December 13, 2015 - UNITED STATES - A very mild weather pattern by December standards has
engulfed a large swath of the Lower 48 states, setting hundreds of
record highs and record-warm daily lows. The warmth has been so
incredible that several cities in the Midwest and Northeast have set
daily record highs during the morning hours this weekend.
According
to preliminary data from NOAA's National Centers for Environmental
Information (NCEI), at least 574 record daily highs were tied or broken
across the U.S. during the first 10 days of December, representing about
2.6 percent of the 21,600 daily high-temperature reports received from
more than 3,000 locations. By comparison, just 88 daily record lows were
set in the same time frame.
That
574-to-88 ratio is likely to become even more imbalanced as additional
reports are processed for Thursday, Friday and Saturday and as
widespread warmth grips the nation, squeezing out the possibility of
record lows over most of the Lower 48. In fact, on Sunday record highs
may be threatened for 20 percent of all weather observation sites in the
Lower 48.
Temperatures will soar up to 30 degrees
above average into Monday, setting even more records as the mild air
spreads to the East Coast. Below are the forecast details and a recap of
the records so far.
Cold Air Stays Bottled Up North
As
we start meteorological winter, which runs from Dec. 1 through Feb. 29,
true arctic air remains locked up in extreme northern Canada, well to
the north of the U.S. border and even well north of all the major
Canadian cities.
 |
Current Canada/Northern U.S. Temperatures:
The white line denotes the approximate freezing line (32 degrees Fahrenheit, 0 degrees Celsius). Note in this December warm spell it extends well into Canada. |
While December
is early in the winter season, it is quite common for chunks of
bitterly cold air to reach the U.S. during the first half of the month.
Although some cooler air has reached the western states, it is what meteorologists call a maritime polar
air mass. This air mass is moving in from the northeastern Pacific
Ocean and Gulf of Alaska, whose unfrozen waters have added some warmth
and moisture to the air, moderating its chilly bite.
As
the coldest air still remains locked up in northern Canada, the result
will only be a drop to near or slightly below average in terms of
temperatures in the West and adjacent Plains through early week. The
eastern half of the nation will see temperatures trend closer to average
late in the week ahead and next weekend.
December "Spring Fever" Continues
 |
Forecast Highs Compared to Average:
Darker shades of orange and red correspond to areas that are forecast to see temperatures the farthest above average for the day indicated. |
High
temperatures will remain 10 to 30 degrees above average for many
locations in the East through midweek, setting numerous daily record
high temperatures.
Some areas are seeing low
temperatures that are warmer than their average high temperatures, and a
few places may experience some of the mildest low temperatures on
record for the month of December. Numerous daily record warm low
temperatures will likely fall by the wayside in the eastern two-thirds
of the country.
As mentioned earlier, the warmth has
been so impressive, that many stations broke daily record high
temperatures Saturday morning and again Sunday morning.
Paducah,
Kentucky, reached 68 degrees before 1 a.m. Saturday, quickly breaking
their record high for the date before peaking at 73 degrees in the
afternoon. Other stations that had already reported record highs by 9
a.m. EST Saturday included Cincinnati and Dayton in Ohio. On Sunday
morning, New York City, Milwaukee, Toledo, Ohio, Flint, Michigan,
Moline, Illinois, Dubuque, Iowa, and Cedar Rapids, Iowa, were among some
of the cities that had already set record highs prior to noon. See
below for a more complete listing of record highs and record warm lows.
Through
Monday morning, temperatures are not expected to drop below the
freezing mark for most areas east of the Mississippi River, with the
exception of parts of northern New England.
 |
Forecast Lows This Weekend |
Daily
record high temperatures will be threatened across a large area mainly
along and east of the Mississippi River again on Sunday. Some 20 to 30
percent of all weather observation sites may set records, likely marking
the peak of this warm spell in terms of intensity and geographic
extent. Several more records will be threatened along the East Coast
Monday.
Here are the details:
Sunday's Potential Record Highs:
- How many potential records? Over 70 locations among the 236 major weather observation sites in the Lower 48 will threaten daily record highs.
- Which regions will be affected? Some 20 states may be affected from Iowa and the Great Lakes states to Georgia, as well as over parts of the Northeast.
- Potential Cities (record to beat is in parentheses): Atlanta (73 degrees) | Philadelphia (65 degrees) | Montgomery, Alabama (80 degrees) | Detroit (60 degrees)
Monday's Potential Record Highs:
- How many potential records? Over 40 locations among the 236 major weather observation sites in the Lower 48 will threaten daily record highs.
- Which regions will be affected? Some 17 states may be affected from the Northeast to Florida.
