Department of Geological and Atmospheric Sciences

Meteorology 411 - Forecast Contest


Forecast Contest Log In page

Other forecasting links


A forecasting contest will be part of the required coursework for MTEOR 411 this semester. The contest will begin Monday, August 28. The contest will involve forecasting the daily Maximum and Minimum Temperature, and categorical amount of Precipitation and Snowfall for Des Moines, IA and a Floater City chosen by the instructor to represent an area where weather conditions are a challenge to forecast.


Forecasts will be made every MONDAY and WEDNESDAY for the period starting at 06 Z that night and lasting for the next 24 hours. Thus, for Des Moines during standard time, the 24 hour period for which the forecast is made will correspond to midnight-midnight, or the calendar day of Tuesday and Thursday. The floater city will be roughly similar, although local time may vary by one or two hours.

The floater city will be chosen by roughly 11 am on Monday and Wednesday, and posted on the front window of the map room, and will appear on the forecasting web page. We will not forecast on university holidays


Forecasts will be scored as follows:

  • 1 point is lost for each degree of error on the maximum and minimum temperature forecasts.
  • 4 points is lost for each category of error on precipitation and snowfall forecasts

For precipitation, the following categories apply:

  • 0 = 0.00 - Trace
  • 1 = Trace - .05 inch
  • 2 = .06 - .25 inch
  • 3 = .26 - .50 inch
  • 4 = .51 - 1.00 inch
  • 5 = greater than 1.00 inch

For snowfall, the following categories apply:

  • 0 = 0 - Trace
  • 1 = Trace - 2 inches
  • 2 = 2 - 4 inches
  • 3 = 4 - 8 inches
  • 4 = 8 inches or more

Some categories overlap, especially with snow. With snow, some reports are only given to the nearest inch, and the overlap method is more fair.


As an example of scoring, if I forecast MAX=35, MIN=22, Precip = 2, SNOW =2, and what verified is a MAX of 37, Min of 20, with a trace of precip and trace of snow, I would lose 2 points on the MAX, 2 points on the MIN, 4 points for being one category incorrect on precipitation (trace would be counted as category 1 to minimize error), and 4 more points on snowfall (for the same reason).


Students should enter their forecast by accessing the web site at prior to 7 pm on Monday and Wednesday. You can use any machine that has a web browser. You also can get to the site through a link from the ISU Weather Data page ( On the forecast site, you will first have to select the link to Portfolio. The first time you do this (Aug. 28) you will need to select create an account and give yourself a login and password (probably only if you've never been in this contest before). If it asks you for the portfolio password, use mt411. Normally, you just need to log in to portfolio (Meteorology 411 2017), and select the Forecast link at the top of the page. Enter your forecast parameters and click to submit them.

If there are computer problems, or you are unable to get to a computer, you may write your entries on a piece of paper and give it to me, or slip it under my door (Room 3025) before 7 pm. Scoring will be somewhat similar to golf -- the lower the score, the better. Results will be posted on the Internet and in the map room to encourage healthy competition. Be sure you do not forget to forecast, since PARTICIPATION will be a large part of the grade, and you are assigned persistence for your forecast when you forget. As long as you participate without any unexcused absences, your course grade will not be hurt by your forecasting performance. Good performance will result in a higher grade in the forecasting po rtion of the course. Improvement over the semester also will be considered in final grading for borderline grades. The semester will be split into two portions (before and after the midterm) so that a student performing badly at first can have a second chance to do well.

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Fall 2012