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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Where's the mechanism to give us a return flow?
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1077. Patrap






Member Since: July 3, 2005 Posts: 426 Comments: 128736
Quoting CycloneOz:


...that's lasagna shoved up my boss's rear end...that's lasagna scrunched up in a paper towel...that's lasagna that wanted to be rigatoni...


LOL...an intelligent imbecile nyuck nyuck
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Gettin' whooped in chess onlne at the moment!
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Quoting CycloneOz:


Too bad they're lame! :)

Doug, whatcha doin?!?!?!

I'm getting a hand rub!


Oz, can you say that in here?
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I'm getting a hand rub!

Is that legal?
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Quoting TampaFLUSA:
Are the temps still going to be colder than previous here? I have plants lol...
The temps won't be that much colder than they were with the last front, but mid 20s north of the Bay are expected.
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Quoting CycloneOz:


LOL, I always see lasagna.


You too? Drives the docs nuts...thats lasagna; that one is lasagna thrown against the wall; that's lasagna dropped on the floor...
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Quoting PensacolaDoug:
I remember when you took those!


It took me two hours to find them. I also located the Ark of the Covenant that I had misplaced during my search yesterday!
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Are the temps still going to be colder than previous here? I have plants lol...
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I remember when you took those!
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Quoting Floodman:


A lot of screaming going on at the Casa last night...most of it after Sabin, 1:48 left on the clock, decided to run up the score. A class coach would have taken a knee and let the game end. Sabin proves again what he showed when he left LSU: he is a no-class individual

Okay, enough on that score

Give 'em hell, Harry...
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Quoting AwakeInMaryland:


LOL. Reminds me... are you and Mrs. Flood okay? Salty tears in your beers? After "the" game last night...looked pretty good there for awhile (I know nothing about football, so I'm easily impressed).


A lot of screaming going on at the Casa last night...most of it after Sabin, 1:48 left on the clock, decided to run up the score. A class coach would have taken a knee and let the game end. Sabin proves again what he showed when he left LSU: he is a no-class individual

Okay, enough on that score
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Quoting TampaTom:
...BTW - in those ink-blot tests, I saw three elephants, a battleship and Carmen Miranda....


LOL, I always see lasagna.
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Quoting TampaTom:


Time for snipe hunting! I'll bring the s'mores makin's. :-)

BTW - in those ink-blot tests, I saw three elephants, a battleship and Carmen Miranda....

Oh waiter...I'll have what he's having, please!
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Quoting CycloneOz:
Hi and good morning everyone!

Back in January 1983, I took my first time-lapsed pictures at the Pensacola NAS National Cemetary.

YOU'LL FREAK WHEN YOU SEE THEM!

They're out there now, on the internet. A special EXCLUSIVE from a fellow severe weather enthusiast!

Enjoy! :)


I don't see anything in those photos, what a load. IMO
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1060. Patrap
I saw Joan of Arc Weds Night here in Jackson Square,,it was her Birthday too,..

She looked really Beautiful for 598.

Just click on my handle here to see the pics.
Member Since: July 3, 2005 Posts: 426 Comments: 128736
Quoting CycloneOz:


Ack...I messed up on the photo descriptions. I'll have to fix that.

Pic 1 - Description correct

Pic 2 - Face still in tree, but the "energy beam" is bigger and brighter.

Pic 3 - A whole bunch of "energy beams" gathering?

In 1984, I gave the prints and negatives to my B&W photography instructor at PJC.

He was at a loss to explain them.

...and the mystery of them remains to this day.

I'm in the mood for a campfire now! :)


Time for snipe hunting! I'll bring the s'mores makin's. :-)

BTW - in those ink-blot tests, I saw three elephants, a battleship and Carmen Miranda....
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1058. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128736
Quoting AwakeInMaryland:
Chirp...Chirp...crickets...

Everyone must be looking at Oz's linked pics.
Spooky for sure!


Ack...I messed up on the photo descriptions. I'll have to fix that.

Pic 1 - Description correct

Pic 2 - Face still in tree, but the "energy beam" is bigger and brighter.

Pic 3 - A whole bunch of "energy beams" gathering?

