Monday 30 July 2012

Cold-front, low and possible snow 31 July 2012 - 01 August 2012


The latest model runs (GFS and NOGAPS up to 00Z on Sun 29th) have wobbled slightly, but continue to show modest amounts of rain, together with extremely cold upper air, over the southern Cape on Tues 31st and Wed 1st.

Strong winds are possible in places along the Eastern Cape coast on Wed 1st, as the low intensifies and pressure gradients are enhanced by the following high pressure cell.

The site snow-forecast.com shows the freezing level below 1200m along many of the coastal mountain ranges, with widespread (but light) snow likely, though not reaching as far as the Drakensberg: www.snow-forecast.com/maps/dynamic/southafrica


Edit: Due to problems with the NCEP custom GFS server, the only freezing-level charts currently available for this event are those on the snow-forecast.com site. For interest I am posting the GFS chart of the 850 hPa temperature (1500m elevation) at 06Z on Wed 1st, which shows the very cold air over the southern Cape coast, and parts of the interior of SA:


Compiled by Gordon Richardson - Stormchasing SA

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