Mountain Area Forecast ( July 27-29 )

Tropical Downpours & Booming Thunderstorms Will Be Possible At Times Into This Weekend – Some Storms Could Be Strong To Locally Severe In Addition To The Greatest Threats Of Lightning & Heavy Rain That Can Cause Localized Water Problems

The period from late Wednesday into Friday afternoon will bear close watching for an increase in coverage of tropical downpours in rain showers and thunderstorms, amid a high water content air mass.  Heavy to locally excessive rainfall will be possible in places.

Remain alert if heavy rain develops over or upstream of your location.  Stay tuned to NOAA Weather Radio and your favorite media sources for possible watches, warnings, advisories.

Overnight Into Wednesday Morning

Hazy & humid.  Chance of a shower or thunderstorm.  Areas of fog.  SW-W winds generally less than 10 mph along mid-upper elevation mountain ridges.  Temperatures in the 60s to lower 70s.

Wednesday Afternoon

A chance of showers & downpours in thunderstorms.  Hazy and humid.  Light northerly winds ( outside any storms ). Temperatures varying from 70s at highest elevations to the mid-upper 80s ( hotter south into the Great Valley ).

Wednesday Night Into Thursday Morning

Hazy & humid.  A chance of showers and downpours in thunderstorms.  Areas of dense fog.  Light winds.  Temperatures in the 60s to around 70 degrees.

Thursday Afternoon

Showers & downpours in thunderstorms.  Hazy & very humid.  Winds SW-WNW 5-10 mph along mid-upper elevation mountain ridges-plateaus.  Temperatures  varying from low-mid 70s at highest elevations to the lower-middle 80s ( hotter south into the Great Valley ).

Thursday Night Into Friday Morning

Showers & downpours in thunderstorms.  Hazy & very humid.  Winds WNW-NW 5-15 mph, with higher gusts, along mid-upper elevation mountain ridges.  Temperatures in the 60s to near 70 degrees.

Friday Afternoon

Mostly cloudy with showers & downpours in thunderstorms.  SW-W winds generally 10 mph or less outside any showers and storms.  Temperatures varying from the upper 60s to lower 70s to the middle 70s to lower 80s.

Weather Discussion – Wet Vs. Dry

July 2016 has found the mountain region amid a battle zone between wetness and dryness, with both forces competing for control of the mountain landscape.

The above view was captured as heavy rain was moving into the City of Norton late on Monday, with 1.32″ falling rapidly into the official NWS rain gauge at the Norton Water Plant  ( boosting the July tally to 6.23″ and 2016 to 32.57″ ).

Meanwhile, other places had little rain with just 0.04″ measured in my official rain gauge at Clintwood 1 W ( 3.36″ during July ).

The other story has been the heat.  Official National Weather Service observer Layton Gardner, of UVA-Wise, recorded the first 90 degree day of 2016 on Sunday ( it is listed above as being the 24-hour MAX for the period that ended during the morning of July 25 ).

That marks a Lemon-Aide Day in Wise with it being the first official 90 degree day in more than 4 years, since July 1, 2012.  Hitting 90 degrees in Wise is a big deal since it rarely occurs.

The longest stretch with no 90 degree days in Wise was 13 years, and occurred during the 1967-1979 period when the highest temp observed reached 89 degrees.  The hottest temperature that has ever been observed in Wise reached a sizzling 95 degrees on June 30 in 2012 ( record keeping began in 1955 ).

I recorded the first official 90 degree day in 4 years for Clintwood on Saturday ( July 23 ), with 91 degrees listed as the 24-hour MAX ending during the morning of July 24.

Average July 2016 daily maximums being in the low-mid 80s for Clintwood and Wise.

Higher up in elevation, at the Black Mountain MesoNet site, several days have now managed to break 80 degrees at the 4031 foot level.  The daily average MAX being 75.8 degrees.

*Temperatures atop the High Knob Massif tend to run a tad lower than at the Black Mountain MesoNet, and will be posted in coming months into next summer as data collection increases.

The high-resolution NAM 4 KM Model ( above ) looks like it has caught a bad case of the measles, which is the model’s way of saying that “big downpours are coming…I just don’t know exactly when and where they will strike until storms actually develop.”

Folks in Wise County will just have to keep fingers crossed that the 9.00-10.20″ MAX during the next 10 days will be bogus, as forecast by the GFS Model ( below ), or at the least will not fall all at once!!

The focus through the next few days will be on increasing chances for tropical downpours which, as has been seen during recent days, can drop a lot of water quickly!

My forecast for tropical downpours and possible water problems, first issued back during the weekend, came true and will remain valid through coming days as the air mass becomes even more humid.  

Please stay tuned to NOAA Weather Radio and your favorite media sources for possible watches and warnings-advisories that may be needed.

Mountain Area Forecast ( July 24-26 )

Tropical Downpours & Booming Thunderstorms Will Be Possible At Times From Sunday Through Much Of This Upcoming Week – Some Storms Could Be Strong To Locally Severe In Addition To Dropping Heavy Rain The Could Cause Localized Water Problems

A high moisture content air mass will interact with a stalling boundary to increase coverage of showers & thunderstorms across the Cumberland Mountains through much of this week, especially from Monday ( July 25 ) through the final days of July as a steamy air mass holds across the region ( lower temps but high humidity ).

