Thu, 02 Apr 2015
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 25/16
ALLDAYS 27/17
BEAUFORT WEST 28/15
BELA-BELA 28/17
BETHLEHEM 24/13
BISHO 25/16
BLOEMFONTEIN 27/14
CALVINIA 28/18
CAPE ST LUCIA 86/90
CAPE TOWN 20/15
CLANWILLIAM 31/18
DE AAR 27/16
DURBAN 27/18
EAST LONDON 24/18
ERMELO 24/11
FAURESMITH 27/16
FICKSBURG 24/11
GEORGE 18/15
GRAAF-REINETT 26/15
GRAHAMSTOWN 25/15
HERMANUS 19/14
JOHANNESBURG 25/13
JOUBERTINA 20/14
KIMBERLEY 27/16
KLERKSDORP 27/15
KOMATIPOORT 31/18
KROONSTAD 25/14
LADYSMITH 28/16
LANGEBAAN 21/15
LEPHALALE 29/17
LYDENBURG 24/14
MAFIKENG 26/14
MUSINA 27/17
NELSPRUIT 24/14
NEWCASTLE 28/14
OUDTSHOORN 25/14
PAARL 25/14
PHALABORWA 29/18
PIETERMARITZBURG 27/16
PLETTENBERG BAY 19/17
POLOKWANE 26/14
PORT ALFRED 22/18
PORT ELIZABETH 21/17
PORT ST JOHNS 25/21
POTCHEFSTROOM 26/16
PRETORIA 27/16
QUEENSTOWN 28/15
RICHARDS BAY 29/20
ROBERTSON 21/12
RUSTENBURG 27/18
SASOLBURG 26/15
SKUKUZA 30/17
SOWETO 25/14
SPRINGBOK 26/13
STILBAAI 19/16
SUTHERLAND 24/14
TZANEEN 23/16
ULUNDI 28/15
UMTATA 26/15
UPINGTON 25/19
VEREENIGING 26/15
VREDENDAL 20/13
VRYBURG 29/17
WELKOM 27/15
WITBANK 24/12
WORCESTER 23/12

 

| 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