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Pattern Oppressive Ornery Obstinate Opposite October

Holy Cow and other statistical animals ...

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Maybe we need a thread for today's threat.

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Mesoscale Discussion 1737
NWS Storm Prediction Center Norman OK
1207 PM CDT Mon Oct 23 2017

Areas affected...Extreme eastern GA...SC...western NC

Concerning...Severe potential...Tornado Watch likely

Valid 231707Z - 231900Z

Probability of Watch Issuance...80 percent

SUMMARY...Severe threat will increase across SC and western NC into
the mid-afternoon hours. Tornado watch will likely be issued by
18-19z to account for this threat.
 
Ended up with 1.72" of rain here. Way off from the original 3.2" forecast, but still welcome rain for sure! Holding in the middle 60s now with peeks of sun at times. Looking forward to the cooler weather this week! GFS sure has been consistent with upper 20s here Sunday Night.... will be interesting to see if it comes to fruition.
 
TDS around Woodruff,SC :(
 
Another storm near Gaffney , tornado warned and two seperate rotations
 
My predicted 2 day rain event , is now not even 10 hours! :(
Starts after sunrise and ends by 3-4 pm! It's gonna have to rain awfully hard to get my 3+ inches of rain!
#BUMMER
1.1 total, better than nothing, but still a bust, with models showing 3+
 
Dang, I love seeing the O line charging south east. There is just no better time of year for me than when the O line is visiting :) And some good fronts come with it. Got a solid 1 1/2 this morning and I was out in it on I 75. Don't think I'll be doing that again. I like an adreniline rush same as the next guy, but I'd rather get it sledding by that bridge abutment, than driving rain blind on an Interstate hwy.. near the big, sprawling city monster.
 
The 00z Gfs still looking like it's trying to break the pattern after next weekend's cold shot. There's really 3 shots then to this 'colder spell', one each progressively stronger... so it's going to almost even out the mean temps here in CHA by the end of OCT. Still, think the month will avg. slightly above. The main difference we're seeing this year compared to last is way more variation in the flow. Hopefully this pattern repeats a couple times in the DJF time frame. Almost assures someone in the SE gets a decent snowstorm and periods of cold, unlike last year.
 
It's dead in here! The big freeze is coming next week! More rain this weekend, some mountain snow, a tropical entity in the gulf, Robert says winter storms are going to start showing up for us in 6-8 weeks!? I mean, where's the chatter?? Weather is about to be lit! :)
 
It's dead in here! The big freeze is coming next week! More rain this weekend, some mountain snow, a tropical entity in the gulf, Robert says winter storms are going to start showing up for us in 6-8 weeks!? I mean, where's the chatter?? Weather is about to be lit! :)
Let's hope the torch isn't about to be lit

Sent from my SM-G920V using Tapatalk
 
A massive earthquake was reported near Mt Agung earlier today, if this volcano erupts before or during winter, and spurs a major eruption, it would impart forcing through radiative imbalances at the top of the Brewer Dobson Circulation and stratosphere that increases the strength of the polar vortex/Northern Annular mode favoring a +AO/+NAO this winter which only would increase the odds of a warm winter this year...

Essentially what allows this to happen is above the level where the aerosols are deposited in the stratosphere during a major eruption, the temperature warms due to the reflection of solar radiation by said aerosols in concert with incoming radiation. The higher temperatures in the stratosphere reverse the poleward temperature gradient (which usually favors increasing temps northward) and therefore due to thermal wind relationships, this temperature gradient reversal increases the westerly wind tendency in the stratosphere, thereby impacting the momentum flux deposition of mid latitude rossby waves s.t. their momentum fluxes can more effectively cross the equator. If these Rossby waves aren't depositing momentum poleward towards the vortex, they can't efficiently decelerate the polar night jet that encapsulates the vortex and mix ozone rich, mid latitude air into the poles (both processes lead to warming of the pole stratosphere which from the hypsometric equation argues for height rises and thus blocking). The warming at the top of the Brewer Dobson Circulation also decreases the efficiency and intensity of the meridional circulation, this also allows the poor vortex to intensify. While interannual variability may be profound the net forcing imparted by a very explosive volcanic eruption is to incubate the polar vortex >>> +AO/NAO >>> higher chance for warm winter. In a background climate that's already skewed towards warm winters we can't afford unfavorable forcing... The volcanic eruption can also accelerate westerly QBO descent on the equator again due to thermal wind relationships... Warming occurs underneath westerly wind descent on the equator. This regime would decrease intraseasonal variance (deamplify the MJO) because the upper tropospheric shear and static stability would be less conducive to on-equatorial convection. However, this would potentially increase the chances for a NINA (which imparts a circulation that reinforces the +NAO & decreases poleward momentum fluxes onto the polar vortex because the mean wave pattern in a NINA destructively interferes with the standing planetary wave configuration).
See Bitner et al (2016) for more info http://onlinelibrary.wiley.com.prox.lib.ncsu.edu/doi/10.1002/2015JD024603/full
 
Seeing low's forecasted 40 degrees for Alex City, so I'm looking at 35-36 here. Aught to be the first woodstove fire of the season.
 
I thought volcanic eruptions helped decrease global temps but guess it depends on where it's located? Mt. Pinatubo certainly helped decrease temps globally.
 
