February 2019 Winter Speculation

[Carvers Gap]

MRX with another great write-up(morning disco) on the potential for moderate to heavy periods of precip over the next week.

.LONG TERM...(Saturday night through Thursday)...
The battle between the approaching Spring season and Winter will
be engaged in the vicinity of the Southern Appalachians over the
long term period as the sub tropical high sets up over the Western
Atlantic around the Tropic of Cancer. Several waves of low
pressure will ride from southwest to northeast along a quasi-
stationary polar front generating the possibility of more flooding
in our rain soaked region as moderate to sometimes heavy bouts of
rain build across the region with each passing wave. It must be
stated that there are subtle differences between the Canadian,
European, and American models with timing and axis of greatest
lift and deepest moisture. However, it appears the first wave will
be building into the region later Saturday night through Sunday
night with isentropic lift moisture increasing with the shot at a
little better qpf across the southern third of the forecast area
impacting Southeast Tennessee and Southwest North Carolina. This
wave moves away through the day on Monday allowing for a bit of a
break in the action. This later part of the extended forecast may
be the more concerning part in terms of some excessive rainfall as
a long wave trough amplifies across the Western United States
while the sub tropical high refuses to yield position Tuesday
through the end of the week. This pattern allows for strengthening
moist southwesterly flow off the Pacific Ocean and in the lower
levels off the Gulf of Mexico Tuesday into Thursday. This moist
airmass will be lifted in the presence of a slow moving frontal
boundary/low level trough with the best likelihood for higher pops
extending from Tuesday into Wednesday night. Some good news is
that with such a healthy southerly component to the mean flow,
temperatures are expected to be relatively mild with almost all
the precipitation being liquid.

[Holston_River_Rambler]

Euro keeps upping totals. Hour 240 total precip. 

12z vs 0z. 

 

I think it has to be somewhat overdone, but even cut by 1/3rd these totals would be a lot for 10 days. 

 

[dwagner88]

45 minutes ago, Holston_River_Rambler said:

Euro keeps upping totals. Hour 240 total precip. 

12z vs 0z. 

 

I think it has to be somewhat overdone, but even cut by 1/3rd these totals would be a lot for 10 days. 

 

It’s worth pointing out that it is still raining heavily in the last frame on the euro. Crazy stuff from the models. Hope it’s wrong. 

[weathertree4u]

1 hour ago, dwagner88 said:

It’s worth pointing out that it is still raining heavily in the last frame on the euro. Crazy stuff from the models. Hope it’s wrong. 

Hope that is wrong. Aren't we due for a dry pattern? Seems like we have had several wet years here!

[janetjanet998]

it looks 

2 hours ago, Holston_River_Rambler said:

Euro keeps upping totals. Hour 240 total precip. 

12z vs 0z. 

 

I think it has to be somewhat overdone, but even cut by 1/3rd these totals would be a lot for 10 days. 

 

it looks like the 00z run has the second slug more south sparing the OHIO valley but overlapping with the first slug ...

so looks like two choices...

1) major problems over a wide area (you guys and OH valley) if the firehouse moves around

2) extreme problems over a smaller area (you guys)

in the may 2010 TN floods.,.an amazing 600,000 cfs was being pumped out of the tVA watershed at Kentuckey  and Barkley at one point

the OH river wasn't in flood ..the outflow raised the OH river at cairo IL form something like 30 feet to 43 feet...

without any rain factored in..the OH river is expected to crest there at 52 feet and hold steady for about a week, and hold above 47 feet the rest of the month.. (record is 61.7 feet in 2011)

lake cumberland rise has slowed to a crawl about .01 per hour with 28,000 cfs outflow. (738..71) .I suspect it will crest today and then start falling if they hold that outflow at 28,000 cfs )  which is a high flow ....not sure they will with the rain coming in because of downstraem issues

Local dams to release less water, hope to reduce flooding impact downstream

 

U.S. Army Corps of Engineers Operations Manager Mike Looney says over the past several days they’ve been pushing a lot of water through Barkley Dam.