During this time of year wind shear tends to take a back seat as a severe weather generator, with CAPE ( instability ) and water loading of down-drafts becoming main factors along with slower storm motion that tends to prolong heavy rain, lightning, and any hail over a given location as many pulse up-down and “rain themselves out” over localized places.

Overnight Into Sunday Morning

Partly-mostly clear.  Areas of dense fog ( especially in the northern portions of Wise County and western Dickenson where torrential rain fell Saturday ).  Light winds.  Mild.  Temperatures in the 60s to lower 70s.

Sunday Afternoon

Partly cloudy & continued hot.  A chance of hit-miss showers and downpours in booming thunderstorms.  Humid.  Light winds outside of any storms.  Temperatures varying from middle-upper 70s at highest elevations to the middle 80s to around 90 degrees ( hotter toward Jonesville and the Tri-Cities ).

Sunday Night Into Monday Morning

A chance of showers and downpours in thunderstorms, especially during the evening.  Hazy & humid with areas of dense fog.  Light winds.  Temperatures in the 60s to low 70s.

Monday Afternoon

Partly-mostly cloudy with a good chance of showers and downpours in booming thunderstorms.  Humid.  Light and variable winds 10 mph or less outside any thunderstorms.  Temps varying from low-mid 70s in upper elevations to the mid-upper 80s ( hotter south toward the Great Valley ).

Monday Night Into Tuesday Morning

A chance of showers and downpours in thunderstorms, especially during the evening.  Hazy & humid with areas of dense fog.  Light winds, except W-NW at 5-10 mph on upper elevation mountain ridges.  Temps in the 60s to lower 70s.

Tuesday Afternoon

Partly-mostly cloudy with a good chance of showers and downpours in booming thunderstorms.  Humid.  Light and variable winds 10 mph or less outside any thunderstorms.  Temps varying from low-mid 70s in upper elevations to the mid-upper 80s ( hotter south toward the Great Valley ).

Weather Discussion ( July 23-26+ )

Majestic cumulonimbus and towering cumulus illuminated by sunset on July 23 ( below ).

Booming thunderstorms broke the heat in the Clintwood to Pound corridor on Saturday, with torrential rains falling on Red Onion Mountain into Pound and upper portions of the North Fork of Pound Lake watershed ( 1.00″ to 2.00″+ ).

The rainfall legend below also corresponds to this zoomed terrain map ( above ).

The official temperature reached 90.6 degrees in Clintwood, prior to these thunderstorms, marking the first 90 degree reading of 2016 and the first observed since July 2012.

Temperatures peaked in the mid-upper 80s within middle elevations of central-southern Wise and Dickenson counties.

*Layton Gardner reports that the official July 1-23 MAX has been 87 degrees at the University Of Virginia’s College At Wise ( the average Daily MAX during this period being 82.6 degrees ).

More hit-miss showers & booming thunderstorms will be possible Sunday as heat builds again.  A better coverage of showers and tropical downpours in storms is expected by Monday-Tuesday through the final days of July.

Any given place could be hit or missed on multiple days, making prediction of where storms and heavy rains strike very difficult until activity actually develops on Doppler radar.

A concern for too much rain, amid tropical downpours in a high water content air mass, has returned ( as seen between Clintwood-Pound on Saturday PM of July 23 ) and will remain a threat through the final days of July.

Models will continue to struggle with placement and amounts of the heavy downpours, but the signal is again clear for heavy to potentially excessive rainfall amounts.

The GFS Model has been very aggressive with heavy-excessive rainfall amounts during the upcoming 5-10+ day period.

The latest European Model is showing 2.00″ to 5.00″ basin average totals being possible during the next 10 days ( implying that local amounts could be much higher ).

Rainfall amounts will most certainly vary greatly over short distances ( as seen July 23 ), which makes it hard for any model to resolve ( especially over complex terrain ).

The Bottom Line…Heat continues Sunday but with a trend of increasing humidity and increasing chances for more booming storms and tropical downpours at times through this coming week and the final days of July 2016.  A concern for too much rain in some places will be a threat, as has been the pattern along and north of the Cumberland Mountains this summer.

Stay tuned to NOAA Weather Radio and your favorite media sources for any watches, warnings & advisories which may be issued through coming days.

Mountain Area Forecast ( July 21-23 )

The hottest temperatures of this year will be possible in most places during Thursday-Friday ( July 21-22 ) before increasing humidity-clouds return a chance for showers and downpours in thunderstorms this weekend through next week ( especially in the mountains ).  Use common sense ( slow down, take it easier and never leave pets or children in a vehicle – check on the elderly and those without air conditioning ).

Any thunderstorm developing this weekend into next week could be strong to locally severe with booming thunder and dangerous lightning, gusty winds, and gully washing rains.

