Here is a rough guideline to different weather types and the warnings associated with them.

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 winter time. In summer there are many more people 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.
Trees being in full leaf are a lot more susceptible to high winds and heavy rain, so we also equate this into the warnings.

The images below are samples from each category of severity.

ALERTS 

Alerts are only issued for extremes of temperature.
When the temperature is expected to be higher than 30’c during the day and/or not fall below 20’c at night.
When the temperature is expected to remain below 3’c during the daytime and/or the mean temperature is below 0’c for more than 24 hours.
A frost alert will be issued if the temperature is likely to fall below 3’c at any time of the year.

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 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: Frost, Ice/Black Ice, Snow, Fog, Large Waves, Storm Surge, Flooding, Heavy Rainfall, Thunderstorms, Squalls, High Winds reaching 45-55mph between 1st May and 30th September, and 60-65mph from 1st October until the 30th April.

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.

WEATHER WARNINGS
A Severe Weather Warning will be issued if severe weather is likely within 72 hours and under exceptional circumstances 96 hours.

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, High Winds reaching 55-70mph between 1st May and 30th September, and 65-75mph  from 1st October until the 30th April.

AMBER WARNING means A higher likelihood of disruptions and damage could occur than with Yellow Warning along a more widespread risk.
The risk of accident or injury due to the weather is significantly heightened with a potential risk to life. There is also a significant risk of travel disruptions as well as possible power cuts.
Weather types include: Storm Surge, Flooding, Heavy Rainfall, Thunderstorms, Snow, Ice or Black Ice, Freezing Rain, High Winds reaching up to 70-85mph between 1st May and 30th September, and 75-85mph from 1st October until the 30th April.

RED WARNING means that very dangerous conditions are expected with a significant risk of accident or injury as well as risk 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 disruptions are also very likely.
Weather types include: Flooding, Extreme Rainfall, Extreme Snowfall, Freezing Rain, High Winds of 85mph or higher

Planning ahead could potentially save lives, so make a safety plan if severe weather is expected.