Weather Products

U. S. Weather Observations

These are observations of current conditions. Upper air observations using radiosondes occur every 12 hours (6 AM and 6 PM). Surface observations and the wind profiler occur every hour.

Upper Air Analysis and Profiles

Upper air analysis have many uses. Each map displays different aspects of the weather situation. The 300 mb map defines the jet stream position. The 500 mb map illustrates the positions of and shortwaves, which help produce cloudiness and precipitation. The 850 mb map can be used to indicate where temperature and moisture advection are occuring.

Soundings illustrate the change in temperature, dewpoint, and winds in a column through the atmosphere. Wind profilers show the same column of winds changing through time.

Satellite Images

Satellite observations display existing cloud conditions. The visible picture gives a "camera shot" from space during the day. The infrared measures temperatures of the cloud tops (useful during the day or night). Water vapor shows the percentage of water vapor existing through the atmosphere.

Surface Weather Observations

U. S. Forecast Maps

These maps display computer model forecasts of upper air and surface conditions from 12 hours to 10 days ahead based on the initial time. These are run once 12 hours (6 AM and 6 PM). Data is usually available 5-6 hours after the initial time.

Surface progs are manually drawn maps based on computer model data. These maps show the position of fronts and probable areas of precipitation 12 and 24 hours from the initial time.

Model Forecasts

Computer models use current weather conditions to project how conditions willchange in the coming hours and days. The model output must be interpreted, since few normal surface features are drawn on the maps. These are computer projections and not always correct. These are good to use for a guide but adaptations must be made.

Paul's Favorite Products

Revised: 9 Jan 1998
Send comments and suggestions to:
Doug Yarger (doug@iastate.edu) or Pete Boysen (pboysen@iastate.edu)
Copyright © 1996, Iowa State University, All Rights reserved