Just before 10am on 13th May 2014 and the first lightning strike (sferic) has shown up on the Netweather radar this morning.
Trying to describe in a forecast where the showers will be, is often tricky for a forecaster and frustrating for the reader. On a showery day, 'Nowcasting' is used a lot especially at sporting events, such as the golf and tennis.
Thunderstorms are the showers of particular interest but this nowcasting idea can be used for smaller showers which may just spoil your own evening BBQ.
Towering Cumulus TCU and Cumulonimbus CBs and Thunderstorms TS are steered by winds at 700hPa, higher up in the atmosphere than the surface winds usually seen. These steering wind charts are available on Netweather. Here's todays from 10am. You can see a NW wind. So showers will be pushed southeastwards.
The first lightning strike was near St Helen's in Merseyside and there are more forecast today.
Looking at 0815 and 0945 from the radar you see how 2 shower cells have moved and developed (brighter colours showing on the pixels) the orange one having turned thundery. Bit of ommph from the warmth in the sun and up the cloud goes.
You can use the wind speed to calculate how long the shower will take to reach you, impress your friends, be a party pooper.
