Sunday, November 14, 2021

Late Autumn 2021_High Knob Massif Area


 8 November 2021
The Towers Formation
Late Autumn In Breaks Interstate Park
Wayne Browning Photograph © All Rights Reserved

The Towers are a dramatic, majestically rugged rock formation in Breaks Interstate Park and have formed in 
a great meander of the Russell Fork of Big Sandy River.

This was an excellent and long color-season, with nice color developing in the high country during mid-late September and extending now into early November
at lower elevations.

8 November 2021
Russell Fork of Big Sandy River
Late Autumn In Breaks Interstate Park
Wayne Browning Photograph © All Rights Reserved

This was one of the latest peak color seasons on record, and somewhat analogous to Autumn 2007 which has been the latest within recent decades.  

8 November 2021
Russell Fork of Big Sandy River
Late Autumn In Breaks Interstate Park
Wayne Browning Photograph © All Rights Reserved

Autumn 2007 found colors peaking at mid-upper elevations across the High Knob Massif during 18-31 October, with some color lingering at lower elevations into the Thanksgiving Holiday period.

8 November 2021
Russell Fork of Big Sandy River
Late Autumn In Breaks Interstate Park
Wayne Browning Photograph © All Rights Reserved


Precipitation Update

High Knob Massif
(Upper Elevations)

(Totals Listed By AM Measurement Format)
Monthly Total Precipitation
Big Cherry Lake Dam
(Elevation 3139 feet)

2019

January
6.14"

February
12.50"

Winter 2018-19
(1 Dec-29 Feb)
26.56"

March
5.93"

April
6.64"

May
6.75"

Spring 2019
(1 Mar-31 May)
19.32"

June
10.68"

July
10.77"

August
4.15"

Summer 2019
(1 Jun-31 Aug)
25.60"

September
0.63"

October
5.01"
( 5.89" to Midnight 31st )

November
5.20"
( 7.04" to Midnight 30th )

Autumn 2019
(1 Sep-31 Oct)
10.84"

December
8.52"

2019 Total: 82.92" (M)
 (January 1 to December 31 Period)

2020

*January
7.15"

**February
13.01"

Winter 2019-20
(1 Dec-29 Feb)
28.68"

March
9.55"
( 10.77" to Midnight 31st )

April
11.59"

May
8.73"
(6.90" on Eagle Knob of High Knob Massif)

Spring 2020
(1 Mar-31 May)
29.87"

June
7.48"

July
9.72"
(10.48" to Midnight 31st)

August
8.12"

Summer 2020
(1 Jun-31 Aug)
25.32"

September
6.21"

October 
7.06"

November 
1.96"
(Eagle Knob Snowfall: 0.5")

Autumn 2020
(1 Sep-31 Oct)
15.23"

December 
6.22"
(Eagle Knob Snowfall: 34.0")

2020 Total: 96.80" (M)
 (January 1 to December 31 Period)

2021

January
6.35"
***(Eagle Knob Snowfall: 34.0")

February
7.42"
(Eagle Knob Snowfall: 19.5")

Winter 2020-21
(1 Dec to 28 Feb)
19.99"
(21.70" on Eagle Knob)

March
10.82"
(11.14" to Midnight 31st)

April
2.53"
(Eagle Knob Snowfall: 2.5")

May
4.54"
(Eagle Knob Snowfall: Trace)

Spring 2021
(1 Mar-31 May)
17.89"

June
4.79"

July
5.55"

August
10.39"

Summer 2021
(1 June-31 August)
20.73"

September
5.82"

October
3.80"

November
2.23"
(Eagle Knob Snowfall: 1.5")

Autumn 2021
(1 Sep-30 Nov)
11.85"

2021 Total: 64.23"
 (January 1 to November 30 Period)

November 2019-October 2020: 102.34"

Autumn 2018 to Summer 2019: 91.21"

Autumn 2019 to Summer 2020: 94.44"

Autumn 2020 to Summer 2021: 73.84"

(M): Some missing moisture in undercatch and frozen precipitation, with partial corrections applied for the 24.4 meter (80 feet) tall dam structure where rain gauges are located.  Corrections are based upon 86-months of direct comparisons between NWS and IFLOWS at Big Cherry Dam (including occasional snow core-water content data).


