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By: Dr. Jeff Masters, 3:24 PM GMT on February 14, 2006

Did the Blizzard of 2006 have hurricane-like characteristics? Yes, it did. To explore this more fully, let's look at the two basic types of large scale (synoptic-scale) storms that meteorologists define:

1) Tropical cyclones (hurricanes), which have a warm core, and derive their energy from the latent heat of condensation. When water vapor condenses into rain, the phase change from gas to liquid liberates some extra heat energy--the latent heat--that was used to evaporate the water in the first place. Since maximum evaporation in the atmosphere occurs over the warmest ocean waters, tropical cyclones thrive in the late summer when ocean temperatures are at their peak.

2) Extratropical cyclones (mid-latitude cyclones), which have a cold core, and derive their energy from the potential energy released when cold air aloft sinks and is replaced by warmer, less dense air. Extratropical cyclones develop where two air masses of sharply different densities (and thus, temperatures) intersect. Extratropical cyclones exist only outside of the tropics (thus are "extra"-tropical), where there is some cold air to be found. The ordinary low pressure systems that bring rain and snow to residents of the mid-latitudes are examples of extratropical cyclones.

In recent years, meteorologists have begun to discover that many extratropical cyclones--including Nor'easters, which are strong wintertime extratropical cyclones that affect the Northeast U.S.--can make a partial transition to a warm-core system once they move out over the warm waters of the Gulf Stream. Like a hurricane, deep convection will appear near the center of the storm, and the hybrid system will begin to draw energy from the latent heat of condensation. These storms can "bomb" and deepen at rates of 10 mb/hour, and reach central pressures normally associated only with major hurricanes.

Figure 1. The Blizzard of 2006, visible satellite image from NOAA for Sunday February 12 2006. Note the eye-like feature south of Rhode Island. The "eye" was near the edge of the Gulf Stream, where water temperatures increased sharply from 6 degrees to 12 degrees C.

According to Louis Uccellini and Mel Shapiro, extratropical cyclone experts with NOAA, these storms may be undergoing a "seclusion" process that creates an semi-isolated tropical system in the midst of an extratropical cyclone. In the seclusion process, a strong extratropical cyclone draws in warm air from the south, and latent heat of condensation from the cyclone's intense precipitation makes this air even warmer. This extra-warm air spirals into the center of the low and wraps around to the west side, where it is pinched off. As result, one has an isolated "warm core" center where deep convection builds and spiral banding can occur. However, unlike a hurricane, there is no eyewall, and no cloud-free eye created by sinking air (subsidence) in the center. The eye-like feature in an extratropical cyclone has upward moving air, and is merely the center where the surface winds spiral into. Spiral bands of convection can develop in the warm air near the center, mimicking the spiral bands of a hurricane. If these convective bands become intense, subsiding air on the flanks of the bands may create subsidence that warms and dries out the surrounding air, creating cloud-free regions near the center that may give it a more eye-like appearance. Another difference with hurricanes is that the upper-level high pressure system (anticyclone) over the extratropical cyclone is displaced to the northeast (downwind) of the center. In a hurricane, the anticyclone is directly over the eye.

The Blizzard of 2006 developed a distinct eye-like feature when it moved offshore over the warm Gulf Stream waters. The storm was undoubtedly tapping the hurricane's source of energy--latent heat of condensation--at the time the photo in Figure 1 was taken, since we can see evidence of spiral banding occurring neat the center of the storm. As seen in Figure 2, the Sea Surface Temperatures increased sharply from 6 to 12 degrees C (43 to 54 degrees F) near where this eye-like feature developed, right along the edge of the Gulf Stream current. There was plenty of water warm water for the storm to tap into for an extra energy source.

