Sat, 13 Feb 2016
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 24/16
ALLDAYS 37/24
BEAUFORT WEST 29/14
BELA-BELA 35/21
BETHLEHEM 30/16
BISHO 27/17
BLOEMFONTEIN 34/20
CALVINIA 24/10
CAPE ST LUCIA 31/23
CAPE TOWN 24/17
CLANWILLIAM 26/16
DE AAR 34/17
DURBAN 30/22
EAST LONDON 24/20
ERMELO 29/15
FAURESMITH 34/19
FICKSBURG 30/18
GEORGE 21/17
GRAAF-REINETT 29/14
GRAHAMSTOWN 25/16
HERMANUS 22/15
JOHANNESBURG 31/17
JOUBERTINA 23/13
KIMBERLEY 36/19
KLERKSDORP 33/20
KOMATIPOORT 35/21
KROONSTAD 34/19
LADYSMITH 35/18
LANGEBAAN 22/15
LEPHALALE 36/25
LYDENBURG 32/18
MAFIKENG 34/22
MUSINA 38/24
NELSPRUIT 30/16
NEWCASTLE 35/18
OUDTSHOORN 29/16
PAARL 22/14
PHALABORWA 36/21
PIETERMARITZBURG 34/18
PLETTENBERG BAY 22/18
POLOKWANE 32/19
PORT ALFRED 24/18
PORT ELIZABETH 24/19
PORT ST JOHNS 27/22
POTCHEFSTROOM 32/19
PRETORIA 33/20
QUEENSTOWN 29/13
RICHARDS BAY 32/22
ROBERTSON 25/14
RUSTENBURG 35/21
SASOLBURG 31/17
SKUKUZA 36/21
SOWETO 31/17
SPRINGBOK 31/18
STILBAAI 26/17
SUTHERLAND 23/10
TZANEEN 32/18
ULUNDI 36/18
UMTATA 27/16
UPINGTON 34/19
VEREENIGING 33/17
VREDENDAL 23/14
VRYBURG 36/19
WELKOM 34/21
WITBANK 31/15
WORCESTER 24/15

 

| 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