jamesbhx

Total predicted accumulations as of tomorrow morning. AROME 1.3km model. 00z run.

The thoughts as of mid afternoon today regarding the airport-specific forecasts for tomorrow were for 60% chance of 0-2cm accumulations, 40% chance of 2-5cm and 10% chance in excess of 5cm for all the London airports. - Industry email.

As someone mentioned earlier I think, the use of amber and red alerts are used sparingly as they trigger various contingency plans with government, local councils, emergency services, utility companies and many more sectors. For example in my industry (aviation based) an amber alert for snow would involve placing additional staff on standby and readying equipment and a red alert would likely involve a shut-down of the operation (one of the options anyway). Both of these cost time and money so the MetO do not take such decisions lightly. For example the main electricity company in the affected area tonight, UKPowerNetworks will most likely have brought in additional engineering staff for their nightshift as part of their contingency plan. They may also be readying additional generating equipment too. This is where the cost comes in.

10m wind gusts on Sunday morning look pretty sporting. Touching 130kph which is 80mph or 70 knots. Surprised no ones mentioned it yet!

Fairly potent cell off the IoW at the moment. Aircraft up to FL380 taking headings to avoid.

I'm in Shoreham by Sea at the moment. Absolutely threw it down about an hour ago. Occasional thunder at the moment but all very embedded. Just grey, murky and very humid!

Just finished a teleconference with various airlines, the Met Office and airports. The highest risk is for Luton and Stansted (and the area in between, sort of M1 to M11) for 1-2cm overnight through til about 6am. No significant accumulations are expected anywhere else in England and whatever falls is most likely be rain or sleet. The greater risk is for low cloud bases and poor visibility associated with rain/drizzle/sleet. I'd say the area defined by a box shaped Luton-Stansted-Cambridge-Milton Keynes has the highest risk of seeing snow which will settle.

Thanks! I've seen a few funnels in that location over the past few years, particularly with a northerly wind versus a sea breeze set up as occurred this afternoon. I'm pleased to report the yacht and aircraft were fine - it looked a lot closer than it appeared!

Two funnels just observed off the coast of Shoreham by Sea, Sussex at approximately 4pm this afternoon.

Another great webcam overlooking the London Eye showing a lot of nearby strikes http://www.guoman.com/corporate/web_cam_page.html

Lightning visible on the Shoreham/Brighton City Airport Webcam http://www.flybrighton.com/webcam

See http://www.radartutorial.eu/07.waves/wa17.en.html for more information on anaprop. Although radar processing does remove a lot of "clutter", it is not completely foolproof and the occasional spots do get through. It is often worse around sunset or sunrise. Flocks of birds, aircraft and even swarms of insects sometimes show up on weather radar. I have even seen the ISS orbiting the earth appear on primary radar (air traffic control) due to refraction of the beam upwards in to space.

A really tricky one to call for this evenings potential. I'd say looking at available data and taking an average across various models and independent forecasts, you're more likely to see some activity the further west you are however the severity would appear to increase the further east you are. So west - higher chance but less severe potential, East - less chance but higher severe potential for anything that develops. I'd probably draw an imaginary east/west line from the Isle of Wight - Oxford - York.

The Shoreham AIrport/Brighton City Airport webcam is quite good as it pans around looking partially at the sky. Can see some development to the SW www.flybrighton.com/webcam

Updated forecast for Shoreham Airport and Gatwick says a 30% of storms between 9pm tonight and 5am tomorrow morning which is encouraging as previously there was nothing forecast. Its based around the area of convection currently around the Channel Islands which has a N/E drift to it.

Heathrow and Gatwick forecasts both indicating a 30% chance of a thunderstorm between 4 and 5am onwards. Anything that does develop is likely to be elevated based on the information at the moment.

Remember that the radar looks up rather than at the ground. It's likely snowing or raining at altitude but not making it to ground level.

Yes quite a few go arounds tonight. I have my own measure of whether the wind is significantly strong or not, and that is when I can hear it on the opposite side of the house to the direction it's blowing from - and right this moment I can hear it.

Hi Dale, Nice project. As someone who makes and deals with METARs daily I thought I'd just give you some background. You're correct in that METARs are timestamped :20 or :50. The observation "window" actually begins 5 minutes before and lasts until 5 minutes past the scheduled METAR time. This is to allow time for the observer to make the observation and enter it in to whatever system they are using. The METARs are then sent via a link to the Met Office for quality control. Once QC'd they are send in to the wider world. Because of this time window, transmission delay (due to message priority) and QC its often at least 5 or 10 minutes after the published time that METARs start to appear on the various websites/apps/platforms etc. There are things called SPECI reports too which are coded METARs but are only send in certain occasions. They are timestamped with the actual time sent, rather than a 50 or 20. They occur when a certain met criterea is met, or a change of weather occurs between two METAR obs which requires updated information to be sent. To my knowledge SPECIs are only sent to the Met Office and to local ATC units rather than the whole world, but if someone knows different then please say! Most of the different weather types you list, Squalls, Volcanic Ash etc are very very rarely reported. It may be better if you coded wind strength as an indicator. This would at least show which stations have stronger winds and which don't. Also as the METAR period exists for 30mins, it would be better if the stations listed still showed up after 30mins, again due to the lag in getting data. Perhaps remove an airfield from the screen if it hasn't had updated METARs for two consecutive observations.

Large CB looking north from Shoreham Airport.

Fairly lively thunderstorm with some very close lightning strikes here in Horsham. About 5-10 minutes of monsoon style rain and hail.

They abandoned the game due to the temporary floodlights getting blown about. No doubt the cameramen up on the scaffold weren't feeling too comfy either! They just mentioned there was a tornado "nearby" but didn't actually show any footage.

Commentators at the Cricket at Canterbury on Sky Sports 2 just mentioned a "tornado" nearby. They were broadcasting from a room somewhere instead the ground taking shelter. Match has been abandoned so they've now gone off air.

Brief funnel cloud observed at Shoreham Airport, West Sussex earlier on their METAR... EGKA 080950Z 20005KT 9999 VCFC SHRA SCT015 SCT020TCU 16/12 Q1015

Funnel cloud reported near Shoreham Airport in Sussex this afternoon. https://twitter.com/brightonairport/status/439392160752758784