Teams looked into relocating this week's Jerez testing to another circuit.
After rain disturbed the running at the southern Spanish venue last week, the weather forecast for this week at Jerez is even worse.
Heavy and constant rain could affect all four days of the test, which prior to March's Bahrain opener will be followed by just four more days of pre-season testing at Barcelona.
The Swiss newspaper Blick reports that investigations about relocating the scheduled Jerez running to Valencia or Portimao bore no fruit.
"The (alternative) circuits are busy," said Sauber team manager Beat Zehnder. "And the weather is too uncertain."