Now, as to the term 'storm window'...it was coined by a small airplane pilot long ago, who needed to land in a severe rain storm, where visibility was totally obscrued out the front
I don't know about a small aeroplane pilot inventing the term but I do know we called them storm windows on the Dakota and Lincolns I flew in the early Fifties. They were mainly there if ice obscured the main windows and in fact it was a normal design feature of old British aircraft and some American types as well. Circling in blinding rain when the wipers simply could not cope, it was SOP to open the storm window to improve forward vision and it was very effective although a trifle noisy with four RR Merlins on the wings.
The sliding cockpit windows installed on the 737 can also be used in the open position for not only smoke egress but if you have to land and vis is severely restricted through the forward screens. The wipers on the 737 are inefficient in blinding rain and if the chips are really down it may be the only way to get the aircraft on the ground by peering through the open window. The FCTM covers this.