Latest HRRR has scattered showers mid morning Saturday.(the NAM keeps these showers further west.) :
Latest NAM has heavy rain between 8 am and 11 am on Sunday:
Some changes in the forecast have cropped up since this morning.
Here’s the revised summary from earlier today: A series of weak disturbances emanating from a low pressure system in the Midwest will pass through our area Saturday into Sunday.
The forecast for Saturday has changed significantly. Some rain and scattered showers are expected to develop before daybreak and linger into the morning hours, tapering during the early afternoon. Both the NAM and GFS show this, but there are huge differences in timing and QPF values. The NBM maintains a moderate chance of light on-off showers through the day. High temperatures 72
The main surface low pressure system approaches Saturday night with heavy rain developing after midnight.
For Sunday and the Broad Street Run, depending upon the model, the heavy rain exits about 8-9 AM (GFS) or lingers later into the morning (NBM, FV3-GFS). The NAM is somewhere in the middle. Either way, low clouds, and some light sprinkles or drizzle in an easterly flow will make for a drab day. It will be windy in the morning. High 64
With such a dramatic shift in the forecast for Saturday, I would expect that additional changes in the forecast are likely for Sunday. Stay tuned.
The weather is looking better for Sunday morning. Details later
A series of weak disturbances emanating from a low pressure system in the Midwest will pass through, mostly during the nighttime hours Friday through Saturday night.
For Saturday, showers Friday night will move away, allowing partial clearing, some sun and dry conditions for much of the daytime Saturday. High temperatures 76-80 (EKDMOS) or 75 (NBM). Light winds.
The main surface low pressure system approaches late Saturday into Saturday night. Rain develops, possibly heavy before daybreak Sunday.
There remain some differences in the forecast for Sunday and the Broad Street Run
The GFS has the low pressure system exiting by mid-morning with rain decreasing considerably.
The latest FV3-GFS and the NAM show an upper air disturbance causing a slowing of the exit of the surface low with considerable rain for much of the day, tapering in the afternoon. High temperatures 65-68 (EKDMOS- with large statistical spread) or 63 (NBM). Fairly windy in the morning.