Just reposting AWDs post from earlier, should you guys n gals not have seen it.
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Your right to a degree GTLTW, but remember that from now on, as the system rotates slowly WNW along an occlusion travelling east, colder air from the ENE will slowly undercut it.
This is the radar as of 12:20;
And this is the latest NAE forecast for midday (the 20mins differential shouldn't make too much difference);
All in all, so far not to disimiliar. Now the current 850hpa and Dewpoints for midday;
You can see that southernmost counties have slightly less cold air over them, with a weak feed of S/SW air causing th Dewpoints to rise slightly;
Therefore no surprise to hear of reports of rain in Devon, Dorset and Hampshire currently. However, fast forward 6 hours and the flow turns increasingly E/SE. As the low pressure in the channel starts drawing in a continental feed, reducing Dewpoints and 850hpa temps;
The low pressure in the channel not really moving anywhere, and the PPN around it is simply just pivoting west in an increasingly E/SE feed. At 18:00 the PPN is here;
Due to all the pivoting and rotating around the centre of the LP in the channel, its not really moved any great distance, just about reaching the M4/Bristol area by 18:00. It does however develop further due to the increasingly cold airmass mixing in with it. No surprise to see it turning to snow by this time then;
So the chance are, for Newbury, the main bulk of PPN would arrive after the cold air has dug down, therefore limiting any rainfall to drizzle beforehand. This would apply to most northern counties of our region.
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