Jump to content
Problems logging in? ×
Snow?
Local
Radar
Cold?

Ian Docwra

Members
  • Posts

    251
  • Joined

  • Last visited

Posts posted by Ian Docwra

  1. Today's summary for my location:

    Max. temp. -1.3C.

    Snow depth : approx. 3cm, drifts to 10cm.

    Weather light snow all day.

    Dry, powdery snow almost everywhere but still some wet patches lower in the garden which were saturated before the cold arrived.  Two ponds - upper one (in loamy soil) not frozen, lower one (in sandy soil) - partially frozen/slushy.  Surrounding hills (Downs) up to 230m are more deeply covered from around 170m upwards.

    • Like 1
  2. 2 minutes ago, Met4Cast said:

    Possible Kent streamer tonight transitioning to Londons streamer tomorrow.

    YES.thumb.png.d5e2110216bab894c027d96ae4bd22b3.png

    Shaded area: Highest risk of snow this evening and tonight, uncertain how much will accumulate, depends how intense we can get the showers/how prolonged they are. 

    Black line: This is the area at risk during tomorrow as winds become much more easterly. UKV has developing convergence zone later tomorrow afternoon>evening which could pep up showers, though current precip modelling isn't really showing this very well.

    Will there be enough moisture gather for the London streamer given a due easterly flow?  The orange area pivoting north would suit me very well, BTW!

  3. 1 minute ago, chionomaniac said:

    The snow melt is 100% ground temps. I have just watched the phenomenon in my back garden.  The air temperature just above the ground is -1.2°C. When the snow hits the pavement, or bare soil, it melts very quickly.  However, where the grass and bushes are tall enough to offer a bit of protection from the ground, the snow settles, likewise outdoor window ledges and roofs. It also is sticking on manhole covers, and the outside door mat where bristles keep the snow away from the surface. I have a small paved area with steps, that I have noticed have air bricks underneath them. The snow has melted right up to the steps but stuck on the air brick borne steps - so the air bricks are providing a cold insulating barrier away from the ground to let this occur.

    It’s no surprise really, with weeks of heavy rain, a warmer and saturated water table, and no significant harsh frosts prior to the snow, it didn’t stand a chance in these areas.

    Indeed - as I said on Saturday.  The message, it seems, takes time to get through the barrage of optimism that everything would instantly freeze solid!

  4. 13 minutes ago, jamesgold said:

    Yep that’s good, get the heavy cloud out the way and showers can drive in. I’d say it looks pretty good for us in NW Kent, Bexley, Bromley etc (at the moment)

    Clearing the "heavy cloud" won't achieve anything on its own - in sunny weather, losing cloud allows convection to start, but obviously warms the surface in the process.  Now, nearly at sunset, that won't happen so the lack of cloud, if anything, chills the air near the ground and reduces convection.  

  5. 23 minutes ago, Jason M said:

    Absolutely. It’s what fergieweather would refer to as ‘depth temps’. That’s why yesterday was a bust for many of us. The skies cleared here for several hours last night and within about 15 mins everything froze solid. It then snowed and settled without any problems and we have had virtually no melt today whatsoever. A couple of hours under clear skies and it’s a different situation.

    the mini beast that followed the main event in 2018 was the same. I remember hours of snow falling and it just melting on contact despite the temp not rising above zero for 24 hours before.

    This what I was saying on Saturday, before the snow arrived, and was part of the reason I was sceptical about immediate or even medium term accumulation and then longevity.  The ground had been warmed for quite a while and it takes time to lose that heat.   However, I was firmly assured by the experts here that, effectively, the ground would freeze instantly and not a flake would be 'wasted'.  Hey ho.

  6. 4 minutes ago, UKSupercell said:

    Any idea when these supposed streamers will form and push across London into the Guildford to Petersfield area? BBC says heavy snow all of tomorrow for my area near Petersfield (lol) but MO shows little. 

    I have a slight feeling one may be starting now - there is a heavy streamer in West London and an increasing intensity (over a wider area than a true streamer) from Kent westwards.  We are seeing larger, and more, flakes now with a slightly lighter wind.

    • Like 3
    • Thanks 1
  7. An interesting phenomenon here - the temperature has been at between +0.2C and +0.4C all afternoon.  We have a latticed metal patio table and the snow has only sporadically settled on it, otherwise melting.  Now, at +0.4C, there are long icicles hanging down.  I presume the strong wind has caused evaporation from the metal and cooled it enough for freezing to occur.  This may also explain some others finding metal objects with ice while snow melts - it really is that marginal.

