The U.S. and European cold blast: blame the NAO

By: Dr. Jeff Masters , 4:00 PM GMT on January 07, 2010

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The Deep South shivered through another frigid morning today, with low temperature records crumbling again over much of Florida. Lakeland hit 27°F, smashing the old record of 34°F; Melbourne hit 28°F, eclipsing the old record of 32°F; and West Palm Beach bottomed out at 37°F, besting the old record of 38°F. The cold wave is being driven by an unusual sharp and persistent kink in the jet stream that is being blocked from moving by a strong ridge of high pressure over Greenland. As a result, an exceptionally strong surface high pressure of 1055 mb over the North Central U.S. is pushing large amounts of cold, Arctic air southwards from Canada. No coldest January temperature records have been set yet from the cold blast, but the 500 largest U.S. cities have been averaging about 11 new daily low temperature records per day the first five days of January, according to the National Climatic Data Center. The cold will ease Friday in the Deep South, but return with a vengeance Saturday night though Monday morning, as another push of cold air descending from Canada promises to bring a cold wave that will approach the December 1989 and January 1977 cold waves in intensity, and may being some new all-time January low temperature records to the South.

Colder in Florida than Alaska and Greenland
The sharp kink in the jet stream has brought record warm temperatures to a few stations in Alaska and the Pacific Northwest this week, making much of coastal Alaska warmer than Florida. Cold Bay, Alaska, set a record high yesterday of 47°F, after recording a low temperature of 30°F. This made Cold Bay warmer than Pensacola, Florida, which had a high of 47°F and a low of 24°F. In fact, most of Florida--including Jacksonville, Tampa, Melbourne, and Tallahassee--recorded lows at or below the 27°F low recorded in Anchorage, Alaska yesterday. The jet stream kink has also brought temperatures more than 30°F above average to Greenland. The temperature in Narsarsuaq, Greenland at 10am EST today was 46°F, far warmer than most of Florida.


Figure 1. Departure of the surface temperature from average for the first three day of 2010 shows much colder than average conditions were present over the Southeast U.S., much of Europe, and Central Asia. Much warmer than average temperatures were present over the Northwest U.S., Greenland, the Arctic, and Southern Asia. A sharp kink in the jet stream was responsible for the temperature anomaly pattern. Image credit: NOAA/ESRL.

Snow in Florida?
It doesn't snow very often in Florida, and the Wikipedia list of snow events in Florida lists only seven such events over the decade of the 2000s. This weekend's cold wave may be able to generate some snow over isolated regions of Central Florida, though it appears that the odds of this happening are less than 30%. The most widespread snowfall in Florida history occurred on January 19, 1977, when snow fell over much of the state, with flurries as far south as Homestead. Snow flurries also fell on Miami Beach for the only time in recorded history.


Figure 2. North Atlantic Oscillation (NAO) index for September 9, 2009 - January 6, 2010 (black line) and forecast from the GFS model (red lines). The NAO index was strongly negative, near -2.0, for much of December and January. Image credit: NOAA/CPC.

The winter cold blast: blame the North Atlantic Oscillation (NAO)
Why has the winter been so cold over Eastern North America and northern Europe? Well, don't blame El Niño. El Niño winters are rarely this cold. Instead, blame the the North Atlantic Oscillation (NAO). The NAO is a climate pattern in the North Atlantic Ocean of fluctuations in the difference of sea-level pressure between the Icelandic Low and the Azores High. It is one of oldest known climate oscillations--seafaring Scandinavians described the pattern several centuries ago. Through east-west oscillation motions of the Icelandic Low and the Azores High,the NAO controls the strength and direction of westerly winds and storm tracks across the North Atlantic. A large difference in the pressure between Iceland and the Azores (positive NAO) leads to increased westerly winds and mild and wet winters in Europe. Positive NAO conditions also cause the Icelandic Low to draw a stronger south-westerly flow of air over eastern North America, preventing Arctic air from plunging southward. In contrast, if the difference in sea-level pressure between Iceland and the Azores is small (negative NAO), westerly winds are suppressed, allowing Arctic air to spill southwards into eastern North America more readily. Negative NAO winters tend to bring cold winters to Europe, and the prevailing storm track moves south towards the Mediterranean Sea. This brings increased storm activity and rainfall to southern Europe and North Africa.

