Beginning Of Meteorological Summer_High Knob Lake Basin
The coldest opening to a June on record in Wise was in 1966 with 31 degrees (that same morning featured 30 degrees in Burkes Garden).
The coldest opening to a June on record in Burkes Garden was in 1930 with 26 degrees, while the coldest on record in Canaan Valley (WV) reached 24 degrees in 1960.
Wise Temperatures For 1 June_1973-2019
While all-time record mins will remain safe, the coldest temperatures in several decades will be likely on early Monday this year, with coldest temperatures in the 30s amid high mountain valleys (widespread 40s to around 50 degrees within many other locations).
Burkes Garden Temperatures For 1 June_1973-2019
Light gradient winds, clear skies, and a unseasonably large 850 MB dewpoint depression will generate frost in cold air collecting basins at upper elevations from the High Knob Massif to Canaan Valley.
The northern frost pocket site in Canaan Valley, West Virginia will have a chance to drop into the 20s and approach the all-time record MIN for June 1 in Canaan Valley, and the all-time MIN for the month, which can be followed at this link.
NAM 12 KM Model_850 MB Wind Streamline Forecast_8 AM Monday_1 June
Humid-Unsettled Pattern Ahead
Developing upper air ridging across the USA will feature a separation in the ridge over the Southeast and Gulf Of Mexico, increasing the opportunity for unsettled conditions and possible tropical develop-ment over the Gulf by later in this period.
European Ensemble Mean_500 MB Height Anomaly_2-7 June 2020
A dramatic transition from unseasonably cool to unseasonably warm air will occur as this pattern develops, with hit-miss to widespread showers and downpours in thunderstorms becoming likely.
European Model_850 MB TEMP Anomaly Forecast_2-7 June 2020
*High water levels will continue along Big Stony Creek, Little Stony Creek, South Fork of Powell River and other steep creeks draining the high country along the Wise-Scott-Lee border area, as well as portions of Black Mountain, into today (Monday, 25 May 2020).
*A warm, moist air mass will dominate the mountain region through this week with hit-miss showers and downpours in thunderstorms.
The potential for local high water will continue with development of torrential rain producing showers and thunderstorms. Folks living and driving along streams and within flood prone locations should remain alert for the potential of rapid water level rises. This includes those hiking in remote locations of the High Knob Massif and Jefferson National Forest.
*An increase in moisture in advance of a strong cold frontal boundary, which may in part be contributed to by tropical moisture transport, will increase the coverage of showers-thunderstorms later this week into the early weekend.
*Much cooler air is being monitored for later this weekend into early next week during the transition into Meteorological Summer and the month of June.
ECMWF Model_850 MB Temperature Anomaly_8 PM on 31 May 2020
Locally heavy to excessive rainfall amounts will be possible, but upper lows are notoriously difficult to predict exactly where bands forming around their swirling circulation will develop.
Waves rotating aloft around upper-level lows tend to support low-level convergence zones at the surface, with these being difficult to predict in advance of their development. Since it is impossible for air to go downward into the ground, low-level convergence mandates rising air with subsequent cooling and condensation to support precipitation formation.
If the upper low remains stationary from one day to the next, corridors that receive heaviest rain amounts during day 1 may again be impacted on day 2, especially if over terrain locations where tree leaves have fully matured and evapotranspiration is running at a maximum level to support a positive feedback for wetness.
If the upper low moves from one day to the next, the corridor that receives heaviest rainfall amounts also tends to move as the low-level convergence becomes focused, or enhanced, along a new corridor.
The potential for heavy to excessive rainfall is enhanced if these upper-level low generated convergence zones (where air rises) phase with orographic forcing and become superimposed on air flow trajectories which are naturally forced to rise by terrain barriers.
NAM 12 KM Model_Total Rainfall Forecast_12z Saturday Run
Large run-to-run model variations for any given spot indicates the uncertainty for a given spot, but persistent replication of heavy-excessive amounts indicates that some places will tend to get much more rain (with possible high water issues) than other locations this upcoming week.
NAM 12 KM Model_Total Rainfall Forecast_18z Saturday Run
NOWCasting is a favored term used to describe this type of forecast scenario, where heavy rain potential is best resolved once rain bands begin forming during any given day around the upper low.
European Model_850 MB Temp Anomaly Forecast_18-24 May 2020
Near average to below average temperatures will occur mainly due to clouds and rainfall, impacting maximum temperature most relative to average.
*Another significant wave of rain will give way to much colder air Friday night into Saturday, with a change to snow and mixed precipitation.
*A dusting up to 2″ of snow accumulation will be possible, mainly at elevations above 3000 feet into early Saturday (locally higher amounts will be possible on peaks above 4000 feet).
Air temperatures will vary from upper 10s to lower 20s (with much colder wind chills along ridges) on highest peaks to lower 30s in warmer valleys.
Wind chill factors will drop into single digits above and below zero, especially in gusts, along highest mountain ridges during Friday night into Saturday AM. Bitterly cold for early May.
