide with the distance and time requirements of the corps for planning deep operations.
Division. The division WETM operates in the division main CP area and receives support from the division HHC. The division SWO is the commander of the WETM attached to the division The WETM--
- Provides direct SWO and 24-hour forecasting and observing support to division commanders and their staffs at the division main CP.
- Provides 24-hour direct support at the tactical CP for limited periods.
An observing team supports the division LZ. Remote forecasting support is provided from the division CP.
Mobile observing teams. Three mobile observing WETMs are organic to the division WETM. They will be deployed within the division area at the direction of the SWO after coordination with the G2. These teams provide--
- Special weather observations from locations which are critical to operations, such as along air corridors.
- Information for joint weather sensitive missions.
- Support forecasts for specific areas.
Division aviation brigade. Support to the division aviation brigade is provided by a separate WETM. This WETM receives its support and field equipment from the aviation brigade HHC. Mission and support requirements for the division aviation brigade are similar to those of the aviation brigade discussed previously. Figure 3-8 shows USAF weather support to a division.
Division types. Division support will vary with the type of division. Each type of division must be capable of continuous operations. Thus some support, such as illumination requirements for night vision devices, is important to all divisions.
Heavy divisions are concerned with cross-country movement of armored vehicles and rely on accurate and timely precipitation data and forecasts to plan tactical movements. Heavy divisions are equipped with a wide range of E-O guided weapons. The effectiveness of their weapon systems may be degraded by precipitation, fog, or snow-covered targets.
Air assault divisions rely on rotary-wing aircraft for their mobility. Consequently, direct forecasting and observing support is provided at each maneuver brigade TOC. Of prime importance are forecasts and observations of low-level cloudiness, gusty surface winds causing turbulence in LZs, aircraft icing conditions, and reduced visibility caused by fog or precipitation. A forecaster's attention is more focused on aircraft briefings in an air assault division than in any other division. Temperature, humidity, and LZ elevation are key factors in determining aircraft lift capability, especially in areas with large daily variations in temperature.
The light infantry division fights best in reduced visibility and darkness. It is concerned with the individual soldier and the performance of the weapons in adverse weather conditions. Heat and glare from the sun, cold and windchill, precipitation, and the trafficability conditions are of increased importance to the light forces that move on foot. Restrictions to visibility from dust or falling precipitation that affect the performance of night vision goggles and night sights are very important.
Some divisions have areas of specialization because of their assigned missions; for example, cold weather operations, desert operations, or jungle warfare. For these environments the SWO will provide special climatic studies and evaluations as required. Division operations manuals in all of these areas explain the concept of operations to which the SWO and the WETM tailor their forecasts.
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