Tuesday, April 17, 2018

Explosive Spring Rebirth Period Delayed


April 16, 2018
Robinette Branch of Powell River
Mid-April Snowfall In High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

The famed 30-day period of most explosive spring renewal has now arrived, with a blanket of snow! 

*The April 15 to May 15 period is climatologically the interval which generates the most dramatic landscape changes as winter gives way
to spring rebirth.  Only upper elevations, above 3000 feet, within the High Knob Massif require longer ( often to early June ) to complete
the transition to full summer conditions.

A huge temperature plunge during April 16 brought snow, strong winds and bitterly cold wind chills to the high country, with several inches accumulating at highest elevations in the High Knob Massif.

April 16, 2018
Northern Base of High Knob Massif
Legion Park - City of Norton Parks & Recreation
Photograph by Wayne Browning - © All Rights Reserved

Snow was heavy enough to make roads slick down to below the 3000 foot level by the early evening hours of April 16.

April 16, 2018 at 6:18 PM
Pouring Snow At 3200 Feet Elevation
Flag Rock Recreation Area-State Route 619
Photograph by Wayne Browning - © All Rights Reserved

Although State Route 619 was already snow covered at highest elevations prior to 5:00 PM on April 16, the sticking snow level really dropped with heavy snow showers and squalls that developed prior to sunset ( with low visibility at times ).

April 16, 2018
Water Elevation 3318 Feet
Falling & Blowing At Upper Norton Reservoir
Photograph by Wayne Browning - © All Rights Reserved

April 16 at 5:21 PM
Snow Showers & Snow Squalls
Upper Norton Reservoir of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

April 16 at 5:36 PM
Pouring Snow At Upper Norton Reservoir
Photograph by Wayne Browning - © All Rights Reserved

April 16, 2018
Heavy Snow Changes Perspective In Forest
Photograph by Wayne Browning - © All Rights Reserved

April 16, 2018
Northern Base of High Knob Massif
Whitewater & Snow Decorate Legion Park
Photograph by Wayne Browning - © All Rights Reserved

April 16, 2018
Northern Base of High Knob Massif
Whitewater & Snow Decorate Legion Park
Photograph by Wayne Browning - © All Rights Reserved

April 16, 2018
Northern Base of High Knob Massif
Whitewater & Snow Decorate Legion Park
Photograph by Wayne Browning - © All Rights Reserved

A short video from the Computer Science-Mathematics building at UVA-Wise highlights these late afternoon-early evening snow showers and squalls; although, most of the daylight hours featured these conditions ( especially at upper elevations in the High Knob Massif which is 
rarely visible from Wise ).

High Knob Massif Webcam
University Of Virginia's College At Wise

April 16, 2018
Snow Showers & Snow Squalls

Courtesy Of Computer Science-Mathematics Department

April 16, 2018
Legion Park of City of Norton
Northern Base of High Knob Massif
Great Rhododendron ( Rhododendron maximum )
Photograph by Wayne Browning - © All Rights Reserved

April 16, 2018
Northern Base of High Knob Massif
Majestic Cove At Legion Park In Norton
Photograph by Wayne Browning - © All Rights Reserved


Spring Slowly Arriving

April 21, 2018
Looking Across High Knob Lake Basin
Photograph by Wayne Browning - © All Rights Reserved

Maple trees are beginning to bud in the high country as a few spring ephemeral wildflowers emerge upon the open forest floor during what 
has been a chilly April in 2018.

Chilly April In High Country

The first 21 days of April featured numerous spells with temperatures dropping into the 10s to lower 20s within the high country of the High Knob Massif.  This included up to 9.0 inches of total snowfall at highest elevations.

March 1 to April 21, 2018
500 MB Geopotential Height Anomalies

This has been part of an anomalously 
cold meteorological spring season.

March 1 to April 21, 2018
925 MB Air Temperature Anomalies

March 2018 Temperatures
Eagle Knob of High Knob Massif

 Average Daily MAX: 40.8 degrees
Average Daily MIN: 25.3 degrees
MEAN: 33.0 degrees
MAX Temperature; 67 degrees
MIN Temperature: 11 degrees
Total Snowfall: 28.0"

*March was nearly as cold on Eagle Knob as
January 2018 was in the Tri-Cities, Tennessee,
with 4 times as much snow as observed during
the entire winter season at TRI.

April 14, 2018
Big Cherry Wetland Valley
Dwarf Mountain Anemone
( Anemone quinquefolia var. minima )
Photograph by Wayne Browning - © All Rights Reserved

Canada Mayflowers ( Maianthemum canadense ) were emerging across many acres on April 21; however, not a single flower was yet found to be blooming.  Dwarf Anemone and Halberd-leaved Violets are the most numerous species blooming above 3000 feet ( as of April 21 ).

*It is still early for Canada Mayflower to be blooming, 
with May typically being the month to feature blooms 
on this northern species.

