Any Mid-Late Week Storm Could Be Strong & Produce Torrential Rainfall In Downpours. A Slight Risk For Severe Thunderstorms Has Been Issued By The Storm Prediction Center For Thursday ( June 16 ).
The Mountain Empire will remain within a thermal-moisture gradient this week, with a large contrast in temperatures and dewpoints across the region. This gradient will be fluctuating back and forth across the Cumberland Mountains.
Monday Night Into Tuesday Morning
Mostly clear. Large vertical temperature spread between mountain ridges and much cooler valleys. Light & variable winds below 2700 feet. Winds SSW-WNW at generally less than 10 mph along mountain ridges above 2700 feet. Temps varying from 40s in mountain valleys to the 50s to around 60 degrees along exposed middle elevation ridges-plateaus ( extremes varying from 38 to 44 degrees in colder valleys of mid-upper elevations amid the High Knob Massif-Burkes Garden corridor to low-mid 60s at lower elevations in the Tennessee Valley southwest of the Tri-Cities ).
Tuesday Afternoon
Increasing mid-high clouds ( some cumulus possible ). Becoming hazy & more humid late. Hotter. Slight chance of a hit-miss shower or storm by late afternoon. Light and variable winds. Temperatures varying from 70s in upper elevations to the middle 80s to around 90 degrees ( hotter south toward the Tri-Cities ).
Tuesday Night Into Wednesday Morning
Hazy & humid. Chance of showers and downpours in thunderstorms ( especially overnight toward morning ). Light winds, except S-SW at 5-10 mph, with some higher gusts, along mountain ridges above 2700 feet. Warm with temperatures mostly in the 60s to around 70 degrees.
Wednesday Afternoon
Humid & hazy with a chance for showers & downpours in thunderstorms. Winds SSW-WSW at 5-10 mph, with some higher gusts ( stronger in storms ). Temperatures varying from low-mid 70s to lower-mid 80s ( coolest in the upper elevations ).
Wednesday Night Into Thursday Morning
Chance of showers & downpours in thunderstorms. Humid. Winds SW to NNW at 5-15 mph, with higher gusts, on mid to upper elevation mountain ridges & plateaus. Temperatures widespread in the 60s.
Thursday Afternoon & Evening
A chance of showers & downpours in thunderstorms. Some storms could be strong to locally severe. Winds W-NW 5-15 mph, with higher gusts, along mid-upper elevation ridges and plateaus. Afternoon maxs varying from 70s at highest elevations to the 80s to around 90 degrees.
Weather Discussion ( June 12-16 )
Early Thursday Update
A hit-miss array of showers & downpours in thunderstorms impacted the mountain area during Wednesday ( June 15 ).
Conditions Wednesday marked a significant change from morning lows in the low-mid 40s in colder mountain valleys during the AM of June 14 as the region was again engulfed by steamy air on the moist side of a notable temperature-moisture gradient.
Summer Thunderstorms Form Above Dickenson County VA – June 15, 2016
The Storm Prediction Center has the mountain area in a slight risk for severe thunderstorms today ( June 16 ).
Storm Prediction Center Risk Regions For June 16
The greatest risk today, with an Enhanced Region, is forecast to be centered upon either side of the West Virginia-Virginia border to the northeast of the Mountain Empire.
Storm Prediction Center Discussion For June 16
Stay tuned to NOAA Weather Radio for any possible watches and/or warnings that may be needed today.
Previous Discussion
A gorgeous Monday is being observed across the mountains with beautiful blue skies and low dewpoints. Although the sun is a dynamo at this time of year, and feels hot in direct light on any day, air temperatures have been pleasant with readings varying from lower 70s to lower 80s.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Monday afternoon temperatures have peaked in the lower 70s ( at higher elevations in the High Knob Massif ) to the upper 70s to low 80s ( 83 degrees in Clintwood ).
Nora 4 SSE – NWS Station In The Middle Elevations – Elevation 2650 feet
Both temperatures and dewpoints are much higher to the south into the Tennessee Valley, from the Tri-Cities south and southwest. This will generate a large temperature difference tonight into early hours of Tuesday.
*As of 6:30 PM the official NWS temperature in Clintwood had fallen from 83 degrees to 71 degrees ( to illustrate the cooling potential that will develop amid valleys as the sun continues to sink beneath the mountain horizon ).
NAM 4 KM Model Dewpoint At 8 AM Monday – June 13, 2016
The moisture gradient set up across the region Monday is very notable, with pleasant low dewpoint air north and northeast of the Tri-Cities and Tennessee Valley.
HRRR Model Surface Dewpoints At 3:00 PM Monday – June 13, 2016
With clear skies, light winds, and low dewpoints the air temp will drop significantly tonight into Tuesday AM in mountain valleys within and northward to northeastward of the High Knob Massif ( MINS by Tuesday Morning could vary by more than 20 degrees along N-S and NE-SW tran-sects across far southwestern Virginia and NE Tennessee- southern Kentucky across this moisture gradient ).
NAM 4 KM Model Dewpoint Forecast At 8:00 PM Wednesday – June 15, 2016
This large moisture gradient will be gone by mid-week, with showers & downpours in thunderstorms increasing across the mountain landscape by Wednesday into Thursday.
Rainfall Amounts Since May 1
Some local showers and storms made it into portions of Dickenson & Buchanan counties during Sunday, with the bulk of rainfall activity focused over northern Kentucky into southern portions of West Virginia.
Observed Rainfall During Sunday ( June 12, 2016 )
During the past 30+ days, since May 1, rainfall totals have varied significantly across the Mountain Empire with much more rain along and north of the High Knob Massif versus locations to the south.
Rainfall Totals May 1-June 13
Clintwood 1 W 8.29″
City of Norton WP 8.81″
Tri-Cities NWS 4.89″
*Totals in the High Knob Massif since May 1 have reached into the 10.00″ to 12.00″ range ( wettest locations being from portions of the Bark Camp Lake-Little Stony Creek basin into sections of the Big Stony Creek and South Fork of the Powell River basins ).
USA Drought Monitor As of June 7, 2016
Much drier conditions to the south were reflected by the USA Drought Monitor last week ( even though local conditions are generally not well represented across complex terrain ).
