Warnings:

For a forecast request, enter:

- Name & email address

- Request (event, location, date and time of required forecast)

Ex: Paddle boat,  Loch Lomond, Sunday 15th June 15:00. 

Grampian Weather Club

The place for weather information in the Grampian region

(courtesy of www.meteociel.fr)

(courtesy of www.theweathernetwork.com)

Only useable during hours of daylight

(courtesy of www.sat24.com)

(courtesy of www.time.unitarium.com)

 

Friday 04/09/15:

Synoptic situation at 1pm:

Low pressure in the S'ern N sea, high pressure W of Ireland with a rather tigh pressure gradient. Cold front across N'ern Scotland.

 

Weather:

 

 

24h precip accumulation: .

 

Winds:

Gentle to moderate NW'ly breeze, fresh to strong in the E. Increasing intensity through the day with gales possible in the NE in afternoon and evening.

 

Temperatures:

Max: 12 to 14 degrees.

Overnight min: 7 to 11 degrees, mildest along coasts.

 

Saturday 05/09/15:

Synoptic situation at 1pm:

High pressure W of Ireland exerting influence over the country. Weakening warm front to the NW. Rather tight pressure gradient especially in the E.

 

Weather:

24h precip accumulation: Close to nil.

 

Winds:

Moderate to fresh NW'ly breeze, strong in the E. Gales possible in the NE. Easing a touch later.

 

Temperatures:

Max: 10 to 12 degrees.

Overnight min: 9 to 11 degrees.

 

Sunday 06/09/15:

Synoptic situation at 1pm:

High pressure W of Ireland exerting influence over the country.  Slacker pressure gradient.

 

Weather:

 

 

24h precip accumulation: .

 

Winds:

Moderate to fresh NW'ly breeze, strong in the E. Gales possible in the NE.

 

Temperatures:

Max: 13 to 16 degrees, milder in the SE.

Overnight min: 8 to 12 degrees, mildest in the NE.

Jet stream: Fast river of air in the upper troposphere (approx. 10 km height) circumnavigating the globe. It is created by temperature differences between the Equator and the Poles. Coriolis Force from Earth rotation shifts the wind flow in a roughly West to East direction. Jet streams divide colder air to the North and warmer air to the South.

 

Jet streak: Localised regions of very fast winds embedded within the jet stream. It can reach speeds in excess of 200 mph. As air enters a jet streak, it speeds up. When it leaves a jet streak, it slows down. Accelerations and decelerations cause an imbalance of forces which, in turn, create descending and ascending motions. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rising motion, leading to storm intensification, occurs at the right entrance and left exit of the jet streak.

 

How it influences weather: Surface low pressure systems follow the path of maximum height fall (pressure drop) created by the vacuum effect of the rising motion (upper divergence).

 

How to use the map:

- Place your mouse pointer on the numbers at the top. They indicate hours in the future from the base time (red rectactangle).

- Locate jet streaks (the faster, the better) and identify right entrance and left exit.

- See if they interact with surface low pressure systems. Imagine the analogy of a rider (surface low) catching a wave (jet streak).

 

For a more detailed explanation on how low pressure systems deepen, click button:

Right Entrance

Left Exit

(courtesy of www.aurorawatch.lancs.ac.uk)

Greenwich Meridian Time (h)

Graph legend:

- black line: H-component (towards mag. N) of magnetic field

- blue line: typical quiet day

- bars: difference between the current field and a quiet day

 

Bar colours legend:

 

Green: No significant activity

Aurora is unlikey to be seen from anywhere in the UK.

 

Yellow: Minor geomagnetic activity

Aurora is unlikely to be visible from the UK except perhaps the extreme north of Scotland.

 

Amber (Amber alert): Possible aurora

Aurora is likely to be visible from Scotland, northern England and Northern Ireland.

 

Red (Red alert): Aurora likely

It is likely that aurora will be visible from everywhere in the UK.

Copyright (C) French Scot Pilot Weather 2017

 

"The weather as forecasted"