Dr. Jeff Masters' WunderBlog

Blizzicanes

Posted by: Dr. Jeff Masters, 03:24 PM GMT on februarie 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

Categories: Winter Weather

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1. ForecasterColby 03:43 PM GMT on februarie 14, 2006
Interesting - thanks, Dr. Masters.

2. Merovingian 03:57 PM GMT on februarie 14, 2006
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)

3. ForecasterColby 04:02 PM GMT on februarie 14, 2006
It's happened, Merovingian. Link

4. oriondarkwood 05:09 PM GMT on februarie 14, 2006
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) http://en.wikipedia.org/wiki/Great_Lakes_storm_of_1913 Member Since: iulie 5, 2004 Posts: 51 Comments: 41

5. Trouper415 05:09 PM GMT on februarie 14, 2006
Great job Dr. Masters on this one. And a great pic of that storm Colby. Giants in 06 Member Since: septembrie 22, 2005 Posts: 5 Comments: 637

6. fredwx 06:06 PM GMT on februarie 14, 2006
ForecasterColby 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. Member Since: iunie 8, 2005 Posts: 221 Comments: 261

7. arcturus 06:07 PM GMT on februarie 14, 2006
Very interesting, thanks Dr.Masters. Blizzicane is a better sounding term than snowcane too.

8. TampaSteve 06:23 PM GMT on februarie 14, 2006
Blizzicane...I like it... My brother lives in NYC...they got buried...27 inches of snow...glad I moved to Florida...

9. fredwx 06:29 PM GMT on februarie 14, 2006
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. Member Since: iunie 8, 2005 Posts: 221 Comments: 261

10. CrazyC83 07:07 PM GMT on februarie 14, 2006
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) Member Since: septembrie 19, 2005 Posts: 0 Comments: 142

11. gippgig 08:58 PM GMT on februarie 14, 2006
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. Member Since: decembrie 5, 2005 Posts: 0 Comments: 56

12. FUBFEE 09:03 PM GMT on februarie 14, 2006
It nearly happened here Link

13. gippgig 09:13 PM GMT on februarie 14, 2006
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? Member Since: decembrie 5, 2005 Posts: 0 Comments: 56

14. seflagamma 09:30 PM GMT on februarie 14, 2006
Hi Dr Master's and Staff, Thanks for the great work you do here for all of us!!! Happy Valentine's Day! Gamma Member Since: august 29, 2005 Posts: 287 Comments: 40512

15. Skyepony (Mod) 09:39 PM GMT on februarie 14, 2006
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. http://www.floridadisaster.org/eoc/eoc_Activations/Wilma05/Reports/HurricaneHerald72.pdf 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. Member Since: august 10, 2005 Posts: 145 Comments: 29993

16. TheSnowman 10:31 PM GMT on februarie 14, 2006
Blizzicane's we should check on all known Nor'Easters that have come close to this

17. ForecasterColby 11:27 PM GMT on februarie 14, 2006
"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.

18. ForecasterColby 11:28 PM GMT on februarie 14, 2006
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.

19. ForecasterColby 11:47 PM GMT on februarie 14, 2006
For those who'd like to debate global warming, SnowFire has posted an excellent blog on the subject.

21. ForecasterColby 12:04 AM GMT on februarie 15, 2006
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 (???).

22. ForecasterColby 12:09 AM GMT on februarie 15, 2006
Check out this weather modification bill

23. atmosweather 12:18 AM GMT on februarie 15, 2006
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, Rich Member Since: septembrie 24, 2005 Posts: 33 Comments: 9265

24. KatrinaRitaWilmaZeta 12:27 AM GMT on februarie 15, 2006
atmosweather MAIL FOR YOU GET BACK TO ME THANK YOU

25. ProgressivePulse 12:34 AM GMT on februarie 15, 2006
Blizzicanes eyyy! So would it be safe to classify Wilma at it's peak intensity a Hurrinado? Member Since: august 19, 2005 Posts: 5 Comments: 4443

