What is a Weather Hazard?

Severe weather hazards such as hurricanes, tornadoes, thunderstorms, hail, flooding, winds, winter weather, and more are dangerous weather phenomena that threaten life and property. Many of these phenomena are related to atmospheric conditions that can be monitored and forecast; an important task because weather hazards impact public safety and the economy. The National Weather Service (NWS) is responsible for issuing forecasts, watch and warning products for a variety of weather and water hazards.

Note: The descriptions in this section are informational only. Please see the NWS website for official information on all NWS topics. See NWS Weather-Ready Nation.

Impact Weather

A combination of observational datasets and numerical models are used in the warning process to identify and monitor all hazards. Once forecasters are highly confident that a specific weather scenario will cause significant impacts, they issue a warning as far in advance as possible for the areas expecting to be affected. The forecasters have the important and tedious role of sifting through a mountain of data, to determine what’s important before issuing the warning. It's not just the weather that is important, it’s the hazard’s impact as well.


Currently, forecasters must use multiple programs to issue a hazard warning product, depending on the type of event. The NWS uses some 122 different types of watches, warnings and advisories they send out for various weather phenomena. The variety of hazards statements issued by the NWS is indicated by different colors on a US map where, for example, lime green on this map represents a flooding threat for certain areas. Even for meteorologists, the list of NWS products can be overwhelming.

Click image for current US Hazards and see the associated help map color legend.

NWS Hazards Map Spring 2019
  Example of NWS past Hazards page. Click image for current NWS Hazards.

   What is Hazard Services?

About Hazard Services

Hazard Services (HS) is a powerful software package that modernizes the NWS warning process by vastly improving hazard communications. This new hazard warning application on the Advanced Weather Interactive Processing System (AWIPS) workstation will replace three existing hazard forecasting tools, each with its own interface, menu list, and process. This new software will streamline the forecasting of hazardous weather by unifying these applications into one with a single interface, thus unifying the forecast process and set of customization tools. HS is a multi-year, multi-phase effort involving many project partners.

"Our goal is to give the best possible tools to enable the weather service to apply those as skillfully as they do, to give the best possible warnings." Craig McLean, NOAA Oceanic and Atmospheric Research, October 2019.

Note: Hazard Services is not yet operational.

HS Unifying tools

Picture of the new Hazard Services application (on right) that upgrades and replaces legacy AWIPS warning tools.

Advantages of this tool are that it will:
• Become one common interface and warning process
• Preserve efficiency of existing applications and minimize training
• Better utilize a variety of models as input
• Have flexible output format options able to satisfy a variety of users
• Meet the demands of dissemination and decision support
• Foster collaboration among all stakeholders
• Incorporate new standards put forth by the Haz Simp project
• Meet the new and future needs of the NWS and NCEP National Centers issuing hazard messages

Leading-edge Science

Actionable information is meaningful information that is useful to decision-making or problem-solving. Criteria for actionable information -- the information is timely, relevant, and credible with a high level of accuracy. When fully realized and released, the HS application will serve as a conduit for leading-edge science and continue to get better.

   Project Development

Design Basics

HS has been structured and designed by software engineers alongside Weather Forecast Office (WFO) Forecasters, Hydrologists, NWS Information Technology Officers (ITOs) and Science and Operations Officers (SOOs), and others who routinely issue watches, warnings, and advisories. It has a display with user features that include logical and functional design considerations. In 2019, the system was in beta released to the NWS, in a limited number of offices for evaluation and feedback.

Development Path Applications

HS has been designed and built as the software vehicle to take the NWS into the era of Forecasting a Continuum of Environmental Threats (FACETs) program and Probabilistic Hazard Information (PHI). The severe thunderstorms and tornadoes warning tools in HS have been tested at the NOAA Hazardous Weather Testbed (HWT) for three years. These modernistic warning capabilities are emerging technologies for NWS operations.

NCEP National Centers (NC) have identified HS to aid their transition onto AWIPS, gain efficiency in forecast production, and serve as a collaboration vehicle between WFOs and NCs to better share hazardous weather information. Several NC water-weather hazards products are ideal candidates for HS; examples are the excessive rainfall outlook, the mesoscale precipitation discussion, and high seas warning. HS also meets the World Meteorological Organization (WMO) and International Maritime Organization (IMO) requirement for product modernization.

HS development efforts are progressing considerably and they fall primarily into three phases: (1) hazard information for Weather Forecast Offices (WFOs), (2) aviation-related hazard information for Meteorological Watch Offices (MWOs), and development activity aimed at the NCEP, and (3) FACETS using PHI.

Path I

NWS Weather Forecast Offices (WFO)

Hazards for Local Offices

To meet current and future NWS needs, HS replaces three AWIPS hazard applications with one enhanced software tool. This will allow forecasters to create, update, cancel, and expire hazards with advances software capabilities and use new standards for communicating risk.

Initial software has been developed for Hydrology and Winter Weather. Next: Marine, Hazard Simplification and changing output standards.

Path II

NCEP National Centers (NC) & Meteorological Watch Offices (MWO)

Hazards for NCs

Product Modernization to improve extreme precipitation forecasts for the Weather Prediction Center, the Ocean Prediction Center, the National Hurricane Center (NHC), and more.

Storm Surge Collaboration with NHC and WFOs.

Aviation-related hazards; example of a volcanic ash cloud in areas that could affect air-traffic routes.

