A low pressure system will bring showery conditions and a risk of thunderstorms to Scotland over the next few days. Showers will develop across western areas on Wednesday morning and spread eastward, with some heavy downpours possible. Thunderstorms may occur in northern and western parts. Showers will continue on Thursday with a risk of lightning, lingering into Friday before gradually easing. Unsettled weather with further showers is expected through the following week.

1. General Forecast - Perth, Angus, Aberdeen, Moray Firth
A mostly dry start but showers are soon expected to develop and spread from the west. Many of the showers may well die away this afternoon although one or two are still possible, especially in the north and west. Tonight, mostly dry but again, the odd shower may affect
more northern and western parts of the region, especially later in the night.
General Forecast - Western Isles, NW & Cent Highlands, Skye, Argyll
A rather blustery day with large amounts of cloud in general and a risk of showers. A few heavy showers are possible. Lightning looks unlikely but can not be completely ruled out. Winds easing a touch this evening and tonight. There will again be large areas of cloud and
further showers with these becoming more organised and lengthier later on.
General Forecast - Shetland, Orkney, NE Caithness
Large amounts of cloud today with brisk winds driving in a scattering of showers, a few of which could be heavy. The continued chance of showers overnight.
Synoptic Discussion and Confidence
An area of low pressure will drift east then north-east to the north of Scotland over the coming 24 hours. In the westerly flow, on the southern flank of this depression, there will be a relatively tight pressure gradient, feeding in a succession of showers. These will merge at
times as several fronts and troughs move across the country. Overnight, a new developing area of low pressure will begin to form and drift south to the west of the country. This may instigate further showery activity in the west towards morning.
Upland Forecast
No differences to the lowland forecast.
Scheduled Utilities Forecast - SHEPD (North) - Wednesday 30 Jul 2014
Day 1 of 5 (0600 Wednesday 30th July to 0600 Thursday 31st July)

2. Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust
15 W 35 15 W 25 15 W 30 15 W 35 15 W 35 15 W 35 15 W 35 25 W 35 20 W 30
15 W 35 10 W 25 15 W 35 10 W 35 15 W 35 15 SW 35 10 W 30 20 NW 35 20 NW 30
10 SW 30 10 W 20 10 W 25 10 SW 25 10 W 30 10 SW 25 5 NW 25 15 NW 30 15 NW 25
10 W 15 5 W 15 10 W 15 10 SW 15 10 N 15 10 SW 15 5 NE 10 10 N 20 15 NW 25
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
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Icing
Height
(m)
Snow
(cm)
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Icing
Height
(m)
Snow
(cm)
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Icing
Height
(m)
Snow
(cm)
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Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A
0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A
Area Perth & Angus Aberdeenshire Moray Firth Argyll & West Highland NW Highland & Skye Central Highlands Western Isles Orkney & NE Caithness Shetland Area
Risk (RAG) Green Green Green Green Green Green Green Green Green Risk (RAG)
Temp
(Max/Min)
20 11 21 11 19 12 17 10 16 11 20 10 17 12 17 12 16 12
Temp
(Max/Min)
Wind Wind
06h-12h 06h-12h
12h-18h 12h-18h
18h-00h 18h-00h
00h-06h 00h-06h
Rain (mm) Rain (mm)
06h-18h 0 - 1.0 0 - 1.0 0 - 1.0 0.5 - 1.3 2.9 - 7.0 0.2 - 1.2 1.4 - 3.5 1.7 - 4.1 1.6 - 2.6 06h-18h
18h-06h 0 - 1.0 0 - 1.0 0 - 1.0 0.5 - 1.9 0.9 - 1.7 0.1 - 1.1 0.5 - 1.4 0.2 - 1.2 0.2 - 1.2 18h-06h
Snow/Line
Icing
Snow/Line
Icing
06h-18h 06h-18h
18h-06h 18h-06h
Lightning Lightning
06h-18h 3 3 3 3 3 3 3 3 3 06h-18h
18h-06h 3 3 3 3 3 3 3 3 3 18h-06h