Overnight Into Thursday Morning

Mostly clear.  Areas of valley fog.  Light N winds shifting ENE to ESE at generally less than 10 mph along mid-upper elevation mountain ridges-plateaus.  Temperatures from mid-upper 50s to the mid-upper 60s ( except lower 50s in upper elevation valleys above 2700-3000 feet within the High Knob Massif ).

Thursday Afternoon

Mostly sunny.  Hot.  Light NE winds.  Temperatures varying from mid-upper 70s at highest elevations to the mid-upper 80s in middle-low elevations north of the High Knob Massif and Tennessee Valley Divide.  MAXS 90 to 95 degrees lee of the High Knob Massif into the Great Valley.

Thursday Night Into Friday Morning

Mostly clear.  Areas of valley fog.  Light winds, except breezy-gusty along high mountain ridges.  Temps varying from the mid-upper 50s to mid-upper 60s, except 50-55 degrees in higher valleys above 2400-3000 feet.

Friday Afternoon

Partly cloudy.  Hot.  Chance of hit-miss showers or thunderstorms.  Increasing humidity-haze.  Light NW-NNW winds.  Temperatures varying from mid-upper 70s at the highest elevations to mid-upper 80s ( hotter south and southwest toward Jonesville and the Tri-Cities ).

Friday Night Into Saturday Morning

Partly-mostly cloudy.  Chance of a shower or thunderstorm.  Haze with areas of valley fog.  Light winds.  Temperatures varying from upper 50s to lower 60s in cooler valleys to the mid 60s to low 70s ( mildest exposed mid elevation ridges ).

Saturday Afternoon

Partly cloudy.  Continued hot.  A chance of hit-miss showers and downpours in booming thunderstorms.  Generally light winds outside of any storms.  Temperatures varying from mid-upper 70s in upper elevations to the middle to upper 80s ( hotter toward Jonesville and the Tri-Cities ).

A steamy air mass will will support a daily chance for showers and downpours in thunderstorms from Sunday through next week and the final days of this month ( July 24-31 ).

Weather Discussion ( July 19-24 )

Thursday Evening Update

Drier air allowed for a relatively large day-night temp spread during Thursday, with AM MINS in the 50s within mountain valleys and afternoon MAXS in the 80s.

The official temperatures for Clintwood featured a 30 degree temp spread between 57 degrees Thursday AM and 87 degrees in the PM.

I took the above photograph in short-sleeves, but actually felt a little cool by the time I left with a near steady north breeze and temperatures around 70 degrees.

Due to moisture evaporation from the ground & vegetation it is difficult to officially break 90 degrees across most of Wise and Dickenson counties, especially along and north of the High Knob Massif and near Cumberland Gap NHP in Lee County where wetter summer conditions have prevailed.

A couple more days will have a chance to make a run for 90 in the lower-middle elevations, but eventually clouds and an increase in showers-storms will take its toll and hold temperatures back ( as humidity rises to make it steamy ).

Conditions are different to the south, into the Great Valley, where much drier ground has allowed the Tri-Cities to rack up the 90+ degree days during Summer 2016.

No surprise given 19.62″ of total precipitation this year in the Tri-Cities, with 3.71″ during June 1 to July 21, versus more than 31.00″ in the City of Norton ( around 10.00″ during June 1-July 21 ) and around 40.00″ in upper elevations of the High Knob Massif.

Previous Discussion

Thunderstorms that formed above South Fork Gorge and Maple Gap of the High Knob Massif on Tuesday afternoon turned severe as they moved off the high country into Natural Tunnel State Park & parts of the Great Valley.

A nice air mass; although, still somewhat humid & hazy, lingered amid the high country with afternoon temperatures within the lower to middle 70s above 3200 feet in the High Knob Massif.

It is a blessing to have a place where one can photograph Turk’s-cap and Canada ( Lilium canadense ) lilies while listening to the croaks of Northern Ravens ( Corvus corax ) and a couple dozen or more species of Wood Warblers ( along with many more species ).

Temperatures on Wednesday ( July 20 ) varied from mid 70s at highest elevations in the High Knob Massif to the lower to middle 80s in Norton-Wise and Clintwood ( 86 degrees officially at 1560 feet elevation in Clintwood ).

Although stream levels are seasonally low, the woods remained damp when I was out on Tuesday ( July 19 ) with fungi growing in numerous places.  June-July rainfall totals across the High Knob Massif have generally varied from 10.00″ to 13.00″, with around 10.00″ measured at the base in the City of Norton.

Focus is now on the hottest temperatures of 2016 during Thursday-Friday ( July 21-22 ) before increasing humidity levels likely cause increased build-ups of clouds over the mountains this weekend into next week, some of which will develop into showers & booming thunderstorms with gully washing downpours of rain ( as has been the pattern of this summer in the Cumberland Mountains ).

*Thunderstorms that form amid unseasonably hot air typically generate booming thunder ( i.e., dangerous lightning ) and have downpours of gully washing rainfall.  Should clouds and storms not develop in coming days, heating would be more intense and temperatures higher ( even atop the high country ).

The signal for a return of showers & downpours in thunderstorms shows up well on the 51-Member European Ensembles with a retro-gression of the highest 500 MB heights toward the west next week.

