The strong, recurrent Pacific jet stream that’s been delivering massive amounts of rain to California has also been pushing mild Pacific air downslope off the Rockies and eastward, keeping the southern two-thirds of the U.S. absurdly warm for early February. From New Mexico to Virginia southward to the Gulf Coast, trees and shrubs are budding out en masse up to three weeks ahead of schedule (see Figure 1). In Texas, Dallas-Fort Worth recorded its last freezing temperature on January 8. With no freezes expected into at least the last week of the month, there’s a chance that the Jan. 8 reading of 20°F will be DFW’s last freeze of the winter. That would eclipse the earliest final freeze of the season (Feb. 5, 2000), in records extending back to 1899. The February warmth comes after a three-month span that was milder in Texas than any Nov/Dec/Jan period since the 1930s Dust Bowl, according to state climatologist John Nielsen-Gammon
The warm, moist air prevailing along the South has been teaming up with occasional jet-stream intrusions to produce severe thunderstorms, including an unusually large number of tornadoes for the year thus far. This includes six confirmed tornadoes across southeast Louisiana on February 7, with an EF3 twister causing more than 30 injuries and damaging or destroying more than 600 homes in and near East New Orleans (see the detailed National Weather Service survey report
on all six tornadoes). As of February 13, NOAA’s Storm Prediction Center had tallied 163 U.S. tornadoes for the year thus far
, not quite a record but far above average. On Tuesday morning
, NOAA/SPC placed parts of the western and central Gulf Coast under a slight risk of severe weather, with a small enhanced-risk area along the central Texas coast near a large thunderstorm complex that had already produced several tornado reports west of Houston.Figure 1.
An index of the seasonal progress of leafy plants shows conditions 20 days or more ahead of schedule over large parts of the South and Southwest as of Sunday, February 12. Image credit: USA National Phenology Network via @TheresaCrimmins
Spectators watch as a tornado-damaged water tower comes down in Rowlett, TX, on Monday, Feb. 6, 2017. Workers toppled the Dallas-area water tower that was severely damaged during a 2015 tornado outbreak blamed for more than a dozen deaths. Image credit: Vernon Bryant/The Dallas Morning News via AP.Close to the century mark in Oklahoma
While there’s been quite a few ups and downs to the national temperature picture in recent days, with frequent frontal passages, the low temperatures haven’t been all that low and the highs have been unusually high, as noted
by WU blogger Steve Gregory. For the month to date through February 12, NOAA had compiled
a preliminary total of 1207 daily record highs and 10 daily record lows, for a staggering ratio of more than 100 to 1
. It’s a picture in line with recent months: November 2016 had the largest ratio of record highs to lows of any month in modern records
. It’s also consistent with the inexorable effect of human-produced greenhouse gases in boosting temperatures to make record warmth more widespread and extreme than record cold.
One especially strong pulse of warm air jet pushed across the Southern Rockies and into the South from Friday into Sunday. As the already-mild air descended the Rockies, it warmed further due to downslope compression, leading to some eye-popping readings. Several stations in southwest Oklahoma soared into the upper 90s on Saturday. The town of Mangum hit an astounding-for-February 99°F, which tied the state record for any winter month (Dec/Jan/Feb) that was set at Arapaho on Feb. 24, 1918.
Here’s a sampling of the all-time February heat records set over the past several days. In many cases, you have to go to mid-March to find comparable warmth!
Friday 2/10:Wichita Falls, TX: 94°F
(next-earliest reading at least this warm was 98°F on 3/1/2006; records began in 1923)Liberal, KS: 90°F
(next-earliest 90° was 3/11/1989; records began in 1893)Amarillo, TX: 89°F
(next-earliest 89° was 3/10/1989; records began in 1892)Goodland, KS: 87°F
(next-earliest 87° was 3/10/1989; records began in 1895)Denver, CO: 80°F
(next-earliest reading at least this warm was 81°F on 3/16/2015; records began in 1872). A cooperative observing station at the site of Denver’s former Stapleton Airport, where official readings were taken until the mid-1990s, reported 83°F.