In 1984, I gave the prints and negatives to my B&W photography instructor at PJC.

He was at a loss to explain them.

...and the mystery of them remains to this day.

I'm in the mood for a campfire now! :)
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Quoting Floodman:


Yeah, Mizzou should have feared The Goat...


LOL. Reminds me... are you and Mrs. Flood okay? Salty tears in your beers? After "the" game last night...looked pretty good there for awhile (I know nothing about football, so I'm easily impressed).
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Quoting AwakeInMaryland:
USA777 -- HAPPY BIRTHDAY!!!
Alrighty now, if there's a human being out there who won't "get" this -- USA777 is in the great little city of Annapolis, MD. He's a Capricorn...the sign of the GOAT...and the home of the also-great U.S. Naval Academy...
Therefore, let it be known throughout the land:



Yeah, Mizzou should have feared The Goat...
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Chirp...Chirp...crickets...

Everyone must be looking at Oz's linked pics.
Spooky for sure!
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Quoting usa777:


Unbelieveable!!! Good morning Awake. It looks like I got about an inch of snow last night. How about you?

HeeHee...I'm fine as wine! Re the sneaux, pls. see my earlier post #122!! How YOU doin'?
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Quoting atmoaggie:

You guys are expecting lows in the middle teens in coastal counties?!? Not seeing that...where?


no
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Hi and good morning everyone!

Back in January 1983, I took my first time-lapsed pictures at the Pensacola NAS National Cemetary.

YOU'LL FREAK WHEN YOU SEE THEM!

They're out there now, on the internet. A special EXCLUSIVE from a fellow severe weather enthusiast!

Enjoy! :)
Member Since: Posts: Comments:
Wundermap radar for Big Bend coastal area seems to show a mix-but weather stations not reporting anything of note.
http://www.wunderground.com/wundermap/?lat=30.40044&lon=-84.32329&zoom=9&type=ter&units=english&rad =1&rad.num=13&rad.spd=25&rad.opa=70&rad.stm=0&rad.type=N0R&rad.smo=1&rad.mrg=0&wxsn=0&svr=0&cams=0&s at=0&riv=0&mm=0&hur=0&fire=0&tor=0&ndfd=0&pix=0&dir=0
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USA777 -- HAPPY BIRTHDAY!!!
Alrighty now, if there's a human being out there who won't "get" this -- USA777 is in the great little city of Annapolis, MD. He's a Capricorn...the sign of the GOAT...and the home of the also-great U.S. Naval Academy...
Therefore, let it be known throughout the land:

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Quoting RitaEvac:


Or the cold went more south down the plains instead of SE

You guys are expecting lows in the middle teens in coastal counties?!? Not seeing that...where?
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Quoting atmoaggie:

Ehh, maybe it was just NWS NOLA calling for temps too low at first and adjusting upwards...


Or the cold went more south down the plains instead of SE
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Good Morning Everyone!
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Quoting AwakeInMaryland:
Another outrage...I would have volunteered to pick up a carload for Portlight. Still could...

H&M and Wal-Mart destroy and trash unsold goods
by Joanna Douglas, Shine Staff

This week the New York Times reported a disheartening story about two of the largest retail chains. You see, instead of taking unsold items to sample sales or donating them to people in need, H&M and Wal-Mart have been throwing them out in giant trash bags. And in the case that someone may stumble on these bags and try to keep or re-sell the items, these companies have gone ahead and slashed up garments, cut off the sleeves of coats, and sliced holes in shoes so they are unwearable.

This unsettling discovery was made by graduate student Cynthia Magnus outside the back entrance of H&M on 35th street in New York City. Just a few doors down, she also found hundreds of Wal-Mart tagged items with holes made in them that were dumped by a contractor.
(Story continues...)