Although conditions remain steamy and plenty warm-hot enough, the hottest air eases ( especially in places impacted by more clouds and showers-thunderstorms ).

While remaining warmer than average, the hottest air and largest temperature anomalies retrogress westward and become centered upon the Rockies and Inter-Mountain West and West Coast during next week ( July 26-30 ).

Meanwhile, time will tell if highest elevations can break 80 degrees for the first time this year and if middle elevations, and hollows north of the High Knob Massif, can break the 90 degree mark for the first time this year ( and for the first time officially since back in Summer 2012 ).

Wise has not officially reached 90 degrees since back on July 1, 2012 with MAXIMUM temperatures for recent years including:

Wise National Weather Service Station
Highest Annual Temperature

85 degrees in 2013
84 degrees in 2014
86 degrees in 2015

87 degrees ( so far in 2016 )

Mountain Area Forecast ( July 16-19 )

The Storm Prediction Center Has Issued A Marginal Risk For Severe Thunderstorm Development From  8:00 AM Monday To 8:00 AM Wednesday

Remainder Of Saturday Afternoon

Partly cloudy with hit-miss showers & downpours in thunderstorms.  NNW-NE winds 5-10 mph, with higher gusts.  Temperatures varying from the lower 70s to the lower 80s ( coolest in upper elevations and hotter south toward the Tri-Cities ).

Saturday Night Into Sunday Morning

Chance of a hit-miss evening shower or storm then becoming mostly clear.  Areas of valley fog.  Light SW-W winds along mid-upper elevation mountain ridges.  Temps varying from mid-upper 50s to the mid-upper 60s ( coolest in mountain valleys having little to no fog formation ).

Sunday Afternoon

Partly sunny.  Chance of a hit-miss shower or downpour in a  thunderstorm.  Winds SSE-SSW generally less than 10 mph outside of any storms.  Temperatures varying from the 70s at highest elevations to the low-middle 80s ( warmer south toward the Tri-Cities ).

Sunday Night Into Monday Morning

Partly cloudy.  Chance of a hit-miss shower or storm.  Areas of valley fog.  Wind SSW-WSW 5-15 mph, with higher gusts, on middle-upper elevation mountain ridges.  Temps mostly in the 60s to near 70 degrees ( around 60 degrees in cooler mountain valleys ).

Monday Afternoon

Partly-mostly cloudy.  Chance of showers & downpours in thunderstorms.  SW-W winds 5-10 mph, with some higher gusts along mountain ridges.  Temperatures varying from 70s in upper elevations to the lower-middle 80s ( hotter to the south into the Great Valley and Tri-Cities ).

Monday Night Into Tuesday Morning

Partly-mostly cloudy.  Hazy with areas of fog.  Chance of a shower or thunderstorm.  Winds WSW to WNW 5-10 mph, with higher gusts along mountain ridges.  Humid and mild with temperatures in the 60s to lower 70s.

Development of a coast-to-coast heat wave is expected by late this week into this weekend ( July 21-24 ) with the hottest conditions of the summer season.  Local MAXS will depend upon cloud formation over the mountains and any showers or storms that might be able to form.  Stay tuned for updates on this event.

Weather Discussion ( July 16-19 )

Abundant clouds along with a few showers & downpours in thunderstorms are being observed Saturday ( July 16 ) as a weak boundary approaches the Cumberland Mountains.

A MAX temperature of 82.2 degrees in Clintwood quickly fell back to 69.6 degrees as a thunderstorm, with a brief downpour, passed over the weather station around 4:20 PM Saturday ( July 16 ).

Temperatures have held in the 70s during the day above 2600 feet, especially in locations along and north of the High Knob Massif and Tennessee Valley Divide.

Although temperatures have been plenty warm, true heat has been escaped so far amid July in the mountains with enough rainfall to hold the hottest air at bay.

MAX July 1-15 temperatures were in the 70s to middle 80s  at elevations above 2500 feet, with rainfall totals of 4.00″ to 5.00″+ in the High Knob Massif area.  This included the City of Norton where 4.64″ of rain ( 30.98″ in 2016 ) had been measured through the morning of July 16.

Note how the lack of widespread significant rain, by contrast, has enhanced heating amid the Tri-Cities of northeastern Tennessee, in combination with lower elevations, so far during July ( above ).

In the short-term disturbances riding around the periphery of the hottest air will continue to hold the heat at bay, with the next best chance of organized thunderstorms coming into or close to the area by Monday into Tuesday.

Focus then shifts toward a pattern that will attempt to spread true heat into the mountains by later next week amid a coast-to-coast heat wave.

This has been well forecast far in advance by the European Model, with its 51-Member Ensemble MEAN showing how the heat spreads coast-to-coast by the 6-10 day forecast period of July 22-26.

The magnitude of local heating, as so true of the mountains, will be dependent upon cloud formation and any showers or storms that might develop.  Less clouds and showers = more heat, as does drier ground = more heat ( so places with drier ground relative to other sites will tend to heat up more ).

Stay tuned for later updates.

