Currently: A cold front is in the process of crossing the border into Buffalo, NY. This front will set the stage for a potential historic winter/spring storm tomorrow and tomorrow night.
Tonight: Generally a quiet night. Although there is the chance for a quick shower or sprinkle with the cold frontal passage. The best chance of that would be around or just before midnight. I have added chances for showers into the fcst tonight, as lift has improved in recent model runs. As far as temps, I don't have any reason to differ with the NBM guidance, as there isn't a strong signal one way or another. Look for lows in the low 40s.
Tomorrow: As the parent low moves into the Ohio Valley, a new low will develop somewhere near the E coast. Rain should develop late in the day and become fairly heavy at times. Most of the day should be dry. however. As for temperatures, I'll go a few degrees under the NBM guidance, with clouds arriving and cold air advection. Look for highs to be in the 50-55 degree range.
I am adding a special period for tomorrow night, to convey what is going to happen with our developing storm. Rain will fall heavy at times for much of tomorrow night. As cold air moves in, many parts of the state, except maybe the immediate south coast, will mix with and change to snow, especially during times of heaviest precip. Srn CT should not see any accums, but anywhere with any kind of elevation and anyone from I 84 N should see an inch or two, mostly on colder sfcs, but the potential for locally more. As for temps, I followed statistical guidance fairly closely, with a nudge down in a few spots. Lows should generally be in the mid 30s. Stay tuned for any updates regarding potential snow accumulations. Remember, even a flake or two on the S coast and an inch or two in N CT is historic for the time of year!
For Saturday, as the low pressure system wraps up to our north, look for wrap-around showers. Any heavier showers could mix down cold air and fall as sleet or snow, while lighter showers should be rain. Winds will become very strong, with gusts in the 40-45 MPH range possible. It will also be very cold for the time of year. NBM guidance was used for temps verbatim. This keeps the entire state below 50 for highs on May 9, with some sun! Highs should be in the mid to upper 40s!
Long Term (Sunday and beyond): The main feature during the long term is an Alberta Clipper system (yes, unusual for May) centered around the 2nd half of Monday. After that, thermal contrast should set up another rain event for the area, beginning on Thursday. Depending on the evolution of the pattern, that one could be a long duration rain event.
First, for Sunday, expect partly to mostly cloudy skies, but no precip. Not a horrible day, but rather chilly for Mother's Day. NBM guidance was generally accepted, and this yields highs in the mid 50s.
On Monday, an Alberta Clipper system will slide to our south. This should produce another period of pcpn, followed by another cold shot. Look for rain to develop during the early afternoon hours, from W to E. There could be a few bursts of heavier pcpn, and there is even a slight chance of t-storms. Although precip is expected to be all rain with this one, freezing levels are very low, so any tstorms could produce small hail. With pcpn arriving and cold air aloft, I went a few degs below guidance for temps. Look for highs of only 50-55.
Monday night rain ends rapidly and skies clear. Tuesday should be a generally fair day and still very chilly for the time of year. Did not fuss too much with guidance. Highs should once again only be in the mid 50s, and even cooler in the NW Hills!
For Wednesday, temps should finally moderate a bit, as high pressure moves overhead. It should be a sunny and pleasant day, with highs a few degrees warmer- in the upper 50s, except still a bit cooler in the NW Hills. Guidance was accepted for temps.
Guidance then diverges in the long, long term, but the general feeling here is that the wx will tend to be unsettled. The overall pattern modifies into one where we have a battleground between high pressure in Srn Canada, and the developing Bermuda High, with the former being stronger than normal and the latter being weaker than normal. This should create an impressive thermal gradient across the area, and promote the development of rain. So I'll go rainier for Thu than the model consensus has for now. And if I'm going rainier than consensus, and consensus has partly to mostly sunny skies, I'll also need to chop off about 5 degs from consensus temps. This gives highs still only in the mid to upper 50s.
In the longer range, the pattern looks to become one more usual for spring, with a general moderation in temperatures expected. However, with very cold air lurking nearby, and warm air trying to make inroads on the area, I would anticipate more unsettled wx than normal, with growing chances for showers and thunderstorms.
Now, let's take a quick look at some weather systems to affect our area. I'll post tomorrow night's storm and then Monday's clipper. I am not going to post Thursday yet, due to too much uncertainty. When looking at this map, valid tomorrow night at midnight, I can't help but wonder what type of a snow bomb this would have been in winter! Maybe even a month ago, this could have been a big April snowstorm!
-GP!