Saturday 2/11:Lubbock, TX: 91°F
(next-earliest reading at least this warm was 95°F on 3/11/1989; records began in 1911)
Sunday 2/12:Norfolk, VA: 82°F
(ties all-time monthly high set on 2/4/1890 and other dates; records began in 1874)Figure 3.
High temperatures across Oklahoma on Saturday, February 11, were similar to readings one might expect in early July. Image credit: Oklahoma Mesonet, @okmesonet
Temperature departures from average for the period February 1-12, 2017. The warm anomalies will likely persist, as models are calling for continued milder-than-average weather over most of the nation through late February. Image credit: NOAA/CPC Climate Prediction Center
.Cold enough to ski; too mild to ice-climb
The abnormally mild February hasn’t put a dent in Colorado’s bang-up ski season. The highest slopes are still more than cold enough to support a healthy snowpack even with above-average temperatures. At opensnow.com, Joel Gratz noted
that the statewide snowpack as of Sunday, February 12, had already matched the level reached during the early-April peak of an average year. “What an awesome season so far with more to come!” exclaimed Gratz. Meanwhile, at Colorado’s lower elevations, those hankering for winter recreation felt the pinch of unseasonal warmth. The state’s Ouray Ice Park climbing venue was forced to close for the season
on Friday, February 10, a full month earlier than average
. “While we still hold a glimmer of hope for this season at the Park, that is fading fast,” said the park in a plaintive online statement
.Surges of warmth continue to funnel into high Arctic
The strong jet streams crossing the U.S. of late have spun up several powerful Northeast snowstorms (see embedded video below) and gone on to push very mild, moist air deep into the Arctic. One such spike arrived late last week, with temperatures of 50°F or more above average approaching the North Pole as reported by Capital Weather Gang
and The Weather Network (Canada)
Well downstream from the nor’easter that was slamming eastern New England on Monday, a swath of low-latitude air pushed the temperature at Eyjabakkar, Iceland, up to 19.1°C (66.4°F). If validated, this will rank a full 1°C (1.8°F) above the previous national record for February, set at Dalatangi on Feb. 17, 1998, according to international weather records researcher Maximiliano Herrera. He adds that temperatures in the free atmosphere over central Sweden were analyzed above the freezing mark on Monday at heights of up to 11,000 feet.
Unsurprisingly, the extent of Arctic sea ice
remains at record-low levels for mid-February. Moreover, the extent of Antarctic sea ice is on the brink of setting a record-low value for any time of year. Figure 5.
This year is lagging all other years since records began in 1979 for sea ice extent in February. Image credit: National Snow and Ice Data Center
Smoke billows from a wildfire near Mudgee, Australia, on Monday, Feb. 13, 2017. The fire has consumed more than 5000 hectares (12,350 acres) of bush and grasslands northwest of Sydney. Image credit: New South Wales Rural Fire Service via AP.Eastern Australia blisters in all-time record heat
Another swarm of heat records invaded eastern Australia, where a brutal summer is unfolding. Port Macquairie, where records have been kept since 1910, broke its all-time record for any date on Sunday with a scorching high of 46.6°C (115.9°F). That’s an incredible 3.3°C (5.9°F) above the city’s previous all-time high. “You don’t break [100-plus-year] records by 3C,” noted Andrew Watkins (@windjunky)
. An even older all-time high fell at Toowoomba, Queensland, where a maximum of 40.3°C (104.5°F) was the first reading above 40°C (104°F)
since records began at Toowoomba way back in 1869. Fire danger across parts of tinder-dry New South Wales has been at near-record levels, and bushfires have already swallowed up dozens of homes
, with more hot weather returning late this week.
Bob HensonFigure 7.
James Cagney, 13, of Portland walks on Noyes Street on his way to shovel a neighbor's driveway on Monday, Feb. 13, 2017. A major nor’easter dumped 1 to 3 feet of snow
across parts of Maine. South of the intensifying low, wind gusts howled at 50-60 mph or more from the mid-Atlantic to southern New England. Image credit: Derek Davis/Portland Press Herald via Getty Images. Video 1.
Annotated GOES-16 imagery of the winter storm that pummeled eastern New England and the Canadian Maritimes on Monday, February 13. Image credit: @NOAASatellites