Thursday, March 1, 2018

February 2018 - Wettest On Record In Virginia


February 28, 2018
High Knob Massif
Whitewater In South Fork Gorge
Photograph by Wayne Browning - © All Rights Reserved

February 2018 generated the greatest precipitation amounts ever measured in the state of Virginia, with maximum totals of 14.00" to 15.00" in the high country of the High Knob Massif.


A total of 12.86" was hand-measured by superintendent Gary Hampton and his staff at 
the Big Stone Gap Water Plant, near the mouth 
of South Fork Gorge, during February to top the previous valley record established by the Big Stone Gap Wastewater Treatment Plant in 2003.

*The 11.81" measured by the Big Stone Gap WWTP during 2003 established a new record for February wetness in the state of Virginia ( a general 12.00" to 13.00" fell in the high country of the High Knob Massif in February 2003.

February 28, 2018
High Knob Massif
Whitewater In South Fork Gorge
Photograph by Wayne Browning - © All Rights Reserved

February 2018
Daily Precipitation Totals
Big Stone Gap Water Plant

2/2:  0.71

2/4:  0.31
2/5:  0.56

2/7:  1.02
2/8:  0.31

2/10: 0.79
2/11: 4.38
2/12: 0.62

2/14: 0.26
2/15: 0.29
2/16: 0.55
2/17: 0.12
2/18: 1.41
2/19: 0.03

2/21: 0.04
2/22: 0.04

2/24: 0.02
2/25: 1.06
2/26: 0.25
2/27: 0.09
2/28:    T

Total: 12.86"

Totals were even greater up above across the high country, with 14.37" at Big Cherry Lake Dam of the High Knob Massif ( * ).

*Although snow core data was used to help make this total more accurate, it likely remains too low given significant wind induced rain gauge undercatches as air flows across 
the highly elevated Dam.

High Country of High Knob Massif
Graphic by Wayne Browning - © All Rights Reserved

Big Cherry Lake has a water elevation of 3120 feet, with higher elevations toward the basin head often being wetter than Big Cherry Dam.

Big Cherry Dam of High Knob Massif
Meteorological Winter Precipitation Totals

December 2017
3.88"

January 2018
5.48"

February 2018
14.37"

Total: 23.73"

Around 40.0" of snow fell in the meteorological winter period across the head of Big Cherry Lake basin, MUCH below average for the second consecutive winter.

Approximately 53% of days had 1" or more of snow depth on northern exposed slopes, with mean depths peaking around 10" during the three month meteorological winter period.  


More complete winter temperature data
will be presented in coming weeks.

Meteorological Winter Temperatures
December 1, 2017 to February 28, 2018

Big Cherry Valley 2
( Elevation 3248 Feet )

Average Daily MAX: 40.0 degrees
Average Daily MIN: 22.2 degrees
Winter MEAN: 31.1 degrees
Maximum Temperature: 69 degrees
*Minimum Temperature: -7 degrees

*Min temperatures as cold as -10 degrees below zero were recorded
in the valley.  Locally colder temperatures likely occurred.  Mildness
in mid-late February skewed the winter season warmer than average.


A huge contrast in precipitation amounts has been observed across southwestern Virginia, and the Old Dominion, during this winter season.



Amazingly, a large portion of Virginia is currently experiencing abnormally dry to drought conditions.

Courtesy of NC Climatology Office

Observe that totals decrease both UP-basin along the Clinch River and eastward across southwestern Virginia.  A trend that shows up well in longer-term climatology during the orographic forcing season.

The Orographic Forcing Season is November-April, with May and October often being months of transitions between the Orographic and Convective seasons.

Spring 2018 Flood Outlook

Richlands recorded the most February precip in locations upstream of the High Knob Massif, within the Blacksburg NWS Forecast Office coverage area of the Clinch River Basin, with 7.63" .

A total of 8.48" was measured in the Town of Lebanon, but it is 
within the Morristown, Tn., NWS Forecast Office coverage area.

Courtesy of the Blacksburg NWSFO

Although these are truly amazing differences, they are analogous to many other periods documented during past decades.

Courtesy of the Wakefield NWSFO

General 12.00" to 18.00" less precipitation since the beginning of meteorological winter between 
Big Cherry Dam and places to the east in Virginia.

Courtesy of the Baltimore-DC NWSFO

Meadows of Dan 5 SW, along the Blue Ridge escarpment, is typically one of the wetter locations in Virginia, but had 12.82" less precipitation during Meteorological Winter than Big Cherry Dam. 

Courtesy of NC Climatology Office


Wintry Transition In March 2018

High Knob Massif Crestline
Lingering Snow Drifts On March 16
Photograph by Wayne Browning - © All Rights Reserved

Although only a fraction of their original size, drifts remained notable along wind swept crest lines a couple 
days after this latest winter storm event ( one of a series 
of wintry systems to impact the high country in March ).

Large snow drifts lingered along high crest lines around High Knob in wake of the winter storm event of March 12-14, which dropped a foot or more of snow in the high country.

Reference Superstorm Of March 1993 in this section for a look back at a monster winter storm during this same time period 25 years ago.

March 16, 2018
Big Cherry Lake
Coltsfoot ( Tussilago farfara )
Photograph by Wayne Browning - © All Rights Reserved

This is the time of year in which interesting contrasts occur over relatively short distances, with a bounty of Coltsfoot wildflowers blooming around Big Cherry Lake amid scattered patches of melting snow ( Coltsfoot is an introduced species and is often among the first signs of spring ).

