Lesson: Hurricanes and Hot Towers
Global Precipitation Measurement Mission
Developed by
Kristen WeaverGPM Master Teacher
NASA Goddard Space Flight Center
Guiding QuestionsGuiding Questions
• Storms: Have you ever experiences a hurricane or a severe storm? What was it like?
• Hurricane Damage: What are some of the effects of hurricanes?
• Hurricane Causes: What conditions cause hurricanes to form?
• Predicting the Path: How do we predict the path of a hurricane? How have those predictions changed over time, especially with the use of satellites?
• Using Satellites: How can satellites look inside a hurricane?
• Predicting the Intensity: What can “hot towers” in a hurricane tell us about its intensity?
EngageEngage• Have you ever experienced a hurricane or a severe
storm? What was it like?
Images from Microsoft Office ClipArt
Somerset Point in Pinopolis, SC along the shores of Lake Moultrie during Hurricane Gaston on August 29, 2004
Image courtesy of Mike Stafford, http://www.erh.noaa.gov/chs/pictures.shtml
North Roosevelt Boulevard, Key West, Florida during Hurricane Wilma, October 2005
Image source: http://www.srh.noaa.gov/key/?n=wilma
Winds and Storm SurgeWinds and Storm Surge
Before and AfterBefore and After
In the top image, taken in 1998, notice the pier, pier house, and the antebellum house. The bottom image shows the same location on August 31, 2005, two days after Hurricane Katrina made landfall. This photo shows the complete destruction of these landmarks.
(Image and text from http://coastal.er.usgs.gov/hurricanes/katrina/photo-comparisons/mainmississippi.html)
Effects of a HurricaneEffects of a Hurricane
9th Ward flooding caused by Hurricane Katrina
Damage caused by Hurricane Katrina
Images from: http://sos.noaa.gov/Education/forecast.html
What causes hurricanes?What causes hurricanes?
Three Factors of Hurricane FormationThree Factors of Hurricane Formation
What do hurricanes need to be able form?
• Warm water (at least 80°)
• Moist Air
• Converging Winds
Image source: http://scijinks.jpl.nasa.gov/hurricane
Where do hurricanes form?Where do hurricanes form?
The storms get what they need from the warm equatorial waters off the coast of Africa, and then blow west toward the U.S. coast.
Hurricane DamageHurricane Damage
Because hurricanes can be so damaging, we want to be
able to predict when and where they will hit land and how strong they might be, to help people prepare.
Storm surge from Hurricane IkeDamage caused by Hurricane Gustav
Image source: http://sos.noaa.gov/Education/forecast.html
Prediction the Path of a HurricanePrediction the Path of a Hurricane
We especially need to know the path of the hurricane to warn people who might be affected.
Tropical Storm Force Wind Speed probabilities, 120 hour, for Hurricane Katrina issued 5 PM Wednesday, August 24, 2005/NOAA
Click the image to go to a website showing any current hurricane warnings.
Track Forecast ConesTrack Forecast ConesA track forecast cone represents the probable track of a tropical cyclone (called a hurricane when they form in the Atlantic Ocean). These are changed as scientists get new data about the storm, because they want to be as accurate as possible.
Click the image to go an animation of the progression of forecast cones for the storm.
Historical PredictionsHistorical Predictions
Back in the old days, hurricane predictions were based entirely on ground observations. Before radio, telephones, and the Internet, imagine how hard it would be to share information, and warn people they might be in danger!
The great Galveston hurricane (in 1900) roared through the prosperous island city with winds in excess of 130 miles per hour and a 15-foot storm surge. When it was finally over, at least 3,500 homes and buildings were destroyed and more than 8,000 people were killed.
Image and caption source: http://celebrating200years.noaa.gov/magazine/galv_hurricane/Galveston19001.html
Developments in Prediction TechnologyDevelopments in Prediction Technology
Later, ships at sea were able to transmit information to shore via radio, and we developed radar and hurricane hunter aircraft (as in NASA’s HS3 mission) to give us more data to put into computer models to help with predictions.
