An Extreme Pre-Christmas Winter Pattern Across U.S Following A Record Warm Fall

Written by on December 13, 2016 in United States of America, Winter 2016/17 with 0 Comments

There’s a lot going on, so thought I would share these interesting posts from weather.com

Back-to-Back Arctic Blasts Will Send Midwest, Northeast into a Deep Freeze Through the Weekend

By Chris Dolce
Published Dec 13 2016 01:43 PM EST
weather.com

Story Highlights

Two more shots of arctic air will sweep through the nation’s northern tier into this weekend.

Temperatures will be dangerously cold in some areas, with wind chills in the teens, 20s and 30s below zero.

Some locations may flirt with their coldest December temperatures in several years.

Back-to-back rounds of arctic air will grip parts of the nation’s northern tier through this weekend, continuing what has been an icy cold start to December in many cities.

(MORE: 5 Things to Know About Arctic Cold Fronts and the Plummeting Temperatures They Produce)

The first intrusion of arctic air this week has already made its way into the Plains and Upper Midwest, and will take aim on the Northeast by late week. Another round of shivering temperatures may then plunge south of the Canadian border and into the north-central states by this weekend on the heels of Winter Storm Decima which will move through that region.

(MORE: Another Snowstorm in the Midwest)

Two rounds of arctic air will sweep into the nation’s northern tier this week into the weekend. 

Some locations could see their coldest December temperatures in several years, and a few record lows may be threatened. Wind chills will may make it feel like the teens, 20s or 30s below zero in the Midwest at times during the week ahead.

(MORE: Current Wind ChillsHow is the Wind Chill Calculated?)

Forecast: Arctic Cold Round #1

On Tuesday morning, subzero lows were recorded as far south as northern Iowa and northern Nebraska. Wind chills dropped as low as minus 36 degrees in Winthrop, Minnesota.

Great Falls, Montana, recorded its ninth straight day in a row with subzero lows on Tuesday morning. That is longest such streak there since February 1996.

Here is an overview of the expected highs and lows through the workweek followed by some perspective on the last time we saw temperatures this cold in December for a few cities.

Current Temperatures

Current Temperatures

Forecast Highs

  • Midwest: Highs from Montana to the Great Lakes will generally be in the single digits and teens in most locations with this first round of cold air through Thursday. At times it will be 10-25 degrees below average for this time of year.
  • East: The coldest high temperatures will sweep through the Eastern Seaboard Thursday-Friday with daytime readings 10-25 degrees below average. Temperatures will not rise out of the 20s along the Interstate 95 corridor from Boston to Washington, D.C. on Thursday. Interior Northeast cities may not get out of the teens.
  • Cities: Bismarck, North Dakota | Chicago | Minneapolis | Boston | New York
Forecast Highs

Forecast Highs

Forecast Lows

  • Midwest: By Thursday and Friday morning, Chicago, Milwaukee and Detroit could see temperatures plunge to near or below zero, which is 20-30 degrees below average for mid-December. Parts of North Dakota and Minnesota may see lows in the double digits below zero Thursday morning, including Minneapolis. Wind chills in the teens, 20s and 30s below zero will impact the northern Plains and Upper Midwest through midweek.
  • East: Friday morning looks to be the coldest for many Northeast cities with lows 20-30 degrees below average. Single digits above and below zero are expected in parts of Upstate New York, northern/western Pennsylvania and New England. Wind chills will be single digits, teens and even a few 20s below zero across the interior Northeast and New England Friday morning
  • Cities: Billings, Montana | Detroit | Milwaukee | Fargo, North Dakota | Buffalo, New York | Pittsburgh | Washington, D.C.
Forecast Morning Lows

Forecast Morning Lows

Cold Perspective

  • Will any record lows be set? Widespread daily record lows are not forecast, but some locations could flirt with records on Friday morning. This includes (record to beat is shown): Detroit (minus 3 degrees), Newark (10 degrees) and Providence (3 degrees).
  • Chicago and Milwaukee: Thursday or Friday could feature the first subzero December temperatures in those cities since Dec. 24, 2013 and Dec. 30, 2013, respectively. Thursday could also be the first December day since 2008 that the high fails to rise out of the single digits in Chicago.
  • Detroit: Friday morning could be the first subzero December reading since Dec. 25, 2004 (minus 4 degrees).
  • Boston: A low of 8 degrees or colder would be the lowest official December temperature in the city since 2004.
  • Pittsburgh: The first single digit December low temperature since Dec. 31, 2009 (9 degrees) is possible Friday morning.