April 21, 2018
Northern Hardwood Forest
Star Chickweed ( Stellaria pubera ) and
Halberd-leaved Yellow Violet ( Viola hastata )
Photograph by Wayne Browning - © All Rights Reserved

April 21, 2018
Northern Hardwood Forest
Ramp ( Allium tricoccum )
Photograph by Wayne Browning - © All Rights Reserved

April 21, 2018
Northern Hardwood Forest
Mayapple ( Podophyllum peltatum ) Emerging
Photograph by Wayne Browning - © All Rights Reserved

The coolness of Spring 2018 has species running later than in recent years, with this Pink Lady's-slipper Orchid ( below ) being in peak bloom on April 19 in 2016 and at this stage around 
April 21 during 2017.

April 26, 2018
Still Developing - Not Yet Mature
Lower Elevations of Cumberland Mountains
Pink Lady's-slipper Orchid ( Cypripedium acaule )
Photograph by Wayne Browning - © All Rights Reserved

April 27, 2018
Lower Elevations of Cumberland Mountains
Large-flowered Trillium ( Trillium grandiflorum )
Photograph by Wayne Browning - © All Rights Reserved

April 27, 2018
Wild Geranium ( Geranium spp. )
Photograph by Wayne Browning - © All Rights Reserved

April ended as an unseasonably cold month.

April 2018 Temperatures
Eagle Knob of High Knob Massif

Average Daily MAX: 51.1 degrees
Average Daily MIN: 32.2 degrees
MEAN: 41.6 degrees
MAX Temperature; 73 degrees
MIN Temperature: 16 degrees
Total Snowfall: 9.0"

 Average temperatures became colder at night on high valley floors to mark a trend that would increase through the first half of May. 

 April 2018 Temperatures
Big Cherry Wetland Valley 4

Average Daily MAX: 55.3 degrees
Average Daily MIN: 30.8 degrees
MEAN: 43.0 degrees
MAX Temperature; 76 degrees
MIN Temperature: 19 degrees

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Saturday, March 24, 2018

Turbulent Weather Pattern Of Spring 2018


March 23, 2018
High Crest Lines of High Knob Massif
Snow Drifts In Wake of March 20-22 Storm
Photograph by Wayne Browning - © All Rights Reserved

The first month of Meteorological Spring 2018 
has been turbulent, with all forms of precipitation including snow and ice storms in the high country of the High Knob Massif.

Afternoon of March 23, 2018
Kyle Hill & Kendall Morse In Snow Drifts
UVA-Wise Undergraduate Field Research
Photograph by Wayne Browning - © All Rights Reserved

Field research students Kendall Morse and Kyle Hill experienced interesting and beautiful high country conditions during March 23, as part of 
the expanding Undergraduate Research Program 
at the University Of Virginia's College At Wise.

March 23, 2018
High Knob Lake Dam
Looking Somewhat Like A Glacial Lake
Photograph by Wayne Browning - © All Rights Reserved
This included taking a snow core, surveying large snow drifts along high crest lines, as well as a hike into beautiful High Knob Lake basin where the lake was exceptionally beautiful with a wondrous aqua-green to bluish-green coloration.

March 23, 2018
Overflow At High Knob Lake Dam
Head of Mountain Fork of Big Stony Creek
Photograph by Wayne Browning - © All Rights Reserved

 While steep southern exposed slopes around the lake had only patchy snow, a general 1" to 9" of snow depth remained on the northern exposed slopes.

March 23, 2018
Upper End of High Knob Lake
High Knob Lake Recreation Area
Photograph by Wayne Browning - © All Rights Reserved

A snow core generated 0.68" of water content to suggest at least 7" fell, if not a bit more given that snow density in these upper elevations had a snow-to-water ratio somewhat greater than 10:1 . 

*Most of the snow fell with air temperatures in the 10s to low-mid 20s.

March 23, 2018
Remote Section Of High Knob Lake
Photograph by Wayne Browning - © All Rights Reserved

Only part of the March 20-22 storm was snow, with a total water equivalent of around 2.00" or more in these upper elevations ( 1.28" measured at the base in the City of Norton ).

 This continued a very wet pattern that had the 2018 precip tally up to approximately 25.00" at 
Big Cherry Lake Dam in advance of the nasty, water loaded snow-ice storm of March 24-25.

March 25, 2018
In Wake Of Ice-Snow Storm
Eagle Knob of High Knob Massif

Big Cherry Dam of High Knob Massif
 January-March Precipitation Totals

January 2018
5.48"

February 2018
14.37"

March 2018
7.09"

Total: 26.94"

A total of 30.82" of precipitation 
during the December-March period.

*The total is somewhat low due to wind induced rain gauge under-catch with air flowing across Big Cherry Dam ( rain gauges are 20 feet above the water level to the northeast and around 100 feet above ground level toward the southwest ).

