Well, aren't we the brave little traveler, stepping up to the whimsical adventure that is a flight with Allegiant Airline? Starting off in the delightful world of Baltimore, you're aiming to journey across the country to the palm-tree-lined paradise of San Diego. Cute!

Fortuitously, you have chosen Allegiant, the airline that's surely been vying for your attention with tantalizingly low-cost tickets. Who cares about added fees for luggage, seat selection, and onboard munchies when you're saving so much upfront, right?

Let's embark on the who of your travel. You, dear daredevil, have chosen to fly with the airline equivalent of a thrift shop. And why not? You don't need frills when you're in the friendly skies. Like a true pioneer, you understand the value of savings over fleeting comfort.

Moving to the 'what,' Allegiant Airline – a true gem in the rough. Built for the budget-conscious, Allegiant does not woo with luxuries but instead, focuses on getting you from A to B. No more, no less. It’s the Crock-Pot of air travel: slow, minimal and dependable.

Now, when are you departing? Because timing is a delicious game of roulette with this airline. Schedules change with the ebb and flow of the tide, the shift of the winds, maybe even the phases of the moon. You never know, and isn't that part of the fun?

The 'where' is your departure point of Baltimore, a city that's been eagerly preparing for your departure. Next stop: San Diego International Airport, the sun-kissed destination that patiently awaits your arrival. And no worries about transit once you land - San Diego has top-notch public transportation that will efficiently whisk you away to the city center or wherever your heart desires.

Finally, let’s unravel the ‘why.’ Why, indeed, would you embark on this journey from Baltimore to San Diego on Allegiant Airline? Because it’s cost-effective? Definitely! Because it’s a thrilling test of patience? Possibly! But most importantly, because it’s an experience? Absolutely!

Let's throw in the 'how' as a bonus feature. Relying on the principle of ‘you get what you pay for,’ Allegiant would never provide a boring, predictable travel experience. Instead, we embrace the unknown, the unforeseen, and the last-minute changes that make a simple flight an adventure.

In conclusion (and yes, we've made it through without any serious detours), your upcoming Allegiant flight from Baltimore to San Diego offers a unique experience that strays from the beaten path of pampered air travel. You may not have the luxury of a complimentary snack delivered by a smiling stewardess, but hey, you didn't pick Allegiant for the caviar. Safe travels, daredevil. We’re rooting for you!