Disc: Major storm system will wind down across the region. The rain is done, aside from some showers rotating around the upper level low, and winds, which will be very strong this afternoon, will diminish once the sun goes down.
Currently: Very strong low analyzed over the NH/VT border near Bennington, VT. High pressure behind the low extends from Southern Missouri to Hudson Bay. The gradient between these two systems and daytime heating is combining to produce very strong winds. This will continue until around sunset. In addition, an upper level low that the nor'easter left behind is producing showers, mostly across the NW hills, which will also diminish with the setting sun.
Tonight: Because I do not expect much clearing, I'll go with the warmer GFS MOS. In addition, without much clearing and still breezy conditions lingering, temperatures should be pretty uniform across the state, with lows in the upper 40s.
Tomorrow: Conversely, for tomorrow, as we will still have some cold air advection, I'll go with the cooler NAM guidance. The GFS MOS performed horribly during the daylight hours today and with much of the same air mass in place tomorrow, I don't expect too much of a change. So expect highs only in the mid to upper 50s.
Tomorrow Night/Sat: Some areas in the NW Hills could see their first freeze tomorrow night. Refer to products from NWS BOX and ALY regarding freeze products. On Saturday, high pressure moves overhead. With cold air advection ceasing, I'll go closer to the GFS MOS, but hedge a degree or two colder in deference to the NAM and the cool start. So expect highs generally within a few degrees of 60 most places, but mid 50s in the NW hills.
Long Term (Sunday and beyond): Sunday could be a little bit interesting. Current NHC guidance is in very good agreement with the GFS regarding the track of TD 16/future NESTOR. Taking that track, it would pass harmlessly south of the region, with the only effects being high clouds along the south coast. However, this all depends on the position of the high pressure system and it would not take a huge adjustment to bring the storm close enough to at least brush the south coast with some rain. For now, I will take the course of least regret and not call for any significant effects in our state. The NAM brings precipitation to the southern half of CT, but that model has done very poorly at that range for quite a while. For now, I'll go 90% GFS with this forecast and maybe just bring the cloud shield a bit further north, since systems generally tend to be a bit north of progged. With this in mind, I'll shade temperatures a tad below guidance and go with low 60s for highs.
Monday should be a bit of a break between whatever happens with Nestor's remnants and an approaching storm system/cold front. Expect a generally fair day. On a day like that, with no extenuating circumstances, there generally isn't a good reason not to just follow guidance. So that's what I did, and I expect temperatures to range between 60 and 65 for highs.
On Tuesday, a cold front will approach, along with a low tracking into the Lakes. For now, this system looks more well-behaved than the last one, i.e. I am not expecting a bombing secondary low. So we'll go with a more traditional cold frontal passage for now, with a quick shot of heavy rain accompanying the cold front. This is a strong cold front, so the chance of thunderstorms is not zero. However, being that it's getting into late October and temperatures are not expected to be super warm, I am going to exclude them from the forecast at this time. I am going to take a risk here and go well below guidance (5-8 degrees) for high temperatures on Tuesday. I am using yesterday as a reference point. Despite southerly winds at the start of the storm yesterday, low dew points halted any temperature rise as the rain began to fall heavily and guidance busted badly. That part of the Tuesday system could turn out to be similar, especially given two factors 1) precipitation moves in during the heating of the day, and 2) for locations south of the Merritt Parkway, a southerly wind blows off the cool Long Island Sound. Given all this, I'll only call for highs near 60 on Tuesday.
Wednesday should clear out behind the front and it should become a bit windy, though not near as windy as today- maybe max gusts around 35 MPH. With cold air advection, which the GFS seems to think is a unicorn, I'm going to go 5 degrees below that guidance for Wednesday's highs, in deference to what's happening today, and call for highs in the mid 50s.
With high pressure moving overhead on Thursday, guidance temperatures seem a little closer to reality. Still though, because of a low launching point, I lowered guidance temperatures a couple degrees. So expect highs within a few degrees of 60.
A quick note on the next system beyond Thursday... it appears a cold frontal passage is set for Friday. Once again, at least for the time being, it appears that it will be more of a traditional cold front, with a quick shot of moderate to heavy rain, and then clearing. However, it should be noted that this is going to be a stronger cold front than what we have been seeing recently and with the crashing thermal profiles behind that front, I would not be surprised at all if places north of I 84 see some sleet pellets mix in as precipitation ends.
Looking further out into the long range, again with such an active pattern right now, I haven't dedicated much time to this, but it looks like a mean trough is about to set up shop across the Eastern CONUS with blocking up north. This translates into a cold, active pattern in fall and winter, so stay tuned!
Now, let's take a look at systems expected to affect the area in the coming week. First, I'll post the GFS as it shows the future Nestor's closest approach. This is the preferred solution at this time. On this image, Nestor's remnants are located near Cape Hatteras, and from there, headed NE, out to sea. You can see if that high pressure was a bit NW of progged, the storm would be forced farther north. It's NOT the forecast right now- just something to keep an eye on!
The next image is Tuesday's cold frontal passage. Notice there is a weak wave of low pressure near Montauk. For now, we'll just call it as we see it and call that nothing more than a rainfall enhancer. However, it's also something to keep an eye on, just in case it strengthens more than progged.
That's all for now! See you again next week!
-GP!
-GP!