March 31, 2018
Water Elevation 3120 feet
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

March 31, 2018
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

March 31, 2018
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved

Recent low temperatures in Big Cherry Lake basin dropped into the low-mid 10s during March 22 and into the low-mid 20s on March 31 ( the last 0 degree temperatures occurred in early February ).

 Another morning featuring 10s in high country valleys is upcoming into April 5.


Historic Snowstorm
April 2-5, 1987

Spring snow is common in the mountains, with historic events occasionally occurring as mT 
( maritime tropical ) and cP ( continental Polar ) 
air masses clash.

 A historic late season winter storm generated a general 2 to 4 feet of snow depth in locations along and north of the High Knob Massif during the first days of April in 1987.

Click through the charts to observe
the different isobaric levels in motion.

Reanalysis Charts
April 2, 1987 at 1200 UTC

Reanalysis Charts
April 3, 1987 at 0000 UTC

Reanalysis Charts
April 3, 1987 at 1200 UTC

Reanalysis Charts
April 4, 1987 at 0000 UTC

Reanalysis Charts
April 4, 1987 at 1200 UTC

Reanalysis Charts
April 5, 1987 at 0000 UTC

Reanalysis Charts
April 5, 1987 at 1200 UTC

Reanalysis Charts
April 6, 1987 at 0000 UTC

Reanalysis Charts
April 6, 1987 at 1200 UTC

Carl Henderson, electrical engineer for the former Blue Ridge PBS transmitter station on Eagle Knob of the High Knob Massif, reported a general 2 to 6 feet of snow depth in wake of this major event.

Total snowfall was generally significantly more than total snow depths due to settlement, melting and sublimation amid higher spring solar angles than indicated below ( the exception being much higher drifts which locally formed along mountain ridges ).

Nearly 2000 vertical feet below, Gary Hampton reported 3 feet of snow depth at the City of Norton Water Plant on the northern base of the High Knob Massif.  These were the greatest depths reported in Virginia during this event.

U.S.G.S. Digital Elevation Model

Great storm events tend to accentuate the great orographic sections of the Appalachians, with this epic April 1987 snowstorm being no exception.

Snow Depth Differentials

*High Knob Massif-Kingsport
48" - 11" = 36"

**Pickens-Millgap
42" - 10" = 32"

*A total of 14.8" officially measured at TRI in northeastern Tennessee which, like Kingsport, was downstream of the High Knob Massif & Cumberland Front during much of 
this storm event.

**Difference between Pickens, Wv., and Millgap in Highland County, Va., which was downstream of the Allegheny Front during much of this event.  A total of 32.8" of snow was measured at Snowshoe Mountain.

Bigger events in the past have generated even larger differences along storm flow trajectories, of course, with this being a nice mid-spring example.
Slow Emergence In 2018

April 1, 2018
Lower Elevations of Cumberlands
Rue Anemone ( Thalictrum thalictroides )
Photograph by Wayne Browning - © All Rights Reserved

The first Rue Anemones began blooming in lower elevations of South Fork Gorge of the Powell River by the end of February-early March, in wake of record February wetness and unseasonable mildness during mid-late month.  Numerous snowy periods and cold followed in March.

A colder, more snowy March than February in 2018 has emergence of spring ephemeral wildflowers off to a slow start, at least within locations along and north of the High Knob Massif.

April 5, 2018
Lower Elevations of Cumberlands
Bloodroot ( Sanguinaria canadensis )
Photograph by Wayne Browning - © All Rights Reserved

Big Cherry Valley 4 in the high country of the 
High Knob Massif shows the 2018 temperature trend well, with not only colder average temps during March than February but also average nightly low temperatures which have been 
colder in the first half of April than the average February minimum!

High Knob Massif
Big Cherry Valley 4 - Elevation 3186 feet
Average Temperatures January 1-April 14

Coldest Recent MINS

February 3
0 degrees

March 15
12 degrees

April 8
19 degrees

April 14, 2018
Field Research Students
Kyle Hill, Kendall Morse, Michael Hinkle
Photograph by Wayne Browning - © All Rights Reserved

University Of Virginia's College At Wise

Some signs of spring are finally beginning to emerge in the high country, with Halberd-leaved Yellow Violets ( Viola hastata ) in bloom along with the first Dwarf Anemones ( Anemone quinquefolia var. minima ).  A vast array of Canada Mayflower 
( Maianthemum canadense ) is coming up but not yet blooming.  

April 14, 2018
Big Cherry Lake Wetland Valleys
Dwarf Anemone ( Anemone quinquefolia var. minima )
Photograph by Wayne Browning - © All Rights Reserved

April 14, 2018
Beaver Dam & Pond In Big Cherry Wetlands
Photograph by Wayne Browning - © All Rights Reserved

Beaver Dams in the valleys were breached by February floods, with upcoming maintenance 
work to be done by beaver colonies into 
the summer season.

February 2018 - Wettest On Record In Virginia

April 14, 2018
Sphagnum Filled Wetlands
Photograph by Wayne Browning - © All Rights Reserved

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