Transcript Feb 25th PowerPoint

Weather and Water
Monday February 25th
Session Topics
• Hurricanes
• Weather Fundamentals
• A review of Cloud & Weather
observations from 2/17 -2/15
• Observations vs. predictions;
a few Internet sites to gather data
to make short term forecasts
White
White
Hurricanes (Atmosphere/Ocean storms)
A hurricane is a tropical cyclone that occurs in the Atlantic Ocean.
What type of pressure system is a hurricane?
What is the relationship between hurricane
intensity and sea surface temperatures?
http://cimss.ssec.wisc.edu/wxfest/explore.html
Can you list two big picture ideas from the
SMI Weather and Water course related
to hurricane development and movement?
Hurricanes (Atmosphere/Ocean storms)
Hurricanes stand out on satellite images due to their circular cloud
patterns and, in stronger storms, a nearly clear eye at the center.
Immediately surrounding the eye is a narrow, circular, rotating
region of intense thunderstorms called the eye wall. Winds in the
eye wall thrust up as much as a million tons of air every second.
Hurricane Iris (2001)
Hurricanes
Ingredients for a Hurricane
1) Warm ocean waters about 80°F ( 27°C) or warmer.
2) Lack of vertical wind sheer that might slow or detour rising air drafts.
3) Some sort of pre-existing weather disturbance
Hurricanes are essentially large weather engines fueled by the latent heat
of water generated when ocean water enters the atmosphere as vapor.
The energy required for this evaporation process comes from the Sun,
and this energy is lying in wait -latent- ready to be released again when
the vapor is condensed into liquid.
Hurricanes
POES and GOES monitor hurricanes
Visible image from a polar orbiting satellite
showing Hurricane Isabel making landfall
Infrared images from a geostationary satellite
Hurricanes
Hurricane Felix, September 2007
Morning Clouds & Afternoon weather
DATE
MORNING CLOUDS
AFTERNOON WEATHER
Sunday
2/17
Monday
2/18
Tuesday
2/19
Wednesday
2/20
Thursday
2/21
Friday
2/22
Saturday
2/23
Sunday
2/24
Monday
2/25
http://www.weather.gov/data/obhistory/KMSN.html
Weather Fundamentals – Fronts
Fronts
The transition zone or boundary between two distinct air masses.
AIRMASS PROPERTIES AND SOURCE REGIONS
CO
LD
COLD
& DRY
&M
OIS
T
M
D&
L
CO
WARM &
MOIST
WARM
& DRY
WARM &
MOIST
T
OIS
Weather Fundamentals – Highs and Lows
The divergence of air at the surface out of high
pressure areas induces sinking air above,
causing clear skies and dry conditions.
The convergence of air into Lows forces air
to rise at the center, leading to moist, cloudy
conditions. This is why clear skies on satellite
images typically indicate high pressure
and clouds indicate areas of low pressure.
Weather Fundamentals – Station Weather Plots
Internet sites for short term Weather Forecasting
12Z analysis for Continental United States
http://www.ametsoc.org/amsedu/dstreme/images/sfc_map_12.gif
Wisconsin surface Map
http://www.crh.noaa.gov/images/grb/maps/wi_sfc.gif
Satellite Imagery and animations
IR http://www.ssec.wisc.edu/data/east/animation/goeseastir.html
VIS http://www.ssec.wisc.edu/data/east/animation/goeseastvis.html
Daily Forecast Map
http://www.hpc.ncep.noaa.gov/noaa/noaa