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Carvers Gap

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  • Four Letter Airport Code For Weather Obs (Such as KDCA)
    KTRI
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    Tri-Cities, TN

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  1. Carvers Gap

    February 2019 Winter Speculation

    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.
  2. Carvers Gap

    February 2019 Winter Speculation

    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.
  3. Carvers Gap

    February 2019 Winter Speculation

    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.
  4. Carvers Gap

    February 2019 Winter Speculation

    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.
  5. Carvers Gap

    February 2019 Winter Speculation

    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.
  6. Carvers Gap

    February 2019 Winter Speculation

    MRX on top of next week.... Continued high rain chances throughout the extended forecast over already soggy soils will lead to an increased risk of flooding next week. Still looks like the next round or wave of rainfall begins Saturday night and through Sunday night. Higher pressure with drier airmass moves in early Saturday evening temporarily behind latest frontal system. However moisture begins to pool to the south ahead of developing low pressure along the gulf coast that then moves northeast towards the Tennessee Valley Sunday. As air is lifted over old frontal system boundary increasing rainfall possible Sunday into Sunday night. This next developing system will move through by early Monday. ECMWF model shows no break but GFS does show about a 12 hour dry period before the front moves back north and then stays near the southern border of Tennessee as a couple of low pressure areas move along the front Tuesday through Wednesday night. Rainfall amounts Saturday night through Sunday night are about one half inch northeast to 1.5 inches in the southwest which is not expected to produce flooding. The latter system is now showing much more rainfall from about 2 inches northeast to as much as 5 inches in the extreme southeast through Thursday morning. The models try to bring the system farther south and east but another wave may bring in more rain at the end of the extended. With the extended period of moderate to possibly heavy rainfall several rivers will likely rise to near or above flood stage by mid of next week.
  7. Carvers Gap

    February 2019 Winter Speculation

    Both the 12z CMC and GFS operationals have incredible amounts of precip. Really hoping those totals have some feedback in them.
  8. Carvers Gap

    February 2019 Winter Speculation

    Hate to beat a dead horse...but MRX is getting out in front of the heavy rain and flooding potential. Here is their graphic and a snippet from their morning disco.... .LONG TERM (Friday through Wednesday)...The main focus of this part of the forecast will be the precip amounts falling over already moist soils. Looks like three waves of precip--Friday/Fri night; Sunday; then the big show Monday night through the end of the forecast. The first couple of events should each stay below 1 inch in general, but the big event will likely produce very heavy rains over part of the area, and possibly repeatedly for some areas. The mid-range ensembles show an axis of heaviest rains over N GA/N AL/SE TN/W NC/W SC and staying over the same areas, but the deterministic GFS/Euro show more active north or south movement of the axis over time, so there may well be some lulls in the precip, but some areas should definitely get some very heavy rains and possible flooding. Between now and when this big event starts, it will be important to watch for changes in the placement of this axis and the placement of the associated frontal boundary. Looking at the contributing components for heavy rains, things are a little more progressive than it might seem at first glance--looks like the heaviest rain rates and flash flooding threats will generally be confined to one 24-hour period--like Tuesday and Tuesday night -or- Tuesday night and Wednesday, etc. However, the river (non-flashy) threat probably will continue through the end of next week for the places under that heaviest precip axis--once again the forecast for this axis may drift north or south in the coming days--still 5-6 days away. Pretty cool airmass over southwest VA some of these nights, but looks like almost all precip will be in the form of rain.
  9. Carvers Gap

    February 2019 Winter Speculation

    The 16d 0z EPS total precip map is not pretty. The 6z GEFS is probably worse. Hopefully this is a bust.
  10. Carvers Gap

    Winter 2018-2019 Observations

    Got ya. Just a difference in definitions...The SoHo has the generation unit area on the left and then to the right a sluice for spilling excess water. Yeah, I don't think the "wooded" emergency spillway(the third one) on the SoHo has ever been used. I can't imagine what type of event would cause that. Whew! Usually if TVA sees a sizable event on the horizon, they push a bunch of water down stream of the area to be impacted and hold water upstream. Wasn't there a dam out in California recently that had to use its overflow spillway and it almost destroyed the dam and blew out large portions of that overflow spill way? I can't imagine what type of rainfall that would require. (And for those new to the conversation....I don't think anyone is talking about flooding of that magnitude.) As for oxygen...TVA has done a great job below Norris and South Holston with the weir dams which help with that in addition to keeping constant flows. Night and day improvements over the past 30-40 years. And as an observation of today's wx....a brisk wind has been blowing all day. It has certainly been nice to see the sun!
  11. Carvers Gap