Unbelievable...
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Lawrenceville-Vincennes Intl Airport
Lat: 38.76 Lon: -87.6 Elev: 430
Last Update on Jan 8, 8:53 am CST

Light Snow

13 °F
(-11 °C)
Humidity: 74 %
Wind Speed: W 14 MPH
Barometer: 30.28" (1026.1 mb)
Dewpoint: 6 °F (-14 °C)
Wind Chill: -2 °F (-19 °C)
Visibility: 2.50 mi.
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Quoting jeffs713:

Our forecast actually came in a couple of degrees too high. The forecasted low this morning was 27, we came in at 25. They did bump the daytime "high" up to 34 (for IAH, its still forecasted for 32 here) from 31.

They kept the low tonight the same for IAH at 21, and for my area at 20. (Conroe, just north of here, is forecast for 19)

Ehh, maybe it was just NWS NOLA calling for temps too low at first and adjusting upwards...
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Quoting atmoaggie:

And it doesn't seem to be quite as strong as expected...so far.
Over the last 36 hours, or so, our forecast temps have trended upward. We were forecast to bottom out at 14 F tonight, now expecting 21 F.

Our forecast actually came in a couple of degrees too high. The forecasted low this morning was 27, we came in at 25. They did bump the daytime "high" up to 34 (for IAH, its still forecasted for 32 here) from 31.

They kept the low tonight the same for IAH at 21, and for my area at 20. (Conroe, just north of here, is forecast for 19)
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1041. IKE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
957 AM EST FRI JAN 8 2010

.UPDATE...VERY COLD AND VERY DRY AIR BEHIND THE COLD FRONT WILL
CONTINUE TO MAKE IT WAY SOUTH TOWARDS THEN CENTRAL PENINSULA.
ALREADY MAKE A COUPLE CHANGES TO THIS VERY TRICKY FORECAST
PACKAGE BY UPGRADING TOMORROW`S FREEZE WATCH TO A WARNING FOR
CITRUS...HERNANDO AND SUMTER CO WHILE UPGRADING THE WATCH TO A
HARD FREEZE WARNING FOR LEVY CO. LOOKING AT THE 6Z MODEL
GUIDANCE...DECIDED TO DECREASE POPS FOR OUR NORTHERN HALF OF THE
CWA AND REMOVED ANY PRECIP FROM HILLSBOROUGH NORTHWARD AT 8Z. A
COUPLE CONCERNS FOR THE AFTERNOON FORECAST EXIST IN THAT OVC
CONDITIONS WILL REMAIN BEHIND THE FRONT AND PRECIP WHICH WILL
LIMIT RADIATIONAL COOLING SO THE FREEZING CONDITIONS WILL HINGE
ON ADVECTION. THE NEXT CONCERN WILL BE ANY LINGER PRECIP BEHIND
THE FRONT EARLY TOMORROW MORNING FOR AREAS NORTH OF PASCO. STILL
EXPECTING ALL PRECIP TO BE WELL SOUTH OF THE FREEZING LINE BUT
WILL WAIT FOR THE 12Z GUIDANCE TO MAKE THE CALL REGARDING POPS AND
WEATHER NORTH OF HILLSBOROUGH.

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Upper level L nearby, to boot.



Wow. A possible stacked-at-all-levels low over land with a surface pressure below 1000 mb. That has the chance to be a rough ride...
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Wow. Going to have to pay attention next weekend if this holds up.

We'll have a surface low coinciding with the mid-level trough. Yes, that does say L 999 (mb).

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Quoting atmoaggie:

And it doesn't seem to be quite as strong as expected...so far.
Over the last 36 hours, or so, our forecast temps have trended upward. We were forecast to bottom out at 14 F tonight, now expecting 21 F.


mine have held steady for around 2 days.
Member Since: September 6, 2009 Posts: 2 Comments: 3763
MODEL SOUNDINGS SHOW THE TEMP PROFILE GOING ISOTHERMAL (BTWN 0C AND
1C) WITH SOME POTENTIAL FOR ADDITIONAL (EVAPORATIVE) COOLING AS
PRECIP FALLING OUT OF SATURATED LYR FALLS INTO THE DEEPENING COLD
POST-FRONTAL AIR MASS. WITH THIS MODELED SCENARIO...SLEET OR GRAUPEL
WOULD BE MORE LIKELY THAN WET FLAKES GIVEN THE TEMP PROFILE
. THERE
WILL BE A LIMITED TO A 4-6 HR WINDOW ACROSS THE NRN HALF CWA WHERE
THE POST FRONTAL PRECIP AND THE COLD AIR COLLIDE.

