What to do when one wears the cutest new dress to work, leaves one's umbrella in the car and attempts to leave said workplace during a torrential downpour / lightening storm:
1) Find large black garbage bag, preferably unused. Often located at the bottom of garbage cans (under the existing bag).
2) Cut and/or rip holes for head and arms. Cut smaller openings than you estimate to ensure tight fit and minimal leakage. Ensure arm holes are far away from the natural bag opening (i.e. near the neck hole).
3) Place bag over body and insert head/arms through previously created holes. Chuckle silently when realizing bag is precisely same length as cute new dress.
4) Make friendly conversation to smokers at exit. Disregard cautionary advice with respect to lightening overhead.
5) Run five blocks to vehicle. Since you are already soaked, feel free to jump in every puddle and/or flooded sidewalk along your route.
6) Smile. You made it! (Even if you are just as wet and slightly foolish looking.)
Nicely done!