The F Scale vs. EF Scale and Storm Speeds with Types of Damage They Make

F Scale (Fujita Scale)

The original F Scale, developed by Dr. Tetsuya Fujita in 1971, categorizes tornadoes based on the damage they cause. It ranges from F0 to F5, with associated estimated wind speeds and damage descriptions:

F Scale Estimated Wind Speeds (mph) Typical Damage Description F0 40–72 Light damage: broken tree branches, minor roof damage, shallow-rooted trees pushed over. F1 73–112 Moderate damage: mobile homes pushed off foundations, roof surfaces peeled off, moving cars pushed sideways. F2 113–157 Considerable damage: roofs torn off frame houses, large trees snapped or uprooted. F3 158–206 Severe damage: entire stories of well-constructed houses destroyed, severe structural damage. F4 207–260 Devastating damage: well-constructed houses leveled, cars thrown, large debris become airborne missiles. F5 261–318 Incredible damage: strong frame houses lifted off foundations and carried considerable distances, automobile-sized missiles fly through the air.

EF Scale (Enhanced Fujita Scale)

Introduced in 2007, the EF Scale is a refined version of the F Scale, making use of more detailed damage indicators and degrees of damage to better estimate tornado wind speeds. The EF scale ranges similarly from EF0 to EF5 but with revised wind speed ranges:

EF Scale Estimated Wind Speeds (mph) Typical Damage Description EF0 65–85 Minor roof damage, broken branches, shallow-rooted trees pushed over. EF1 86–110 Roof surfaces peeled, mobile homes pushed off foundations, windows broken. EF2 111–135 Considerable damage: roofs torn from well-constructed homes, large trees snapped. EF3 136–165 Severe damage: entire stories of houses destroyed, significant structural damage. EF4 166–200 Devastating damage: homes leveled, cars thrown, large debris flying. EF5 Over 200 Incredible damage: strong foundation homes completely swept away, heavy vehicles airborne.

Comparison of Scales

• The EF Scale provides more accuracy with damage assessments incorporating 28 damage indicators (e.g. different types of buildings, trees, towers), compared to the original F Scale.

• EF Scale generally uses slightly lower wind speed estimates for the same damage level.

• EF Scale is now the official scale used by the National Weather Service.

Storm Speeds and Types of Damage

• Tornado wind speeds are the primary factor defining damage severity. Higher wind speeds correspond to more destructive events.

• EF0-EF1 (Light to Moderate Damage): Damage is generally cosmetic or minor structural. Examples include broken branches, damaged siding, and roof shingles blown off.

• EF2-EF3 (Considerable to Severe Damage): Damage to structures increases significantly. Roofs can be stripped, walls collapse, vehicles are displaced, and trees are uprooted.

• EF4-EF5 (Devastating to Incredible Damage): Complete destruction of well-built homes, devastation of neighborhoods, vehicles and debris become deadly projectiles.

Understanding these scales helps emergency planners, meteorologists, and the public assess tornado risks and impacts more precisely, enhancing safety and preparedness.

How to Read Weather Radar with GRLevel3 & GRLevel2 and All Its Capabilities

Weather radar is an indispensable tool for meteorologists and weather enthusiasts to monitor storms, precipitation, and atmospheric conditions in real-time. GRLevel3 and GRLevel2 are advanced radar display software programs designed for high-resolution weather radar data visualization. Understanding how to read these radars and utilize their full capabilities can enhance your weather analysis significantly.

Understanding the Basics of Weather Radar

Weather radars emit pulses of energy that bounce off precipitation particles. The returned signals provide information on:

• Reflectivity: Represents the intensity of precipitation (rain, snow, hail).

• Velocity: Shows the motion of precipitation particles toward or away from the radar, identifying wind patterns and potential rotation.

• Dual-polarization data: Offers detailed insight into precipitation type and particle shape.

GRLevel3 & GRLevel2 Overview

• GRLevel3: Primarily focused on Level III radar products from the NEXRAD radar network. It provides preprocessed radar imagery with various product displays like reflectivity, velocity, storm relative velocity, correlation coefficient, etc.

