Plain-English definitions of weather terms you might encounter in your daily briefings or in NWS forecasts — explained for hospitality operators, not meteorologists.
Weather conditions are favorable or neutral for guest arrivals. No significant deterrents present. The AI has assessed that today's forecast supports normal-to-strong traffic based on your location and time of year.
Some weather factors may affect traffic, but conditions aren't severely disruptive. Intermittent rain, marginal temperatures, or timing-specific issues (afternoon storms) fall into this category.
Significant weather deterrents are present. Severe storms, dangerous wind chills, heavy snow, ice, or extreme heat events that suppress outdoor movement. The AI expects meaningfully reduced guest counts.
A detailed written forecast issued by meteorologists at each local National Weather Service office. Unlike public forecasts, the AFD explains the reasoning behind the forecast — including uncertainty, competing models, and what conditions are being watched. GuestFlow reads the AFD every morning to generate your briefing.
AFDs are written in technical shorthand but contain the richest forecast information available for free. They're public domain and updated multiple times daily.
A less severe NWS alert than a Warning. Advisories indicate hazardous weather that may cause inconvenience but is not life-threatening — for example, a Wind Advisory for gusts up to 45 mph, or a Winter Weather Advisory for 1-3 inches of snow.
The leading edge of a cold air mass moving into a region of warmer air. Cold fronts typically bring a line of storms or showers followed by a rapid temperature drop, increased winds, and clearing skies. The pre-frontal period (before the front passes) is often warm and humid; post-frontal conditions can be dramatically colder within hours.
A forecast issued by the Storm Prediction Center (SPC) that categorizes the risk of severe thunderstorms — Marginal, Slight, Enhanced, Moderate, or High risk. These outlooks cover the contiguous U.S. and are updated several times daily.
The temperature at which air becomes saturated and moisture condenses. A better measure of how humid the air feels than relative humidity. Dew points above 65°F feel muggy; above 70°F feel oppressive; above 75°F are considered dangerous for prolonged outdoor activity.
A Watch means flash flooding is possible in the area. A Warning means flash flooding is occurring or imminent. Flash floods can develop within minutes of heavy rain, especially in urban areas with impervious surfaces.
A calculated index that combines temperature with wind (wind chill) or humidity (heat index) to reflect how hot or cold it actually feels to the human body. More useful than raw temperature for predicting guest behavior.
A brief, sudden increase in wind speed significantly above the average sustained wind. NWS forecasts list both sustained winds and gusts separately. Gusts are typically 30-50% higher than sustained winds.
How hot it feels when humidity is factored into the air temperature. The NWS issues Heat Advisories when the heat index reaches 100-105°F and Excessive Heat Warnings above 105°F.
Real-time reports of verified severe weather events submitted to the NWS by trained spotters, law enforcement, emergency managers, and the public. LSRs include tornado touchdowns, measured hail size, flood depth, and wind damage reports with timestamps and locations.
The U.S. government agency responsible for official weather forecasts, warnings, and observations. The NWS operates approximately 122 local forecast offices across the country, each responsible for a geographic region. All NWS data is public domain.
A 3-letter identifier for each NWS forecast office — for example, ILX (Lincoln, IL), OHX (Nashville, TN), or FFC (Peachtree City, GA). Each office covers a specific geographic region. GuestFlow uses your city's coordinates to automatically determine which office covers your location.
The percentage chance that measurable precipitation (at least 0.01") will occur at a given point during a specified time period. A 40% PoP doesn't mean it will rain 40% of the day — it means there's a 40% chance that any rain at all occurs at your specific location during that period.
An elongated area of high pressure in the upper atmosphere associated with sinking air, clear skies, and warm, dry conditions. The opposite of a trough. When a meteorologist says "a strong ridge will build over the region," expect sunny, stable weather.
The 30-year average temperature (or precipitation) for a specific location and date, calculated by NOAA from 1991-2020 data. Used as a baseline to determine whether current conditions are above or below normal.
Issued when a thunderstorm is producing or is expected to produce hail of 1" diameter or larger (quarter-size) or wind gusts of 58 mph or greater. A Tornado Warning is a separate, higher-level alert.
A GuestFlow-specific factor that compares today's forecast high against the 30-year seasonal normal for your location. If today's high is 8°F or more above or below normal, this is flagged and factored into the signal assessment.
An elongated area of low pressure in the upper atmosphere associated with rising air, clouds, and precipitation. The opposite of a ridge. Troughs are often associated with unsettled weather, storm systems, and cool temperatures.
How cold the air feels on exposed skin when wind is factored in. Wind accelerates heat loss from the body. Wind chill is only calculated for temperatures at or below 50°F and wind speeds above 3 mph. At 20°F with 20 mph winds, the wind chill is approximately 4°F.
A tiered system for winter weather alerts. A Watch means conditions are favorable for significant winter weather in the next 24-48 hours. A Warning means 6"+ of snow or significant ice is expected. An Advisory covers lower-impact events (1-4" of snow or light ice).