Click on either image to go to a short video about NOAA’s advances in radar..
Click the image to go to an animation of the aircraft scanning a storm to monitor the formation of the eyewall.
Modern PredictionsModern Predictions
Even better, these days we have satellites that can watch the storm the entire time its active, greatly improving our ability to predict the path of a hurricane.
Hurricane Bonnie, August 1998: 5-Day Forecasts vs. Actual Storm Track.
Improved forecasts can save money ($600K to $1M per mile of coast evacuated) and lives by more precisely predicting where the hurricane eye will be located at landfall. Source. Dr. A. Hou, NASA DAO
Click the image to go to a video about forecasting hurricanes.
Satellite Views of HurricanesSatellite Views of Hurricanes
Satellites can show us the storm clouds as they move across the ocean, such as in this animation
of Hurricane Katrina
But what if we want to see more, such as how much rain is falling, or what is happening inside the storm? Satellites can help us with that, too.
Tracking Precipitation from SpaceTracking Precipitation from Space
• Satellites can provide a more complete picture of rain from space, allowing scientists to look at storms, rainfall totals, and changes throughout days to years
• The Tropical Rainfall Measuring Mission (TRMM) has been providing rainfall data since 1998 in the tropics and mid latitudes
• The Global Precipitation Measurement (GPM) Mission will extend observations of rain and snow up to the Arctic and Antarctic Circles
Instruments on TRMM - MicrowaveInstruments on TRMM - Microwave
NASA scientists are using the TRMM satellite to understand which parts of a hurricane produce rainfall and why, like this microwave image of a hurricane. The red and yellow indicate areas of heavier rainfall compared to the blue and green. This is especially useful over oceans, where we don’t have rain gauges.
Instruments on TRMM - RadarInstruments on TRMM - Radar
Using radar, TRMM can even see inside a storm! Revealing the 3-D structure of the hurricane can tell us a lot about what will happen next with the storm.
Hurricane Sandy on Oct. 28, two days prior to landfall
Click the image to go to an animation of the data.
Instruments on TRMMInstruments on TRMM
The upper image shows the same 3-D view into Hurricane Sandy (using radar) as the previous slide. The lower image is microwave data showing rainfall totals, also for Sandy. The more data we have to work with, the better chance we have of making good predictions!
Hot TowersHot Towers
Looking at what are called “hot towers” using radar has helped scientists develop insight into what causes hurricanes to intensify – the towers often occur before a storm gets stronger. Pretty important if you’re in the path of one!
TRMM Observations ofHurricane Bonnie (1998)
Towers in the TempestTowers in the Tempest
Share what you’ve learned!Share what you’ve learned!
Now that you know the basics about what causes a hurricane and how and why we try to predict them, create a news report or weather forecast (performed with a script or created as a comic strip), telling people about a hurricane that’s coming and how we know where it will hit and if it will intensify.
Images from Microsoft Office ClipArt
News Report or Comic StripNews Report or Comic Strip
Some ideas to consider including:•How is hurricane forecasting different now than it used to be?•Imagine being a weather forecaster in two different areas of the coast, one in the direct path of the hurricane and one only near it. What would be different about what you tell people about the storm?•How does our knowledge of a storm change as it gets closer? How might that change what you need to tell people?•Optional: How should people prepare for a hurricane?
Extension Activities
““Hurricane Survival” VideoHurricane Survival” Video
Comparing Improvements in PredicationsComparing Improvements in Predications
““TRMM at 15: The Reign of Rain” videoTRMM at 15: The Reign of Rain” video
““Hurricane Storm Surge” videoHurricane Storm Surge” video
Stay Connected!Stay Connected!
• Follow us on Twitter: @NASA_Rain
• “Like” us on Facebook: www.facebook.com/NASA.Rain
• Precipitation Education Website: pmm.nasa.gov/education