• GRLevel2: Displays Level II radar data, offering raw radar base products such as reflectivity, radial velocity, and spectrum width with more customization and higher data granularity, but requiring stronger computing resources.

How to Read Weather Radar in GRLevel3 & GRLevel2

1. Selecting Radar Site and Time

• Choose the nearest NEXRAD radar site for accurate local data.

• Use the timeline slider to analyze current or past radar scans.

2. Understanding Radar Products

• Reflectivity (dBZ): Color-coded from light (green) to intense (red/purple) precipitation. High values indicate heavy rain or hail.

• Velocity (knots): Shades of green and red indicate wind direction relative to the radar. Greens indicate motion toward the radar; reds indicate motion away.

• Storm Relative Velocity (SRV): Highlights rotation within storms useful for tornado detection.

• Correlation Coefficient (CC): Lower values often indicate non-meteorological objects like debris.

• Differential Reflectivity (ZDR): Helps differentiate precipitation types (rain vs. hail).

3. Utilizing Dual-Polarization Capabilities

• Combine multiple products like ZDR and CC to better identify hail or differentiate snow from rain.

• Use Hydrometeor Classification Algorithm (HCA) outputs for advanced precipitation typing.

4. Interpreting Radar Patterns

• Identify hook echoes or velocity couplets as potential severe weather indicators.

• Monitor storm structure and evolution with reflectivity and velocity overlays.

• Detect mesocyclones by spotting rotating velocity patterns.

5. Adjusting Display Settings

• Customize color scales to highlight desired features.

• Use layer stacking to overlay radar products for composite analysis.

• Set appropriate elevation angle slices to focus on surface or upper storm features.

Advanced Features and Tips

• Multi-Radar/Multi-Sensor Analysis: Use GRLevel3 to compare multiple radar sites for broader storm analysis.

• Looping Radar Scans: Animate radar images to observe storm movement, growth, or decay.

• Storm Tracking Tools: Utilize built-in polygon creation and tracking to analyze severe weather paths.

• Data Export & Integration: Export radar images or raw data for use in other GIS or meteorological applications.

Practical Applications

• Severe Weather Monitoring: Detect and track tornadoes, hail, and damaging winds.

• Rainfall Estimation: Gauge precipitation intensity and potential flooding.

• Aviation and Outdoor Planning: Assess weather hazards in real-time.

Summary

Mastering GRLevel3 and GRLevel2 radar software requires understanding radar fundamentals, interpreting various radar products, and leveraging dual-polarization data. By combining reflectivity, velocity, and other advanced radar fields, users gain a comprehensive insight into storm structure and behavior, improving weather analysis and situational awareness.

All Types of Winds

Winds are moving air caused by atmospheric pressure differences, which result from solar heating and the Earth's rotation. Various types of winds exist, categorized based on their origin, direction, and scale. Understanding these helps in meteorology, aviation, and environmental science.

1. Global Winds

Global winds are large-scale wind patterns that circulate around the Earth due to uneven heating of the planet’s surface.

• Trade Winds: Found in the tropics between 30°N and 30°S, these winds blow from the east toward the equator. They are steady and aid maritime navigation.

• Westerlies: Located in the mid-latitudes between 30° and 60° (both hemispheres), these winds blow from the west towards the east. They influence weather patterns in North America and Europe.

• Polar Easterlies: These cold winds blow from the east near the poles, moving toward lower latitudes.

2. Local Winds

Local winds are influenced by local geography and temperature differences over small areas.

• Sea Breeze: Occurs during daytime near coastlines. Cooler air moves from the sea to replace the rising warm air over land.

• Land Breeze: Happens at night, when cool air from the land moves toward the warmer sea surface.

• Valley Breeze: During the day, warm air rises up mountain slopes creating winds blowing upslope.

• Mountain Breeze: At night, cooler air descends slopes into valleys, producing downslope winds.

3. Periodic Winds

These winds change direction seasonally or daily based on cyclical factors.

• Monsoon Winds: Seasonal winds that reverse direction due to differential heating of land and ocean, bringing wet and dry seasons primarily in South Asia.

• Katabatic Winds: Occur when cold, dense air flows downhill from elevated plateaus or glaciers, often very strong and cold.