The Black Mountain MesoNET station has recorded 8.18″ of rain since the beginning of May. A recap of daily conditions:
Black Mountain MesoNET For May 2016Black Mountain MesoNET For June 1-12, 2016
Humidity, heat, and haze will be increasing into this weekend along with chances for at least hit-miss showers & thunderstorms ( especially by late Saturday into Sunday ). Slow down and take it easy as heat-humidity increases.
Thunderstorms could become strong to locally severe if clusters develop amid WNW-NW flow ( with potential for activity passing north of the Cumberlands initially to generate outflow boundaries that function as new trigger zones…stay tuned for later updates ).
Overnight Into Friday Morning
Partly cloudy ( high clouds ). Light and variable winds. Temperatures varying from low-mid 40s in cooler valleys to the 50s across mid-upper elevation ridges-plateaus.
Friday Afternoon
Partly to mostly sunny ( high clouds ). Light WNW-N winds. Warmer with MAX temperatures varying from low-mid 70s in upper elevations to the low-mid 80s. Some increase in humidity and haze.
Friday Night Into Saturday Morning
Partly cloudy ( some high clouds ). Light S-WSW winds less than 10 mph along middle elevation ridges below 2700 feet. Winds SW to WNW at 5-10 mph, with some higher gusts, on mountain ridges above 2700 feet. MIN temperatures from low-mid 50s in cooler mountain valleys to the low-mid 60s.
Saturday Afternoon
Partly cloudy. Significant increases in humidity & haze. Hotter. Chance of a shower or thunderstorm. Winds W at 5-10 mph. MAX temperatures varying from mid-upper 70s in upper elevations to the mid to upper 80s ( hotter to the south toward the Tri-Cities ).
Saturday Night Into Sunday Morning
Hazy, warm & humid. Chance of a shower or thunderstorm ( especially in northern locations ). WSW-WNW winds 5-15 mph, with higher gusts, along middle elevation mountain ridges and plateaus below 2700 feet. Wind WNW-NW 10-20 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures varying from 60-65 degrees in cooler valleys to around 70 degrees on exposed mountain ridges.
Sunday Afternoon
Partly to mostly cloudy. Chance of showers & downpours in thunderstorms. Some storms could be locally strong-severe with damaging winds. Winds WNW-NW at 5-15 mph, with higher gusts. Temperatures varying from lower 70s to the lower to middle 80s ( coolest at highest elevations ).
An increasingly stormy pattern into next week will need to be monitored for the potential of heavy to locally excessive rainfall amounts, as well as strong-severe thunderstorms. Stay tuned for later updates in coming days at the pattern becomes more clear.
Weather Discussion ( June 9-12 )
A spectacular June air mass graced the mountain landscape during Wednesday into Thursday, with unseasonably cool temperatures that featured MINS in the 30s to lower 40s within mountain valleys by early hours of June 9.
Spectacular Air Mass In Cumberland Mountains – June 9, 2016
Seasonally cool conditions continued to be featured through Thursday ( June 9 ) with PM MAXS varying from 60s at highest elevations in the High Knob Massif to the upper 70s to around 80 degrees at lower elevations.
European Ensembles MEAN 500 MB Height Anomalies – DAYS 1-5
A persistent WNW to NW flow pattern will be featured during coming days, with a huge heat ridge centered across central portions of the USA in the MEAN.
While a upper low could form and cut-off beneath the heat ridge, there will be a significant trough over or near New England to generate a baroclinic zone regardless of upper low formation.
European Ensembles MEAN 500 MB Height Anomalies – DAYS 6-10
This type of pattern will tend to keep the hottest air suppressed to the south and west of the Cumberlands as debris clouds ( blow off from upstream thunderstorms ) in this WNW-NW flow works together with terrain induced cloud formations to hold temperatures back a little more than would otherwise occur ( as is predicted by feedback from a wet May 1 to June 6 period ).
*It will still be hot, but not as intense or as prolonged in nature given May 1 to June 6 wetness. This wet period will now become an important factor as evapotranspiration from trees and vegetation feeds into the overlying air in coming days to help increase clouds and chances for showers and thunderstorms ( by next week this could aid formation of an increasingly stormy, wet pattern ).
Although details remain to be worked out, it appears that a persistent northeastern USA upper trough will enhance a temp gradient that aids thunderstorm development across the Great Lakes and Upper Midwest in coming days, with debris cloudiness ( initially ) advecting southeast across the Appalachians to partially filter insolation. A local shower or thunderstorm could develop off the terrain Saturday.
Thunderstorm chances will increase along a front that forms in the temperature gradient by Saturday Night into Sunday, as haze, humidity levels increase significantly.
Next week a upper level low may form beneath the heat ridge ( or a WNW-NW flow will persist ) to enhance the risk for showers and downpours in thunderstorms. Depending upon how this may play out, a heavy to excessive rainfall potential could arise and will need to be closely followed along with the chance for strong-severe storms.
GFS Model Total Rainfall Forecast Next 16 DAYS – 2 PM June 9 Run
Forecast models will jump around with heaviest rain amounts, but the signal for heavy to excessive rainfall totals is there on the GFS and European ( most importantly ) models and many ensembles.
GFS Model Total Rainfall Forecast Next 16 DAYS – 8 PM June 9 Run
Meanwhile, slow down and take it easy as the first surge of true summer heat & humidity develops into this weekend.
Partly to mostly cloudy. Cooler. WNW to NW winds decreasing to less than 10 mph along middle elevation ridges below 2700 feet. WNW-NW winds 5-15 mph, with higher gusts, along upper elevation mountain ridges. Temperatures varying from middle to upper 40s to the middle-upper 50s.
Wednesday Afternoon
Partly-mostly sunny. Blue skies. Unseasonably cool for the season with NW-NNW winds at 5-10 mph ( higher gusts on mid-upper elevation ridges ). Temperatures varying from 50s at highest elevations to the middle 60s to lower 70s.