Forecast: Arctic Cold Round #2

The second plunge of arctic air will begin seeping south of the Canadian border and into the northern Plains by Friday. That cold air will spread eastward across the Midwest during the weekend ahead.

This weekend’s temperatures could be the coldest we’ve see so far this month in some locales, but given this several days away, uncertainty remains in the details.

(MAPS: 10-Day Forecast)

  • Lows: Temperatures in the teens and 20s below zero will infiltrate areas from Montana to the Dakotas and the upper Mississippi Valley this weekend. In some locations, this will be 20-40 degrees below mid-December average lows. Single digits below zero may surge into the Front Range of Colorado, Kansas, northern Missouri and northern Illinois.
  • Highs: Afternoon readings may not rise above zero in the northern Plains and Upper Midwest this weekend, including Minneapolis and Fargo, North Dakota.
  • This round of arctic air may spread through the Great Lakes and into the Northeast early next week.
Forecast AM Lows This Weekend

Forecast AM Lows This Weekend

Cold Perspective For This Weekend

  • Minneapolis: If the mercury plunges into the 20s below zero, that would be the first time its happened there in December since 1996. The last 20s below zero in the Twin Cities for any month occurred in January 2014.
  • Bismarck, North Dakota: Saturday’s highs may be in the teens below zero. The last time they recorded a high in the double digits below zero in December was 2008. They haven’t had a high in the teens below zero in any month since January 2010.

Winter Storm Decima to Bring a Cross-Country Mess of Snow and Ice to the West, Midwest and Northeast Into the Weekend

Published Dec 13 2016 10:49 AM EST
weather.com

Story Highlights

Decima will bring snow and some ice across the country later this week.

This system arrives in the Northwest on Wednesday, then spreads its wintry mess east into the weekend.

Some areas affected by Winter Storm Caly last weekend will see more snow from Decima

Winter Storm Decima – prounced DEH-si-mah – is poised to deliver another cross-country mess of snow, strong winds and some ice impacting a large swath of the nation into the upcoming weekend.

(MORE: The Science Behind Naming Winter Storms | 2016-2017 Winter Storm Names)

Decima follows on the heels of Winter Storm Caly, which blanketed the U.S. with wintry weather from coast-to-coast last Thursday into Monday.

(MORE: Arctic Cold Dominates Northern States)

Decima will get its start as a southward plunge of the jet stream, originating from the Gulf of Alaska, begins to plow into the western United States.

Late-Week Setup

Cold air is in place across the Midwest and East with high pressure in store. A storm system sweeping into the western states then moves eastward into the cold air, making wintry weather possible.

Winter storm watches are already posted for a sizable swath of the West, from Oregon and California’s Sierra to parts of Montana and Wyoming.

Current Winter Alerts

Current Winter Alerts

Energy in that jet-stream dip will eventually spawn an area of surface low pressure in the Plains, which will track northeastward with time through the central and eastern states. Moisture from that system will overlap with cold air to its north and from high pressure in the eastern states to make conditions ripe for the potential of snow, sleet and freezing rain in a large area.

(MORE: Winter Storm Central)

Below is a general overview of the timing and impacts from Decima at this time. Keep in mind, however, that since we are still several days away, parts of the forecast remain uncertain and subject to revisions.

Wednesday-Thursday

Wednesday's Forecast

Wednesday’s Forecast

Areas shown in darkest teal have the best chance of snow. Areas in pink may see either rain or snow. Areas in purple may see sleet or freezing rain.

  • Snow will spread into the West Wednesday from parts of Oregon to the Rockies of Colorado.
  • The larger-scale jet-stream dip will then plow into the West Coast starting Thursday. Snow is expected from California’s Sierra Nevada north and eastward into Oregon, southeast Washington, Idaho, Montana, northern Nevada, Utah and the Colorado Rockies.
  • Some initial cold air trapped west of the Cascades could set up parts of the Portland and Seattle metro areas with more snow late Wednesday into Thursday.
  • Light snow begins to spread into the northern Plains Thursday.
  • Cities: Boise, Idaho | Butte, Montana | Jackson Hole, Wyoming | Tahoe City, California

Friday

Friday's Forecast

Friday’s Forecast

Areas shown in darkest teal have the best chance of snow. Areas in pink may see either rain or snow. Areas in purple may see sleet or freezing rain.