However, the storm missed the warmest waters of the Gulf Stream to its south, and did not intensify much compared to other historic blizzards--the storm's central pressure only dropped to about 980 mb, and a pressure of 960 mb is more typical of a classic Nor'easter "bomb". Also, note that the band of heavy snow that extends from Long Island through Connecticut northeastwards is well away from the center of the cyclone. This band is what gave the Blizzard of 2006 its prodigious snow amounts, and the band developed just as the storm moved off the coast--well before the warm ocean waters had time to create a warm-core seclusion in the storm and enhance the storm's snowfall. This band of heavy snow was created by processes unrelated to the formation of a warm core in the cyclone. The band had some similarities to the intense bands of lake-effect snow one finds in the lee of the Great Lakes--drier, fluffier snow than one usually finds in a Nor'easter, and very high snowfall rates of up to four inches per hour. Lake effect snow bands, and the extreme snow band of the Blizzard of 2006, are examples of developments on the "mesoscale"--the scale of a few tens of kilometers--and are not well handled by computer forecast models. These models typically chop the atmosphere into grid cells between 20 km and 40 km square, and thus were not able to resolve features like the extreme snow band of the Blizzard of 2006, which concentrated its heavy snow into a band just 10 or 20 kilometers wide.

Figure 2. Sea Surface Temperatures at the time of the Blizzard of 2006.

From the Sea Surface Temperature plot in Figure 2, we can see that much warmer water lies further south, along the North Carolina coast. The Gulf Stream moves parallel to the coast here. The Blizzard of 2006 missed tracking over this warmer water, since the storm popped off the coast near New Jersey then tracked due east. Thus if a winter storm crossing the U.S. can take a track so that it moves offshore near the Carolinas, then move northeastwards along the axis of the Gulf Steam, it will spend a longer time over much warmer waters than the Blizzard of 2006 did, and have chance to really tap into that latent heat of condensation energy that powers hurricanes. This is what happened to a January 1989 cyclone I flew into as part of a field project the Hurricane Hunters were participating in, called the Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA). This storm "bombed" while we flew through it, the pressure dropping an astounding 60 mb in 24 hours, bottoming out at 938 mb. I'll have the tale of the rough ride through that storm later this week.

Jeff Masters

Winter Weather

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Interesting - thanks, Dr. Masters.
I had noticed that these north Atlantic storms occasionally dip into the warm-core realm, and your interpretation of a small tropical-esque system surrounded by extratropical conditions makes sense!

Looking forward to tomorrow's entry. 8)
It's happened, Merovingian.

Happy VDays people, learn something new everyday from the great Dr. Masters.

Here is a good example of a extra-cyclonic system producing a bomb (correct me if I am wrong Dr. Masters)

Great job Dr. Masters on this one. And a great pic of that storm Colby.

Giants in 06
That 1991 storm was the Great Halloween Storm also known as Perfect Storm. In the 1991 case a full tropical cyclone developed within the center of the then weakening extratropical low as it drifted southward over the Gulf Stream.
Very interesting, thanks Dr.Masters. Blizzicane is a better sounding term than snowcane too.

Blizzicane...I like it...

My brother lives in NYC...they got buried...27 inches of snow...glad I moved to Florida...
Hey TampaSteve
I live in Tampa and had to use my Florida Ice Scraper (credit card) this morning to remove the frosty coating on my car.
I did find some hurricane-force wind reports too, at least gusts. In Atlantic Canada primarily.

Grand Etang, NS (on Cape Breton) - gust of 156 km/h (97 mph)
St. Lawrence, NL - gust of 135 km/h (84 mph)
Cape Race, NL - gust of 133 km/h (83 mph)
Wreckhouse, NL - gust of 143 km/h (89 mph)
St. John's Airport, NL - gust of 122 km/h (76 mph)
The NHC has released its reports on Hurricane Stan & Tropical Storm Tammy. (www.nhc.noaa.gov/2005atlan.shtml?) Stan didn't kill thousands; the actual number is around 80.
It nearly happened here Link
The report on the Halloween Storm (link in 3rd comment) states that it was the 8th hurricane & 34th tropical storm that wasn't named since naming began in 1950. Is there a list & explanation of these storms anywhere?
Hi Dr Master's and Staff,

Thanks for the great work you do here for all of us!!!

Happy Valentine's Day!

Florida Hazardous Weather Awareness Week is this week (13-17 Feb 06). Now is an excellent time to learn how to be weather safe in Florida. Our spring severe weather season usually begins in late February and ends around mid-April. The state-wide tornado drill is Wednesday 15 Feb 06 and includes many schools. Information on tornadoes, severe thunderstorms, and all our main weather hazards is available at the Florida Hazardous Weather Awareness Week website. The hazards include lightning, marine hazards, rip currents, tornadoes, thunderstorms, hurricanes, flooding, temperature extremes, and wildfires. This website especially contains materials appropriate for teaching weather safety to children and students.


