Today’s forecast went well and there’s little change in the forecast for Sunday.
The models are all on-board for rain on Sunday, with this afternoon’s GFS and NAM having a QPF of 2.5 and 1.5 inches water respectively.
Rain starts well before daybreak and is heavy at times, especially in the morning. The models have rain continuing through the day, tapering and ending as late as 6 or 7 pm.
Looking back, the FV3-GFS had the most consistently correct forecast for Sunday.
The light showers predicted by the Friday evening model runs are still in the forecast for this morning.
The 2AM EDT (06UTC) model runs (the “off hour” runs) of the NAM and GFS continue to show light showers for mid-morning, but some suggest the heaviest showers will be to our west and south.
Any showers end by late morning today and from 11 AM on, it should be dry until this evening. Varying degree of cloud thinning is expected with bright spots, possibly some sun.
Unfortunately, all models have jumped on the scenario of rain, possibly heavy, for Sunday morning. I’ll have more on this later today.
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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:
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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.