I thought volcanic eruptions helped decrease global temps but guess it depends on where it's located? Mt. Pinatubo certainly helped decrease temps globally.
If there are any variables out there to give us a warm winter, we will have them all! Old or new! :(
 
I thought volcanic eruptions helped decrease global temps but guess it depends on where it's located? Mt. Pinatubo certainly helped decrease temps globally.
Takes a while for the effects to set in, and we'd need a big one, going for a while, to get us snow next year :) I've got a link to a camera on a volcano in Iceland, and check it from time to time, looking for the onset of the next big cool down, lol. All it does is get hidden by rain clouds so far.
 
I thought volcanic eruptions helped decrease global temps but guess it depends on where it's located? Mt. Pinatubo certainly helped decrease temps globally.

I believe eruptions, especially with a lot of sulfur going into the stratosphere, have a net cooling effect. Of these, ones located in the tropics like Agung would generally cool both the N and the S hemisphere. However, I suppose global cooling can still result in some areas that are warmed for periods of time (possibly months or longer) depending on how it changes the pattern? It sounds like Webber is saying that in this case it would strengthen La Niña. A stronger La Niña, itself, would tend to favor a warmer SE this winter vs a weaker La Niña. But it would also favor a colder upper Midwest, n Plains, NW US, and W Canada this winter. Also, if the volcano were to cause a stronger +AO, that would mean a colder Arctic this winter. The net effect on the N Hem should be colder with this setup. Also, keep in mind that a stronger La Niña, itself, is often correlated with a cooler globe.

https://en.m.wikipedia.org/wiki/La_Niña#/media/File:La_Nina_regional_impacts.gif
 
Takes a while for the effects to set in, and we'd need a big one, going for a while, to get us snow next year :) I've got a link to a camera on a volcano in Iceland, and check it from time to time, looking for the onset of the next big cool down, lol. All it does is get hidden by rain clouds so far.

Tony, the weakening sun combined with this potential major volcanic eruption would be interesting to follow globally. It would be nice to at least have sea level fall for a change!
 
The winter of 1991-2, which followed the June huge eruption of Pinatubo, was quite warm in the SE US even though that was El Niño. KATL was +3 for DJF. However, the subsequent two DJFs averaged right at normal there. Food for thought.

Edit: Even if the SE were +3 this winter, that would be MUCH colder than the last one.
 
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The winter of 1991-2, which followed the June huge eruption of Pinatubo, was quite warm in the SE US even though that was El Niño. KATL was +3 for DJF. However, the subsequent two DJFs averaged right at normal there. Food for thought.

Edit: Even if the SE were +3 this winter, that would be MUCH colder than the last one.
Larry,
Ya think?
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Just hoping that we see something equally BN and with some duration, later on ... ;)
 
^Push the 30s SE into Gainesville, the Great Radiator, I'd think.
 
I believe eruptions, especially with a lot of sulfur going into the stratosphere, have a net cooling effect. Of these, ones located in the tropics like Agung would generally cool both the N and the S hemisphere. However, I suppose global cooling can still result in some areas that are warmed for periods of time (possibly months or longer) depending on how it changes the pattern? It sounds like Webber is saying that in this case it would strengthen La Niña. A stronger La Niña, itself, would tend to favor a warmer SE this winter vs a weaker La Niña. But it would also favor a colder upper Midwest, n Plains, NW US, and W Canada this winter. Also, if the volcano were to cause a stronger +AO, that would mean a colder Arctic this winter. The net effect on the N Hem should be colder with this setup. Also, keep in mind that a stronger La Niña, itself, is often correlated with a cooler globe.

https://en.m.wikipedia.org/wiki/La_Niña#/media/File:La_Nina_regional_impacts.gif
Thanks for the explanation Larry. Last thing we need is something that goes against blocking in a winter where it is really needed. I know there are other factors such as the EPO but not sure how that could play a part in a Nina winter?
 
The winter of 1991-2, which followed the June huge eruption of Pinatubo, was quite warm in the SE US even though that was El Niño. KATL was +3 for DJF. However, the subsequent two DJFs averaged right at normal there. Food for thought.

Edit: Even if the SE were +3 this winter, that would be MUCH colder than the last one.
The winter of 91-92 was a great one for snow lovers in GA. I had about 6" from a snowstorm in Jan 92.
 
The winter of 91-92 was a great one for snow lovers in GA. I had about 6" from a snowstorm in Jan 92.

Yep, although it helps a lot to have a near normal or colder winter, 1991-2 is a good example showing some SE areas can get way above normal snowfall from one big storm in a mild winter. Other examples for ATL and other SE locations: 2001-2 and 1951-2. Also, 1999-2000, another mild winter overall, had 2 major ZRs at ATL (and Carolina Crusher was that winter), while the mild winters of 1948-9, 1932-3, and 1881-2 each had a major ZR at ATL.
 
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Further to 6/91 Mt. Pinatubo post:

As I said for ATL, the winter immediately following it (1991-2) was mild but the subsequent two (1992-3 and 1993-4) were right at normal, which made them the two coldest winters since 1987-8 since 1988-9, 1989-90, and 1990-1 were all mild. Also, the 3 winters following the blast all had above average snow at ATL. The 3 prior ones were near normal, below normal and below normal regarding snowfall. Some of that is likely based on randomness of course.

Considering the recent past and what we're up against: IF we can just get a near normal SE winter this winter, I'd consider it a huge victory for cold lovers. A near normal winter is still a real winter (SE style) as far as I'm concerned and it would be way, way colder than last winter. I wouldn't even think about a colder than normal one so much right now so as to prevent the likely disappointment. Now, if we can get a colder than normal Nov and it looks like the Nina is not getting too strong, I'll start entertaining the chance for a cold one.
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I haven't experienced even one colder than normal month here since 1/2016!!
 
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