Wednesday Night Into Thursday Morning
Mostly clear and unseasonably cold. Light winds along middle elevation ridges-plateaus. NNW-N winds 5-10 mph on upper elevation mountain ridges. Temperatures varying from upper 30s to lower 40s in coldest valleys of mid-upper elevations to the middle 40s to lower 50s. Areas of fog possible, especially along major river valleys & lakes.
Thursday Afternoon
Mostly sunny. Light W-NW winds. Temperatures varying from 60s across upper elevations to the 70s in middle to lower elevations ( warmer south toward the Tri-Cities ).
Thursday Night Into Friday Morning
Becoming partly to mostly cloudy. W to NW winds 5-15 mph along mid-upper elevation mountain ridges. Temperatures varying in the 40s and 50s ( coolest in mountain valleys ).
Weather Discussion ( June 7-10 )
A refreshing air mass overspread the mountain area during Tuesday ( June 7 ), with much lower dewpoints ( humidity ) and beautiful blue skies. An early summer treat!
Refreshing June Air Mass – American Beech & Yellow Poplar – June 7, 2016
Afternoon MAXS varied from 60s in upper elevations to the lower-middle 70s within middle elevations ( between 2000-3000 feet ) to the upper 70s to around 80 degrees in lower elevations.
Remember I break my forecast’s down by elevation zones:
Lower Elevations Below 2000 Feet
Middle Elevations 2000-3000 Feet
Upper Elevations Above 3000 Feet
*With respect to boundary layer conditions I often divide middle and upper elevations at the 2700 foot level. This allows for the upward bulge generated amid the atmosphere by the High Knob Massif where many valley floors rest at or above 2700 feet.
The boundary layer refers to that portion of the lower atmosphere which is in contact with the Earth’s surface. It is often defined as the friction layer, or that part which is most influenced by terrain generated drag.
The boundary layer tends to expand during the day with thermal heating and contract by night with cooling. In complex terrain, such as that within the High Knob Massif area, multiple inversion layers develop at different levels on any given night if decoupling ( detachment ) occurs ( i.e., winds decrease and become detached in valleys from more organized winds amid the boundary layer, or blowing along its top, and are replaced by cold air drainage flows and associated circulations ).
Nora 4 SSE – NWS Station In The Middle Elevations
The official NWS MAX in Clintwood reached 79 degrees on June 7, with a temperature drop to 56 degrees observed by Midnight.
While there will be plenty of dew forming on roses and other flowers in coming nights, it will come very close to turning frosty amid coldest valleys of middle to upper elevation within the High Knob Massif-Burkes Garden corridor into morning hours of Thursday ( June 9 ).
Red Rambling Rose ( Rosa spp. ) Escaped Into The Wild – June 2016
Mean dewpoints in the 30s within the 900 to 850 MB zone will be able to generate significant cold air drainage, amid light winds and mostly clear skies, with valleys above 2000 to 3000 feet becoming coldest during Wednesday Night into Thursday AM.
European Model 850 MB & Surface Analysis At 8 AM Tuesday – June 7, 2016
The current autumn-winter like upper air pattern will change radically into this weekend and next week, at least for much of the nation outside of New England where a chilly pattern looks to hold on beneath upper troughing.
European 51-Member Ensemble 500 MB Height Anomalies MEAN: Days 1-5
A pattern like this in June typically signals a battle zone with showers & thunderstorms moving around the peri-phery of hottest air. Exactly where this sets up into the weekend and next week will dictate how wet ( or not ) it becomes within the Mountain Empire.
European 51-Member Ensemble 500 MB Height Anomalies MEAN: Days 6-10
Meanwhile, be sure to enjoy a few gorgeous days of awesome June conditions in the southern Appalachians!
Chance of hit-miss showers. Areas of dense fog. Light winds below 2700 feet. W-WNW winds 5-10 mph, with higher gusts, along mountain ridges above 2700 feet. Temps in the 50s to around 60 degrees.
Monday Afternoon
Partly cloudy. Continued warm and relatively humid. Chance of a hit-miss shower or thunderstorm. Light WSW to WNW winds generally less than 10 mph. Temperatures varying from lower 70s at highest elevations to the lower to middle 80s.
Monday Night Into Tuesday Morning
Chance of an evening showers or thunderstorm. Then partly-mostly clear. Areas of dense fog. Winds SW to W at 5-10 mph along mountain ridges-plateaus below 2700 feet. Winds W-NW 5-15 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures in the 50s to low 60s.
Tuesday Afternoon
Partly cloudy. Becoming much less humid. Winds W to NW at 5-15 mph, with higher gusts. Temperatures varying from 60s at highest elevations to mid 70s to around 80 degrees.
Tuesday Night Into Wednesday Morning
Partly cloudy. Cooler. WNW-NW winds 5-15 mph, with higher gusts along upper elevation ridges. Temperatures varying from upper 40s to the mid-upper 50s.
Mountain valley temperatures could dip into the upper 30s to middle 40s during Wednesday Night into Thursday Morning, coldest within mid-upper elevation valleys.
A wave of summer heat will begin building across the Tennessee Valley into the southern Appalachians by this weekend into early next week. This may trigger thunderstorm development of the air mass variety initially, then the potential for clusters of storms by next week could bring a heavy-excessive rainfall potential. Please stay tuned for updates on a changing June weather pattern.
Weather Discussion ( June 4-8 )
An array of showers and downpours in thunderstorms were observed during the weekend.
As the pressure gradient began increasing orographic clouds formed along the High Knob Massif, with both wave and pilatus cap clouds becoming visible during late Saturday ( June 4 ). This set the stage for heavy rain into the overnight and Sunday.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Some amazing and strikingly beautiful cloud formations were observed during Sunday afternoon-early evening.
High Knob Massif Webcam – University Of Virginia’s College At Wise
A general 1.00″ to 2.00″+ of rainfall into Sunday boosted June rain tallies into the 3.00″ to 5.00″+ category across much of the High Knob Massif area, with roaring water observed on steep creeks draining the massif.
Big Stony Creek Stream Gage – May 31 Through June 1-5, 2016
While a hit-miss shower or thunderstorm will remain possible through Monday, a much drier air mass and refreshing change will be felt during Tuesday and Wednesday when seasonally cool temperatures will overspread the mountain region.
