*8:45 AM update – the latest trends in high res models as well as radar has been to delay timing a bit for the rain this afternoon. It also doesn’t appear as though the heaviest rain will arrive for most this afternoon/evening but rather this evening and into tonight. Still be watching for a few sprinkles between now and noon before steadier rain looks to move in. Othewise, the forecast is looking on track for today.*
Last night’s front has pushed and stalled just offshore and a wave of low pressure is developing off the Mid Atlantic coast. Showers are moving into Southern New England as well as Southern Vermont and both of these are moving in our direction.
Here is a look at the surface map and radar this morning showing our front, developing low pressure, and the area of rain headed our way in the next few hours.
As you can see above, currently most areas are dry and that looks to continue for most through about 8 AM. Southern NH stands the best chance for some raindrops before then as showers over southern VT move east. For most of the rest of us, thoughts of raindrops should start entering our minds in the 8-9 AM hour. While the widespread rain will likely hold off until later, this is the time when showers could start popping up. While not everyone will see raindrops before 11 AM or so, the threat starts to become umbrella/raincoat worthy around 8. This timing holds most true for areas south of route 2. Up north, there will be much less rain and it is likely to start later, more towards the 3-4 PM hour.Simulated radar from the HRRR model shown below illustrates one possible evolution of the approach of showers to the area this morning.
Steady and heavy rain moves in the afternoon hours and by 4-5 PM, the idea of a deluge should start to enter your mind. While this coastal storm, as early season ones usually are, will be pretty weak and on paper not that impressive (In January we would hardly notice), this storm has a deep tropical connection with roots in the Bahamas and that moisture pipeline will be open for business. Again, this timing holds most true for southern areas. Up north will likely have to wait until the overnight hours before they pick up the heavy rain. Heavy rain will continue through the overnight hours but as Friday approaches, the forecast becomes more uncertain in terms of when exactly the rain clears out. At this point it appears some of the morning hours will be wet and some of the afternoon hours dry. I’ll have more details in tomorrow morning’s update.