The winter of 2009 - 2010 has seen a very strong negative NAO, causing much of our cold weather over Eastern North America and Europe. The NAO index for the month of December 2009 was -1.93, which is the third lowest NAO index since 1950 for a winter month (December, January, or February). The only winter months with a lower NAO index were February 1978 (-2.20) and January 1963 (-2.12). January 1963 was one of the coldest months on record in the UK and the Eastern U.S.. February 1978 was the coldest February on record for five U.S. states, and featured the historic blizzards in both the U.S. and UK. The NAO so far for January 2010 has continued to stay strongly negative, ranging between -1.5 and -2.1. However, the blocking ridge over Greenland is forecast to weaken next week, allowing the sharp kink in the jet stream to straighten out. This will increase the NAO index to more typical values, allowing a return of more ordinary winter weather to the U.S. and Europe.

Jeff Masters

From The Porch 1 (suzi46)
from our porch view of sunrise this morning..totally different from the 'splendiferous' shots 1-8 taken from the top of our field overlooking the mountains
From The Porch 1
First snow (Rowdyblue)
of winter in South Mississippi.
First snow
Wind blown snow (bikesnapper)
Like sand dunes or Antelope Canyon
Wind blown snow

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Quoting IKE:
I don't see any in Montgomery,AL. Greenwood,MS. and Tupelo,MS. got some, but the Jackson,MS. office had part of Mississippi under a winter storm warning for awhile, then backed off.



Where is your location?

EDIT>>>I see it...Greensboro...must be NC.


Yes, North Carolina.
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978. IKE
Quoting nrtiwlnvragn:


I looked at Weather Roundup from WFO Tallahassee, clicked through previous.


Thanks for the info. Maybe we had a flake here and I snored through it.

As far as accumulation...most forecasters were way off. Tallahassee office did a great job on this for precip.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
977. IKE
I don't see any in Montgomery,AL. Greenwood,MS. and Tupelo,MS. got some, but the Jackson,MS. office had part of Mississippi under a winter storm warning for awhile, then backed off.

Quoting natrwalkn:


Well I can see justifying making a holiday out of enough snow to play in, but REALLY!! There's NOTHING out there this morning!!


Where is your location?

EDIT>>>I see it...Greensboro...must be NC.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting BahaHurican:
LOL yeah, can identify with that.... remember whenever there was more than 2 inches of snow, school would shut down....


Well I can see justifying making a holiday out of enough snow to play in, but REALLY!! There's NOTHING out there this morning!!
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Quoting IKE:


Thanks.

I saw a couple of "unknown precip" for an hourly report on a couple of sights....

Looking at Crestview...Milton...Pensacola...Mobile...the rain mostly moved out before changing to frozen.

Mobile,AL


Pensacola,FL


Crestview,FL


I looked at Weather Roundup from WFO Tallahassee, clicked through previous.
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Local mets are trying to play this forecast bust off!! The forecast was for moisture to be the limiting factor prohibiting accumulations, NOT the temperature being too warm and precip turning to RAIN!! It was supposed to all be snow. Had the rain we had all been snow, the ground would be white right now. FACE IT mets, you busted this forecast and you should own up to it rather than try to play it off!!
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No snow in Pensacola. Closest we got here was 38 and rain.
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Quoting natrwalkn:
We had a VERY brief period of snow in Greensboro last night before all precip changed to rain. The mets BUSTED on that forecast. However, local schools and governments are running on 2 hour delays anyway!! HA! Just the threat of snow in the south disrupts life.
LOL yeah, can identify with that.... remember whenever there was more than 2 inches of snow, school would shut down....
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971. IKE
Quoting nrtiwlnvragn:


3:00 AM
PANAMA CITY LGT SNOW 38 35 89 N13 30.10R FOG WCI 30


Thanks.

I saw a couple of "unknown precip" for an hourly report on a couple of sights....

Looking at Crestview...Milton...Pensacola...Mobile...the rain mostly moved out before changing to frozen.

