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Nick F

Senior forecaster
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Everything posted by Nick F

  1. Even here in south London 50 odd miles from the coast Met Office give 61 mph gust at 3pm on Sunday, imagine it'll be at least 10mph stronger on the south coast. Looks like the Met Office are updating their warnings, perhaps they'll highlight some areas under amber, given the expected strength of winds over populated areas during daytime.
  2. Met Office have named Storm Ciara which will bring widespread gales on Sunday. Staying very unsettled and turning colder early next week, with gales and risk of snow, perhaps another deep low mid-week. View the full blog here
  3. First storm up for Sunday, and for once, the Met Office have named it not Met Eireann. Perhaps might get another named storm for Weds/Thurs next week. Like London buses, all come at once!
  4. 06z GFS brings interesting new slant with the low still headed for the UK Weds/Thurs next week, but will change so just for fun, cold Pm air wrapping underneath the low crossing northern England, could be cold enough to bring snow showers across the south once cold front rain clears.
  5. Fairly consistent outlook last several days beyond early next week's brief cold snap. The stratosphere appears well-mirrored in the troposphere over this side of the northern hemisphere, start of next week the strat PV elongated with one side across the NE Atlantic and other side over Siberia, similar in the troposphere looking at 500mb, strong W/NW flow deep through the atmosphere over the far N Atlantic. However, by day 10 the SPV tightens it's circulation and becomes more rounded while the core drifts back towards Greenland, probably because the strat warming over N America subsides, this mirrored in the troposphere, with a more rounded TPV in the means back over Greenland, strengthening ridging over Europe and a milder SWly flow across the UK. Extended EPS showing this signal for a while now up until day 15. Monday EC 10mb and EPS 500mb mean 00z Day 10 EC 10mb and EPS 500mb mean
  6. Hopefully not a repeat of the Burns' Day Storm of 1990 next week, that brought widespread destructive winds across England & Wales, more widespread damage and greater death toll than Great Storm of 1987, as it happened during the day. Remember being sent home from school early it was so bad. Eerily similar set up to next week with core of TPV over Iceland/ Norwegian Sea. 25 Jan 1990 Next Wednesday
  7. Just pray if we get a low that deep heading our way mid-week, as 18z GFS suggests, it tracks even further south. 90mph+ winds along southern England, even if it is night time, not good for us soft southerners. Significant snow / blizzard for the NE as the low clears
  8. Sunday's potential for severe winds has kind of been overlooked a bit for the more uncertain potential of a deep windstorm mid-week. Sunday's been looking rather windy for a while, with widespread gales, but 12z EC, GEM and now 18z ICON indicates an increasing threat of a rapidly deepening secondary low, tracking further south close to Scotland, rather than further north closer to Iceland, like 12z GFS. This would bring even stronger winds. Wouldn't be surprised if the potential mid-week low trends further south. Perhaps the models trying to adjust to the evidently coupled strat-trop PV relocating this side of the north pole towards northern Europe.
  9. I remember a spell of heavy wet snow giving a layer of slush from a cold westerly flow one evening that month living in Kent, it became ingrained in my mind even though I was young, as it was an unusual direction to get snow from. Anyway, less likely this time round. Long way off I know, but given an uninterrupted WNWly flow from NE Canada to southern Greenland, 00z EC shows how it could be quite snowy Tuesday next week in exposed western areas, Ireland/ N. Ireland, western Scotland, west Wales and NW England.
  10. Shades of Jan 1984 cold zonality in the medium range of the models from early next week, more so the north, where it could be quite snowy at times. Blizzards conditions possible over higher ground, given gales are likely at times. All dependent on whether the jet sinks south enough. 500mb height forecast to become quite low (denoted by the purples on the 500mb/slp charts) as will 850mb height, so even though 850mb temp looks nothing special at -5 to -7c, the height of the 850mb level will be lower than normal. This means a snowflake will have less distance to melt below that level. The TPV core is being displaced over Norwegian Sea 8-10 day timeframe on 00z EC and GFS, note small height rise area over pole on EC too
  11. 00z ECMWF gone off the scale on the +AO index, GFS not quite so strong. Both deterministic runs of EC and GFS bit wayward from the ensemble pack though in FI. Looking at the 10-15 day H500 mean in the extended EPS, looks like we have to get used to anomalously low heights over the N Atlantic and northern Europe. Upper ridge pushing poleward across Alaska, keeping the TPV pinned over Greenland and Iceland. Going to be a rough ride through early Feb for sure.
  12. The problem is a very strong westerly jet around an intense PV will always spawn secondary lows out west which will pull the upper trough axis out west too, pumping milder air in across the UK. Difficult sustaining Pm airmass with such an intense TPV.
  13. Not just T850s. Heights, thicknesses and dew points also need to be considered. Long sea track of Polar maritime flows from the W or NW that aren't direct from the arctic often struggle to have low enough dew points (0C or below) at lower levels on arrival to the UK to support snow to fall to low elevations, due to being well-modified by SSTs. However, low geopotential heights and thicknesses, which indicates a lower freezing levels, and heavy precip can compensate for this. But like you say, a howling gale doesn't help with evaporative cooling, need calmer conditions for that work generally. You can have what looks like favourable T850s for snow with other set-ups, but if the surface dew point is too high, snow's not going to reach the ground.
