Feb 21, 2013: Stormy Pattern Continues

Forecast Highlights:

Cold and windy conditions continued today across the area, although the overnight lows ended up warmer than expected with increased cloud cover last night, with temperatures failing to drop much, in some cases not dropping at all. Warmer temperatures are expected to return for Friday into the weekend as the next storm approaches, producing moderate rain across the area and some snow for interior locations. The pattern only becomes more active afterwards, however, with another storm on Tues-Weds followed by a strong trough to start early March.

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Tonight - Friday: Warming Up

Winds are expected to gradually weaken tonight into Friday, shifting towards the north tonight and the east by Friday afternoon, with clearing cloud cover expected as well. Cool temperatures are expected tonight, dropping into the mid 10s to low 20s inland and low to mid 20s for NYC and coastal areas, with warmer temperatures for Friday returning into the upper 30s to low 40s across the area as cloud cover increases ahead of the next storm.


Friday Night - Sunday: Rain, Some Snow

A major snowstorm currently affecting the central US will affect the region during the weekend, as it continues to weaken and track into the Great Lakes while a coastal low pressure develops near the Mid Atlantic coast and tracks northeast. While yesterday, the model guidance was in agreement regarding a major storm affecting the region with a significant New England snowstorm, today's trends have been for a further southeast and weaker storm that takes longer to develop, with less favorable dynamics resulting in less rain and snow as a whole for the region. Some additional changes are still expected over the next 2 days as the models gradually settle on a consensus, and the storm could still end up slightly stronger or weaker than currently expected. Despite the storm taking a track that typically would support a snowstorm in the area, the primary low over the Great Lakes brings a warmer air mass into the region, with the development and intensification of the coastal low taking place too late to support a snowstorm, instead favoring interior New England for a wet snowstorm.

The current forecast remains mostly unchanged from the last few days, with a moderate rain event still expected with some snow for interior areas. Scattered precipitation is expected for Friday night into Saturday morning, mostly in the form of light snow north/west of NYC into southern CT and a mix or rain from NYC and further south/east, with light accumulations for interior parts of the area. As the coastal low makes its closest approach to the area, steadier rain is expected to develop from the late afternoon through the early-mid overnight hours, especially from NYC and further east and northeast; temperatures are expected to be in the low to mid 30s inland and mid to upper 30s for the rest of the area, supporting rain, even for interior locations, although southern CT away from the coast may see a changeover to snow at the end of the storm. Rain amounts are expected to end up generally under an inch, with the highest totals in Long Island and lowest totals in western parts of the area, along with the potential for light snow accumulations in interior SE NY and southern CT, especially away from the coast. The forecast is still subject to some revisions, however, and more information will be posted on Friday and Saturday's updates.


Next Week: Another Storm For Tues-Weds

Partly to mostly sunny conditions are expected to return for Sunday and Monday, with temperatures failing to cool much behind the storm; highs on Sunday are expected to reach the low to mid 40s across the area, perhaps exceeding 45 degrees in the immediate NYC area, and ending up slightly cooler over southern CT, with mostly sunny skies on Monday and highs in the low to mid 40s inland and in southern CT with mid to upper 40s for the rest of the area.

The next storm will affect the region on Tuesday into early Wednesday as the stormier pattern continues, and for parts of the region will have more significant impacts than the weekend storm. Until this point, the models generally showed this as a heavy rain event, although some of today's runs have trended colder, showing more snow to start for interior areas followed by a changeover to rain. While the low pressure initially tracks towards the Great Lakes region, as with the weekend storm it will be blocked from continuing on this path as ridging is expected over southeastern Canada, which will also play a role in the longer range outlook, but unlike the weekend scenario when a coastal low develops and tracks offshore, in this case a secondary low is expected to develop around the Mid Atlantic region, close to the area, while becoming negatively tilted and becoming cut off over the northeastern US under the Canadian ridging.

At this time, the focus of the storm is likely to take place towards Tuesday into Tuesday night, possibly into early Wednesday, with the potential for moderate-heavy precipitation. Exact precipitation amounts and types across the region are still uncertain at this time considering this is still 5-6 days away, and additional changes are still expected with the models, although parts of the Northeast, perhaps including parts of the area, may end up with snow. Stay tuned for more information on the midweek storm.


Longer Range: Colder Pattern To Continue

With ridging and above average 500mb heights present over southeastern Canada, the pattern continues to get increasingly active into early March. As previously mentioned, the late week storm is likely to become cut off over the region, which will keep a trough sustained over the region through at least the beginning of March with temperatures near to above average over the area and the Northeast and below average further south, in the Mid Atlantic and southern US. Meanwhile, some of the longer range model guidance has been hinting at a storm potential around early March, and along with the potential pattern, this storm possibility will continue to be watched, although this is still in the longer range and easily subject to change. More information will be posted on the longer range as details become clearer.