ALERT For Heavy To Excessive Rainfall At Times From This Week Into Next Week Amid A Persistence Pattern
Severe Thunderstorm Watch In Effect Until 9:00 PM
Severe Thunderstorm Watch In Effect Until 9:00 PM FridaySevere Thunderstorm Watch Discussion
The Storm Prediction Center Has Issued A Enhanced Risk For Severe Thunderstorms Through Friday PM Into Friday Night – Main Severe Risk Is Wind Damage
Storm Prediction Center Updated Risk RegionsStorm Prediction Center Updated Discussion
A heavy to excessive rainfall potential with the possibility of dangerous flash flooding will continue to be a weather concern, especially from the Cumberland Mountains north and west, in coming days as waves of showers & downpours in thunderstorms periodically move across the region.
While many dry hours will occur, with a break from active storm clusters for at least part of this weekend, the storm pattern renews into next week. Accumulative rain amounts over time will saturate the ground and make later activity more likely to cause water problems ( especially with any training or back-building of convection which occurs ).
These statements are based on recognition of a repetitive synoptic-scale weather pattern and recent ( antecedent ) conditions producing numerous flash floods in the region.
Remainder Of Thursday Afternoon
Partly to mostly cloudy with scattered showers. Chance of thunder. Areas of dense fog across upper elevations. Winds W-NW 5-15 mph, with higher gusts. Temperatures varying in the 60s to lower-middle 70s ( warmer to the south into the Great Valley and Tri-Cities ).
Thursday Night Into Friday Morning
A chance of showers & downpours in thunderstorms. Winds SW-W 5-15 mph on mountain ridges-plateaus below 2700 ft. WSW-WNW winds 10-20 mph, with higher gusts, on upper elevation mountain ridges. Humid with temperatures in the 60s to around 70 degrees.
Friday Afternoon
A chance of showers & downpours in thunderstorms. Some storms could be strong to severe with damaging winds and hail. Winds SW to W 5-15 mph, with higher gusts. Humid & hazy with temperatures varying from 70s to lower-middle 80s ( warmer south toward the TRI ).
Friday Night Into Saturday Morning
A chance of showers & downpours in thunderstorms. Some storms could be strong to severe with damaging winds and hail. SW to W winds 5-15 mph on mountain ridges-plateaus below 2700 feet. WSW-WNW winds 10-20 mph, with higher gusts, along upper elevation mountain ridges. Humid with temperatures in the 60s to lower 70s.
Weather Discussion ( July 5-9 )
Early Friday Afternoon
A dangerous severe thunderstorm-heavy rainfall setting is taking shape for the Mountain Area this afternoon into this evening ( Friday July 8 ).
Wind damage and power outages will be a significant threat along with any storms that train or back-build to generate very heavy rainfall ( even weak looking showers on Doppler have had downpours today as the air mass is water loaded ).
Warnings will be likely for some of this activity, so please remain alert to changing weather conditions.
Previous Discussion
Some majestic cloud formations have been observed through Thursday as abundant moisture and W-NW flow have combined to keep low clouds ( dense fog ) and many showers going across the High Knob Massif area.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Rainfall totals during this first week of July ( during the past several days ) have now reached around 3.00″ or more in upper elevations of the High Knob Massif, with widespread 1.50″ to 2.50″ amounts being observed across surrounding locations within Wise and Dickenson counties.
*Southern Kentucky and portions of middle Tennessee being the most recent targets for flooding rains.
Nora 4 SSE – NWS Station In Middle Elevations ( Elevation 2650 feet )
Temperatures Thursday have remained in the 60s across mid-upper elevations above 2600 feet, with lower-mid 70s at low-middle elevations along and north of the High Knob Massif and Tennessee Valley Divide.
Black Mountain MesoNET Up To 1:45 PM Thursday – July 7, 2016
As of 4:42 PM ( July 7 ) the official MAX had reached 74.6 degrees at Clintwood 1 W in the Russell Fork Basin ( elevation 1560 feet ).
*The official MAX in Clintwood ended up reaching 76.1 degrees ( the July rainfall total climbing to 1.65″ ).
NASA Visible Image At 4:00 PM Thursday – July 7, 2016
Focus now shifts toward additional storm clusters that are being forecast to develop overnight into Friday in advance of an approaching upper trough and surface front.
Storm Prediction Center Risk Regions – 8 AM Friday to 8 AM Saturday ( July 8-9 )Storm Prediction Center Discussion
While a slight risk for severe thunderstorm development has been issued for the period from 8 AM Friday to 8 AM Saturday, recent runs of the HRRR and RPM models are showing overnight storm development.
HRRR Model Future Doppler Radar Forecast At 4 AM Friday – July 8, 2016HRRR Model Future Doppler Forecast At 8 AM Friday – July 8, 2016
Time will soon tell if these models are correct in this overnight storm development, with local 1.00″ to 4.00″+ rainfall amounts predicted.
*Remember is it difficult for models to handle convection, such that placement and timing of storms and MAX rainfall amounts prior to actual storm development is subject to change.
HRRR Model Forecast Rainfall Amounts Next 15-Hours
The threat for additional strong-severe thunderstorms in advance of a surface front must be respected by later Friday into Friday evening.
Please stay tuned to NOAA Weather Radio and your favorite media sources for possible watches and/or warning that may be needed.
