Today would be an excellent day to have lunch delivered. The National Weather Service has issued a flood watch through this evening. An inch of rain is expected to fall today, with locally higher amounts possible. The rain should fall over a several-hour period so we don't anticipate any widespread subway stoppages. Temperatures will hold steady in the mid-50s or even drop slowly during the day. Throw in a gusty easterly wind and you have a stereotypical spring day!

As mentioned earlier in the week, and we love it when a plan comes together, a strong low pressure system is travellling eastward along a formerly stalled cold front. The low will stay to the south of the city as it moves eastward, pushing moisture up and over the old front to trigger the rainfall. The Weather Service and Weather Channel are disagreeing on how long the rain will last. The former says the heavy rain will be over this evening with only lingering showers overnight before clearing tomorrow. The Weather Channel continues the chance of showers through tomorrow. Gothamist finds the Weather Service's solution to be more realistic. Both have the city being sunny and 70 on Sunday.

While there will be plenty of rain today, the atmosphere is not unstable enough to produce a thunderstorm. We'll have to settle for a gallery of dirty thunderstorm photos. The pictures were taken during the eruption of the Chaitén volcano in Chile this week. Electrical charges sometimes build up in the rock and ash of an erupting volcano, causing an intense lightning event known as a dirty thunderstorm.

Northeastern radar from the National Weather Service