for Weather Buffs - this is deliberately a simplified explanation.
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 Radar These are just examples
Charts - how to interpret
(lines on weather charts) give many important clues.
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.
Pressure or Depression. Often means windy weather with
periods rain or showers a distinct possibility.
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
Direction and strength. This is easy to work out from
The wind blows clockwise
round a High Pressure
of Thumb - Highs give
weather - the hands on the best clocks
Conversely, the wind
blows anticlockwise round a Low - bad clock, bad weather!
Strength. The closer isobars
are together, the stronger the wind
of the isobars. All other factors being equal, (spacing
of isobars, wind direction) anticyclonic curvature,
gives better weather than cyclonic
On this particular type of chart, www.exness-trade.jp.net
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
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.
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.
a good example when a "Southern Wimp" (quote Bill Alexander) wouldn't
want to go birding.
(I might twitch a local
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
|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 ,
4.5d ) give the 1200
hours forecast chart (for 4 days time)
The charts with the fronts
- as illustrated above http://exness-trade.jp.net/
are at this US
When you reach the website,
use slider on left side of page to
Another good source of charts
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
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
Turn the weather to you advantage. Enjoy the birding.
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.
corrections for other places
in this table