It is highly unlikely the property/lot own has any liability:1) You write that the post was "camoflagued"--however, even if it was not painted yellow but was painted silver (as you seem to indicate), it is hardly "camoflagued" or hidden--it's a visible post. The law does not require a property to take unusual or exceptional measures to make posts visible; and conversely, a driver is expected to exercise reasonable diligence or care in driving and avoid visible hazards.2) The owner is clearly not responsible for any impairment of visibility due to the rain.