Mobile,AL


Pensacola,FL


Crestview,FL
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Another website shows the 41 listed for Nassau, but lists 37 as the lowest record for Freeport, which is north of here.
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We had a VERY brief period of snow in Greensboro last night before all precip changed to rain. The mets BUSTED on that forecast. However, local schools and governments are running on 2 hour delays anyway!! HA! Just the threat of snow in the south disrupts life.
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And a story from this morning's Nassau Guardian:
Cold weather expected for a few days

By JIMENITA SWAIN ~ Guardian Senior Reporter ~ jimenita@nasguard.com:

The next few days are expected to be cold, though not with record breaking temperatures, said chief meteorologist Arnold King.

"The cold spell is going to last for a bit," he told The Nassau Guardian yesterday.

"It's going to be cold for the next few days right through the weekend. We have a surge of cold air moving through The Bahamas."

Another cold front is expected on Friday, which would mean cooler temperatures into the weekend, he said.

"We had a high yesterday (Monday) of 68 degrees and a low last night of 62. The temperatures are going to remain the same," said King.

During the day he said temperatures are going to remain between the upper 60s to low 70s and at night the upper 50s to low 60s.

"The main daily average is like 63 degrees and we are experiencing temperatures just below the 63 degree mark," he said.

King said the temperature is a little bit below average.

On Monday he said the temperature in Freeport, Grand Bahama was pegged at 59 degrees Fahrenheit.

"The high temperature should be in the low 60s today (Tuesday)," he added.

At night temperatures in Grand Bahama, Abaco and Bimini could dip to the low 50s, said King.

"We don't have record breaking temperatures for this time of the year," he noted.

He pointed out that the coldest temperature on record was recorded on January 20, 1981 when the temperature was 41.4 degrees.

"We won't see those kinds of temperatures," he said.

"I think it's bundle up weather to stay inside," said resident Vanessa Davis. "I like the weather."

Nail technician Patera Simmons said, "Everybody wants to stay indoors. I want to be inside. I don't want to go anywhere, but I'm enjoying [the cold weather]. We haven't had cold weather like this in a while."

The cold weather is a stark difference from temperatures last month as December was the hottest month on record.

Last month the average was between 83 to 85 degrees Fahrenheit, the highest average ever recorded for that month.

In addition, he said the highest temperature ever recorded in December was 86.9 degrees Fahrenheit.

"But this year (2009) we have broken that. We've gone up to 88 degrees on a few days," he added.

Wednesday January 06, 2010
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From The Bahamas' Met. Dept.'s website:

Having a tropical maritime wet and dry type climate with winter incursions of modified polar air, generally The Bahamas experiences neither frost, snow, sleet, hail nor extremes of temperatures. A unique exception to that occurred on January 19th, 1977, when parts of the northern Bahamas experienced a brief flurry of light snow. Climatological data (following) covers the 30-year period between 1971 & 2000. The lowest recorded temperature was 41.4°F on January 20th, 1981.
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Quoting IKE:
Well...I don't see any snow on the ground....crow me...

Did anybody get any snow? LOL.

Oh....they give mulligans in golf. Can I get one to start the New Year over? This first 7 days has been :(


3:00 AM
PANAMA CITY LGT SNOW 38 35 89 N13 30.10R FOG WCI 30
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WRF Radar
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Current Conditions


Bismarck, North Dakota (Airport)
Updated: 5:52 AM CST on January 08, 2010
-31 °F
Clear
Windchill: -31 °F
Wind: Calm
Pressure: 30.78 in (Rising)
Visibility: 8.0 miles
UV: 0 out of 16
Clouds: Clear -
(Above Ground Level)
Elevation: 1660 ft


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963. unf97
Good morning!

Hey Ike, there were snow flurries reported at the weather obs sites at Mary Esther, and Destin earlier this morning at midnight CST.

There were a few ice pellets reported at the WFO in Pensacola.
Member Since: September 25, 2007 Posts: 0 Comments: 1193
962. IKE
Dew points in the teens....down to zero on northern Arkansas....air is too dry.

