Tuesday, July 23, 2013

Muggy, Thundery, Summery


Yesterday's and last night's heavy rain and thunder in parts of the region will continue on into today as disturbance finishes lifting through the Mid Atlantic. Scattered areas of showers and storms will refire during the course of the day, any of which could produce localized downpours and heavy rainfall.

Philadelphia picked up 2.49" of rain between 1 and 4 AM from heavy thunderstorms that blitzed through the region, with that total one of the higher in the area. While many spots picked up an inch plus, the two inch plus rainfall was localized to a few locations (the Airport being one of them).

The atmosphere is still quite muggy as dew points are pushing 70 or higher in many locations, with precipitable water rates north of two inches, which supports the potential for torrential downpours in any storms that do develop. The risk for localized flooding does exist, especially in areas that got popped pretty good yesterday afternoon.  Flash Flood Watches are in place for much of the Delaware Valley.  Unlike last night, storms today appear to be more scattered in nature and not as widespread...so we have that going for us.

Temperatures this afternoon depend on the amount of sunshine that breaks out over the course of the morning and midday hours. Modeling has been waffling between low 80's and pushing 90 the past couple of runs, in concert with varying amounts of precipitation (more precip in the cooler runs, less in the warmer).  The thought here is that storms will be scattered and not widespread enough to keep temperatures from being too "cool"...hence, a mid 80's type forecast where we're splitting the middle between the less warm and warmer runs.  Regardless, it will be muggy with dew points pushing 70 through the day and a heat index value that will be several degrees warmer than whatever the temperature is.