Path III

Probabilistic Hazard Information (PHI)

PHI is the vehicle for operational probabilistic analysis and hazard information creation within the FACETs program. It is meant to communicate clear and simple hazardous weather information to serve the public and get the desired results to take action when required. By using Threats-In-Motion (TIM) concept, for example, has warning grids that update with-in minutes and move continuously with the path of the storm. TIM has the advantage of providing useful lead times for all locations downstream. And, includes other future-looking probabilistic information.

Applied Case with Customization Tools

Two inches of snow on the Washington DC Beltway at rush hour will be treated very differently than in rural Nebraska. Each of the three legacy applications independently created ways for the local forecaster to customize communication of hazard conditions. Instead of writing code for each scenario, we have built an HS framework that allows users to shape the system to their requirements. It is based on the easy-to-learn Python programming language for users to customize functionality and add new capabilities. This allows the system to handle diversity in requirements across forecast domains like a WFO or MWO as well as extend to new areas.

Developers Website

HS developers website is under construction at NOAA GSD, Boulder.

Featured Articles

• Weather Whisperer, NWS Des Moines: Improving Hazard Communication Aug 07, 2016

From GSD Communications Office:
GSD hosts forecasters to evaluate new Hazard Services Features July 16, 2019
Experimental Hazard Services system tested in flash flood forecasting environment Jul 16, 2015

Additional Objectives

The NWS is striving to ensure that the public is aware of and prepared for the variety of weather- and water-based hazards we experience across the country every day. A project called Hazard Simplification, or Haz Simp, is an NWS project (independent of HS) that will help. This involves a review and improvements in the areas of communication, namely: clear and focused messages, terms people understand, impact-based warning, and flexible output.

Note: This Haz Simp description is informational only. Please see the NWS website for official information on all NWS topics and see the Haz Simp Project.

Clear and Focused Messages

Hazard Simplification will help make hazard messaging as clear and focused as possible. HS is one of the vehicles to make necessary "repair and revamp" message changes guided by the Haz Simp project, where "repair" refers to a smaller hazard messaging change, and "revamp" refers to a larger change.

Terms People Understand

The NWS, and thus HS, are implementing these changes by consolidating and reformatting products.
– Consolidation means reducing the number of Watch, Warning, and Advisory (WWA) hazard products. Example.
– Reformatting means shortening, focusing, and clarifying the body text within the WWA messages. Example.

A What, Where, When (WWW) wording offers a shorter message, following a standard format to address the What, Where, and When of the hazard and recommended precautionary/preparedness actions.

Impact-Based Warning

HS will use Impact-based Warning (IBW) wording to communicate threats. It will focus on providing more information to media and emergency managers, facilitating improved public response and decision making; and meeting societal needs in the most life-threatening weather events. The impact-based warning will have tornado threat information attached to it as a quick means to provide users and partners with potential high impact signals that prompt faster risk assessment and protective action. Read more here, IBW.

Flexible Output

As a modernized platform, HS will allow for flexible output (legacy text, xml, kml, common alerting protocol (CAP), shape files, etc.), probabilistic and deterministic information, and will lay the foundation for moving the NWS deeper into the Impact-Based Decision Support Services, IDSS, and FACETs eras.

   Hazard Services Products (Example)

Here is a discussion of a hazard product, the warning message—a text product.
Note: Hazard Services is not yet operational, references are for introductory information only. The target release is AWIPS Operational Build 20.X.

Text Products

The information in the local text products includes location-specific forecast parameters for each hazard that also includes what, where, when, how much, how long, and it will contain descriptions of potential impacts.

Initial Test of Hazard Services

A development milestone was achieved with HS on 4/19/2019. An operational product was issued and transmitted from the NWS WFO Omaha (OAX) AWIPS HS. This was a real river flood product (or flood statement, called FLS) that was coordinated with the AWIPS Program Office, the AWIPS Network Control Facility (NCF), and NWS Central Region (CR) HQ. The transmission and dissemination was tracked to ensure it was distributed appropriately. This was the first end-to-end test of this type for HS. Everything worked well!

This test was one of several checks to prepare for the nation-wide deployment of HS in the future.

HS Initial Test of Text Message

Hazard Services Technical Details

If there is a significant desire to understand the complex process, then press button for a more in-depth discussion about the technical details. To keep this discussion simpler, skip to the next section.

Winter Weather

This series of images shows the gritty details. Here is an example of a meteorological threat or warning identified in an NWS tool (GFE) and brought into the HS application. The warning used in the example is a "winter weather" hazard warning.

This image shows how the current AWIPS CAVE GFE user interface is used to identify and define a winter warning A), with controls (left side), and the associated display (right side).

HS Winter Weather image A

In this image, on the left, B) shows the HS user interface. The defined winter hazard event is a winter storm warning. And, the image of a Winter Storm Warning text product on the right C) is an example of the type of warning message to be disseminated—a text product.

HS Winter Weather image B and C

Project Partners

The Hazard Services program is a joint effort between many partners...
— NOAA NWS Forecast Offices (WFO)
— AWIPS-2 Program Office
— NOAA NWS National Center Collaborators
— NOAA/OAR/ESRL/Global Systems Division (GSD)
— Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University (CSU)
— Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado-Boulder (UCB)
— Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) at the University of Oklahoma (OU)
— Raytheon AWIPS — Omaha, NE
— NOAA National Severe Storms Laboratory (NSSL)
— NOAA's Warning Decision Training Division (WDTD)
— and more

Global Systems Division


Raytheon logo

Raytheon Omaha

NOAA logo

AWIPS-2 Program Office

CIRA logo


CIRES logo

CIRES at CU-Boulder

NSSL logo


NWS logo


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and, other partners and collaborators.

   Contact Information

NOAA ESRL GSD Project Leads

National Centers

Nate Hardin photo...


Kevin Manross photo