A Small Virginia Land Snail Species – June 2016
Temperatures in cooler mountain valleys will drop into the 40s during mid-week, with even some upper 30s to lower 40s being possible in colder valleys of mid-upper elevations.
Appalachian Barren Strawberry ( Geum fragarioides ) – June 2016
The focus by the end of this week into this upcoming weekend will shift to building heat. The first true heat of the Summer 2016 season. Given May-early June wetness, the potential for thunderstorm formation will have to be respected, with cloud formation and such activity dictating how hot temperatures will get in many places ( the trend favoring heat that breaks by storms and the potential of a heavy to potentially excessive rainfall setting next week ).
ALERT For Locally Heavy Rain With Downpours In Showers & Thunderstorms From Thursday Into This Weekend ( Hit-Miss Coverage At Any Given Time ). Some Storms May Be Strong To Locally Severe.
The Storm Prediction Center Has Issued A Slight Risk Of Severe Thunderstorms For The Area Between 8 AM Saturday and 8 AM Sunday
The threat for downpours in showers & thunderstorms will continue into Sunday ( and become likely Saturday Night Into Sunday ). Remain alert for changing conditions during outdoor activities this weekend.
Overnight Into Thursday Morning
Chance of showers & thunderstorms. Mostly cloudy. Areas of dense fog. Light and variable winds on mountain ridges and plateaus below 2700 feet. Winds SSW-WSW 5-10 mph, with higher gusts, on mountain ridges above 2700 feet. Warm & humid with temperatures mostly in the 60s.
Thursday Afternoon
Hit-miss showers & thunderstorms. Locally heavy rainfall. Winds SSW to WSW at generally less than 10 mph outside of storms. Temperatures varying from upper 60s to low 70s in upper elevations to the mid 70s to around 80 degrees.
Thursday Night Into Friday Morning
A chance of showers & thunderstorms. Locally heavy rainfall possible. Areas of dense fog. Winds SSW-WNW at generally less than 10 mph outside of storms. Warm and humid with temperatures widespread in the upper 50s to lower-middle 60s.
Friday Afternoon
Hit-miss showers & thunderstorms. Locally heavy rainfall. Winds SSW to WSW at generally less than 10 mph outside of storms. Temperatures varying from upper 60s to low 70s in upper elevations to the mid 70s to lower 80 degrees.
Friday Night Into Saturday Morning
A chance of showers & thunderstorms. Locally heavy rainfall possible. Areas of dense fog. Light & variable winds along mountain ridges-plateaus below 2700 feet. Warm & humid with temps in the upper 50s to lower-middle 60s.
*Some storms could become strong to locally severe during the Saturday afternoon into Sunday period. Low-level flow will increase during Saturday Night into Sunday AM to also increase orographic forcing into favored zones such as that of the High Knob Massif-Black Mountain corridor.
Saturday Afternoon
Hit-miss showers & thunderstorms. Locally heavy rainfall. Winds SSW to SW at 5-15 mph, with higher gusts, along mid to upper elevation mountain ridges and plateaus. Humid. Temperatures varying from low-mid 70s at the highest elevations to the lower-middle 80s.
Saturday Night Into Sunday Morning
Showers & downpours in thunderstorms becoming likely. Locally heavy rainfall. Winds SSW to SW 5-15 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet. Winds SW-WSW 10-20 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures from the upper 50s to mid-upper 60s.
Sunday Morning Into Sunday Afternoon
Showers & downpours in thunderstorms. Locally heavy rainfall. Winds SSW-WSW at 5-15 mph, with higher gusts. Temperatures varying from the 60s to lower-middle 70s.
Weather Discussion ( May 31-June 4 )
Early Saturday Update
While hit-miss showers and downpours in thunderstorms will be possible Saturday, they will become likely during Saturday Night & Sunday as a cold front pushes east into the Appalachians. Some storms could be strong to severe from Saturday afternoon into Sunday.
Early Summer Thunderstorms Form – High Knob Massif
Reference Early Summer 2016 In The Appalachians for more photographs of dramatic skies above the High Knob Massif as thunderstorms began erupting Thursday afternoon ( June 2 ).
The High Knob Massif, especially central-eastern portions, have been a focus for heavy rainfall during the past few days.
Doppler 36-Hour Estimated Rainfall Ending 12:08 AM on June 3, 2016
Locations in the RED on the above graphic had an estimated 2.00″ to 3.00″+ of rainfall during the 36-hour period ending at just after midnight on June 3 ( 12:08 AM ). The heaviest rains being focused upon the Little Stony Creek Basin ( from above Bark Camp Lake to along Little Stony Gorge ) and eastern sections of the Big Stony Creek Basin ( in the Glades ).
Strong water level rises, with ROARING whitewater, were observed on both Little Stony Creek and Big Stony Creek.
NAM 12 KM Model Total Rainfall Forecast Next 84-Hours
Forecast models continue to show an increasing coverage of showers-thunderstorms by later Saturday & Saturday Night into Sunday.
GFS Model Total Rainfall Forecast Next 84-Hours
The GFS ( above ) keeps more of a hit-miss pattern while the NAM and European models forecast widespread coverage to develop into Saturday Night and Sunday. The European is placing the heaviest rainfall corridor across far southwest Virginia and extreme southeastern Kentucky, as well as along portions of the lower Tennessee Valley and plateau.
Storm Prediction Center Risk Region To 8 AM Sunday
The Storm Prediction Center has the entire area within a slight risk for severe thunderstorms between 8:00 AM Saturday and 8:00 AM Sunday.
Probability Of A Tornado Within 25 Miles Of A Given Point
Wind damage will be the greatest severe risk parameter, outside of always dangerous lightning and downpours of heavy rainfall.
Probability Of Wind Damage Within 25 Miles Of A Given PointStorm Prediction Center Discussion
An added factor will be increasing pressure gradient winds and enhancement of orographic forcing by Saturday Night into Sunday in advance of a upper air trough and surface cold frontal boundary. This will favor a heavy to excessive rainfall potential for the High Knob Massif-Black Mountain corridor on general SW air flow trajectories.
