Nick F

Not entirely convinced of the increasing trend of the Atlantic push the models have started over recent runs, the EC det. in particular seems to be taking this scenario by the horns by not retrograding the block as far before it retreats back into NE Europe and Russia to allow Atlantic troughing to take over. Handling by models of blocks like these still not to be treated with too much confidence IMO beyond day 6 or 7. The 12z EPS det for London looks on the mild side for London at least: more runs needed to be confident of where the block positions in medium range, whole N Hemisphere 500mb seems to be retrograding upstream too, expect some wobbles, but deep cold pot of gold to the NE out of reach for now.

Unseasonably mild next few days, but turning colder from the east into next week, but will there be snow? View the full blog here

Think we need to wait until the block potentially drifts over Iceland/east Greenland to then tap in to deep cold direct from the NE, the cold pool edging west over continental Europe under the block by then over Scandi early next week will probably be too 'mixed out' at low to mid-levels by the time it reaches NW Europe to bring anything more than a chilly breeze and low cloud with drizzle to eastern coasts.

November 2010 redux from a synoptic POV looking at the 00z EC and comparing it with the synoptic evolution 8 years ago mid-late November. EC thrusts west a cold pool across Baltic, Poland, Denmark and Germany pretty early on (early next week) compared to other models. Like Nick L says, not cold enough for snow for most, but certainly chilly/raw feel in the easterly. By day 10 certainly the potential for much deeper cold to drop down from the NE, as the high over Scandi retrogrades over Iceland and Greenland, aided by the trop PV over Canada also retrograding toward Siberia. But too far away to have confidence in this for now. Interesting in the days ahead to see how the models handle the HL block and the deep cold trying to sneak round the block to the NE over Scandi and NW Russia.

Storm & Convective Forecast Issued 2018-08-06 21:33:50 Valid: 07/08/2018 00z to 08/08/2018 00z THUNDERSTORM OUTLOOK - TUESDAY 7TH AUGUST 2018 Synopsis North Atlantic upper trough will begin to amplify S and SE across the far west of Britain during Tuesday, with a strengthening upper flow across the UK – as SWly jet stream shifts S and E across the UK. Ahead of the jet streak, a weak surface cold front will progress slowly east, to lie North York Moors - West Sussex by 00z Weds. A very hot, humid and increasingly unstable airmass ahead of the cold front across SE England and East Anglia is forecast to destabilise and produce thunderstorms in the evening here before the front clears through and introduces cooler and more stable air. … SE ENGLAND and E ANGLIA … Surface-based CAPE will build up through the day due to surface heating of humid plume in conjunction with lapse rates steepening in association with advection north of EML (elevated mixed layer) aloft. However, this surface instability is likely to remain capped. However, a shortwave in the strengthening flow aloft will move NE from Bay of Biscay area in the morning crossing NW France in the afternoon. The increased lift by the shortwave along NW edge of hot and humid plume over France and SE UK combined with increasing mid-level instability as dry air intrusion punches NE overlapping plume, is forecast by many models to break out thunderstorms across Brittany and Normandy by early evening, before spreading / expanding NE across SE England then East Anglia through the evening. Thunderstorms are likely to be elevated, though 40-50 knots of 0-6km shear forecast will allow storm organisation into clusters, perhaps even an MCS passing over parts of Kent and eastern E Anglia, so there is potential for strong storms that may bring locally intense downpours leading to flash-flooding, isolated hail, strong wind gusts and frequent cloud-to-ground lightning. These storms should clear away NE into the North Sea after midnight. Issued by: Nick Finnis

Southern North Sea temperatures are a good 10C warmer now than early March this year! Now Early March 2018

It’s not that often you see models in good agreement over placement of high pressure in the medium range, but looks like good news for those who don’t like mild and wet autumn weather such as we’ve endured in recent days. It will be a slow process through next week, but generally modeled for a ridge to build over the Med/southern Europe early in the week before extending/drifting north across the North Sea/western Scandinavia by next weekend, which would eventually draw in chillier continental air from the east and southeast - but this is still a week away. No Beast From The East showing though, as any deep cold would head for southeast/east Europe. Still, hints that the Atlantic westerlies with wind and rain aren't setting in for weeks on end as is often the case, rather blocking and retreating trop PV is setting the pattern as we head towards winter.