High Knob Massif Crestline
Lingering Snow Drifts On March 16
Photograph by Wayne Browning - © All Rights Reserved

Yellow Trout Lily ( Erythronium americanum
is a native wildflower and is now at peak bloom in lower elevations, adjacent to the High Knob Massif ( these lilies will begin to bloom a little later at upper elevations in the massif ). 

March 17, 2018
Lower Elevations of Cumberland Mountains
Yellow Trout Lily ( Erythronium americanum )
Photograph by Wayne Browning - © All Rights Reserved

Reference Beginning Of Spring 2017 for a review 
of conditions that featured a peak in Trout Lily blooms around and after March 21 at the lower elevations ( the lower elevation peak was around March 18 during 2016 ).

As noted last year, and observed already this year, 
these native flowers are typically covered in snow 
one to numerous times during their growing season.

March 16, 2018
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

Big Cherry Dam of High Knob Massif
 Precipitation Update ( January 1-March 16 )

January 2018
5.48"

February 2018
14.37"

March 1-16, 2018
2.42"

Total: 22.27"

March 16, 2018
Low Dewpoint Air In High Country
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

Low dewpoint air in the high country during March 16 allowed for rapid evening temperature plunges in high valleys prior to increasing overnight clouds and the first strong thunderstorms of the season by late on March 17.

March 16, 2018
Low Dewpoint Air In High Country
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

Flipping through some days featured by the webcam at the University Of Virginia's College At Wise reveals the changing conditions observed during this first half of March in 2018.


Daily Weather Review
High Knob Massif Webcam
( Changing Conditions Of March 1-16 )

March 1 at 11:41 AM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 2 at 5:55 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 3 at 3:35 AM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 4 at 5:42 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 5 at 2:28 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 6 at 6:34 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 7 at 8:45 AM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 8 at 12:49 PM
Intense Snow Squalls
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 9 at 8:29 AM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 10 at 4:30 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 11 at 4:28 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 12 at 3:16 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 13 at 8:20 PM
Blinding - Convective - Snow Squalls
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 14 at 8:41 AM
Intense Snow Within A Snowstreak
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 15 at 3:53 PM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department

March 16 at 10:25 AM
University Of Virginia's College At Wise
Courtesy of Computer Science-Mathematics Department


Weather Event Highlights
( March 1-16, 2018 )

The month of March is notorious for wild weather extremes in the mountains, and this month has not disappointed weather observers.

March 2, 2018 at 7:01 AM
High Chaparral of High Knob Massif
Photograph by Darlene Fields - © All Rights Reserved

Although not showing up in the daily review from UVA-Wise, up to 1" or locally more of snow made roads slick at upper elevations in the High Knob Massif into morning hours of March 2.

March 2, 2018 at 7:12 AM
State Route 706 In High Knob Massif
Photograph by Darlene Fields - © All Rights Reserved

The next weather event that produced snow into early hours of March 7 generated the first intense snow squalls during March 8, with up to 3" or 
more of local accumulation.

March 7 at 6:13 AM
Heavy Snow In High Chaparral Community
Photograph by Darlene Fields - © All Rights Reserved

Wayne & Genevie Riner Thoughts:

Cows in the Spring Snow 
Even with the warmer weather and then the recent snow, the cows need to be fed.  The cow on the right has recently given birth to a new calf.

March 7 at 8:17 AM
Long Ridge of Tennessee Valley Divide
Photograph by Genevie Riner - © All Rights Reserved

Spring is a time for rebirth and renewal 
as the battle between seasons begins!

March 14, 2018
City of Norton
Half A Foot Of Snow
Photograph by Jimmy Fawbush - © All Rights Reserved

The most intense weather of early-mid March 2018 developed during the winter storm of March 12-14 when intense, locally convective snow squalls generated whiteout conditions.

March 13, 2018
Bitterly Cold Air Aloft Signature In Clouds

I began out-looking this setting as early as March 11 on the Appalachian Climate Centermore than 48-hours in advance of whiteout producing snow squalls.  Development of intense squalls became certain upon looking at March 13 visible imagery.

March 13, 2018
Bitterly Cold Air Aloft Signature In Clouds

Snowstreaks formed in the NW flow 
field into morning hours of March 14.

Snowstreaks on GOES-16 Visible Imagery

March 14, 2018 at 9:52 AM
High Chaparral of High Knob Massif
Photograph by Darlene Fields - © All Rights Reserved

A total of 10.0" of snow fell in the High Chaparral community of the High Knob high country between 7:00 PM March 13 and 1:00 PM on March 14.

*A total of 12.5" fell during the March 12-14 period, with locally higher amounts in the high country, along with 
large drifts of 2-3+ feet.

March 14, 2018
High Chaparral Community of High Knob Massif
Photograph by Darlene Fields - © All Rights Reserved

Although melting rapidly, this event generated the deepest snow depths of the season to date ( topping the general 8-12"+ of early February 2018 ).

March 15, 2018

Clouds remained over about half of the High Knob Massif at the time of this MODIS image on March 15 ( above ), with the high country surrounding Big Cherry Lake southwest to above the Duffield Valley being highlighted by snow cover.

The top of Cumberland Gap National Historical Park is covered by snow toward the southwest, with a narrow strip of snow cover also seen along the crest of the Great Smoky Mountains National Park to the south.

This section is under construction.  Please check back