“If you put a basketball in a box, that’s about a cubic foot. So, there are 150,000 boxes with basketballs or water going through the spillway section every second,” says Looney. “What we have been doing with Kentucky and Barkley Lakes is an aggressive spilling operation moving water out of the lake in order to position the lakes where we can continue to start holding water back as the crest approaches Paducah and Cairo, Illinois.”

As the Ohio River reaches its peak, Looney says less water will be released out of the dams, causing lake levels to rise above typical summer levels. He says that should also help reduce the impact of flooding downstream.

“There’s really no such thing as flood proofing anything,” says Looney. “We can manage the risk involved with flooding, and hopefully what we intend to do is minimize the damage caused by the high water.”

It’s a similar story over at Kentucky Dam. Tennessee Valley Authority spokesperson Travis Brickey says come Friday morning, they will be storing water to help reduce the impact downstream. Because of this, he says water levels at Kentucky Lake are also expected to rise above summer pool.

https://www.wpsdlocal6.com/2019/02/14/local-dams-to-release-less-water-hope-to-reduce-flooding-impact-downstream/

[Carvers Gap]

2 hours ago, dwagner88 said:

It’s worth pointing out that it is still raining heavily in the last frame on the euro. Crazy stuff from the models. Hope it’s wrong. 

Agree. Yes, we want model output to be wrong for sure.  Most models have been very consistent with heavy amounts.  As MRX has noted, the axis is still moving a 100-250 miles north and south from run to run and from model to model.  Even if those numbers were cut in half, still fairly significant amounts.

[AMZ8990]

I can’t help but think how epic last year would of been had we had this pattern of precipitation during our epic January cold spell in 2018.  We would of seen some huge snow storms had it happened. As far as right now,  I fear for everyone with river front properties as they stand to have some serious problems if these flooding concerns happen as previewed. 

[janetjanet998]

the 12z models seem to have ticked SE with the EURO still with the most NW path

every drop of water that falls south of the TN River watershed deeper into GA/AL rather then the OH river watershed is better news i guess

 

 

[Carvers Gap]

This may be of little consolation to our forum, but I have been catching-up on my fishing haunts out West today by reading wx reports and fishing reports.  In Montana and Wyoming there have been at least a couple of big storms during the past couple of weeks.  I think Clark, WY, reported a wind speed of 114 mph this week.  Several areas are saying that drifting snow has been a real issue across many areas of Wyoming with multiple road closures.  Snowpacks for the Yellowstone National Park area have surged to 100+% of normal after a slow start.  Last winter was a banner snow year in the northern Rockies which corresponded to La Nina.  This winter was expected to be a low water year.  Surprise! Many of us have commented that certain facets of this winter have been similar to La Nina.  The increasing snowpack of the northern Rockies would be yet another confirmation of that collective hunch.

[Carvers Gap]

Not that it matters...just a brief LR note in the midst of important flooding discussion.  The 12z GEFS, GEPS, and EPS seem to be slowly moving forward a flip to an eastern trough.  The GEFS at 12z was a fairly significant break from previous runs as it decays the SER much more quickly than the other global ensembles.  We have been fooled by this before....things getting pushed back ad nauseam.  The switch is now projected in the d12-13 range instead of being held at d14-15.  Not calling for winter weather, just noting that the switch has moved forward in time a bit.  The good thing about the decay of the SER is that it would at least likely slow down the fire hose that has been pointed at this forum are for the past few weeks.  That change may or may not increase our chances for winter weather, but it would at least realign the relentless pattern of heavy rain.  Fingers crossed.  

[nrgjeff]

In the short-term, looks like snow for Kentucky! Surface winds are advecting in cold dry air. Shallow front just arrived, so ice first. Then snow esp north away from Tenn. Light snow should get across to the KY/VA and WV/VA borders early Saturday, higher terrain.

Agree with @Carvers Gap about the La Nina signature out West, probably related to stubborn Indonesia convection, but it is complex chaos too. Should be a true cold front end of the month, but I will move to the elephant in the room.

Next week looks like the real deal with rain. Rivers are already up. Ohio River concerns weigh downstream. In both regions we all hope the stationary front wiggles elsewhere.

It is a balancing act, but many talented people are working it at both the Corps and TVA.