Please remain alert to changing conditions this weekend and keep NOAA Weather Radio and mobile devices handy when outside to monitor the potential for strong to locally severe storms and heavy rains.
Previous Discussion
A summery air mass will remain in place across the Mountain Empire into this weekend with a array of showers and downpours in thunderstorms.
Doppler Rainfall Estimate For Tuesday – May 31, 2016
The pattern observed during May 31-June 1 will be repeated, with an increasing coverage, into this weekend. Downpours of 0.50″ to 1.00″+ have been observed and can easily occur in the stronger or more persistent activity on any given day.
Between 1.00″ and 2.00″ of rain fell from Bark Camp Lake across much of the Little Stony Creek Basin into the Guest River Gorge area during June 1 as persistent, back-building storms developed over eastern portions of the High Knob Massif ( below ). Additional heavy action form along portions of Black & Pine mountains to the NW-N of Norton & SW of Pound.
Doppler Radar Rainfall Estimate For Wednesday – June 1, 2016
While heating generally offers the best development, showers & downpours will not be restricted to just the daylight hours amid such a warm and buoyant air mass.
A tropical air mass following a wet May has turned the mountain landscape into a temperate rain forest, with many creatures great and small actively pursuing their life strategies.
Hover Fly ( Syrphidae Family ) Working Coreopsis ( Coreopsis grandiflora )
Forecast models continue to show the heavy rainfall potential, but struggle with placement of amounts.
NAM 12 KM Model Total Rainfall Forecast To 8 AM Sunday – June 5, 2016
The highest resolution version of the NAM looks like it has a bad rash, or case of the measles, as it attempts to forecast where the heaviest rainfall will fall.
NAM 4 KM Model Total Rainfall Forecast To 8 AM Saturday – June 4, 2016
All models, including the European, are on board with the heavy to locally excessive rainfall potential through this upcoming weekend.
GFS Model Total Rainfall Forecast – Next 5 Days
With luck, a drier and nice air mass will arrive for at least a while next week.
Stay tuned to NOAA Weather Radio for any possible watches and/or local warnings that may be needed through coming days.
An increasing chance of showers & downpours in thunderstorms will be observed Wednesday-Friday ( especially during afternoon-early evening hours ). Some storms may become strong to locally severe, on general principles, but torrential rainfall may end up being the main aspect that will need to be monitored most.
Overnight Into Tuesday Morning
Partly to mostly clear. Areas of fog. Light N-NE winds generally less than 10 mph along mid-upper elevation mountain ridges-plateaus. Temperatures varying from upper 40s to mid 50s in cooler mountain valleys to the upper 50s to lower 60s.
Tuesday Afternoon
Partly to mostly sunny. Warm & humid. Small chance of an isolated shower or thunderstorm. Light NNE to ENE winds at generally less than 10 mph. Temperatures varying from the low-mid 70s in upper elevations to the low-mid 80s.
Tuesday Night Into Wednesday Morning
CAUTION for Dense Fog between Little Stone Mountain Gap, and Powell Valley Overlook, and Big Stone Gap for travelers along U.S. 23 ( and old U.S. 23 heading into Appalachia ).
Partly to mostly clear. Areas of fog ( dense in Powell Valley and locations having heavy rain during Tuesday ). SE-SSW winds generally under 10 mph. Temperatures varying from 50s amid cooler mountain valleys to the low-mid 60s.
Wednesday Afternoon
Partly-mostly cloudy. Chance of showers & thunderstorms. Locally heavy rainfall possible. Light SE-S winds at mostly less than 10 mph ( outside any storms ). Warm & humid with temperatures varying from low-mid 70s at highest elevations to the lower-middle 80s.
Wednesday Night Into Thursday Morning
Chance of evening showers & thunderstorms. Partly to mostly cloudy. Areas of fog. Winds SSE to SSW 5-10 mph, with higher gusts, on mountain ridges-plateaus below 2700 feet. SSW-WSW winds 5-15 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures varying from the 50s to low-mid 60s.
Thursday Afternoon
Hit-miss showers & thunderstorms. Locally heavy rainfall. Winds SSW-WSW at generally less than 10 mph outside of storms. Temperatures varying from upper 60s to lower 70s in upper elevations to the mid 70s to around 80 degrees.
Thursday Night Into Friday Morning
A chance of showers & thunderstorms. Locally heavy rainfall possible. Areas of dense fog. Winds SSW-WNW at generally less than 10 mph outside of storms. Warm and humid with temperatures widespread in the upper 50s to lower-middle 60s.
Weather Discussion ( May 31-June 2 )
Early Wednesday Update
Local terrain triggered convection erupted in localized fashion during Tuesday, with torrential rainfall along the U.S. 23 corridor between Norton and Big Stone Gap.
Doppler Rainfall Estimate For Tuesday – May 31, 2016
A general 0.50″ to 1.00″+ of rainfall fell along U.S. 23 from near the Powell Valley Overlook, and Little Stone Mountain Gap, to the East Stone Gap area of Powell Valley. Heavy rain, which initially developed along Powell Mountain, moved across Little Stone Mountain to the Appalachia Lake Water Plant.
An area of rainfall developed earlier in the day ( early PM ) over portions of the Big Cherry Lake, Devil Fork and Straight Fork basins of the High Knob Massif, with 0.52″ of rain reported by a typically low reading automated gauge on Little Mountain. Other locations, by contrast, had little rain.
NAM 12 KM Model Total Rainfall Forecast To 8 AM Saturday – June 4, 2016
The hit-miss action of Tuesday is likely to be replicated on coming days, with heavy rainfall and strong storms hitting daily in different places. Any places that do get hit multiple times will be at higher risk for significant run-off and the possibility of strong water level rises.
GFS Model Total Rainfall Forecast Next 5 Days
Some models, like the GFS, are forecasting heavy rain amounts during the next 5 days. Models; however, are merely guessing at where the heaviest amounts will fall ( with a bias shown toward the major terrain features ). Only time will tell where heaviest total amounts will accumulate through coming days, which will partially ( at least ) be dictated by numerous sources that force convergence ( the coming together of air ) at low-levels.
Previous Discussion
Typical Memorial Day weather conditions were observed across the Mountain Empire, complete with some hit-miss showers & downpours in thunderstorms.
