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Juliancolton

Intense NATL low

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I don't believe this has a thread yet (if so, apologies), but a North Atlantic low southeast of Greenland has been consistently predicted by models to bottom out under 930mb. I believe 928mb would be among the strongest extratropical lows in the Atlantic ever recorded.

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I don't believe this has a thread yet (if so, apologies), but a North Atlantic low southeast of Greenland has been consistently predicted by models to bottom out under 930mb. I believe 928mb would be among the strongest extratropical lows in the Atlantic ever recorded.

was just about to post this! interesting stuff :arrowhead:

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We had this discussion before about how low do the deepest NATL lows get- I seem to remember 916 or so is the lowest, but my memory may be faulty....

apparently a NATL low got down to 914 near iceland in Jan 1993. It currently holds the record for lowest extratropical pressure

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Pardon my ignorance, but is there anything in particular that causes lows to deepen that much at those latitudes? Is it just because they continually to strengthen after they are formed further south in the Atlantic? I guess the point of origin for these is typically the CONUS? I guess I'm mainly curious about what was the deepest low to impact the eastern seaboard, specifically during winter and whether or not a Sub 930 Low pressure could ever form this far south.

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Pardon my ignorance, but is there anything in particular that causes lows to deepen that much at those latitudes? Is it just because they continually to strengthen after they are formed further south in the Atlantic? I guess the point of origin for these is typically the CONUS? I guess I'm mainly curious about what was the deepest low to impact the eastern seaboard, specifically during winter and whether or not a Sub 930 Low pressure could ever form this far south.

I think some of it has to do with exposure to the Gulf Stream which runs up the U.S. East Coast and then cuts towards Iceland and Scandinavia.

One of the deepest lows to impact the Eastern Seaboard was the March 1, 1914 Nor'easter. A pressure of 952mb was observed at Bridgehampton, NY on Long Island. The powerful storm dealt over 20" of snow to much of New Jersey and New York with winds over 60mph in some places. I have never heard of a 930mb low at this latitude, I think it just takes too long to develop.

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I don't believe this has a thread yet (if so, apologies), but a North Atlantic low southeast of Greenland has been consistently predicted by models to bottom out under 930mb. I believe 928mb would be among the strongest extratropical lows in the Atlantic ever recorded.

Yea I noticed this earlier, very interesting. There are costal cities on that side of greenland so I can only imagine what they are going through right now.

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I think some of it has to do with exposure to the Gulf Stream which runs up the U.S. East Coast and then cuts towards Iceland and Scandinavia.

One of the deepest lows to impact the Eastern Seaboard was the March 1, 1914 Nor'easter. A pressure of 952mb was observed at Bridgehampton, NY on Long Island. The powerful storm dealt over 20" of snow to much of New Jersey and New York with winds over 60mph in some places. I have never heard of a 930mb low at this latitude, I think it just takes too long to develop.

I was thinking the Gulf Stream too, but actually, lows in the GOA have gotten down to the 920's range and <930 is not at all uncommon in the Antarctic regions. Really it has mostly to do with baroclinicity, which increases as temperature decreases. That's why an extratropical 920mb low will not happen down in NYC, why winter extratropical storms are more potent than summer extratropical storms, and why fronts lose steam as they plunge southward. The physical reason for why this is, I'll leave for a met to answer,

BTW, a low bottomed out at 926mb southeast of Greenland in Dec 2006, so while rare, it does happen occasionally.

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I was thinking the Gulf Stream too, but actually, lows in the GOA have gotten down to the 920's range and <930 is very common in the Antarctic regions. Really it has mostly to do with baroclinicity, which increases as temperature decreases. That's why an extratropical 920mb low will not happen down in NYC, why winter extratropical storms are more potent than summer extratropical storms, and why fronts lose steam as they plunge southward. The physical reason for why this is, I'll leave for a met to answer,

BTW, a low bottomed out at 926mb southeast of Greenland in Dec 2006, so while rare, it does happen occasionally.

Yeah, the Southern Ocean has some pretty intense systems. I lived in Southern Chile (city of Valdivia) for a semester during the austral winter, and we'd have very powerful storms with drenching WAA rains, hail, winds gusting over 50mph, dense fog...and then the cold front would move through and drop temperatures into the 20s with drier air from the South Pacific High. It was literally rinse and repeat as the town averages nearly 100" rainfall per year, with barely any snow. The Andes get pummeled with snow at that latitude from the frequent 940mb lows in the Southern Ocean.

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Actually rain. See link.

Tasiilaq is part of a promontory extending into the ocean, so it's not representative of the climate of areas further inland that would definitely be seeing snow. It looks as if 850mb temperatures at 6z support snow for all of Greenland, but the surface may be a bit mild for areas like Tasiilaq due to powerful northeast winds adding funneling in the maritime air...

850s:

2m temps:

There must be incredible contrasts in Greenland between relatively mild and often rainy coastal towns, versus the harsh interior where nary a raindrop falls in winter, at least normally.

