Birders' Weather

Note for Weather Buffs - this is deliberately a simplified explanation.
It is not meant to be a thesis for a PhD

Many of us are lucky enough to have some flexibility over our birdwatching.  I try to make use of the most suitable weather windows.  For example, recently I could go birding on either the Wednesday or the Thursday.  By the previous Sunday, the forecast charts for the week indicated that the Wednesday would be a very cold, exness暗号 unpleasantly windy day.  However, a much calmer day could be expected on Thursday.  I went birding on Thursday.  It was a splendid, fine day. 

The fact that I couldn't find the reported Firecrest is a different story…….

But before you plan the week's activities, look at the Tides and Sunrise/Set tables

Also latest Charts and Satellite and Radar Images

Satpix and Radar   These are just examples
Latest Satpic

Satpic animation

Latest Radar

Radar animation


Weather Charts - how to interpret

Isobars (lines on weather charts) give many important clues. 
High Pressure or Anticyclone Usually means fine settled weather, with light winds. 
Not necessarily sunny, especially in winter.  Perhaps foggy inland at night and in morning.
Low Pressure or Depression.  Often means windy weather with periods rain or showers a distinct possibility.
Pressure Patterns.  In the very broadest terms, there is a semi permanent High in the region of the Azores, and a semi permanent Low in the Iceland area
Wind Direction and strength.  This is easy to work out from the isobars.
The wind blows clockwise round a High Pressure
  Rule of Thumb - Highs give good weather - the hands on the best clocks move clockwise
  Conversely, the wind blows anticlockwise round a Low - bad clock, bad weather!
Wind Strength.  The closer isobars are together, the stronger the wind
Curvature of the isobars.  All other factors being equal, (spacing of isobars, wind direction) anticyclonic curvature, gives better weather than cyclonic curvature.
Temperatures.  On this particular type of chart, the colour coding gives a rough indication of the expected temperatures.  (Weather buffs know that it is rather more subtle than this)

Here you can see the Low near Iceland and the High near Azores.
Remember the Rule of Thumb.
The winds blow clockwise round the Azores High, anticlockwise round the Iceland Low, so in that part of the North Atlantic, the winds are West or North West.  Over Iceland itself, they are Southerly. 
Near Iceland, the isobars are close together - it is windy there.  Near the Azores, it is less windy.  Over the British Isles, it is calm in England , but there is a moderate SW'ly in Scotland.  Temperatures near average for time of year.

Here's a good example when a "Southern Wimp" (quote Bill Alexander) wouldn't want to go birding.
(I might twitch a local Firecrest!)

The isobars are quite close, and have cyclonic curvature.  It will probably rain, especially in the West.  Although not particularly cold, it would not be the most pleasant of days.

But seawatchers are tough.  It might be ideal on West Coasts.

This day on the other hand, although the winds are similar, the isobars are anticyclonically curved in the South.   So at least there, the weather will be far more benign, with little likelihood of rain in the South. 
Western Scotland might still get showers.

Gentle to calm winds over England.  More windy and probably showery over Northern Ireland and Western Scotland.

General rain possible in 12 - 18 hours time - there is a trough (distinct cyclonic kink in the isobars) west of the British Isles.

And here we can see a chart for this same time from another source.  This one shows weather fronts.  In simple language, a front is a boundary between two different types of air.  For example when a cold front passes through, warm damp air might be replaced by cooler less humid air.

In this example, the warm and cold fronts, and the so called "occluded front" where they join together, are clearly shown.  Very often, fronts are associated with several hours of rain.  In the cooler air behind a cold front, there might well be sharp showers, but most probably not prolonged rain.

Many different charts and satellite pictures can be found on my Website
Forecast models are available from various sources, but in truth, none can be relied upon further than about six days ahead.  As good as any is MRF which is updated around 1100 hours in the morning.  Look at this Series of Charts and either STOP (then Reload) on the days that interest you, or go to the top of the page and download a single chart.  Those annotated with a  .5d , (such as 4.5d ) give the 1200 hours forecast chart (for 4 days time)

The charts with the fronts - as illustrated above are at this US Military Site
When you reach the website, use slider on left side of page to Weather  Briefs

Another good source of charts is ECMWF.  This gives midday forecast charts for the four days starting the day after tomorrow.  It is available from around 0600 hours.

And this is a very quick route to a midday chart for today giving rainfall

Five Day Forecasts - follow link when you reach BBC (top right of page)

Birders can make many other uses of weather charts.  A run of strong Westerlies across the Atlantic in Autumn should bring plenty of North American vagrants.  Easterlies or South Easterlies might well bring an East Coast Fall at the appropriate time of year.  Strong Autumn Northerlies often brings some interesting birds well inland in East Anglia. Warm Southerlies in late Spring could be dubbed "Hoopoe Weather".

For more non-technical weather information, try my Layman's Weather Page

Turn the weather to you advantage.  Enjoy the birding. 

The Webmaster accepts no liability for the accuracy of any information obtained from links to this website.  No liability can be accepted for decisions made by individuals on the information obtained from this site - it is an information site only.

Lowestoft Tides here
Hunstanton -2:30
Wells -3:35
Cromer -3:05
Gt.Yarmouth -0:35
Orford Ness +1:35
Harwich +2:20
Blk'water +3:05
Southend +3:05
corrections for other places in this table