Jump to content
  • Member Statistics

    17,588
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Winter Speculation 17/18 -December Thread


AMZ8990

Recommended Posts

2 minutes ago, Carvers Gap said:

Flip or not to flip...that is the question.  The trough should go into the West after the upcoming week with a BIG warmup here.  We broke a record high at TRI a few days ago...that kind of warm air mass.   Now, is that trough a flip or just a temporary change before reverting back to the trough in the East?  There are models that put the trough in the West and lock it in for several weeks...the JAMSTEC might be one of those as it is my understanding that it keeps us in the warm phases of the MJO.  The Weeklies step down to cold beginning the first week of Feb.  The 0z EPS locks the ridge out West during the 10-15 day time frame...but it should break down about a week after that if the past Weeklies were right.  The 0z GEPS is very warm.  The 6z GEFS is less bullish.  So, looks like a trough in the West gets established for a couple of weeks which will lead to very warm temps.  I still like the Jan 20 - Feb 5 time frame.  There is always a chance the models are incorrect, and the 6z GEFS shows exactly how to get cold when it should be warm.  But the EPS has been pretty solid this winter as have the Weeklies.  I think for the time frame that I mentioned above, +5 to +10 seems about right.  So is a 14-21 day warm spell a flip?  Probably not.  But if it locks in, it would be spring here.  I think that unlikely since the base state for winter has been cold so far...and since the Weeklies, which have been very good this winter, do show the trough at 500 returning.  Add in low solar and the -QBO, and high latitude blocking seems likely to continue.  Those ideas have served us well so far.  So, I think "thaw" is probably a good term with the NA pattern balaninc out the pattern with cold and heat.

Thanks for your thoughts. For example, a week ago, I don't recall thinking I was going to have 3" of snow on the ground Saturday morning and the possibility of at least a dusting more Tuesday with a real threat of going negative Tuesday night. Besides, it is not everyday that the NWS in Nashville, typically ultra conservative in the Winter, for good reason, hard to forecast but for them to mention the long range in their morning discussion is unusual at best and to me says that there is at least the chance that the overall patterns holds into February, which by then, we will be on the upward climb toward Spring.

It will be interesting to see how the low solar impacts weather. I know I have posted before about that and that the Nashville area really does not have much in the way of reliable weather records that go back to the last real low solar time period. Although, we do have records going back to the founding of Nashville that indicate that founders were walking across the frozen Cumberland River. The next few years in general should be interesting to say the least. In addition, if you throw in things that are also associated with low solar like increase in volcanism, all we need is one big one to blow during a low solar to have far reaching impacts.

000
FXUS64 KOHX 131133
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
533 AM CST Sat Jan 13 2018

.UPDATE...
FOR 12Z AVIATION DISCUSSION.

&&

.DISCUSSION...

The winter storm that created slick, icy travel for most areas
along and north of I-40 was moving away toward the northeast early
this morning. It appears all measurable precipitation has ended,
with just scattered flurries expected to linger this morning for
the Upper Cumberland. A Special Wx Statement was issued last night
to highlight the hazardous travel, and this statement will be
freshened for the morning. Untreated surfaces will be slow to
improve this morning under cloudy and very cold conditions. Slight
improvement may occur in the afternoon with a few small breaks in
the clouds, but temps will only reach the mid to upper 20s across
the Mid State, so some icy patches will remain along and north of
I-40. Northwest winds will continue in the 10-20 mph range today,
so wind chills will be in the single digits this morning and teens
in the afternoon.

For tonight, the approaching Arctic high pressure will become
centered over the Ohio Valley, extending southward across TN.
This will bring clearing skies with lows mainly in the teens,
except single digits for the areas with snow cover. Wind chills
will be in the singles.

On Sunday, there will be more sunshine, but temperatures will
recover only into the upper 20s and lower 30s. Lows Sunday night
will be around 20 with partly cloudy skies.

For Monday (Martin Luther King Jr. Day) a brief warmup will occur
as south winds develop ahead of an approaching cold front. Highs
will reach the upper 30s to lower 40s. Clouds will increase
through the day, with a chance for afternoon rain or snow showers
over our northwest counties.

Monday night into Tuesday, a cold front / clipper system will
bring another strong shot of frigid air, along with a period of
wintry wx. Snow pops will be increased to likely for most of the
area as the major operational models are in good agreement
indicating almost all snow for precip type, with potential
accumulations in the one half to 2 inch range.

If we do indeed get a fresh coating of snow Monday night through
Tuesday morning, it would help bring what may be the coldest day
or 2 of winter so far. Highs Tuesday are only expected to reach
the teens. Lows Tuesday will drop to the single digits as skies
clear out, but snow cover could allow lows to plummet into the
single digits below zero. Wednesday will bring highs only in the
lower 20s, but perhaps teens again if there is any snow on the
ground.