Memorial Day At Browning Family Cemetery – May 30, 2016
In Memory & Honor of all our loved ones lost and our veterans past and present – from the ridge top of Browning Family Cemetery.
Morning temperatures in the low-mid 50s in mountain valleys gave way to a mix of towering cumulus-cumulonimbus into the afternoon as temperatures climbed into the 70s and 80s.
Cumulus Tower Into The Heavens – May 30, 2016
Relatively dry air aloft created beautiful blue skies to set off towering afternoon-early evening cumulus ( tropical skies ).
Early Evening Cumulus Tower In Majestic Light – May 30, 2016
Light hitting a ridge top as the sun drops downward toward the western mountain horizon ( to left of above scene ).
Following a wetter and cooler than average May across much of the mountain area, the upcoming trend through the next 5 to 10 days is back toward a wetter and eventually cooler ( next week ) than average weather pattern for this time of year ( especially amid the mountains ).
European Ensembles 500 MB Height Anomalies Forecast – DAYS 1-5
A reversion back to an eastern USA upper air trough and western USA upper air ridge pattern is forecast to develop into next week.
European Ensembles 500 MB Height Anomalies Forecast – DAYS 6-10
The impact on temperatures can be seen below.
European Ensembles 850 MB Temp Anomalies Forecast – DAYS 1-5
Conditions go from above average during the first 5 days of this forecast period ( MEAN during May 31-June 4 ) to below average during the June 5-9 period ( MEAN ).
European Ensembles 850 MB Temp Anomalies Forecast – DAYS 6-10
The beginning of this pattern flip will dominate the short-term and be marked by an increasing chance for showers and downpours in thunderstorms during Wednesday into Thursday as the first cold front and upper air disturbance approaches the Appalachians.
NAM 12 KM Model Total Rainfall Forecast Up To 8 AM Friday – June 3, 2016
It is likely that some storms could become strong to locally severe given parameters being forecast by the high resolution NAM Model group for Wednesday afternoon and especially Thursday PM-early evening. Please stay tuned for updates.
This initial boundary will have a difficult time clearing the Mountain Empire as upper air troughing begins to develop and becomes reinforced by additional upstream fronts and disturbances into next week ( likely creating a stormy and unsettled period of weather that trends cool for this time of year over time ). Speaking of which, at this time of year any boundary that stalls must be closely watched given copious amounts of moisture available for showers & downpours in thunderstorms ( typically featuring widely varied rainfall amounts across the mountain landscape ).
While much dry time is expected, any shower or thunderstorm developing through this Memorial Day Holiday could contain locally heavy rainfall and always dangerous lightning.
Overnight Into Saturday Morning
Partly to mostly clear. Areas of dense fog ( especially in places that had rain on May 27 ). Winds SSE-SSW 5-10 mph, with higher gusts, along middle elevation mountain ridges and plateaus below 2700 feet. Winds S-SW 5-10 mph, with higher gusts, on mountain ridges above 2700 feet. Temps in the 50s to lower-middle 60s ( coolest in mountain valleys at middle-upper elevations ).
Saturday Afternoon
Partly cloudy and unseasonably warm. Chance of a hit-miss shower or thunderstorm. Light SSE-SSW winds at generally less than 10 mph. Temperatures varying from low-mid 70s in upper elevations to the lower-middle 80s ( upper 80s possible in lower elevations that have more sunshine ).
Saturday Night Into Sunday Morning
Partly-mostly cloudy. Chance of showers & thunderstorms. Light & variable winds ( outside any storms ). Warm with temperatures widespread in the upper 50s to upper 60s.
Sunday Afternoon
Chance of hit-miss showers and thunderstorms; otherwise, partly cloudy and warm. Light winds becoming WNW-NW at generally 10 mph or less. Temperatures varying from low 70s at highest elevations to the upper 70s to mid 80s.
Sunday Night Into Memorial Day Morning
Partly to mostly clear. Areas of fog. WNW winds 5-10 mph, with higher gusts, along middle-upper elevation mountain ridges ( especially above 2500-3000 feet ). Temperatures in the 50s to lower 60s ( coolest in mountain valleys ).
Memorial Day Afternoon
Partly cloudy. Chance of a hit-miss shower or thunderstorm. Winds WNW-NNW at 5-10 mph, with higher gusts, on middle-upper elevation mountain ridges-plateaus. Temperatures varying from low 70s at highest elevations to the upper 70s to low-mid 80s ( warmest at lower elevations to the south-southeast of the High Knob Massif-Tennessee Valley Divide ).
Weather Discussion ( May 27-30 )
Hit-miss showers & thunderstorms, some with downpours of heavy rain and booming thunder ( dangerous lightning ) developed over the mountain area Friday afternoon.
The heaviest corridor of rain stretched from southeastern Scott County north across Wise County to the Wise-Dickenson border, and across portions of the southeastern Kentucky foothills.
Rain Drops Galore On A Spider Web – May 27, 2016
The second tropical cyclone of this season is expected to increase from Depression to Storm status before reaching the eastern Carolina’s during the Holiday Weekend.
Forecast Model Tracks For TD 2 – 8 PM May 27 Run
A Tropical Storm Warning is now in effect for the entire coastline of South Carolina, and may be extended into part of the North Carolina coast pending the exact track and strength of the system ( possible T.S. Bonnie ).
National Hurricane Center Official TrackNHC Discussion At 11:00 PM Friday – May 27, 2016
While the depression is still to cross the warm Gulf Stream, upper level shear will continue to hinder development beyond a low end Tropical Storm. Things can always change, but those are current indications based upon NOAA Hurricane Hunter data and forecast models. Heavy rainfall, with inland and coastal flooding, remains a concern and should be closely monitored by anyone with travel plans to central-eastern portions of the Carolina’s.
Pink Form of Common Yarrow ( Achillea millefolium )
Meanwhile, to the north and northwest the southern Appalachians are coming under the subsidence zone along the outer periphery of this developing tropical system.
USA Water Vapor At 1:15 AM on Saturday – May 28
Sinking air through mid-levels of the atmosphere is shown above by the circular shaped zone of clear ( dark ) air across much of Virginia and the eastern portion of Tennessee into Georgia.