I updated my blog with a condenced version of this big PDF file. Including things this native of the state didn't know. Though one would need to visit the website for the children's hazardous weather teaching activities.

Blizzicane's we should check on all known Nor'Easters that have come close to this
"The NHC has released its reports on Hurricane Stan & Tropical Storm Tammy. (www.nhc.noaa.gov/2005atlan.shtml?) Stan didn't kill thousands; the actual number is around 80."

The death toll for Stan is somewhat arbitrary. Thousands did die, but both Stan and a large storm system to the north were causing the rains that caused massive landslides, etc. There is no good way to tell the tolls of the two storms apart fully.
By the way, Fred is correct. The hurricane I posted above formed in the middle of the dying Perfect Storm.

Which, by the way, is a great book - HIGHLY reccommended.
For those who'd like to debate global warming, SnowFire has posted an excellent blog on the subject.
Amen - I don't have a winter wardrobe, so I was in shorts today. It was 39 degrees when I went outside.

I wasn't cold (???).
Good evening everyone,

Still no freeze for Orlando, as the temperature at Orlando International Airport dropped to 33 degrees (only 1 degree away though!). So the city still hasn't recorded a freeze since the famous January 24th 2003 freeze event. However, I experienced a hard freeze in eastern Orange County, with a morning low of 25 degrees, tying the coldest temperature ever recorded since I have lived in central Florida (tied with January 24th 2003). Most places did drop below freezing across central Florida, with numerous areas falling into the upper to mid 20s. Ocala dipped to a bone-chilling 20 degrees, while some spots in rural Volusia, Lake and Marion county also reached the lower 20s.

Hope everyone has a great night,

Blizzicanes eyyy! So would it be safe to classify Wilma at it's peak intensity a Hurrinado?
Great Picture BTW FUBFEE, best one I have seen yet.
Actually it would be classified as a "Hurrispout". Hurrinado sounds better though. Gotta love the term "Blizzicane" Kudos Jeff.
Hey Colby~ i've been tracking that Weather Modification bill (info about it as well as link to all state senator's e-mail addresses are at the bottom of my blog). Pretty shocked to see it make it past comittee intact, then read several indications it's fast tracked to get through senate, house & into law. Absolutely nothing has been said by the mainstram media on the matter, that i've seen (after searching). Last week the Weather Modification Association seemed to have inside info that they were gonna try to get it passed by senate that week, though i don't think it came up yet.

What really bothers me among other things about the bill, is the lack of oversight. it would be a small committee in charge of weather modifications~ well here~
(1) IN GENERAL- The Board shall consist of 11 members appointed by the Secretary of Commerce, of whom--
(A) at least 1 shall be a representative of the American Meteorological Society;
(B) at least 1 shall be a representative of the American Society of Civil Engineers;
(C) at least 1 shall be a representative of the National Academy of Sciences;
(D) at least 1 shall be a representative of the National Center for Atmospheric Research of the National Science Foundation;
(E) at least 2 shall be representatives of the National Oceanic and Atmospheric Administration of the Department of Commerce;
(F) at least 1 shall be a representative of institutions of higher education or research institutes; and
(G) at least 1 shall be a representative of a State that is currently supporting operational weather modification projects
~where's agriculture, enviroment & the public?
Thanks for the heads-up skypony, looks like a railroading job (ie. railroading it thru congress)
Hurrinado -- that's great! ;-)
Not a very good way of doing things imo Skypony. We, instead of listening to the top climate scientists and every other country about the issue of global warming and cut back emissions, instead take the 'easy' route and dont directly stop the problem. There is only a little bit we can do to modify the weather with these new monifications, when really we can most likely stop the WHOLE problem by cutting our emissions.
Just in case you havent heard yet, the Blizzard of 2006 was a Category 3 storm on the NESIS.

Probably the reason for it just being a 3 and not a 4 is the heavy snowfall (10+ inches) didnt fall over an incredibly large area.
Sorry if this photo has been posted, but another look at the 'eye of the storm'

Eye of the Blizzard
Great Pic RL3AO but, if you scroll down to FUBFEE's pic it is much better at depicting the so called eye, best I have seen.
The most apparent image was just before and during sunrise on the east coast. I don't think a better picture could have been taken.
36. j0hn
A month ago Dr Jeff Masters said:
How strange is this winter's warmth? Duluth, Minnesota, whose average low temperature is 0 F in January, has not recorded a low temperature below 3 F this month. The record fewest January days Duluth has had a sub-zero temperature is three days (1898). I wouldn't be at all surprised if Duluth winds up with no sub-zero temperatures this month.

