Step 1: analysis 500 hPa •Flow patterns Check and mark main trough and ridge axes and try to determine the movement. Check if they are confluent or diffluent. Check the curvature, look especially for any changes in the future or developments upstream which may affect the curvature. Mark possible jets and their associated development zones (C or A). •Isothermal patterns Check major zones of CAA and WAA and locations of cold pools. Look if they coincide with cyclonic curvature which is a first indication of fronts or troughs. Step 2: analysis 700 hPa •Humidity fields Compare the analysis of 500 hPa with the 700 hPa humidity chart and try to define the position of active fronts and/or troughs. Try to detect were apparent frontal zones on the 500 hPa map do not coincide with humidity fields on 700 hPa which might indicate low level or upper level features. Extensions in the humidity pattern indicate weakening fronts or wave formations. Dry zones indicate strong subsidence. Step 3: analysis 850 hPa •Vertical structure -CAA 500 hPa coincide with CAA 850 hPa: pre-running front is well structured with most likely active precipitation. -CAA 500 hPa coincide with WAA 850 hPa: heavy instability with serious risk for heavy showers/thunderstorms, especially in spring or summer. -WAA 500 hPa coincide with CAA 850 hPa: instability mainly in lower levels but decreasing by subsidence or prefrontal heating from aloft. -WAA 500 hPa coincide with WAA 850 hPa: indication of a strengthening (upper) high with most likely strong subsidence at all levels. •Front/trough -CAA 500 hPa coincide CAA 850 hPa: active front. -CAA 500 hPa: trough. -CAA 850 hPa: front, in general weakening and only existing in lower levels. Step 4: analysis additional parameters •MSLP (Mean Sea Level Pressure) Detailed info like position of surface high and lows, kinks in the isobars indicate exact frontal position, etc. •Mesoscale output Detailed info with regards to clouds (type, amount), precipitation (type, amount), wind (direction, speed), temperatures, etc. •Humidity charts 500, 850, 925 hPa Indicate if fronts are surface features or not. •Upper winds 200, 300 hPa Detailed info on position of jetstream and jetstreaks. •Vertical motion and instability indices Identification active fronts or active parts of upper troughs. •Theta W* or potential equivalent temperatures 850 hPa & thickness between different levels Identification different air masses. * (Theta W = wet bulb potential temperature) •Soundings Identification of position of humidity levels + stability of atmosphere + inversions, etc. •Satellite pictures, radar, lightning maps Verification of exact position of fronts, showers, thunderstorms. •Surface observations Verifications of various weather phenomena. Step 5: finalizing analysis •All relevant info for the forecast is put on the 500 hPa map. This map is always the starting point for a forecast in text form