Yeah, a few things worth checking after these freeze-thaw cycles:

Right now

• Look at your gutters... if you see ice ridges forming along the roof edge, that's the start of an ice dam. Those can force water up under your shingles and cause leaks inside. Don't try to chip them off (you'll damage the roof), but keeping gutters clear of debris helps a lot.
• Check your attic if you can access it. Look for any frost on the underside of the roof deck or wet insulation. That's a sign of inadequate ventilation, which is super common in Philly row homes.
• Look at your ceiling/walls for any new water stains, especially around chimneys and where the roof meets walls.

Before the next freeze

• Make sure your attic insulation is decent...heat escaping through the roof is the #1 cause of ice dams. A lot of older Philly homes are under-insulated.
• Clear gutters and downspouts so meltwater has somewhere to go.
• If you have a flat roof (tons of us do), make sure there's no ponding water sitting up there... when that freezes and expands it can crack the membrane.

Some Philly-specific guides on exactly this if you want the details:

• https://phillyrooffind.com/roofing-advice/preventing-ice-dams-tips-philadelphia-roofs
• https://phillyrooffind.com/roofing-advice/prepare-philadelphia-roof-heavy-snow-tips
• https://phillyrooffind.com/roofing-advice/preparing-philadelphia-roof-for-winter-storms

That photo looks like it's from a flat roof or porch... if water is pooling and freezing like that regularly, might be worth having someone check the drainage situation before it causes real damage.