Mountain Area Forecast ( July 11-15 )

Heavy To Excessive Rainfall Will Be Possible At Times This Week Amid A High Moisture Content Air Mass

The Storm Prediction Center Has Updated For A Slight To Marginal Risk For Severe Thunderstorms Between 8:00 AM Thursday and 8:00 AM Friday ( July 14-15 )

*A Marginal Risk is currently forecast to continue through Friday into early Saturday from the Cumberland Mountains southward.

A heavy to excessive rainfall potential will continue to be a weather concern in coming days, along with the potential for strong-severe thunderstorms by late week ( July 14-15 ).  A front is likely to stall across the area by this weekend to continue the daily chance for showers & thunderstorms.

**Depending upon where the boundary stalls, an increased risk for heavy-excessive rainfall may arise by late Friday into Saturday as very light winds develop aloft for slow storm motion on anything that develops.

Overnight Into Tuesday Morning

Partly to mostly cloudy with a chance of hit-miss showers and thunderstorms.  Areas of dense fog.  SW to WSW winds 5-10 mph on mid-upper elevation mountain ridges.  Temps in the upper 50s to mid-upper 60s ( mildest along exposed middle-upper elevation ridges and plateaus ).

Tuesday Afternoon

Showers & downpours in thunderstorms becoming likely.  SW winds 5-15 mph, with higher gusts.  Temperatures in the 60s to lower 70s in upper elevations to the mid-upper 70s ( warmer south toward the Tri-Cities ).

Tuesday Night Into Wednesday Morning

Chance of a shower or thunderstorm.  Areas of dense fog.  Winds WSW-WNW at 5-15 mph, with higher gusts, along middle-upper elevation mountain ridges.  Temperatures widespread in the 60s.

Wednesday Afternoon

Chance of showers & downpours in thunderstorms.  Humid.  Winds SW-W at 5-10 mph, with higher gusts.  Temperatures varying from 70s in upper elevations to the low-middle 80s  ( warmer south toward the Tri-Cities ).

Wednesday Night Into Thursday Morning

Chance of showers & thunderstorms.  Humid & hazy with areas of dense fog.  SW-W winds 5-15 mph along mid-upper elevation mountain ridges.  Temps in the 60s to lower 70s.

Thursday Afternoon

Showers & thunderstorms likely.  Some storms may be strong to severe. Winds SW-WSW 5-10 mph, with higher gusts.  Warm & humid with temperatures varying from 70s in upper elevations to the 80s across low-middle elevations.

Thursday Night Into Friday Morning

A chance of showers & thunderstorms, especially during the early evening.  Areas of dense fog.  Winds SW-W 5-10 mph on mid-upper elevation mountain ridges & plateaus.  Mild with temperatures in the 60s to around 70 degrees.

Weather Discussion ( July 9-14 )

Thursday Overnight Notes

For days now models have been showing a very unstable air mass developing across the mountain region on Thursday, with high CAPE and low LI values combined with a bounty of moisture for potential water loading of downdrafts.

Debris clouds from upstream convection or early development of clouds-storms over the mountains could alter this by keeping the air cooler and more stable.  Something that will have to be tracked through Thursday into Friday to see how it unfolds.

It is hard to conceive that at least a few storms will not go severe, or be very strong, amid this type of air mass.  The main thing that is needed will be a trigger to initiate convection, with the terrain plus outflow boundaries from activity to the northwest & north as well as an actual surface boundary all being potential low-level triggers for convective firing.

Although downpours will certainly occur with any storms Thursday into Friday, the late Friday into Saturday period is currently catching my eye as parameters for local areas of heavy-excessive rainfall will increase.

Mean winds aloft drop under 10 knots by later Friday into Saturday within the surface-8 km layer as air remains very moisture ( 1.50″ to 2.00″ of precipitable water ).

Stay tuned to NOAA Weather Radio and your favorite media sources for possible watches and/or warnings that may be needed during the Thursday-Saturday period of July 14-16.

Previous Discussion

Gorgeous weekend conditions graced the Cumberland Mountains with day-time MAXS in the 70s to lower 80s coupled with nights in the 50s and 60s.

I measured 4.10″ of rain at Big Cherry Lake Dam on Saturday, which had fallen during the previous week, amid frequent showers and downpours in thunderstorms.

*The lake level was still below the Dam spillway with 127+ Million gallons of water having been released from the lake during June to augment flow on the Powell River ( allowing room for the lake to still hold back run-off ).

Temperatures at highest elevations barely broke 70 degrees on Saturday & Sunday ( July 9-10 ), with 71.8 degrees being the weekend MAX observed at 4031 feet on Black Mountain.

Although several trees were blown down in the area the damage was spotty in nature and not widespread, as was  the case for folks lee of the mountains in the Great Valley.

Some gully washing downpours have been observed Monday, with a much better coverage of showers & downpours in thunderstorms  expected to develop Tuesday and periodically there-after during the remainder of this week-weekend and likely into next week.

Like last week, models continue to vary from run to run on where and how much rain will fall.  A repetitive pattern in a high moisture content air mass suggests some places will receive heavy to locally excessive rainfall.

The pattern during Summer 2016 ( June-July ) has been very consistent, especially since mid-late June, with a 500 MB air flow pattern very close to what MEAN 51-Member European Ensembles are forecasting during the next 10 days.

