Penn State Weather Camps Basic Weather Forecasting Guidelines Sat I Sat I - NWS - Radar - RadarNWSRadar sfc. map 1 sfc. map 1 - sfc. map 2 – sfc map 3sfc. map 2sfc map 3

Know what to expect! = Climo.

Basic Forecast Guidelines Climatology Forecast = averages for today Persistence Forecast = yesterday’s valuesyesterday’s values

Basic Forecast Guidelines Extrapolation = Look upstream to see what’s coming! ◦Sat IR - Sat II - Sat VIS - Radar - sfc. map 1 - sfc. map 2 – sfc map 3Sat IR Sat II Sat VIS Radarsfc. map 1 sfc. map 2sfc map 3

Basic Forecast Guidelines Weather Models … What’s under the hood? NAM GFS ECMWF CMC Mathematical Equations …. “Perfectly express the physical processes of the atmosphere”

Basic Forecast Guidelines Weather Models … What do we “feed” them? Run 2 times a day (12z/00z) NAM GFS ECMWF CMC

Basic Forecast Guidelines Deterministic Forecast ◦precise/exact/no uncertainty provided Non-Deterministic Forecast ◦uncertainty provided via a range or probability ◦High: 82 ◦Cloud: 8 ◦Rain: Yes Deterministic or Non?