    Winter 2018-2019 Observations

    A good and maybe seemingly unlikely resource might be to look at local fishing reports for the Watauga or South Holston tailwaters. They might note if either dam is spilling water. South Holston River Flyshop has a good archive. I read a few from last year and didn't note anything unusual, but sometimes those places won't say anything as they are just not on the water.
  12. Carvers Gap

    Winter 2018-2019 Observations

    I think their spillways were utilized within the last 2-3 years. Whichever year, the lakes(Watauga and S. Holston) filled up early and they had no room to store more water...so they dumped it. It is not to uncommon I don't think(maybe a few times during a decade) South Holston dumps into the spillway sluice on one side of the dam. I could be wrong though. Usually a little yellow box appears on the app for a certain dam and notes that such-and-such dam will be spilling until further notice w very high cfs numbers. For example, right now Fort Loudon is spilling until further notice(could be that the generators are offline, but more likely they are dumping water as it is not a lake that really drops during winter). I watch the generation schedules fairly regularly so I know when I can fish. It is a "no go" when they are dumping water at those rates. The rivers are basically blown out. TVA has a great lake levels app. Usually, it is not overly noticeable downstream when they open the gates. The water will appear high, but they are super careful not to exceed certain cfs limits(not sure of the actual term) which will get into residences or overrun industrial intakes. When they are sluicing(spilling) a little yellow box appears at the top. Right now, for example, it appears that South Holston and Watauga are filling their reservoirs and holding back water. It says they are sluicing right now at just about 200 cfs, but that is not true flood water being dumped. When they are dumping water, it is more like 3,000-4,000 cfs or more on the upstream dams. Fort Loudon is way more than that - 42,000 cfs roughly today. The upstream dams are likely holding back water right now(as evidenced by Ft Loudon sluicing) which means the influx from feeder streams is pretty high due to rainfall OR they are both working on generators OR they are making sure not to send too much downstream as they try to clear as much water from the downstream system as possible - probably a combo of scenario 1 and 3. And of course, all of that water is money in the bank for summer generation. As a fishermen, I like when TVA is working on a generator...usually means consistent flows of 200-300 cfs out of the SoHo. An interesting aside, South Holston actually has a third emergency spillway that empties into the woods. That one I don't think has ever been used.
  13. Carvers Gap

    February 2019 Winter Speculation

    You know that is trouble when the rainfall map (in inches) would also make a great snowfall map without being adjusted for ratios. Whew.
  14. Carvers Gap

    Winter 2018-2019 Observations

    Great info. Boone/Patrick Henry is a similar setup to Watauga/Wilbur. One dam's reservoir backs into the other dam's tailwater. I think the Wilbur and FPH are basically hydroelectric with very little additional storage as those reservoirs remain basically filled year-round. The generations schedules of those tandems are often similar. (I alway check the schedule before going out fishing on Watauga or S. Holston....the water comes up fast) Watauga, S Holston, and Boone are more flood control. Obviously, Boone is out of commission right now a they augment the earthen area of the dam. Cherokee is a huge catch basin when compared to the other two. Interesting to know the system up here was built to withstand that big of a tropical event. In those days engineers always built excellent redundancy into their systems. At this time of year, there should be plenty of storage. Where things get sketchy is if those fill early and the El Nino pattern continues. I would suspect TVA is sending plenty of water down stream right now so as to leave room for additional storage due to the current pattern - hence the Ohio River concerns. MBY concern with flooding is more in line with feeder rivers and streams...such as in our area like Reedy and Horse Creeks or in the mountains along the many creek/small river systems(North Fork here in town or Little River in Townsend as examples) that will potentially see significant precip in the coming weeks. I know some local school systems have been operating on delays so that the sun can come up and give bus drivers better visibility to see low/flood prone areas. Of note, I have one little island that I keep an eye on just upstream of Netherland Inn(you might now it...about 20 yards below the RF bridge)....during low water years it barely goes under water and even has weeds/grasses growing on it, even during spring. A couple of years ago, someone even stuck a metal chair on it. That chair was there for months on end. I don't think I have seen that island for a few months. A lot of water is being moved this winter. As an aside....you mentioned flood plains. Do you remember when FPH was testing their flood gates and a log became jammed in one of the gates and it wouldn't shut? That was an eye opener for everyone downstream. I bet some folks were sweating bullets.
  15. Carvers Gap

    February 2019 Winter Speculation

    Some really good stuff in this winter re-analysis by @Isotherm. It contains in-depth discussion on the QBO, AAM, tropical forcing, SSW, etc. Normally I would grab a quote or two in order to preface the write-up, but I think the entire piece is worth a read. Great information on this winter's drivers.
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