- Potential Cities (record to beat is in parentheses): Columbia, South Carolina (79 degrees) | Buffalo, New York (64 degrees) | Orlando (86 degrees) | Philadelphia (69 degrees) | Providence, Rhode Island (59 degrees)
 |
Forecast Highs Compared to Average |
 |
Forecast Highs Compared to Average
|
So, how long will this last?
Temperatures
will remain well above mid-December averages generally east of the
Mississippi River through Thursday until cold air bottled up in the West
finally is able to spread farther east the second half of the week
ahead.
Parts of the Plains and Midwest should see temperatures
fall back to near seasonable levels by Thursday and Friday. The wait for
more typical December temperatures may be even longer for the East
Coast.
December Record Highs Broken So Far
Below is a look at the records set so far from this December warmth by day.
Saturday, Dec. 12: Record-breaking
warmth reached much of the eastern third of the country, where daily
record highs were set at Tupelo, Mississippi (78 degrees), Cape
Hatteras, North Carolina (73 degrees), Paducah, Kentucky (73 degrees),
Evansville, Indiana (72 degrees), Salisbury, Maryland (72 degrees),
Cleveland, Ohio (70 degrees), Indianapolis, Indiana (70 degrees), Fort
Wayne, Indiana (69 degrees), Akron, Ohio (68 degrees), Lexington,
Kentucky (68 degrees), Trenton, New Jersey (68 degrees), New York City,
LaGuardia Airport (66 degrees), New York City, JFK Airport (64 degrees),
and Detroit, Michigan (63 degrees).
Dallas-Fort Worth International Airport set a record warm low temperature for the entire month of December at 70 degrees.
Daily
record warm low temperatures for Dec. 12 were set in many other
locations including New York City (55 degrees), Newark, New Jersey (48
degrees), Louisville, Kentucky (62 degrees), Paducah, Kentucky (65
degrees), and Columbus, Ohio (56 degrees).
Friday, Dec. 11: Unusually
warm weather prevailed across much of the central and eastern U.S.,
where daily record highs were set at San Angelo, Texas (87 degrees),
Houston's Hobby Airport (82 degrees), Wichita Falls, Texas (81 degrees),
Shreveport, Louisiana (81 degrees), Mobile, Alabama (78 degrees),
Roanoke, Virginia (72 degrees), Rochester, New York (62 degrees) and
Sault Ste. Marie, Michigan (47 degrees), among other locations. Record
highs were also set in Toronto, Ontario (14 degrees Celsius - 57.2
degrees Fahrenheit) and Ottawa, Ontario (13.5 degrees Celsius - 56.3
degrees Fahrenheit).
Thursday, Dec. 10: More
records were broken or tied across the nation's heartland, including
daily record highs at Madison, Wisconsin (56 degrees), and Green Bay,
Wisconsin (54 degrees). Rockford, Illinois, hit 57 degrees, tying its
record high for the date.
Wednesday, Dec. 9: Record
warmth impacted parts of the Plains, where daily record highs included
Oklahoma City (74 degrees) and Topeka, Kansas (70 degrees). Minot, North
Dakota, hit 62 degrees, tying the daily record and marking its warmest
December day since 1939.
Tuesday, Dec. 8: The
Northwest saw more record warmth on Tuesday. Seattle-Tacoma Airport set
a new daily record high for Dec. 8 of 60 degrees, beating the old
record of 59 degrees in 1957. Several other locations in Washington
state also set daily record highs, including Spokane, which tied its
daily record of 56 degrees. In Oregon, both Portland (62 degrees) and
Eugene (62 degrees) set daily record highs Tuesday.
Several
daily record highs for Dec. 8 were also set in the Plains Tuesday,
including Minot, North Dakota (54 degrees - tie), Lincoln, Nebraska (61
degrees - tie), and Russell, Kansas (67 degrees).
A
number of record warm low temperatures were also set for Dec. 8 on
Tuesday. Stanley, Idaho, tied its record for any December day with a
balmy low of 35. Others included Livingston, Montana (44 degrees),
Billings, Montana (43 degrees), Sheridan, Wyoming (36 degrees), Salem,
Oregon (59 degrees), and Eugene, Oregon (57 degrees). Eugene beat its
old daily record warm low for Dec. 8 by a whopping 10 degrees.
Monday, Dec. 7: Redmond,
Oregon, soared to 71 to set a new all-time record high for the month of
December. The previous record was 67 on Dec. 1, 2008. Monday's high
also crushed its daily record by a margin of 13 degrees.
Redmond
also broke its all-time record-warm daily low for the month of December
with a low of 50 Monday, breaking the previous record of 48 set Dec.
10, 2004.
Portland, Oregon, set a new record high of 63
degrees on Monday, as well as a record warm low temperature of 46
degrees. Both of these were recorded at Portland International Airport.