Saturday is likely to be the hottest day of May 2016 with air sinking over the mountain area. This will be especially true for places that do not have convection or any significant cloud development during the afternoon.
While synoptic-scale subsidence will generally work against convective development during the daylight hours of Saturday, some local terrain forced activity can not be completely ruled out and must remain in the forecast. Chances increase again into Saturday Night and Sunday as the atmosphere becomes more conducive again for rising air ( the subsidence zone weakens for locations along and west of the Cumberland Mountains ).
Remember that any thunderstorm development through the Memorial Day Holiday could contain downpours of rain and always dangerous lightning. Stay safe and have a great Holiday Weekend-Monday.
Partly to mostly clear. Areas of valley fog. Cool. Light winds below 2700 feet. SW winds 5-10 mph, with a few higher gusts, along mountain ridges above 2700 feet. Temperatures in the 40s and 50s, coolest in mountain valleys with 40 to 45 degrees in colder valleys.
Wednesday Afternoon
Becoming mostly cloudy and more humid. A chance for hit-miss showers & thunderstorms. Local downpours possible. Winds SSW-SW 5-10 mph, with higher gusts along ridges. Temperatures varying from the 60s in upper elevations to the mid-upper 70s.
Wednesday Night Into Thursday Morning
Mostly cloudy. Humid. A chance of evening showers and thunderstorms, then possible redevelopment by morning. Winds SSW-WSW at 5-10 mph along mid-upper elevation mountain ridges. Warm with temperatures in the 50s to lower 60s. Areas of haze and valley fog.
Thursday Afternoon
Partly-mostly cloudy. Hazy. A chance of hit-miss showers and thunderstorms. Local downpours possible. Winds light, except SSW-SW at 5-10 mph along middle-upper elevation mountain ridges. Temperatures varying from 60s to low 70s in upper elevations to the upper 70s to lower 80s.
Thursday Night Into Friday Morning
Any evening showers-storms dissipating. Partly to mostly clear into the overnight with haze and areas of fog. Humid. Winds SSW-SW at 5-10 mph, with higher gust, along middle to upper elevation mountain ridges. Warm with temps in the 50s to lower-middle 60s.
Weather Discussion ( May 2016 )
A final cool night amid what has been a long series of chilly nights ( dominating the May 14-25 period in the mountains ) is poised to give into summer-like humidity.
Golden Orb Weaver ( Nephilidae Family ) Species Working In Late May
A wet May 2016, with 6.37″ of rain officially measured in Clintwood, will get wetter in coming days for some as hit and miss showers and local downpours in thunderstorms develop across the mountain landscape as humidity rises.
Crown-tipped Coral ( Clavicorona pyxidata ) Growing Amid May Wetness
Forecast models are trying to guess where rain will fall during coming days, but in reality that is a very difficult thing to do when rainfall will largely be air mass-terrain driven without any distinct focus over the southern Appalachians ( unlike in the central Plains ).
NAM 12 KM Model Total Rainfall Forecast Next 84-Hours
While not cancelling any outdoor plans heading into the first big holiday to kick off Summer 2016, keep in mind that showers and thunderstorms will be developing in mostly a hit-miss fashion across the mountain landscape. Some of these will likely have downpours of rain, along with always dangerous lightning, so have a backup plan and be prepared to seek shelter.
Development odds often favor locations in and near the major terrain features, with subsequent storm motion and formation then being dictated by outflow boundaries that form as cool air rushes outward from the initial convection to trigger new stuff amid what often appears, at least, to be chaos.
GFS Model Total Rainfall Forecast Next 84-Hours
It remains to be seen how a disturbance over the western Atlantic will impact conditions by later this weekend into early next week, so stay tuned for updates.
A pocket of cold air aloft will increase the possibility of mid-late afternoon & evening showers during Sunday. Local thunder and small hail will be possible with the most well developed activity due to steep lapse rates ( 60-70 degree differences between the surface and 18,000 feet in the atmosphere ).
Overnight Into Sunday Morning
Mostly cloudy. Chance of showers. NW winds 5-15 mph, with higher gusts, along middle elevation mountain ridges and plateaus below 2700 feet. NW-N winds 5-20 mph, with higher gusts, on mountain ridges above 2700 feet. Temps varying in the 40s to lower-middle 50s ( coolest at highest elevations ). Wind chills in the upper 30s to lower 40s in gusts at highest elevations. Dense fog at elevations above 2700-3300 feet.
Sunday Afternoon
Partly to mostly cloudy. Chance of showers, especially by mid-late afternoon. Thunder & localized small hail possible. WNW-NNW winds 5-15 mph, with higher gusts ( especially along mountain ridges-plateaus ). Temperatures varying from 50s to around 60 degrees in upper elevations to the middle 60s to lower 70s.
Sunday Night Into Monday Morning
Chance of evening showers. Thunder & localized small hail possible. Becoming partly to mostly clear overnight. Areas of fog. NNW-NNE winds 5-15 mph on mid-upper elevation mountain ridges & plateaus. Temperatures in the 40s to around 50 degrees.
Monday Afternoon
Partly to mostly sunny. Winds N to NE winds 5-10 mph. Temperatures varying from 50s in upper elevations to the middle 60s to around 70 degrees.
Monday Night Into Tuesday Morning
Mostly clear. Light winds. Seasonally cool with temps in the 40s to lower-middle 50s ( coolest in mountain valleys with cold air drainage ).
A warmer pattern featuring hit-miss showers and thunderstorms is expected during mid-late week. Locally heavy rainfall will be possible with some of the thunderstorms.
Weather Discussion ( May 21-24 )
A continuation of seasonally cool, damp conditions have been observed into this May 21-22 weekend, with limited sunshine across the mountain landscape.
*A general 0.50″ to 1.00″ of rain Friday Night, in counties along the Virginia-Kentucky border, being limited by vigorous Deep South convection.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Saturday PM temperatures varied in the 50s ( above 3000 feet ) and 60s, across lower-middle elevations ( 64 degrees at Nora 4 SSE and 69 degrees at Clintwood 1 W ), amid limited sunshine and hit-miss showers featuring a few brief downpours.