UK Severe Convective & Storm Forecast - Issued 2018-11-11 07:58:54 Valid: 11/11/2018 00z to 12/11/2018 00z THUNDERSTORM OUTLOOK - SUNDAY 11TH NOV 2018 Click here for the full forecastCheck the full storm forecast here

UK Severe Convective & Storm Forecast - Issued 2018-11-10 09:49:32 Valid: 10/10/2018 00z to 11/10/2018 00z THUNDERSTORM OUTLOOK - SATURDAY 10TH NOV 2018 Click here for the full forecastCheck the full storm forecast here

UK Severe Convective & Storm Forecast - Issued 2018-11-10 09:49:32 Valid: 10/10/2018 00z to 11/10/2018 00z THUNDERSTORM OUTLOOK - SATURDAY 10TH NOV 2018 Click here for the full forecastCheck the full storm forecast here

Low pressure close by will bring further heavy and persistent rain to western areas this week, bringing risk of flooding. Friday looks very windy too, as a deep low arrives west of Ireland. View the full blog here

UK Severe Convective & Storm Forecast - Issued 2018-11-06 22:31:53 Valid: 07/11/2018 00z - 08/11/2018 00z THUNDERSTORM OUTLOOK - WEDS 6TH NOVEMBER 2018 Click here for the full forecastCheck the full storm forecast here

Rain around for those venturing out Wednesday evening for Halloween. Rain more widespread Thursday, then ex-Hurricane Oscar could bring a wet and windy weekend. View the full blog here

Hurricane Leslie to make landfall across Portugal tonight, bringing dangerous winds, surf and heavy rainfall. View the full blog here

Still quite a spread in GEFS for Hurricane Leslie track, some loop round and back west to brush Canaries as per NHC official track, while some, like 00z GFS operational track across Portugal and Spain 00z GFS operational Interestingly remnant low of ex-Michael approaches Iberia early next week

Not something you see too often, two ex-Hurricanes approaching SW Europe this weekend, remnant low of Michael fills as it approaches NW Iberia early next week on both 00z EC and GFS, Hurricane Leslie more of a conundrum in that on the National Hurricane Center official track still tracks it east then loops south then west brushing Canaries - whereas latest guidance from EC and GFS take it into Iberia, GFS operational on more northerly track than EC deterministic

UK Severe Convective & Storm Forecast - Issued 2018-10-11 10:24:16 Valid: 11/10/2018 0600 - 12/10/2018 0600 DAY 1 THUNDERSTORM OUTLOOK Click here for the full forecastCheck the full storm forecast here

UK Severe Convective & Storm Forecast - Issued 2018-10-10 16:19:25 Valid: 10/10/2018 1700 - 11/10/2018 0600 DAY 1 THUNDERSTORM OUTLOOK Click here for the full forecastCheck the full storm forecast here

Some media articles have been saying that Hurricane Leslie is heading to the UK, but there is no models confidently forecasting this for now. View the full blog here

Quite a potent heavy shower passed through here in west London recently, heavy rain and very gusty winds with it.

