missourian, the information which I referenced above came from a few different sources. The story regarding the lightning storm was from the journal of Pvt. Edwin Hart Robinson (1845 - 1932), "H" Troop, 2nd Regiment Alabama Cavalry, which currently belongs to a private collector. In his journal Pvt. Robinson is recanting the death of 1st Lt. Nick W. Lovell, "C" Troop, 2nd Regiment Alabama Cavalry who was killed by lightning on 28 Apr 1863 near Okolona, Ms. This after he and a few of the captains of other troops were coming in from a long scout when the storm suddenly overtook them and they ran for cover. The remains of 1st Lt. Nick W. Lovell were returned home to Tuscaloosa, Alabama where he was laid to rest at Evergreen Cemetery. Pvt. Robinson was not only a witness but also one of the victims, both he and his horse were also struck, knocking them both to the ground for several minutes before getting back to their feet.
Regarding the thunderstorms which arose while the men were on guard, picket and vidette duty, the rubber blanket, the extreme flooding around camp, and the men sleeping in their saddles on long scouts, that came from numerous letters written home by Pvt. Hardin P. Cochrane, "D" Troop, 2nd Regiment Alabama Cavalry, who later became the Sgt. Major of the regiment. He has some very fascinating letters which are beyond informative, in revealing much of the fighting, as well as camp life and oddities that he took note of around camp; such as men committing suicide, trees literally blowing up as they would be struck by lightning, flooding in camp, holding raffles at camp after being paid, deafening loud lightning strikes hitting things in and around camp, horses snoring while laying down and so much more. His letters are archived with the Alabama Department of History and Archives at Montgomery. But you will have to travel there to see the collection in person.
Other information came from letter`s written home by, Pvt. Samuel D. Cameron, "D" Troop and Pvt. Robert Wardroper, "B" Troop, 2nd Regiment Alabama Cavalry which are also at the Alabama Department of History and Archives. Other information came from the memoirs and journal of Brig. General Samuel Wragg Ferguson, under whom the 2nd Regiment Alabama Cavalry was assigned as part of his cavalry brigade from 27 Aug 1863 - 5 May 1865. He reveals a lot of information about how cavalry patrols, scouts, skirmishing, fighting and other aspects of the war affected his cavalry brigade, as well as them being kept out in inclement weather and torrential downpours for days on end, where they would suddenly be caught in violent thunderstorms, sleeping on fence rails in the middle of the road, losing upwards of 300 horses with lung fever contracted on a long treacherous march in west Tennessee, with some of his men dying from pneumonia after pushing them too hard in the cold winter weather, the horses feet becoming balled from riding them in the snow for too long, having to pull Troopers off of their horses half frozen because the rain which penetrated and froze on their cotton clothing had turned to ice in the high winds and below freezing temperatures, while almost freezing them in the process with numbed hands so bad that his men could not fight nor load their weapons, with many getting frostbite in their fingers and toes as a result... and so much more. The Mississippi Department of History and Archives have his collection, which can be visited at Jackson, Ms. Some are also digitized at a few of the larger and more prominent Universities where you can browse them if you can not make it to Jackson.
Pvt. Hardin P. Cochrane, wrote a three page letter home on 21 Jul 1862, from Bluff Springs, Florida in the Panhandle, where he wrote at length about a terrifying thunder and lightning storm and the damage for which it was responsible, that resulted in men and horses being killed in and around camp, noting how the lightning was selective and would almost pick and choose which would be its victims out of a group of men sleeping in a tent very close to one another, with the lightning only entering certain ones and leaving the others uninjured. And in some cases leaving one and entering dozens more in the immediate vicinity where numerous were killed or severely injured. As soon as I transcribe it I will post it here for you to read. It is very interesting.