Winter Season 2021-22
First Accumulating Snow

The first accumulating snow was observed at middle to upper elevations in locations along and northward of the High Knob Massif into morning 
hours of 13 November.

Rain and snow mixed, with little to no accumulation, was observed at elevations below 2000 feet across Wise and Dickenson counties.

Wayne & Genevie Riner measured 0.4" on Long Ridge of Sandy Ridge (at 2650 feet above sea level), with similar amounts reported across the plateau surrounding Wise and the City of Norton.

A general 1.0" to 1.5" fell at upper elevations, 
above 3000 feet, in the High Knob Massif where some snow lingered on northern slopes and crests through the weekend of 13-14 November.

24 November 2021
High Knob Massif
Looking Across High Knob Lake Basin
Wayne Browning Photograph © All Rights Reserved

The month of November 2021 has been colder 
and much drier than average across the southern Appalachians and eastern USA.

As of 0700 hours on 30 November 2021
Month-to-Date Averaged Temperature

Colder than average November conditions were observed across the eastern USA and Alaska 
during November 2021.

As of 0700 hours on 30 November 2021
Month-to-Date Averaged Temperature

Much of the nation experienced below to much below average precipitation during November.

As of 0700 hours on 30 November 2021
November 2021 Precipitation Anomaly

Annually wettest areas experienced the largest Autumn precipitation deficits during 2021.


This was a precipitation trend echoed along the expanse of the southern-central Appalachians (the mountains) during September-November 2021.

A less active Autumn 2021 pattern = less opportunities for orographic precipitation enhancement and a total reduction in orographic forcing (especially during the month of November).


This included much below average snowfall, especially across the southern Appalachians 
(near average snowfall at upper elevations in 
the central Appalachians).

24 November 2021
Sunset in High Knob Massif
Looking Across High Knob Lake Basin
Wayne Browning Photograph © All Rights Reserved

While thin ice had formed on portions of High Knob Lake as of 24 November, and especially in colder sections of Big Cherry Basin, there was no snow present across these upper elevations (only rime into morning hours of 26 November).


Winter 2021-22 
Model Projections

North American Multi-Model Ensemble
December-February Temperature Forecast

There is overwhelming model support for mild conditions across most of the USA, with exception of the Pacific Northwest, during the Meteorological Winter period of December 2021 through February 2022 (ensemble forecast above).

Individual model forecasts
are shown below for DJF
from the USA and Canada.



The CFSv2 (above) is the coldest in our region. 
 




The NCAR model (below) 
is warmest in our region.


European-MET-NCEP-JMA
Multi-System Mean Forecast

Individual contributions to the European
Multi-System Seasonal Forecast are below.








With such overwhelming agreement, it would appear that a mild winter is a slam dunk, however, it is not that simple.

As outlined by Cohen et al. (2020), models tend 
to over-estimate winter-time warmth across middle latitudes of the Northern Hemisphere.

This is at least partly due to what might be called 
a "left-brain" built in bias that essentially blinds them to cold air at extended ranges (the bias being related to global warming).


The official NOAA-CPC winter 2021-22 outlook generally follows the mean model trend, with a heavy La Nina influence.


Although November 2021 was much drier than average (as noted previously), a trend toward above average precipitation is expected to develop during winter (some of this will, of course, be snow).

Typical La Nina Pattern - North America

While the above outlines the expected pattern based on past La Nina's, there is large natural variability during any given winter.  Sudden changes from mild to colder-than-average are normal, with extreme changes often associated with changes in the Polar Vortex (PV).

View in 1080p HD for best resolution

Currently, the PV is strong and it is expected to remain strong into the near future.  A strong PV favors milder-than-average winter conditions across the middle latitude continents.


At this time last winter (blue line above), the 
PV was being disturbed and began weakening.


Winds are stronger than average (below) 
as expected when the PV is also strong.


This does not mean that cold air and snow can not occur, with the 6-10 December period (next week) being of upcoming interest, but prolonged wintry conditions are not as likely while the PV remains strong. 

This section is under construction.  Please check back.