Looking ahead, there will be a warmup late week as the upper air
pattern becomes less amplified and more wavy. Temps could push
toward 60 next Saturday, before crashing down again with the next
cold shot a day or 2 later. Indices such as the Arctic
Oscillation and North Atlantic Oscillation are trending downward
for late January, indicating at least the potential for continuing
cold air outbreaks. It looks like we could have a lot of winter
to deal with yet.

http://forecast.weather.gov/product.php?site=OHX&issuedby=OHX&product=AFD&format=CI&version=1&glossary=1

https://www.newsmax.com/headline/dark-winter-cold-global-cooling/2014/11/16/id/607672/

http://shewasabird.blogspot.com/2013/05/photo-friday-frozen-cumberland-river.html

 

 

Link to comment
Share on other sites

  • Replies 2.5k
  • Created
  • Last Reply

GFS paints the cold front meh snow scenario Tuesday. Euro clearly has a stronger southern stream, and drops a narrow but notable 2-4 inch swath. Yes 20:1 ratios.

NAM appears to be a compromise. Normally LOL at NAM beyond 60 hours, but it is showing a reasonable blend of the above. Like to see the Canadian more on board, but the NAM is a start. 12Z GFS takes baby steps.

Places like Nashville, Knoxville and TRI are favored at this time - per pattern recognition, regardless of NWP. MEM, HSV, CHA will need a more robust southern stream PVA solution to verify.

Link to comment
Share on other sites

3 hours ago, weathertree4u said:

Thanks for your thoughts. For example, a week ago, I don't recall thinking I was going to have 3" of snow on the ground Saturday morning and the possibility of at least a dusting more Tuesday with a real threat of going negative Tuesday night. Besides, it is not everyday that the NWS in Nashville, typically ultra conservative in the Winter, for good reason, hard to forecast but for them to mention the long range in their morning discussion is unusual at best and to me says that there is at least the chance that the overall patterns holds into February, which by then, we will be on the upward climb toward Spring.

It will be interesting to see how the low solar impacts weather. I know I have posted before about that and that the Nashville area really does not have much in the way of reliable weather records that go back to the last real low solar time period. Although, we do have records going back to the founding of Nashville that indicate that founders were walking across the frozen Cumberland River. The next few years in general should be interesting to say the least. In addition, if you throw in things that are also associated with low solar like increase in volcanism, all we need is one big one to blow during a low solar to have far reaching impacts.


000
FXUS64 KOHX 131133
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
533 AM CST Sat Jan 13 2018

.UPDATE...
FOR 12Z AVIATION DISCUSSION.

&&

.DISCUSSION...

The winter storm that created slick, icy travel for most areas
along and north of I-40 was moving away toward the northeast early
this morning. It appears all measurable precipitation has ended,
with just scattered flurries expected to linger this morning for
the Upper Cumberland. A Special Wx Statement was issued last night
to highlight the hazardous travel, and this statement will be
freshened for the morning. Untreated surfaces will be slow to
improve this morning under cloudy and very cold conditions. Slight
improvement may occur in the afternoon with a few small breaks in
the clouds, but temps will only reach the mid to upper 20s across
the Mid State, so some icy patches will remain along and north of
I-40. Northwest winds will continue in the 10-20 mph range today,
so wind chills will be in the single digits this morning and teens
in the afternoon.

For tonight, the approaching Arctic high pressure will become
centered over the Ohio Valley, extending southward across TN.
This will bring clearing skies with lows mainly in the teens,
except single digits for the areas with snow cover. Wind chills
will be in the singles.

On Sunday, there will be more sunshine, but temperatures will
recover only into the upper 20s and lower 30s. Lows Sunday night
will be around 20 with partly cloudy skies.

For Monday (Martin Luther King Jr. Day) a brief warmup will occur
as south winds develop ahead of an approaching cold front. Highs
will reach the upper 30s to lower 40s. Clouds will increase
through the day, with a chance for afternoon rain or snow showers
over our northwest counties.

Monday night into Tuesday, a cold front / clipper system will
bring another strong shot of frigid air, along with a period of
wintry wx. Snow pops will be increased to likely for most of the
area as the major operational models are in good agreement
indicating almost all snow for precip type, with potential
accumulations in the one half to 2 inch range.

If we do indeed get a fresh coating of snow Monday night through
Tuesday morning, it would help bring what may be the coldest day
or 2 of winter so far. Highs Tuesday are only expected to reach
the teens. Lows Tuesday will drop to the single digits as skies
clear out, but snow cover could allow lows to plummet into the
single digits below zero. Wednesday will bring highs only in the
lower 20s, but perhaps teens again if there is any snow on the
ground.