This being especially true if combining DAYS 1-5 with DAYS 6-10, such that the MEAN is very close to the Observed Composite MEAN graphic illustrated above for the June 22 to July 9 period.

The notable difference being a vertical expansion of the atmosphere across the nation as we enter what is often, climatologically at least, the hottest part of summer.

The hottest conditions so far during Summer 2016 ( above ) have been centered over the central-western USA, with a general W-WNW-NW flow into this region.

This type of pattern is forecast to continue during the next 10 days, with tendencies for increasing NW flow during the 5-10+ day period.  This implies that more organized clusters of thunderstorms will become likely, some with a damaging wind potential to accompany heavy rainfall during the mid-late July period.

NOTE I use the MEAN of the 51-Member European Ensembles since they are BY FAR ( and have been ) the most stable outward in time, and nothing suggest’s that they will not continue to be.

Part of, or superimposed upon, the above pattern has been developing drought across the southeastern USA into the Tennessee Valley and southern Appalachians.

*Differences being locally exemplified by nearly as much rain in the High Knob Massif since May 1 ( beginning of the convective season ) as observed in the Tri-Cities during the entire year.

The Bottom Line…Although there are always waxes and wanes that force daily weather changes, the big picture or synoptic-scale pattern remains consistent this summer and suggests that more of the same is upcoming for the mountain region during mid-late July.  This being superimposed upon drought that is trying to spread across the Deep South into parts of the Mountain Empire, as much wetter conditions and cooler mean temperatures continue from the local mountains ( High Knob Massif ) northward.

Meso-scale Notes On Monday – July 11, 2016

The High Knob Massif has acted as a cloud generation zone for booming thunderstorms, with gully washing rain, that have been over the adjacent Tennessee Valley Divide ( along the border of Wise and Dickenson counties ).

Note how the clouds in these individual frames can be seen extending back to the summit region and heads of the High Knob Lake, Big Cherry Lake, and Norton Reservoir’s basins.

An example of how wetness over the massif feeds into the over-lying atmosphere to develop towering clouds that go along with the atmospheric steering flow field to rain upon adjacent locations ( it happens all the time, but this is a nice current example that is visually obvious ).

*Total precipitation for 2016 has now reached around 40.00″ in the High Knob Massif versus less than 20.00″ for portions of the Great Valley only 30-35 or so air miles toward the south.

Any doubts about the massif impacting air flow can be eradicated by noting these nice lenticular mountain waves forming amid the wake zone ( fishtails on some above and stacked below ).

A really nice NASA visible showing clouds literally arising from the crest zone of the High Knob Massif and streaming across the southern portions of Dickenson and Buchanan counties into the extreme southern portion of West Virginia.

Mountain Area Forecast ( July 9-11 )

ALERT For Heavy To Excessive Rainfall At Times Into Next Week Amid A Persistence Pattern

A heavy to excessive rainfall potential with the possibility of dangerous flash flooding will continue to be a weather concern, especially from the Cumberland Mountains north and west, in coming days as waves of showers & downpours in thunderstorms periodically move across the region.

While many dry hours will occur, with a break from active storm clusters for much of this weekend, the storm pattern renews into next week.  Accumulative rain amounts over time will saturate the ground and make later activity more likely to cause water problems ( especially with any training or back-building of convection which occurs ).

*A general 2.00″ to 5.00″ of rain was observed across the mountain area during the July 3-8 period.

These statements are based on recognition of a repetitive synoptic-scale weather pattern and recent ( antecedent ) conditions producing numerous flash floods in the region.

Overnight Into Saturday Morning

A chance of showers & downpours in thunderstorms, especially toward morning.  Areas of dense valley fog.  SW to W winds 5-15 mph on mountain ridges & plateaus below 2700 feet.  WSW to WNW winds 10-20 mph, with higher gusts, on upper elevation mountain ridges.  Humid with temps mainly in the 60s.

Saturday Afternoon

Becoming partly sunny. Chance of a hit-miss shower or thunderstorm.  WNW winds 5-15 mph, with higher gusts.  Temperatures varying from 70s across upper elevations to the low-mid 80s ( hotter south toward the Tri-Cities ).

Saturday Night Into Sunday Morning

Partly to mostly clear ( some high clouds ).  Areas of dense valley fog.  W-NW winds 5-15 mph along upper elevation mountain ridges.  Cooler with temperatures varying from 50s in cooler mountain valleys to the mid-upper 60s.

Sunday Afternoon

Partly-mostly sunny. Chance of a shower or thunderstorm.  Light WSW to WNW winds mainly less than 10 mph.  Temps varying from 70s in upper elevations to the low-middle 80s ( hotter toward the Tri-Cities ).

Sunday Night Into Monday Morning

Partly to mostly clear.  Areas of dense valley fog.  Light winds.  Temepratures varying from mid-upper 50s to the mid-upper 60s ( coolest in mountain valleys ).

Clusters of showers & downpours in thunderstorms are expected to return by Monday into Monday Night and to continue periodically through most of next week.