    • Like 1
  8. 5 minutes ago, Captain Shortwave said:

    It is fair to say that today’s event is a little on the usual side. As such a wider envelop was needed (the set posed a genuine risk of disruptive snow and blizzards in the east). Some places do appear to have already seen over 4 inches (still falling), a lot of others unfortunately have not seen as much as was potentially predicted.

    I will say that in general the models did converge on the right track better than the last regional snow event. It is just an issue with the amounts people got.

    I think the issue has been the failure to get the temperatures right - the track predicition is OK but the temperatures were widely predicted to be significantly lower from the same track, which makes me wonder about the data used.  The upshot has been that many have seen falling snow but not the accumulations that were implied by those who said (vehemently!) that the one thing people shouldn't worry about was that it wouldn't be cold enough.

  9. I have an interesting situation in my garden.  Our lawn slopes up to the house significantly, and snow is lying on the higher parts while the lower area is still mostly green.  I suspect the slope will be draining meltwater better to allow more settling but I also know that the freezing level is very, very close to us (my station is at the lower part and shows +0.2C).  It makes me wonder if I have a snowline running across my garden!  All good fun.

  10. 1 minute ago, Paul Sherman said:

    And thats the amazing part of it, for every Moron there are 100 people who understand just how hard it is.

    I did a High Risk in Kansas on a Tour once in 2008 , a PDS Tornado Watch was Issued and the dryline bubbled into life, Ma Nature had other ideas and not 1 scrap of Precip fell and the clouds bubbled away to Orphan Anvils, what did we do, well we took it on the chin and said Ma Nature won that little skirmish, we didnt hold it against her and nobody thought any worse after a few beers. These things happen, and then on days when its a Marginal Non Zero Tornado day you luck out on a stunning High Plains Stovepipe, rough with the smooth with the weather and nobody can call it completely correct if they tell you they can they are lying 

    Quite.  The surprising part of all this for me is not the exact position of the snow (that's always very hard) but that the widespread temperatures have been significantly higher than expected, when the talk was of sub-zero everywhere, meaning, of course, accumulation everywhere to some extent.  It's almost as it the abnormal SST has passed the models by, because the flow direction is very much as forecast.

    • Like 1
  11. 3 minutes ago, seb said:

    I really don’t understand this panic and talks of the bust of the century.

    Layman’s terms:

    1. Darcy is a low pressure system stretching from northern central Europe to the med. It’s not a storm that’s meant to hit us like system coming from the Atlantic do. It’s pumping mild air and a lot of moisture north where it meets cold air in an East > West airflow. The moist air gets stuck as it can move further north due to high pressure.

    2. Our region has been sub zero since 7am and it has been snowing since. Models have been showing pretty much exactly what has happened so far, including a lack of accumulations.

    3. Temps will drop to -3 this evening while snow will continue to push in from the North Sea. It will accumulate. This will continue through the night and a good part of tomorrow. 
     

    4. If we are lucky we will then see showers push in from the North Sea thanks to the Easterly flow and the warm sea.

    The forecast says exactly that as do the warnings. The amber only came into force this morning and doesn’t expire until noon tomorrow. Based on the drifts already happening on the Downs with some country lanes being close to impassable and those conditions bound to spread and worse, the warning is spot on.

     

    Yes, 'Darcy' was never going to cross/sit over us, but many were claiming that its frontal snow was going to be very significant across the region.  It missed us completely and moved away to the east.   You say "our region has been sub-zero", but only parts of Kent and significantly higher areas elsewhere have been - the region is the whole SE, from Oxfordshire to Kent and most of that has been in the range +0.5C to +3C, whereas it was widely predicted here that the whole region would be <0C today.  While the sky remains cloudy and the wind is strong, yet with a high dewpoint, there is no reason to suppose that the temperature will drop more than a fraction overnight, unless a different flow is expected.  The latter may be the case, but it isn't apparent, which means that more of the same might be expected - i.e. lying snow above, say, 100m, and slush/wet below.

    • Like 1
  12. 2 minutes ago, Met4Cast said:

    Oh my f**king god.

    How many times does it need saying?

    1. The amber doesn't expire until tomorrow midday

    2. Widespread heavy showers & streamers are going to follow later, tonight, and through much of the day tomorrow.

    Stop calling it a "bust" just because your area hasn't been buried by 10 foot of snow yet. The event has barely even started.

    I don't think very many are saying there won't be any significant snow, but the 'Darcy' phase was badly out, and the supposedly guaranteed sub-zero temperatures also haven't materialised.  I suspect there may be more chances to come of sub-zero temperatures to allow whatever falls to settle, but, given the North Sea's unusual warmth this year, it's by no means certain.  What leaves Holland at -3C/-2C gets here quite widely at 0C/+1C after travelling over +5/+6C water.

    • Like 3
×
×
  • Create New...