Хойд Америкийн эрэг орчмыг дайрч буй энэхүү цаг уурын үзэгдэл нь халуун орны шуурганы зарим шинжийг харуулж байгаа нь эрдэмтдийн анхаарлыг татаж байна.
Хойд Каролинагаас Нова Скоша хүртэлх эргийн бүс нутгийг чиглэн ирж буй “нор’ийстэр” (nor’easter) хэмээх нам даралтын энэхүү систем нь лхагва гарагт бүрэлдэж эхэлжээ. Энэхүү шуурга нь баасан болон бямба гарагт Нью-Энглэнд орчимд хүчтэй салхи, аадар бороо авчрах төлөвтэй байгаа бөгөөд салхины хурд цагт 60-70 милд хүрэх магадлалтай байна.
Ердийн үед энэ төрлийн шуурга нь өвлийн улиралд тохиолддог бөгөөд дээд агаар мандлын хүчтэй салхинаас энерги авдаг. Гэвч зарим компьютерын загварчлалаас харахад энэ удаагийн систем нь халуун орны шуурганд байдаг дулаан голч бүхий шинж чанарыг түр зуур олж авах магадлалтай байгаа юм.
Шуурганы замнал болон үргэлжлэх хугацаа нь тодорхойгүй байгаа нь тухайн бүс нутагт үзүүлэх нөлөөллийг урьдчилан таамаглахад хүндрэл учруулж байна. Компьютерын загварууд нь шуурга эрэгт хэр ойртохыг бүрэн дүүрэн зөвшилцөөгүй байгаа бөгөөд эрэгтэй ойрхон удаашрах тусам салхи, хур тунадасны хэмжээ эрс нэмэгдэх эрсдэлтэй.
Энэ жил Атлантын далайд хар салхины идэвхжил түүхэнд байгаагүй бага буюу хэвийн түвшнээс 10 хувь хүрэхгүй байгаа нь “Эль-Ниньо” үзэгдэлтэй холбоотой байж болзошгүй гэж судлаачид тайлбарлаж байна. Цаашид “Эль-Ниньо” хүчээ авах тусам АНУ-ын өмнөд хэсгээр шуурганы идэвхтэй замнал үүсэж, эргийн бүсэд хүчтэй шуурга давтагдах нөхцөл бүрдэж болзошгүй юм.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A powerful nor’easter developing this week will bring wicked winds, rough surf, and heavy rains to coastal communities from North Carolina to Nova Scotia.
These types of storms are more synonymous with mid-winter than mid-fall. And true to form, this storm is a little different. It won’t drop snow or ice like a classic winter nor’easter. In fact, this system may bring a tease of tropical weather to an Atlantic basin that’s been devoid of hurricane activity so far this year.
An Impactful Nor’easter for the East Coast
Nor’easters are special types of low-pressure systems that earn their name from the fierce northeasterly winds that can lash coastlines.
The seed that’ll grow into this weekend’s nor’easter started developing on Wednesday a few hundred miles off North Carolina’s Outer Banks. The system will meander toward New England into this weekend before slowly winding down into early next week.
Forecasters expect strong, persistent winds to hit coastal locations from North Carolina to Nova Scotia. The strongest gusts will buffet New England through Friday and Saturday, when winds may reach 60 to 70 mph.
Communities throughout the region can expect coastal flooding, beach erosion, life-threatening rip currents, and dangerously rough surf. Isolated power outages are possible. Flight delays at New York’s and Boston’s airports are also likely due to blustery winds and rain.
Computer models still don’t entirely agree on how close to the coast this storm will track, or how long it’ll linger in the area—both factors that are crucial to determining exact impacts. A slower track closer to the coast will plaster the region with stronger winds and heavier rainfall than a faster path or one that keeps the center of the storm farther out to sea.
Nor’easters Are Common in Late Fall and Winter
Nor’easters are most common between October and April as powerful jet streams sweep across North America. It’s unusual for such a potent nor’easter to develop this early in the season.
Nor’easters are considered non-tropical—or as meteorologists call them, extratropical—systems that typically draw most of their energy from intense upper-level winds. That’s different from hurricanes, which tend to feed on warmer-than-normal oceans. But low-pressure systems exist on a spectrum that sometimes makes it difficult to neatly define them as tropical or extratropical, and this storm is a prime example.
A Tropical Connection
Some computer models suggest that this week’s nor’easter may acquire some tropical characteristics as it intensifies off the Northeast coastline. Fully extratropical systems feature cold air throughout the entire core of the storm. This nor’easter, on the other hand, may briefly develop a shallow warm core, a phenomenon found in tropical storms and hurricanes. Cloud structure, the storm’s overall wind field, and thunderstorm activity near its center are other tropical characteristics to watch out for.
Even though it’s not likely to earn a name as a hurricane would, it’s important for residents throughout the region to pay attention to the threat of flooding, wind damage, and power outages.
It’s strangely fitting that a nor’easter may prove to be the most hurricane-like non-hurricane we’ve seen across the Atlantic basin this season. We’re now past the peak of hurricane season and the year remains historically quiet. Tropical activity here is running at less than 10 percent of normal for this point in the year. This is also the latest the season has gone without producing a hurricane since the satellite era began in 1966. A quiet hurricane season is a hallmark of an El Niño, when hot waters in the tropical Pacific create conditions in the atmosphere unsuitable for tropical storms to form in the Atlantic.
But winter is a different story, and this week’s storm is also a potential preview of what’s to come as El Niño gains strength. Strong El Niño events tend to influence an active storm track across the southern US during the cooler months, which may in turn lead to more coastal storms along the Eastern Seaboard.
