Partly cloudy & hazy. Humid. Areas of dense valley fog. Light southerly winds along mid-upper elevation ridges. Temps in the 60s to around 70 degrees.
Sunday Afternoon
Partly sunny. Hazy & humid. Chance of hit-miss showers and downpours in thunderstorms. Winds becoming E-NE at 5-10 mph. Temperatures varying from middle to upper 70s in highest elevations to mid-upper 80s ( hotter southward into the Great Valley ).
Sunday Night Into Monday Morning
Chance of hit-miss evening showers-storms; otherwise, partly cloudy. Areas of dense fog. E-SE winds 5-10 mph along mid to upper elevation mountain ridges. Temps varying from upper 50s to the upper 60s.
Monday Afternoon
Partly cloudy. Chance of hit-miss showers-thunderstorms. Winds ENE to NE 5-10 mph, with some higher gusts. Temps varying from low-mid 70s in upper elevations to the lower-middle 80s ( hotter south into the Great Valley ).
Monday Night Into Tuesday
Evening thunderstorms diminishing. Partly cloudy & humid. Areas of dense fog. Light E-NE winds along mid-upper elevation ridges. Temperatures in the 60s to around 70 degrees.
Tuesday Afternoon
Partly cloudy. Chance of hit-miss showers-thunderstorms. Winds E to NE 3-10 mph. Temperatures varying from mid-upper 70s in upper elevations to mid-upper 80s ( hotter south into the Great Valley ).
Tuesday Night Into Wednesday Morning
Chance of hit-miss showers & downpours in thunderstorms. Humid. Areas of fog. Light & variable winds. Temps in the 60s to around 70 degrees.
Weather Discussion ( Final Days )
Late summer heat and humidity helped trigger some booming storms across the mountain area Monday, in hit or miss manner as forecast, with downpours and gusty winds.
Clouds Tower Above Cumberland In Late Summer Heat
Rainfall totals locally topped 0.50″ in just 15-20 minutes in places that got hit hardest with downpours ( e.g., Big Cherry Lake Basin and along Pine Mountain from Breaks Interstate Park southwest toward Pound Gap to note a couple areas ).
The same pattern holds during Tuesday-Wednesday before a cold front arrives Thursday, with cooler and much less humid air again taking control Friday into the Labor Day Holiday Weekend ( beyond that sinking air in wake of passing tropical systems may rebuild the heat ridge ).
Model Spaghetti Tracks On Pre-Hermine Development
Models have finally come into general agreement on the likely formation of former Invest 99L, now Tropical Depression 9, with a movement across northern Florida and back into the Atlantic being the one currently favored.
National Hurricane Center 5-Day Track Forecast For TD9
It is not impossible, of course, that TD8 could beat TD9 to the Hermine name as it briefly intensifies over the Gulf Stream approaching the North Carolina Outer Banks.
National Hurricane Center 5-Day Forecast Track For TD8
Sinking air in the wake of these, by late in the weekend-early next week, will help rebuild heights to the west and likely allow the TRI to add a few more 90s that could help them reach the record for the most 90-degree days ever officially observed in the Tri-Cities.
Shorter days and longer nights will eventually take its toll on summer heat, especially into mid-late September when most years feature significant autumn color changes amid upper elevations of the High Knob Massif ( above 2700-3000 feet ). I, for one, greatly look forward to this color season!
Previous Discussion
The final days of August means it is also the final days for Meteorological Summer 2016. Many will say good riddance given the nearly relentless humidity in the mountains and heat+humidity in the Great Appalachian Valley.
August 27 Temperature-RH at NWS Station In Clintwood
August 27 ( Saturday ) was one of the hottest days of the entire summer ( and the hottest day in August ) within the Cumberland Mountains, with the above temps being recorded in Clintwood between 6:40 AM and 6:40 PM.
The 89.4 degrees PM MAX combined with a muggy 66 degree dewpoint reading ( 48% relative humidity ) to generate a 93 degree Heat Index.
Doppler Radar Rainfall Estimate For August 27, 2016
A few showers and downpours in thunderstorms managed to develop, with some of the heaviest action just southwest of Cumberland Gap. More downpours fell along Guest River Gorge, close to ( if not over ) the rain gauge of Jerry Rose where he’d already measured more than 7.00″ in August.
Most places remained dry.
NAM 12 KM Model Total Rainfall Forecast Next 3-Days
The same pattern holds through the next several days, with a little more cloud coverage over the mountains and a little better coverage of hit or miss showers-storms. Note that emphasis continues to be on hit-miss activity that fights against sinking air aloft to develop amid heat-instability.
Meanwhile, the saga of Invest 99L continues!
Model Spaghetti Tracks For Invest 99L
While possible tracks ( above ) are spread about as wide as they can get, the spread in intensity forecasts ( below ) are perhaps even more impressive with variations from a CAT 4 to not being more than a depression ( at best ).
Model Spaghetti Intensity Forecast For Invest 99L
Even the typically dependable European Model has had large run-to-run variations, and large differences among it’s ensembles. Stay tuned!
