PB22

So was it or wasn't it snowing?! You can either see it or you can't!!

Recent snow shower here. Now have a slight covering of snow after the showers in the last few hours.

Heavy snow falling here at the moment with near blizzard like conditions. First flurry occurred at around 9pm, with showers becoming frequent and heavier here.

Currently at 22:35 - Sunday 21st December 2003: Cloudy. Moderate Snow. Windy. Current temperature: 0.1C FALLING Wind: North/Northwesterly 28MPH Pressure: 1020mb RISING

Currently at 07:10 - Sunday 21st December: Cloudy. Recent rain. Windy. Current temperature: 4.1C RISING Wind: Westerly - 27 MPH Pressure: 997mb RISING

Please place any reports of hail, sleet or snow that you have today in this thread. All reports will be checked and verified, and any bogus reports will be removed. Thanks for your co-operation.

Another article! ____________________________________________________________ Understanding what the charts show - Precipitation: The colour shading is used to determine 6 hourly precipitation rates (of rain, snow etc.) in the period up to the time of the chart. There is a scale at the right hand side of chart - the deeper the blue colour, the more precipitation - purple/violet etc. means exceptional rainfall/snowfall accumulations (in mm) Paul Barber - December 2003

Understanding what the charts show - Mean Sea Level Pressure; Cloud (%) and 500-1000hPa thickness: The white lines are points of equal atmospheric pressure. The coloured lines are referring to thickness. This is a useful in finding warm and cold air in the lower 'half' of the troposphere (the surface to about 5.5km), where a large part of the 'weather' is to be found. Bulk movement of warm air (high values - 564DAM) and cold air (low values - 510DAM) can be followed by looping the fields. Look for areas where the thermal contrast is increasing as these are regions of potential major baroclinic development (i.e. low pressure development). It is advisable to avoid working out things like maximum temperatures, snow-level etc. from these charts. The monochrome shading is used to give cover forecasts. These give an output relating to the percentage of sky forecast to be covered with cloud. Hence 100% would be overcast, and 50% (equivalent to 4 oktas) predicts a half cloudy sky. This is useful for picking out where the frontal systems are and determining where they are most likely to be the most intense from the higher percentages given (scale on right hand side). *NOTE - This is for medium/high level cloud only. Low level cloud is not included.* Paul Barber - December 2003

Understanding what the charts show - 850hPa and Temperature: The white lines are contours of 850hPa isobaric surface. The black lines are isotherms of 850hPa temperatures (deg C). The colour shading is used to determine the 850hPa temperatures. 850hPa level is around 1.5km high, usually above the atmospheric boundary layer. Therefore there is no diurnal temperature variation, and the underlying surface such as a cool sea won't affect it's temperature. This is why the 850hpa temperature is used to distinguish air masses and thus to locate cold and warm fronts. Generally, the 850hPa temperature can be related to the 2m temperature by adding around 10 degrees, and use it instead of surface maximum temperature. There is a scale on the right hand side of the chart. However, this only works at low altitudes, and only when the sun is heating the ground; not at the sea or near to the coast. It doesn't apply at night-time either, and often not in the winter. Paul Barber - December 2003

Understanding what the charts show - Mean Sea Level Pressure and the 500hPa height and temperature: The white lines are used to show points of equal atmospheric pressure. On one side of the isobar pressure will be smaller than the isobar value, whilst on the other side its greater. Wind follows roughly the direction of the isobars so that if you walk along an isobar (not literally!) and the wind is blowing onto the back of your neck, the lower pressure is at your left hand side (in the Northern Hemisphere). The dark grey dashed lines gives the forecast temperature at 500hPa height. The colour shading is used to determine the 500hPa height (there is a key on the right hand side of the chart). The level of 500 hPa is roughly dividing the mass of the atmosphere in two. It lies near 5km, and its height is normally analysed at intervals of 40 or 80m, corresponding to MSLP isobars at intervals of 5 or 10 hPa. Paul Barber - December 2003

Morning all Currently at 10:35am - Sunday 02nd November 2003: Cloudy. Wet. Moderate to heavy rain. Windy. Current temperature: 10.2C STEADY Wind: Southerly 24MPH Pressure: 991mb FALLING

Currently at 16:10 - Wednesday 29th October 2003: Cloudy. Misty. Wet - Moderate Rain Cold. Current temperature: 5.9C FALLING Wind: Westerly 10MPH Pressure: 991mb FALLING

Currently at 19:10: Cloudy. Cold. Current temperature: 5.2C RISING Wind: Southwesterly 5MPH Pressure: 1009mb FALLING

Currently at 19:30: Fine. Clear. Cold. Current temperature: 3.7C FALLING Wind: Northwesterly 4MPH Pressure: 1019mb FALLING

Currently at 18:25: Clear. Cold. Dry. Current temperature: 4.2C FALLING Wind: Northwest 3MPH Pressure: 1020mb FALLING

18C now! :shock:

Afternoon all. Not even mid afternoon and already temperatures are dropping sharply here! Currently at 14:45: Sunny spells. Cool. Current temperature: 8.9C FALLING Maximum today: 11.7C Wind: Northwest 4MPH Pressure: 1021mb STEADY

Currently at 23:15: Dry. Clear spells. Chilly. Current temperature: 5.1C RISING Wind: Northerly 4MPH Pressure: 1018mb RISING

Currently at 20:45: Clear. Cold. Current temperature: 4.9C FALLING Wind: Northerly 7MPH Pressure: 1017mb RISING Rainfall today: 2.7mm

Currently at 19:45: Clear. Cold. Recent Light Showers Current temperature: 5.7C FALLING Maximum today: 10.8C Wind: Northerly 7MPH Pressure: 1017mb RISING

Currently at 10:55am: Sunny spells. Cool. Current temperature: 6.0C RISING Wind: Northerly 12MPH Pressure: 1015mb RISING

Morning all. Currently at 09:45am: Sunny spells. Patchy cloud. Cool. Current temperature: 5.3C RISING Minimum last night: 4.8C Wind: Northerly 8MPH Pressure: 1014mb RISING

Showers have arrived here now. Currently at 22:40: Cloudy. Rain. Cold. Current temperature: 6.2C FALLING Wind: West/Northwest 11MPH Pressure: 1014mb FALLING

Currently at 20:45: Cloudy. Breezy. Less cold. Current temperature: 7.4C STEADY Wind: West/Northwest 14MPH Pressure: 1015mb FALLING

Afternoon all! Sunshine turned more hazy now as cloud builds ahead of the trough moving south across the UK. Currently at 12:25pm: Hazy sunshine. Cool. Breezy. Current temperature: 7.2C RISING Wind: Westerly 13MPH Pressure: 1020mb FALLING