Jump to content
  • Member Statistics

    17,587
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

A Few Confererence slides


usedtobe

Recommended Posts

The first slide is a table showing the 10 biggest BOS snowfall seasons since 1950 (left) and the 10 lowest. The seasons in blue are La NIna and those in Red El Nino. The three underlined seasons for the heavy snow years indicate that it was also a top 10 for dca and BOS. The bolded years shared a big year with NYC. BOS and NYC shared 6 years. Note that El NIno years don't really stand out as being any better than la nina or neutral years. Bos also shared 6 top 10 seasons with DEtroit. Miller Bs obviously can do the trick.

post-70-0-78436700-1342462977_thumb.gif

The second slide is a composite showing the 500h anomalies for the big snow seasons (left) and Crappy ones. Those in which CT Blizzard starts going off each potential storm that doesn't make it. Note for the years that Fella would be extremely happy the NAo is negative and there is a big ridge of AK with plenty of northern stream energy on the east side of it. The crummy years tend to have a distinct positive AO with low heights over the high latitudes especially Greenland and Baffin Bay.

post-70-0-98784100-1342463247_thumb.gif

There were 4 years where BOS did not share top 10 snow years with NYC. That composite is a weird on that I wouldn't have thought would produce lots of snow. I decided not to post the composite here as I've got enough other images I want to show. Instead, I'll show the crummy BOS el Nino composite, Ninos that produced less snow than normal for BOS

post-70-0-04484500-1342463727_thumb.gif

You can get a fell for how the AO and PNA impact BOS nino snow looking at the following table. The table shows the number of months during Dec_mar in which the AO and NAO were below -.5 and the number of months that the PNA was positive (a ridge over western North America (the west coast). Note that the years in which the AO had few negative months, the ninos usually sucked.

post-70-0-20270800-1342464078_thumb.gif

Finally, I composited the big snowstorm compositive 12-24 hrs prior to the storm. The storm had to give BOs double figures usually over a foot. there is one image that is a day later on the slide. I'll let Ray or Kevin figure out which one.

post-70-0-88548100-1342464191_thumb.gif

Who says I never look at New England?

Link to comment
Share on other sites

Lol Wes sorry SNE couldn't make it this year. Missed seeing you. Thanks for the shout out above(I think?)

I did miss you but since you were not there, I cracked on you on one or two slides. It probably would have been funnier with you there. We did have BOb who represented your area well. I did miss you, Ray and Ginx.

Link to comment
Share on other sites

Great slides. One thing of note during the severely neg NAO years some of us south of Boston in SNE do pretty well compared to Bos. 09/10 being an example.

NYC often also does well. You probably share about the same number of top 10 years with DCA as does NYC....about 6 of the 10 years were shared. I also did a composite for NYC which might be more closely aligned with you guys. I'm going to post slides for them sometime in the next couple of days. I'll make sure to post something in the New England forum so people can look at those days. The crummy year composites weren't very different from city to city.

Link to comment
Share on other sites

NYC often also does well. You probably share about the same number of top 10 years with DCA as does NYC....about 6 of the 10 years were shared. I also did a composite for NYC which might be more closely aligned with you guys. I'm going to post slides for them sometime in the next couple of days. I'll make sure to post something in the New England forum so people can look at those days. The crummy year composites weren't very different from city to city.

Fantastic, FYI best bass fishing year ever for me! 32 last week.

Link to comment
Share on other sites

Wes,

LOVED seeing this in person last weekend!!! Others did represent SNE, like Amy, Diane, and Mitch as well as Bob. Nothing but positive responses from ALL those in person at Baltimore. You always do a GREAT job!!!

--Turtle

Link to comment
Share on other sites

Points of interest for me (fwi not w)

-- La Nina vs El Nino snow years seem evenly distributed as to whether they were above normal snow totals. Intriguing, the below normal snow years had more El Ninos. I have seen it written before the El Ninos can be a live by the sword, die by the sword, and that certainly holds up. The latter numerics do seem to suggest some indirect link with the AO.

-- The northern tier of the country through New England appear to be more evenly distributed in general as to whether ENSO or the AO dominates the winter character.

-- I found it really interesting that the EPO is suggested as having the greatest magnitude in anomaly during snowier years. I personally have argued in the past that the NAO is 'somewhat' overrated. The trick with the NAO is that larger scale precipitation events (snow or rain regardless) in the winter tend to take place on the index inflection points. Once the NAO achieves either a positive or negative static state, the flow tends to stablize in the form of suppressed flow, or ridging in the east - of course neither being conducive to snow (or rain).

However, and it makes a great deal of intuitive sense to me, if the EPO is statically negative, then a steady diet of NW-->SE moving impulses takes place in the means. In addition, cold loading into the stage regions of the Canadian Shield is in play, where comparatively weaker systems passing near 40N can then avail and bring it down in intervals, setting stage of overrunning, or incorporating into cyclogen...etc... And the NAO, oft' being east based at times anyway, may not even be involved really.

Link to comment
Share on other sites

Points of interest for me (fwi not w)

.........-- The northern tier of the country through New England appear to be more evenly distributed in general as to whether ENSO or the AO dominates the winter character.

-- I found it really interesting that the EPO is suggested as having the greatest magnitude in anomaly during snowier years. I personally have argued in the past that the NAO is 'somewhat' overrated. The trick with the NAO is that larger scale precipitation events (snow or rain regardless) in the winter tend to take place on the index inflection points. Once the NAO achieves either a positive or negative static state, the flow tends to stablize in the form of suppressed flow, or ridging in the east - of course neither being conducive to snow (or rain).

However, and it makes a great deal of intuitive sense to me, if the EPO is statically positive, then a steady diet of NW-->SE moving impulses takes place in the means. In addition, cold loading into the stage regions of the Canadian Shield is in play, where comparatively weaker systems passing near 40N can then avail and bring it down in intervals, setting stage of overrunning, or incorporating into cyclogen...etc... And the NAO, oft' being east based at times anyway, may not even be involved really.

i'd like to see the top ten snowiest years and the amount of months dec-march had epo's > .5 john

Link to comment
Share on other sites

Wes, I really enjoyed your talk. Great job!

One question...I remember you discussing a correlation involving the QBO (at least I think it was) that had a coefficient of ~0.45. Since my memory is a little fuzzy, was this the correlation between the QBO and NAO/AO state or something else? Thanks.

The QBO more or less helps determine the timing of any stratospheric warming events and when it's negative gives you a better chance at an early warming event. I suspect that it also may give such an event a little better chance of propagating downward and influencing the AO as convection near the equator is deeper which probably plays a role in strengthening the brew dobson circulation. Even then you need the EP flux to be pointed towards the poles instead of the equator. Also, an easterly qbo usually only gives you a warming event during a low solar flux period. You can get a feel for how low the correlation is between the QBO and either the NAO or AO byt simply plotting a correlation with the 500h heights during winter.

post-70-0-29115800-1342491557_thumb.gif

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...