Weather Discussion ( July 8-11 )

A vigorous storm line spread heavy rain, strong winds, and vivid lightning across the mountains Friday afternoon.

An outflow boundary was accompanied by strong and gusty winds in advance of the main storm line, part of a low-end Derecho that crossed the Ohio Valley, Appalachians-northern Tennessee Valley, producing torrential downpours of rain in Norton-Wise by 5:00 PM ( July 8 ) and local wind damage that increased in coverage lee of the Cumberlands into the Great Valley.

Thunderstorms began exploding across Kentucky into western parts of West Virginia during early afternoon, amid a steamy atmosphere loaded with water.

Over-shooting tops developed on some of the stronger storms, with Severe Thunderstorm Warning’s and Flood Advisories being issued for many counties from eastern Kentucky, western West Virginia and southwestern Virginia into the Great Valley.

Power outages were widespread across the region with numerous counties reporting current outages, on just the AEP Network, as of 11:03 PM Friday ( July 8 ).

Rainfall totals varied from around 0.50″ to between 1.00″-2.00″ as the storm cluster ( MCS ) passed.

*Local rainfall totals during July 3-8 have reached between 4.00″ and 5.00″, thus a concern for flooding will continue as storms increase in coverage into next week with more active clusters expected to rumble across the mountain landscape.

Meanwhile, it is hoped that much of this weekend will remain free of showers & thunderstorms after Saturday morning to mid-day ( behind a frontal passage ).

Mountain Area Forecast ( July 7-9 )

ALERT For Heavy To Excessive Rainfall At Times From This Week Into Next Week Amid A Persistence Pattern

Severe Thunderstorm Watch In Effect Until 9:00 PM

The Storm Prediction Center Has Issued A Enhanced Risk For Severe Thunderstorms Through Friday PM Into Friday Night – Main Severe Risk Is Wind Damage

A heavy to excessive rainfall potential with the possibility of dangerous flash flooding will continue to be a weather concern, especially from the Cumberland Mountains north and west, in coming days as waves of showers & downpours in thunderstorms periodically move across the region.

While many dry hours will occur, with a break from active storm clusters for at least part of this weekend, the storm pattern renews into next week.  Accumulative rain amounts over time will saturate the ground and make later activity more likely to cause water problems ( especially with any training or back-building of convection which occurs ).

These statements are based on recognition of a repetitive synoptic-scale weather pattern and recent ( antecedent ) conditions producing numerous flash floods in the region.  

Remainder Of Thursday Afternoon

Partly to mostly cloudy with scattered showers.  Chance of thunder.  Areas of dense fog across upper elevations.  Winds W-NW 5-15 mph, with higher gusts.  Temperatures varying in the 60s to lower-middle 70s ( warmer to the south into the Great Valley and Tri-Cities ).

Thursday Night Into Friday Morning

A chance of showers & downpours in thunderstorms.  Winds SW-W 5-15 mph on mountain ridges-plateaus below 2700 ft. WSW-WNW winds 10-20 mph, with higher gusts, on upper elevation mountain ridges.  Humid with temperatures in the 60s to around 70 degrees.

Friday Afternoon

A chance of showers & downpours in thunderstorms.  Some storms could be strong to severe with damaging winds and hail.  Winds SW to W 5-15 mph, with higher gusts.  Humid & hazy with temperatures varying from 70s to lower-middle 80s ( warmer south toward the TRI ).

Friday Night Into Saturday Morning

A chance of showers & downpours in thunderstorms.  Some storms could be strong to severe with damaging winds and hail.  SW to W winds 5-15 mph on mountain ridges-plateaus below 2700 feet.  WSW-WNW winds 10-20 mph, with higher gusts, along upper elevation mountain ridges.  Humid with temperatures in the 60s to lower 70s.

Weather Discussion ( July 5-9 )

Early Friday Afternoon

A dangerous severe thunderstorm-heavy rainfall setting is taking shape for the Mountain Area this afternoon into this evening ( Friday July 8 ).

Wind damage and power outages will be a significant threat along with any storms that train or back-build to generate very heavy rainfall ( even weak looking showers on Doppler have had downpours today as the air mass is water loaded ).

Warnings will be likely for some of this activity, so please remain alert to changing weather conditions.

Previous Discussion

Some majestic cloud formations have been observed through Thursday as abundant moisture and W-NW flow have combined to keep low clouds ( dense fog ) and many showers going across the High Knob Massif area.

Rainfall totals during this first week of July ( during the past several days ) have now reached around 3.00″ or more in upper elevations of the High Knob Massif, with widespread 1.50″ to 2.50″ amounts being observed across surrounding locations within Wise and Dickenson counties.

*Southern Kentucky and portions of middle Tennessee being the most recent targets for flooding rains.

Temperatures Thursday have remained in the 60s across mid-upper elevations above 2600 feet, with lower-mid 70s at low-middle elevations along and north of the High Knob Massif and Tennessee Valley Divide.

As of 4:42 PM ( July 7 ) the official MAX had reached 74.6 degrees at Clintwood 1 W in the Russell Fork Basin ( elevation 1560 feet ).

