Atm. Sci. 100 - Weekly Weather Forecasts

Survey of Meteorology

Weekly Weather Forecasts


Prof. Jon Kahl

The Assignment

Make a structured weather forecast each week for a location of your choice. Locations must be approved by Prof. Kahl before any forecasts are made. You will forecast for the same location throughout the semester.

The Forecasts

Each forecast will consist of the following elements:
  1. Maximum temperature*
  2. Justification for your maximum temperature forecast
  3. Minimum temperature*
  4. Justification for your minimum temperature forecast
  5. Wind speed at noon
  6. Justification for your wind speed forecast
  7. Wind direction at noon
  8. Justification for your wind direction forecast
*During the period from midnight - 11:59 PM, local time (that is, local at your forecast location)

The forecast must be submitted each week no later than 11:59 PM (Milwaukee time) on the day before the forecast day. The time will be recorded automatically when the forecast is submitted. Note that the justifications (the reasons) for your forecasts are equally important as the forecasts themselves.

When

Forecasts are to be made on Mondays. In other words, each Monday you will be making a prediction of Tuesday's weather at the location you have chosen. The forecast must be submitted before midnight. Forecasts submitted after midnight will not be accepted.

How

Make your forecast after examining real-time weather images such as those found on the Virtual Weather Map Room web site. Print out any images that you use to formulate your forecast. Submit your forecasts elecronically by visiting the Internet Weather Forecasting Activity website at www.uwm.edu/~kahl/Forecast. Follow the "Click here to submit your forecast" link, scroll down toward the bottom of the page and select the link for Prof. Kahl's class. Once you submit your forecast, print out the "Success" page that summarizes your forecast along with any relevant maps or charts you feel may be needed when verifying your forecast.

Verification

The "minimum temperature" and "maximum temperature" elements of all forecasts must be verified. "Verification" means determining the minimum and maximum temperatures that actually occurred. Verification also involves explaining any "busts", or significant errors in your forecast. For the purpose of this assignment, a "bust" is defined as a forecasted minimum or maximum temperature that differs from the actual minimum or maximum temperature by more than 5oF.

How to Verify

Go to the Weather Underground website at www.wunderground.com. Type your forecasting location into the search box at the top left of the page, for example "Milwaukee, WI", and click "Go". A new page for the location you specified will load. Pay attention to the left side of the page, and scroll down until you find a section labelled "Weather History for this Location". The max and min temperatures for yesterday will be listed. You should print this page and circle the observed max and min temperatures.

Explaining Busted Forecasts

An explanation of a bust consists of a paragraph describing what went wrong. These explanations generally require a few maps or charts to document the situation. For example:
Forecasted minimum temperature: 25oF,
Verified minimum temperature: 40oF.

A high pressure system was centered near my forecasting location. Because subsidence in high pressure systems generally causes skies to be clear, I thought it would be clear at night. The clear conditions at night would allow nighttime temperatures to become quite cold due to radiative cooling (see attached surface pressure map). However, it became cloudy at night and the clouds reduced the expected degree of cooling (see attached infrared satellite image).

Schedule

On Monday you make your forecast, on Tuesday you print out a few maps or charts in case you need them to explain any busts, and on Wednesday you verify your forecast. Specifically:

Monday:
  1. Go to the forecasting site ( www.uwm.edu/~kahl/Forecast). Click on the "Click here for access to real-time weather data" link. This will take you to the Virtual Weather Map Room where you can examine a variety of weather charts and maps and prepare your forecast.
  2. Print out a few charts or maps that you think are important to your forecast.
  3. Click on the "Click here to submit your forecast" link, select the link for Professor Kahl's class and submit your forecast.
  4. Print out the "Success" page and keep it together with the maps/charts that you printed out.
Tuesday:
  1. Print out a few maps or charts in case you need them to explain any busted forecasts.
  2. Relax.
Wednesday:
  1. Verify your forecast by determining the minimum and maximum temperatures that actually occurred at your forecasting location. Print this information out and attach it to your forecast and maps.
  2. If either your minimum or maximum temperature forecast was more than 5o different than the actual value, write a one-paragraph explanation describing the reason(s) for this difference.
  3. Attach the explanation(s), if any, to the other materials pertaining to this forecast.

What to Hand In

Each weekly forecast must contain:
  1. Your forecast (the printout of the "Success" page that appears after electronically submitting your forecast).
  2. Printouts of any images or data you used to make your forecast (in other words, Monday maps).
  3. Printouts of any images or data you printed out on Tuesday.
  4. Your forecast verification.
  5. Explanation of any forecast bust(s), if necessary.

Credit and Due Dates

You must complete eight weekly forecasts in order to receive credit for this assignment. Please hand in your forecasts as they are completed, in other words, each week. The last possible day to hand in forecasts is Monday Dec. 8.
Return to Professor Kahl's Atm. Sci. 100 web page