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Lecture 4. Weather Maps and Models Chapters 3 and 4. Homework. Due Friday, September 22, 2006 (add to previous homework) Ch 4 TYU 2,6,9,12,14,17,18,23,25 TYPSS #2. Meteograms. Display state variables graphically over a period of time. AOS rooftop site: http://rig.ssec.wisc.edu/.
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Lecture 4 Weather Maps and Models Chapters 3 and 4
Homework • Due Friday, September 22, 2006 (add to previous homework) • Ch 4 TYU 2,6,9,12,14,17,18,23,25 TYPSS #2
Meteograms • Display state variables graphically over a period of time. • AOS rooftop site: http://rig.ssec.wisc.edu/
Surface Maps Station Plots Dew point analysis MSLP analysis(mean sea level pressure) Temperature analysis
Upper Air Station Plot Upper air charts http://www.aos.wisc.edu/weatherdata
Upper Air chart(Constant pressure surface) Upper air charts http://www.aos.wisc.edu/weatherdata
Weather Models • Mathematical equations describe how: • Air accelerates or decelerates based on Newton’s Laws • Mass of air and its properties move from one position to another while conserving properties of mass and energy • Mass of water vapor is moved and transformed to rain and snow • Air is heated or cooling by condensation, radiation • These differential equations are integrated forward in time by solving them numerically on a grid
Two Basic types of Models • Finite Difference Model • Solved on a grid • Taylor series approximations to continuous equations • Spectral Model • Analysis of variables on a grid in real space is transformed to a grid in wave space grid using a Fourier transform • Equations moved forward in wave space analytically • Variables transformed back to real space
Vertical Grid • Vertical grid may be : • Height coordinate • Pressure coordinate • Sigma or terrain following coordinate
Map Projection • Various map projections are used to take into account the curved Earth surface. For instance: • Mercator projection • Polar Stereographic Grid • Lambert Conformal • Spherical Grid
Look at AOS Web Page • Real Time analysis and Prediction available on the Web: Weather Maps (Current and Forecast Maps): http://www.aos.wisc.edu/weather/index.htm (Maps drawn by UW AOS Department) http://cup.aos.wisc.edu (Tripoli’s NMS Model output) http://www.nws.noaa.gov/outlook_tab.php (National Weather Service Maps) http://weather.unisys.com/ (Unisys (Purdue) Maps….traditional leader in Internet map technology) http://www.meteo.psu.edu/%7Egadomski/ewall.html (Penn State Electronic Maps) http://www.atmos.albany.edu/weather/difax.html (NWS difax maps from SUNY Albany) http://www.rap.ucar.edu/weather/ (National Center for Atmospheric Research Weather) http://hdrweather.com/f2p2/default.htm (Colorado weather by Henz)