NWS Jackson HWO Graphic Format/Definitions

NWS Jackson Hazardous Weather Outlook/Threat-Based Graphics

The Hazardous Weather Outlook (HWO) is designed to be a "heads up" to expected hazardous weather and its potential impact for the seven-day outlook period. It provides a first stop for users to find information on the potential for hazardous weather including timing, location, and impact. In conjunction with a text Hazardous Weather Outlook product, NWS Jackson produces coinciding images to provide a graphical depiction of threats, timing, and impacts. The text Hazardous Weather Outlook product is routinely issued twice a day - once during the early morning and again during the afternoon, and it is updated as needed. The issuance of the threat based graphics is contingent upon the existence of hazards in the upcoming forecast. Hazardous weather is defined as a meteorological or hydrologic event which has a significant chance of creating a harmful impact on people, property, or the economy.

The following hazards are included in the NWS Jackson HWO/graphics system:

• Severe Thunderstorms/Tornadoes
• Flooding
• Fog
• Excessive Heat
• Snow
• Ice Accumulation
• Frost/Freeze
• Hard Freeze
• Excessive Cold/Wind Chills
• Non-thunderstorm/Gradient Winds
• Dangerous Fire Weather Conditions
• Tropical Systems

Hazardous Weather Outlook Text Format

Bullets listed at beginning of each HWO segment provide readers with a quick assessment of the “what” and “when” in the Day 1 period. For example:

.DAY ONE...TONIGHT AND THURSDAY

FLOODING
THREAT…Extreme
TIMING…Tonight

SEVERE THUNDERSTORMS
THREAT…Enhanced
TIMING…Late Tonight and Thursday Morning

FOG
THREAT…Limited
TIMING…3 AM to 10 AM

Information for the Days 2-7 period will be more general and will not require bullets, but threat legend information will be given. Threat levels for hazards expected over the next seven days are defined at the bottom of the HWO text product. For example:

…THREAT LEGENDS…

*FOG*
Extreme...Widespread fog with near zero visibilities
Significant...Fog with visibilities less than or equal to ¼ mile likely
Elevated...Fog with visibilities less than or equal to 1/4 mile possible
Limited...Patchy areas of fog with visibilities less than or equal to 1/4 mile

*FLOODING*
Extreme…Confident in significant flooding
Significant…Significant flooding possible
Elevated…Confident in flooding
Limited…Flooding possible

Threat-Based Graphic Example

Hazard Category Definitions

With the exception of severe thunderstorms and tornadoes (which use the Storm Prediction Center scale), the color scale, categories, and definitions are based on feedback from our partners (including media, emergency managers, and social scientists). The threat levels (extreme, significant, elevated, and limited) are designated based on forecast confidence and potential impact.

Feedback

Your comments and suggestions for continued improvements to this product are welcome and can be sent to sr-jan.webmaster@noaa.gov