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1030Z forecast is 928 mb

HURRICANE FORCE WIND WARNING

.LOW 46N48W 972 MB MOVING NE 35 KT AND RAPIDLY INTENSIFYING.

WITHIN 360 NM SE...540 NM S...AND 180 NM NW QUADRANTS WINDS 40

TO 55 KT. SEAS 17 TO 29 FT...EXCEPT IN NW QUADRANT 12 TO 20 FT.

ELSEWHERE FROM 31N TO 49N BETWEEN 39W AND 65W WINDS 25 TO 40 KT.

SEAS 10 TO 20 FT.

.12 HOUR FORECAST LOW 52N36W 937 MB. WITHIN 300 NM SW AND 180 NM

W QUADRANTS WINDS 55 TO 85 KT. SEAS 24 TO 44 FT.

.24 HOUR FORECAST LOW E OF AREA NEAR 56N32W 928 MB. OVER

FORECAST WATERS WITHIN 300 NM W AND SW QUADRANTS WINDS 60 TO 80

KT. SEAS 24 TO 44 FT. ELSEWHERE WITHIN 600 NM S AND 360 NM W AND

NW QUADRANTS WINDS 40 TO 60 KT. SEAS 20 TO 35 FT. ALSO WITHIN

540 NM NW QUADRANT AND FROM 42N TO 57N E OF 57W WINDS 25 TO 40

KT. SEAS 12 TO 30 FT...HIGHEST NEAR 48N38W.

.48 HOUR FORECAST LOW 61N35W 938 MB. WITHIN 480 NM SW QUADRANT

WINDS 40 TO 60 KT. SEAS 30 TO 50 FT. ELSEWHERE WITHIN 240 NM

NW...420 NM W...AND 660 NM SW QUADRANTS WINDS 25 TO 40 KT. SEAS

18 TO 36 FT.

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For a fuller treatment of that particular case, wikipedia has a good page on it:

http://en.wikipedia.org/wiki/Braer_Storm_of_January_1993

It even discusses how common lows below 930 hPa are in the northern Atlantic.

The record for the North Atlantic was estimated at 914 mb on 1/10/93 but 928 mb is still really impressive to see.

http://www.metoffice...anuary_1993.pdf

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I think some of it has to do with exposure to the Gulf Stream which runs up the U.S. East Coast and then cuts towards Iceland and Scandinavia.

One of the deepest lows to impact the Eastern Seaboard was the March 1, 1914 Nor'easter. A pressure of 952mb was observed at Bridgehampton, NY on Long Island. The powerful storm dealt over 20" of snow to much of New Jersey and New York with winds over 60mph in some places. I have never heard of a 930mb low at this latitude, I think it just takes too long to develop.

Don't forget about the Norfolk and Long Island hurricane of 1821. You could say that the observations aren't reliable(1821..:whistle:) but the wind obs(adjusted for latitude), argue for something below or around 930mb.

The classic 1938 long island express bottomed out around 938mb.

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Is the NA the stormiest place in the world? There is always something intense there.

The Icelandic Low is one of the semi-permanent pressure features in the northern hemisphere. It's complement is the Aleutian Low. Also Bermuda High/Azores High, etc...

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Don't forget about the Norfolk and Long Island hurricane of 1821. You could say that the observations aren't reliable(1821..:whistle:) but the wind obs(adjusted for latitude), argue for something below or around 930mb.

The classic 1938 long island express bottomed out around 938mb.

There is no way that storm was below or around 930 that far north and after trekking over land. Maybe at NC landfall.

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There is no way that storm was below or around 930 that far north and after trekking over land. Maybe at NC landfall.

I are disappoint. Hard to believe a cold-core cyclone could become deeper than a Category 3 hurricane.

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I are disappoint. Hard to believe a cold-core cyclone could become deeper than a Category 3 hurricane.

Category 3 TCs can have pressures as high as the 960 mb range. It's not unusual at all for an extratropical system to achieve deeper pressures than that.

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There are actually TWO amazing cyclones in the N. Atl right now.

The first one is the one further north, analyzed at 937 mb per the 12Z ECMWF (and has supposedly deepened since then). The second, equally interesting cyclone (IMHO) is the one currently undergoing baroclinic transition to the south of the monster low which has DEEPENED BY 34 MB IN 12 HRS (991 to 957 mb)!

ECMWF 00Z Analysis:

post-378-0-37457800-1297454514.gif

ECMWF 12Z Analysis:

post-378-0-50127200-1297454586.gif

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The North Pacific isn't exactly peaceful either. It's as stormy as the NATL however, shipping lanes don't go as far north there. Lowest pressure in a NPAC (actually Bering Sea) ET cyclone is around 922 mb. For that matter, the latitudes south of 40S in the Southern Hemisphere tend to be wild as well during the Austral Winter.

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