  14. Depends where the upper trough axis digs, if it digs over Europe, then yes we would be exposed to cold zonality at least, but if the trough axis digs further west over the Atlantic, then we are more likely to end up in Tm airmass in SWly flow. Ensemble means indicating the TPV extended out from the arctic towards NW Europe, some quite low height anomalies over NE Atlantic/NW Europe on medium-extended range. GFS especially is often keen to model the cold uppers in the medium range, but as many are aware it has a cold-bias at this range, so would be wary of the prolonged cold Pm airmasses it shows, because often the GFS ends up correcting the trough axis further west, with the UK ending up on the mild side of the baroclinic zone. But we'll see ...
  15. Oh dear GFS, you really have not covered yourself in glory, total backtrack to a brief northerly then cold high on the 18z. But will there be more twists and turns in the morning?
  16. Clutching straws for the 12z EC to stay firm on the more amplified pattern over the Atlantic early next week (we'll see soon), an interesting forecast discussion from the NWS Portland, Maine office with regards to the coastal storm hesding NE off the Atlantic coast of New England and Canadian Maritimes: **Low confidence potential coastal system late this weekend** Deterministic and ensemble guidance continue to show the development of low pressure off the Mid-Atlantic coast Saturday tracking northeastward towards Nova Scotia Sunday. Recent runs of deterministic guidance suggest that the track of this system will be slightly too far to our east to bring significant impacts. Model ensembles, especially the ECMWF, do show enough members tracking close enough to our area to warrant careful consideration of this system. As mentioned in previous discussions there remains uncertainty in the evolution and track of this system due to multiple pieces of energy moving through the East Coast trough Saturday. The question is whether these pieces of energy can phase at the right time to form a stronger system closer to our area. Another factor to consider is upstream blocking as the upper level pattern remains fairly progressive with the trough quickly moving offshore with heights building over the East Coast starting Monday. Model ensembles show a neutral NAO trending to a slightly -NAO over the next few days with a stronger -NAO leading to more blocking and possibly a closer storm track. Models also show an upper low near Newfoundland Saturday morning. If this upper low can linger into Sunday providing an area of confluence, a more westward storm track is also possible. Overall there a lot of moving parts to this system with current trends favoring a near miss. Will continue to monitor as this system has been visible for several days now and it is still several days from when we could see impacts from this system. National Weather Service Text Product Display FORECAST.WEATHER.GOV
  17. Nick's latest blog looks at the rumours floating around of a major SSW in February. Also, before then, the models are in disagreement for next week over a potential cold northerly. View the full blog here
  18. 00z EC wasn't exactly an outlier for London surface temp next week, certainly plenty of similarly cold members clustered with it, plenty of spread after the 5th. I think the GEFS may well be greatly affected early on by the knock on effects of that winter storm track off eastern US and E Canada late weekend/early next week as to where members go thereafter, certainly they aren't buying amplification on the whole. We await our fate from the 12z runs, if EC jumps ship in favour of the flatter pattern of the other models for early-mid next week, then the Fat Lady will sing.
  19. The divergence between the models post day 6, 00z EC vs GFS, UKMO, GEM, ICON - appears to be how they handle the deepening winter storm off the east coast of US and Canada over the weekend and into next week. EC drives the deep low north up through the Labrador Sea towards Baffin Bay, driving WAA north over the Atlantic towards Greenland and Iceland building a strong mid-Atlantic ridge. Whilst the other models have the low moving NE towards tip of Greenland keeping the upper flow across the N Atlantic a lot flatter. EC T168 GFS T168 GEM T168 US forecasters yesterday placing a lot of uncertainty over the storm developing near the east coast, due to how a shortwave trough in the upper flow coming in off the Pacific deepens as it moves across the US and interacts with frontal boundary over the eastern US. And whether this shortwave trough lifts north or northeast over eastern Canada and upper flow amplifies over the NW Atlantic may impact our fortunes early next week.
  20. 00z GFS op at the cold end of the ensembles spread, but not without support. usually GFS has a good track record with modelling northerlies at range, though the 00z op probably at the extreme end wrt depth of cold and duration, given EC is much less cold and shorter in duration with the northerly, while GEM and ICON don't look to entertain the idea of a northerly at all. So caution required if getting too excited looking at those T850 and precipitation charts from GFS.
  21. Lala land I know, but with a trough dug out across Europe by then and bulging ridge over the Atlantic, chance for a northerly reload?
  22. Probably going to have to take a second warming later in Feb to do more meaningful damage than what is now currently being shown by the models. The SPV won't give in easily this winter.
  23. Well fingers crossed the amplification in the upper flow early-mid next week comes off to allow a proper cold northerly that can bring a flake of snow even to the south. Because it looks, for now, that it may take second warming later in Feb to perhaps finally knock out the wretched strong SPV that has ruined the winter for cold and snow lovers thus far. 18z GFS certainly putting on a good show.
  24. Wasn't aimed at you, apologies if it appears that way, just generally an observation of some knee-jerk reactions to pro met tweets over the years and last few days with the SSW, as if their word is the likely outcome. I agree with you, westerlies is a possible outcome still, particularly as the models appear to be backing away from a SSW ... for now and we're left with a restrengthening SPV. Though the warming is still on and a displacement of the SPV may still work in our favour.
  25. It does concern me that some hang on every word of meteorologists, like they know for sure how the troposphere will be affected by potential changes in the stratosphere beyond 7 days, no-one can know with confidence what will happen, given each model is spewing out different outcomes from elongation, splits or displacements. And his tweet the other day said to 'take with a huge pinch of salt' anyway.
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