1. ATOC 6700 Weather Forecasting Discussion

2. Student Introductions Tell us: – Your name – Your year in ATOC graduate program – The topic of your research

3. Course Goals Apply theoretical concepts from ATOC core classes (esp. ATOC 5050 and 5060) to real-world mid-latitude weather Attempt to develop a cohesive “story” to relate atmospheric processes to the weather observed at specific locations You will have incomplete data as you develop your story – this is the same challenge you will face in your research

4. Course Approach Weekly weather discussion led by students – What are the key weather elements that will influence the weather at our forecast cities? – How will these weather elements impact the sensible weather at our forecast cities for the next several days? Forecasting contest Critique past forecasts to learn sources of forecast errors – Weekly forecast analysis write-up

5. How will we achieve these goals? Weekly weather discussion (handout)handout – Forecast review – Discussion of past week’s significant weather (optional) – Forecast discussion Forecasting contest – Forecast daily high and low temperature – Forecast daily precipitation category – Forecasts for 6 to 54 hours in the future (day 1 and 2) – Forecast for Denver, CO and Chicago, IL – Forecasting contest entry page Forecasting contest entry page Written forecast analysis (handout)handout – Analysis of your forecast for one forecast city Key weather elements you expected to impact the city Impact of these weather elements on the sensible weather in the forecast city – What did you forecast and what verified? – What aspects of your forecast were correct / incorrect?

6. ATOC 6700 Expectations You should plan on: – Spending at least 1 hour per week preparing your forecasts – Spending 1 to 2 hours per week assessing your forecast and preparing your written forecast analysis – Contributing to the weekly weather discussions – Leading one weekly weather discussion during the semester, which will require several hours preparation

7. Weather Forecasting Review ATOC 6700 28 August 2013

8. Key Weather Elements Troughs / ridges – PVA / NVA Jet stream Fronts Low and high pressure centers

16. Key Weather Elements Troughs / ridges – PVA / NVA Jet stream Fronts Low and high pressure centers

17. Why are these important for forecasting the weather? Rising / sinking motion – Cloud and precipitation development Divergence / convergence – Forces vertical motion – Surface pressure Temperature advection / air mass change Wind shift (frontal) Rising motion (frontal)

18. Forecasting Local Weather Temperature – Air mass temperature / CAA / WAA – Clouds – day vs. night – Winds – day vs. night – Time of year – Recent precipitation / soil moisture / snow cover – Local effects on temperature (topography) – Humidity / fog impacts on temperature

19. Forecasting Local Weather Cloud cover – Moisture – Rising or sinking motion – Frontal clouds – Convective clouds

20. Forecasting Local Weather Wind – Near surface wind and SLP Or look at 850 or 700 mb maps for indication of surface winds at DEN – Upslope vs. downslope winds – Topographic effects on winds (wind storms)

21. Forecasting Local Weather Precipitation – Moisture availability – Dynamic forcing Troughs / ridges / PVA / NVA Jet stream Fronts Low pressure center – Local forcing Topography

22. Weather Terms Refresher A weather term primer is available on the class web page (at the bottom of the Weather Links page)weather term primer

23. Weather Products Available Online ATOC 6700 web page NCAR Real-time Weather Data University of Wyoming Weather Web Plymouth State Weather Center NCEP Models Forecast Model Animator National Weather Service web pages Week in Review – Observations Week in Review – Guidance Review

24. Observational Weather Products Surface data – Maps (NCAR Real-time Weather Data, NWS North American Surface Analysis )NCAR Real-time Weather Data NWS North American Surface Analysis – Text list of time series (Plymouth State)Plymouth State – Meteograms (Plymouth State)Plymouth State Upper air maps (University of Wyoming)University of Wyoming – What levels are of interest for forecasting? – What can we learn from each upper air map? Soundings (University of Wyoming)University of Wyoming

25. Observational Weather Products Satellite images (NCAR Real-time Weather Data)NCAR Real-time Weather Data Radar (NCAR Real-time Weather Data)NCAR Real-time Weather Data Severe weather – Thunderstorms (Storm Prediction Center)Storm Prediction Center – Hurricanes (National Hurricane Center)National Hurricane Center

26. NWP Products Model forecast maps – Which maps are of interest for forecasting? – NCEP Models NCEP Models – Forecast Model Animator Forecast Model Animator – NCAR Real-time Weather Data NCAR Real-time Weather Data – University of Wyoming University of Wyoming Model output statistics (MOS) – Ex. DEN NAM MOSDEN NAM MOS – Reading MOS products Reading MOS products

27. NWS Products Zone Forecast – DEN DEN – ORD ORD Grid Forecast – DEN DEN – ORD ORD Forecast Discussion – DEN DEN – ORD ORD