*The official MAX in Clintwood ended up reaching 76.1 degrees ( the July rainfall total climbing to 1.65″ ).

Focus now shifts toward additional storm clusters that are being forecast to develop overnight into Friday in advance of an approaching upper trough and surface front.

While a slight risk for severe thunderstorm development has been issued for the period from 8 AM Friday to 8 AM Saturday, recent runs of the HRRR and RPM models are showing overnight storm development.

Time will soon tell if these models are correct in this overnight storm development, with local 1.00″ to 4.00″+ rainfall amounts predicted.

*Remember is it difficult for models to handle convection, such that placement and timing of storms and MAX rainfall amounts prior to actual storm development is subject to change.

The threat for additional strong-severe thunderstorms in advance of a surface front must be respected by later Friday into Friday evening.

Please stay tuned to NOAA Weather Radio and your favorite media sources for possible watches and/or warning that may be needed.

Mountain Area Forecast ( July 5-7 )

ALERT For Heavy To Excessive Rainfall At Times From This Week Into Next Week Amid A Persistence Pattern

A heavy-excessive rainfall potential, with the possibility of dangerous flash flooding, will be the main weather concern for locations from the Cumberland Mountains northward in coming days as waves of showers and downpours in storms move across the region.  While many dry hours will occur, accumulative amounts will saturate the ground and make subsequent activity more likely to cause water problems.

It might seem unusual to issue a forecast statement as above, but in this case it is based upon recognition of a repetitive synoptic-scale pattern & recent ( antecedent ) conditions producing numerous flash floods across the region.  It is meant to raise awareness-alert levels that conditions favorable for flash flood generation will be present during a prolonged period of time.

Overnight Into Tuesday Morning

Intervals of showers & downpours in thunderstorms.  Areas of fog.  SSW-SW winds 5 to 15 mph, with higher gusts, along mid-upper elevation mountain ridges & plateaus.  Warm and humid with temps varying in the 60s to lower 70s.

Tuesday Afternoon

Periods of showers & downpours in thunderstorms.  Some storms could be strong to locally severe.  Humid  SW-WSW winds 5-15 mph, with higher gusts.  Temperatures varying in the 70s to lower 80s ( hotter south toward the Tri-Cities ).

Tuesday Night Into Wednesday Morning

A chance of showers & thunderstorms; otherwise, mostly cloudy, hazy and mild.  Areas of fog.  Winds SW-W 5-15 mph along mid-upper elevation mountain ridges and plateaus.  Temperatures widespread in the 60s to near 70 degrees.

Wednesday Afternoon

Hazy & humid.  A chance of showers & downpours in thunderstorms.  Winds SSW-SW 5-10 mph, with higher gusts.  Temperatures in the 70s to low-mid 80s ( hotter south toward the Tri-Cities ).

Wednesday Night Into Thursday Morning

Showers & downpours in thunderstorms.  Winds SW-W 10-20 mph, with higher gusts, mid-upper elevation mountain ridges.  Humid.  Temperatures in the 60s to lower 70s.

Weather Discussion ( July 4-7 )

Reference June 2016 Climate Data for rainfall totals ( more data to come soon ) as well as the new May 2016 Climate Data section.

Strong to severe thunderstorms blasted into the mountains late Monday afternoon with wind damage & power outages in numerous places to accompany downpours of rain.

Rainfall totals topped 1.00″ in Big Cherry Lake basin of the High Knob Massif as the storms developed and moved over into the Clinch and Holston river valleys.

More downpours of rain are pounding on roof-tops in Clintwood at 1:30 AM Tuesday as new development is propagating northeast from middle Tennessee and the southern portion of Kentucky.

For days now all models have been predicting heavy to excessive rainfall amounts through coming days, with placement & timing of the heaviest rain being the main uncertainty, with each model run being different with  respect to where the flooding rains occur.

The signal; however, is clear.  Heavy to excessive rains are likely to hit in places across the region this week into next week ( European Ensembles continue the pattern into next week ) as a high precipitable air mass hangs over the region.

*Some may think MAX totals of 8″ to 12″ are bogus; however, such amounts were being shown before the West Virginia flood event!

In the short-term, models suggest overnight into Tuesday and late Wednesday into Thursday as periods to watch for heavy to locally excessive rain amounts ( this does not mean that activity will not occur in between these waves ).

Due to the nature of convection, and the way it can alter the atmosphere, it will be necessary to update the forecast and this potential for heavy-excessive rainfall through coming days.  The big picture pattern; however, is clear with blazing heat to the south & southwest of the mountain area acting to generate and guide frequent clusters of showers and storms around its periphery into the Appalachians.

The Bottom Line…Now is the time, before the next flood, to be aware that another event or events are possible to likely in portions of the region this week into next week.  While there will likely be many dry hours, the accumulative nature of downpours over time will create the problem ( especially in locales having had 5.00″ or more of June rainfall and 10.00″+ of May-June rain ).

*Any place can flood if too much rain falls too fast, but antecedent rainfall amounts are important to look at with respect to where heavy rain could saturate the ground quicker ( i.e., it will take more rain to cause flooding in locations that were dry during June versus locations which were wet ).