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Nick F

Senior forecaster
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Nick F last won the day on August 9 2018

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About Nick F

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    Specialising in severe weather

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    South Norwood, London (home), Hounslow/Heathrow (work)
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    Weather - particularly thunderstorms, growing plants, walking, cycling, cooking and good food, wine.

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  1. I wouldn’t have much confidence in model ops past day 6 at the moment, seem to be quite noticeable intra-model differences in the track of the jet into Western Europe and expansion of higher heights eastwards from the Greenland upper ridge later next week. 18z GFS and earlier 12z GFS lowering heights more into Central Europe than EC - which goes on to merge the far N Atlantic upper vortex with the vortex over Barents Sea thus raises heights over SW Europe. Deep cold still way out of reach, but we could get ‘faux’ cold continental flow instead in run up to Christmas.
  2. Given there is such large differences between EC and GFS with Friday night's low track, Ec has it track across S England GFS across N England, wouldn't even consider snow potential as far away as early Sunday for now. 00z EC doesn't even show GFS's low for early Sun, though has a frontal wave or trough moving NE, which brings snow to Wales and N England for a time. This far off, could change ...
  3. UK Severe Convective & Storm Forecast - Issued 2019-12-11 09:00:50 Valid: 11/12/2019 0600 - 12/12/2019 0600 CONVECTIVE / STORM FORECAST - WEDS 11TH DEC 2019 Click here for the full forecast
  4. Nothing particularly inspiring up to day 10 on GFS, unless it’s wet and windy you like. Trouble is, secondary lows keep forming out west due to deep cold coming out of Canada causing a steep temp gradient over NW Atlantic, these lows forming to SW of parent low north of Scotland holding back the coldest PM air, so zonal flow not really cold enough to bring any snow away from high ground in the north. Just going to have to wait for the strengthening trop PV to weaken or at least dig further southeast into Europe; no signs atm of any real shake up of the zonal pattern for now.
  5. Well, it looks like a rampant zonal jet is in the driving seat for the foreseeable future until something weakens the strengthening and expanding low heights / trop PV to our N and NW - but model ensemble teleconnections forecasts point to a +NAO for the 1st half of Dec for now. So often windy, sometimes wet, alternating Tm and Pm airmasses. GFS and EC hinting from late next week and through weekend some cold zonality, though often the coldness of the uppers in a W or NW flows tend to be toned down as we drawer nearer the potential. We've already seen a cold arctic northerly downgrade then vanish for Election Day. The one thing that may help in lessening the moderation of the cold zonal Pm flows sources from deep cold air over Northern Canada is Atlantic SSTs that are below average to the west of British Isles according to SST anomalies below:
  6. The low leaving southern tip of Greenland Tuesday, which goes on to be the potential ‘trigger’ for an arctic northerly on Thursday and Friday next week on previous runs, deeper on this run and thus forcing the low on a more northerly trajectory towards the UK. This more northerly track could delay the colder sub -5C T850 air sinking across all of the UK, though fortunately again on the 18z it gets the -5C line to the south by Friday. Not quite so much upper flow amplification upstream following this trigger low either. But no huge downgrades for now, remarkably fairly consistent up to the end of next week with the evolution, given the timeframe.
  7. Although it's still 9 days away, and subject to change, the weather models have have several runs indicating a cold Election Day Thursday next week, even with a risk of snow. View the full blog here
  8. If high pressure doesn't build in too quickly, always potential for troughs or slider low in the cold N or NWly flow to bring more organised sleet/snow inland away from the usual windward or coastal areas which see showers in these arctic or polar flows. Then of course there is a southerly tracking jet near the south coast shown that could bring secondary lows along the south that may interact with cold air draining down from the north. Not saying these scenarios are on the cards, as too far off still to say we will even get a northerly, but highlights routes for wintry precipitation almost anywhere in such a setup.
  9. I think the less said the better with regards to the EC weeklies updated this evening, seems to develop troughing in the Atlantic to our west from mid-month, though it does hint at higher heights over Scandinavia as the run goes on. EC longer range never that reliable anyway, so lets not worry too much, at least the potential for a northerly later next week on cue to coincide with the General Election is still on track, that's the 4th consecutive GFS operational run now to show it with a fairly similar evolution and timing. Really need the jet to dive further south in the wake of this northerly than shown, so we don't get mild sectors pushing out the cold air too easily. But … one step at a time ...
  10. Looks primed on 06z thus far for the arctic floodgates to open again for General Election Day Shame it's too far out to have confidence in getting a clean northerly flow direct from the arctic for all.
  11. The real interest showing in the models, i.e. a potentially cold northerly, frustratingly staying out at day 9-10 in the model runs. Originally it was looking like the period 8-10 Dec showed potential for a cold northerly, now goal post has moved to 10-12 Dec … waiting for that amplification in the flow to develop N over the N Atlantic. But I guess most of us seasoned model watchers are well-versed with this teasing by NWP. The background atmospheric drivers on a more global picture in the northern hemisphere aren't particularly conducive to any big upheaval in the pattern in the next few weeks that could lock us into a blocked pattern, MJO looks like crawling slowly through phases 2-3 or staying in COD … so not really impetus for change forced by the tropics. The trop PV organising and expanding over northern Canada and Greenland - which will increase energy over the N Atlantic. On a positive note ... -There are hints from GFS/GEFS of the AO and NAO going negative around mid-month, so small signs here and there that could be some steps to change. -GEFS strat zonal wind forecasts still heading in the right direction … so still that chance of a SSW later this month. -Outlook not particularly mild or particularly cold, looks average December fare. Any cold arctic incursions transitory, due to too much zonal upper flow energy over the Atlantic under the trop PV wrapping up, but any arctic incursions could bring some snow briefly to lower levels, northern hills certainly should see some white stuff next week in the PM flow.
  12. Morning all. Cold over the next few days under high pressure (Sun-Weds) with inland temps perhaps struggling to get any higher than low to mid single figures during the day, perhaps staying around 0C where fog lingers. So feeling nice and seasonal, even festive for those Xmas shopping, for the opening of December. Thursday and Friday looks to turn milder for most as pressure falls from the NW and a southwesterly wind picks up, perhaps gales across Scotland Thurs night. However, it does look like a brief shot of PM air may visit this time next week, perhaps giving a little snow to Scottish hills for a time. But thereafter we could be at the mercy of energy feeding downstream over the N Atlantic, energy that feeds east from the Canadian vortex may hamper efforts to build a decent enough ridge in the Atlantic to get a half-decent northerly - see 00z EPS mean below. But we'll have to wait how this pans out over next few days.
  13. Models have been hinting at a northerly in the 8-10th Dec timeframe over last few runs, still too far away to pin ones hopes on it occuring, but the 00z EPS 500mb mean this morning looks more encouraging for this to occur than the 00z GEFS 500mb mean - which has a weaker Atlantic ridging signal. 00z EPS T240 00z GEFS T240 Like the look of the arctic ridge separating the trop vortices over Scandi, Canada and Bering Sea on 00z EPS mean.
  14. To be fair, Knocker was right to point out that the 'Short milder blip is all it is now mid next week' comment was not correct based on NWP forecasts for cold temperatures at the surface across England and Wales early to middle part of next week under high pressure. It does turn milder across England and Wales later next week into the following weekend, as pressure falls from the NW and a southwesterly wind picks up.
  15. UK Severe Convective & Storm Forecast - Issued 2019-11-26 11:16:36 Valid: 26/11/2019 0600 - 27/11/2019 0600 CONVECTIVE / STORM FORECAST - TUES 26TH NOV 2019 Click here for the full forecast
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