Looking at the 6Z NAM and GFS...cold air is too far north for peninsula Florida to get much frozen precip.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
961. Sh0cK
Current Conditions


Dallas/Ft Worth, Texas (Airport)
Updated: 26 min 7 sec ago

Temp: 17 °F
Mostly Cloudy
Windchill: 1 °F
Humidity: 54%
Dew Point: 3 °F
Wind: 20 mph from the NNW
Pressure: 30.61 in (Steady)

Gonna be a lot of whining going on in North Texas this morning!
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Concession, Belle Chasse, Louisiana (PWS)
Updated: 2 sec ago
Clear
29.0 °F
Clear
Windchill: 24 °F

I guess they changed their minds :)
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WOW!!!

49 degrees at 7:00 a.m.!!!

It's almost 5 degrees colder now than it was at 5 a.m.!!!

Brrrr!!!!!
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I checked radar too. Cant be much to it so far.
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956. IKE
Any snow in Pensacola?
Member Since: June 9, 2005 Posts: 23 Comments: 37858
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954. IKE
Quoting nishinigami:
Concession, Belle Chasse, Louisiana (PWS)
Updated: 3 sec ago
Light Snow
29.0 °F
Light Snow
Windchill: 18 °F
Humidity: 66%
Dew Point: 19 °F
Wind: 8.0 mph from the NW
Wind Gust: 11.0 mph
Pressure: 30.25 in (Rising)
Visibility: 10.0 miles
Elevation: 3 ft

I keep looking for the light snow, but I don't see any.


I don't see any on radar. Shows clear throughout the state...

Member Since: June 9, 2005 Posts: 23 Comments: 37858
00z Global Ens. MOdel Run....

12hrs out




36hrs out



The Cold Front must have stalled some.....



The NAM and RUC both dry up the moisture moving thru Texas.......NOT SURE THAT WILL COMPLETELY HAPPEN......we shall see.




I have 43deg in Tampa at 7am with a dew point of 39!
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Concession, Belle Chasse, Louisiana (PWS)
Updated: 3 sec ago
Light Snow
29.0 °F
Light Snow
Windchill: 18 °F
Humidity: 66%
Dew Point: 19 °F
Wind: 8.0 mph from the NW
Wind Gust: 11.0 mph
Pressure: 30.25 in (Rising)
Visibility: 10.0 miles
Elevation: 3 ft

I keep looking for the light snow, but I don't see any.
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951. IKE
As far as frozen precip further downstate, I don't see much to it. Get a magnifying glass and maybe you can see a flake.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Everything appears to be starving for mositure.
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Current Conditions

Uptown, New Orleans, Louisiana (PWS)
Updated: 2 min 2 sec ago
Light Snow
29.2 °F
Light Snow
Windchill: 21 °F
Humidity: 56%
Dew Point: 17 °F
Wind: 8.0 mph from the North
Wind Gust: 16.8 mph
Pressure: 30.30 in (Rising)
Visibility: 10.0 miles
Elevation: 20 ft
Member Since: July 3, 2005 Posts: 426 Comments: 128764
44º here in coastal Jax. Seems almost pleasant.

A bit of a drizzle today, then temps plummeting again after sundown. No snow for NE Florida, but a little further south and west might see some other forms of precip than just rain.

Please let this be the last of our winter foolishness.
Member Since: August 13, 2005 Posts: 168 Comments: 26076
947. IKE
Well...I don't see any snow on the ground....crow me...

Did anybody get any snow? LOL.

Oh....they give mulligans in golf. Can I get one to start the New Year over? This first 7 days has been :(
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Starting to cool down up here. Iron Mountain, Michigan (Airport)
Updated: 4:54 AM CST on January 08, 2010
15 °F
Light Snow
Windchill: -1 °F
Humidity: 70%
Dew Point: 7 °F
Wind: 16 mph from the NNW
Wind Gust: 26 mph
Pressure: 30.26 in (Rising)
Visibility: 6.0 miles
UV: 0 out of 16
Clouds: Overcast 2900 ft
(Above Ground Level)
Elevation: 1181 ft

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944. HadesGodWyvern (Mod)
Mauritius Meteorological Services
Tropical Cyclone Advisory Number SIXTEEN
CYCLONE TROPICAL INTENSE EDZANI (08-20092010)
10:00 AM Réunion January 8 2010
======================================

At 6:00 AM UTC, Intense Tropical Cyclone Edzani (915 hPa) located at 15.6S 77.7E has 10 minute sustained winds of 110 knots with gusts of 155 knots. The cyclone was reported as moving west-southwest at 6 knots.