26. ProgressivePulse 12:35 AM GMT on februarie 15, 2006
Great Picture BTW FUBFEE, best one I have seen yet. Member Since: august 19, 2005 Posts: 5 Comments: 4443

27. ProgressivePulse 01:09 AM GMT on februarie 15, 2006
Actually it would be classified as a "Hurrispout". Hurrinado sounds better though. Gotta love the term "Blizzicane" Kudos Jeff. Member Since: august 19, 2005 Posts: 5 Comments: 4443

28. Skyepony (Mod) 01:13 AM GMT on februarie 15, 2006
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? Member Since: august 10, 2005 Posts: 145 Comments: 29993

29. phillyfan909 01:50 AM GMT on februarie 15, 2006
Thanks for the heads-up skypony, looks like a railroading job (ie. railroading it thru congress)

30. phillyfan909 01:53 AM GMT on februarie 15, 2006
Hurrinado -- that's great! ;-)

31. Trouper415 02:00 AM GMT on februarie 15, 2006
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. Member Since: septembrie 22, 2005 Posts: 5 Comments: 637

32. RL3AO 02:18 AM GMT on februarie 15, 2006
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.

33. RL3AO 02:23 AM GMT on februarie 15, 2006
Sorry if this photo has been posted, but another look at the 'eye of the storm' Eye of the Blizzard

34. ProgressivePulse 02:38 AM GMT on februarie 15, 2006
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. Member Since: august 19, 2005 Posts: 5 Comments: 4443

35. ProgressivePulse 02:45 AM GMT on februarie 15, 2006
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. Member Since: august 19, 2005 Posts: 5 Comments: 4443

36. j0hn 03:00 AM GMT on februarie 15, 2006
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.

37. KatrinaRitaWilmaZeta 03:06 AM GMT on februarie 15, 2006
atmosweather mail for you

38. lightning10 03:39 AM GMT on februarie 15, 2006
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. Member Since: noiembrie 24, 2005 Posts: 41 Comments: 629

39. ProgressivePulse 04:53 AM GMT on februarie 15, 2006
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. Member Since: august 19, 2005 Posts: 5 Comments: 4443

40. ForecasterColby 05:02 AM GMT on februarie 15, 2006
Some sort of eye-like feature is quite common in extratropical systems - Delta, Epsilon, and Zeta all had them before transitioning.

41. Inyo 08:06 AM GMT on februarie 15, 2006
I think any form of weather modification at this point is a very bad idea. Member Since: septembrie 3, 2002 Posts: 42 Comments: 765

42. FUBFEE 11:08 AM GMT on februarie 15, 2006
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. Link

43. FUBFEE 11:45 AM GMT on februarie 15, 2006
Link

44. FtWaltonBch2Tucson 12:08 PM GMT on februarie 15, 2006
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. and: 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.... Member Since: ianuarie 9, 2006 Posts: 0 Comments: 21

45. dcw 12:11 PM GMT on februarie 15, 2006
Just a thought - isn't less government oversight a good thing? :P

46. FUBFEE 12:39 PM GMT on februarie 15, 2006
That question depends on one's political leanings. There is always an issue with more or less gov oversight.

47. FtWaltonBch2Tucson 01:00 PM GMT on februarie 15, 2006
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. Member Since: ianuarie 9, 2006 Posts: 0 Comments: 21

48. FtWaltonBch2Tucson 01:10 PM GMT on februarie 15, 2006
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. Member Since: ianuarie 9, 2006 Posts: 0 Comments: 21

50. KatrinaRitaWilmaZeta 01:29 PM GMT on februarie 15, 2006
Tropical Storm Delta update is out by the nhc and they are all most done

51. oriondarkwood 01:46 PM GMT on februarie 15, 2006
Just a quick FYI I posted some more pics today.. http://tinyurl.com/dget7 Member Since: iulie 5, 2004 Posts: 51 Comments: 41

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