Mostly cloudy. Low cloud bases across high terrain with dense fog. Light & variable winds. Temperatures varying from the 40s to lower 50s.
Friday Afternoon
Partly-mostly cloudy. Small chance of showers-sprinkles. Light SSE-SSW winds. Temperatures varying from upper 50s to lower 60s in upper elevations to the upper 60s to lower 70s.
Friday Night Into Saturday Morning
Mostly cloudy. Small chance of a shower-sprinkle. Winds SSE-SW at 5-10 mph, with higher gusts, along mid-upper elevation mountain ridges-plateaus. Temperatures from the 40s in coolest valleys to the lower-middle 50s.
Saturday Afternoon
Becoming partly cloudy. Light SSE-S winds, except 5-10 mph with some higher gusts at highest elevations. Temps varying from low-mid 60s in upper elevations to the lower to middle 70s.
Saturday Night Into Sunday Morning
Partly-mostly clear. Areas of valley fog. Winds S to SW at 5-15 mph, with higher gusts, along middle-upper elevation mountain ridges. Temperatures varying from 40s in cooler mountain valleys to the lower-middle 50s.
Sunday Afternoon
Partly cloudy. Light SSW-SW winds generally less than 10 mph. Mild. Temperatures varying from 60s in the upper elevations to the lower-middle 70s.
Weather Discussion ( Mild Pattern )
Some spectacular autumn color has developed in mid-upper elevations of the High Knob Massif, with this weekend thru next week currently expected to offer some of the best color as the peak approaches.
A major reason color is so dependably spectacular in the massif year after year is due to a combination of factors. Endemic, rich northern hardwoods within a mixed-mesophytic forest growing atop both calcareous and clastic stratas amid the wettest area in Virginia ( on average over the long-term ) are driving forces that are superimposed upon a sprawling mass of elevated terrain full of high basins ( wetland valleys, lakes, coves ) & complex terrain.
Autumn Color In Upper Elevations of High Knob Massif – October 12, 2016
Although behind schedule, in general, a significant advance in color changes have been observed during the past week amid seasonally cool conditions and abundant sunshine.
Autumn Color In High Valleys of Big Cherry Basin – October 12, 2016
The MEAN temperature observed during October 1-12 within high valleys of Big Cherry Lake basin was 52.1 degrees ( the average of sensor locations ), varying from the lower 60s by day to lower 40s at night ( 30s being observed during October 9-12 ).
October 1-12 Conditions Observed In The Tri-Cities
It is easier to understand the observed differences in color changes when one compares this to the Tri-Cities, amid the Great Valley, where the October 1-12 mean was 61.7 degrees or approximately 10 degrees warmer than local high basins.
The coldest October on record in the Tri-Cities had a MEAN temp of 50.1 degrees in 1988 ( the average is 56.3 degrees ). So conditions recorded in high valleys of Big Cherry Lake during October 1-12 this year would be considered MUCH below average for the TRI.
Autumn In Crest Zone of High Knob Massif – October 12, 2016
Although decreases in sunlight along with cooler conditions trigger autumn colorations, it is important to note that its not only the colder nights but also the much cooler days.
Black Mountain MesoNET for October 1-12, 2016
The highest temperature observed during the October 1-12 period at the MesoNET site atop Black Mountain ( 4031 feet ) has been 69 degrees, the same as recorded in high valleys of Big Cherry Lake basin ( one sensor location there reaching just 68 degrees ).
High valleys, which are plentiful in the High Knob Massif, tend to have lower MEAN temperatures than might be expected due not only to much colder nights ( than are observed along high ridges when radiation rules over advection ) but also to these cooler daytime temps.
So the best, brightest and most advanced color typically begins developing first along the high basins where cold air drainage occurs at night and days are relatively cool due to elevation in combination with exposure. In most autumns color begins to develop in mid-September, with significant colorations often observed by late September-early October.
Autumn 2016, by contrast, did not see significant color changes begin until early-mid October ( 1-2 weeks later than typical ).
European 51-Member Ensemble MEAN 500 MB Height Anomaly – 8 AM Oct 20
Looking ahead, a mostly dry and mild pattern rules into next week when there is increasing evidence that a large storm system ( of some form ) will develop across the eastern USA.
The MEAN of the 51-Member European Ensembles have in recent days been showing a potential phasing event between a tropical cyclone and a mid-latitude upper air trough which would lead to an orographic forcing episode along the Appalachians.
European 51-Member Ensemble MEAN 500 MB Height Anomaly – 8 AM Oct 21
Needlessly to say, IF that occurred it would be a major precipitation maker for the Mountain Empire. However, it remains too far out in time to know exactly what will occur.
The latest 00z run of the operational European Model coming out as I write now continues to also show such an event. Every run that continues to replicate this will increase the odds of a major event that could again be a headline making storm system. It should be stressed again, of course, that its too early to be sure.
Due to changes at high latitudes, with building heights near Greenland and in the Gulf of Alaska next week, it does appear likely that much cooler ( colder ) air will arrive in 7-10 days. Certainly that increases the odds that there could indeed be cyclogenesis…BUT will that occur in such a position as to give much needed rainfall to those places that need it along the mountains while sparing flood ravaged locations to the east?