• Anabatic Winds: Upslope winds during the day caused by warm air rising along mountain slopes.

4. Storm Winds

Associated with weather disturbances and storms.

• Tornado Winds: Violently rotating columns of air extending from a thunderstorm to the ground, with extremely high wind speeds.

• Hurricane Winds (Typhoon/Cyclone): Large rotating storms with sustained winds exceeding 74 mph, formed over warm ocean waters.

• Squall Winds: Sudden, sharp increases in wind speed associated with thunderstorms or fronts.

5. Other Notable Winds

• Prevailing Winds: The most common winds in a particular region.

• Jet Streams: Narrow bands of strong wind in the upper levels of the atmosphere influencing weather systems and aircraft routes.

• Chinook Winds: Warm, dry winds descending on the lee side of mountain ranges in North America, capable of rapid snowmelt.

Understanding the diverse types of winds is crucial for weather forecasting, climate studies, and various practical applications in agriculture, transportation, and disaster management.

Micro Burst and Other Storm Winds

Microbursts and related storm winds pose significant hazards, especially to aviation, infrastructure, and communities. Understanding their nature and differences is essential for safety and preparedness.

Microburst

A microburst is a small, powerful downdraft that descends from a thunderstorm and spreads outward once it hits the ground. These winds can reach speeds up to 100 mph, causing localized but intense damage similar to a tornado.

Characteristics:

• Duration: Typically less than 5 minutes.

• Area affected: Usually less than 4 kilometers (about 2.5 miles) in diameter.

• Damage pattern: Straight-line winds radiating outward from the impact point.

• Cause: Rapid cooling of air due to evaporation or melting of precipitation within the storm, creating a dense downdraft.

Impacts:

• Aviation accidents due to sudden wind shear on takeoff or landing.

• Uprooted trees and downed power lines.

• Structural damage to roofs and weak buildings.

Other Storm Winds

Besides microbursts, several other storm wind phenomena are frequent and dangerous:

Downburst

A downburst is a larger-scale downdraft similar to a microburst but covers a broader area (up to 10 kilometers) and lasts longer. It also generates powerful straight-line winds.

Derecho

A derecho is a widespread, long-lived windstorm associated with a fast-moving line of severe thunderstorms. Winds often exceed 60 mph and can produce hurricane-force gusts over hundreds of miles.

Tornado Winds

Tornadoes produce rotating winds that can exceed 300 mph. Unlike microbursts and downbursts, their damage tracks are typically curved or circular due to rotational dynamics.

Gust Front

A gust front is the leading edge of cool air rushing down and out from a thunderstorm downdraft. It often causes sudden shifts in wind direction and speed and can trigger new storm development.

Safety and Preparedness

• Monitor weather updates during storm seasons.

• Understand wind warnings, especially for aviation and outdoor activities.

• Secure loose outdoor objects to prevent damage or injury.

• In case of severe winds, seek shelter indoors away from windows.

Conclusion

Microbursts and other storm winds represent a range of hazardous phenomena characterized by sudden, intense winds associated with thunderstorms. Their recognition and understanding are critical to mitigating damage and protecting lives.

How to Make Weather Radars with Alerts Using an API

Creating a weather radar system with alert capabilities involves integrating weather data APIs that provide radar images, precipitation data, and severe weather alerts. Below is a step-by-step guide to building this system:

1. Choose a Reliable Weather API

Select an API that offers:

• Radar imagery (or equivalent precipitation data)

• Real-time weather updates

• Severe weather alerts (e.g., thunderstorm, tornado, flood warnings)

Popular APIs include:

• NOAA Weather API

• OpenWeatherMap

• Weatherbit

• AccuWeather API

2. Set Up API Access

• Register on the API provider’s platform.

• Obtain your API key.

• Review the API documentation for endpoints related to radar data and alerts.

3. Fetch Weather Radar Data

Typical workflow:

• Use the radar imagery endpoint or precipitation data endpoint.

• Provide parameters: geographic coordinates (latitude, longitude), zoom level, and time frame.

• Request data in image (PNG, GIF) or raw data format (JSON, XML) depending on API.

Example (pseudo-code, using a REST API):

GET /radar?lat=40.7128&lon=-74.0060&zoom=8&apikey=your_api_key

4. Integrate Weather Alerts

• Use the API’s alerts endpoint.

