My Forecast For Today ( January 15 )

Wind Chill Factors Will Continue To Be Felt Overnight Into This Morning Across Mid-Upper Elevation Mountain Ridges and Plateaus With Strong & Gusty SSW-SW Winds.

*Wind chills will become more intense once again into Saturday, and especially during Sunday-Monday with arrival of the coldest air mass of this 2015-16 season to date.

Overnight Into This Morning

Increasing high clouds overnight.  Continued gusty across mid-upper elevation mountain ridges and plateaus.  S to SW winds 5 to 15 mph, with higher gusts along middle elevation mountain ridges & plateaus below 2700 feet. SSW-SW winds 15 to 25 mph, with higher gusts, on upper elevation ridges above 2700 feet.  Substantial vertical temperature spread developing from MINS of 17 to 23 degrees in valleys with calm winds to upper 30s-lower 40s on exposed middle to upper elevation plateaus and ridges.  Wind chill factors mostly in the 20s and 30s ( coldest at highest elevations ).

This Afternoon

Cloudy.  A period of rain developing, especially along and eastward of the VA-KY stateline.  Winds SSE-S at 5-15 mph, with higher gusts, below 2700 feet.  S-SW winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures mostly in the 40s.  Wind chills in lower 30s to lower 40s ( chilliest across upper elevations ).

Tonight Into Saturday Morning

Rain showers redeveloping.  Turning colder overnight with a chance of rain showers changing to snow showers at mid-upper elevations.  Little snow accumulation at the highest elevations.  S-SW winds shifting W-WNW overnight at 5-15 mph, with higher gusts, below 2700 feet.  Winds becoming W-WNW at 10-20 mph, with higher gusts, above 2700 feet.  Temperatures dropping into 20s to lower 30s by morning, except upper 10s to around 20 degrees at the High Knob Lookout.  Wind chills dropping into 10s & 20s, with some single digits at highest elevations by morning.

 

My Weather Discussion ( January 14-15 )

A notable vertical temperature spread greeted January 14 with lower to middle 10s in mountain valleys verses middle 20s to middle 30s on exposed mountain ridges and plateaus.

Feels-like conditions; however, were similar due to strong and gusty SW winds across mountain ridges-plateaus that made it feel colder than air temperatures.

Wind chills continued to be a factor in how it felt during Thursday, especially at middle to upper elevations above 2000 feet.

Max temperatures varied from around 40 degrees on High Knob and 46 degrees at Nora 4 SSE to 52 degrees at Clintwood 1 W.

Gusty SW-S winds kept most of the day feeling like 30s in Norton and Wise, with 20s to lower 30s across upper elevations ( above 3000 feet in elevation ).

A nice sunset featured mid to high altitude clouds to the south that were beginning to stream northeast in advance of the next weather system to impact the area on Friday.

Conditions tonight remain windy across middle to upper elevations, with air temperatures in the mid 30s to lower 40s feeling like 20s and 30s along mountain ridges.

Focus now shifts to a rather complex setting between a digging northern jet stream ( that will develop the next arctic blast into Sunday-Monday ) and a sub-tropical jet enhanced by this year’s +ENSO.

The high-resolution NAM Model ( above ), as well as the GFS and Canadian models, keep nearly all the precipitation through this evening east of the High Knob Massif and Tennessee Valley Divide while the European Model continues to have more significant rain a little farther west to along the Virginia-Kentucky border.

It is clear on all models that the western edge of the main rain shield will have a sharp cut-off, therefore if it wobbles by only 30 to 50 air miles it will make a difference heading into this afternoon-early evening ( i.e., more significant rain from the VA-KY border eastward if it wobbles west verses little rain if it stays to the east ).

This sharp western edge can already be seen on the moisture blob moving northeast out of the Gulf of Mexico ( above ).

The HRRR Model’s Future Doppler forecast has rain spreading across southwestern Virginia this afternoon from the south and southwest.

Note the broken band of showers to the west associated with the northern stream’s cold front.  The northern & southern stream not phasing, or coming together, to generate a big storm that could be if these two separate featured had merged their energies.

There remains some questions as to how much moisture will be present as colder air arrives into Saturday, then how the northern stream will interact with another system forecast to develop over the northern Gulf of Mexico late Saturday into Sunday.  Stay tuned for updates.

The Bottom Line……

Breezy to gusty winds continue across the higher terrain tonight with a large vertical temperature spread between colder valleys ( temps dropping into upper 10s to low 20s in colder locations ) and milder ridges and plateaus ( 30s to lower 40s ).

*The off-setting factor being wind chills in the 20s and 30s along exposed mid-upper elevation mountain ridges to make it chilly.

A shield of rain spreading northeast from the Deep South will arrive by this afternoon, with heaviest rainfall along and east, or well east, of the VA-KY stateline ( an unknown that will be watched with  forecast model MEANS keeping heavier rains east ).

Regardless of afternoon rainfall, new showers will tend to develop tonight in advance of a cold front approaching from the west.  Air will begin to turn colder overnight into Saturday morning behind this front, with any lingering precipitation changing to snow.  Uncertainty remains regarding how much moisture will be left when this occurs, and with a second system developing over the northern Gulf by late Saturday into Sunday.  Stay tuned for updates.

*Running at a record low snowfall pace for the season to date, odds will continue to favor little snowfall until this setting changes and a more significant system develops.  With northern and southern streams running close, only a little change in either could quickly change the scenario to favor more snowfall.

So far the southern Appalachians, in particular, have been dominated by more westerly winds behind arctic surges with no significant connections to the Great Lakes ( there has not yet been any NW Upslope Flow snowfall with good Great Lake connection ) amid a progressive pattern with up-down temperatures.

Air has instead tended to come into this area from mid-continent, a dry source region, as can be well verified by backwards airflow trajectories.  Meanwhile, the southern stream has either been suppressed too far to the south during January or ejected waves which have passed well west of the Appalachians to keep the mountains amid warm sectors ( to be followed, as just noted, by wrap-around flow dominated by westerly air flow components ).

 Have a great TGIF.