Wed, 22 Feb 2017
METROCAST | 




SA REGIONAL




INFORMATION




You are in: Weather > SA regional > Ecucation


COASTAL LOWS

A coastal low is a shallow low pressure system limited to the lower layers of the atmosphere and is formed when the wind blows from the land TO the sea, usually during bergwinds. These coastal low pressure systems usually form off the Namibian or West Coast of SA. They then slowly move doen the coast and round the SW Cape and then move up the East Coast of SA where they finally fill up along the Mozambique coast where the plateau ceases to exist. Click on the minimised image below to view a larger diagram showing how the coastal low is formed.


Click to view a larger image.

Air moves off the coast at a height of approximately 1500m. This creates a relative "vacuum" at the surface as air rises to replace the air that is moving away from the coast. In a low pressure system, air rises clockwise in the southern hemisphere and the resultant circulation around the low pressure is the same. Hence, prior to the presence of a coastal low, the winds are usually offshore and in Cape Town they are usually in the form of hot, dry NE bergwinds. Once the coastal low moves through the area, the hot, dry winds are replaced by cool, moist NW-SW winds and usually fog. Coastal lows usually precede cold fronts in winter.


Click to view a larger image.

Click on the minimised image above to view a larger image showing the various synoptic features associated with a coastal low.

[ back ]

Search
Goodstuff



Goodstuff
ALEXANDER BAY 22/13
ALLDAYS 23/19
BEAUFORT WEST 37/13
BELA-BELA 27/16
BETHLEHEM 24/12
BISHO 30/15
BLOEMFONTEIN 28/15
CALVINIA 36/18
CAPE ST LUCIA 26/23
CAPE TOWN 28/15
CLANWILLIAM 37/19
DE AAR 32/17
DURBAN 24/17
EAST LONDON 23/18
ERMELO 19/13
FAURESMITH 32/16
FICKSBURG 25/12
GEORGE 25/14
GRAAF-REINETT 38/12
GRAHAMSTOWN 29/12
HERMANUS 28/15
JOHANNESBURG 20/14
JOUBERTINA 31/11
KIMBERLEY 33/19
KLERKSDORP 26/17
KOMATIPOORT 29/20
KROONSTAD 27/15
LADYSMITH 26/15
LANGEBAAN 24/16
LEPHALALE 28/18
LYDENBURG 24/16
MAFIKENG 25/16
MUSINA 25/20
NELSPRUIT 24/16
NEWCASTLE 25/14
OUDTSHOORN 38/14
PAARL 32/16
PHALABORWA 26/19
PIETERMARITZBURG 24/14
PLETTENBERG BAY 22/16
POLOKWANE 23/16
PORT ALFRED 25/17
PORT ELIZABETH 23/17
PORT ST JOHNS 25/18
POTCHEFSTROOM 24/17
PRETORIA 24/16
QUEENSTOWN 35/13
RICHARDS BAY 25/21
ROBERTSON 37/14
RUSTENBURG 26/17
SASOLBURG 21/14
SKUKUZA 28/21
SOWETO 20/13
SPRINGBOK 20/13
STILBAAI 25/17
SUTHERLAND 31/12
TZANEEN 21/16
ULUNDI 27/16
UMTATA 27/13
UPINGTON 37/24
VEREENIGING 21/15
VREDENDAL 31/13
VRYBURG 30/17
WELKOM 28/15
WITBANK 19/13
WORCESTER 36/15

 

| DISCLAIMER | FEEDBACK | ABOUT US | ADVERTISING | CONTACTS | SERVICES & PRODUCTS |

©COPYRIGHT 1995-2010, CUSTOMWEATHER,INC
San Francisco, California, USA
Your use of this site constitutes your acceptance of
the LEGAL RESTRICTIONS AND TERMS OF USE