Skip Navigation Linksweather.gov   
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
National Weather Service Binghamton, New York
Left nav bar  
 


Local forecast by
"City, St" or Zip Code

Forecast Terms

The National Weather Service issued forecasts for sky condition, temperature, wind and precipitation on a routine basis. The terminology used in these forecasts is quite variable. Listed below are descriptors of regularly used weather terms and their meanings to help give a better understanding of each forecast.

Sky Condition

The sky condition describes the predominant/average sky cover based on percent of the sky covered by opaque (not transparent) clouds. If a high probability of precipitation (60% or greater) is expected, then the sky condition may be omitted since it is inferred from the precipitation forecast.

Sky ConditionOpaque Cloud Coverage
Clear/Sunny1/8 or less
Mostly Clear/Mostly Sunny1/8 to 3/8
Partly Cloudy/Partly Sunny3/8 to 5/8
Mostly Cloudy5/8 to 7/8
Cloudy7/8 to 8/8


Temperature

The temperature in a forecast is used to describe the forecast maximum and minimum temperature, or in some cases, the temperature at a specific time.

Temperature DescriptionForecast Meaning
Around 50/Near 50A range of temperatures from 48 to 52
Lower 50sTemperatures of 50, 51, 52, 53, 54
Mid 50sTemperatures of 53, 54, 55, 56, 57
Upper 50sTemperatures of 56, 57, 58, 59
50sA range of temperatures from 50 to 59
50 to 55Temperatures of 50, 51, 52, 53, 54, 55


Wind

The wind describes the prevailing direction from which the wind is blowing with speeds in miles per hour. The wind forecast is included in the first three periods of the zone forecast.

Sustained WindSpeed Descriptive Term
0-5 mphLight/ light and variable wind
5-10 mph/ 10-15 mph/ 10-20 mphNone
15-25 mphBreezy (mild weather) Brisk or Blustery (cold weather)
20-30 mphWindy
30-40 mphVery Windy
40 mph or greaterStrong, dangerous, high, damaging (High Wind Warning Criteria)


Precipitation Probability

The probability of precipitation (POP), is defined as the likelihood of occurrence (expressed as a percent) of a measurable amount of liquid precipitation (or the water equivalent of frozen precipitation) during a specified period of time at any given point in the forecast area. Measurable precipitation is equal to or greater than 0.01 inches. Unless specified otherwise, the time period is normally 12 hours. The forecast area, or zone, is generally considered to be a county. NWS forecasters use such categorical terms as occasional, intermittent, or periods of to describe a precipitation event that has a high probability of occurrence (80%+), but is expected to be of an "on and off" nature.

POP PercentExpression of UncertaintyEquivalent Areal Qualifier
10 percent(none used)Isolated/ Few
20 percentSlight ChanceWidely Scattered
30, 40, & 50 percentChanceScattered
60 & 70 percentLikelyNumerous (or none used)
80, 90, & 100 percent(None used)Occasional, periods of, or none used


TIME PERIODS

Forecast Time PeriodNWS Definition (LST)
Today6am-6pm
This Morning6am-noon
This AfternoonNoon-6pm
This Evening6pm-midnight
OvernightMidnight-6am
Tonight6pm-6am



National Weather Service
Binghamton Weather Forecast Office
32 Dawes Drive
Johnson City, NY 13790
(607) 729-1597
Page last modified: February 06, 2009.
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities