Transcript Penn State Weather Camps

Penn State Weather
Camps
Basic Weather Forecasting Guidelines
Basic Forecast Guidelines
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Climatology Forecast = averages for today
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Persistence Forecast = yesterday’s values
Basic Forecast Guidelines
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Climatology – Persistence – Modified Persistence
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What causes temp to change?
◦ Cloud cover:
 Day Vs. Night
◦ Precipitation:
 When it rains T’s tend to be higher/lower? Why?
◦ Wind and Fronts:
 Direction
◦ N vs. S
 Speed
◦ Day Vs. Night
Basic Forecast Guidelines
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What causes rain?
◦ Need clouds!
 Will any ole cloud do?
◦ Moisture supply
 Bodies of H20 – Moisture content of air (Td)
◦ Upward motion:
 How affect clouds/precip.?
 Mechanisms for “lift”
◦ Fronts – Topography – Low Pressure – Jet stream dist.
◦ Intability (convection):
 Warm down low … cold up high!
Basic Forecast Guidelines
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Climatology – Persistence – Modified Persistence
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Extrapolation/trend Forecast = Look upstream to
see what the wind’s bringing in !
◦ Satellite IR - Satellite VIS - Radar - sfc. map 1 - sfc. map 2
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Thunderstorms/Moist Convection
◦ Triggers ?
◦ Fuel
 LI
 Cape
Basic Forecast Guidelines
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The “Models”
◦ Simulate future state of atmosphere
◦ Higher resolution / lower resolution
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The “Models”
◦ Lower Res. (GFS)
◦ Higher Res. (NAM)
◦ Higher Res. (HRRR)
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Clouds Forecasting …
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◦
◦
◦
Soundings
Cloud forecasting I
Cloud forecasting II – NAM
Cloud forecasting II – HRRR
 Your
competition !!!
◦ The National Weather Service
◦ The Weather Channel
◦ Accuweather
◦ The guy or gal to your left and right 