God's absolute control over the forces of nature often reveals itself through sudden shifts in the weather. These abrupt changes show how the standard laws of nature are entirely subject to His oversight.
The primary approach among commentators is that even on a completely clear day, when the air is clean and there is no sign of rain, God can suddenly burden a cloud with a heavy load of water. This rapid shift from clear skies to heavy cloud cover is not a normal natural process, but rather a direct display of divine intervention [אלשיך, מצודת דוד]. Alternatively, this sudden gathering of clouds occurs specifically when the earth is thirsty and in desperate need of saturation [תקות אנוש, אבן עזרא]. A completely different perspective suggests that the burdening of the clouds is carried out by a specific angel appointed over rain and weather [רש"י, מצודת דוד]. Others explain that the heavy load placed on the cloud is actually thick snow or bright hail, which becomes so heavy that the cloud struggles to carry it [מלבי"ם]. Conversely, the burden might refer to a cloud that forms and then disappears without producing any rain, making its brief existence a useless effort [רלב"ג].
Following the formation of the heavy cloud, the next phase involves an act of spreading or scattering. One group of commentators explains that the cloud scatters its rain or snow across the earth, with the resulting downpour viewed directly as God's rain [רש"י, שטיינזלץ, מלבי"ם]. In contrast, others explain that God actually scatters and removes the cloud itself in order to reveal the sunlight once more. Just as He can gather storm clouds in an instant, He can disperse them in the blink of an eye, withholding the rain to inspire wonder and display His power [אלשיך, תקות אנוש]. Another interesting angle suggests a simultaneous event, where the cloud releases its rain at the exact moment the sun is shining brightly [אבן עזרא].