Area forecast in a map format issued for Poland’s territory from the ground level to FL100 and to FL150 in mountain regions (SFC-700 hPa), low level (low-level SIGWX) – SWC is issued by forecasters in Central Aeronautical Forecasting Office-Meteorological Watch Office for general aviation. SWC is a general weather forecast and contains information on significant weather phenomena for aviation.
SWC forecast availability and validity (time given in UTC)
06.00 ( 03-09 )
12.00 ( 09-15 )
18.00 ( 15- 21 )
00.00 ( 21-03 )
SFC-FL 100 including the following constant elements:
Height of isotherm 0° written in frames: for example 080 -> 8000 ft -> 2400 m, SFC -> temperature below 0° from the ground level, n.SFC -> -> temperature above 0° near the ground level falling below 0° at the ground level, XXX -> temperature above 0° in the whole layer from SFC to 700hPa, 020/080 -> the height of isotherm 0° 2000ft and 8000ft, in the layer 2000-8000 ft the temperature is above 0°.
Wind speed and direction on FL050 given in knots. The location of pressure centres is given with its value.
Information on clouds:includes cloud amounts (from FEW to OVC), type of clouds (symbol, for example AS, CU), location of lower and upper boundary given in hundreds of feet above the mean sea level. If a cloud top reaches above FL100, then it is reported as XXX. If the cloud base is above 1500 m and no clouds CB and TCU occur then the abbreviation NSC is used. If the sky condition is clear then the abbreviation SKC is used.
Some additional elements may occur: fronts – type and its location near the ground, wind gustsGUSTS given in KT (knots) with the speed more than 30 kt.
Abbreviations used for reporting only TCU and CB clouds: ISOL, OCNL, ENBD, FRQ: ISOL CB / TCU shall be considered isolated if they consist of individual features which affect, or are forecast to affect, an area with a maximum spatial coverage less than 50 per cent of the area concerned at a fixed time or during the period of validity OCNL CB / TCU shall be considered occasional if they consist of well-separated features which affect, or are forecast to affect, an area with a maximum spatial coverage between 50 and 75 per cent of the area concerned at a fixed time or during the period of validity FRQ CB/TCU shall be considered frequent if there is little or no separation between adjacent thunderstorms with a maximum spatial coverage greater than 75 per cent of the area affected, or forecast to be affected by the phenomenon at a fixed time or during the period of validity EMBD CB/TCU shall be considered embedded if they are embedded within cloud layers and cannot be readily seen due to darkness
Visibility given in kilometres and metres, for example:
10 KM 3-5 KM BR 1500-3000 M DZ 300-500 M FG
Phenomena - given in accordance with METAR code and placed next to visibility (if they occur).
Separated and described areas of different weather types and clouds coverage constitute so called shell line. Inside this line there is an area with worse weather conditions. Sometimes additional terms are used in order to specify its localization for example COT + MAR, MON, etc. Broken line embraces the zone with significant changes of a single weather element. All altitudes are given in hundreds of feet above mean seal level.
Dictionary of SWC abbreviations.
above ground level
above mean sea level
at the coast
tornado or waterspout
GUSTS UP TO... KT
variations from mean wind speed (gusts)
hundreds of feet- altitude indicator
heavy (to indicate the intensity of weather phenomena)
kilometres (to indicate visibility)
layer or layered
metres (to indicate visibility)
moderate (to indicate the intensity of weather phenomena)
nil significant clouds
near the ground
partly covered area for example with clouds or fog
rain with snow
severe (to indicate the intensity of icing and turbulence)