063016 Forecast

Mountain Area Forecast ( June 28-30 )

Overnight Into Tuesday Morning

Hazy & humid with light rain & drizzle.  Areas of dense fog, most widespread in locations along-north of the High Knob Massif & Tennessee Valley Divide.  Winds NW-NE at 5 to 15 mph along mid-upper elevation mountain ridges.  Temperatures widespread in the 60s.

Tuesday Afternoon

Partly sunny.  Small chance of a localized shower.  Skies becoming blue with decreasing haze late.  NW winds 5 to 15 mph.  Temps varying from low-mid 70s to lower-middle 80s ( coolest at highest elevations ).

Tuesday Night Into Wednesday Morning

Mostly clear.  NNW-NNE winds decreasing to generally less than 10 mph by morning on mountain ridges.  Temps from lower 50s to lower 60s.

Wednesday Afternoon

Partly to mostly sunny.  Beautiful blue skies with northerly winds 5-10 mph.  Temperatures varying from 60s at highest elevations to the middle 70s to around 80 degrees.

Wednesday Night Into Thursday Morning

Mostly clear.  Chilly in mountain valleys.  Light N-NE winds.  Temperatures varying from upper 40s to mid 50s in cooler mountain valleys to the upper 50s to lower 60s.

Thursday Afternoon

Partly cloudy.  Pleasant.  Small chance of a shower or thunderstorm.  Northerly winds generally around 10 mph or less.  Temperatures varying from 60s to lower 70s at highest elevations to the upper 70s to lower 80s.

A stormy weather pattern is likely to develop by the Independence Day Holiday Weekend into next week as heat & humidity increases to establish a temperature-moisture gradient across the region.  A heavy to locally excessive rainfall potential is being monitored for portions of the Mountain Region.  Stay tuned for later updates.


Weather Discussion ( June 27-30 )

Wednesday Evening ( June 29 ) Update

A gorgeous late June air mass graced the Cumberlands during June 29, with 50s to lower 60s in the morning giving way to pleasant 70s to around 80 degree afternoon temps.

Shallow Morning Fog In Powell Valley
Shallow Morning Fog In Powell Valley of High Knob Massif – June 29, 2016

Latest model runs are showing a better Holiday weekend for the Mountain Empire than in previous days, but a chance of hit-miss showers and thunderstorms will exist.

European Model 51-Member Ensemble MEAN 850 MB Temp Anomalies
European 51-Member Ensemble MEAN 850 MB Temp Anomalies DAYS 1-5

The operational European Model has come more in line with the MEAN of it’s 51-Member Ensemble group, with a shift to the north with the heaviest rainfall axis into next week.

European 51-Member Ensemble MEAN 850 MB Temp Anomalies
European 51-Member Ensemble MEAN 850 MB Temp Anomalies DAYS 6-10

While this might have been predicted from feedback of drought developing across the Tennessee Valley and parts of the southern Appalachians, it remains in flux and the Cumberland Mountains remain in play for the potential of heavy to excessive rainfall amounts next week ( along with locations to the north into the Ohio Valley & West Virginia ).

This recent trend does not bode well for flood ravaged West Virginia, with many praying for this current drying period to continue through the extended.

The Updated Bottom Line…While a chance for showers and thunderstorms will return from Thursday-Friday through the Holiday Weekend, recent model runs are not looking as wet as in previous days.

A very stormy period continues to be likely in the extended 5-10+ day interval, with a heavy to excessive rainfall potential looming for portions of the Ohio Valley and Appalachians.  Again, at this time, the precise corridor of main impact can not yet be determined despite a general shift northward by MEAN model guidance away from the Tennessee Valley ( the Cumberland Mountains remain in a potential target zone of training storm clusters ).

Stay tuned for later updates as models continue to work to figure out the pattern into the first week of July 2016.


Previous Discussion

Reference My 062716 Forecast Discussion for recent data on the West Virginia flood disaster.
While the terrible June 22-23 flood is being called a 1000 year event, it is important to note this may be true only in the corridor impacted. Many severe flood events have occurred in the Appalachians, with one of the worst and most widespread events striking during April 1977 ( 40 years from this coming April ).
Reference Flood Of April 1977 In The Appalachian Region for details on a major event that was much more widespread in coverage along the Appalachians, with 47 counties declared Federal Disasters along with 22 fatalities.  Many communities  across Wise, Lee, Dickenson, Buchanan, Scott, Bell, Harlan,  Letcher and Pike counties were devastated in addition to numerous communities in southwestern West Virginia.

Showers and downpours in thunderstorms developed to begin the new work week on June 27, with local rainfall totals topping 1.00″ in places.  Afternoon cloud bases lowered to obscure high ridges amid the high country.

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

While light rain, drizzle and low cloud bases linger tonight a drier and simply gorgeous stretch of weather conditions is expected to rule the mountain landscape during mid-week.

This period of weather should be enjoyed.

Rosebay Rhododendron
Rosebay Rhododendron Following Thunderstorms – June 27, 2016

It is becoming clear in the modeling that another stormy period is upcoming as a temperature-moisture gradient again sets up a boundary along which clusters of showers and downpours in thunderstorms will roam.  Since the air mass to the south has not changed, this is worrisome given a high precipitable water air mass will be nearby.

European Model 51-Member Ensembles
European Model 51-Member Ensemble MEAN 500 MB Height Anomalies
This will be more of a WNW-ESE or W-E setting with thunderstorm clusters moving along the gradient.  What is yet to be determined is exactly where the gradient sets up.
European Model 51-Member Ensemble
European Model 51-Member Ensemble MEAN 850 MB Temp Anomalies

The early trends seem to be ones to focus more on the southern Appalachians and Tennessee Valley versus locations flood ravaged in SE-Central West Virginia.

However, it is just too early to tell for sure.  More should be known in a few more days as initial action begins to form by late in the work week and the weekend.

The Bottom Line…A simply gorgeous mid-week stretch of weather conditions will give way to another stormy period by the Independence Day Holiday & next week.  The threat for heavy to excessive rains could again arise as a gradient sets up across the region with return of a high moisture content air mass, but the location of this can not yet be determined.

Stay tuned for updates in coming days.