Update: Included an update to current snowfall forecast:
We feel pretty confident in the overall trend of our forecast with the highest amounts north and west of Providence, but the latest information into the Live Pinpoint Doppler 12 Forecast Center has created a tricky forecast for Rhode Island and parts of Massachusetts.
The snow is made above our heads, obviously, and the computer models we use as tools to create our forecasts show similarities above our heads. Below are a couple of maps with a bunch of squiggly lines in different colors. To an untrained eye, it’s difficult to understand, yes. Bottom line, look at the pink line just south of Rhode Island and south coastal Massachusetts. This is from the high resolution NAM computer model.
Now look at the GFS computer model, which shows a very similar position to that pink line. That line is the 0°C line or 32°F line, or where melting will begin to take place.
The problem with these two computer models is that the NAM shows a big hit with snow even into the Providence area, while the GFS brings rain all the way through Rhode Island. So obviously there are some issues below the 4 to 4500 ft layer that the computer models are not resolving well (or one isn’t resolving well). That’s the tricky part of the forecast. The Pinpoint Weather Team’s thinking is that the storm will be producing so much energy in the atmosphere that it will be producing it’s own cold air. The rain/snow line area remains right over the Providence area, but the cold air the storm generates should overpower that and produce some periods of heavy, wet snow late afternoon and early evening. After that, the winds should turn more northerly and colder air sinks into the area, keeping the precipitation as all snow for most of Rhode Island.
Other computer models we look at are also now showing more snow into the Providence area. Those models have a higher resolution, meaning they see things in a smaller scale than computer models like the GFS. The three images below are the high resolution RPM output for late this afternoon and evening. This model catches some of that storm-produced cooling.
Notice how the rain/snow line moves back and forth, but Providence stays in the snow. There will likely be times the city sees rain, especially this afternoon, but snow is likely in Providence, and some of that snow could be heavy at times. The timing of that heavy snow could be bad—during the evening commute.
Here is our latest forecast: Six to ten inches possible north and west of 295. Four to six inches are now expected in the Providence area, with one to four south and east of Providence where rain will be mixing in at times.
-Meteorologist T.J. Del Santo
STORM READY LINKS: Storm Ready Resource Guide | Interactive Hurricane Tracker | Evacuation Routes & Storm Surge Maps | Ocean & Bay Forecast | Latest 7 Day Forecast | Pinpoint Weather Blog | Live Pinpoint Doppler 12 Radar | Threat Tracker | Pinpoint Traffic | WPRI.com Flight Tracker | Closings & Delays | Download: Pinpoint Weather App | Download: Eyewitness News App | Sign Up: Weather Alerts