ALERT For Ponding Of Water Along Roadways And For Dense Fog Development Into Middle Elevations Along And North Of The High Knob Massif Into Saturday AM
Run-off from moderate-heavy Friday rainfall has caused ponding of water along roadways. Slow down and be extra careful. In addition, low cloud bases are currently causing widespread dense fog at elevations above 2900 feet. Expect lowering of cloud bases overnight into Saturday Morning, to around or locally below the elevation of Wise, on rising northerly air flow along & north of the High Knob Massif.
Former Alerts:
The Storm Prediction Center Has Issued A Slight Risk For Severe Thunderstorm Development Thursday PM Through Thursday Night
Wind damage will be the primary threat with any strong to severe thunderstorms Thursday Afternoon & Thursday Night. Otherwise, heavy rainfall will be a concern from Thursday Evening Through Friday Night. Folks living and/or driving through low lying and flood prone locations should remain alert for ponding of water and strong rises on streams. Never drive through a flooded road, TURN AROUND and DO NOT DROWN.
While a Flash Flood Watch is officially in effect through Friday for Dickenson and Buchanan counties, adjacent locations across Wise, Scott, Lee, and Russell counties will also be at risk for strong rises on creeks and rivers.
Stay tuned to NOAA Weather Radio and your favorite media sources for possible warnings and additional watches that may be needed through Friday.
Remainder Of Thursday Afternoon
Partly-mostly cloudy. Chance of showers & thunderstorms, especially in portions of Dickenson and Buchanan counties. Gusty. SW-WNW winds at 10 to 20 mph, with higher gusts. Temperatures varying from 60s in upper elevations of the High Knob Massif to the upper 70s to lower 80s.
Thursday Evening Through Friday Morning
Showers & thunderstorms becoming likely. Some storms could be strong to locally severe. Downpours of heavy rain. Winds becoming SSE-SSW and diminishing overnight into morning. Areas of dense fog. Unseasonably warm with temperatures widespread in the 50s to around 60 degrees.
Mid-Morning Friday Through Friday Afternoon
Showers & thunderstorms. Locally heavy rainfall possible. Light and variable winds becoming northerly. Low clouds with widespread dense fog in upper elevations ( orographic cap clouds ). Temperatures varying from 50s at the upper elevations to the 60s within middle and lower elevations.
*Lowering cloud bases and dense fog will become a factor at middle to upper elevations during Friday Night into Saturday AM, with the potential for cloud bases to drop downward across the Wise & Sandy Ridge plateaus ( to around or below 2500 feet ) on upsloping northerly air flow toward the High Knob Massif.
Friday Night Into Saturday Morning
Showers to drizzle. Turning chilly. Low clouds with dense fog from around the elevation of Wise upward in elevation. Winds NNW to NNE at 5-15 mph, with higher gusts. Temps dropping into 40s to around 50 degrees ( near 40 degrees at summit levels of the High Knob Massif ). Wind chill factors in 30s and 40s ( coldest at highest elevations ).
Saturday Morning Through The Afternoon
Low clouds-fog-drizzle during the morning ( especially at higher elevations ) giving way to partly-mostly sunny skies during the afternoon. Winds NW-N at 5-10 mph with higher gusts. Temperatures varying from the lower-middle 50s in upper elevations to the 60s ( warmer to the south within lower elevations of the Great Valley ).
Saturday Night Into Sunday Morning
Large vertical temperature spread developing between colder valleys and exposed mountain ridges & plateaus. Mostly clear evening skies, then increasing clouds possible overnight into morning. Winds becoming WSW to WNW at 5 to 15 mph, with higher gusts, along exposed middle-upper elevation mountain ridges. Generally light valley winds. Temps varying from 30s to lower 40s in mountain valleys to the upper 40s to low-mid 50s.
Weather Discussion ( Changeable )
Changeable is probably the best way to describe weather conditions through upcoming days, with the first order of business being a developing cluster of thunderstorms that will move across the mountains Thursday evening.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Although temperatures are mostly in the 60s ( upper elevations ) and 70s ( middle elevations ) to lower 80s ( lower elevations and or places under downsloping air flow ), there is a notable haze and increase in low-level moisture in advance of developing thunder-storms upstream of the mountains.
Storm Prediction Center Risk Regions
A few storms currently have warnings on them in Kentucky and this will be a trend to watch through the remainder of this afternoon into this Thursday evening as a cluster of thunderstorms ( MCS or Mesoscale Convective System ) comes together over the foothills and mountains.
Jackson Kentucky Doppler At 4:22 PM Thursday ( May 11 )
Cloud tops are growing vertically and expanding upstream, and while a wind damage potential does exist the threat for heavy rainfall will certainly be a concern with more rounds of showers-thunderstorms expected Friday.
NASA Visible With Watch-Warning Overlay
With convection it is always difficult to pinpoint places receiving heaviest rain amounts, but the signal is clear.
NAM 12 KM Model Rainfall Forecast Next 60-Hours
Locally heavy rainfall amounts are likely through Friday.
NAM 3 KM Model Total Precipitation Forecast To 8 AM Saturday – May 13
Following a cooling trend behind all this mess into this weekend, with chilly temperatures in mountain valleys being notable Saturday evening into Mother’s Day morn, major warming will become the theme next week.
European 51-Member Ensemble MEAN 500 MB Height Anomalies: Days 6 to 10
A big trough developing over the western USA will pump up heights across the eastern states and generate anomalously warm conditions for a good portion of next week.
European 51-Member Ensemble MEAN 850 MB Temp Anomalies: Days 6 to 10
*Nights may continue to be cool in mountain valleys if winds are light, but days are clearly trending toward being unseasonably warm for this time of year during next week.
