After two very busy weather weekends, a pretty quiet and nice one is on the way (by winter standards). As Thursday's storm (the miss to the south) continues to pull away, the pressure gradient will weaken, allowing winds to gradually calm down. New England’s extended thaw will begin in earnest, with Saturday ticking warmer than today and Sunday ticking another notch warmer than Saturday.
Zonal flow (when the jet stream has a stronger west to east motion and lays flatter across the United States) tends to promote near average temperatures as deep troughing or ridging is absent. In this specific case, however, everything is lined up for a strong Pacific influence to spread across the United States. When the Pacific is the main influence in weather across the country, it leads to a milder flow and temperatures, allowing temperatures rising above average for a time early next week.
Temperatures will continue to tick a notch warmer each day through about mid-week. After a few days of building mild weather, Tuesday and Wednesday will likely see the peak with widespread 40s across the region. Southern and central New England will have the chance to reach into the low 50s. This is far from being a lock, but if enough sunshine and mixing of the boundary layers occurs, low to even mid 50s will be a possibility for the southern New England coastal plain.
Aside from temperatures, zonal flow also promotes unimpactful weather as storm systems don't have the setup to organize and become stronger. Overall, this will be a repetitive pattern for New England over the several days as several northern stream disturbances cross the region. These disturbances will be weak and extremely moisture-starved. This will bring times of precipitation and unsettled weather, but nothing long lasting or impactful.
The first of these disturbances will be an elongated trough that crosses New England on Sunday. This weak system may provide just enough forcing and lift to generate some scattered snow showers across the northern tier Sunday morning. A stray flurry will be possible anywhere in the region as the system passes overhead.
Below: RGEM showing potential weather early Sunday morning:
Additional weak disturbances look to dart through the zonal flow on Monday and Tuesday, bringing the chance for additional rain and snow showers at times through each day. With little moisture and weak lift, these will likely result in not much more than a few spot showers (rain and snow) popping up each day, scattered around the region.
A more robust system may enter the picture Tuesday night into Wednesday, but it currently looks like potential cyclogenesis will occur only once the system passes New England, well offshore. The highest moisture availability for the system also looks to exit ahead of the best forcing from the system. This would result in more of the same with nothing more than a period of scattered and light showers, mainly across the northern tier.
Below: Euro showing potential weather early Wednesday morning with the bulk of precipitation passing offshore:
The Tuesday and Wednesday disturbances may end up deciding whether or not 50° can be achieved in southern New England. While not much by way of precipitation is expected, an increase in clouds could mean the difference between upper 40s and low 50s for southern New England's coastal plain.
Overall, the northern and southern streams will likely fail to sync up to bring any kind of phasing between systems. Without phasing, the northern stream disturbances passing through will remain weak and moisture-starved. This separation keeps the southern stream from injecting the northern stream with energy, precluding any big and widespread storms.
Below: General jet stream flow early next week, showing zonal flow keeping the polar jet and southern streams generally separated:
With a lack of deep moisture, it will be difficult for these systems to produce much by way of precipitation (both rain and snow accumulations). The current 5-day precipitation forecast has most of New England staying at a quarter inch or less through Wednesday night. Much of southern New England is being shown as a shutout as most of the activity will be limited to the northern tier.
Below: Current 5-day precipitation forecast:
Heading later into next week, the mid-level flow will become less zonal and more amplified with a ridge-in-the-west-trough-in-the-east pattern beginning to take shape. This brings about more widespread precipitation chances around Thursday of next week. A pair of disturbances will likely traverse the region, but look unlikely to phase at this point. This would result in lighter precipitation.
The system has also been trending warmer with a potential rain/snow line and potential winter weather impacts getting pushed farther north over the past couple days. The only thing to watch out for would be surface low development off the coast. This would bring cooler temperatures into the picture. As of now, Thursday is looking to be another mild day with very limited support for a coastal low.
The next system will likely arrive next weekend. At this point, it appears to be a clipper-type system with the potential for rain or snow. When zonal flow is in place, confidence decreases in longer range forecasts with storms as the quick timing of storms can be especially difficult for models to figure out, so it’s not worth trying to go into any kind of detail with this system right now.
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