Weather Warnings and Advisories
DETAILS
A squall line is likely to develop on Thursday morning which will show itself as a line of intense precipitation along with extremely squally and gusty winds.
The strongest winds are likely to be fairly localised and short lived, associated with what will be small areas of intense rainfall within a band of more generalised rainfall, although may also be accompanied by hail and perhaps even the risk of a rumble of thunder.
Wind gusts on exposed coasts and headlands could briefly reach 70-80mph and closer to 60-70mph elsewhere.
Tornadoes and waterspouts are also a possibility, especially over the sea, however this is not a "tornado warning", but is just highlighting the possibility.
It should be noted that the worst conditions will last for no more than an hour and it is rather difficult to pinpoint the exact time of its passage (models currently suggest midday-1pm), with fairly strong winds of 50-60mph on the run-up to the squall which is below our warning threshold.
POSSIBLE IMPACTS, EFFECTS AND MEASURES
• Dangerous driving conditions for a short time, especially on exposed roads in the south and west as well as the more elevated island routes.
• Spray and surface water leading to poor visibility at times, especially over the more exposed and elevated routes
• Falling tree debris such as leaves, twigs, perhaps even a few branches and the odd downed tree
• Risk of structural damage to buildings and property
• Hazardous to watercraft due to sudden and rather unexpected deterioration of the conditions
• Delays and cancellation to public transport are likely, especially cross Solent travel
WEATHER TYPE: Squall
TIME AND DATE ISSUED: 11:00 on Wednesday, January 22nd
VALID FROM: 11:00 until 14:00 on Thursday, January 23rd
DETAILS
A spell of strong south to southwesterly winds will affect the island during Friday morning with gusts of 70-75mph possible in the more exposed parts of the south and west and over high ground and 50-60mph elsewhere. Spells of heavy and persistent rain are likely to affect the island during the same period leading to additional hazards with 15-20mm likely to fall rather widely but as much as 30mm in a few locations.
POSSIBLE IMPACTS, EFFECTS AND MEASURES
• Dangerous driving conditions, especially on exposed roads in the south and west as well as the more elevated island routes.
• Spray and surface water leading to poor visibility at times, especially over the more exposed and elevated routes
• Falling tree debris such as leaves, twigs, perhaps even a few branches and the odd downed tree
• Risk of structural damage to buildings and property
• Very large waves around western and southern coasts although no coastal/tidal flooding is expected but we are expecting "surges" of water on western and southern beaches due to the size of the swell
• Delays and cancellation to public transport are likely, especially cross Solent travel
WEATHER TYPE: Severe Gales and Heavy Rain
TIME AND DATE ISSUED: 09:00 on Tuesday, January 21st
VALID FROM: 05:00 until 16:00 on Friday, January 24th
EARLY WEATHER WARNINGS/WATCHES
An early warning or watch will be issued if the risk of severe weather is either very uncertain or is more than 72 hours ahead. Weather types can include: High Winds, Heavy Rainfall and Snow.
ADVISORIES
These are issued for very limited or extremely localised severe weather. The conditions may still cause a few disruptions to outdoor events and activities as well as a few travel disruptions or delays.
We also issue advisories for very cold temperatures: In winter when the average temperature is expected to remain below 3°C for a period of 36 hours or longer. A frost alert will be issued if the temperature is likely to fall below 3°C at any time of the year, but will be covered by our regularly updated frost maps.
We also issue separate Large Wave Advisories for Eastern and Southern parts of the island during the summer months if the swell is likely to be in excess of 2 meters.
Other weather types can include: Ice/Black Ice, Snow, Fog, Large Waves, Storm Surge, Flooding, Heavy Rainfall, Thunderstorms, Squalls and Frequent Wind Gusts reaching 45-55mph between 1st April and 30th September, although we do not issue wind advisories outside of these times.
YELLOW WARNING means there is a risk of disruption to everyday activities such as outdoor leisure activities as well as the potential for some travel disruptions. There may be some property damage depending on the weather type and there may also be a risk of accident or injury due to the weather if you are spending time outdoors.
Weather types include: Large Waves, Storm Surge, Flooding, Heavy Rainfall, Thunderstorms, Snow, Ice or Black Ice, Freezing Rain, Fog, Squalls and Frequent Wind Gusts reaching 55-70mph between 1st April and 30th September, or 65-75mph from 1st October until the 31st of March.
AMBER WARNING means A higher likelihood of disruptions and damage could occur than with Yellow Warning along with a more widespread risk. The risk of accident or injury due to the weather is significantly heightened with potential danger to life. There is also a significant risk of travel disruption as well as possible power cuts.
Weather types include: Storm Surge, Flooding, Heavy Rainfall, Thunderstorms, Snow, Ice or Black Ice, Freezing Rain and Frequent Wind Gusts reaching up to 70-85mph between 1st April and 30th September, or 75-85mph from 1st October until the 31st of March
RED WARNING means that very dangerous conditions are expected with a significant risk of accident or injury as well as danger to life and property. It is advisable to take the correct action to protect yourself and others from the severe conditions, and if possible to follow advice given on national and local broadcasts. Power cuts and severe travel disruption is also very likely.
Weather types include: Flooding, Extreme Rainfall, Extreme Snowfall, Blizzards, Freezing Rain and Frequent Wind Gusts of 85mph or higher
Planning ahead could potentially save lives, so make a safety plan if severe weather is expected and follow local and national updates on television, radio and online.
ABOUT OUR WARNINGS
There are many variables that come with each warning and we take into account the time of year, the time of day and also the conditions running up to the severe weather event. Summer warnings tend to be issued under slightly less severe weather than in wintertime as there are many visitors on the IOW along with a dramatically increased amount of people outdoors enjoying various activities and inevitably a larger amount of people driving on the islands roads, so here is a rough guideline to different weather types and the warnings associated with them.
WEATHER WARNINGS
A Severe Weather Warning will be issued if severe weather is likely within 72 hours and under exceptional circumstances 96 hours.