[su_note note_color=”#d9f2da”]Thurs 7PM Update : Saturday is looking to be the better of the two days this weekend. Saturday will be dry, but the models are suggesting periods of cloudiness, just north and west of the city.
Sunday looks to be unsettled with considerable cloudiness and a chance of showers, both in the morning and especially in the afternoon. It will be warm and humid.[/su_note]
Speaking of the FV3-GFS, the model shows a disturbance moving through on Saturday afternoon, a pseudo-warm front. Saturday starts sunny, but considerable cloudiness develops in the afternoon. High 84. Low dew points to start, but it becomes more humid later in the day.
Sunday looks to be cloudy very early, then hazy sunshine, very warm and somewhat humid. High 88. Thunderstorms originally expected in the afternoon now are forecast to move through about 7-8 PM.
Today, with its morning model run, the National Center for Environmental Prediction (NCEP) will have upgraded the GFS model (version 14) to the new and improved FV3-GFS (GFS version 15.1.1). The FV3-GFS becomes the main global model of the National Weather Service today.
The FV3-GFS (Finite Volume Cubed Sphere) has been in development for well over 10 years and has been in testing for the past three. It uses a different three dimensional geometry to reduce errors inherent in all numeric weather models. It includes different modeling physics and new parameters. Significant information on the FV3-GFS can be found here. Background information is here.
The model data has been available on university web sites in a very limited fashion for awhile. Over the past two weeks, the NCEP made the data available on the main weather model download server, “NOMADS”.
The FV3-GFS has been heavily evaluated and is considered “equal or better” than the current GFS.
[su_note note_color=”#d9f2da”]Sun 8 AM : The short range high resolution models have the clouds coming in somewhat earlier than the FV3-GFS and GFS. About 2-3 PM. The FV3-GFS still about 7 PM. It will become quite windy today. Areas to the north of Philadelphia will be sunny most of the day.
Current RAP (Rapid Refresh Model) cloud composite for 2:30 PM Sunday
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Tonight’s NAM keeps the main cloud deck just to our south for much of Sunday. High clouds at times, but lower clouds aren’t forecast to move in until 4-7 PM. High 76-78
The WRF model, just available, has the clouds moving in about 1-3 pm, earlier just south of the city.
