Storm Forecast - From 21 June 2017
UK & IrelandFull Charts For UK & Ireland
A large amount of model divergence and uncertainty regarding the storm potential today across the UK. One of the problems comes from the GFS and the overnight dew point temperatures across much of Central and Southern England which are progged much higher than observations from several stations which we have looked at from this mornings soundings.
That said, the ECMWF was the only model to correctly identify the upper level storms across Northern England this morning and this is the model which we will give weighting to for much of today.
Later this afternoon, daytime heating will continue to develop across much of England and Wales. Low level moisture will continue to feed in across Northern England where upper level shear profiles show considerable hodograph curvature.
The ECMWF brings in the short wave trough a little later than other models, perhaps a little too late to take advantage of the daytime maxima which other models show as coinciding with the timing of the trough.
Regardless of the timing, all models indicate the upper level atmosphere conducive for well organised thunderstorms across Northern and Central England later this afternoon. A risk too for moderate to large hail as well as tornado development, the GFS shows this risk up well too :-
Factors which will reduce this risk include :-
- Upper level high cloud reducing the maximum temperatures today
- The timing of the short wave trough
- Whether the cap can be broken before or after the maxima today.
So, potential for some very nasty storms across Northern and Central England this afternoon, but as ever the situation is highly uncertain and meteorologists are advised to use nowcasting from midday.
METEOROLOGIST : MARSH |