Briefing Guidelines - Metr 170 A

 

These guidelines are designed to give you a framework from which you can develop a weather briefing. When giving your briefing it is very important to use established terminology for the situation or phenomenon you are describing, please ask for help. A briefing starts with study and preparation. You can't give a good weather briefing if you don't understand the weather situation, and you can't understand the weather situation without thorough analysis and study. It is quite common to talk about less than 1/4 of what you study and prepare for in your briefing. All items below should be looked at before you prepare your briefing. Items where it says "optional" represent the minimum material to be presented. Other items where it says "examine" should be presented if they are pertinent, add quality and breadth to the briefing, AND you have something relevant to say about them. When referring to or pointing to places on the map, use the correct geographic references, see map1 and map2

 

(Note: you should always have read at least the local Forecast Discussion, and maybe the surrounding ones as well) 

 (Note: if this is the first day of a city, then show climo numbers and topography map)

A. Big picture: (2 minutes)

1) Discuss large scale (hemispheric) analyses and locate major troughs, ridges, jet streams, and short waves. 

       a) discuss 12z GFS NA 300 mb heights and isotachs (Troughs, ridges, jet stream)

     b) discuss 12z GFS NA 500 mb heights and vort. (Troughs, ridges, shortwaves...do not mention vorticity,flow type - zonal/meridional)

2) Discuss large scale satellite imagery as it relates to large weather features in the forecast region.  (Usually IR, GARP)

3) Show current large scale surface analysis. (Focus mostly on surface pressure patterns and fronts relevant to our area.) Other analyses can be found here. And here.
  

B. Current local weather analysis: (2 minutes)

1) Discuss the current and previous obs. (Station history, how did we get here?) (Also show surface plot SJSU)

2) Discuss local satellite imagery (GARP 1KM Vis, zoomed)

3) Optional - Examine local radar if precipitation is occurring in our region.

 

C. Forecasting: (10 minutes)

1) Discuss model forecasts for your location, use 12Z NAM 212 East/West or GFS East/West and use the "forecast funnel" unless otherwise indicated:

    a) 300 mb isotachs (RH if necessary) (jet position and movement, impact on our area, entrance - exit regions)

    b) 500 mb heights and vorticity. (RH if necessary) (shorwave trough and ridge movement, vorticity advections - DPVA, DNVA)

    c) 700 mb omega from GFS East. (700 RH if necessary) (large scale synoptic lift, what is causing it?)

    d) 850 (or 925mb temps) (RH if necessary) (temperature advections - warm and cold, temp changes day to day)

    e) Surface temps/precip (From NAM 215 and GFS precip for comparison if necessary) (temp, surface pressure pattern, winds)

    f) identify significant NAM GFS model differences if they exist. (flip back and forth or make overlay)

2) Identify the main forecast problem or problems.(this can be done in 1 above, you may consider referencing the forecast discussion)

3) Discuss model soundings, step through period and discuss progression of weather and pertinent sounding features. (veering and backing, inversions, fronts, moisture layers)

4) Optional - Examine significant interpolated model numbers if helpful (TAMU)

5) Discuss the GFS, NAM (AVN, ETA) MOS forecasts for your location.

6 ) Make a forecast, enter forecast in computer...yes, during your briefing!!

7) Answer questions

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