• Fetch real-time or periodic alert data for the target location.

• Alerts typically include event type, severity, start/end time, and instructions.

Example alert JSON:

{
  "type": "Tornado Warning",
  "severity": "Severe",
  "start": "2025-05-09T14:00:00Z",
  "end": "2025-05-09T15:00:00Z",
  "description": "Tornado detected in the area. Seek shelter immediately."
}

5. Build Front-End Display

• Display radar images on a map interface using mapping libraries (Leaflet, Google Maps API).

• Overlay radar tiles or precipitation layers.

• Highlight areas with severe weather alerts.

• Use color codes or icons to indicate alert types and severity.

6. Implement Alert Notifications

• Setup webhooks or polling to check for new alerts.

• Notify users via:

  • Push notifications (web/mobile)

  • SMS or email alerts via integration with Twilio, SendGrid, etc.

  • On-screen modal or banner message.

Example notification logic (pseudo-code):

if new_alert:
    send_notification(alert.message)
    update_ui_with_alert(alert)

7. Optimize and Test

• Ensure timely updates by setting appropriate polling intervals or using API webhooks if available.

• Test radar imagery rendering across different devices and browsers.

• Verify alert triggering and notification accuracy.

Summary

By combining radar data and weather alerts from a comprehensive weather API, you can build a robust weather radar application with real-time alert capabilities. Choose the right API, handle data fetching properly, ensure clear visualization, and implement dependable user notifications for optimal performance.

NOAA Channels provide vital weather, oceanographic, and atmospheric information across multiple communication platforms. These channels include NOAA Weather Radio (NWR), NOAA Satellite broadcasts, and online streaming services that deliver real-time alerts, forecasts, and environmental data.

Key NOAA Channels:

• NOAA Weather Radio (NWR): A nationwide network of radio stations broadcasting continuous weather information directly from the nearest National Weather Service office. It provides alerts for severe weather, natural disasters, and emergency information.

• NOAA Satellite Channels: These transmit satellite data used by meteorologists and researchers for weather analysis, forecasting, and climate monitoring. Geostationary Operational Environmental Satellites (GOES) are instrumental in providing high-resolution imagery of weather systems.

• NOAA Coast Guard Weather: Specialized channels that offer maritime weather forecasts, warnings, and navigational information critical for safe operations at sea.

• NOAA Online Channels: Websites and digital feeds provide access to live updates, radar images, storm tracking, and scientific data crucial for professionals and the public.

NOAA channels are essential tools for disaster preparedness, scientific research, and everyday weather awareness, ensuring communities stay informed and safe.

NOAA Channel List

NOAA (National Oceanic and Atmospheric Administration) Weather Radio provides continuous weather information directly from the nearest National Weather Service office. Below is a general list of NOAA weather radio channels frequencies commonly used across the United States:

Frequency (MHz) Channel Number Use/Remarks 162.400 1 Primary NOAA Weather Radio Band 162.425 2 Secondary NOAA Weather Radio Band 162.450 3 NOAA Weather Radio Channel 3 162.475 4 NOAA Weather Radio Channel 4 162.500 5 NOAA Weather Radio Channel 5 162.525 6 NOAA Weather Radio Channel 6 162.550 7 NOAA Weather Radio Channel 7

Notes:

• These seven frequencies cover NOAA Weather Radio broadcasts nationwide.

• Channel availability may differ depending on your geographical area.

• NOAA Weather Radio broadcasts 24/7, including weather alerts, watches, warnings, forecasts, and emergency information.

• In addition to weather updates, some NOAA stations broadcast marine information and public safety alerts.

For specific local frequencies and station locations, please consult your nearest National Weather Service office or official NOAA resources.

NOAA With S.A.M.E. and How It Works

The National Oceanic and Atmospheric Administration (NOAA) utilizes the Specific Area Message Encoding (S.A.M.E.) technology to deliver targeted weather and emergency alerts. S.A.M.E. is a digital coding system that enables the dissemination of precise warnings and notifications to specific geographic areas, improving the efficiency and effectiveness of public safety communications.

