Posted by Dr. Eddy Graham on 27 January 2015, 12:49 PM
Yes, it's gonna snow tomorrow (Wed), expect the snow to arrive during the mid-morning. It will come in periodic squalls with hail and high winds, and there is a risk of thunder and lightning again. Severe temporary blizzards are possible over the moors by evening, as temperatures drop to freezing or below.
The snow will lie on Thursday, but later some milder air (incorporated around the top of the 'low') will arrive from the north, with a slight thaw, giving rise to the risk of much ice by Friday, Saturday and Sunday.
Further snow showers, accompanied by strong northerly gales are likely by Saturday/Sunday, blizzards are again possible.
Eddy, Stornoway, Tues 27/1/2015
Posted by Dr. Eddy Graham on 21 January 2015, 12:57 PM
It is reported that a gust of 82.9m/sec (185mph) was recorded during the recent 'hurricane' at the MOD radar site on St. Kilda, at an altitude of 350 metres (on the summit of the 2nd highest hill of the island archipelago). If accepted, this speed would represent a new max wind record for a high altitude site in Scotland (and in the UK as well) - the current record is 173mph from Cairngorm summit on 20 March 1986.I am told that the anemometer has been taken down for testing and calibration before/if any official statement is made. The island staff themselves had to be evacuated by Coastguard helicopter at 3p.m. on the day after the storm.
Posted by Dr. Eddy Graham on 17 January 2015, 9:29 PM
The lowest temperatures since December 2010 are set to occur in the Scottish Highlands over the coming 48-72hrs: Temperatures could dip to as low as -15degC in some sheltered glens.
A snowy NW Highlands and Minch on Monday 19th January 2015 (NASA Terra).
It won't be nearly as cold over the Isles, though severe frosts are still expected, with overnight lows of -4 to -7degC commonplace.
Recognise this island? Why, it's Lewis and Harris of course, as seen by NASA's MODIS satellite sensor flying overhead today The snow-free Westside of Lewis stands out plainly, but most of Harris and east Lewis (except northern Point) are covered in thick snow (the second infra-red image shows the whole of the Scottish Highlands, snow is cyan-blue in colour).
Posted by Dr. Eddy Graham on 14 January 2015, 10:21 AM
A quick update on the weather folks (as of Wed 14/1/2015, 10am): The wind will pick up quickly to a gale from the southeast this (Wed) evening, bringing heavy rain and a thaw (but no storms as bad as last week). Tomorrow, the thaw continues during the day with rain showers. The wind will die completely for a while, only to return as a severe gale from the NW by evening with the snow returning also by Friday. Outlook for weekend: Very cold and further snow, risk down to below -10C in some places!
Snow lying at the Stornoway Town Weather Station (toppled during the recent hurricane).
Posted by Dr. Eddy Graham on 09 January 2015, 3:45 PM
Posted by Dr. Eddy Graham on 08 January 2015, 10:17 PM
Update 10:50am Fri 9 Jan 2015: Friends and family are safe. If I could sum the storm up in a word, it would be the noise - 'the sheer roar like a huge angry monster or animal, unleashed upon us down from the heavens'.
There is debris around the streets of Stornoway, and dozens of hundred-year old beech trees in the Castle Grounds have been blown down. Photos to follow.
Update 3:20am Fri 9 Jan 2015: Well, if you live in Stornoway, you don't need me to tell you - we officially had a hurricane force 12 (mean windspeed 79mph, gusting 113mph) between 1-2am. That is easily Category 1 Hurricane on the Saffir-Simpson scale.
In meteorology, a 'sting jet' is a relatively small region (50-100km wide) of extremely strong winds that hooks around the south side of a rapidly deepening low pressure system. Associated with them is a characteristic hook-shaped cloud (as seen in satellite images), which looks similar to the stinging tail of a scorpion, hence the term "sting jet".
Tonight, as the violent storm approaches, we can see the formation of the cloud hook, from which the sting jet may develop, in the infra-red satellite image (sat24,com) for 21h30 (below):
We are also seeing a huge number of thunderstorms across Uist and Barra this evening as well (Icelandic Met Service)
Sting jets are thought to have responsible for some of the most infamous storms in recent and distant meteorological memory, such as the October 1987 hurricane in SE England, and the 2005 hurricane in the Hebrides.
Stay safely indoors until the storm passes!
Eddie, Stornoway, 22h20 Thursday 8th January 2015
Posted by Dr. Eddy Graham on 07 January 2015, 10:46 AM
Folks, I don't want to dramatise this too much, but we're possibly looking at winds approaching near to, or even exceeding hurricane force early on Friday morning now... thus the storm is likely to be the strongest in the Hebrides since the 2005 'hurricane'.