12Z ECMWF and ICON remain bullish QPF. Both backed off slightly, but still a lot of rain. Much will depend on frontal position and forcing, along with track of each wave.

If QPF forecasts don't back off by Sunday or Monday, an event thread is probably warranted. 

Huntsville NWS went ahead and released the WPC QPF chart through Day 7. Issued Friday morning.

[Carvers Gap]

3 minutes ago, nrgjeff said:

In the short-term, looks like snow for Kentucky! Surface winds are advecting in cold dry air. Shallow front just arrived, so ice first. Then snow esp north away from Tenn. Light snow should get across to the KY/VA and WV/VA borders early Saturday, higher terrain.

Agree with @Carvers Gap about the La Nina signature out West, probably related to stubborn Indonesia convection, but it is complex chaos too. Should be a true cold front end of the month, but I will move to the elephant in the room.

Next week looks like the real deal with rain. Rivers are already up. Ohio River concerns weigh downstream. In both regions we all hope the stationary front wiggles elsewhere.

It is a balancing act, but many talented people are working it at both the Corps and TVA.

12Z ECMWF and ICON remain bullish QPF. Both backed off slightly, but still a lot of rain. Much will depend on frontal position and forcing, along with track of each wave.

If QPF forecasts don't back off by Sunday or Monday, an event thread is probably warranted. 

Huntsville NWS went ahead and released the WPC QPF chart through Day 7. Issued Friday morning.

Thanks for the post/update and agree w the bold as well.  Those precip amounts form the Huntsville site would be significant without saturated ground and full rivers.  Looks like a good chunk of that falls within the Tennessee River watershed.   I agree....hope that front wiggles elsewhere.  

[janetjanet998]

10 inch contour now showing up on updated WPC 7 day totals over NE AL area

[Holston_River_Rambler]

18z Euro even further south with the aim for the  axis of heaviest snowfall for S. KY. 10 hours will tell the tale. 

 

[John1122]

It's down to 42 degrees here, so the temp is definitely trending downwards. 

[jaxjagman]

Back in 1984 we had a SSWE almost  the same exact date as this date as this one,Dec 31st this was in a weak LaNina,the following month in Jan 1985 Nashville hit it's all time record low of -17..This year we are in a ElNino.Shows you Mother Nature don't play nice with SSWE's.This season should also show you not all Modoki's mean cold weather

[AMZ8990]

1 hour ago, Holston_River_Rambler said:

18z Euro even further south with the aim for the  axis of heaviest snowfall for S. KY. 10 hours will tell the tale. 

 

Winter Weather Advisories up for muliple counties in the upper north west corner of Tennessee.  Calling for freezing rain up to .10 of an inch.  Could get dicey tonight for our northern forum folks between union city  and Clarksville.  

[John1122]

57 minutes ago, jaxjagman said:

Back in 1984 we had a SSWE almost  the same exact date as this date as this one,Dec 31st this was in a weak LaNina,the following month in Jan 1985 Nashville hit it's all time record low of -17..This year we are in a ElNino.Shows you Mother Nature don't play nice with SSWE's.This season should also show you not all Modoki's mean cold weather

The sad thing is the polar vortex descended again like it did in 1985 but instead of setting up over northern Ohio it was west and that is why it was record cold in the midwest. It's been a brutal winter 250 miles n and nw of our forum area. 

You know much more about enso than me, but I've read that this didn't end up being a Modoki for the most part. 

[jaxjagman]

The Euro is slower than the GFS..It really pumps up the LLJ during Tues evening into Wed morn as it shows the warm front lifting into the lower OV.With this it even has capes 500+ with plenty of shear to work with into the Valley.The Euro has some large hodos into Nashville.Wouldn't be surprising to to see a quick spinner somewhere in the Valley . also plenty of KI and showalter right now for thunderstorms,as to how clouds and rain effects things is another thing.The other concern will be with the Euro as the LLJ strenghtens into the Valley and lower OV will be some potential wind gust with already a saturated ground could cause tree damage

 

[jaxjagman]

58 minutes ago, John1122 said:

The sad thing is the polar vortex descended again like it did in 1985 but instead of setting up over northern Ohio it was west and that is why it was record cold in the midwest. It's been a brutal winter 250 miles n and nw of our forum area. 

