Nov 30: Rain Moves In

Due to technical difficulties, a full update will not be posted tonight. The 5-Day Forecast page was not updated, though for the main part the expectation remains the same with very little changes.

Tonight And Tomorrow: Storm Brings Rain, Wind, Thunderstorms

An unexpected round of light rain developed earlier today as the storm started affecting Pennsylvania, as the storm was not supposed to bring widespread rain to the area until at least tonight. Rainfall amounts were generally light from this round of rain, and it is currently cloudy across the area. A warmer air mass is currently moving into the area, with 850 mb temperatures expected to reach 10c by tomorrow morning. As a result, temperatures will steadily rise tonight, reaching the mid to upper 50s by the morning. Occasional showers will fall tonight, however the heaviest rain will hold off until tomorrow. In addition, expect winds to increase tonight, coming out of the SSE.

The line of heavy rain and thunderstorms we are currently seeing affecting the eastern Ohio Valley will move into the area by tomorrow, affecting the area from west to east between the morning and the evening hours. This will produce heavy rainfall, strong winds gusting near or over 50 mph, and thunderstorms as well. Rainfall amounts are expected to range from 1.5 to 2.25 inches inland, 1 to 2 inches in the immediate NYC area, and 3/4 to 1.5 inches in Long Island/S CT. The winds should calm down by the overnight hours, but breezy conditions will likely continue.

Longer Range Outlook: Cold Pattern Settles In, But Will Snow Fall?

Between Thursday and Saturday, the forecast remains the same as yesterday. A cold air mass moves into the area, which given the -NAO is expected to settle in and not quickly exit like previous cold air masses have done.

By Sunday, however, uncertainty increases. With yesterday’s update, I mentioned how a clipper could produce snowfall for the Mid Atlantic. Today’s models, however, backed away from the clipper, and the models that do show the clipper have it very weak and dissipate it west of the Appalachians. As this is over 100 hours out, and the models are not consistent yet, changes are expected with the solution, and it is possible that the models trend back to the clipper solution with snow in the Mid Atlantic, however at this time, it is starting to look less likely that we see a scenario like the one mentioned yesterday. Stay tuned for more details on this potential over the next few days.

Afterwards, the models continue to show a strong -NAO with several consecutive retrograding storms hitting Maine and Nova Scotia while cold air stays trapped over the region. While there is also uncertainty with this solution, it does seem likely that at least for the first 1-2 weeks of December, a cold pattern will be in place, with temperatures below average, potentially bringing highs in the 30s for the area and lows in the 20s with 10s inland. The question at this time is whether the pattern can become favorable for snow events, as the current scenario that the models are showing suppresses any storm that tries to develop. Stay tuned for more details on this time frame.

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