The latest GFS model run (18z, 27 May 2009) is showing slightly less rainfall than previous runs for the Western Cape, though larger amounts for the southern coastal areas of the Eastern Cape. The main aspects continue to be that of the extremely cold temperatures likely to be felt over the weekend. Temperatures through out the Western Cape are to remain below 15 degrees on Friday with snowfalls likely over the higher mountain ranges through Friday and early on Saturday.
Strong winds of up to 65km/h are still forecast to occur in places between Cape Agulhas to Plettenberg Bay. Though winds are likely to remain around 40-50km/h around the Mother City. Rainfall totals near the mountains could exceed 50mm in a period of 24 hours with likely heavier falls on the higher mountain regions of the Western Cape. Rough seas with swells in excess of 5 meters along the Cape coast as well as very strong winds and rough seas off shore as the low pressure intensifies to the south of the country.
For more updated information on this weather system be sure to pay the forums a visit.
Recent model guidence has been indicating another possible stormy weekend ahead for the Western Cape and Eastern Cape with temperatures remaining below 10`C for some areas of the Eastern Cape on Sunday. It appears that while the Eastern Cape may feel the brunt of the cold the most, the Western Cape will be in for heavier rainfalls with the South African Weather Service forecasting over 100mm of rain in a four day period from Thursday to Sunday. While the models are still a bit back and fourth on this storm it definitely bears watching. Especially for those in parts of the Western, Northern and Eastern Cape.
The South African Weather Service has issued the following warnings
Very cold, wet and windy conditions are expected to set in over the high ground of the Western and Northern Cape Provinces on Friday, persisting through Saturday. Snowfalls are expected on the western high ground of the Western and Northern Cape Provinces on Friday, spreading to the eastern high ground of the Western Cape on Saturday. Gale force north-westerly to westerly winds are expected in places between Table Bay and Plettenberg Bay on Friday and Saturday.
Gordon Richardson made the following post regarding this storm system in the forums area.
"The synoptic chart at 00Z this morning (Tue 26th) shows a large frontal system approaching the Western Cape: www.weathersa.co.za/ship/ship.gif The initial low is fairly weak (central pressure 1002hPa), though this may intensify slightly.
High cloud associated with a weak upper trough is forecast to arrive from the subtropics early on Wed 27th, though this is not related to the main frontal system. www.weathersa.co.za/glider/glider2/images/h26.gif
The deep low behind the first front looks set to pass far to the south of Cape Town. Further fronts may develop in this system during the weekend."
Last Updated on Wednesday, 27 May 2009 21:58
21 May 2009 - Cape Town Thunderstorm
Thursday, 21 May 2009 13:07
Cape Town got an unexpected dose of thunderstorm activity on the 21 May 2009, when a trough which was situated along the West Coast seemed to close into a coastal low pressure around Cape Town. This caused some upper air instability which coupled with the moisture present was enough to produce some unforecast thundershowers. Activity began around 06:30am and continued till around noon, with the strongest storms occuring earlier- around 7am. The thunderstorms brought very little rain but gave a great lightning display as it passed over False Bay. Below are some images I managed to get of the storm in Somerset West, credits to the South African Weather Service for the radar image.
Timelapse Video
Last Updated on Saturday, 24 April 2010 19:41
First Invest of 2009 Atlantic Hurricane Season
Monday, 18 May 2009 21:53
UPDATE
Invest 90L has been deactivated due to the circulation being absorbed by another system. One should keep monitoring the waters around Florida over the next few days as the development of a second low looks quite possible.
The first invest of the 2009 Atlantic Hurricane Season was issued today, Monday 18th May 2009. The suspect area is situated to the north of Cuba, as can be expected with a system in the early stages there is little organization at present and convection remains fairly moderate. Model data over the past few days has continued to favour a solution of the low moving towards Florida and then depending on the model either going right up the coast or going left into the Gulf of Mexico.
Should this invest become a tropical depression it will come near 2 weeks before the official start of the 2009 Atlantic Hurricane Season which forecasters have suggest will have a low to average number of storms. Though the development of an early A-lettered would suggest otherwise. For those interested in severe weather tracking the Atlantic Hurricane Season can be a fun and exciting activity and a chance to witness history in the making.
"SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT AN AREA OF DISTURBED WEATHER HAS FORMED OVER EASTERN CUBA...THE SOUTHEASTERN BAHAMAS...AND THE ADJACENT WATERS. SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT DAY OR TWO AS IT MOVES GENERALLY NORTHWARD AT 10 TO 15 MPH.AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WILL INVESTIGATE THE SYSTEM ON TUESDAY...IF NECESSARY. THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS."
One is able to see they have scheduled a possible 'recon' mission, for those who are unaware what 'recon' does, is when there is a potential tropical system which has the potential to effect the United States, they will send out an aeroplane to get information about the developing or developed storm. This information can confirm the existence of a closed circulation and is often the make or break of defining a system as a tropical disturbance. These planes measure wind speed, direction, pressures and numerous other variables. They are also then added to the model runs which help in accurately forecast the trajectory of the system.
Image Credits : NRL Monterey
Last Updated on Tuesday, 19 May 2009 21:41
13 May 2009 Tornadoes - United States
Thursday, 14 May 2009 20:38
The Storm Prediction Center issued a moderate risk area for the states of MO, IN, IL and parts of OK. Early on the 13 May 2009 evening conditions became ripe for tornado development, especially in MO, where there were numerous tornado reports. Below are videos from the Kirksville, MO tornado which is believed to have killed 3 people.
Latest on Weekend Storm
Thursday, 14 May 2009 14:21
Latest model guidance is showing what could be a very rough ride for residents of both the Western Cape and areas of the Eastern Cape this coming weekend. Rainfall estimates have shot up for Saturday around Cape Town, Boland, Winelands and areas of the Overberg. Rainfall totals have the possibility to exceed 50mm in 24 hours in numerous parts of the Western Cape with Gale Force winds expected. Strong winds will also affect Mossel Bay on Sunday where 55km/h winds are forecast by the South African Weather Service. Extremely strong winds in excess of 75km/h is forecast by the SAWS to impact Cape Point. Again I urge everyone to keep an eye on this system as warnings should be put into place soon.
Advisory - FOR SATURDAY (16/05/2009) Heavy falls of rain (50mm) are possible in places near the western mountains of the Western Cape Province. Gale force north-westerly winds (70km/h) are expected in places over the Western Cape Province, spreading to the west coast of the Eastern Cape by evening. Very rough to high seas with total wave height exceeding 6 to 7m are expected between Orange River Mouth and Cape Agulhas, spreading Plettenberg Bay by overnight.