  • Decima will expand its reach from the northern Plains into the upper Midwest and Great Lakes Thursday night through Friday.
  • Snow, possibly heavy in spots, and strong winds are possible in those areas, with the strength of the winds dependent on how intense a developing area of surface low pressure becomes. Blowing snow could create low visibility and dangerous travel conditions.
  • As milder air overruns cold air near the surface of the earth, some freezing rain or sleet could affect the central Plains and mid-Mississippi Valley.
  • Snow will also continue in the Rockies, Great Basin and southern Sierra, and could be heavy in spots.
  • Cities: Green Bay, Wisconsin | Minneapolis | Rapid City, South Dakota | Salt Lake City

(MORE: Extended Forecast Maps)

Friday Night-Saturday

Saturday's Forecast

Saturday’s Forecast

Areas shown in darkest teal have the best chance of snow. Areas in pink may see either rain or snow. Areas in purple may see sleet or freezing rain.

  • Moisture from Decima will overrun cold air from a retreating area of high pressure in the East. This would result in some sleet or freezing rain affecting parts of the Ohio Valley, Appalachians, adjacent piedmont and mid-Atlantic states.
  • Meanwhile, snow will spread east from the upper Midwest into parts of the Northeast.
  • A second area of snow will stretch farther west into the central Plains and Front Range of the Rockies.
  • Cities: Buffalo, New York | Milwaukee | Pittsburgh | Denver

How Much Snow, Ice?

West

  • The heaviest accumulations are likely to be in the Oregon Cascades (and adjacent eastern foothills), Sierra, high country of central Idaho, Tetons and Wind River range of Wyoming and, eventually by the weekend, parts of the Rockies of Colorado and Wasatch of Utah.
  • Some accumulations are also expected in lower elevations, such as the Willamette Valley of Oregon, Snake River Plain of Idaho, the Salt Lake Valley, the High Plains of Montana and Wyoming, and Front Range of Colorado.
  • In parts of the Willamette Valley, some sleet or freezing rain may mix in, at times.
West Snowfall Forecast

West Snowfall Forecast

Central/East

  • While it is too soon for precise snowfall forecasts, a swath of at least 6 inches of accumulating snow is possible from the Plains of South Dakota and northern Nebraska through the Great Lakes and parts of the interior Northeast Friday into the weekend.
  • Some accumulations of ice and sleet are possible in parts of the mid-Mississippi Valley, Ohio Valley, Appalachians, adjacent piedmont and Northeast Friday into Saturday. This does not appear to be a major ice storm, but some icing of trees and overpasses may occur.
  • Some lighter snow accumulations are possible in the cold air as the storm exits from the central Plains to the Ohio Valley and Northeast Saturday and Sunday.
Snowfall Outlook

Snowfall Outlook

While it is too far out in time to specify exact forecast snowfall totals, areas in the purple and pink contours have a higher chance at heavy snowfall. Note some areas in the lake snowbelts will first have heavy lake-effect snow later this week.

Once again, there will be changes to this forecast in the days ahead, and more details will follow. Check back with weather.com for updates.

Incidentally, Decima was one of the Fates in Roman mythology.

Significant Lake-Effect Snow Expected This Week; Feet of Snow Likely

By Brian Donegan
Published Dec 13 2016 02:58 PM EST
weather.com

Story Highlights

Lake-effect snow will develop Tuesday in the western Great Lakes and Wednesday in the eastern Great Lakes.

Strong, gusty winds may lead to whiteout conditions in the most intense snow bands.

Snow totals over two feet are likely in some localized areas.

After up to three feet of snow buried parts of the Great Lakes and Northeast states last week, the next round of significant lake-effect snow looms in the coming days.

The coldest air mass of the season will engulf this region during the second half of the week, setting the stage for a multi-day siege of lake-effect snow.

(MORE: Back-to-Back Arctic Blasts Will Send Midwest, Northeast into a Deep Freeze Through the Weekend)

Lake-effect snow warnings have been issued in New York state for the counties east of Lakes Ontario and Erie, including the Buffalo metro area. A lake-effect snow advisory has been issued for some other portions of western New York, including Rochester.