What is S.A.M.E.?

S.A.M.E. stands for Specific Area Message Encoding. It is a protocol used to encode information about emergency alerts including weather warnings, advisories, and other critical public safety messages. This standard enables devices such as NOAA Weather Radios and emergency alert systems to receive messages relevant only to pre-selected regions, reducing unnecessary alerts in unaffected areas.

How S.A.M.E. Works

1. Alert Creation: When a weather event or emergency arises, NOAA or authorized agencies create a warning or alert message.

2. Message Encoding: The message is encoded using S.A.M.E., which embeds codes that specify the type of alert, geographical area(s) affected, and duration of the warning. These geographic codes correspond to specific counties or regions.

3. Broadcasting: The encoded message is transmitted via NOAA Weather Radio stations. The transmission includes a digital header with the S.A.M.E. codes followed by the audible message.

4. Device Reception: Weather radios and emergency receivers equipped with S.A.M.E. decoding capabilities continually monitor broadcasts. Upon detecting a matching geographic S.A.M.E. code, the device activates an alert tone and presents the message to the user.

5. Alert Delivery: The alert informs residents of imminent or ongoing emergencies, allowing timely action to safeguard life and property.

Benefits of S.A.M.E.

• Targeted Alerts: Only residents in affected areas receive notifications, minimizing alert fatigue.

• Automated Response: Devices automatically activate when an alert is relevant, ensuring prompt attention.

• Multi-Hazard Application: S.A.M.E. supports varied alerts ranging from tornado watches to chemical hazards.

• Reliable Communication: Delivered through NOAA Weather Radio’s robust network, ensuring coverage even during power outages.

NOAA's use of S.A.M.E. enhances community preparedness by delivering precise, timely, and actionable emergency information tailored to specific locales. This technology plays a critical role in improving public safety and response during hazardous weather events and emergencies.

All Types of NWS & NOAA Alerts and Amber Alerts

The National Weather Service (NWS) and the National Oceanic and Atmospheric Administration (NOAA) provide a range of alerts to inform the public about potentially hazardous weather conditions, natural disasters, and emergencies. Additionally, Amber Alerts serve as urgent child abduction warnings issued to the public. Understanding these alerts is crucial for timely responses and safety.

NWS & NOAA Weather Alerts

The NWS and NOAA issue various alerts based on the severity and type of weather or hazard. These alerts are categorized as advisories, watches, warnings, and statements.

1. Advisory

• Indicates weather or hazardous conditions that are less severe but may still cause inconvenience or unusual conditions.

• Examples: Dense Fog Advisory, Wind Advisory, Heat Advisory.

2. Watch

• A watch means conditions are favorable for a particular hazard to develop.

• Remain alert and prepared to take action if a warning is issued.

• Examples: Tornado Watch, Flood Watch, Severe Thunderstorm Watch.

3. Warning

• A warning means a hazardous weather or dangerous event is occurring or imminent.

• Immediate action should be taken to ensure safety.

• Examples: Tornado Warning, Flash Flood Warning, Hurricane Warning.

4. Statement

• Provides additional information about a recent or ongoing weather event.

• Useful for awareness but does not require immediate action.

• Examples: Weather Statement, Flood Statement.

Types of Specific NWS/NOAA Alerts

• Tornado Watch/Warning: Notification of potential or occurring tornadoes.

• Flood Watch/Warning: Alerts for possible or occurring flooding.

• Severe Thunderstorm Watch/Warning: Warnings about storms with damaging winds or hail.

• Hurricane Watch/Warning: Alerts regarding hurricanes, tropical storms, or typhoons.

• Winter Weather Advisories/Warnings: Includes snow, ice, and cold warnings.

• Heat Advisory/Warning: High temperature alerts to prevent heat-related illnesses.

• High Wind Warning: Issued when sustained winds or gusts reach dangerous levels.

• Fire Weather Watch/Warning: Alerts related to conditions favorable for wildfires.

• Coastal Flood Advisory/Warning: Notifications about high tides or storm surges affecting coastal areas.

NOAA Weather Radio Alerts

NOAA Weather Radio (NWR) broadcasts these alerts 24/7. It is recommended to have a dedicated NWR receiver for receiving alerts, especially in areas prone to severe weather.