Well, it looks like sub zero temps are finally coming to Duluth.

atmosweather mail for you
I didnt notice that eye there when it happend. Very interesting to say the leaste.

Can anyone tell me if the average number of Nor'easters are on the rise or falling. It feals like they dont happen as often as they use to.
You can have your sub zero temps, looks like the mid 70's are back to Florida and 80's and Sunny Sat and Sun. Great thing about Florida weather is you know great weather is always right around the corner.
Some sort of eye-like feature is quite common in extratropical systems - Delta, Epsilon, and Zeta all had them before transitioning.
41. Inyo
I think any form of weather modification at this point is a very bad idea.
Thanks Progressive, but I can't take credit, I pulled it from an other thread. Anyway, Here is a good comparison storm, Dec 6th 2003. Up to 20"inches fell in my area during this one.

Skypony, you are looking at an older version of the bill. The version I saw on govtrack.us has that list crossed out (along with everything else from the original wording of the bill). These are the new sections pertinent to the committee:

Section 4(b) MEMBERSHIP.The Weather Modification Subcommittee shall include representatives from appropriate Federal agencies, including the National Oceanic and Atmospheric Administration, the National Science Foundation, and the National Aeronautics and Space Administration.
(c) CHAIRS OF THE WEATHER MODIFICATION SUBCOMMITTEE.A representative from the National Oceanic and Atmospheric Administration and a representative from the National Science Foundation shall serve together as cochairs of the Weather Modification Subcommittee.


Section 5(b) MEMBERSHIP.
(1) COMPOSITION.The Board shall consist of 9 members, each with a field of expertise in atmospheric science or civil engineering relevant to weather modification, and appointed by the Director of the Office of Science and Technology Policy as follows:
(A) At least 1 member shall be a representative of the American Meteorological Society.
(B) At least 1 member shall be a representative of the American Society of Civil Engineers.
(C) At least 1 member shall be a representative of the National Academy of Sciences.
(D) At least 1 member shall be a representative of institutions of higher education or research institutes with experience in the field.
(E) At least 1 member shall be a representative of a State organization that is currently supporting operational weather modification projects.

That looks like even less oversight to me..... Time to write McCain....
45. dcw
Just a thought - isn't less government oversight a *good* thing? :P
That question depends on one's political leanings. There is always an issue with more or less gov oversight.
Less oversight by folks what might have a clue as to what they might be doing and more by government types that have no clue is bad.
Oops, sorry.... hit the post key before I was finished.

With something as potentially dangerous as weather modification (at least the larger scale efforts) I would prefer more oversite by scientists and less by officals being pressured to "DO SOMETHING" about weather folks don't like.
Tropical Storm Delta update is out by the nhc and they are all most done
Just a quick FYI I posted some more pics today..

Some more Satellite images of "The Great Blizzard of 2006" what NOAA is now calling it:Link
Here is the Blizzard of 2005:Link

Looks similar as was the dumping.
Tropical cyclones are not the only warm-core systems! Why must we speak of any warm-core system as 'tropical'? Polar lows are also warm-core (and they often have eyes, too)
Delta should have been upgraded to a hurricane IMO...I guess they were being conservative based on the lack of land data until it hit the Canary Islands (although the damage there was definitely consistent with a Category 1 hurricane, not a tropical storm). The pressure of 980 mb is also too low for its intensity - more in line with an 85-90 mph storm.
Dr. Masters,

[sarcasm follows]

I regret to inform you that you are fired. It is now 8:30AM on the Pacific Coast and today's blog has yet to be published. This is totally unacceptable. You obviously don't realize that my mornings revolve around reading your blog. Please pack your personal belongings. Building security will be there shortly to escort you out.

By the way, even if you are sick I still expect you to post a blog regarding how your cold could have been caused by global warming - charts and spreadsheets are optional.