3. General Forecast - Perth, Angus, Aberdeen, Moray Firth
A dry start but with showery rain developing through the morning in places. Thundery downpours in the afternoon, especially so in the north of the region. Thundery showers will then soon move away in the evening (lightning risk receding by 20-2100) leaving the odd left-over
shower overnight but also clear periods.
General Forecast - Western Isles, NW & Cent Highlands, Skye, Argyll
Showery spells of rain developing and becoming locally heavy and potentially thundery (lightning risk from around 10-1100). Further thundery downpours in to the afternoon although It will become somewhat drier across the Western Isles. Showers and thunderstorms easing
through the evening with the risk of lightning receding by around 20-2100. The odd left over shower overnight but also some clear breaks.
General Forecast - Shetland, Orkney, NE Caithness
Showery rain developing through the day across the mainland bringing the small risk of infrequent lightning by around noon. Elsewhere, just a chance of the odd shower. The lightning risk will recede from NE Caithness by around 2000, leaving the night time period with the odd
shower but in general, plenty of dry weather.
Synoptic Discussion and Confidence
A shallow but developing area of low pressure is expected across Scotland, increasing instability and bringing about showery spells of rain with a risk of thunderstorms. Low pressure will linger through the night although as it becomes cooler, so showery activity is expected to
subside.
Upland Forecast
No differences to the lowland forecast.
Day 2 of 5 (0600 Thursday 31st July to 0600 Friday 1st August)

4. Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust
10 NW 15 5 E 15 10 SW 20 10 W 20 10 NE 15 10 SW 20 5 E 15 10 NE 15 15 NW 20
10 NW 15 5 NE 15 10 SW 25 10 W 25 10 NE 15 10 S 25 5 NE 15 5 NE 15 10 NW 20
5 NE 15 5 N 10 10 NW 20 5 NE 20 5 NE 15 5 N 20 5 NE 15 10 NE 10 10 NW 10
10 NE 10 5 NE 10 10 E 10 5 E 10 10 E 10 5 E 10 10 NE 15 10 NE 15 5 N 10
Snow
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Snow
(cm)
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Icing
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(m)
Snow
(cm)
Line
Icing
Height
(m)
0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A
0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A
Area Perth & Angus Aberdeenshire Moray Firth Argyll & West Highland NW Highland & Skye Central Highlands Western Isles Orkney & NE Caithness Shetland Area
Risk (RAG) Green Green Green Green Green Green Green Green Green Risk (RAG)
Temp
(Max/Min)
18 10 17 10 16 10 17 9 16 9 17 9 16 11 15 9 15 9
Temp
(Max/Min)
Wind Wind
06h-12h 06h-12h
12h-18h 12h-18h
18h-00h 18h-00h
00h-06h 00h-06h
Rain (mm) Rain (mm)
06h-18h 1.5 - 5.0 1.8 - 3.8 4.2 - 7.0 3.7 - 11.0 1.8 - 6.0 3.5 - 9.0 0.8 - 1.6 0.8 - 2.0 0 - 1.0 06h-18h
18h-06h 0.5 - 2.2 1.3 - 3.0 2.4 - 3.6 0.5 - 2.4 0.3 - 1.4 1.0 - 2.6 0 - 1.0 0.1 - 1.0 0 - 1.0 18h-06h
Snow/Line
Icing
Snow/Line
Icing
06h-18h 06h-18h
18h-06h 18h-06h
Lightning Lightning
06h-18h 2C 2C 2C 2C 2C 2C 2C 2D 3 06h-18h
18h-06h 2C 2C 2C 2D 2C 2C 3 2D 3 18h-06h