Nora 4 SSE – NWS Station In Middle Elevations
Conditions late Saturday evening into the start of this Sunday are coolest in upper elevations where breezy to gusty NW-N winds are creating wind chills in the low-mid 40s.
Black Mountain MesoNET – Midnight To 1:00 AM Sunday – May 22, 2016Black Mountain MesoNET – Up To Midnight ( Sunday – May 22, 2016 )
While the weather focus will be shifting toward a warmer and more summer-like pattern into next week, there will be one more day ( Sunday ) when a pocket of cold air aloft over the mountains will steepen lapse rates ( the temperature drop with increasing height ) enough to trigger instability showers into mid-late afternoon and the early evening.
A few of the more vigorous showers will have the potential for localized small hail and thunder due to this unseasonably cold air aloft ( -4 degrees Fahrenheit below zero at 18,000 feet ).
Hairy Petunia Hybrid – Sherri’s Sassy Scissors In Clintwood, Virginia
The beauty of late Spring will be fading into early Summer soon, with conditions trending that way during this new work week toward the Memorial Day Holiday.
Dwarf Hybrid Hibiscus – Sherri’s Sassy Scissors In Clintwood, Virginia
The transition from this current cooler than average regime to one more like summer is shown well by the 51-Member European Ensemble group.
European 51-Member Ensemble 850 MB Temp Anomalies Forecast – DAYS 1-5
Temperatures will be going from below average to above average heading into late week and the Memorial Day Holiday.
European 51-Member Ensemble 850 MB Temp Anomalies Forecast – DAYS 6-10
Hit-miss showers & thunderstorms, mainly in the afternoon-evening hours, will become part of this pattern as main upper ridging develops over New England.
European 51-Member Ensembles MEAN 500 MB Height Anomalies – DAYS 6-10
ALERT For Widespread Dense Fog Continues Into Thursday AM At Middle-Upper Elevations Along & North Of The High Knob Massif-Tennessee Valley Divide – Patchy Fog Possible In Other Locations
Widespread low clouds will continue to obscure middle to upper elevations, with periods of drizzle, into the overnight-morning hours of Thursday in locations along and north of the High Knob Massif-Tennessee Valley Divide on northerly upslope flow. Cloud bases should begin to lift and dense fog-clouds break during the sunrise to mid-morning period on Thursday ( May 19 ).
Overnight Into Thursday Morning
Low clouds. Periods of drizzle. Chilly. Winds N-NE at 5-10 mph, with higher gusts, along upper elevation ridges. Temperatures in the 40s to around 50 degrees.
Thursday Afternoon
Partly cloudy or becoming partly cloudy. NE winds generally less than 10 mph. Temperatures varying from the 50s across upper elevations to the middle-upper 60s.
Thursday Night Into Friday Morning
Partly cloudy during the evening with increasing clouds overnight into morning. Winds ESE-SSE 5-15 mph along middle-upper elevation mountain ridges-plateaus. Temps in the 40s to lower-middle 50s ( coolest mountain valleys ).
Friday Afternoon
Showers developing ( especially late ). Winds SE-S at 5-15 mph, with higher gusts. Temperatures varying from the 50s at highest elevations to the middle 60s to lower 70s, warmest at lower elevations in basins of the Russell Fork and Levisa Fork of the Big Sandy River.
Friday Night Into Saturday Morning
Rain with a chance of thunderstorms. Rain may be heavy at times. Winds SE-SSW at 5-15 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet. S-SW winds 10 to 20 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures widespread in the 50s.
The potential for heavy rainfall amounts is being monitored for the Friday Night-Saturday Morning period. Strong rises on creeks will be possible, given wet May conditions ( 5.00-6.00″+ rain tallies observed during May 1-18 from the High Knob Massif into portions of the Russell Fork Basin of northern Wise & Dickenson counties ), should rainfall become heavy. Stay tuned for updates.
Weather Discussion For May 18-21
Low clouds, showers, and persistent afternoon-evening drizzle created a chilly, damp Wednesday for locations in and north of the High Knob Massif-Tennessee Valley Divide.
High Knob Massif Webcam – University Of Virginia’s College At Wise
It was a particularly nasty day amid upper elevations with dense fog all day long above 2700 feet. This combined with temperatures in the 40s, within the High Knob Massif, to put a true chill into the air on breezy to occasionally gusty northerly winds.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Cloud bases which were on and off the Wise Plateau up through Noon Wednesday dropped to obscure much of the area in persistent, dense fog from 2:00 PM to present ( 10:00 PM ).
High Knob Massif Webcam – University Of Virginia’s College At Wise
Non-radar detectable drizzle has also been a persistent feature.
Although cloud bases were just above Clintwood, the nature of this day was illustrated by a AM MIN of 54 degrees and a PM MAX of 55 degrees ( a mere 1 degree of change on the official National Weather Service MMTS System ).
Nora 4 SSE – NWS Station In The Middle Elevations
Higher up, amid middle to upper elevations, the mildest temps were observed around sunrise with a steady drop during the day as winds turned to a northerly upslope direction ( readings falling from 50s into the 40s ).
Black Mountain MesoNET
Wednesday evening temperatures have settled into low-mid 40s amid upper elevations in the High Knob Massif and Black Mountain, with enough wind to make it feel like 30s in gusts along the high ridges.
Yellow Flag Iris ( Iris pseudacorus ) – May 17, 2016
Official temperatures at and above 2700 feet have not gotten above 60 degrees since May 13, amid an extended period of unseasonably cool mid-May conditions in the mountains.
Fly ( Diptera Order ) On Waving Yellow Flag Leaf – May 17, 2016
Focus now shifts to a brief break Thursday before another storm system, taking a cold season track, spreads rain back across the southern Appalachians Friday PM-Friday Night.
Forecast models have not been consistent, from run to run, on rainfall amounts so please stay tuned for updates as a consensus is hoped for on new model runs upcoming through Thursday. The storm track & recent pattern suggests that heavy rainfall will be possible with this system ( especially if Deep South convection does not get “out of hand.” ).
