062017 Forecast

Mountain Area Forecast ( June 20-22 )

ALERT For Heavy Rainfall Potential Friday Into Saturday For The Cumberland Mountains

Overnight Into Tuesday Morning

Mostly clear.  Areas of dense valley fog.  Winds WNW-NW at 5-10 mph, with some higher gusts, on mid-upper elevation mountain ridges.  Temperatures varying from the 50s to near 60 degrees, except upper 40s to lower 50s within colder valleys at upper elevations ( above 3000 ft ).

Tuesday Afternoon

Partly sunny ( some increase in clouds during late PM ).  Light SSW-WSW winds.  Temperatures varying from upper 60s to lower 70s within upper elevations to the upper 70s to lower 80s ( warmer south into the major river valleys ).

Tuesday Night Into Wednesday Morning

Partly cloudy.  Light winds.  Temperatures varying from low-middle 50s in cooler mountain valleys to the lower to middle 60s along exposed ridges and plateaus.  Areas of dense valley fog.

Wednesday Afternoon

Partly-mostly cloudy.  SW winds 5-10 mph, with some higher gusts.  Temperatures varying from upper 60s to lower 70s at upper elevations to the upper 70s to low 80s.

Wednesday Night Into Thursday Morning

Mostly cloudy ( high cloudiness ).  SSW-WSW winds 5-10 mph, with higher gusts, on mid-upper elevation mountain ridges and plateaus.  Temperatures varying from the 50s to mid-upper 60s ( warmest mid-elevation thermal belts ).


Weather Discussion ( Evolution )

Predawn Of Wednesday ( June 21 ) Update

The rainfall forecast range from a host of different models and ensembles are predicting potential totals of from 2.00″ to 6.00″+ across the mountain region.  This has come down significantly from initial model projections, but remains worrisome given that orographic forcing continues to be shown as a factor ( gradient and low-level jet winds ).

Model Cluster Track For Cindy And Remnant Core

Stay tuned for continued updates on this system.


Previous Discussion

A nice afternoon finally graced the mountain landscape in wake of the latest rounds of showers & thunderstorms, with much less humid air being felt ( and improved visibility ).

High Knob Massif Webcam – University Of Virginia’s College At Wise
A spectacular sunset illuminated the early evening.
High Knob Massif Webcam – University Of Virginia’s College At Wise

An evolving weather pattern is the best way to describe late week into this upcoming weekend and early next week, as a radical shift in the flow regime across the eastern USA will occur.  Complicating this major change will be a developing tropical system in the Gulf of Mexico and its remnants.

European 51-Member Ensemble MEAN 500 MB Height Anomalies: Days 1-5

The forecast MEAN of the European Ensembles has a notable break in the heat ridge across the southern USA, offering a possible route for movement of tropical remnants lifting out of the Gulf of Mexico late this week into this weekend.

The cluster of many different models ( below ) agree and use this break amid the heat ridge as a pathway for movement, with this system being heavily loaded on its eastern side ( i.e., the flooding rainfall potential will be greatest along and east of its centroid ).
Forecast Model Cluster On Forecast Track Of Tropical Moisture

The model cluster initialized at 00z ( 2000 hours ) on Monday ( June 19 ) was in generally good agreement in lifting the tropical system ( possible Cindy ) toward the mouth of the Mississippi River, before recurvature to the north and northeast occurs in advance of the developing and digging Canadian trough.

Official National Hurricane Center Track

Although it is far too soon to know how much rain will fall, some scary rain numbers are already coming out of forecast models with the Monday Night European placing flooding 5.00″ to 10.00″ rains over southeastern Kentucky and far southwestern Virginia.  The 00z Canadian ( GEM ) is very similar and a little more expansive with 5.00″ to 10.00″ rain amounts extending from middle Tennessee across Kentucky into far southwestern Virginia.

The greatest concern is that the remnant moisture plume will interact with an approaching cold front and upper air trough.  That would be a worst case scenario over complex terrain.  The good news, this remains days away and there is plenty of time for changes in this current forecast.  The bad news is; however, that such a moisture plume is likely to cause flooding rains some where across the region.

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

The magnitude of this upper trough and amount of cold air for early summer is impressive.  Add in an approaching tropical system and it has the potential of becoming a headline, or history, making event.  

Exactly how & where this evolves is to be determined.  Please stay tuned to NOAA weather radio and your favorite media sources for updates.