After focusing its wrath on New England for three weeks, winter is about to start expanding its reach. A packet of upper-level energy diving from the Canadian Arctic into the eastern U.S. this weekend will be accompanied by a strong surface high racing southward. The contrast in pressure between this high and the next powerful nor’easter off the New England coast will fuel an expansive area of howling northwest winds and dangerous cold. From northern Ohio across western New York, Sunday could be the coldest day recorded in at least 20 years and the coldest February day in many decades. This area is renowned for its snowy winters, but the same Great Lakes responsible for the snow also help buffer the region somewhat from the most extreme cold that’s found in the Upper Midwest and New England. Here are some NWS-predicted highs for Sunday, along with relevant records. Note that some cities could set daily highs for Sunday just after midnight on Saturday night, in which case the the numbers may end up less cold than shown here.Cleveland, OH: 3°F
Last time a high was this cold: 2°F on Jan. 16, 2009
Lowest high for any day on record: –5°F on Feb. 9, 1899Buffalo, NY: –2°F
Last time a high was this cold: –2°F on Jan. 17, 1982
Lowest high for any day on record: –3°F on Feb. 10, 1899 and Feb. 11, 1885Rochester, NY: –2°F
Last time a high was this cold: –4°F on Jan. 17, 1982
Lowest high for any day on record: –4°F on Jan. 17, 1982New York Central Park, NY: 17°F
Last time a high was this cold: 17°F on Jan. 22, 2014
Lowest high for any day on record: 2°F on Dec. 30, 1917
Temperatures are expected to dip to near or below 0°F across the New York metro area on Sunday night. The last time Central Park hit zero was on January 27, 1994. A shot of light to moderate snow will hit the coastal region from Philadelphia northward Saturday night and Sunday morning, with some heavier bursts possible in localized bands. The big concern is blowing snow and extremely high wind, with gusts to 60 mph possible (see Figure 1). Snow amounts will be much heavier from the Boston area northeastward. The NWS has posted blizzard watches from Saturday night through Sunday night for coastal counties from northern Massachusetts through Maine. Many areas will see a foot or more of new snow on top of 20 – 40” or more of existing snowpack, exacerbating already-serious impacts on roofing and infrastructure. Blowing snow will be a huge problem. The largest accumulations should be in southeastern Maine: 1 -2 feet are predicted to fall atop Bangor’s current snowpack of 45”. One station to watch for extreme wind this weekend is New Hampshire’s Mount Washington Observatory, which has already gusted to 89 mph
at 9:45 AM EST on Friday morning.
Another winter storm appears likely to affect a much broader swath of the nation early next week, with a patchwork of snow, freezing rain, and sleet developing from Oklahoma and Texas to the Carolinas. This system may congeal into yet another bombshell nor’easter later in the week, perhaps accompanied by another shot of frigid air on par with this weekend’s, although uncertainty remains high at this point. Temperatures in New York may not reach the freezing mark for at least the next week.Figure 1.
The GFS model forecast issued at 0000 GMT Friday, 13 February, projects a powerful coastal low just east of Boston (minimum pressure contour of 976 mb) and a strong surface high north of Lake Huron (maximum pressure contour of 1042 mb) at 1200 GMT (7:00 AM EDT) Sunday, 15 February. The tightly packed isobars (black lines) between the two shows the extreme pressure gradient expected to generate dangerous wind chills across much of the Northeast, with blizzard conditions along the northern New England coast. Image credit: College of DuPage/Next Generation Weather Lab.Severe weather season is at our doorstep
A few thunderstorms could develop on Monday or Tuesday near the cold front plowing into the Gulf Coast, although the threat of severe weather appears minimal. Some of the South’s worst tornadoes have occurred in February, as warm, moist Gulf air surges toward winter storms. Florida and Georgia held their annual severe weather awareness weeks February 2 – 6; Mississippi’s is now under way, and Louisiana and Alabama are slated for next week. It’s been a very quiet year for tornadoes thus far, with only 27 reported nationwide through February 11 compared to a year-to-date average of 68
for the period 2005 – 2014. Figure 2.
One of my favorite books as a child ("Weather: A Golden Guide"] included an illustration of a tornado dipping from mammatus clouds. Photos and videos have since made it clear that mammatus don’t produce twisters, but these clouds still generate a mysterious, ominous beauty. Mammatus are featured in this week’s new WunderPoster
, which can be downloaded in formats suitable for posters or postcards. New posters will be unveiled each week through April.
See the WunderPosters site
and our blog from last week
for more details.Figure 3.
A spectacular field of mammatus on display west of Amarillo, Texas, on June 9, 2014. Image credit: Image credit: wunderphotographer tornadodude