The early morning sun glared through the windows of the flight school’s worn Cessna as pilot Maria Hernandez finished up her preflight planning.

She felt confident about today’s short cross-country flight from Dallas to Waco that would complete her instrument rating. The familiar automated voice on the ATIS frequency at Dallas Executive Airport reported clear skies with unlimited visibility – perfect flying conditions.

With a final check of the weather radar showing clear skies ahead, Maria started up the engine and taxied to the runway, ready for an easy 1-hour hop.

But 20 minutes into the flight, Maria noticed a thick wall of dark clouds rapidly approaching from the west. She contacted the AWOS station at Waco Regional Airport and got alarming news – a fast-moving cold front had arrived, bringing heavy rain, low ceilings, and poor visibility.

Caught off guard by the stark difference in weather reports, Maria had no choice but to turn around. As she later recounted, “It was like having your altimeter suddenly read 1,000 feet lower right before landing. I learned the hard way just how much ASOS, AWOS and ATIS can vary.”

Like trusted cockpit instruments, automated weather reporting systems provide the vital data pilots need to navigate safely. But fully utilizing these tools requires understanding their unique capabilities and limitations.

This guide will help pilots better leverage ASOS, AWOS and ATIS to make every flight a smooth one.

Table of Contents

Key Points

ASOS offers continuous automated weather observations via multiple platforms like internet and radio.

AWOS provides basic to detailed weather data, especially for uncontrolled airports.

ATIS focuses on airfield conditions and advisories for arriving aircraft at major airports.

Checking multiple sources provides the most complete weather picture for sound flight planning.

Your Essential Weather Reporting Systems

Modern aviation relies extensively on automated weather systems like ASOS, AWOS and ATIS to supply regular and reliable data quickly. However, each serves a distinct purpose and reports unique information.

ASOS, the Automated Surface Observing System, is the most comprehensive and accessible system. Maintained jointly by the FAA, National Weather Service, and Department of Defense, ASOS provides continuous automated reports on weather elements like winds, visibility, cloud layers, temperature, dew point and precipitation type.

It supplies this data not just over radio frequencies but also via the internet and phone recordings. For many pilots, ASOS offers the first glimpse of weather conditions when planning a flight.

AWOS, the Automated Weather Observing System, fulfills a similar role but is focused on serving smaller uncontrolled airports and heliports that lack human weather observers. The FAA manages AWOS stations, which come in different configurations offering varying levels of detail.

While some provide only basic wind, temperature and altimeter readings, the most advanced AWOS-3PT includes cloud height, visibility, precipitation type and lightning strike detection. For remote airports not served by ASOS, AWOS delivers invaluable weather intelligence.

Rounding out the trio is ATIS, or Automated Terminal Information Service. ATIS transmits a continuous looped broadcast over a set radio frequency strictly focused on airfield conditions and advisories for arriving aircraft.

The familiar dulcet tones of ATIS paint a word picture of weather, runway use, and hazards specifically for the airport environment. This dedicated communication stream helps reduce frequency congestion while providing a constant weather beacon for inbound pilots.

Like having a backup altimeter and artificial horizon in the cockpit, leveraging these three systems together provides redundancy and a more complete weather profile.

The next section explores exactly what vital details each system can provide.

Crafting a Complete Weather Picture

To take full advantage of ASOS, AWOS and ATIS during flight planning, pilots must understand what weather data each system can and cannot provide. Like Maria discovered on her complicated cross-country flight, relying on just one source can leave you with only half the story.

ASOS serves as the most robust weather observation tool, reporting:

Visibility, cloud layers and ceilings
Temperature, dewpoint, winds aloft
Precipitation type and accumulation
METARs

AWOS capabilities vary based on the installed sensors:

AWOS-1 provides wind speed/direction, temperature and altimeter setting.
AWOS-2 adds visibility to that mix.
AWOS-3 includes cloud and ceiling details.
AWOS-3P identifies precipitation type and intensity.

ATIS focuses solely on the terminal environment:

Airfield advisories like runway closures
Wind, visibility, temperature, altimeter setting
Cloud cover and ceiling for airport vicinity

Unlike ASOS, ATIS does not report precipitation type or density. And AWOS-1 systems will lack the cloud layer visibility ATIS provides. Using multiple systems together plugs these observational gaps, providing redundancy if a station is down and a contingency if conditions rapidly change.

Building Your Total Weather Toolkit

In addition to ASOS, AWOS and ATIS, proficient pilots integrate a slew of other meteorological resources into their flight planning routines:

NWS Products – Forecasts, radar imagery, METARs and TAFs
Pilot Reports – First-hand observations from pilots in the air (PiREPs)
Flight Service Stations – Expert flight planners who provide weather briefings
Onboard Weather Radar – Real-time depiction of precipitation and storms

Airport diagrams, instrument approach plates, and other charts also integrate weather details like communication frequencies and runway equipment. And in winter, critical Runway Surface Condition (RSC) reports alert pilots to slippery surfaces.

Like Maria, all pilots remember the first time weather caught them off guard. But systematically leveraging all available systems and data minimizes surprises and enhances safety. The more obligations a pilot removes from the “single point of failure” list, the smoother the journey.

Final Approach: Maximize Your Weather Tools

Maria landed safely back in Dallas, reviewing the flight’s lessons on using multiple weather resources. She realized that like cockpit instruments, each system provides unique data points to guide pilots safely from origin to destination. Master aviators utilize all available tools to create seamless situational awareness.

On your next journey between the clouds, be sure to check airport diagrams for available weather systems. Retrieve local METARs and TAFs to supplement automated observations.

The more layers of information you integrate, the better the outcome. Smooth skies ahead!