*Good radiational cooling conditions will allow coldest temperatures Saturday night into early Sunday to develop within mountain valleys, with widespread below freezing temperatures.
*An additional push of unseasonably cold air will again set the stage for more freezing to below freezing conditions centered on 12-13 May 2020.
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.
500 MB Height Anomaly Pattern_May 1989
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!
Official_National Weather Service Record_Clintwood VA
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.
1 Mile SE of Wise Courthouse_Campus of Clinch Valley College
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.
Burkes Garden Basin_May 1989
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.
Canaan Valley Basin_May 1989
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).
Tri-City Airport_Great Valley of Northeast Tennessee
Cold air collecting basins, at upper elevations above 3000 feet, tend to be coldest on nights conducive for radiation cooling.
ALERT For Waves Of Heavy Rainfall With The Potential For Locally Strong-Severe Thunderstorms
*Waves of heavy rainfall will impact the mountain region today, with the chance for locally strong to severe thunderstorms.
Severe Thunderstorm Risk_8 AM Tuesday-8 AM Wednesday_5-6 May 2020
Stay tuned to NOAA Weather Radio and your favorite media sources for possible watches and warnings which may be needed.
*The first wave of unseasonably cold air will impact the mountain area during Wednesday-Thursday AM of 5-6 May.
*A second, stronger wave of record-level cold air is expected to impact the mountain region by the upcoming weekend (centered on 9-10 May 2020).
Previous Statements
*A chilly dawn Saturday will give way to a much warmer afternoon. This welcomed break in the relentless wetness of 2020 should be enjoyed.
Update: Temperatures dropped below freezing in colder mountain valleys at upper elevations in the High Knob Massif, with low-mid 30s observed within colder middle to lower elevation valleys. A few specific minimums included 33 degrees on Hurricane Road (Wise Plateau), 36 degrees in City of Norton and 36 degrees at Clintwood 1 W. Certainly cold enough for areas of frost.
*This wet and stormy pattern will renew itself by Sunday night into Monday, and persist into much of next week. More significant to locally excessive rain will be likely (with placement of heaviest rains to be determined in coming days).
Although a rain shower can not be ruled Sunday afternoon, the best rain chances will develop Sunday evening into the overnight-early morning hours of Monday to mark the first wave of several to impact the soggy mountain landscape next week.
*An unseasonably cold pattern for early May is also being monitored for the potential of record low temperatures in the 7-10 day forecast period.
European Ensemble Mean_500 MB Height Anomalies_6-11 May 2020
*A classic setting for unseasonably cold temps, perhaps record cold, is being predicted to develop by the 51-member European Model ensemble mean.
European Model_850 MB Temperature Anomalies_8 AM on 9 May 2020
Timing and intensity is subject to change, of course, at this distance, but this has been a persistent trend and will be expected to develop toward the end of the first week of May or beginning of the second week (the above would create record cold temperatures on the morning of May 9).
Wet & Chilly Pattern In April 2020
April Precipitation Totals (Ending 7-9 AM on 30 April)
Eagle Knob of High Knob Massif 12.40″
Big Cherry Lake Dam of High Knob Massif 11.59″
Robinson Knob-High Chaparral of High Knob Massif 11.46″
*City of Norton Water Plant 10.09″
*The wettest April on record since 1983, just beating the 10.07″ observed during April 1998. No records are available for what would have been the wettest April in 1977.
**Clintwood 1 W 8.68″
**The second wettest April on record at Clintwood 1 W (1964-present), just behind the 9.05″ observed during April 1998. A total of 8.17″ fell during April 1977 (mostly in the 3-5 April flood event).
***Wise (UVA-Wise) 8.63″
***The third wettest April on record in Wise behind the 9.24″ in April 1998 and the 9.59″ in April 1977 (record period 1956-present). The bulk of rain in 1977 fell during the great flood event of 3-5 April.
Up to 15.00″ of rainfall were estimated during the benchmark flood event of April 1977, with orographic enhancement in favored locations on SW air flow trajectories (High Knob Massif-Landform and localized portions of Tennessee Valley Divide).
Jonesville 3.1 WSW 8.09″
Total Precipitation – Fast Start To 2020
Draining Big Cherry Basin – South Fork Gorge of Powell River
Precipitation Totals: Ending AM of 1 May 2020
Eagle Knob of High Knob Massif 43.45″ (M)
Big Cherry Dam of High Knob Massif 41.49″
City of Norton Water Plant 34.79″
Jonesville 3.1 WSW 32.38″
Appalachia Lake Water Plant 32.26″
Clintwood 1 W 29.12″
Coeburn Filter Plant 28.66″
Wise (UVA-Wise) 28.13″
Long Ridge (Nora 4 SSE) 24.01″
A torrid precipitation pace, for the third consecutive year, has produced amounts within wetter portions of the High Knob Massif which have exceeded the long-term annual average for the state of Virginia!
The insane aspect, of course, it’s only taken 4 months. There are 8 more months to go!