Parts of northwest Pennsylvania and northeast Ohio, including Cleveland, are under lake-effect snow watches.

A blizzard warning is in effect for the Keweenaw Peninsula of Upper Michigan due to strong, gusty winds creating frequent whiteout conditions.

Current Winter Weather Alerts

Current Winter Weather Alerts

Lake-Effect Snow Forecast and Impacts

Organized lake-effect snow will begin to develop Tuesday morning in the western Great Lakes. Any significant snow in the eastern Great Lakes should hold off until Wednesday after a cold front pushes through the region, dropping the temperatures and shifting winds from a more westerly direction.

Lakes Erie and Ontario will likely see the highest snowfall totals due to the air picking up moisture from the western Great Lakes before reaching the eastern Great Lakes.

For example, Lake Huron and the Georgian Bay will help “feed” moisture to the snow bands that develop off Lakes Erie and Ontario due to the westerly to northwesterly prevailing winds.

Under this pattern, it’s not uncommon to see snow totals over 30 inches on the Tug Hill Plateau in New York state, east of Lake Ontario. This is due to westerly winds blowing over the longest axis of the lake, as well as the upwind connection with the western Great Lakes. The gradual west-to-east rise in elevation on the plateau also plays a role.

(MORE: The Great Lakes’ Amazing Lake-Effect Snowfall Records)

Snowfall Forecast

Snowfall Forecast

This does not mean snow totals downwind of the other four Great Lakes will be insignificant. There could be over a foot of snow within any persistent bands of lake-effect snow, especially if they remain nearly stationary over a given area for several hours.

While Buffalo and Cleveland may see several inches of snow from this event, it appears the most significant accumulations will stay just south and east of those respective cities.

(FORECAST: Syracuse | Buffalo | Cleveland | Marquette, Michigan)

Strong wind gusts will lead to poor visibility due to blowing and drifting snow, as well as falling snow. Therefore, whiteout conditions are possible in the core of any lake-effect bands that develop this week.

More interestingly, the strong winds could also carry some snow bands very far inland, potentially bringing flurries to the Interstate 95 corridor.

Keep in mind, these intense lake-effect snow bands are notorious for causing car accidents and pileups on highways, due to extremely low visibility and slick, snow-covered roadways. Last Thursday, two separate pileups closed stretches of Interstate 90 near the Ohio-Pennsylvania border, as a lake-effect band dumped heavy snow on the highway.

As high pressure builds across the Great Lakes and Northeast states on Friday, lake-effect snow will fade away, but the weather won’t remain quiet for long.

Winter Storm Decima will impact the region by the weekend, bringing more accumulating snow. For more details on that, click the link below.

(MORE: Another Cross-Country Snowstorm)

Setup for Multi-Day Lake-Effect Siege

An upper-level area of low pressure will set up south of the Hudson Bay in Canada Tuesday into Thursday, spinning frigid westerly to northwesterly winds across the warm Great Lakes – by December standards.

Lake temperatures are still in the 40s, and the air mass will be so cold that intense snow bands will develop, potentially dumping feet of snow, especially east of Lake Ontario, where the bitterly cold air will have the longest fetch, or path of the air across the lake.

(MORE: The Science Behind Lake-Effect Snow)

Midweek Setup for Lake-Effect Snow

Model guidance is suggesting air temperatures 5,000 feet above the ground will drop to minus 20 degrees Celsius (minus 4 degrees Fahrenheit) or colder, and in order for lake-effect snow to form, the temperature difference between the lake and 5,000 feet must be at least 13 degrees Celsius (23 degrees Fahrenheit).

Since lake temperatures are in the 40s, the minus-20-degr

Significant Lake-Effect Snow Expected This Week; Feet of Snow Likely

By Brian Donegan
Published Dec 13 2016 02:58 PM EST
weather.com

Story Highlights

Lake-effect snow will develop Tuesday in the western Great Lakes and Wednesday in the eastern Great Lakes.

Strong, gusty winds may lead to whiteout conditions in the most intense snow bands.

Snow totals over two feet are likely in some localized areas.

After up to three feet of snow buried parts of the Great Lakes and Northeast states last week, the next round of significant lake-effect snow looms in the coming days.