Amber Alerts

Amber Alerts are urgent bulletins issued to inform the public about child abductions. The goal is to engage the community’s help in locating and safely recovering abducted children.

Key Characteristics of Amber Alerts:

• Issued by law enforcement agencies connected to the National Center for Missing & Exploited Children (NCMEC).

• Alerts include descriptions of the abducted child, suspected abductor, and any pertinent vehicle information.

• Delivered through multiple channels: radio, television, highway signs, and wireless emergency alerts.

• Require immediate public attention and action if a sighting or information is reported.

Summary

Awareness of NWS and NOAA alerts enables individuals and communities to prepare for and respond effectively to adverse weather conditions. Amber Alerts, on the other hand, are vital tools for protecting children and engaging public assistance in emergencies. Always stay informed through official channels and take recommended safety measures when alerts are issued.

Weather Radar Colors and All Their Meanings

Weather radar systems use a color-coded scheme to represent the intensity and type of precipitation detected. Understanding these colors helps interpret the radar imagery accurately for weather forecasting or safety planning. Below is an explanation of common radar colors and what they mean:

1. Green Shades

• Light Green: Light rain or drizzle.

• Medium/Dark Green: Moderate rain.

Green generally indicates lighter precipitation. The darker the green, the heavier the rain.

2. Yellow Shades

• Light Yellow: Moderate to heavy rain.

• Dark Yellow: Heavy rain.

Yellow signals increasing rainfall intensity, often indicating moderate showers.

3. Orange and Red Shades

• Orange: Heavy rain, possible thunderstorms.

• Red: Very heavy rain, intense thunderstorms, potential severe weather.

These colors warn of strong storms capable of causing hazardous conditions like flash flooding and lightning.

4. Pink and Purple Shades

• Pink: Mix of rain and snow, sleet, or freezing rain.

• Purple: Intense snow or mixed precipitation.

These colors indicate wintry precipitation, often signaling hazardous travel conditions.

5. White and Blue Shades

• Light Blue: Light snow.

• Medium/Dark Blue: Moderate to heavy snow.

• White: Very heavy snow or blizzard conditions.

Blue and white colors represent snowfall intensity, with brighter shades indicating more severe snow events.

6. Gray or Black Areas

• Often signify no precipitation or very light precipitation below radar detection thresholds.

Additional Radar Indicators:

• Hail: Sometimes displayed as magenta or very bright colors on specialized radar products.

• Radar Anomalies: Ground clutter (fixed echoes) can appear as random colored spots, often near radar stations.

Summary Table

Color Precipitation Type Intensity Light Green Light rain Light Dark Green Moderate rain Moderate Yellow Moderate to heavy rain Moderate to heavy Orange Heavy rain, possible storms Heavy Red Very heavy rain, severe storms Very heavy, potentially severe Pink Mixed precipitation (rain/snow) Variable, wintry mix Purple Intense snow or mixed Heavy snow or freezing rain Blue Snow Light to heavy snow White Very heavy snow/blizzard Extremely heavy snow Gray/Black No precipitation None or very light

Understanding these colors on your weather radar app or website provides critical information for safety and preparedness during various weather events.

How to Find Tornadoes on Weather Radar

1. Understand Radar Basics
   Weather radar detects precipitation and wind patterns. Tornadoes themselves aren’t directly visible but can be inferred from radar signatures.

2. Look for Hook Echoes
   On radar reflectivity, a hook-shaped extension on the edge of a thunderstorm indicates a rotating updraft known as a mesocyclone, often associated with tornadoes.

3. Identify Velocity Couplets
   Doppler radar measures wind velocity toward or away from the radar. Tornadoes create a tight couplet of inbound and outbound winds close together, indicating strong rotation near the ground.

4. Check Storm Relative Velocity
   This radar product highlights wind rotation relative to the storm movement, making it easier to pinpoint mesocyclones and potential tornado genesis areas.

5. Monitor Storm Structure
   Tornadic thunderstorms exhibit supercell characteristics—well-defined updrafts, hook echoes, and strong rotational velocity signatures.

