A CIESE Realtime Data Project

Wind Effects - Teacher Guide: Lesson Plans

Wind Effects - A Case Study

Does weather have an impact on the height of tides?

Students will be able to:

  • use graphs and other data to determine the impact of a hurricane on the New Jersey coast
  • hypothesize what would happen if the hurricane made land fall at a different time

computers with Internet access
Student Worksheet
graph paper
colored pencils
optional: Excel

Hurricane Floyd Passes over Avalon, New Jersey
Between 4 and 5 pm on September 16, 1999, the center of Hurricane Floyd passed directly over an automated coastal monitoring station located on the beach in Avalon, New Jersey. The monitoring station is part of the New Jersey Coastal Monitoring Network operated by Stevens Institute of Technology, in Hoboken, New Jersey. Tropical Depression Floyd formed on September 7th in the western Atlantic. By September 10, Floyd reached hurricane strength and its center of circulation was located approximately 200 miles east-northeast of Barbuda in the northern Leeward Islands. Over the next two days Floyd moved west-northwest, strengthening to a category 4 hurricane. On the morning of September 15th, Floyd was located about 300 miles south of Wilmington, North Carolina. Floyd took a turn to the north during the day on the 15th and decreased in intensity to a category 2 hurricane. At 3 am EDT Floyd made landfall at Cape Fear, North Carolina. Please review the Stevens case study or NOAA case Study as it will serve as the basis for this lesson.

MLLW is mean lower low water, which is a site-specific datum determined by averaging the lowest of the 2 low tides that occur each day over a 19-year tidal epoch. For tide gages with less than 19-years of record, this datum is estimated using correlation with long-term tide gages.

In this lesson, students will use archived data from the Hurricane Floyd event to understand how wind can effect tide height.

1. Plot the following tide prediction data for Atlantic City, New Jersey, and create a line graph.

Tide Chart for Atlantic City, NJ (Steel Pier) - 9/14/99 to 9/17/1999

Date Day High Low High Low High
Time ft Time ft Time ft Time ft Time ft
9/14 Tue     04:59 0.49 11:14 4.53 17:29 0.68 23:28 3.98
9/15 Wed     05:38 0.76 11:58 4.39 18:18 0.92    
9/16 Thu 00:14 3.70 06:21 1.01 12:46 4.27 19:12 1.11    
9/17 Fri 01:05 3.47 07:09 1.20 13:39 4.19 20:11 1.21    
9/18 Sat 02:03 3.34 08:05 1.30 14:37 4.19 21:11 1.21    

2. Using the line same graph, plot the following measured tide data for Atlantic City, New Jersey. Use a different color to complete the line.

Measured for Atlantic City, NJ (Steel Pier) - 9/14/99 to 9/17/1999
Date Day High Low High Low High
Time ft Time ft Time ft Time ft Time ft
9/14 Tue     04:59   11:14   17:29   23:28  
9/15 Wed     05:38 1.3 11:58 4.9 18:18 1.5    
9/16 Thu 00:14 4.5 06:21 2.3 12:46 5.7 19:12 0.7    
9/17 Fri 01:05 2.6 07:09 0.1 13:39 3.5 20:11 0.1    
9/18 Sat 02:03 2.3 08:05 0.9 14:37 3.8 21:11      

3. Using the graph, answer the following questions on the Student Worksheet.

Were there any significant discrepancies between the predicted and measured water levels? Which day and time?
Can you hypothesize as to what might have occurred?

4. Review the following data recorded by the Coastal Monitoring Station presented below as time histories (Sept. 15 to Sept. 18). NOTE: The wave/tide gauge is located approximately 1/4-mile offshore in an average water depth of 13.1 ft MLLW.

5. Using the time histories, answer the following questions on the Student Worksheet.

Why would a sudden drop in barometric pressure be of significance? When did the drop occur?
What happened to the Wind Speed, Gusts and Direction at the same time of the sudden drop in barometric pressure?
What are all of these meteorological conditions an indication of?
Comparing the water level data you graphed to the meteorological conditions, why do you think the predicted water levels did not correlate with the measured water levels?
Was your hypothesis correct?

Satellite Images of Hurricane Floyd
Rutgers Site

6. Reviewing the predicted water levels and the meteorological information, how might the water levels been affected if the storm passed over Atlantic City at 11:30 am instead of 4:00 pm on September 16th? At 6:00 am?

7. The most damaging aspect of Hurricane Floyd was not felt along the New Jersey coast. Use the following links to determine which area of New Jersey received the most water damage from the storm.

U.S.G.S. Peak Streamflow Data
Raritan River at Bound Brook Site Map  
Elizabeth River in Elizabeth, NJ Site Map  
Hackensack River in New Milford, NJ Site Map  
East Branch Bass River, New Gretna, NJ Site Map  
This figure shows the total rainfall for a 2.5 day period between September 14th and 17th. Forty percent of the watershed was covered by 10 to 15 inches of rain. The red areas represent the heaviest amounts of rain.

*from the Rutgers Hurricane Floyd web page

1. Responses to questions on Student Worksheet.
2. Use links to real time data sources for your area. Do you think that the weather over the next week will impact the predicted water height? Explain why or why not. Revisit the sites after one week to see if the prediction was valid.

NOS Water Level Observation Network
Water Level Tidal Predictions
WWW Tide and Current Predictor
The Weather Underground