You know much more about enso than me, but I've read that this didn't end up being a Modoki for the most part. 

No, you're right that this more west based .The seasonals totally whiffed though seemingly,this was suppose to be central.east based Nino,never happened.

[jaxjagman]

GFS is still faster@12z Wed the cold front is sweeping through,it doesnt really show the WF getting past N/AL while the Euro is showing this into Ky

[jaxjagman]

This would really annoy me this winter as i've been hoping for a bowling ball coming off this west coast,and here tonight's Euro shows this as it closes off south of the four corners and boogies right into the Tn Valley:(

[Holston_River_Rambler]

Euro is back to nailing the OH Valley watershed now. Totals still similar. 

Meanwhile the SOL SOI continues to plummet. Down to -24.88 today. For the first time in a long time (maybe all winter) the pressure in Darwin is higher than Tahiti. I know it's been negative before, but this is the first time since fall I can remember it being this low. 

[janetjanet998]

of course this all has to go into the oH river at some point

Tennessee Valley Authority
‏
Verified account
 
@TVAnews

More
Up to 8" of rain is forecasted over the next week. We are releasing high flows from the large tributary dams to create as much storage as possible. All 9 dams on the main stem Tenn. River are operating at full turbine capacity and spilling excess water.

 

12z GFS...has the second slug into the OH valley..

then a pattern change after day 9

[janetjanet998]

[janetjanet998]

FLOODING THREAD SPIN OFF

 

[jaxjagman]

The SOI is at today -29.88,that's the most negative i've see it in quite sometime,maybe ever?..lol

[jaxjagman]

Pretty well tells how this winter has been,after all the potential rains without any cold the Euro goes zonal and dry,so done with this winter

[Holston_River_Rambler]

EPS somehow magically changes overnight and shows a few days of a nice looking pattern. Not sure what happened, but instead of showing this at the very end, it jumped to around 10 - 12 days.

 

[Carvers Gap]

I could be wrong...but there looks to be a pattern change or, at the very least, a 2-3 week relaxation of the eastern ridge deluge.  The SOI is way down there today at -35.88.  That is a possible reason for models "adjusting" as they have been doing for a few days.  As Holston noted above, the 500 patterns on the EPS looks chilly towards the very end of the month.  I do not think we see a prolonged winter pattern, but.....we may see more winter wx than we have seen since early December if that look above verifies from Holston's gif.  Latitude matters now with every passing day.  Winter storms generally woefully underperform at this time of the year if they arrive during daylight hours due to the sun's angle/length of day.  So, indeed there are hints that the first couple of weeks of March might give us an outside shot at something to track, at the very least at higher elevations and areas along the KY/TN line and VA/TN line.  John often remarks that our biggest snows occur at the beginning and tail end of the season.  The current pattern is about as hostile as one can get for snow, and it is difficult to see that changing.  However, with wavelengths changing-up and a shake-up in the ridge/trough structure...it is possible for a brief window to open along the eastern seaboard from say days 10-25.  Though this winter has been unremarkable in terms of prolonged winter weather, it would be somewhat remarkable to begin and end the season with nice events.  I am not making that call as models have been notably flip-flopping away from decent looks in the LR.  Anyway, something interesting to watch. What I really want to see tonight from the Weeklies is their teleconnections for late during week 2 and for all of week 3.  The Weeklies have been pretty bad for weeks 4-7.  But their teleconnection package did signal this current warmup while the actual maps did not.  If those teleconnections are favorable, then I might be a bit more on board...but I at least want to see a favorable Pacific setup (PNA or EPO ridge).  CPC ensembles look fairly bleak at the moment, but those can be a bit slow to change.  Anyway, not going to bang the drum too loudly...but a nice, local teleconnection is that it often is pretty cold when UK comes to town(March 2nd this year).   Also, some claps of thunder over the weekend. Let's just hope UT's outside shooting is not as cold as it was at Rupp when the rematch occurs in Knoxville.