Thank you,
LOL come on hes got a family which is more inportant
More important to us? :-)
FtWaltonBch~ Thanks for the correction, if you could throw me a link. The i one posted on here earlier, i'd googled in lastnight, seemed slightly different (thing on bottom saying it was to be inacted OCT 1, 2005). I've had a link in my blog to GovTrack, it has 11 members instead of 9 too. & everything (what little there is said it wasn't changed at all except for the title~ Amend the title so as to read: ``To establish a coordinated national weather modification research and development program, and for other purposes''.
colby wrote: Just a thought - isn't less government oversight a *good* thing? :P

Not when we're talking about a government weather-modification program. And really, the discussion is about non-government oversight (i.e. from scientists and others outside of the gov't) of a government program.
I cheated and followed Colby's link......
Skyepony, I just did some digging. If you read the text file on govtrack.us the first seven and change pages are the /old/ bill. Near the top of page 8 you can see that the section numbers start over. /That's/ the current bill. The PDF makes that clear by having the first part typed in struck-out text.
On Thomas's it was a little clearer~ there are now 2 versions of the bill~Link. The 2nd one part of which you posted said it had been reported in senate, so perhaps the hearings have begun?

Besides the bill being pretty well changed this was added~ The heads of the departments and agencies of the United States and the heads of any other public or private agencies and institutions that receive research funds from the United States related to weather modification shall, to the extent possible, give full support and cooperation to the Weather Modification Subcommittee.

One of the only things unchanged was the title amendment~ other puposes? What's that about?
While it is true that not all warm-core systems are tropical, all warm-core systems that the U.S. is going to deal much with are.
ProgressivePulse wrote:

"You can have your sub zero temps, looks like the mid 70's are back to Florida and 80's and Sunny Sat and Sun. Great thing about Florida weather is you know great weather is always right around the corner."

Yup...we may get a chiller from time to time here in Tampa, but we bounce back quickly...looks like it's gonna be sunny with highs around 80 and lows around 60 for at least the next week or so...not bad for February...ahhhhh...gotta love Florida!
Dr Master's ~I'd love to hear your take on the subject...anything brought up at the WMS meeting?

I dug around for articles on th weather modification bill~ to be fair one from each side of the fence~ FOX NEWS & News With Views. Also how it's related to the chemtrails, since i brought that up the otherside of weather modification & chemtrails would be weather wars.

While there ran across this about the recent blizzard being arranged by homeland security, to add urgency to the matter!lol

My blog made the 2nd page of google on the matter, guess i got too update it with the 2nd version of the bill. Thanks for helping me keep up to date info out there ya'll.
This couldn't be anything farther from the truth. I can't believe a PhD would post such incorrect meteorology, and 50 suckers bought off on it. How one can mistake a dryslotted extra-tropical cyclone that BARELY met blizzard criteria for a warm core system is beyond me.

This system didn't have ANY hurricane-like characteristics:

1.) Wind maxima around the center. NO. Wind maxima were WELL displaced to the NW of the cyclone, as is the expected behavior with the gradient maximized between the cyclone and polar/arctic high pressure to the north. Nevermind the fact that hurricane force winds weren't observed anywhere (even remotely close) -- again this system BARELY met blizzard criteria as it was.

2.) Deep convection around the center. NO. The satellite image Jeff uses as his own example clearly shows nothing more than low level stratus/strato-cumulus around the exposed low level center. Towering Cu, cumulonimbus non-existant. Cirrus anvils? Nada.

3.) Eye like feature around the center? NO! This is anything but an eye. It's is the expected representation of an extratropical cyclone with pressures below ~990mb. The same mid-upper level dry slotting that completely eroded this system from the SW leads to large scale subsidence as the system occludes. If a hurricane entrained this much dry air, it wouldn't be a hurricane!

These systems don't deepen from massive latent heat release from 50 degree water!! LOL!!! The process here is simple with the strong thermal gradient along the edge gulf stream instead offering a perfect baroclinic zone for systems to deepen.

This system did not deepen like other Nor'easters because it moved over "cooler" water slightly NW of the gulf stream. Those systems intensify more quickly only fractionally because of warmer water, but of MUCH greater reason, the increased low level thermal gradient and strongly cyclonic curved upper jet streaks that accompany a southeast coastal low. This system was dry slotted with a very STRAIGHT jet sreak.

Dr. Masters, please try to use a bit more basic thermodynamics and dynamics in your blogs. Overall they're very good, but in this case you blew even the most basic understanding of our science.