Update_7:00 AM_Thursday_13 February 2020
Headwater Creeks Will Continue Rising This Morning Into Mid-Day Thursday. Please Be Careful Around Swift Water, And Watch For Ponding Along Roads.
ALERT For Heavy Rain Developing Late Wednesday Into Thursday Morning
Due to recent flooding, and saturated soils, residents will need to remain alert for the potential of rapid water level rises as well as mud-rock slides. In addition, a gush of strong winds along the passing cold front will pose a tree damage danger (especially over super-saturated soils).
The downpour potential will be greater with this system than during Monday-Tuesday, raising concern for rapid water level rises. The ground is so saturated presently that a single downpour of significant intensity or duration could trigger flash flooding.
Updated_6:30 AM_12 February 2020
A surprising omission of Wise County (and Scott County) from the Flash Flood Watch by the MRX NWSFO is difficult to understand, so I reference them to their own research:
Precipitation And Flash Flood Climatology
What county during that study period had the most flash floods, the most flash flood deaths, and the only event to cost more than half a million dollars in damages within southwestern Virginia? Wise County!
Most recently, and most important to this current event, what county in southwestern Virginia has stations which have received around 9.00″ of total precipitation so far during the month of February? Wise County!
Wise, Scott, and Lee counties are all impacted by run-off from the High Knob Massif-Black Mountain corridor, the wettest long-term corridor in both Virginia and Kentucky.
Rainfall totals during Monday-Tuesday reached 1.42″ in Clintwood (6.58″ February) and 1.63″ at Big Cherry Lake Dam (8.86″ February) of the High Knob Massif. Streams are running swift and the ground is supersaturated, with areas of standing water common across the area.
ALERT For Strong SSE-SW Winds Developing Wednesday Afternoon Into The Overnight Hours Of Thursday AM
Strong SW winds will develop at upper elevations Wednesday afternoon, with downward mixing into middle elevations late Wednesday into the overnight hours of Thursday. Winds gusts of 50-60+ mph will be possible at upper elevations, with 30-50+ mph gusts at middle elevations and locally in the lower elevations.
Former Alerts And Statements
ALERT For Strong SSW-SW Winds At Middle-Upper Elevations Tonight Into Monday And Also Lower Elevations Of Northern Wise & Dickenson Counties
Strong SSW-SW winds will develop tonight into Monday as the pressure gradient strengthens in advance of the next waves of heavy rainfall. Wind gusts of 40-60+ mph will become likely along higher mountain ridges.
Strong gusts will also develop within wake zones of the High Knob Massif and Black Mountain corridor, into lower elevations of northern Wise and Dickenson counties, with breaking mountain waves.
Update_5:00 AM_A temperature jump from 31 to 45 degrees recently occurred at the official NWS station in Clintwood as strong wind gusts are mixing out the nocturnal valley temperature inversion on this Monday morning.
Recent Weather And Future Trend
Graupel has been observed with snow bursts Friday, indicating that they have a convective nature amid upward vertical motion in bitter air aloft.
The High Chaparral-Robinson Knob communities were in the core of heaviest rains with this recent flooding event, with 7.51″ of total rainfall (not including this snow)*.
*The only good news for them, water mostly runs downhill from there. Norton-Tacoma-Coeburn corridor flooding on the Wise County side, and Clinch River Valley flooding on the Scott County side, was unfortunately enhanced.
My snowfall forecast below includes the Saturday system. Amounts have already verified in many locations and it is possible that local totals could exceed what is predicted. As of 5:00 PM total snowfall had reached 1.7″ in Clintwood, with 3″ to 5″+ at upper elevations in the High Knob Massif.
Snowfall Forecast
(Friday-Saturday)
1″ to 4″ below 3000 feet
4″ to 8″ above 3000 feet
Target snowfall of 3.0″ (+/-) 1″ error potential for Norton-Wise, suggesting that 2″ to 4″ of snow will be possible. Greatest depths are expected on elevated surfaces and grass in the lower-middle elevations. Large snow depth variations are expected with blowing and local drifting at upper elevations.
In Wake Of Flooding
Extreme caution is advised around all streams as high velocity flows continue. While headwater creeks are dropping, main-stem rivers will remain elevated.
Reference my 013020 Forecast for stream links and a look at the Big Picture of this current turbulent weather pattern.
