Last night’s models did very well with the light snow that should be ending within the next hour.
Here’s the latest on the Saturday to Sunday storm. For Philadelphia and its immediate suburbs, a total storm QPF is about 1.95 inches water. Most of this precipitation will be rain, but the beginning and end of the storm will have snow or mixed precipitation.
Based on the latest 06Z run of the NAM and GFS models (1AM last night), the NAM is holding off much of the precipitation until temperatures rise enough when the precipitation begins towards evening. Temperatures in all levels of the atmosphere will minimally support snow, so between 5 and 7 PM Saturday, expect some light snow rapidly mixing with sleet and rain and then all rain by 9 PM. In the far northwestern suburbs, an extended period of sleet and freezing rain may be occur and areas near Allentown may remain a frozen mix until midnight.
The GFS also has the atmosphere warming, but it has more precipitation starting somewhat earlier in the late afternoon, with greater mixed precipitation accumulating before the changeover to rain about 9 PM.
The Arctic front moves through about daybreak Sunday. Temperatures plummet from about 40 at 7 AM to 28 at 1 PM and 17 by 7 PM. Little moisture is left with this drop in temperatures. A change back to snow is expected Sunday morning, but accumulations in the immediate PHL area and surround suburbs will be minimal Sunday, according to latest models.
Stay tuned for more updates. We’ll be in better range for specifics tonight and tomorrow morning.