Hurricane force is when winds exceed 63 knots (74mph) in average wind speed. Gusts typically exceed 100mph. These are structurally damaging, highly dangerous winds and pose a risk to life.
Please, stay safe and I advise everyone to stay indoors during the peak of the storm.
A further violent storm is possible Friday night/Saturday morning (but path and intensity of this is as yet uncertain)
Thunder and lightning are likely too going into Saturday, with snow falling as well (though that is likely to be the least of our worries!).
I'll be posting updates on my Twitter account regularly as long as the power lasts (https://twitter.com/eddy_weather)
Eddie, Stornoway, 7/1/2015
Posted by Dr. Eddy Graham on 06 January 2015, 11:49 AM
UPDATE 6/1/2015, 5:30pm: Some models are diminishing the Sat morning storm significantly - so it's not certain yet by any means.
We're looking at two possible violent storms in the coming days, at least one of which may reach the 'red' category of warning (the highest possible):
- On Thursday night / early Friday morning, a deep storm (<967hPa) with an associated sting jet is expected, with winds up to 90mph
- On Friday night / Saturday morning, a possibly more violent storm (938hPa) could clip N Lewis, with winds approaching 100mph
More later on Twitter... https://twitter.com/eddy_weather
Eddie, Stornoway, Tuesday 6/1/2015, 12 noon
Posted by Dr. Eddy Graham on 05 January 2015, 5:31 PM
Again, it's going to be a very unsettled week ahead (5th-9th Jan 2015), with severe gales likely on Wednesday and the risk of a major storm on Friday. Astronomical tides are high this week, so there could be problems (especially with the southerly gale up the Minch on Wednesday morning).
Hail, sleet, snow and thunderstorms could cause further problems on Thursday and again on Saturday.
The storm on Friday could possibly be quite violent, but its path is yet uncertain.
As always, I recommend you to please keep posted to my regular tweets on the weather as it develops on Twitter at: https://twitter.com/eddy_weather/with_replies
Eddy, Stornoway, Monday 5th Ja.
Posted by Dr. Eddy Graham on 02 January 2015, 12:02 PM
A exceptionally violent hailstorm swept through Stornoway this morning at 11:22am, bringing giant hailstones of over 1cm in diameter. Here are some pictures:
And a video of the storm as it passed through Kennedy Terrace:
And a screenshot of the 11h15 radar clearly shows the hailstorm as a highly reflective mesoscale feature (small area of white/blue colours inside the general orange/yellow/red rainfall reflections) heading east across the Pentland Road towards Stornoway (courtesy www.raintoday.co.uk)
Eddy, Stornoway, 12pm 2/1/2015
Posted by Dr. Eddy Graham on 29 December 2014, 3:18 PM
After the recent quiet, crisp, icy and wintry weather, the New Year is expected to usher in a period of renewed unsettledness, with heavy rain, gales, hail, sleet and squalls returning.
At the moment there is some uncertainty as to when the strongest winds will hit (as the weather systems themselves have yet to develop), but severe gales are likely to occur, especially in the days immediately after the New Year (1st-4th January). It will also turn much colder again by Friday, albeit briefly.
As always, I recommend you to please keep posted to my regular tweets on the weather as it develops on Twitter at: https://twitter.com/eddy_weather/with_replies
Eddy, Stornoway, 30th Dec 2014
Posted by Dr. Eddy Graham on 19 December 2014, 10:00 AM
Wishing everyone a peaceful Christmas 2014, festive season and New Year 2015
Scotland in the Snow (Christmas 2010) - NASA/MODIS/GSFC
Posted by Dr. Eddy Graham on 19 December 2014, 9:46 AM
FINAL UPDATE (Christmas Eve 24/12/14): Yes, the main part of the low will now cross N England (missing the Hebrides) with a severe snowstorm in upland parts, especially on the near continent. Cold, dry east to southeasterly winds may then set in before New Year.
N.B. After last night's thunderstorm, we now have a new record number of thunder days (7) for any month in Stornoway (based on a long-term record kept by J. Webb of Oxford University)- with upwards of 20 individual thunderstorms occurring during the month.
UPDATE (on Tues 23/12/14): The centre of a deep low pressure system envisaged for Sat 27th Dec now looks like passing over southern Scotland/ northern England. If so, this means that the worst weather would miss the Hebrides and N Scotland. However, I recommend to please watch and keep up to date with the forecasts - follow me on Twitter too for the latest updates: https://twitter.com/eddy_weather
Original post (19/12/2014): Staying unsettled, with frequent heavy rain, gales and wintry showers, but a chance of a brief crisper 'Northerly' spell of weather, with frost, ice and perhaps some snow flurries as we head towards Christmas Day... (and there's further risk of more light snow/flurries around 27th/28th)...