5. General Forecast - Perth, Angus, Aberdeen, Moray Firth
Further showers or longer spells of rain developing with a risk of lightning strikes. The
rain will linger in places in to the night although the lightning risk should recede.
General Forecast - Western Isles, NW & Cent Highlands, Skye, Argyll
Further showers or longer spells of rain developing with a risk of lightning strikes.
However, the Western Isles and far north of NW Highland may escape much of the
wet weather. The rain will linger in places overnight although the lightning risk should
recede.
General Forecast - Shetland, Orkney, NE Caithness
The odd shower. Otherwise, variable cloud and sunny spells. A growing risk of
persistent rain overnight.
General Forecast - Perth, Angus, Aberdeen, Moray Firth
A risk of showers, some prolonged. Persistent rain moving north overnight with
embedded lightning.
General Forecast - Western Isles, NW & Cent Highlands, Skye, Argyll
A few showers. Persistent, potentially thundery rain overnight, especially towards the
east.
General Forecast - Shetland, Orkney, NE Caithness
Showers or longer spells of rain. The risk of infrequent lightning overnight.
General Forecast - Perth, Angus, Aberdeen, Moray Firth
Any thundery rain easing to leave the odd left over shower during the afternoon,
evening and night.
General Forecast - Western Isles, NW & Cent Highlands, Skye, Argyll
Any thundery rain easing to leave the odd left over shower during the afternoon,
evening and night.
General Forecast - Shetland, Orkney, NE Caithness
Thundery rain, easing from the south later on in the day. Turning mostly dry
overnight.
Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust Mean Dir'n Gust
20 NE 30 20 NE 35 20 NE 35 20 N 30 20 NE 35 25 NE 40 20 SW 35 25 S 40 25 SW 40
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
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Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
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Icing
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Snow
(cm)
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Icing
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Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
Snow
(cm)
Line
Icing
Height
(m)
0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A 0.0 Nil N/A
Day 3 of 5 (0600 Friday 1st August to 0600 Saturday 2nd August) Day 4 of 5 (0600 Saturday 2nd August to 0600 Sunday 3rd August) Day 5 of 5 (0600 Sunday 3rd August to 0600 Monday 4th August)
Area
Day Three Day Four Day Five
Perth, Angus, Aberdeen,
Moray Firth
Western Isles, NW & Cent
Highlands, Skye, Argyll
Shetland, Orkney, NE
Caithness
Perth, Angus, Aberdeen,
Moray Firth
Western Isles, NW & Cent
Highlands, Skye, Argyll
Shetland, Orkney, NE
Caithness
Perth, Angus, Aberdeen,
Moray Firth
Western Isles, NW & Cent
Highlands, Skye, Argyll
Shetland, Orkney, NE
Caithness
Risk
(RAG)
Green Green Green Green Green Green Green Green Green
Temp
(Max/Min)
17 11 17 9 15 11 18 10 18 9 17 11 20 11 19 9 18 11
Wind
24 hours
Rain (mm) 24 hour total 24 hour total 24 hour total 24 hour total 24 hour total 24 hour total 24 hour total 24 hour total 24 hour total
24 hours 13 - 29 6 - 21 6 - 20 3 - 12 4 - 12 6 - 19 2 - 8 2 - 6 5 - 20
Snow/Line
Icing
24 hours
Lightning
24 hours 2C 2C 3 2C 2D 2D 2C 2D 2D
Days 6 to 10 (0600 Monday 4th August to 0600 Saturday 9th August)
Outlook
It is set to remain rather unsettled as low pressure sit close to the UK. Showers or some longer spells of rain are likely at times and with these, the threat of lightning.

6. Overall risk of disruption
Severe risk Red
Significant risk Amber
No risk Green
The above reflects the worst case of any of the following
Wind Gusts (mph) - 1st November - 31st March
S, SW, W & NW
Islands 50 55 60 65 70 75 80 85 90 95
West Mainland 50 55 60 65 70 75 80 85 90 95
East Mainland 50 55 60 65 70 75 80 85 90 95
N, NE, E & SE
Islands 50 55 60 65 70 75 80 85 90 95
West Mainland 50 55 60 65 70 75 80 85 90 95
East Mainland 50 55 60 65 70 75 80 85 90 95
Wind Gusts (mph) - 1st April - 31st October
S, SW, W & NW
Islands 50 55 60 65 70 75 80 85 90 95
West Mainland 50 55 60 65 70 75 80 85 90 95
East Mainland 50 55 60 65 70 75 80 85 90 95
N, NE, E & SE
Islands 50 55 60 65 70 75 80 85 90 95
West Mainland 50 55 60 65 70 75 80 85 90 95
East Mainland 50 55 60 65 70 75 80 85 90 95
Rainfall (mm)
12 hr (days 1 and 2) 24 hr (days 3 to 5)
>75 >100
>50 >50
<=50 <=50
Snowfall (cm)
12 hr (days 1 and 2) 24 hr (days 3 to 5)
if 24hr total >=10 >=5 >=10
>1 >=5
<=1 <5
if 24hr total >=5 >1
<=1
if 24hr total <5 any amount
Line icing
12 hr (days 1 and 2) 24 hr (days 3 to 5)
Severe Severe
other 12hr > Nil Moderate Moderate
other 12hr = Nil Moderate Slight
Slight Nil
Nil
Lightning risk and disruption colour code matrix

7. Islands Shetland; Orkney & NE Caithness; Western Isles; Cent. Highlands
West Mainland NW Highlands & Skye; Argyll & West
East Mainland Moray Firth; Aberdeenshire; Perth & Angus
Risk level 1 A B C D
Risk level 2 A B C D
Risk level 3 A B C D
Risk level 4 A B C D
Lightning Risk Categories
1 - Lightning will almost certainly occur across the region, or is occurring
2 - Lightning is likely across the region
3 - Lightning is unlikely across the region, although convective activity or an active front is forecast
4 - Lightning is not expected to occur across the region
Lightning Intensity Index
A - Very frequent lightning strikes
B - Frequent lightning strikes
C - Infrequent lightning strikes
D - Very infrequent lightning strikes
All Temperatures in °C
All Wind speeds in MPH