My two cents: Your 'disasters' are in part seasonal. You know you'll have a blizzard somewhere along in spring, as you're in the path of both the eastward cold fronts and the northward warm fronts. Plan on being stranded in your car, at work, and at home, and you'll be set for that. You may also have hurricane remnants sweeping into Southeastern Pennsylvania during the late summers. Plan on being stranded in your car, at work, and at home. However, the dangers from the two strandings are very different. Cold vs. flood waters.

Most people do not live in areas where terrorism is, in my very humble opinion, a legitimate concern. You, however, do work in the District. I would have a bag with me at the times I'm in Washington that would have water, glowsticks, leather gloves, dust masks, a couple or three FRS radios, a few dollars in quarters for payphones, a bandana, and such other items as I could comfortably carry over my shoulder where ever I go. (I recommend the same thing in the San Francisco Bay Area which is earthquake country.)

Blizzards come when the forecast is for rain, so you have no time to prepare for that. Hurricanes come with plenty of warning, but sometimes veer off the predicted course, so you may have no time to prepare. So I'd be ready to shelter at home. In your area, winters are generally not severe, but I'd be prepared for at least a week without power during a very cold winter. If trees are down, you may not be able to leave for some period of time; if the snow was deep, it may sit there a few days; if it ices over, roads may not be driveable. Etc.

If you can't get out before a hurricane veers into your house, you may have little or no structure left. I'd be prepared for providing my own shelter during the rains that come after the hurricane has passed over and before the streets and roads are cleared for driving away.

My general theory is to be prepared to shelter in place. Everyone leaves, and you end up with no motel rooms available for miles around, no gas at the stations as no one filled up before leaving home, few or no groceries as everyone stocks up in a panic, etc.

I know others prepare by having guns, but I have none. If you're not willing to kill someone with it, you have to be prepared to be killed holding it (or by it when they take it away). In the general disasters of blizzards and hurricanes, few people are killed by criminals, many are killed by driving across flooded roads. My advice: don't drive across flooded roads, and you'll be fine. (If the disaster occurs while you're at the Pentagon, you'll be better served by the contents of your bail out bag. :->)

I wouldn't worry about having a gun. I'd worry about having seasonally and locationally appropriate survival gear in my car, my home, and my office. It sounds to me like your pretty much set; I'd add supplies to your home and office to sit out a major storm for a week, maybe more. The weather in your area is not usually that severe.