*Showers & downpours in thunderstorms will continue at times, amid a humid air mass, into Tuesday Night.
Heavy to locally excessive rain amounts will remain possible in advance of a strong autumn-like cold front expected to arrive by late Tuesday.
NOAA’s Storm Prediction Center has issued a marginal risk of severe thunderstorm development along and in advance of this cold front.
*Cloud bases will lower and the air will turn notably cooler on northerly winds through Wednesday, with lingering showers possible in advance of a secondary dewpoint boundary that ushers in an early autumn-like air mass late Wednesday into Thursday.
An early autumn-like air mass will drop temperatures into the 40s to middle 50s within locations along & north of the High Knob Massif-Tennessee Valley Divide by Thursday AM. Even cooler air may be felt in colder mountain valleys by Friday morning ( August 24 ). Stay tuned for updates.
*The cooler, drier break will be temporary with a return of humid air and a trend toward above average temperatures by next weekend into the final days of August 2018.
Overnight Into Monday Morning
Partly-mostly cloudy. Muggy. Areas of dense fog. A chance of showers & thunderstorms. Locally downpours possible. Light SSE-SSW winds. Temperatures in the 60s to low 70s.
Monday Morning Through The Afternoon
Muggy & warm with a chance of showers & downpours in thunderstorms. Locally heavy rain possible. Light S-SW winds. Temperatures varying from upper 60s-low 70s in upper elevations to the upper 70s to lower 80s ( warmer south into the Great Valley ).
Monday Night Into Tuesday Morning
Mostly cloudy. Becoming breezy to windy. Chance of showers & thunderstorms. Local downpours possible. Winds S-SSW at 5-15 mph, with higher gusts, on mountain ridges-plateaus below 2700 feet. Winds SW 10-20 mph, with higher gusts, on mountain ridges above 2700 feet. Muggy with temperatures in the 60s to lower 70s.
Tuesday Morning Through The Afternoon
Showers & thunderstorms becoming likely. A few storms could be strong to severe. Local downpours. SW winds 5-15 mph, with higher gusts. Temperatures varying from upper 60s to the upper 70s.
Tuesday Evening Into Wednesday Morning
Showers & thunderstorms likely into the evening, then a chance of showers. A few storms could be strong-severe early with downpours. SW winds shifting W-WNW at 5-15 mph, with higher gusts into morning. Temps falling into the upper 50s to middle 60s.
Wednesday Morning Through The Afternoon
Mostly cloudy with a chance of showers. Low cloud bases at upper elevations, with dense fog into mid-morning to early afternoon at high elevations. Winds NW at 5-15 mph with some higher gusts. Temperatures varying from lower 60s to the low-mid 70s ( warmer south into the Great Valley ).
Wednesday Night Into Thursday Morning
Partly-mostly cloudy early, then decreasing clouds with areas of fog. NW-NE winds diminishing to 5-10 mph, with higher gusts, along mid-upper elevation mountain ridges. Temperatures dropping into the 40s to middle 50s.
Thursday Afternoon
Sunny. Very pleasant. Blue skies. Light N-NE winds. Temperatures varying from lower-middle 60s in upper elevations to the lower 70s.
Thursday Night Into Friday Morning
Clear and unseasonably cool with a large vertical temp spread developing between the colder valleys and milder mountain ridges-exposed plateaus. Winds becoming SE to SSE at 5-10 mph, with higher gusts, on mid-upper elevation mountain ridges. Temperatures varying from upper 30s to lower 40s in colder valleys at upper elevations to the mid 40s to low-mid 50s ( mildest on middle elevation ridges ). Areas of dense river valley fog.
Weather Discussion ( Changes )
With the 12th Annual High Knob Naturalist Rally now just over 1 month away, it is time for a nip to be felt amid air of the high country. Yeah, to less humid air!
September 29, 2018 at High Knob Lake Recreation Area
Featuring the most mountain-top lakes of any mountain in the southern-central Appalachians, this year’s 12th Annual Naturalist Rally will be held at 3500+ feet above mean sea level where the air is always cooler in the high country.
USDA Forest Service – High Knob Lake Recreation Area – Summer 2018
Meanwhile, the relentless stretch of muggy air continues for a little while longer until the first autumn-like cold front ushers in a temporary break by mid-late week.
High Knob Massif Webcam – University Of Virginia’s College At Wise
A refreshing and much cooler air mass will temporarily bring a dramatic change to the mountain area during the August 22-23 period into Friday AM of August 24.
European Model 850 MB Temp Forecast At 8 AM August 23, 2018
The middle range trend will be for humid air and above average temperatures to return during the final days of August 2018.
European 51-Member Ensemble Mean 500 MB Height Anomalies: Days 6-10
NOTE: The 5.24″ of rain measured in Clintwood during August 1-19 pushed the annual total to 46.03″ ( 14.45″ above the 1981 to 2010 average for this point in a year ). The January 1-August 19 total being near the long-term annual average for Clintwood.
NWS Precipitation Analysis – Percent of Normal – During Past 90-Days
*Although a general 47.00″ to 57.00″ of precipitation have fallen in the City of Norton-High Knob Massif area so far this year, the actual annual departure is generally only near to a little above average. This is due to hit-miss summer thunderstorms and local wet feedbacks, superimposed upon the larger-scale weather pattern, which have allowed certain sites and corridors ( e.g., northern Virginia into Pennsylvania ) to receive above to much above average summer rainfall across the eastern USA ( versus nearby locations with near average summer rains ).