N. N.B. A very rare giant hailstone storm affected Ness, Lewis on 18th/19th of December - you can read more about this on Hebrides News at: http://www.hebrides-news.com/hailstones-damage-roofs-201214.html - Happy Festive Season!
Posted by Dr. Eddy Graham on 15 December 2014, 8:56 AM
Thick fluffy snow came tumbling down over Stornoway on Saturday, bringing delight to the young and not so young... Seo aon no dha photos..
Posted by Dr. Eddy Graham on 11 December 2014, 4:27 PM
Latest: There's a risk of another fall of snow for tomorrow (Monday 15th Dec) morning
The focus on the weather has now shifted from thunderstorms & gales to the risk of ice and snow.
Ice is likely tonight (Thursday night) with some accumulation of hail or snow, especially away from the coasts and on hills. Tomorrow (Friday), there is a chance of more substantial snow as the day matures (with early coastal rain quickly turning to snow).
The Calanais Standing Stones in Winter Snow (The Graham Family)
Posted by Dr. Eddy Graham on 10 December 2014, 10:51 PM
"WeatherBomb" Facts and Sparks!
- The number of lightning strike hits over the north of Scotland was the highest since 5th December 2013
- But the total number of thunderstorms within 24hrs is highest I can recall (see map below) - over five individual storms affected Stornoway within 24hrs
- Max wind gusts were: South Uist: 82mph, Bealach na Ba: 105mph; Stornoway: 72mph
Lightning Strikes on 10th December (courtesy Icelandic Met Service)
Why are we getting some many thunderstorms? It's probably the enhanced sea-surface temperatures around the north of Scotland, says Eddy (see orange colours) - NASA ESRL image
A tree came down across the path to Lews Castle College during the storm (Eddie Graham)
The NASA satellite image for today, 10th December (Scotland is under there somewhere!)
Posted by Dr. Eddy Graham on 06 December 2014, 4:16 PM
Latest Update (Tuesday 9/12/2014, 5pm):
Update (Monday 8/12/2014, 9am): It's not looking quite as bad as feared now, with the low pressure 'up' to 942hPa. but we'll still get a severe gale both tomorrow (Tues) and again Wed, with gusts approaching 70mph - these are still hazardous winds, so please be careful. More wintry squalls are likely too, with thunder and lightning again, large hail and sleet/wet snow (the photo below shows the large hailstones in Stornoway on Sunday 7th Dec)
Original post of Sat 5th Dec follows:
Usually a deep low with an intensity of 930hPa or less occurs only about once per decade in the North Atlantic - but last winter we had many such instances..
And so it now seems like this winter doesn't want to be left behind as a poor second-best... because a seriously deep low of 933hPa is forecast to develop south of Iceland at 12h Tue 9th December, passing north of the Hebrides at 12h Wed with a slightly diminished intensity of ~940hPa (see charts below).
Met Office Chart for 12h Tues 9th Dec (above)
Met Office Chart for 12h Wed 10th Dec (above)
At this stage, the strongest winds within the sting jet (hurricane force) appear to be heading for the Faroes and the Rockall Trough on Tues eve, with somewhat reduced winds of Storm Force 10 (perhaps violent storm 11 north of the Butt of Lewis) expected for the Hebrides 12h Wed. But this is still a dangerous storm and anything could happen yet... so I strongly advise everyone to consult the updated weather forecasts in the coming few days.
The astronomical high tide on Tues/Wed in Stornoway is 4.80 to 4.90m - so there could be a risk of storm surge flooding, with a correspondingly huge swell out to sea on the west coast.
Meanwhile, we'll have some (very) temporary snow tomorrow (Sunday) - the deep cold Arctic air is already making its way south of Iceland as I type (see below) - the thunderstorm anvils are turning anti-cyclonically (plenty lightning sferics have already been reported), indicating powerful squalls, snow, hail, thunder, lightning and very deep cold air - so we may even get a visit from 'nan Seachd Siantan' again...
Updates shall follow..
Eddy, Stornoway, Sat 6th Dec 2014
Posted by Dr. Eddy Graham on 03 December 2014, 9:56 AM
Hail squalls and snow flurries are likely to affect Stornoway and the Isles this coming Friday, thawing Saturday, only to return again Sunday. Current indications are that any snow is unlikely to lie for long.
On top of this, following the massive influx of cold Canadian air that is causing the snow, severe gales, or even storms, are likely early next week. As of yet, it is uncertain exactly where and when the storms may hit, but we should know in better detail by this weekend.
Eddie, Stornoway, 3 December 2014
Update Thurs 4/12/14: Latest model output suggests hail/sleet during Friday, freezing overnight on roads; thaw Saturday; more substantial snow showers (away from onshore coasts) on Sunday, lying temporarily. Gales early next week.
