The Enforcer

Spot the difference: Current Forecast: Actual:

If anyone wants confirmation of short-term forecast volatility, then look no further than the latest Fax charts. T+96 for Tuesday shows a developing Low over the Bay of Biscay: T+120 for Wednesday only 24 hours later - BANG - and the Low is gone:

Good spot. Even if the mid-long term northern hemispheric pattern doesn't play out as many have been anticipating, these localised troughs that seem virtually impossible to model (e.g. heavy lowland snow in the South this Tuesday afternoon) are on a mission to stick two fingers up at the eternal "winter is over brigade". Who knows what tonight's feature will do? Watch that radar, boys.

T+96: The air source has changed from North-Atlantic to Scandinavia to Arctic. This looks like a wintery Jet trajectory to me. I wouldn't mind if this NW-SE pattern kept repeating over the next few weeks.

Meanwhile, who wants to join us in time for Sunday lunch? T+144: T+120:T+96: ?

I have come out of reverse-hibernation too soon. It is rather damning that the potential snow event that was identified from a week away, now within 48 hours is shown as 'rain only' when the following factors apply: 1/ 850's at least -7C (for Oxfordshire) 2/ below average 2m temperatures ahead of the cold front 3/ core period of winter (how many times does one read "if only this had been in January"?) 4/ front crossing overnight 5/ active front - some heavy precipitation I have this weird hunch that the conditions look more favourable for this than the 10th December 2017 rain to snow event (unforecasted for here by at least half of the hi-res models even at T+6), which gave as much snow here as the entire March easterly.

Visits to North Norfolk are always good, but it is a bit like the land that weather forecasting forgot. No rain forecast at any point this week and still only '10%' on the bbc nowcast yet it has been belting it down in West Runton since it went dark. Maybe they should stick to this method of forecasting:

Weird that it has cleared from eastern counties, but remains inland.

That might explain the aforementioned difference in the precipitation pattern - an upper warm front in the south east corner.

What intrigues me is the marked difference in how north of The Wash and Thames estuary convergence lines look on the radar. The former has produced lines of showers with bright echoes denoting heavier bursts. The latter is a single wider area extending as far west as the showers further north, but consists of mostly light snowfall with heavier elements almost exclusively east of London. This is very similar to the precipitation pattern that developed a few weeks ago. Is there a reason for this difference?

An existing rather than a developing front this time, but has already reached the west coast by 12pm Saturday, when it does weaken. The snow warning for late Friday/early Saturday was eastern coastal counties only, so I'd expect this to get extended further westwards on the basis of these charts and what you are saying about the ECM output.

Appreciate the clarification. A promising development for those who like snow-bearing cold fronts, although met office snow warnings just out ignore this feature with snow warnings late Friday/early Saturday and during Sunday, but nothing when the front is there. Must indicate very low confidence.

Hi, you describe the cold front as a weakening feature, but I thought that a cold front with dots rather than lines between the triangles was a developing feature? Cheers, TE

Ended up with a maximum total of around 5cm once levelled off built up slowly over a few days of mostly light snowfalls with the odd heavier spell. Now melting at 2C. Similar amount to what we had on December 10th.

January 2010, Central Southern England.