May is no stranger to cold air, with the setting in 1989 similar to what is being observed currently (in 2020) when a wet and colder than average May followed a mild and much below average snowfall regime during the 1988-89 winter season.

Flash flooding became a deadly issue during early May 1989, with the following written in my weather journal during this time (1989 was a wet year):

Around 8:00 PM, 5 May 1989: A family of three were plunged into swollen Garden Creek of Levisa Fork River after the Van they were driving collided with a coal truck on State Route 624. They were quickly swept downstream into the raging Levisa Fork. All three were lost and drown. One body was recovered 5-6 miles downstream, another in Grundy, and the third victim was eventually discovered 30 miles downstream, north of Fishtrap Lake in Pike County, Kentucky. Truly, a terrible tragedy!

Flash flooding occurred along the South Fork of Powell River within the Cracker Neck to Big Stone Gap section of Wise County, the Guest River in Wise County, the South Fork of Pound River in northern Wise County, and the Russell Fork River (among others) in Dickenson County.

Additionally, numerous mud-rock slides were reported.

Heavy rain accompanied a strong southward dip in the jet stream, with a surge of unseasonably cold air that changed precipitation into snow.

The observation time was 1700 hours (5 PM) daily in Wise, such that only 1″ remained on the ground at 5 PM on 7 May 1989 (increase zoom factor of page for best chart viewing).

Snow fell heavily into morning hours of May 7:

As the midnight hour passed into 7 May a wintry mix falling in mountain valleys began changing into large, fluffy flakes of snow as air temperatures reached the freezing mark. By 4:30 AM on 7 May, moderate-heavy snow was falling across the mountain area (from the High Knob Massif northward).

Snowfall rates intensified around dawn, with the break of sunrise appearing to be a mid-winter blizzard had it not been for spring vegetation.

Snowfall totals reached 2.3″ in Clintwood, 3.3″ in Wise, and 4″ or more at upper elevations within the High Knob Massif.

*This snow was so majestic, as adhesive crystals intermingled with a spectrum of hues representative of the spring forest, that it was part of the reason I was inspired to become a nature photographer.

Clearing skies allowed the air temperature to drop below freezing in Clintwood prior to midnight on 7 May, with high humidity in wake of rain and snow resulting in significant freeze damage (especially at lower-middle elevations which had more advanced spring growth).

Visible freeze damage was observed in the following tree species (to note a few impacted):

Hickory
(Carya spp.)

American Beech
(Fagus grandifolia)

Tulip-poplar
(Liriodendron tulipifera)

Magnolia
(Magnolia spp.)

Sourwood
(Oxydendrum arboreum)

Black Locust
(Robinia pseudoacacia)

Sumac
(Rhus spp.)

Sassafras
(Sassafras albidum)

Visible freeze damage remained evident on species such as American Beech into June, although I do not recall it being as severe and impressive as the forest browning which occurred during May 2005.

Min temperatures during the 7-8 May period reached 23 degrees within Burkes Garden Basin, 26 degrees in Clintwood, 27 degrees in Canaan Valley Basin, 28 degrees in Wise, and 30 degrees in the Great Valley at TRI (tying previous records for all-time May coldness in the Tri-Cities of northeast Tennessee).

Cold air collecting basins, at upper elevations above 3000 feet, tend to be coldest on nights conducive for radiation cooling.

Refer to Focus On Research_Big Cherry Basin for more informaton.

Great Arctic Cold Wave Of Jan 1985

One of the greatest cold waves in recent decades struck with a ferocious vengeance during January 1985.

The true significance of the above sea level pressure analysis will be highlighted below, as this set the January 1985 arctic outbreak apart from more recent extreme cold events.

Anomalously warm conditions dominated December 1984, especially the second half of the month, through Christmas up to the beginning of the New Year.

A slightly positive North Atlantic Oscillation and a weakly positive Arctic Oscillation ( 0.446 index for December ) did not tell the full story during this ENSO neutral winter with its negative phased Quasi-biennial Oscillation ( QBO ).

A major mid-winter warming in the stratosphere, typically called a Sudden Stratospheric Warming ( SSW ), developed during late December 1984 with a reversal of the flow field at 60 degrees North and 10 MB into early January 1985.

The World Meteorological Organization ( WMO ) classifies a major SSW event as one which reverses the zonal mean zonal wind from westerly to easterly at 60 degrees North latitude and 10 MB.

Observations Of A Major Stratospheric Warming In Dec 1984

Although Wave 1 forcing had become significant by late November 1984, to initiate Polar Vortex perturbation, this weakened as Wave 2 forcing reached record strong levels by late December 1984.

Under favorable conditions planetary and gravity waves emanating from the troposphere penetrate into rarefied  air of the stratosphere where they break, like ocean waves rolling into a beach and feeling the frictional drag of the surface, to release their momentum and energy fluxes.

Reference Middle Atmospheric Dynamics by Andrews, Holton, Leovy., 1987 for addition information.