Storm & Convective Forecast Issued 2018-09-21 07:06:59 Valid: 21/09/2018 06z to 22/09/2018 06z THUNDERSTORM OUTLOOK - FRIDAY 21 SEPT 2018 Synopsis Broad upper troughing overspreads higher latitudes of northern Europe and far N Atlantic with upper high over SW Europe - with a strong westrly jet stream flowing across the N Atlantic and UK, a deep surface depression (Storm Bronagh) continues to move away NE toward Norway. A polar westerly or northwesterly flow covers the UK, which will be unstable to SSTs and diurnal surface heating, supporting heavy showers and a few thunderstorms. ... S SCOTLAND, S IRELAND, N ENGLAND, WALES, MIDLANDS, LINCS ... A pool of unseasonably cold air aloft will shift east across the UK this morning on the back of shortwave in strong upper westerlies / jet moving out over the N Sea - creating steep low level lapse rates. This cold air atop seasonally warm SSTs will generate instability that will support scattered showers, some heavy with hail, spreading off coastal areas and well inland this morning across the above areas. As diurnal heating warms the ground, surface heating inland may allow strong enough convection to support isolated thunderstorms too, particularly into the afternoon. These storms accompanied by hail, gusty winds and perhaps localised flooding exacerbated by recent heavy rain. Any storms should fade after dark. Issued by: Nick Finnis

UK Severe Convective & Storm Forecast - Issued 2018-09-21 07:06:59 Valid: 21/09/2018 06z to 22/09/2018 06z THUNDERSTORM OUTLOOK - FRIDAY 21 SEPT 2018 Click here for the full forecastCheck the full storm forecast here

Storm & Convective Forecast Issued 2018-09-20 12:10:49 Valid: 20/09/2018 12z - 21/09/2018 06z THUNDERSTORM OUTLOOK - THURSDAY/FRIDAY 20/21 SEPT 2018 Synopsis Broad upper troughing covers higher latitudes of N Europe / N Atlantic with ridging over southern Europe, a strong westerly jet stream continues to plough over UK and Ireland and on through to Scandinavia, a potent shortwave in the strong upper westerlies will interact with frontal zone lying across southern Britain and out across the N Atlantic, allowing a wave then developing low to form and track NE across England and Wales, deepening as it does so. A squally cold front sweeps SE across England and Wales later, clearing SE England in the early hours. There is potential for strong convection with isolated thunder, damaging convective gusts, intense rainfall and possibly an isolated tornado with the front and also near the deepening low as it exits NE. … ENGLAND and WALES … A warm and rather moist airmass conveyor, with Precipitable Water (PWAT) values approaching 35mm, will be present to south of buckling frontal zone stretching through Wales and central/northern England, which will feature a deepening low moving NE across N England this evening. The warm/moist airmass will become modestly unstable as large-scale ascent and cooling aloft occurs with approaching upper trough and developing surface low. Some embedded convection is likely to develop within pulses of increasingly heavy rainfall spreading NE across Wales, central and N England through the afternoon and evening along buckling frontal zone, although lightning is expected to be isolated, limited by warm layer aloft creating weak lapse rates, intense burst of convective rainfall may lead to some flash-flooding. As the cold front begins to shift S and E through the evening before clearing SE England/E Anglia in the early hours of Friday morning, as the low continues to deepen as it moves out to the North Sea, line convection appears likely to develop along the front – bringing a risk of squally intense rainfall accompanied by lightning locally and strong perhaps damaging wind gusts (50-60mph, locally more with exposure) just ahead of the front. Some flash-flooding and localised wind damage is possible with passage of the squally cold front. Given strong veering of surface winds with frontal passage and strong vertical shear – there is potential for a tornado too with any broken line segments along the cold front, but this potential isolated. ... WESTERN COASTAL AREAS EARLY FRIDAY ... Post cold front polar airmass atop of warm SSTs will create steep lapse rates which will support scattered heavy showers and some weak thunderstorms producing small hail, gusty winds and perhaps localised flooding across western coastal areas. Issued by: Nick Finnis https://www.netweather.tv/weather-forecasts/uk/convective

UK Severe Convective & Storm Forecast - Issued 2018-09-20 12:10:49 Valid: 20/09/2018 12z - 21/09/2018 06z THUNDERSTORM OUTLOOK - THURSDAY/FRIDAY 20/21 SEPT 2018 Click here for the full forecastCheck the full storm forecast here

Met Office news release re: #StormBronagh https://www.metoffice.gov.uk/news/releases/2018/storm-bronagh