Forecasting General
Forecasting Tools
MOS
Winter Weather
Upper Air
100
This Forecasting sector provides weather forecasts, related weather stories and NWS advisories, watches and warnings.
What is the Broadcast Sector?
100
This is 1 iteration of a model running calculations and outputting data.
What is a Run?
100
This is how much time (generally) is covered by a MOS forecast product.
What is 3 Days?
100
This type of precipitation forms after falling through a shallow warm layer aloft and a deep freezing layer at the surface.
What is Sleet?
100
This is force is not considered when evaluating for geostrophic flow aloft.
What is Friction?
200
This is a forecasting timeframe at which forecasting products can be submitted with the most confidence. Generally 80% or better.
What is less than 24 hours?
200
This is the number of times per day that upper air observations are recorded (not including SPECIs).
What is 2 times?
200
This section of a MOS product covers ceiling height measurements based on pre-established categories of values in thousands of feet above the surface.
What is the CIG row?
200
This general indicator of winter precipitation is a measure of the 1000-500mb thickness.
What is the 540 line?
200
This type of vorticity occurs in the right exit region of a jet streak.
What is Anticyclonic Vorticity?
300
This forecasting method is used when a changing weather variable will continue to change at a similar rate.
What is Trending Forecasting?
300
This weather model a deterministic model with highly detailed computations, and is the greatest global forecast competitor to the GFS.
What is the Euro/ECMWF Model?
300
This row on a MOS product provides information on the likelihood for severe storms to occur over a 12 hour period.
What is the T12 row?
300
This is how much fetch is required for a lake effect snow event to occur.
What is 100+ km?
300
This trough orientation can signify the beginning or the end of a Mid-Latitude Cyclone.
What is Positively Tilted?
400
This level of the forecasting funnel is for considering how terrain and other nearby features may affect your forecast, and is generally on a scale less than 10 km.
What is the local/micro scale?
400
This model has a cutoff time of approximately 2 hours and 45 minutes.
What is the Global Forecast System?
400
This input on the VIS row would indicate visibility of 2-3 miles from the tower.
What is 4?
400
This type of force can act to destabilize or ruin a lake effect snow event, but is crucial for supercell storms to form.
What is Directional Shear?
400
This type of environment is associated with uniform temperature distribution, with atmospheric features remaining fairly static.
What is a Barotropic Environment?
500
This is the National Weather Service Statement of Purpose.

What is the “We will provide weather, water, and climate data, forecasts and warnings for the protection of life and property, and the enhancement of the national economy"?

500
This weather model runs every 6 hours, can forecast 84 hours out, and is a hydrostatic model.
What is the Global Forecast System?
500
This input on the OBV row would be used if sand was obstructing the view near the tower.
What is BL?
500
This type of force can enhance convergence on the lee side of the lake during a lake effect snow event, leading to a much stronger event.
What is the Friction/Orographic forcing?
500
These types of clouds can form as a result of weak/positive vertical velocities in conjunction with high relative humidity values.
What are Stratus Clouds?