Temperatures high above the North Pole rapidly climbed to record warm levels by the beginning of January 1985 as this Sudden Stratospheric Warming ( SSW ) event weakened the Polar Vortex in the stratosphere.

While air temperatures fell back to below average at 10 MB above the North Pole before the end of January 1985, record warm conditions persisted lower down at 100 MB through February 1985 with stratospheric-tropospheric coupling as recently documented and highlighted by Judah Cohen.

Eurasian Snow Cover Variability and Links with Stratosphere-Troposphere
Coupling & Their Potential Use in Seasonal to Decadal Climate Predictions

Characteristics Of Stratospheric Warming Events During NH Winter also highlights stratospheric-tropospheric coupling.

While it may seem the “polar” opposite of what should be, when the Polar Vortex weakens it creates a more favorable setting for arctic air outbreaks into middle latitudes as this great swirling mass of brutal cold relaxes and no longer pulls everything zonally across the Northern Hemisphere.

As exemplified by this current 2017-18 winter, it does not take a major SSW event to impact the Polar Vortex and cause changes in middle latitude conditions.  The odds of  having a major SSW event increases during a -QBO winter (which is presently the case).

A 20-Year LiDAR Observations Of SSW Over A Mid-Latitude Site

While impacts began being felt almost immediately after this SSW event occurred, with both colder conditions and frequent periods of frozen precipitation locally, it was not until January 18-19 with approach of a major arctic front that implications of what was coming became clear.

While the magnitude of the bitter cold is off the bottom of the Kelvin scale used on these reanalysis charts, they still are useful in showing where the core of the coldest air was centered.  Right over the Mountain Empire!

Reported Minimum Temperatures
( In Degrees Fahrenheit )

-21 degrees
Clintwood 1 W

-24 degrees
Campus of UVA-Wise

-25 degrees
*Town of Clintwood

-30 degrees
**Mountain Lake Biological Station

-35 degrees
***High Chaparral Community

*Recorded by Paul D. Buchanan in the town of Clintwood at the previous official recording site for precipitation ( 1964-Jan 1988 ).

**The all-time coldest temperature officially recorded in Virginia at a designated National Weather Service Cooperative Station. The elevation was at 3984 feet with 7″ of snow depth.

***The coldest unofficial temperature reported in the High Knob Massif; although, it is likely that colder temps have occurred and will eventually be documented by the undergraduate research project ongoing at the University of Virginia’s College At Wise.  Recording instruments were not in place at the summit level during this 1985 period, when air temperatures were almost certainly colder over a substantial snowpack.

The recorded air temperature fell from 20 degrees at Clintwood 1 W at 7:00 PM on January 19 down to -15 degrees below zero by the morning to mid-morning period of January 20:

-15 degree AM MIN on January 20

-6 degree PM MAX on January 20

-10 degrees at 7:00 PM on January 20

These were lower elevation ( 1560 feet above sea level ) readings, with temperatures being much colder at upper elevations above 3000 feet in the area.

The cold was enhanced by widespread snow cover, with a snowpack at upper elevations in the High Knob Massif.

Note 1985 precipitation totals are given in the far right column, and the following local stations can be added to that list:

1985 Total Precipitation

Clintwood 
35.69″

Appalachia Lake Water Plant
43.88″

City of Norton Water Plant
49.85″ ( M )

( M ) – Indicates missing moisture in snowfall.

Precipitation data for the City of Norton has been found back to January 1983, so Norton was not recognized in 1985 as being the wettest town or city in Virginia as that fact had not yet been established back then. 

However, by comparison of totals during 1985 with Norton ( which had missing data in snowfall using a small 4″-diameter NWS style gauge ) it can be seen that only time would be required. 

While recorded MINS were impressive, this literally told only part of the story which separated this 1985 outbreak from more recent extreme cold.

Both from personal experience, and from raw data, what really made the January 1985 outbreak one of the greatest within recent decades was WIND and barbaric Wind CHILL.

This was not the type of cold experienced most recently during the month of February 2015 when the official MIN dropped to a brutal -23 F degrees below zero in Clintwood, and very likely to below -30 degrees within high valleys of the High Knob high country where snow depth was 3 to 4 feet deep!  The UVA-Wise collection of high resolution data just missed an opportunity to rewrite the known, or recorded, temperature climatology of Virginia in Feb 2015.

The brutal cold of February 2015 was biased toward the mountain valleys, where cold air drainage and radiational cooling over a deep snowpack was the driving force directly beneath High Pressure with light winds and clear skies.

The cold in January 1985, by contrast, occurred on WNW- NW upslope flow and strong winds such that clouds and upslope snow showers continued which biased the coldest conditions to upslope locations at upper elevations.  That is why the High Chaparral community, at 3300 feet, reported the lowest local temperature even through summit level readings were likely colder above 4000 feet.  Certainly, when factoring in strong winds, wind chill values were barbaric with -40 to -70+ below zero readings which are rarely ever experienced so far south in latitude.