Southwestern Virginia Month-to-Date
Precipitation Totals
(1-9 February 2020)
*Robinson Knob: 7.83″
*Eagle Knob: 7.34″
*Big Cherry Lake Dam: 7.23″
Black Mountain Mesonet: 6.68″
Jonesville 3.1 WSW: 5.60″
City of Norton Water Plant: 5.47″
Clintwood 1 W: 5.16″
Saltville 1 N: 4.89″
Gate City 6.2 NNE: 4.79″
Tazewell 2.9 WNW: 4.69″
Lebanon 3.1 NNE: 4.44″
Abingdon 3 S: 4.41″
Nora 4 SSE: 4.33″
Richlands: 4.22″
Burkes Garden: 4.13″
Lebanon: 4.06″
Grundy: 3.96″
Wytheville: 3.61″
Blacksburg: 3.46″
Bluefield (WV): 3.08″
Roanoke: 2.63″
*Upper elevation locations in the High Knob Massif. Reference Mid-Winter 2020_High Knob Massif for a listing of monthly totals from Big Cherry Lake Dam.
I have not had time to even begin to go through the 1500+ photographs submitted to Chimein on WCYB’s weather page.
I selected a few amazing scenes from this flood event.
Little Stony Creek drains 16.4 square miles and heads near the High Chaparral-Robinson Knob communities of the High Knob Massif, where rainfall totals exceeded 7.00″ .
Water gushing out of the High Knob high country, and from the northeastern end of Black Mountain (Indian Mountain) caused flooding from Norton-Ramsey to Tacoma-Coeburn.
Impressive flooding along the North Fork of Clinch River which heads along the Wise-Lee county border in the High Knob Massif.
Big Stony Creek is often highlighted on this website, as a guide to steep creeks draining the high country, with Stock Creek heading in the high country southwest of Thunderstruck Knob of Powell Mountain (infamous for it’s carving of the great Natural Tunnel).
Although Big Cherry Dam holds back a huge amount of water, not including beaver dams upstream in high wetland valleys, rainfall was so heavy that the spillway overflow reached around 18″ .
While North Fork of Pound Reservoir is an unbelievable blessing to Pound, other streams such as Indian Creek and Bold Camp go into flood during these big events.
Not like 1957 and 1977, but close enough to bring back those horrid memories for residents around Haysi and Sandlick.
Terrible News For Saturated Landscape
If anyone doubts this, then merely review the Big Picture section I posted on 30 January at the link above. I knew then, based upon the combined composites of February 2018 and February 2019, that last week was going to be trouble and there is, unfortunately, no reason to doubt that this week will bring more of the same.
The really scary and frustrating aspect for myself, is that the 51-member ensemble MEAN of the European Model group has come into an even more dangerous alignment for next week, featuring a pattern that is repetitive with one wave after another of mostly rain. I expected this, as noted by what I wrote on 30 January, but at that time the period toward mid-February was showing some changes. That is no longer the case, with blocking high pressure now predicted to remain anchored over the eastern Pacific Ocean (just off the coast of North America).
Observe how similar the predicted 5-10 day anomalies (above) are to the composite mean of February 2018 + February 2019 (below). Rather amazing.
A setting like shown above is conducive to both Pacific Ocean and Gulf of Mexico moisture transport into the region next week, just like last week, with a positively tilted trough in a ridge-trough-ridge pattern.
Forecasters should remember that, like in February 2018 and February 2019, and most recently, of course, last week, a positively tilted 500 MB upper trough with westerly flow components tends to favor locations along and west of the Appalachians for heaviest rainfall amounts. The present negative tilt did not develop until after the bulk of heavy rainfall had shifted east into the Piedmont with rain changing to snow in the mountains on 7 February.
The flooding threat typically tends to be greatest along and west of the Cumberland Front, Cumberland Plateau, and Tennessee Valley with positively tilted troughs versus along the Blue Ridge with negatively tilted troughs.
Development of a negative tilt to the upper air (500-250 MB levels) trough this week was a little late to maximize rainfall along the Blue Ridge, and pre-flood forecasts that focused on the Blue Ridge were in error due to moisture and upslope forcing that were only partially in sync. Rainfall amounts were substantial along the Blue Ridge, especially within SW North Carolina where both westerly and easterly component flows are maximized, but notably less farther northeast along the mountain chain.
Despite cold air and snow at the moment, the pattern becomes unseasonably warm and moist once again next week to add support for more heavy-excessive rainfall.
The first wave producing significant rainfall Monday into early Tuesday (10-11 February) will also have snow melt from upper elevations to increase run-off into streams.
This will be followed by more worrisome waves during the middle to end of next week.
The Bottom Line: Heavy to excessive rainfall is expected next week, with the potential for serious, life-threatening flooding. Although it remains too soon to know exactly what locations will be impacted, the pattern will again favor locations along and west of the Appalachians.
Note: I had to begin the process of evacuating my house on 6 February. I was lucky and water ended up not entering the house, but I understand from personal experiences like this how scary it is for many folks who live near mountain streams. It is heart-breaking for those who must suffer through flooding, and beyond imagination for those losing loved ones to flooding. Personal property can be repaired or replaced. Precious lives can not.