041916 Forecast

My Forecast For Today ( April 17-19 )

Overnight Into Sunday Morning

Clear.  A large vertical temperature spread between colder valleys and milder mid-upper elevation ridges & plateaus.  Winds ESE to SE at 5-15 mph, with higher gusts, along mid-upper elevation mountain ridges ( calm winds in valleys ).  Temperatures varying from frosty upper 20s to mid 30s amid colder valleys to the upper 40s to middle 50s along exposed ridges and plateaus.

Sunday Afternoon

Sunny.  Beautiful blue skies.  Warm.  Rapid temperature rises in valleys.  Winds NE-ENE at generally less than 10 mph.  Temperatures varying from 60-65 degrees at highest elevations to middle-upper 70s at lower elevations ( 70-75 degrees in Norton-Wise and the Sandy Ridge communities ).

Sunday Night Into Monday Morning

Clear.  A large vertical temperature spread between colder valleys and milder mid-upper elevation ridges & plateaus.  Light winds ( NE-N at generally less than 10 mph along ridges above 2700 feet ).  Temperatures varying from 30s in colder mountain valleys, with a chance for frost, to the 50s along exposed mid-upper elevation ridges-plateaus.

Monday Afternoon

Sunny.  Unseasonably warm.  Rapid temperature rises in valleys.  Light northerly winds.  Temperatures varying from 60s in upper elevations ( above 3000 feet ) to 80-85 degrees in lower elevations ( below 2000 feet ).  Mid-upper 70s are expected in Norton-Wise and Sandy Ridge communities.

Monday Night Into Tuesday Morning

Mostly clear.  Large vertical temperature spread between colder valleys & mild mid-upper elevation ridges-plateaus.  Light winds, except N-NW at 5-10 mph, with some higher gusts, along mountain ridges above 2700 feet.  Temps from 30s to low 40s colder valleys to the 50s to near 60 degrees on exposed mid-upper elevation mountain ridges-plateaus.


Weather Discussion ( April 16-19 )

A gorgeous weather pattern for this time of year is being dominated by dry air and large day to night temperature spreads, especially amid mountain valleys.

First Wild Geranium ( Geranium spp. ) Blooms - April 15, 2016
First Wild Geranium ( Geranium spp. ) Blooms – April 15, 2016

Saturday morning temperatures dipped into the upper 20s to lower 30s in colder mountain valleys of Wise, Dickenson, and northern Scott counties, with heavy to patchy frost in many places such as Georges Fork, Meade Fork, Mill Creek, Indian Creek, Norton, Ramsey, Tacoma, etc….the official MIN reached 33 degrees in Clintwood.

Following a Saturday PM MAX of 75 degrees the following temperature drop has occurred in Clintwood tonight ( the official National Weather Service MMTS readings ):

 Clintwood NWS Temperature Readings

4:00 PM
75.0 degrees
7:00 PM
61.8 degrees
8:00 PM
55.9 degrees
9:00 PM
50.9 degrees
10:00 PM
47.1 degrees
11:00 PM
44.3 degrees
12:00 Midnight
42.4 degrees
Air is dry with low dewpoints.  This aids nocturnal temperature inversion formation, via radiational cooling and cold air drainage into valleys, which is actually rather common in the mountains ( i.e., having valleys colder than mountain ridges is rather common at night ).
A weak pressure gradient is also aiding these processes by generating decoupling of light boundary layer winds.  In valleys these light winds are replaced by drainage flows generated by cooling air draining downslope, partly in response to the natural law of gravity, with the drainage flows combining to form stronger flows and even down valley mountain winds within main river valley channels.  This forms a solenoidal circulation, much like the sea breeze does along the coast, with the flow direction of this circulation reversing after sunrise and onset of surface heating. 

University Of Virginia’s College At Wise supported research through coming years will be working to develop a better understanding of micro-climatology of mountain valleys, cold air drainages, and the biodiversity that is associated with gradients within the biologically diverse High Knob Massif and Cumberland Mountains of this area.

*Temperature gradients and true differences associated with this landscape have been, and remain, poorly resolved by computer models and official forecasts for this complex landscape.
For example, the official NWS Forecast:
330 PM EDT SAT APR 16 2016
neglects the colder mountain valleys and the milder mid-upper elevation mountain ridges & plateaus ( temperatures at Midnight being as cold as the official forecast minimums, while exposed middle-upper elevation ridges and plateaus will never drop down to this forecast range ).
A Species of Jumping Spider On Wild Geranium
A Species of Jumping Spider On Wild Geranium
This spider has 4 eyes in front, 2 in the middle and 2 in the back of his head.  There is no way anything will “sneak” up on this simply amazing design of nature.  He was “watching” me from this Wild Geranium leaf upon which he is standing.
The High Knob Landform and Clinch-Powell river basins are a core hotspot in the continental USA for the rarity & richness of limited range species, with truly extraordinary terrestrial & subterranean biological diversity.
Beetle Species In Woods - Late PM of April 16, 2016
Beetle Species In Woods – Late PM of April 16, 2016
Like many true insects, this species has a pair of compound eyes and a pair of simple eyes ( the simple eye being just above and a little to the right of his compound eye visible from this side ).

Conditions are unseasonably dry, for what is often one of the wettest times of the year, with this being reinforced once again by another blocking pattern ( the second major block of the flow field since March 1, 2016 to impact the southern Appalachians and eastern USA ).

Rain chance will eventually return, by later in the work week.  Until then, enjoy this gorgeous weather ( just be prepared for some huge day-to-night temp differences if you live or work-play amid mountain valleys ).

Have a great Sunday.

It should be noted that Dr. William ( Bill ) Gray passed away Saturday ( April 16 ).  A legendary forecaster-researcher of hurricanes and tropical weather-climate patterns.  A true pioneer of his field.  May God Bless the Gray family.