Hurricane Web Assignment

1. Hurricane Formation

Tropical Cyclones form over warm surface water (greater than 27oC) . However, they do not form near the equator where the Coriolis force is weak. Remember that the Coriolis force plays a crucial role in rotation around an area of low surface pressure.The 2 maps below indicate the ocean surface temperature in August 1999 and February 2000. Temperatures over 28oC are indicated by orange, and temperatures over 27oC are indicated by green shading.

Question 1. Which of the locations labeled (A-G) are most likely to form tropical storms in February (top picture)?

Question 2. Which of the locations labeled (A-G) are most likely to form tropical storms in August (bottom picture)?

2. Hurricane Paths

Atlantic Hurricanes typically move from east to west initially, within the region of the trade winds (See Chapter 7 to review global wind belts). Often these hurricanes eventually veer northward, and then eastward as shown in these hurricanes below:
Interpretation of these Track Charts at Unisys Tropical Page
(Bill 2009, Fabian 2003, Cindy 1999, Floyd 1999)

Hurricane Bill

Hurricane Floyd

Hurricane Fabian

Hurricane Cindy
More about these Track Charts at Unisys Tropical Page

Question 3. What surface pressure feature is associated with this right-curving path? (see Chapter 7 to review global circulation patterns)
Current Sea Level Pressure Chart with surface winds (generally similar to conditions during hurricane season).

Question 4. Why would hurricanes be expected to weaken as they move poleward? (There may be more than one factor which might contribute to decreased hurricane intensity)

 

3. Hurricane Classification (Saffir-Simpson Scale)

The most famous Atlantic hurricanes include Andrew (1992), Hugo (1989), and Gilbert (1988).
Description and imagery of these "Classic Hurricanes"

Question 5. All of these storms were classified as Category 5 storms (the strongest on the Saffir-Simpson scale). What was the maximum sustained wind speed for each of these hurricanes?

Question 6. Identify the most recent Category 5 Atlantic hurricane.

2009 Hurricanes

2008 Hurricanes

2007 Hurricanes

2006 Hurricanes

2005 Hurricanes

2004 Hurricanes

2003 Hurricanes

2002 Hurricanes

4. Atlantic Hurricanes and El Nino

Although Atlantic hurricanes are not directly affected by the El Nino phenomenon which occurs in the equatorial Pacific Ocean, El Nino influences how active an Atlantic hurricane season is.

Question 7. Compare the number of hurricanes and named storms in 1997 (a strong El Nino year) with the number in 1998 and 1999 (La Nina years).

 

5. Hurricane Forecasts

 

Colorado State's Seasonal Hurricane Prediction

Question 8. How many tropical storms are predicted for this season? How many hurricanes? Do these predictions reflect greater than normal hurricane activity?

 

As of July 11, 2003, Tropical Storm Claudette, above, had not reached hurricane strength. In this IR image, the red and white areas indicate the cold (high) cloud tops of the storm as it passes Cuba and Mexico's Yucatan Peninsula. Below, is the storm's track to date and its forecast track.

The information below indicates the predicted position and sustained wind speed predicted starting from 15Z on July 15. Remember that 65 knots is the minimum value for a hurricane.

INITIAL 11/1500Z 21.6N 87.4W 50 KT
12HR VT 12/0000Z 22.9N 88.9W 50 KT
24HR VT 12/1200Z 24.3N 90.4W 55 KT
36HR VT 13/0000Z 25.2N 91.5W 60 KT
48HR VT 13/1200Z 25.8N 92.6W 65 KT
72HR VT 14/1200Z 26.0N 95.0W 70 KT
96HR VT 15/1200Z 26.0N 97.5W 65 KT...INLAND
120HR VT 16/1200Z 26.0N 100.0W 20 KT...DISSIPATING

 

Question 9. When Tropical Storm (Hurricane) Claudette made landfall in southern Texas, where was the highest storm surge likely (i. e. north of the landfall, at the landfall, south of the landfall)?