Here’s the forecast for this weekend – Very Nice Weather. 🙂
Weather Update
A quick update- No significant changes since yesterday, except the NAM has been trending towards colder surface level temperatures. QPF values still about 0.80. Timing of precipitation still looks on schedule, with snow starting about 8 AM or so and ending a around sunset.
The unknown is how much dynamic cooling will occur if precipitation rates are high. Still likely to be only grassy surface accumulations, except where elevations are higher and except where bursts of heavier precipitation allows for dynamic cooling. Either way, interesting weather for April.
10AM: This morning’s NAM model has brought the QPF way down to 0.40 inches water. With less precip, there will be less dynamic cooling and even less likely for there to be accumulation.
Philly Weekend Weather Forecast
An interesting weekend weather forecast for the beginning of April…
See my posts earlier this week for the synoptic details.
Previous weather outlooks for the snow this Saturday appear to be supported by the latest weather model runs. Both the GFS and NAM crank out a QPF between 0.65 and 0.80 inches of water.
(If this were February, we’d have a significant snowstorm on our hands. But it’s April and that’s going to make a huge difference.)
Sun angles are high and the effects of solar insolation through clouds is prominent, preventing much, if any, accumulation on dark asphalt roadways. Additionally, near-surface temperatures won’t be at or below freezing until late in the day. So accumulations won’t really be a concern.
That said, it will be cloudy on Saturday, with wet snow mixed with rain, heavy at times, becoming all snow later in the afternoon. Very windy! Highs near 40, but dropping to 32 late afternoon. Grassy accumulations possible with icy conditions possible Saturday evening. Greater accumulations north and west of Philadelphia.
Looks to be partly sunny and unseasonably cold on Sunday.
Friday 6 PM Update: Latest NAM model really cranks out the precipitation, with a QPF of over 1 inch water. The NAM has also dropped the temperatures into the 30s. It’s possible this could become a freak spring snowstorm with accumulation! Updates later tonight.
Friday 10:40pm Update: No significant change. The forecast above captures everything well. Maybe less windy and maybe a midday transition to rain before changing back to snow.