The coldest air mass of the season will engulf this region during the second half of the week, setting the stage for a multi-day siege of lake-effect snow.

(MORE: Back-to-Back Arctic Blasts Will Send Midwest, Northeast into a Deep Freeze Through the Weekend)

Lake-effect snow warnings have been issued in New York state for the counties east of Lakes Ontario and Erie, including the Buffalo metro area. A lake-effect snow advisory has been issued for some other portions of western New York, including Rochester.

Parts of northwest Pennsylvania and northeast Ohio, including Cleveland, are under lake-effect snow watches.

A blizzard warning is in effect for the Keweenaw Peninsula of Upper Michigan due to strong, gusty winds creating frequent whiteout conditions.

Current Winter Weather Alerts

Current Winter Weather Alerts

Lake-Effect Snow Forecast and Impacts

Organized lake-effect snow will begin to develop Tuesday morning in the western Great Lakes. Any significant snow in the eastern Great Lakes should hold off until Wednesday after a cold front pushes through the region, dropping the temperatures and shifting winds from a more westerly direction.

Lakes Erie and Ontario will likely see the highest snowfall totals due to the air picking up moisture from the western Great Lakes before reaching the eastern Great Lakes.

For example, Lake Huron and the Georgian Bay will help “feed” moisture to the snow bands that develop off Lakes Erie and Ontario due to the westerly to northwesterly prevailing winds.

Under this pattern, it’s not uncommon to see snow totals over 30 inches on the Tug Hill Plateau in New York state, east of Lake Ontario. This is due to westerly winds blowing over the longest axis of the lake, as well as the upwind connection with the western Great Lakes. The gradual west-to-east rise in elevation on the plateau also plays a role.

(MORE: The Great Lakes’ Amazing Lake-Effect Snowfall Records)

Snowfall Forecast

Snowfall Forecast

This does not mean snow totals downwind of the other four Great Lakes will be insignificant. There could be over a foot of snow within any persistent bands of lake-effect snow, especially if they remain nearly stationary over a given area for several hours.

While Buffalo and Cleveland may see several inches of snow from this event, it appears the most significant accumulations will stay just south and east of those respective cities.

(FORECAST: Syracuse | Buffalo | Cleveland | Marquette, Michigan)

Strong wind gusts will lead to poor visibility due to blowing and drifting snow, as well as falling snow. Therefore, whiteout conditions are possible in the core of any lake-effect bands that develop this week.

More interestingly, the strong winds could also carry some snow bands very far inland, potentially bringing flurries to the Interstate 95 corridor.

Keep in mind, these intense lake-effect snow bands are notorious for causing car accidents and pileups on highways, due to extremely low visibility and slick, snow-covered roadways. Last Thursday, two separate pileups closed stretches of Interstate 90 near the Ohio-Pennsylvania border, as a lake-effect band dumped heavy snow on the highway.

As high pressure builds across the Great Lakes and Northeast states on Friday, lake-effect snow will fade away, but the weather won’t remain quiet for long.

Winter Storm Decima will impact the region by the weekend, bringing more accumulating snow. For more details on that, click the link below.

(MORE: Another Cross-Country Snowstorm)

Setup for Multi-Day Lake-Effect Siege

An upper-level area of low pressure will set up south of the Hudson Bay in Canada Tuesday into Thursday, spinning frigid westerly to northwesterly winds across the warm Great Lakes – by December standards.

Lake temperatures are still in the 40s, and the air mass will be so cold that intense snow bands will develop, potentially dumping feet of snow, especially east of Lake Ontario, where the bitterly cold air will have the longest fetch, or path of the air across the lake.

(MORE: The Science Behind Lake-Effect Snow)

Midweek Setup for Lake-Effect Snow

Model guidance is suggesting air temperatures 5,000 feet above the ground will drop to minus 20 degrees Celsius (minus 4 degrees Fahrenheit) or colder, and in order for lake-effect snow to form, the temperature difference between the lake and 5,000 feet must be at least 13 degrees Celsius (23 degrees Fahrenheit).

Since lake temperatures are in the 40s, the minus-20-degree air temperatures at 5,000 feet will exceed the temperature difference required for the formation of lake-effect snow.

Follow us

Connect with Mark Vogan on social media to get notified about new posts and for the latest weather updates.

Subscribe via RSS Feed Connect on YouTube

Leave a Reply

Top