From: "Andrew J. Miller" <miller@umbc.edu>

Newsgroups: umbc.course.geog110h

Subject: Assignment for this week (#5, Friday, March 14)

Date: Tue, 11 Mar 1997 07:05:56 -0500

This week let's look at some weather patterns, using two primary categories: short-term weather disturbances such as extratropical or tropical cyclones, and larger-scale climatic phenomena such as El Nino. I expect this exercise will take us into next week as well, particularly the second part, as it has a bearing on global climates.

1. Short-term weather disturbances

Following Eric's lead, I thought we might analyze the weather patterns responsible for last week's flooding in the Ohio River valley. However I was frustrated by the fact that most of the web sites providing weather maps and satellite images do not catalogue these beyond 24 hours at the most. I have not been able to find a decent archive that would allow us to reconstruct the sequence of events that led to the floods. If anyone is able to find such an archive, please let me know and bring the information to class on Friday. In the meantime, you can access any of the bookmarked sites in my list from the class home page to look at current weather maps. On Friday we will try to focus on any visible cyclonic systems to try to see how the pressure, wind, temperature, and precipitation patterns are related. I have found that some of the commercial weather maps, such as the one produced by the Weather Channel, are easier for students to read. This one, for example:

http://www.weather.com/images/curwx.gif

A more general list from the same site is at the following link:

U.S. maps showing conditions and forecasts

http://www.weather.com/weather/us-maps/

There is some information on the flooding in Kentucky available from the following site, but you won't find weather information there to explain why it happened:

U.S. Geological Survey Water Resources Division Kentucky District http://130.11.24.1/

You can find some additional links from the main USGS water resource home page. This is worth looking at but I wouldn't spend too much time on it this week:

U.S. Geological Survey Water Resources Information

http://water.usgs.gov/

Another site with information about some notable weather events of the last several years is this one:

Weather events of 1993-1997

http://www.ncdc.noaa.gov/rcsg/weather-events.html

In what follows below, I recommend that you shouldn't try to do everything. For this week let's focus on fairly current weather examples. But for those interested in pursuing them, there are some very interesting resources available on severe weather phenomena, and I have tried to provide a decent set of links here.

You can find some fairly interesting discussions, as well as photos, of severe weather disturbances associated with tornadoes. The conditions that cause these to form are worth investigating. Here are a few reference links:

The University of Illinois online guide to meteorology has several modules associated with tornadoes and other severe storms, as well as hurricanes. Some of you have looked at these already; if you haven't, here is the general reference:

http://covis.atmos.uiuc.edu/guide/

There is a severe storm spotter's guide as well as a detailed account of a particular series of events from April 1996.

A cross-section through a tornado-producing supercell is illustrated at the following site:

http://www.atd.ucar.edu/rsf/VORTEX95/images/tall_tornado.html

At the next site is a tornado photo gallery. Not much in the way of technical information, but some interesting pictures:

http://taiga.geog.niu.edu/chaser/photo.html

Tropical cyclones (hurricanes):

The place to start definitely is with the list of frequently asked questions at the site below.

http://tropical.atmos.colostate.edu/

The NOAA address below provides a map showing storm tracks for all of the tropical cyclones in a particular year:

http://www.nhc.noaa.gov/index.html

The next address is for the NASA movie catalogue, which includes animations for some of last year's tropical cyclones:

http://rsd.gsfc.nasa.gov/rsd/movies/preview.html

The next one discusses field experiments proposed for 1996 on genesis of tropical cyclones, among others. It's a bit more technical than some of the other sites:

http://www.aoml.noaa.gov/hrd/HFP.html

The following are some additional links to sites that discuss tropical cyclones or that provide storm tracks, images, and animations. Some of these may be a bit out of date or no longer active:

http://www.typhoon.org.hk/

http://www.ssec.wisc.edu/data/index.html#special

http://www.ncdc.noaa.gov/pub/data/images/olimages.html

http://thunder.atms.purdue.edu/hurricane.html

http://oldthunder.ssec.wisc.edu/tropic/tropic.html

NASA advanced visualizations

http://globe.gsfc.nasa.gov/globe/sample/advanced.html

Visit this site for a perspective view of Hurricane Andrew in 1992, particularly the animation.

EL NINO/SOUTHERN OSCILLATION

El Nino is a recurring pattern of disturbance in tropical Pacific sea-surface temperatures, pressure, and winds that has far-reaching effects on global weather. An increasing amount of attention has been paid to this phenomenon in recent years.

The first document provides a good basic discussion.

Science Now, March 1994:

http://www.sirs.com/partner/snow/snow394/snow394.htm

The next site is sponsored by the research team at NOAA that is involved in an international project monitoring ocean surface conditions and associated meteorological variables.

El-Nino theme page:

http://www.pmel.noaa.gov/toga-tao/el-nino/home.html

Visit this site for an illustrated, well-written explanation of El Nino/Southern Oscillation and its global effects. If you feel ambitious, try selecting an El Nino and a non-El Nino year; then go back to the electronic atlas of storm tracks and compare summer or winter tracks between the two years.

You can go back to this site at Colorado State University for predictions and verifications concerning El Nino and its link to other global weather patterns:

http://tropical.atmos.colostate.edu/forecasts/index.html

This should be enough to keep everyone busy for a while!