#The old wind chill index used in the 1980s would have generated even lower chill values, with above values based upon the current wind chill index.

It should be noted that while arctic air masses are often stratified with the coldest air near the surface, in the low levels of the troposphere, that when orographic forcing is significant it can drive air upslope with adiabatic cooling occurring as air expands during forced lift ( significantly warmer air can then exist above the mountain tops, with inversional conditions ).  In this case the arctic mass was relatively deep in vertical extent; although, no doubt with some stratification due to its density.

Surface temperatures can become colder than the 850 MB air due to such a process, as it can when light winds and clear skies set up ideal cold air drainage and radiational cooling like observed most recently during the extreme cold of February 2015.  Multiple ways, especially in the mountains, to get air colder than incoming values indicate on any specific isobaric level ( e.g., 850 MB ).

Original National Weather Service Data Forms submitted by Roy L. Wells, Jr., for the official station of Wise 1 SE located on the campus of University of Virginia’s College At Wise.

The 1977-78 Winter Season

This was the second of back-to-back harsh winters in the mountains, and across most of the eastern United States, with even more snowfall and prolonged snow depth than observed during the 1976-77 Winter ( especially in upper elevations, above 3000 feet, of the High Knob Massif ).

October 1977

November 1977

The first big snowfall event of this winter was a SW Upslope Flow episode featuring 16″ of reported snow depth in Big Stone Gap and 11″ ( at 5 PM observation time ) in Wise on November 27.  This event started a LONG snow cover season in the High Knob Massif.

December 1977

January 1978

Although snow had already been covering upper elevations in the High Knob Massif for a long time ( since November 26 in places ), snowfall on January 9 marked the beginning of another long and harsh wintry period that featured 1″ or more of snow depth at my observing station in Clintwood ( elevation just 1560 feet ) during the entire interval from January 9 to March 11.

February 1978

A deep snowpack developed amid upper elevations of the High Knob Massif, with Otis & Nancy Ward measuring a mean depth of 42″ at their home in the Robinson Knob community of the massif ( elevation 3240 feet ).

*This contrasted with mean snow depths that reached 14″ at my observing station in Clintwood ( elevation 1560 feet ) where around 19 days during the winter featured double digit depths.

Steve Blankenbecler reported depths of more than 4 feet along northern slopes heading into Eagle Knob, where he said it was like “driving through a tunnel” to reach the site for Virginia-Kentucky Communications near the summit.

March 1978

April 1978

A general 73″ to 82″ of snowfall was observed in the Wise and Clintwood area during the 1977-78 Winter Season.

It is not known how much snow fell in upper elevations of the High Knob Massif during this 1977-78 season; however, given snow amounts during the past 25 years have tended to be double or more than observed in Wise and Clintwood  it was a significant amount.

The 1977-78 Winter produced an official snowfall total of 26.2″ in the Tri-Cities of the Great Valley of northeastern Tennessee, with 21.1″ in Knoxville.

Original National Weather Service Data Forms submitted by Roy L. Wells, Jr., for the official station of Wise 1 SE located on the campus of University of Virginia’s College At Wise.

The 1976-77 Winter Season

October 1976

November 1976

December 1976

January 1977

February 1977

The observation site of Wise 1 SE had a southern exposure at its elevation of 2560 feet above sea level, so it represents the least amount of snow cover days for the middle elevation zone.

The observation time of 5:00 PM, in addition, tends to represent less snow depth than stations where the recorded 24-hour snow depth is during the morning ( i.e., snow depths often decrease during afternoon hours even during some snowstorms unless temps are very cold and snow is falling steadily to heavily ).

The harsh nature of the 1976-77 winter is illustrated by weather records of Elizabeth & Addison Stallard, which show snow cover visible across the head of Powell Valley from December 20, 1976 to March 11, 1977. A continuous stretch of 82 days! Quite impressive for a snow shadowed locale which typically has only a fraction of snow cover days observed across the high country above.

**Northern slope sites, especially in upper elevations, had almost constant snow cover from mid-November into mid-March during the 1976-77 winter.

March 1977

Although 68″ of snow were measured in Wise during the November-March period of the 1976-77 Winter, total water equivalent precip was much below average with only 10.16″  during these 5 months ( a winter dominated by cold air and  mostly low density falls of snow ).

That changed rapidly in early April 1977.

April 1977

A total of 7.75″ of mostly rain fell in Wise during April 2-5 as part of the Great Flood of April 1977.  More precipitation in water equivalent form than measured during the entire November-February period combined.

Rainfall totals of more than 12.00″ were estimated by a follow up study along windward facing mountain slopes, with the High Knob Massif likely having among the most.

*A total of 0.8″ of snow fell at the end of this event in Wise, with 2-3″+ of snow falling in parts of the mountain area at the conclusion of this flood.