Service summary
Contents
Service details
Warning of severe weather facing the UK. This service details
extremes of weather, which will effect the UK. It is issued as
and when necessary.
| Warning: The UK national and regional forecast datafeed
services are products produced by the Public Weather Service
(PWS). Although this service is permitted to be delivered to
commercial users for use on their web sites and intranet sites,
you should be aware that the Public Weather Service could change
aspects of the service, including the format, delivery times
and content. We will try to notify you as soon as possible
of any changes, but it is the service delivery mechanism that
you are paying for and not the actual content. |
Summary of service
details
- Text format
- Updated as and when required
The UK severe weather warning forecast service gives notification
of extreme weather based upon Local and Unitary Authority areas.
This service is provided as and when required and will be sent
out automatically via FTP.
About the writing
of the script
1. Meteorological Criteria for the issue of Warnings
The overriding criterion for the issue of warnings is the strong
likelihood of severe weather which may cause considerable inconvenience
to a large number of people and/or present a danger to life.
The conditions set out below give guidance concerning the severity
of the weather likely to meet these criteria.
Flash warnings are issued whenever there is a strong likelihood
of severe weather conditions occurring over an area.
| Warning |
Conditions |
Flash warnings of severe weather |
Flash warnings are issued whenever there is a strong likelihood
of severe weather conditions occurring over an area:
- Severe gales - Repeated gusts of 70 m.p.h. or more over
inland areas
- Storms - Repeated gusts of 80 m.p.h. or more over
inland areas
- Heavy snow - Snow falling at a rate of
approx. 2 cm/hour or more expected for at least two hours
- Very heavy snow - Snow falling at a rate of approx.
2 cm/hour or more expected for at least two hours, accumulating
to 15 cm or more
- Blizzard - Moderate or heavy snow accompanied
by winds of 30 m.p.h. or more with visibility reduced to
200m or less, or drifting snow giving rise to similar conditions
- Severe blizzard – Heavy snow
accompanied by winds of 30 m.p.h. or more reducing visibility to
near zero
- Heavy rain - Rain expected to continue for at least
two hours and to give at least 15 mm within a 3-hour period
or, following previous heavy rain events, 25mm/day. Warnings
may be triggered by thunderstorms (warning will state this
if expected)
- Fog - Visibility below 50 metres
(restricted to heights where major roads occur)
- Widespread
icy roads, glazed frost, freezing rain - When rain
falls onto surfaces with temperatures at or below zero;
or condensation occurs on surfaces at or below zero; or
already wet surfaces fall to or below zero. The ice is
usually clear and difficult to distinguish from a wet surface.
It usually forms ion sheets. Warnings are issued when any
depth of ice is expected over a widespread area. generally
occur when rain freezes on contact with road surfaces
- Heatwave (NHS Heat-Health Watch) - Expectation
of significantly higher than average temperatures in one
or more regions of England and Wales; thresholds are pre-determined
regionally via the Heat-Health Watch system
|
2. Content
a. Units
- All references to time will be local clock time, either
summer or winter, but no reference will be made to BST, UTC.
- Wind speeds will be expressed in miles per hour (m.p.h.).
- Rainfall amounts will be expressed in millimetres.
- Snow depths
will be expressed in centimetres.
- Visibility will be expressed
in metres.
- Heights will be expressed in metres.
b. The use of probabilities
- The percentage probability of an event occurring may be used
if it is felt appropriate.
c. Terminology
- Warnings are worded to give the best advice to the public as
to the effects of the weather on them.
d. Example Warning
NATIONAL SEVERE WEATHER WARNING SERVICE
Flash Warning of
- Widespread Dense Fog
For the following areas
- Lincolnshire
Widespread areas of dense fog will reduce the visibility to
50
metres or less in places. The public are advised to take extra
care
and refer to the 'Highways Agency' for further advice on traffic
disruption on motorways and trunk roads.
Issued by the Met Office at 07:11 on Wednesday, 28th March 2007
Valid from 07:11 on Wednesday, 28th March 2007
until 09:00 on Wednesday, 28th March 2007
For enquiries regarding this warning -
please contact the Met Office customer centre
- Phone: 0870 900 0100
- Fax : 0870 900 5050
- Email: enquiries@metoffice.gov.uk
Pricing
The UK severe weather warning forecast service assumes a one-year
contract. Prices are based purely on the basis of service provision
(not the content) and the basic graphics package and does not include
technical support. The price for the service provision is £515 +
VAT per annum.
Standard terms and
conditions
All Met Office Services are subject to our standard terms and conditions,
which can be faxed to you upon request and will be automatically
dispatched with the contract.
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