Looking ahead, there will be a warmup late week as the upper air
pattern becomes less amplified and more wavy. Temps could push
toward 60 next Saturday, before crashing down again with the next
cold shot a day or 2 later. Indices such as the Arctic
Oscillation and North Atlantic Oscillation are trending downward
for late January, indicating at least the potential for continuing
cold air outbreaks. It looks like we could have a lot of winter
to deal with yet.

http://forecast.weather.gov/product.php?site=OHX&issuedby=OHX&product=AFD&format=CI&version=1&glossary=1

https://www.newsmax.com/headline/dark-winter-cold-global-cooling/2014/11/16/id/607672/

http://shewasabird.blogspot.com/2013/05/photo-friday-frozen-cumberland-river.html

 

 

Great find.  The Euro missed the strength of the upcoming/current trough.  It has been pretty solid w the 500 pattern placement of ridges and troughs but has missed the strength of the cold at times.  Yeah, I do think the teleconnections have a chance to line-up pretty well by the end of the month. That would fit pretty well with a an early Feb cool down.  Definitely one of the reasons that I like the weather is trying to learn and figure out how things fit together...and we do have some things that might battle the warm signal during that time frame.  It is likely that the latest warmup reset the timing of the northern and southern systems.  Honestly, it was nice to have warm days this week.  LOL.  This morning was a shock!  Pretty awesome front last night as well.  Often, the only times that I hear that roar is high up in the mountains.

Link to comment
Share on other sites

1 minute ago, Will (little rock) said:

The models look decent for Central-South Arkansas, What are your guy's thoughts?

It's according to which model is right, GFS and you're looking at an inch or so. Euro and you're probably doing a lot better. The main difference between the two is the speed of the front. The Euro is slower and it lets more moisture return across the entire area from Eastern Texas all the was to SWVA.

Link to comment
Share on other sites

8 minutes ago, John1122 said:

In what is becoming a theme it seems, the Euro steps towards the GFS and is much drier than in prior days for next week. We from consistently showing .25-.4 across the area to .10-.20 across the area for Tuesday.

If we can at least keep .10 to .20, and score 20-1 ratios thats still a good 2" to 4" event for most.  We still have a couple days of model runs.

Link to comment
Share on other sites

31 minutes ago, ShawnEastTN said:

If we can at least keep .10 to .20, and score 20-1 ratios thats still a good 2" to 4" event for most.  We still have a couple days of model runs.

I hope we can get high ratios, it's tough to get 20:1. The GFS puts my area at 17:1 and the central valley at 13:1 for the event. Ratio adjusted the GFS puts down about 1-2 max north of 40 from Memphis to Knoxville roughly. Some 3 inch dollops in favored spots. It may be slightly drier than the 12z Euro but by no more than a few hundredths of an inch.  It's all about speed and having time to transport energy. The Euro was allowing that to happen and it lost it. The NAM shows a little more juice but it's the NAM and that's a bias with it, especially at longer range.

I'm going to really hope for a 2-4 inch type event but expect a 1-2 type and feel lucky if that comes to pass with how everything is busting for my area this year.

Link to comment
Share on other sites

1 minute ago, John1122 said:

Weather.us is the place for the Euro if you aren't paying. What he's referring to is the entire country looks to be frigid at day 10. Freezing temps to the Gulf.

Get out of town, let me take a look. Thanks for the link also. But if we have everything pushed so far south, then we are back where we were a couple weeks ago, cold and dry.

Link to comment
Share on other sites

MRX is not impressed at all about the snow totals for the Thurs. system

Snow totals from Tuesday into Tuesday night look
to be around half an inch for most locations, including the East TN
Valley. Portions of the Cumberland Plateau, SWVA, and the higher
terrain of our eastern mountains could see up to 1 to 1.5 inches.
These totals aren`t that impressive but seeing that this system
moves through during the day there could be some travel issues.
Link to comment
Share on other sites

25 minutes ago, bearman said:

MRX is not impressed at all about the snow totals for the Thurs. system


Snow totals from Tuesday into Tuesday night look
to be around half an inch for most locations, including the East TN
Valley. Portions of the Cumberland Plateau, SWVA, and the higher
terrain of our eastern mountains could see up to 1 to 1.5 inches.
These totals aren`t that impressive but seeing that this system
moves through during the day there could be some travel issues.

They must have seen the 18Z GFS. It looks terrible if you like snow.

Link to comment
Share on other sites

The 18z NAM really digs the trough from Canada further west than previous runs (similar to recent Euro runs) and turns the flow straight from the Gulf. I don’t think the NAM is overamped at all if the depiction at 500mb is correct. GFS and most models don’t dig the shortwave as far to the Southwest. It seems the NAM and Euro could be sniffing this one out.

Link to comment
Share on other sites

1 minute ago, 1234snow said:

The 18z NAM really digs the trough from Canada further west than previous runs (similar to recent Euro runs) and turns the flow straight from the Gulf. I don’t think the NAM is overamped at all if the depiction at 500mb is correct. GFS and most models don’t dig the shortwave as far to the Southwest. It seems the NAM and Euro could be sniffing this one out.

I sure hope the NAM and Euro are  on to something. It is a little concerning the the Euro at 12Z was a tad drier than previously. On another note, I don’t even know why I bother with the GFS as bad as it is this year. 

Link to comment
Share on other sites

5 minutes ago, John1122 said:

Yeah, that was it's driest run yet. Gotta love how it snows north of here, northwest of here, West of here, southwest of here, and east and northeast of here. Almost in every direction. 

GFS is pretty balmy in the long range as well; not sure if that is correct, seems like I heard that the NAO was going negative end of month.

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...