6. Use Multiple Radar Products
   Combine reflectivity with velocity, storm-relative velocity, and sometimes dual polarization data for enhanced detection of debris signatures (debris balls), which confirm tornado on the ground.

7. Stay Updated on Warnings and Storm Reports
   Official tornado warnings and spotter reports provide context and verification beyond radar indications.

By carefully analyzing reflectivity patterns, velocity data, and storm structure on radar, you can effectively identify and track tornado threats before and during severe weather events.

How to Find Wind Speed and Hail in a Storm on Weather Radar

Understanding Weather Radar Basics

Weather radar primarily detects precipitation by sending out radio waves that bounce off raindrops, hailstones, or snowflakes. The returned signal gives information about the location, intensity, and movement of precipitation within a storm system.

Identifying Wind Speed Using Doppler Radar

1. Doppler Velocity Data
   Weather radars equipped with Doppler technology measure the velocity of precipitation particles moving toward or away from the radar.

   • Look for velocity maps or storm-relative velocity products.

   • Wind speed is inferred by measuring the shift in frequency of returned signals caused by motion.

   • Areas where velocity colors rapidly change from inbound (toward radar) to outbound (away from radar) indicate strong wind shear or rotation.

2. Interpreting Velocity Values

   • High wind speeds often register as brighter greens (inbound) or reds (outbound) on velocity maps.

   • Tornadic rotation or microbursts appear as velocity couplets, with opposing velocity colors adjacent to each other.

   • The maximum indicated velocity can offer an estimate of the wind speed within the storm but interpret with caution due to radar limitations.

Detecting Hail Using Radar Products

1. Reflectivity Intensity

   • Hailstones cause very high reflectivity levels on radar due to their size and density.

   • Reflectivity values exceeding 55 to 60 dBZ often indicate hail presence.

   • Very large hail can generate reflectivity values above 70 dBZ.

2. Dual-Polarization Radar Products
   Modern radars provide additional hail detection tools through dual-polarization technologies:

   • Differential Reflectivity (Z_DR): Lower values in high reflectivity areas suggest hail because hailstones are generally spherical, providing near-equal returns in horizontal and vertical pulses.

   • Correlation Coefficient (CC): Values significantly below 0.90 indicate mixed precipitation types, like hail mixed with rain.

   • Using these parameters helps differentiate hail from heavy rain.

3. Hail Size Estimates

   • Algorithms like the Maximum Expected Hail Size (MESH) product combine reflectivity, Z_DR, and other radar variables to estimate hailstone size.

   • MESH outputs are often highlighted on radar display overlays for easy identification.

Summary Checklist

Parameter Radar Product Key Indicators Wind Speed Doppler Velocity High velocity values, velocity couplets indicating rotation or shear Hail Presence Reflectivity Reflectivity > 55 dBZ Differential Reflectivity (Z_DR) Low Z_DR in high reflectivity areas Correlation Coefficient (CC) CC < 0.90 indicates mixed precipitation MESH Estimates hail size, highlight severe hail

Additional Tips

• Access radar tools offered by the National Weather Service or specialized weather software to view dual-polarization products.

• Always consider radar location and distance, as radar beam elevation and range can affect detecting surface-level wind speeds and hail accurately.

• Combine radar data with ground observations or storm spotter reports for confirmation.

Using these radar products and interpretation techniques allows meteorologists and storm watchers to effectively identify wind speeds and hail within storms, aiding in timely warnings and safety measures.

How to Be a Storm Spotter With Amateur Radio and SKYWARN

Becoming a storm spotter is an important way to support your community by providing real-time severe weather reports to the National Weather Service (NWS). Utilizing amateur radio enhances communication reliability, especially during critical situations when other systems may fail. Here’s a step-by-step guide to becoming an effective storm spotter with amateur radio and SKYWARN.

1. Understand the Role of a Storm Spotter

Storm spotters observe and report weather conditions such as tornadoes, hail, high winds, flash flooding, and other severe weather phenomena. Accurate, timely reports help meteorologists confirm radar data and issue warnings.

2. Join SKYWARN

SKYWARN is a nationwide volunteer program coordinated by the NWS.

• Visit your local NWS office or website to find a SKYWARN training schedule in your area.