Friday update (6pm 5/12/14): Still the same as above. A nasty swell on west coast too by Monday.
Posted by Dr. Eddy Graham on 01 December 2014, 9:29 PM
The following spectacular NASA MODIS satellite image, taken on the morning of Sunday 30 November, shows the clouds parting from around the Isle of Lewis (Scotland).
Eddy, Stornoway, 30 Nov 2014
This has happened because the airflow is perturbed by the mountains of Harris and Uig (to the south and southwest of the island). The reason the mountains and land are able to do this is because the cloud layer was very low and shallow (thinner than the height of the mountains), and also because the airflow was very mild and stable (with no significant decrease in air temperature with height).
A telephoto zoom shot (above, taken through a 10 X 50 binocular eyepiece, from a distance of approximately 50km) shows this cloud being forced to ascend the Clisham mountain (2622 feet, 799 metres) and then descending on the near-side in a strange "waterfall" fashion. This unusual meteorological situation is known as the "foehn" (after the name of a warm wind in the Alps).
Meanwhile the satellite image from two days earlier (above, 28 November) shows a crystal clear sky over the whole of NW Scotland, the Minches and the Hebrides. The only cloud of any note are a few blobs of cumulus over the NW Highlands in Sutherland, over Beinn Mhor & Hecla in South Uist, and two blobs over South Harris. What looks like snow in the glens of the central Highlands is actually the highly reflective top of fog filling the valleys. Look closely, you can see these 'fingers' of fog filling the glens in a near-perfect (but inverted) reflection of topography!
Eddie, Stornoway, 1 December 2014.
Posted by Dr. Eddy Graham on 30 November 2014, 11:26 PM
The Halcyon days are meant to be a period of 7 fine days, occurring during early winter, when (in Greek mythology) Aeolus restrained his winds in order to allow for the kingfishers (Halcyons) to lay their eggs.
Well, it has been a bit more than 7 days already... indeed, what beautiful weather we have been having for the past 2-3 weeks across the Hebrides and NW Scotland - it seems as though winter has been delayed or indefinitely postponed... the grass is still growing and air temperatures have been more akin with October...
More details shall be forthcoming in the next issue of the Stornoway Gazette, but here are a few nice photographs from the Stornoway Castle Grounds over the past 3-4 days.
A great view of Stornoway from Gallow's Hill on 28 November:
And a mirror-still Stornoway Harbour on 28 November:
Finally a nice reflection in the still water of the duck pond!
Eddy, Stornoway, 30 Nov 2014
Posted by Dr. Eddy Graham on 27 November 2014, 10:23 PM
Vene, vidi... amavit (I came, I saw, I fell in love...)
And well, no visit to Rome is complete without an audience with Papa Francesco himself (and the Italian football team)...
Or indeed a wee spin in a Ferrari...
Posted by Dr. Eddy Graham on 27 November 2014, 10:02 PM
All roads lead to Rome - and at night they led me for a wondrous week across this truly magnificent city, fueled by a nearly endless supply of Italian espresso and gelato (Italian ice cream).
Posted by Dr. Eddy Graham on 19 November 2014, 1:05 PM
As expected, we've been having some lovely dry, fine and exceptionally mild easterly weather lately. Current indications indicate that it will last until Friday night/Saturday (21st/22nd November), before more seasonal heavy rain, showers and south-westerly winds return over the weekend and into next week. It will turn temporarily much colder for a time Sat/Sun too (with sleet on the hills), but will quickly turn mild again next week.
Eddie, Stornoway, 18 Nov 2014
Posted by Dr. Eddy Graham on 09 November 2014, 10:36 PM
Yes, as indicated in my last post of more than 1 week ago - high pressure is indeed building to the north of Scotland, meaning the resulting east and south-east winds are likely to bring good drying conditions and fine skies for several days across the Hebrides and Northwest Highlands.
It won't be rain-free all the time, but there'll certainly be a lot less rain than we've had during the past 3-4 weeks. So some good news indeed!
Eddie, Stornoway, 9 Nov 2014
Posted by Dr. Eddy Graham on 02 November 2014, 12:49 PM
Despite October & November being two of the wettest months of the year normally, it has been exceptionally wet recently - indeed it has been near-record wet.
A quick look at the weather stats for Stornoway town show that 150mm (6 inches) of rain fell in final 15 days of the October. As the graph shows below, 15-day running totals of 150+mm have only occurred three times in the past 15 years, so yes, we are having a particularly unusual wet spell at the moment, equivalent to an event of about once in every 5 years.
Another 18.1mm fell during the day on Saturday 1st November - probably increasing the above odds yet further... but there are tentative signs the weather may finally quieten down by late next week as high pressure builds from the east - thank heavens!
Eddy, Stornoway, 2 Nov 2014