A
smattering of record highs also occurred across the northern Rockies
and Upper Midwest. Impressively, the Grand Portage Ranger Station in the
far northeast corner of Minnesota – with 120 years of weather records
in the books – reached 50 degrees, crushing the daily record of 43 and
setting an all-time record for its latest 50-degree day on record. The
site had only previously reached the 50s on two occasions in December –
51 degrees on Dec. 2, 1962, and 52 degrees two days later.
The
appropriately-named town of Max, North Dakota, had its warmest daily
low on record for the month of December, only dipping as low as 38. The
previous record of 35 had just been set two days earlier; that, in turn,
beat the record of 34 from Dec. 29, 1999. Records in Max have been kept
for 86 years.
Saturday and Sunday, Dec. 5-6: On
Saturday, International Falls tied its record warmest low temperature
for the month of December, only dipping to 36 degrees just before
midnight. The city set a new daily record high of 45 degrees on Sunday.
The
cooperative observer near Ladysmith, Wisconsin, reported a high of 46
Sunday – crushing the daily record of 40 in an impressive 114-year
period of recordkeeping.
An additional
fourteen daily record highs were set in Manitoba Saturday and Sunday,
including Emerson (7.1 degrees Celsius/44.8 degrees Fahrenheit on
Sunday) where records date back to 1877.
In
Oregon, Redmond hit 63 and Roseburg hit 61, both daily record highs for
Saturday. Redmond hit 63 again Sunday, setting another daily record.
Friday, Dec. 4: At
least 16 Canadian cities set daily record highs, particularly in
Manitoba, where the city of Morden, southwest of Winnipeg, soared to
14.2 degrees Celsius (about 57.6 degrees Fahrenheit).
Highs reached the freezing mark as far north as
Thompson, Manitoba on
Friday (roughly 55 degrees North latitude, about 470 miles north of
Winnipeg). The average high on December 4 there is -13.8 C (7.1 F). Just
a bit farther northeast of there on Saturday, Gillam, Manitoba, reached
the freezing mark which also was a new daily record (0.3 C / 32.5 F).
In
the U.S., both Marquette, Michigan (50 degrees at the NWS office in
nearby Negaunee Township), and International Falls, Minnesota (45
degrees), tied their daily record highs Friday.
Thursday, Dec. 3: Only
a few record highs were set at places with long-term records. Three
were in Florida, including 85 at Fort Lauderdale Beach; one was in
Washington, where Bellingham hit 62.
Wednesday, Dec. 2: Charleston,
South Carolina, and Wilmington, North Carolina, each hit 80 degrees to
break daily record highs. On the opposite side of the country, a high of
60 was good for a daily record in Bellingham, Washington.
Tuesday, Dec. 1: A
handful of locations in Florida and south Alabama set daily records,
including a high of 89 near Avon Park, Florida, where records have been
kept for 121 years.
What Effects Will This Warmth Have?
As
a result of the jet stream staying north of the U.S. frequently
throughout November, parts of the Northeast and Mid-Atlantic have
remained rather mild and snowless recently. Philadelphia
saw its second warmest November on record in 2015, and made it through
the autumn to the start of December without a freeze for the first time
since 1939.
For Buffalo, New York,
it was the seventh warmest November on record. Buffalo has also yet to
see accumulating snowfall this season, marking the longest the city has
gone in a snow season without receiving its first measurable snow.
The
lack of snowfall and nights below 32 degrees means a tough start for
ski resorts in parts of New England and the Appalachians. Over the Great
Lakes, on the heels of record late-season ice into spring 2015, lake ice formation may be significantly delayed.
Interestingly
enough, a delay in freezing of the lakes could support a later
lake-effect snow season, as colder air moving over warmer lake water can
lead to the development of heavy snow bands into early winter. This,
however, depends on the ability of substantial moisture to coincide with
sufficient cold air, something that has struggled to happen so far this
season.
It is not just the northeastern quarter of the country that has escaped the bulk of winter’s fury to date.
Florida, in particular, has been on quite a stretch for above normal temperatures. In November, Naples and Fort Lauderdale recorded their warmest November on record. For Miami and West Palm Beach, it was their second warmest November on record.
Fargo, North Dakota
has reached 40 degrees or higher on 260 days so far in 2015. Dating
back to 1942, the record is 261 days in 2012, but December 2015 could
push them over the edge before the month is over.
What About Last Winter?
December
2014 was also a warmer than average month for much of the country.
Despite that happening, winter took a fast turnaround in parts of the
Northeast.
The pattern changed
very quickly in the winter of 2014-15 with record-setting snows hitting
parts of New England in January in February.
There are some differences between this winter and last winter, particularly with the strong El Nino currently in place.