The Enforcer

https://www.netweather.tv/forum/topic/95065-model-output-discussion-is-the-beast-awakening/?do=findComment&comment=4412578 06z NAVGEM from the old thread. Note the low blows up and heads north, but crucially this is only after the colder uppers have been allowed to sink south first, so it is then a 'cold' low with cold uppers embedded in it rather than a pocket of mild air circulating around it. From what I had seen the full line up from 00z/06z was: ECM 00z (+Ens) + UKMO 00z + GEM 00z + CMA 00z + GFS Para 06z + ICON 06z + NAVGEM 06z vs GFS 06z (+Control & Ens) I haven't seen JMA 00z/06z or BOM (If it still exists) 0z/06z

A mild outlier, perhaps?

I don't think there has been a single GFS Op over the entire weekend that hasn't been on the late side of the mean in bringing the cold in.

Classic quote in the MOD thread emanating from the Midlands: "but even then nothing more than around 4inches." Oh, how the other half live.

Uncanny - there it is:

ECM coming out early to lead us up the garden path. 00z T+192: 12z T+180:

Example: 10th December 2017. Heavy rain all night. Turned to snow around 5-6am. Ground totally saturated. Gave about 5cm depth. In Abingdon. Most Hi-Res models had it as a total rain event even at T+0. At least matched level snow depths from March 2018.

With a 7-8C spread at D3, I think there needs to be another 5 days of this to get through to ensure that ECM hasn't simply 'forgotten' to model in an Icelandic Low.

Managed 3.5cm from this proper frontal band of snow, although much of that had gone by the end of Sunday even though the maximum was barely 2.5C. Signature gratefully updated nonetheless.

Covers most of this region now, updated within seconds of me copying the previous image:

Typical. Evidently they've been watching what potentially snowy precipitation does around here. But the above outbreak didn’t get the memo - light snow falling at -0.8C would give a dusting taking this to a Level 2 Winter.

Tortoise - always plodding towards us from T+384 and falling down the ECM trapdoor at T+120.

Day 4 of the Easterly - dry save a few spots of rain this morning. Maximum cleared 5C again. Current Minimum -0.5C. Heavier precipitation pushed much further westwards today, but of course only in the usual bands to the north and south of here courtesy of those stupid twiggy trough thingys:

Day 3 of the Easterly saw temps get over 5C again in spite of a biting wind and currently 1.5C. No precipitation has made it here. I don't know whether I'm more narked by it constantly failing between the M1 & M40 corridors or the fact that if any precipitation did have the temerity to make it a few miles further, it would be rain.

Red sky at night - shepherd’s delight; charts flipped in morning - sudden stratospheric warming.

Red sky at night - shepherd’s delight; charts flipped in morning - sudden stratospheric warming.

Based on the current pattern, I believe there are two probable outcomes: 1. 50% chance of shortwave mild sector (850s & dew points higher than presently forecast) which won't get picked up until T+0 turning the above to rain midlands southwards; 2. 50% chance of no mild sector but the shortwave fragments midlands southwards.

Day 2 of the Easterly saw temps get over 5C again in spite of a biting wind and currently 2.4C. Might have missed one brief shower this evening, which almost certainly fell as rain.

Day 1 of the Easterly ends with 3.5C at midnight after a maximum of approx 5.6C. All brief showers fell as rain.

I do. 2.9C and Rain. Crap again.

I found the latest BBC online forecast, uploaded 4 hours ago to be completely out of kilter with all the latest modelling for next week: 1. It starts by acknowledging that 'many' places in the north and west have lying snow already. 2. The phrase 'the weather is looking generally settled', does not compute with the graphics and indeed the current radar with showers piling in. 3. The statement 'showers mostly rain to lower levels' does not correlate with many reports of lying snow, let alone snow falling, away from hills and indeed in urban areas. 4. Temperatures reaching 4-6C. Even here we briefly barely scraped 4C today and many lowland places had much lower maxima, especially where the snow fell. 5. High Pressure dominant, well yes, but easterly breeze and showers are equally being driven by lower pressure to the south-east, causing the steep pressure gradient. 6. Constant references to it being largely dry and downplaying the gradual encroachment of colder air from the east, amount of showers and only a possibility of rain to snow on higher ground in heavier bursts. 7. Reference to turning more unsettled, but the only indicator of this on the summary graphic is rain next sunday in Fort William. It's almost as if they are still relying on forecast data from last week, are in denial or they think that the Abingdon 'must avoid snow at all costs microclimate' has expanded to cover all of the lowland UK.

Just imagine what the Newport IOW traffic bottleneck would be like when some snow is chucked into the mix.

Under the assumption that a genuinely cold easterly takes place next week as is currently forecast, if I could have one request it would be that these two trough thingys (which I have highlighted on the chart below) that I have just noticed, with horror, on two Fax charts for next Tuesday 00z & 12z, do not put in an appearance: This is because these features became established in almost almost identical positions in both the late November/early December 2010 and March 2018 easterlies, where for the duration of the said easterlies they persistently channelled all the showers into two unrelenting horizontal lines to the north and the south of here leaving a green gap in the middle (also highlighted on the chart above above), where no more than a dusting was ever permitted to accumulate. I believe even places much further east than here in Cambridgeshire and Norfolk suffered a similar fate for days on end, which quite honestly is laughable in a supposed snowy winter easterly.

Temp dropped 2C in under two hours to -0.4C, ready for a night of being dodged by any snow-producing precipitation.

Current temp 1.4C. A sixth near miss of the week means still not seen any falling snow. Honestly, the way any heavier precipitation that might contain a few flakes goes out of its way to avoid this area is laughable: Crap again.