THOUGH THE 00Z MODEL SOUNDINGS SHOW THE TIMING OF THE COLD AIR
ADVECTION A LITTLE SLOWER THAN THE PREVIOUS RUN...THEREBY KEEPING
TEMPS A DEGREE OR TWO WARMER...THE POSSIBILITY FOR EVAPORATION
FURTHER COOLING THE LAYER CANNOT BE IGNORED AND HAVE LEFT THE
MENTIONS OF LIGHT SLEET OR SNOW FLURRIES MIXING IN WITH THE RAIN
BETWEEN 09Z AND 15Z FROM ABOUT CAPE CANAVERAL TO KISSIMMEE
NORTHWARDS. SOUTHERN BREVARD/OSCEOLA WILL BE TRICKIER AS THE MODELS
KEEP THEM A FEW DEGREES WARMER AND A LITTLE MORE SATURATED.

LIGHT FROZEN PRECIP LAST OCCURRED IN ECFL IN JANUARY 2003, AND ALSO
OCCURRED IN NOVEMBER 2006 AND JANUARY 2008.
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1036. 47n91w
Quoting divdog:
i live in niceville, no snow last night


Valparaiso / Eglin Air Force Base reported light rain & snow at 00:55 early this morning: 3-Day History of KVPS
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1035. RTLSNK
24.4*F in Macon Georgia at 0900 hrs this morning. Temps were still 37.6*F at midnight last night. Rain came through between 0030 and 0300 hrs. Temp didn't drop below 32 until 0500 hrs this morning. No Snow for Macon. :)

Sorry Orca, you missed me. :)
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The front slowed down and now it shows the coldest temps to occur over night on Sunday into Monday.
Member Since: September 6, 2009 Posts: 2 Comments: 3763
Quoting TampaSpin:
Ya the cold air just has not arrived to the south as fast.....as they thought.

And it doesn't seem to be quite as strong as expected...so far.
Over the last 36 hours, or so, our forecast temps have trended upward. We were forecast to bottom out at 14 F tonight, now expecting 21 F.
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Well everyone I'm gonna attempt to get home today. Hopefully I can get around this nasty ice and get out onto main roads. (2nd attempt)
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Quoting jeffs713:
So when I was driving to work this morning (6:45am) in The Woodlands, TX, it was a toasty 24.9F. No ice, or even frost, just very nice and chilly. (this air mass is SUPER dry)

No ice on roads on my drive, either. One would have to look in a ditch or a poorly drained parking lot to find some.
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1030. usa777
Quoting AwakeInMaryland:
Another outrage...I would have volunteered to pick up a carload for Portlight. Still could...

H&M and Wal-Mart destroy and trash unsold goods
by Joanna Douglas, Shine Staff

This week the New York Times reported a disheartening story about two of the largest retail chains. You see, instead of taking unsold items to sample sales or donating them to people in need, H&M and Wal-Mart have been throwing them out in giant trash bags. And in the case that someone may stumble on these bags and try to keep or re-sell the items, these companies have gone ahead and slashed up garments, cut off the sleeves of coats, and sliced holes in shoes so they are unwearable.

This unsettling discovery was made by graduate student Cynthia Magnus outside the back entrance of H&M on 35th street in New York City. Just a few doors down, she also found hundreds of Wal-Mart tagged items with holes made in them that were dumped by a contractor.
(Story continues...)


Unbelieveable!!! Good morning Awake. It looks like I got about an inch of snow last night. How about you?
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Quoting southfla:
Another problem in South Florida is the lack of heat in many office buildings and schools. My office building has no heating capability at all. Yesterday the office was a balmy 64 degrees. A friend who is a teacher in S.Fla told me last night that the classroom she is in is a steady 58 degrees. Brrr. After this weekend, the office won't warm up until maybe Thursday next week.


My high school was one of the first to get let git school wide heating system. Man that thing could crank up the heat.
Member Since: September 6, 2009 Posts: 2 Comments: 3763

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.