• Participate in free training sessions covering storm recognition, safety, and reporting procedures.

3. Get an Amateur Radio License

Amateur radio (also called ham radio) provides a reliable communication channel for storm spotters.

• Study for the FCC Technician Class license, the entry-level amateur radio license, which allows access to essential frequencies.

• Take the licensing exam at a local testing session or through a volunteer examiner.

4. Acquire and Understand Amateur Radio Equipment

• Purchase a reliable VHF/UHF handheld transceiver (HT) or mobile radio capable of operating on local SKYWARN frequency repeaters.

• Learn basic radio operation, including how to use repeaters, emergency channels, and proper radio etiquette.

5. Connect With Local Amateur Radio and SKYWARN Groups

• Join ham radio clubs and SKYWARN net groups in your region. These groups conduct regular net operations (scheduled radio check-ins) and exercises.

• Build relationships with experienced spotters and emergency personnel.

6. Participate in Training and Drills

• Attend refresher courses and advanced training offered by the NWS or amateur radio clubs.

• Take part in SKYWARN nets and emergency communication drills to practice protocols and reporting.

7. Learn Effective Spotting and Reporting Techniques

• Identify cloud formations, rotation signatures, types of precipitation, and storm movement.

• Know the standardized report format required by the NWS, typically including location, time, type of phenomenon, size (hail/tornado), and damage (if any).

• Focus on safety: spot from safe locations and communicate without distraction.

8. Activate During Severe Weather

• Monitor weather conditions using radio, internet weather services, and NWS alerts.

• When severe weather threatens, activate your amateur radio and SKYWARN participation.

• Collect and transmit accurate, concise observations to the NWS via your amateur radio network.

9. Continue Learning and Growing

• Stay current with weather technology, spotting techniques, and communication best practices.

• Attend annual SKYWARN update classes and enhance your ham radio skills.

• Share your knowledge with new spotters and community members.

Summary: Becoming a storm spotter with amateur radio and SKYWARN involves education, licensing, hands-on practice, and a commitment to safety and accuracy. By combining weather knowledge with effective radio communication, you become a critical link in protecting lives and property during severe weather.

Skywarn Net Preamble for Net Control Guidelines

Welcome to the Skywarn Net. This net operates to support the National Weather Service by providing timely and accurate weather spotter reports during severe weather events. As Net Control, you play a crucial role in maintaining clear, concise, and professional communications to ensure the safety and effectiveness of our operations.

Net Control Responsibilities:

1. Establish Control Early: Begin the net promptly at scheduled times or immediately upon activation. Announce the net's purpose and remind all participants of the operational guidelines.

2. Maintain Order: Control the flow of communications. Allow one station to speak at a time, and avoid overlapping transmissions. Use clear, plain language and avoid unnecessary jargon.

3. Prioritize Safety Reports: Prioritize incoming weather spot reports. Facilitate the relay of critical information to the appropriate authorities swiftly and accurately.

4. Manage Check-Ins: Log all participating stations with call signs and locations. Confirm each station’s readiness to provide spotter reports.

5. Handle Emergencies: Be prepared to handle emergency traffic immediately. Grant priority to stations reporting life-threatening conditions or requests for assistance.

6. Keep the Net Brief and Focused: Encourage concise transmissions. Discourage unrelated conversation to keep the net efficient and focused on weather-related reports.

7. Use Standardized Procedures: Follow established Skywarn protocol, including proper use of phonetics, timing, and format for reports.

8. Provide Regular Updates: Issue periodic updates and, when appropriate, shift changes for Net Control operators.

9. Close the Net Properly: When the net concludes, officially close the session, thank participants for their professionalism and dedication, and provide information on when the net may resume.

By adhering to these guidelines, Net Control operators ensure that the Skywarn Net remains a vital link between spotters and the National Weather Service, delivering high-quality information that can save lives and property.

Radio Channels For Nets With or Without a FCC Radio Communication License

1. 462.5625 FRS 1

2. 151.820 MURS 1

3. 146.520 HAM SIMPLEX ( L )

4. 462.550 GMRS 1 ( L )

   CTCSS IS NOT REQUIRED

5. POC GLOBAL-PTT

6. POC ZELLO