Dvorak Intensity: T6.5/6.5/D2.0/24 HRS

Hurricane Force Winds
======================
40 NM from the center

Storm Force Winds
==============
60 NM from the center

Gale-Force Winds
=================
100 NM from the center

Near Gale-force Winds
======================
160 NM from the center extending up to 200 NM in the southern semi circle

Forecast and Intensity
=====================
12 HRS: 16.0S 76.3E - 110 knots (CYCLONE Tropical Intense)
24 HRS: 16.9S 74.7E - 110 knots (CYCLONE Tropical Intense)
48 HRS: 18.8S 71.5E - 100 knots (CYCLONE Tropical Intense)
72 HRS: 20.9S 69.3E - 80 knots (CYCLONE Tropical)

Additional Information
=========================
Environmental conditions are still very favorable up to 36 hrs (particularly with a persisting equatorward upper outflow channel and a polar one building between 24-36 hours and sea surface temperatures are expected to keep on staying more than 27C sea surface temperatures until 48 hrs (west-southwest movement) and beyond sea surface temperature should lower more rapidly. EDZANI is expected therefore to stay steady or weaken slowly until 36-48 hrs, beyond its intensity should weaken more rapidly. The steering flow is a deep ridge in the southeast of the system. At the end of the range forecast, atrough south of the system should steer it more southern ECMWF ensemble prediction system gives 2 equiprobably scenario, one with recurve movement towards the trough, the other one without this forecast is a consensus of the available determinist Numerical Weather Prediction models which are in rather good agreement on the track and the speed of the system.
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Bedtime for Bonzo. Nite all.
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Quoting FLPandhandleJG:

I live in Bluewater Bay behind the winn dixie.. it was couple of days ago.. that was crazy and scary if a car was coming..

Hmm, interesting...I'm in the Woodlands. What caused the ice I wonder? Some douchebag who forgot to turn off their sprinkler system (which makes no sense this time of year anyway since the grass isn't growing)?
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Quoting Bordonaro:
To all my blogging buddies, good night, stay safe. I am praying that Dr Jesus Christ will deliver snow in modest amounts to the Gulf Coast region. Peace be with all of you.

Be back around 9-11AM CST :0)!!


goodnight bob.. im heading out too.. hopefully we get unexpected gulf coast storm.. that would b awesome.. be safe everyone..
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To all my blogging buddies, good night, stay safe. I am praying that Dr Jesus Christ will deliver snow in modest amounts to the Gulf Coast region. Peace be with all of you.

Be back around 9-11AM CST :0)!!
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Quoting quakeman55:

Ouch...yeah, you got lucky! Where was that at?

I live in Bluewater Bay behind the winn dixie.. it was couple of days ago.. that was crazy and scary if a car was coming..
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Quoting JGreco:


Weather channel radar is showing snow headed toward your direction:)

Yep, that's when I ducked back outside for a little while longer...I saw the same "tiny snowflakes" in the floodlight I saw earlier...just not sure if they were in fact little snowflakes or tiny raindrops. They seemed to behave like little snowflakes though. We just need more moisture to come in!
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Quoting FLPandhandleJG:

ya the other day when i was heading to work.. I was heading toward my stop sign b4 i get out of my neigborhood, right then i hit sum ice that i didnt see.. i start sliding all the way past the stop sign into the highway.. good thing there wasnt even any cars coming or i would b toast.. but i was like shiznit.. that gave me a scare for sure..

Ouch...yeah, you got lucky! Where was that at?
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Quoting xcool:
I THINK N.O LA GO TO SNOW


and maybe heads toward the fl panhandle.. that would be nice ;)
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OOPS, Snow in W TX, moving East

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dang.. no more snow chances for awhile for me.. all i saw was little sleet if that.. maybe we get a surprise tomorrow and get more moisture with this artic blast..
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929. xcool
lot of Moisture over New Mexico
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.